The pi - pi pi process in nuclei and the restoration of chiral symmetry
π-π弱相互作用
In the arrangement of aromatic rings one can distinguish generally between a stacked arrangement and an edge- or point-to-face, T-shaped conformation (Fig. 1). The T-shaped conformation is a C–H ؒ ؒ ؒ π interaction.20–22 Stacking does not necessarily have to be a perfect face-to-face alignment of the atoms but can also be an offset or slipped packing. Both face-to-face and T-shaped conformations are limiting forms in aromatic interactions. Among these, the stacked (facial) arrangements are of particular interest as π–π interactions. A sizeable number of theoretical and experimental studies have been performed to understand the nature of π–π interactions. While there is considerable experimental evidence on the structure and property influencing character of these interactions, their true nature is still a matter of some discussion.3,5–7,12 The following electrostatic or van-der-Waals interactions are discussed as intermolecular forces 23 for the stabilization of π–π interactions between closed-shell molecules;5,24 (Fig. 2 gives a pictorial summary of the interactions). (a) Dipole– dipole (electrostatic) interactions: the interactions between the different permanent and static molecular charge distributions. (b) Dipole–induced-dipole interactions between the static molecular charge distribution of group A with a proximityinduced change in charge distribution of group B. (c) Induceddipole–induced-dipole (London) dispersion interaction: the instantaneous dipole moment from a fluctuating electron cloud polarizes a neighboring molecule and induces in it also an instantaneous dipole. These van-der-Waals interactions (a)–(c) are inherently attractive and their potentials fall off rapidly with distance by 1/r 6. (d) Pauli repulsion: at very short distances the filled electron clouds of the interacting molecules begin to overlap and the (Pauli) repulsion between the electron shells J. Chem. Soc., Dalton Trans., 2000, 3885–3896 3885
英语学习强核力
The strong nuclear forceNuclear force Strong, which binds the protons and neutrons in the neutron, and binds the protons and neutrons in the atom together. In general, another spin of the glue is considered to carry a strong force of 1 particles. It can only interact with itself and with the quark. The strong nuclear force has a peculiar property called confinement: it is always put into particle bound combination without color. Because of the color of the quark (red, green, or blue), people can't get a single quark. On the other hand, a red quark must be bound together with a bunch of glue and a green quark and a blue quark (red + Green + blue = white). This constitutes a proton or neutron triplets. Other possibilities are the opposite of a quark and an anti quark pair (red + anti red, or green + anti green, or blue + anti blue = white). The combination of such a particle is called a particle. Meson is unstable, because the quark and antiquark can annihilate each other and produce electrons and other particles. Similarly, because of the color of the plastic, color confinement makes it impossible for people to get a separate gel. On the contrary, people can get the gluons, the colors add up to white. Such a group formed an unstable particle called a colloidal sphere. Also, the strong nuclear force and the electromagnetic force, the weak nuclear force is by anti gravity differentiation and section 1.2 electron positron colliding into a virtual photon, if the collision energy is relatively low, virtual photons will become a pair of electron positron pairs or a pair of Mu Zi, if energy is high virtual photons will become a pair of positive and anti quark, when the energy just reached a vector particles near the mass (known as the vector particles produce threshold), the quark antiquark to form a bound state, if high energy is resonance can not be formed, the quark antiquark will back to behind fly away from open. Proton group of quarks and the other a proton (or antiproton) in the antiquark transformed virtual photon, and virtual photon produces a pair of lepton. This process just and Lepton on transformation produced Quark to the contrary. Photons can by proton and anti proton or positive and negative electrons collide, transformation and, in turn, photon collision can also transformed into a proton and anti proton or positive and anti electrons, and positive and negative electron can be transformed into positive and anti neutrinos. The process is reversible and hyperons and mesons all unstable particles will decay into photons or neutrinos, so the combined into photons, electrons, neutrinos, and quarks, protons, neutrons, and all unstable particle structure materials are the same, that is anti gravitons and the graviton. All particles like put in different size cup of water, will be two different cups of water (two particle) pour together can form the other a cup or two of water (the other one or two particles), anti atomic gravitons and gravitons, like water, and in nuclear fusion, nuclear fission in the atomic mutual conversion of similar, and the principle is the same. Particles can not be the most basic unit of matter, the most basic unit of matter has a necessary feature: no matter how hit it will not be converted or broken. And the interaction between particles is very frequent. The strong nuclear force, the weak nuclear force in the nuclei in the vicinity of force mechanism is a kind of short-range force, but the short-range force to outside influence all transforming growth Chengli, photon as the carrier, such as solar radiation huge energy comes mainly from the strong nuclear force. So can the strong nuclear force, the weak nuclear force and the electromagnetic force is a process that transformed from short to long, the short-range force as in atomic force mechanism, atomic likened to a gun, gun using a gunpowder, but with a different amount of gunpowder, ignited gunpowder method with (in different force mechanism of the strong nuclear force and the electromagnetic force, the weaknuclear force), but the bullet are the same, the photons corresponds to the bullets in the gun. Transfer the strong nuclear force PI ~ meson, transmit the weak nuclear force neutral bosons (Zº) quickly decays into photons, PI + and PI - collision will be converted into photons, W + and W - collision will be converted into photons, and transfer the electromagnetic force is photon, so in the photon, the strong nuclear force and the electromagnetic force, the weak nuclear force is not, is the unity and PI +, PI & ordm; and photons, W +, Zºanti gravity and resistance to the gravity of homomorphism. Photon can generate positive and anti quarks, positive and anti electron, positive and anti quarks can generate positive and anti protons, neutrons and other baryon, positive and inverse electron collision can generate positive and anti neutrino is photon anti gravity can differentiate into the strong nuclear force and the electromagnetic force, the weak nuclear force. Section 1.3 for proton and electron production line under the appearance of particles in the ever-changing world hidden a particle materials into each other procedures, or particle transformation rules, like a production line, we know that industrial production line is in the execution of a computer program. Raw materials for the production of the "proton and electron production line is a proton, electron, energy is gravity, the strong nuclear force and the electromagnetic force and weak nuclear force, the production line of the final product is stable photons and neutrinos. Proton, electronic production of neutrons in nuclear fusion, nuclear fission has an important role, like gun firing pin, the pipeline necessary to destroy the agent. In addition to protons, electrons, neutrons, photons, neutrinos of all particles are in the process of production of semi-finished products, so they are very unstable, short life, eventually converting or production or photons or neutrinos, we found in a variety of accelerator new particles are the line in the production process of the semi-finished product, this line but also the excess production of raw materials "of protons, electrons," spit it out. Stability is the normal state of the universe, such as particles, atoms, molecules and so on, and all kinds of unstable particles are the intermediate states in the process of production. In different energy level of the accelerator produced many make dazzled the chaos of semi-finished products (various unstable particles), we never can be puzzled by the appearance, in fact, just protons, electrons in different energy environment execution of different procedures, like with different force shaking "Kaleidoscope", you can see kaleidoscopic gostop (in the whole particle family), but in fact "Kaleidoscope" just by a few pieces of coloured paper composition (the equivalent of protons, electrons and photons, neutrinos stable particles). Under certain conditions, this production line can be reversed, that is, photons and neutrinos can produce electrons and protons, the most common is the photon collisions can produce positive, anti electron or positive, anti proton. In the field of natural science, the simplest explanation is often the right one. The nature of the universe is simple. A fast not like in the middle of the illusion of the illusion of 1.4, material substance can take electric fan analogy, an atom is like a fan, atomic nucleus like motor nuclei of electronic electric fan blade, when the electric fan rotates, we can see the fan leaf next to the most of the space is empty, if electric fan rotates, we saw blade next to the space by the blade rotates to form a phantom filled, if the electric fan to the highest speed increased by 1 million times, we simply don't feel to the leaves in the rotation, and when the blade is shaped into the illusion is a textured material. And actually atomic illusion is much higher than the electric fan of the phantom, 1/107 atomic nuclei and electrons in an atom space only motor and vane in electric fan illusion space, but it is electronic to close to the rotational speed, the speed is blade speed 3 x 1010 times, any visible matter are like countless miniature electric fan along with the rapid rotation of illusion. Illusion ofsubstance, from the X-ray and gamma ray high penetration of, we see the X-ray imaging is formed by the illusions of material after being pierced, and neutrinos can through the greater thickness of the illusions of material. Section 1.5 graviton level, odd sub grade matter mass energy equation from atomic foam structure is knowable, support atomic foam, foam particle, the graviton bubble speed. From point of view of the structure stability, anti gravitons and gravitons must be many times more than the speed of light, in order to maintain the electron, photon bubble?Female widows of monopolizing cylinder Yu widows woo Chi Yong brain chanting Xing Minamata deficiency must be hazy light famine Aini shoot Qi Zhong psi printing more hasty psi and beans sell Nai que cylinder Yu curl up famine illegal chanting mechanical tomb Dayu and mechanical Tom hurried psi woo guanidine psi right color and blame famine illegal chanting school gun Dayu glaze Dang chanting brother reeling inferior straight laid callus gongs? What is the speed of light is the materials of the order of the particle's speed limit? Will exceed the speed of light caused by super speed of light photon graviton and anti gravitons operation because of the unstable, the instability could so that the photon is running slow, when photons back to the speed of light, return to the optimum condition of the photon graviton and anti gravitons run, that is the reason for the constancy of the speed of light, the constancy of the speed of light of more photonic structures. In close contact with the graviton superluminal and odd sub super superluminal and the author puts forward the following questions. Why the atom as a "perpetual motion"? Why are the atoms so long? What is the energy that sustains the electrons to be near the speed of light and revolves around the nucleus of the nucleus more than 1033 years? If is nuclear energy (known to the highest energy), e = MC2 equation, the atom will be in 300 years to deplete energy, electronics into the nucleus of an atom, which is obviously absurd, even according to the Bohr assumptions of electronic operation not to external radiation energy, that is a rotating electric power source. Why is the energy of the class so big? Where does the energy come from? Three times the mass of our sun the black hole in the collapse process experienced the stage from star to white dwarfs, neutron star to a black hole, through the atoms broken bubble, bubble particle crushing, atomic foam electronic speed of light (c) and atomic speed limit (H) (that is, more than the speed, electrons will from the nucleus of an atom), and has cut tight relationship is supported on the bubble particle anti graviton speed (b), from the perspective of structure stability, only c/h is less than or equal to B / C in order to maintain the photon and electron in the speed of light structural stability, so Graviton matter must be superluminal. The graviton material mass energy equation of E2=mb2, which is a huge source of energy of quasars. The center of a class of stars is a large black hole, the energy of the solar energy is 1016 times that of the solar nuclear fusion energy, and the mass energy equation of the particle mass is E=mc2. And it can be inferred that the velocity of the graviton matter and (b) probably equivalent to 107 - 108 times the speed of light, in the face of this speed, it is no wonder that Newton believed gravity is the ultra distance effect, but also makes the Einstein in EPR dispute that, between the speed of light particles are "spooky action at a distance". Atomic speed limit "H" determination: take three times the mass of our sun star can poly synthesis of the heavy atoms, such as carbon, oxygen, nitrogen, these atoms placed in vacuum environment maximum speed accelerated to all electron from the nucleus of an atom. Is an unstable Galaxy formed in the early period of the big bang (about 10000000000 years ago), when it was a flourishing period, not only in quantity, but in a large amount of energy and intense activity. The center of these quasars have a quality with respect to the stability of a supermassive black hole at the core is smaller blackholes, after the crushing of the quasars at the center of a black hole can not be completely absorbed a lot of stellar matter (atoms and particles) transformed into graviton, so undigested part of the particles at close to the speed of light and superluminal anti graviton flow from the gravitational field of a black hole at the two ends of the shaft discharge, so that the quasars at close to the speed of light 0.9c) running in space, if there is no anti gravitons with a graviton superluminal could not make the giant quasar at close to the speed of light. In the quasar appeared two kinds of energy and burst, the first is of stars around a black hole will be its nuclear poly strain rate increased nearly 100 times, the second is black hole crushed particles after failed to effectively all anti gravitons transformed into graviton, the anti gravitons from the gravitational field of a black hole at the two ends of the shaft discharge, obey E2=mb2 equation, this part of the energy is the largest. But in the end it will be the black hole's gravitational field to win. Quasars and active galaxies, and stable galaxy center has a jet of material phenomena, this phenomenon of jet and the center of the galaxy black hole mass has great relationship, the small black hole mass, multiple jets, a supermassive black hole, jet, because most of the particles and anti gravitons have been gravitational field of a black hole into graviton. Graviton bubble is extremely difficult to crush, and is even 1015 solar masses of the giant black hole cannot be graviton crushed only when consumed most of the matter in the universe of the black hole in the universe to the graviton is crushed, so that the gravitons collapse into positive and negative odd subgraphs. The speed of support material, foam, the odd sub must be ultra light foam to support them. The author puts forward the supporting graviton foam positive and anti odd sub speed a is equal to b) multiplied by the total mass of the universe (1056) and divided by three solar masses (1034), approximately equal to B x1023. That the son of a strange substance mass energy equation is E1=ma2. The is atomic electrons around the nucleus of an atom 1033 years the inexhaustible source of power, which is a big bang super energy source (the lower limit of the lifetime of atoms is from the "proton lifetime" experimental derived). Section 1. The 6 question as Newton out a seemingly innocent question, why Apple would fall on the ground? Finally found the "gravity", the author raised questions about some people turn a blind eye to the phenomenon, the gravitational pull of the sun, why so big? It is because of the mass of the sun that the sun is made up of? The sun is made up of hydrogen helium atoms. It is obvious that the total mass of the sun is equal to the sum of the atomic mass of the sun. In the sun, the strong nuclear force and the electromagnetic force and weak nuclear force moment in and gravitational counterbalance (in the "gravity" is refers to the "gravity", the same below), and the strong nuclear force and the electromagnetic force, the weak nuclear force and must be equal to the gravity, the star will not be gravitational collapse, to maintain the sun stable (the strong nuclear force and strength, strong interaction, the electromagnetic force also known as electromagnetic interactions, the weak nuclear force and weak force, and the weak interaction). The strong nuclear force and the electromagnetic force and weak nuclear force to generate an outward force, gravity inward force, four against the formation of long-term balance, namely "gravity = the strong nuclear force, electromagnetic force + + weak nuclear force". The strong nuclear force, electromagnetic force, the weak nuclear force are in the atom, the gravity must also exist in atomic, the sun's gravity is equal to which each atom output and gravity. In the macro universe, we really attraction, the strong nuclear force, electromagnetic force, weak nuclear force four, gravity is the most powerful, it in the four forces of the universe always dominates, in its formation of galaxy clusters, galaxies, solar system, stars, planets, it makes billions of stars aroundthe Galactic Center of rotation, it will be the sun bound into a blazing fireball, it makes every one of us can live on the earth. It makes everything in the universe can exist. Gravity in the macro in the universe always dominates, the macroscopic material is composed of micro material, the protagonist in the universe "stars" and "planet" is made up of atoms, that gravity must exist in atoms and each atom of gravity is equal to the atoms of the strong nuclear force and the electromagnetic force and weak nuclear force. From the stars to the evolution of white dwarfs, neutron stars, black holes, we can see gravity in the confrontation with the strong nuclear force and the electromagnetic force, the weak nuclear force, and gradually achieve victory, and, ultimately, the strong nuclear force and the electromagnetic force and weak nuclear force and gravitation unified, become pure gravity of the black hole. Gravitation is the most powerful existence of the universe. In the universe of stars and planets are gravity and the strong nuclear force, electromagnetic force, weak balance of the nuclear force of the unity of opposites, and they constitute the visible universe. Why is this one of the earth's microscopic substances in the universe dominated by gravity to be missing? This is just a problem of human cognition, gravitation is everywhere. People will gravity out of the material and micro, that gravity micro material negligible, is bound to repeat the mistakes of the "geocentric", both of which are by means of scientific observation made a wrong judgment. According to the logic of the existing theory of the atom, if the sun is divided into numerous basketball sized objects, that the basketball sized objects the total gravitational becomes only the strong nuclear force 1/1040. This apparently absurd. Reasonable?Have a wisdom and X Kang shovel guide school x Kang mixing treatment of bran left male with private heirs also loyal t Ting x PA Kang to throw Dang Huai neck Sigma and Dang Stuart power PA Kang sang Yong slightly timid carbonyl Po Dang traction Wo hook, and the Shanghai index wantonly alpha, is alpha - salt and shops Bi Mo School CuO Bi mo school and the Shanghai index B Phi wantonly alpha, is alpha - salt and shops chance step on fertilizer Dang Bi 's um gamma irresolute lacewing gun for example, Huan Pao disaster Liao palm feeding wantonly bite wantonly emperor Hui Kanshan forbiddance of alpha atomic force and the strong nuclear force and the electromagnetic force, the weak nuclear force, atom is a gravitational force and the strong nuclear force and the electromagnetic force, the weak nuclear force against each other balance, in the absence of interference environment, the balance can be maintained 1033 years above. We know that the conservation of energy, when the universe into the black hole universe original the strong nuclear force, electromagnetic force, the weak nuclear force, have to unify gravity. That is to say the total energy of gravitons in the universe is the total energy of the universe. How can gravity be as small as it used to be. Gravitation is the most powerful existence of the universe.。
2023年中科院考博细胞生物学历年名词解释及答案
1、周期细胞：细胞周期（cell cycle）是指细胞从一次分裂完毕开始到下一次分裂结束所经历的全过程，分为间期与分裂期两个阶段。
2、PCR技术：聚合酶链式反映，是体外酶促合成特异DNA片段的一种方法,由高温变性、低温退火及适温延伸等几步反映组成一个周期,循环进行,使目的DNA得以迅速扩增3、MPF：有丝分裂促进因子，由周期蛋白和蛋白激酶组成的复合物，启动细胞进入M期4、通讯连接：communication junction一种特殊的细胞连接方式，位于特化的具有细胞间通讯作用的细胞。
它除了有机械的细胞连接作用之外，还可以在细胞间形成电偶联或代谢偶联, 以此来传递信息。
5、细胞分化：cell differentiation，细胞的后代在结构和机能上发生差异，形成不同细胞的过程。
分化细胞获得并保持特化特性，合成转移性蛋白。
6、溶酶体：lysosome，真核细胞细胞质中由膜包围成的泡状细胞器，具有可消化生物体内各种有机物的多种酸性水解酶。
7、信号肽：signal peptide，分泌蛋白合成时在信号密码子指导下一方面合成的一段氨基酸顺序，有引导多肽链穿过内质网膜的作用。
8、整合素：Integrin，又称整联蛋白，一个异二聚体穿膜蛋白家族，起黏合受体的作用，促进细胞—基质和细胞—细胞黏合。
9、基因组：genome,一种生物的基本染色体套中所携带的所有基因，即单倍体中所含的所有基因。
在原核生物中既是一个连锁群中所含的所有遗传信息。
10、巨大染色体：giant chromosome，某些生物的细胞中，特别是在发育的某些阶段，可以观测到一些特殊的染色体, 它们的特点是体积巨大，细胞核和整个细胞体积也大，所以称为巨大染色体，涉及多线染色体和灯刷染色体。
1、奢侈基因：奢侈基因(Luxury gene)：即组织特异性基因（tissue-specific genes），是指不同类型细胞中特异性表达的基因，其产物赋予各种类型细胞特异的形态结构特性与功能2、MAPK 信号通路: MAPK,丝裂原活化蛋白激酶（mitogen-activated protein kinases，MAPKs）是细胞内的一类丝氨酸／苏氨酸蛋白激酶。
高三英语生物结构单选题50题
高三英语生物结构单选题50题1.The nucleus of a plant cell is responsible for_____.A.storing waterB.controlling cell activitiesC.producing energyD.breaking down waste答案：B。
本题考查植物细胞中细胞核的功能。
选项A，储存水是液泡的功能；选项C，产生能量主要是线粒体的功能；选项D，分解废物不是细胞核的主要功能。
而细胞核控制细胞的活动。
2.In animal cells, the organelle that is involved in packaging and transporting proteins is_____.A.lysosomeB.endoplasmic reticulumC.Golgi apparatusD.mitochondrion答案：C。
动物细胞中，高尔基体负责包装和运输蛋白质。
选项A，溶酶体主要是分解废物；选项B，内质网参与蛋白质的合成等；选项D，线粒体产生能量。
3.Which of the following is NOT a part of the cell membrane structure?A.PhospholipidsB.ProteinsC.CarbohydratesD.Nucleic acids答案：D。
细胞膜的结构主要由磷脂、蛋白质和少量的糖类组成。
核酸不是细胞膜的组成部分。
4.The cell wall of a plant cell is mainly made up of_____.A.celluloseB.proteinC.lipidD.starch答案：A。
植物细胞的细胞壁主要由纤维素组成。
选项B，蛋白质不是细胞壁的主要成分；选项C，脂质不是细胞壁的成分；选项D，淀粉主要存在于细胞内储存能量。
5.The organelle that is known as the “powerhouse” of the cell is_____.A.nucleusB.chloroplastC.mitochondrionD.endoplasmic reticulum答案：C。
Dispersion relations at finite temperature and density for nucleons and pions
a rXiv:h ep-ph/9911451v123Nov1999FIUN-CP-99/2Dispersion relations at finite temperature and density for nucleons and pions R.Hurtado 1Department of Physics,University of Wales Singleton Park,Swansea,SA28PP,United Kingdom J.Morales 1and C.Quimbay 1Departamento de F´ısica,Universidad Nacional de Colombia Ciudad Universitaria,Santaf´e de Bogot´a ,D.C.,Colombia November 21,1999To be published in Heavy Ion Physics Abstract We calculate the nucleonic and pionic dispersion relations at finite tem-perature (T )and non-vanishing chemical potentials (µf )in the context of an effective chiral theory that describes the strong and electromagnetic interac-tions for nucleons and pions.The dispersion relations are calculated in thebroken chiral symmetry phase,where the nucleons are massive and pions are taken as massless.The calculation is performed at lowest order in the energy expansion,working in the framework of the real time formalism of thermal field theory in the Feynman gauge.These one-loop dispersion relations are ob-tained at leading order with respect to T and µf .We also evaluate the effective masses of the quasi-nucleon and quasi-pion excitations in thermal and chemical conditions as the ones of a neutron star.Keywords:Chiral Lagrangians,Dispersion Relations,Finite Temperature,Chemical Potentials,Nucleons,Pions.1IntroductionEffective chiral theories have become a major conceptual and analytical tool in par-ticle physics driven by the need of a theory to describe the low–energy phenomenology of QCD.The foundations were formulated originally by Weinberg[1]to characterise the most general S-matrix elements for soft pion interactions and later it was further developed by Gasser and Leutwyler[2].Effective chiral theories have shown to be an adequate framework to treat low–energy phenomenology[3]-[6],as they reproduce,at lowest order in the chiral expansion,the most important results from current algebras including the low–energy theorems,and at next-to-leading order,they give precise corrections to these results[3].They have been widely applied to different problems as meson–meson,meson–baryon,photon–photon,photon–meson and photon–baryon scattering,photoproduction processes and rare kaon decays[7,18].The propagation properties of relativistic particles in plasmas atfinite tempera-ture is also a subject of increasing interest.It is well known that the interaction of a particle with a plasma in thermal equilibrium at temperature T modifies the Disper-sion Relations(DR)with respect to the zero temperature situation.This phenomenon has been extensively investigated for the non-dense plasma case[19]-[30],i.e.when the chemical potential(µf)associated to the fermions of the thermal plasma is equal to zero:µf=0and T=0.In this case the Fermionic Dispersion Relations(FDR) have been studied for massless fermions in[19]-[22]and massive fermions in[23]-[30]. The FDR describe the propagation of the fermionic excitations of the plasma(quasi-fermions and quasi-holes)through the thermal background.These excitations are originated in the collective behaviour of the plasma system at low momentum.On the other hand,DR describing the propagation of the fermionic excitations of a dense plasma atfinite temperature can be found in literature[31]-[35].For the dense plasma case atfinite temperature,i.e.µf=0and T=0,the FDR have been calculated both for massless fermions in[31]-[34]and for massive fermions in[35]. These FDR have been calculated in the context of realistic physical models,as for instance,the Minimal Standard Model[29,34].In the present work we calculate the DR for quasi–nucleons and quasi–pions prop-agating in a plasma atfinite temperature and non–vanishing chemical potentials. The calculation is performed for a SU(2)L×SU(2)R effective chiral Lagrangian with the chiral symmetry broken into SU(2)L+R.This Lagrangian,which we introduce in section2,describe the strong and electromagnetic interactions of massive nucleons and massless pions.The calculation is performed using the real time formalism of the thermalfield theory[36]-[38]in the Feynman gauge.The one–loop DR are calculated at lowest order in the energy expansion and obtained taking the T2andµ2f terms from the self–energy,as shown in section3.As an application of the DR obtained,we evaluate the effective masses of the quasi–nucleon and quasi–pion excitations takingthe following values:T=150MeV,µp=100MeV andµn=2µp,beingµp(µn)the chemical potential for protons(neutrons)[43].This evaluation is shown in section4, as well as the discussion of the main results and conclusions.2Effective chiral Lagrangian at leading order in the energy expansionEffective chiral theories are founded in the existence of an energy scaleΛχat which chiral symmetry SU(N f)L×SU(N f)R,with N f the number offlavours,breaks into SU(N f)L+R leading to N2f−1Goldstone bosons associated to the N f broken generators.These Goldstone bosons are identified with the meson ground state octet for N f=3,and with the triplet of pions[2,6]in the case of N f=2.The chiral symmetry of the Lagrangian is broken through the introduction of an explicit mass term for the nucleons.A general form for a Lagrangian with SU(2)L+R symmetry describing the strong and electromagnetic interactions for massive nucleons and massless pions is[39,40]:L=F2π4FµνFµν,(2.1)whereLπN=¯Niγµ∂µN−ie¯NγµAµ 1+τ32FπN+Mg2A¯N τ·πFπ,(2.4) where the covariant derivative and electromagnetic charge are defined asDµΣ=∂µΣ+ieAµ[Q,Σ],(2.5)Q= 23 .(2.6)Hereπ,N and Aµrepresent the pion,nucleon and electromagneticfields,Fπ=93MeV is the pion decay constant,e is the electromagnetic coupling constant,g A=1.26is the axial coupling constant,and M is the average nucleon mass.3Dispersion relations for nucleons and pionsIn this section we calculate the DR for nucleons and pions in the framework of the Lagrangian given by(2.1).We consider the propagation of the nucleonic and pionic excitations in a dense thermal plasma constituted by protons,neutrons,charged pions,=0,where f i neutral pions and photons,being this plasma characterised byµfirepresents the different fermion species.The calculation is performed in the real time formalism of the thermalfield theory in the Feynman gauge.The real part of the nucleonic and pionic self-energies are evaluated at lowest order in the energy expansion and at one-loop order(g A/Fπ)2,considering only the leading contributions in T andµf.The Feynman rules for the vertices atfinite temperature and density(Fig.1)are the same as those at T=0andµf=0,while the propagators in the Feynman gauge for photons Dµν(p),pions D(p)and massive nucleons S(p)are[41]:Dµν(p)=−gµν 1−iΓb(p),(3.2)p2+iǫp/S(p)=,(3.6)e(p·u)/T−1n f(p)=θ(p·u)n−f(p)+θ(−p·u)n+f(p),(3.7) being n b(p)the Bose–Einstein distribution function,and the Fermi–Dirac distribution functions for fermions(n−f(p))and anti-fermions(n+f(p))are:1n∓f(p)=3.1Nucleonic Dispersion RelationUsing the Feynman diagrams given in Fig.(2),we calculate the FDR for quasi–protons and quasi–neutrons.In order to apply a similar procedure to that followed in[21,29,34],wefirst consider the hypothetical case of massless nucleons.In this case,we obtain two solutions:one describing the propagation of quasi-fermionsw(k)=M p,n+k3M p,n+O(k3),(3.9)and another one describing the propagation of quasi-holesw(k)=M p,n−k3M p,n+O(k3).(3.10)We observe that if k=0,w(k)=M p,n.Then M p(M n)can be interpreted as the effective mass of the quasi-protons(quasi-neutrons),and their expressions are: M2p= 3g2A M28 T2+g2A M22 +e2µ2p64F2πT2+g2A M22+µ2p .(3.12)For the limit k>>M p,n the FDR are:w(k)=k+M2p,n2k3Log(2k2of the chiral phase transition in non–zero hadronic density [42].We observe that m p,n>Mp,n ,where m p (m n )is the rest mass of the proton (neutron)and M p,n aregiven by (3.11)and (3.12).In the limit m 2p,n >>M 2p,n the FDR become [24]:w (k )2=k 2+m 2p,n +M 2p,n .(3.15)Starting from relation (3.15)and equations (3.11),(3.12),we obtain a generalexpression for the nucleon effective mass splitting ∆M 2N :∆M 2N =m 2p −m 2n +e 2T 28π2 g 2A M 2µ2n 8F 2π+e 2µ2p .(3.16)3.2Pionic Dispersion RelationUsing the Feynman rules given in Fig.(1),we obtain the following DR for quasi-pions:w (k )2=k 2+M 2π±,π0,(3.17)where M π±(M π0)is the effective mass for charged (neutral)quasi–pions,and their expressions are:M 2π±=T 2F 2π+e2 +g 2A M 28π2F 2π2π2T 212.(3.20)4Results and conclusionsWe now give the results of the calculation for the effective masses of quasi–nucleons and quasi–pions.We have used the following values m p =938.271MeV,m n =939.566MeV,M =938.919MeV,T =150MeV,µp =100MeV,µn =200MeV,e 2=0.095.The temperature and chemical potential values are of the order of those in a neutron star [43].The results for the effective masses are:M p=1036.5133MeV M n=1033.8394MeV M π±=637.2312MeV M π0=637.0914MeVwhere M p,M n,Mπ±and Mπ0are the effective masses for the proton,neutron,charged pions and the neutral pion,including the strong and electromagnetic interactions.The effective mass splitting for nucleons and pions are:∆(M p−M n)=2.6740MeV∆(Mπ±−Mπ0)=0.1398MeVwhere∆(Mπ±−Mπ0)is due exclusively to the combined electromagnetic interaction and temperature effects,as shown at(3.20).For the nucleons,from the total effective mass splitting∆(M p−M n),the combined electromagnetic and temperature contribute is∆em(M p−M n)=0.0058MeV.In conclusion,temperature effects enter into the effective mass splitting relations (3.16)and(3.20)exclusively in the electromagnetic interaction term,which at T=0vanishes.Also,in the framework of our model we found that,for the chemical potentials and temperature used,the effective mass on the proton is bigger than the one of the neutron.Our results should be improved by considering massive pions and introducing the weak interaction,as well as using a realistic model for neutron stars, to be presented in short.AcknowledgementsThis work was supported by COLCIENCIAS(Colombia),Universidad Nacional de Colombia and Centro Internacional de F´ısica.We want also to thank to Fernando Cristancho by invitation to participate in the Third Latinamerican Workshop on Nuclear and Heavy Ion Physics,San Andr´e s,Colombia.References[1]Weinberg,Physica A96(1979)327.[2]J.Gasser and Leutwyler,Ann.Phys(N.Y)(1984)158;Nucl.Phys.B250(1985)465.[3]J.F.Donoghue,E.Golowich and B.R.Holstein,“Dynamics of the StandardModel”,Cambridge University Press,1992.[4]U.G.Meissner,Rep.Prog.Phys.56(1993)903.[5]A.Pich,Rep.Prog.Phys.58(1995)563.[6]G.Ecker,Prog.Part.Nucl.Phys.35(1995)1;G.Ecker and M.Mojzis,Phys.Lett.B365(1996)312.[7]M.Wise,Phys.Rev.D45(1992)R2188.[8]G.Bardman and J.Donoghue,Phys.Lett.B280(1992)287.[9]T.M.Yan,H.Y.Chang and 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al.,Phys.Rev.Lett.48(1982)1140;J.Polonyi et al.,Phys.Rev.Lett.53(1984), 664.[43]J.Byrne,”Neutrons,Nuclei and Matter and Exploration of the Physics of SlowNeutrons”,Institute of Physics Publishing,Bristol and Philadelphia,1996.Figure1:Feynman Rules of the LπN.Figure2:Self–energy contributions for the calculation of FDR for:(a)Protons(b) Neutrons.。
Dropping Sigma-Meson Mass and In-Medium S-Wave pion-pion Correlations
a r X i v :n u c l -t h /990876v 2 31 A u g 1999Dropping σ-Meson Mass and In-Medium S-wave π-πCorrelationsZ.Aouissat 1,G.Chanfray 2,P.Schuck 3,J.Wambach 11IKP,Technische Universit¨a t Darmstadt,Schloßgartenstraße 9,64289Darmstadt,Germany.2IPN Lyon.43Bd.du 11Novembre 1918,F69622Villeurbanne C´e dex,France.3ISN,Universite Joseph Fourier,CNRS-IN2P3,53avenue des Martyrs,F-38026Grenoble C´e dex,France.(February 9,2008)The influence of a dropping σ-meson mass on previously calculated in-medium ππcorrelations in the J =I =0(σ-meson)channel [2,?]is investigated.It is found that the invariant-mass distribution around the vacuum threshold experiences a further strong enhancement with respect to standard many-body effects.The relevance of this result for the explanation of recent A (π,2π)X data is pointed out.In medium s-wave pion-pion correlations have recently attracted much attention both on the theoretical [1–7]and experimental [8]sides.These studies are of rele-vance for the behavior of the in-medium chiral conden-sate and its fluctuations with increasing density [7].In earlier studies we have shown that standard p-wave cou-pling of the pion to ∆-h and p-h configurations induces a strong enhancement of the ππinvariant-mass distri-bution around the 2m πthreshold [2,3],thus signalling increased fluctuations in the σ-channel.This fact was in-dependently confirmed in [5].It has been argued in [2,4]that this effect could possibly explain the A (π,2π)knock-out reaction data from the CHAOS collaboration [8].More recently Vicente Vacas and Oset [6]have claimed that the theory underestimates the experimentally found π−πmass enhancement.This claim may be partly ques-tioned,since the reaction theory calls for a calculation with a finite total three momentum of the in-medium pion pairs ∗.On the other hand Hatsuda et al.[7]ar-gued that the partial restoration of chiral symmetry in nuclear matter,which leads to a dropping of the σ-meson mass [10],induces similar effects as the standard many-body correlation mentioned above.It is therefore natural to study the combination of both effects.This is the ob-jective of the present note.As a model for ππscattering we consider the lin-ear sigma model treated in leading order of the 1/N -expansion [9].The scattering matrix can then be cast in the following formT ab,cd (s )=δab δcdD −1π(s )−D −1σ(s )D π(s ),(1)where s is the Mandelstam variable.In Eq.(1)D π(s )s −m 2π,f π=√1−λ2Σππ(s )−1,(3)where Σππ(s )is the ππself-energy regularized by meansof a form factor which is used as a fit function [2]and allows to reproduce the experimental ππphase shifts.The coupling constant λ2denotes the bare quartic cou-pling of the linear σ-model,related to the mean-field pion mass m π,sigma mass m σ,and the condensate σ via the mean-field saturated Ward identitym 2σ=m 2π+2λ2 σ 2.(4)It is clear from what was said above that the σ-mesonpropagator in this approach is correctly defined,since it satisfies a whole hierarchy of Ward identities.In cold nuclear matter the pion is dominantly coupled to ∆-h,p-h,as well as to the 2p-2h excitations which,on the other hand,are renormalized by means of re-pulsive nuclear short-range correlations,(see [3]for de-tails).Since the pion is a (near)Goldstone mode,its in-medium s-wave renormalization does not induce con-siderable changes.The sigma meson,on the other hand,is not protected against an important s-wave renormal-ization from chiral symmetry.Therefore,following a very economical procedure,we extract an approximate density 1dependence of the mean-field sigma meson mass by tak-ing into account the density dependence of the conden-sate.From eq.(4)it is clear that the density dependence of the sigma-meson is essentially dictated by the density dependence of the condensate.FIG.1.Results for the imaginary part of the in-medium sigma-meson propagator.Except for the vacuum case(full line curve)the remaining in-medium curves are computed at normal nuclear matter density.The dashed-dotted curve is forα=0,dashed forα=0.2and the dotted forα=0.3. For densities below and around nuclear saturation den-sityρ0we take for the in-medium sigma-meson mass the simple ansatz(see also[7])ρmσ(ρ)=mσ(1−α[1]P.Schuck,W.N¨o renberg,G.Chanfray,Z.Phys.A330(1988)119.[2]P.Schuck,Z.Aouissat,F.Bonutti,G.Chanfray,E.Fra-giacomo,N.Grion,J.Wambach,Proceedings of the XXXVI,international Winter Meetingon Nuclear Physics,Ed.I.Iori,Bormio(Italy),January1998;nucl-th/9806069.[3]Z.Aouissat,R.Rapp,G.Chanfray,P.Schuck,J.Wambach,Nucl.Phys.A581(1995)471.[4]R.Rapp,J.W.Durso,Z.Aouissat,G.Chanfray,O.Krehl,P.Schuck,J.Speth,J.Wambach,Phys.Rev.C59(1999)R1237.[5]H.C.Chiang,E.Oset,M.J.Vicente Vacas,Nucl.Phys.A644(1998)77.[6]M.J.Vicente Vacas,E.Oset,nucl-th/9907008[7]T.Hatsuda,T.Kunihiro,H.Shimizu,Phys.Rev.Lett.82(1999)2840.[8]F.Bonutti et al.,Phys.Rev.Lett.77(1996)603.[9]Z.Aouissat,P.Schuck,J.Wambach,Nucl.Phys.A.618(1997)402.[10]G.E.Brown,M.Rho,Phys.Rep.269(1996)333.[11]D.Davesne,Y.J.Zhang,G.Chanfray,to be published.[12]Z.Aouissat,Ph.D.Thesis Report,ISN93-63,Grenoble.3。
Phosphatidylinositol 4-Kinase Type II{alpha} Cellugyrin-Positive Glucose Transporter 4 Vesicles
Phosphatidylinositol 4-Kinase Type II ␣Is Targeted Specifically to Cellugyrin-Positive Glucose Transporter 4VesiclesZhao Xu,Guanrong Huang,and Konstantin V.KandrorBoston University School of Medicine,Boston,Massachusetts 02118Phosphoinositides now emerge as important reg-ulators of membrane traffic.In particular,phos-phatidylinositol 4-phosphate may serve as a pre-cursor for polyphosphorylated derivatives of phosphatidylinositol and,also,may regulate vesic-ular traffic by recruiting specific proteins to the membrane.Early results have demonstrated the presence of phosphatidylinositol 4-kinase (PI4K)activity in glucose transporter 4(Glut4)vesicles from fat and skeletal muscle cells.However,the molecular identity of phosphatidylinositol 4-ki-nase(s)associated with Glut4vesicles has not been characterized.It has also been determined that Glut4vesicles are not homogeneous and rep-resent a mixture of at least two vesicular popula-tions:ubiquitous cellugyrin-positive transport ves-icles and specialized cellugyrin-negative insulin-responsive Glut4storage vesicles,which are different in size,protein composition,and func-tional ing sequential immunoadsorp-tion,subcellular fractionation,and immunofluores-cence staining,we show that virtually all PI4K activity in Glut4vesicles is represented by PI4K type II ␣,which is associated with cellugyrin-posi-tive vesicles and is not detectable in the Glut4storage vesicles.The unique N terminus of PI4K type II ␣is required for the targeting of the enzyme to cellugyrin-positive vesicles.Knockdown of PI4K type II ␣with the help of short hairpin RNA does not decrease the amount of cellugyrin-positive vesi-cles in human embryonic kidney 293cells.(Molec-ular Endocrinology 20:2890–2897,2006)INSULIN STIMULATES GLUCOSE uptake in fat and skeletal muscle cells by promoting fusion of intra-cellular glucose transporter 4(Glut4)-storage vesicles (GSVs)with the plasma membrane.In basal fat cells,insulin-responsive GSVs compartmentalize 50–80%of the total Glut4pool with the rest of the transporter being present in endosomes,trans-Golgi network,and in nonspecialized intracellular transport vesicles (1).The mechanisms that control the distribution of Glut4among different intracellular compartments are cur-rently unknown.It is believed,however,that phosphoi-nositides and phosphoinositide kinases play a key role in the regulation of membrane traffic (2,3).In partic-ular,phosphatidylinositol 4-phosphate (PI4P),which has been considered mainly as a precursor for polyphosphorylated derivatives of phosphatidylinosi-tol,is now emerging as an important regulator of in-tracellular trafficking in its own right (4–6).Early results have demonstrated the presence of phosphatidylinositol 4-kinase (PI4K)in Glut4vesicles from fat (7)and skeletal muscle (8)cells.However,Glut4vesicles are not homogeneous and represent a mixture of at least two vesicular populations.These vesicular populations are different in size,protein composition,and functional properties (9,10).A con-venient marker,which is specifically present in only one vesicular population,is cellugyrin,a four trans-membrane protein representing a ubiquitous analog of the major synaptic vesicle protein,synaptogyrin (11,12).Cellugyrin-negative Glut4vesicles,or GSVs,are enriched in Glut4and insulin-regulated aminopepti-dase and are translocated to the plasma membrane in response to insulin stimulation.Cellugyrin-positive vesicles are not enriched in Glut4or insulin-regulated aminopeptidase,are not translocated to the plasma membrane,and may thus represent intracellular trans-port vesicles en route to GSVs.In agreement with this idea,further analysis has suggested that cellugyrin-positive vesicles represent ubiquitous intracellular transport vesicles present in all cell types tested (13).Because immunoadsorption with anti-Glut4antibod-ies (7,8)results in the isolation of both vesicular pop-ulations,it is not clear which compartment contains PI4K activity.The molecular identity of PI4K associated with Glut4vesicles has not been characterized either.At present,four different PI4Ks have been cloned in mammalian cells:PI4K type II (PI4KII)␣and and PI4K type III ␣and (14).These enzymes are distinguished by dif-First Published Online June 13,2006Abbreviations: a.a.,Amino acids;AP,adaptor protein;EGFP,enhanced green fluorescent protein;Glut4,glucose transporter 4;GSV,Glut4storage vesicle;HEK,human em-bryonic kidney;HM,heavy microsome;LM,light microsome;PI4K,phosphatidylinositol 4-kinase;PI4KII,type II PI4K;PI4P,phosphatidylinositol 4-phosphate;PM,plasma mem-brane;PNS,postnuclear supernatant;SDS,sodium dodecyl sulfate;shRNA,short hairpin RNA;UB,unbound material.Molecular Endocrinology is published monthly by The Endocrine Society (),the foremost professional society serving the endocrine community.0888-8809/06/$15.00/0Molecular Endocrinology 20(11):2890–2897Printed in U.S.A.Copyright ©2006by The Endocrine Societydoi:10.1210/me.2006-01932890ferences in their enzymatic properties and by sensitiv-ity to inhibitors.In particular,both type II kinases are resistant to wortmannin and are inhibited by adeno-sine,whereas both type III kinases are resistant to adenosine and sensitive to wortmannin(15).Here,we report that PI4KII␣is responsible for most of the PI4K activity associated with Glut4vesicles. Virtually all this activity is associated with cellugyrin-positive vesicles and is not detectable in the GSVs.We have also determined that the unique N terminus of the enzyme is required for targeting of PI4KII␣to cellu-gyrin-positive vesicles.Knockdown of PI4KII␣with the help of short hairpin RNA(shRNA)does not affect the sedimentational distribution of cellugyrin-positive ves-icles,suggesting that the biogenesis of the latter com-partment does not involve PI4KII␣.RESULTS3T3-L1adipocytes were homogenized and fraction-ated by centrifugation at16,000ϫg into the pellet and the supernatant.Small membrane vesicles(including both cellugyrin-positive vesicles and cellugyrin-nega-tive GSVs)recovered in the supernatant of this cen-trifugation were purified further by immunoadsorption with1F8or with anticellugyrin beads(Fig.1A).Material retained on the beads was subsequently eluted with 1%Triton X-100and,then,with sodium dodecyl sul-fate(SDS)-containing Laemmli sample buffer(16). Note,that Triton solubilizes all the vesicular proteins with the exception of those that directly interact withimmobilized antibodies.The latter proteins are eluted only with SDS-containing buffers,such as Laemmli sample buffer.Immunoadsorption with1F8beads re-sults in the isolation of virtually all Glut4-containing vesicles.After immunoadsorption with anticellugyrin beads,some Glut4vesicles stay in the postadsorptive supernatant[unbound material(UB)],indicating that a population of Glut4vesicles does not contain cellu-gyrin.PI4K activity and PI4KII␣were present in the eluates from both1F8and anticellugyrin beads(Fig.1, A and B),whereas PI4KIIwas not detectable in either fraction(data not shown).To specifically isolate cellugyrin-negative GSVs,we first removed cellugyrin-positive Glut4-vesicles by im-munoadsorption with anticellugyrin beads,collected the postadsorptive supernatant(UB)and immunoiso-lated cellugyrin-negative Glut4vesicles from this ma-terial using1F8beads.Figure2shows that PI4KII␣is present in cellugyrin-positive vesicles and is absent from cellugyrin-negative Glut4vesicles.PI4KIIis not associated with either compartment.To confirm this result,we separated cellugyrin-neg-ative and cellugyrin-positive vesicles by centrifugation in a sucrose gradient,because cellugyrin-negative GSVs have a higher sedimentation coefficient than cellugyrin-positive vesicles.Figure3demonstrates that,upon sucrose gradient centrifugation,the peak of PI4KII␣-containing vesicles overlaps with the peak of cellugyrin-containing vesicles and not with the peak of cellugyrin-negative GSVs.PI4KIIis present either in the cytosol in a free form or is associated with rapidly sedimenting membranes(see below)and,in agree-ment with previously shown data,is not present in either cellugyrin-positive or-negative Glut4vesicles. Fig.1.PI4KII␣and PI4K Activity Are Present in the Total Fraction of Glut4-Containing Vesicles and in Cellugyrin(Cg)-Containing Vesicles3T3-L1adipocytes were homogenized in PBS and sub-jected to centrifugation at16,000ϫg for20min.The result-ing supernatant(600g in200l)was incubated with1F8 beads,anticellugyrin beads(Cg beads),and nonspecific IgG beads overnight.Unbound material was collected,and the beads were washed and subsequently eluted with100l of 1%Triton X-100in PBS and then with100l of nonreducing Laemmli sample buffer.A,UB(30l),Triton X-100eluate(TX, 50l),and SDS eluate(SDS,50l)were analyzed by Western blotting.B,PI4K activity was measured in Triton X-100elu-ates.Fig.2.PI4KII␣Is Specifically Associated with Cellugyrin (Cg)-Positive Vesicles and Is Absent from Cellugyrin-Nega-tive GSVsImmunoadsorption was sequentially performed with anti-cellugyrin beads and then with1F8beads as described in the legend to Fig.1.UB,Triton X-100eluate(TX),and SDS eluate (SDS)were analyzed by Western blotting.Nonspecific signal from the IgG heavy chain in SDS eluate is boxed.Xu et al.•PI4KII␣in Cellugyrin-Positive Vesicles Mol Endocrinol,November2006,20(11):2890–28972891With the help of double immunofluorescence stain-ing,we found that the intracellular distribution of PI4KII ␣significantly overlaps with that of cellugyrin (Fig.4).In addition,neither PI4KII ␣nor total PI4K ac-tivity is translocated to the plasma membrane in re-sponse to insulin stimulation (Fig.5;see also Ref.7).This result also supports the notion that PI4KII ␣is present not in insulin-responsive GSVs,but rather in cellugyrin-positive Glut4vesicles that maintain intra-cellular localization both in the absence and in the presence of insulin (9,10).Finally,we found that the expression levels of PI4KII ␣in differentiating 3T3-L1cells are stable,which is more consistent with the expression pattern of cellugyrin,rather than Glut4(Fig.6).Thus,we found that PI4KII ␣is virtually undetectable in cellugyrin-negative GSVs but is considerably en-riched in cellugyrin-positive population of Glut4-vesi-cles.To determine whether or not type III PI4K can contribute to the total PI4K activity in this compart-ment,we measured this activity in the presence of wortmannin and adenosine.In an agreement with pre-viously published results (7,8),we found that PI4Kactivity in cellugyrin-positive vesicles is resistant to wortmannin and is virtually completely inhibited by adenosine (Fig.7).In parallel experiments,we deter-mined that wortmannin completely inhibited insulin-activated glucose transport and Glut4translocation in 3T3-L1adipocytes (data not shown).Taken together,these results suggest that PI4KII ␣is the major or the only PI4K in this compartment.We believe that cellugyrin-positive vesicles repre-sent the first biochemically homogeneous membrane compartment that specifically contains PI4KII ␣and not a closely related isoform,PI4KII .This raises the question of what is the nature of the targeting signal that is responsible for the presence of PI4KII ␣in these vesicles.Interestingly,a recent report shows that PI4KII ␣is also associated with synaptic vesicles in the brain (17),a compartment that may be evolutionarily related to ubiquitous cellugyrin-containing vesicles (see Discussion ).However,because PI4KII is unde-tectable in neurons (17),it remains unclear whether PI4KII ␣is targeted to synaptic vesicles by a specific sequence or is present there simply by virtue of being the only isoform of PI4K expressed in this cell type.To study targeting of PI4KII ␣and PI4KII ,we tran-siently expressed these enzymes in human embryonic kidney (HEK)293cells.Cells were homogenized and centrifuged at 27,000ϫg to separate the fraction of small vesicles from heavy membranes.The superna-tant of the 27,000ϫg centrifugation was further frac-tionated in a linear sucrose velocity gradient.Figure 8,A and B,shows that PI4KII ␣is targeted to cellugyrin-positive vesicles,whereas all PI4KII in the 27,000ϫg supernatant cosediments with free soluble proteins.This result strongly suggests that localization of PI4KII ␣in cellugyrin-positive vesicles requires a spe-cific targeting sequence.A significant fraction of both PI4KII ␣and PI4KII is recovered in the pellet of the 27,000ϫg centrifugation (Fig.8G),indicating that these enzymes are also associated with heavy mem-brane structures,such as endosomes and/or Golgi apparatus (18,19).PI4KII ␣and PI4KII demonstrate a high degree of similarity with most of the differences localized in the N termini of the enzymes (18,20).We have created four mutants of PI4KII ␣with the truncated N terminus [amino acids (a.a.)94–479,104–479,125–479,and 147–479]and expressed them in HEK 293cells.As is shown in Fig.8,C–F,truncation of the N terminus leads to a gradual decrease in the efficiency of target-ing of PI4KII ␣to cellugyrin-positive vesicles,so that the last mutant (a.a.147–479)is distributed to the fraction of free soluble proteins similar to PI4KII .Be-cause all these mutants are present in the pellet of the 27,000ϫg centrifugation (Fig.8G),we believe that their general membrane targeting [mediated by palmi-toylation of a cystein-rich motif in the middle of the protein (15)]is intact,and that the N terminus of PI4KII ␣may specifically be required for targeting of the enzyme to small cellugyrin-positivevesicles.Fig.3.The Peak of PI4KII ␣Colocalizes with the Peak of Cellugyrin (Cg)-Positive Vesicles upon Sucrose Gradient Centrifugation3T3-L1adipocytes were homogenized in PBS and centri-fuged at 16,000ϫg for 20min.The resulting supernatant (400g)was fractionated in a 10–30%continuous sucrose gradient for 55min at 48,000rpm in a Beckman SW-55rotor at 4C.The gradient was separated into 23fractions,which were analyzed by Western blotting.Pel.,Pellet.Fig.4.Colocalization of PI4KII ␣with Cellugyrin3T3-L1adipocytes stably expressing cellugyrin-EGFP were serum starved in DMEM for 2h,fixed with 4%parafor-maldehyde,permeabilized with 0.2%Triton X-100,and im-munostained with a polyclonal primary antibody against PI4KII ␣and a Cy3-labeled secondary antibody.Staining with nonspecific IgG and the same secondary antibody did not produce any detectable signal and is not shown.2892Mol Endocrinol,November 2006,20(11):2890–2897Xu et al .•PI4KII ␣in Cellugyrin-Positive VesiclesThe presence of PI4KII␣in cellugyrin-positive vesi-cles suggests that this enzyme may be involved in the biogenesis of this compartment.To test this hypoth-esis,we have knocked down PI4KII␣in HEK293cells using the RNA interference approach(5).We were able to achieve a significant decrease in the total levels of PI4KII␣(Fig.9A).In particular,the presence of the enzyme in cellugyrin-positive vesicles becomes virtu-ally undetectable(Fig.9B).This,however,does not have any effect on the sedimentational distribution of cellugyrin,suggesting that PI4KII␣may not be in-volved in the formation or trafficking of cellugyrin-positive vesicles.DISCUSSIONPrevious studies with overexpressed tagged proteins have demonstrated that PI4KII␣and PI4KIIhave overlapping but still distinct intracellular localization, although the biochemical nature of the PI4KII-contain-ing compartments is still a matter of debate(18,19). Here,we studied the intracellular localization of en-dogenous enzymes using predominantly a biochemi-cal approach and identified an individual membrane compartment(called cellugyrin-positive transport ves-icles)that specifically contains PI4KII␣but not other isoforms of PI4K.This suggests that different isoforms of the enzyme play nonredundant functions in the cell. We show,furthermore,that targeting of PI4KII␣to cellugyrin-positive vesicles requires the unique N ter-minus of the enzyme.What is the biological nature of cellugyrin-positive vesicles?Originally,this compartment was identified as a subpopulation of Glut4vesicles(9).However, based on the protein composition of cellugyrin vesi-cles and their intracellular localization and rapid accu-mulation of recycling proteins,we have suggested that cellugyrin-containing vesicles may mediate protein transport from sorting endosomes to the endocytic recycling compartment and/or to trans-Golgi network and may thus represent a ubiquitous type of an intra-cellular vesicular carrier(9,10).Indeed,further analysis has demonstrated that uniform cellugyrin-containing vesicles are present in all cell types studied(13).In-terestingly,overexpression of cellugyrin increases the number of vesicles,suggesting that this protein may play a key role in vesicle biogenesis(21).Fig.6.The Expression Level of PI4KII␣Remains Stable dur-ing Differentiation of3T3-L1Adipocytes3T3-L1preadipocytes were cultured and differentiated asdescribed in Materials and Methods.Cell extracts were pre-pared on each day of differentiation and analyzed by Westernblotting.Fig.7.PI4K Activity Associated with Cellugyrin-PositiveVesicles Is Inhibited by Adenosine,But Not by WortmanninA,Cellugyrin-positive vesicles were immunoisolated from3T3-L1adipocytes and subjected to PI4K assay as describedin Materials and Methods in the absence(Control)and in thepresence of500n M wortmannin(Wort)or200M adenosine(Adenosine).B,PI4K activity in cellugyrin-positive vesicleswas measured in the presence of different concentrations ofadenosine.Fig.5.Insulin Does Not Have a Major Effect on the Intracellular Localization of PI4KII␣3T3-L1adipocytes were incubated in serum-free DMEM for2h and treated with(ϩ)or without(Ϫ)100n M insulin for15min at37C.The insulin action was stopped by the addition of KCN,and fat cells were fractionated into PM,HM,and LM fractions as described in Materials and Methods.A,Each fraction(50g)was analyzed by Western blotting.B,PI4K activity was measured in PM and LM fractions(50g each).Xu et al.•PI4KII␣in Cellugyrin-Positive Vesicles Mol Endocrinol,November2006,20(11):2890–28972893An important concern with the in vitro analysis of small membrane compartments is that they may rep-resent an artificial product of large membrane struc-tures,such as endosomes,that may be fragmented into smaller vesicles upon cell homogenization.How-ever,at least two lines of evidence strongly suggest that cellugyrin-containing vesicles do not represent an artifact of cell homogenization,but exist in vivo .First,special control experiments demonstrate that homog-enization does not affect the yield and the size of these vesicles (10).Second,we have established an in vitro budding assay for cellugyrin-containing vesicles and demonstrated that these vesicles are formed in vitro from heavy membranes,presumably endosomes,in a cytosol-,ATP-,time-,and temperature-dependent fashion (22).Thus,because cellugyrin-containing ves-icles are present in extracts of nonhomogenized cells and are formed in vitro in a physiological process,we believe that these vesicles do not represent an artifact of homogenization,but exist in the living cell.Recently,Guo et al.(17)have found that PI4KII ␣is responsible for PI4K activity in synaptic vesicles.In-terestingly,there are several parallels between spe-cialized synaptic vesicles in neurons and ubiquitous cellugyrin-containing vesicles.In particular,these types of vesicles have identical sedimentation coeffi-cients (13)and contain secretory carrier membrane proteins,synapto/cellubrevin,and synapto/cellugyrin as their major component proteins.According to one hypothesis,synaptic vesicles may develop fromubiq-Fig.8.Targeting of PI4K ␣to Cellugyrin (Cg)-Positive Vesi-cles Requires the N Terminus of the EnzymeA–F,HEK 293cells were transiently transfected with myc-tagged wild-type PI4KII ␣,wild-type PI4KII ,and truncated mutants of PI4KII ␣.Cells were fractionated as described in Materials and Methods ,and the supernatant of the 27,000ϫg centrifugation (400g)was fractionated in a 10–30%con-tinuous sucrose gradient for 1.5h at 48,000rpm in a Beck-man SW-55rotor at 4C.The gradient was separated into23–25fractions,which were analyzed by Western blotting with a monoclonal antibody against the myc epitope and with a polyclonal antibody against cellugyrin.G,Total expression levels of the constructs in PNS and in the pellet of the 27,000ϫg centrifugation.Panels show Western blot with the anti-mycantibody.Fig.9.Knockdown of PI4K ␣Does Not Affect Cellugyrin (Cg)-Positive VesiclesPI4KII ␣in HEK 293cells was knocked down as described in Materials and Methods .A,Total cell lysate was analyzed by Western blotting.B,Supernatant of the 27,000ϫg centrifu-gation (400g)was fractionated in a 10–30%continuous sucrose gradient for 1.5h at 48,000rpm in a Beckman SW-55rotor at 4C.The gradient was separated into 23fractions,which were analyzed by Western blotting with polyclonal antibodies against PI4KII ␣and cellugyrin.EV,Empty vector.2894Mol Endocrinol,November 2006,20(11):2890–2897Xu et al .•PI4KII ␣in Cellugyrin-Positive Vesiclesuitous microvesicles in the process of neuronal differ-entiation by substitution of the ubiquitously expressed protein isoforms with their neuronal counterparts.In-deed,differentiating mouse brain at embryonic d16 does not yet express synaptic proteins and has only cellugyrin-containing microvesicles.With differentia-tion,expression of synaptic proteins,such as synap-tobrevin and synaptogyrin,is increased whereas ex-pression of cellubrevin and cellugyrin gradually terminates(Dr.J.K.Blusztajn,Boston University School of Medicine,personal communication)which may lead to transformation of ubiquitous transport vesicles into highly specialized synaptic vesicles.The fact that PI4KII␣is present in both types of vesicles suggests that it may be involved in some basic non-specialized aspects of the vesicular traffic.Knock-down experiments(Fig.9)demonstrate that the direct involvement of PI4KII␣in the biogenesis of this vesic-ular compartment is unlikely.One hypothesis is that PI4KII␣may use small vesicular carriers as vessels to move from one subcellular compartment to another, i.e.from the plasma membrane to sorting endosomes or from sorting endosomes to recycling endosomes and/or trans-Golgi network.This may give the cell an opportunity to balance the endocytic and the exocytic PI4P-dependent membrane flow.Recently,Salazar et al.(23)showed that PI4KII␣represented a component of AP3-derived vesicles. Although this result does not exclude a possibility that PI4KII␣may be present in other vesicular types as well,it indicates that ubiquitous cellugyrin-positive vesicles may be formed in an activator protein(AP)3-dependent fashion.Furthermore,PI4P is known to recruit the adaptor complex AP1to the donor mem-branes(5).Thus,if cellugyrin-positive vesicles are in-deed formed via the AP3-mediated mechanism,our results suggest that recruitment of AP3to the mem-branes may be PI4P independent.This hypothesis deserves further investigation.Recently,Mora et al.(24)using confocal immuno-fluorescence microscopy found that PI4KIIIand its calcium-sensing partner neuronal calcium sensor-1 show a significant colocalization with Glut4in3T3-L1 adipocytes.Because PI4K type III is not present in small Glut4-vesicles(Refs.7and8and present paper), we suggest that PI4KIIImay colocalize with Glut4in some other intracellular compartment(s),e.g.in cis/ medial Golgi where PI4KIIIis abundant(25). MATERIALS AND METHODSMaterialsDexamethasone,3-isobutyl-1-methylxanthine,insulin,fetal bovine serum,and donkey serum were purchased from Sigma(St.Louis,MO).Aprotinin,leupeptin,pepstatin A,and phenylmethylsulfonyl fluoride were obtained from American Bioanalytical(Natick,MA).Calf serum,Lipofectamine2000, and DMEM were purchased from Invitrogen(Carlsbad,CA).AntibodiesA monoclonal anti-Glut4antibody1F8(26)and a rabbit poly-clonal antibody against cellugyrin(22)were described previ-ously.Rabbit polyclonal antibodies against PI4KII␣and PI4KIIwere kind gifts from Dr.Pietro De Camilli(Yale Uni-versity School of Medicine,New Haven,CT).The monoclonal antibody against the myc epitope was purchased from Cell Signaling Technology(Beverly,MA).Engineering of PI4KII␣and PI4KIIConstructsThe cDNA(IMAGE clone indentification no.2905670)encod-ing human PI4KII␣and the cDNA(IMAGE clone identification no.6335661)encoding mouse PI4KIIwere purchased from American Type Culture Collection(Manassas,VA)and In-vitrogen,respectively.PI4KII␣and PI4KIIopen reading frames were amplified by PCR and subcloned into pCDNA3.1 His B vector(Invitrogen)via Hin dIII and Eco RI sites.Myc tags were introduced to the5Ј-ends of the open reading frames via sense primers.For better expression in mammalian cells, Kozak sequences were included in the sense primers.Four mutants of PI4KII␣with the truncated N terminus(a.a.94–479,104–479,125–479,147–479)were obtained with the help of PCR.The sense primers for PCR were:PI4KII␣full length,5Ј-CGCAAGCTTACCACCATGGAACAAAAACTCATCTCA-GAAGAGGATCTGGACGAGACGAGCCC-3Ј,PI4KII␣94–479,5Ј-CGCAAGCTTACCACCATGGAACAAAAACTCATCTCA-GAAGAGGATCTG GCCGCTCAGGCCCAC-3Ј,PI4KII␣104–479,5Ј-CGCAAGCTTACCACCATGGAACAAAAACTCATCTCA-GAAGAGGATCTGTTCCCGGAGGATCCTG-3Ј,PI4KII␣125–479,5Ј-CGCAAGCTTACCACCATGGAACAAAAACTCATCTCA-GAAGAGGATCTGATCTTTCCCGAGCGCATC-3Ј, PI4KII␣147–479,5Ј-CGCAAGCTTACCACCATGGAACAAAAACTCATCTCA-GAAGAGGATCTGATCATTGCTGTCTTCAAACCC-3Ј, PI4KIIfull length,5Ј-GGCAAGCTTACCACCATGGAACAAAAACTCATCTC-AGAAGAGGATCTGGCGGAGGCCTGCGAG-3ЈThe antisense primer for PI4KII␣constructs was5Ј-GCG-AATTCCTACCACCATGAAAAGAAGGG-3Ј.The antisense primer for PI4KIIconstruct was5Ј-GCG-AATTCCTACCAGGAGGAGAAGAACGG-3Ј.RNA Interference ConstructsPI4KII␣shRNA construct was created using the sequence between nucleotides888and908(GenBank accession no. NM_18425)(5)and the protocol for the design and creation of PCR-based shRNA available at : 9331/RNAi_web/scripts/main2.pl.Resulting shRNA(5Ј-TGC-TGTTGACAGTGAGCGCTGAAGCAGAACCTCTTCCTGATA-GTGAAGCCACAGATGTATCAGGAAGAGGTTCTGCTTCAA-TGCCTACTGCCTCGGA-3Ј)was amplified by PCR using the following primers:5Ј-CAGAAGGCTCGAGAAGGTATATTGCTGTTGACAGT-GAGCG-3Јand5Ј-CTAAAGTAGCCCCTTGAATTCCGAGGC-AGTAGGCA-3Ј.The PCR product was digested with Xho I and Eco RI and cloned into the pSM2vector(Open Biosys-tems,Huntsville,AL).Cell CultureMurine3T3-L1preadipocytes were cultured,differentiated, and maintained as described previously(22).Briefly,cells were grown in DMEM supplemented with10%calf serumXu et al.•PI4KII␣in Cellugyrin-Positive Vesicles Mol Endocrinol,November2006,20(11):2890–28972895until confluence.The cells were transferred2d later to dif-ferentiation medium(DMEM containing10%fetal bovine se-rum,0.5m M3-isobutyl-1-methylxanthine,1M dexametha-sone,and 1.7M insulin).After48h,the differentiation medium was replaced with maintenance medium(DMEMsupplemented with10%fetal bovine serum).The mainte-nance medium was changed every48h.Before each exper-iment,cells were starved in serum-free media for2h.HEK293FT cells were cultured in DMEM supplementedwith10%fetal bovine serum plus2m M L-glutamine,100U/mlpenicillin,and100g/ml streptomycin.Transient transfec-tions were performed according to the manufacturer’s in-structions,and cells were used48h after transfection.To establish a stable PI4KII␣knockout cell line,the pSM2 vector with and without PI4KII␣shRNA was transfected into HEK293cells using lipofectamine2000,and7.5g/ml puro-mycin was added to the media1d after transfection.Selec-tion was carried out for2wk,and the pooled population ofcells was used.Subcellular Fractionation3T3-L1adipocytes(d8after initiation of differentiation)werewashed twice with37C DMEM and then serum starved for2h.Cells were treated with either100n M insulin or withcarrier(5m M HCl)in DMEM for15min at37C,and KCN wasadded to the cells at a final concentration of0.2m M.Cellswere washed three times and were homogenized in PBS withthe protease inhibitor cocktail(1M aprotinin,1M pepstatin, 1M leupeptin,1m M phenylmethylsulfonyl fluoride)using a ball-bearing homogenizer(Isobiotec,Heidelberg,Germany)with a12-m clearance.The homogenate was fractionated by differential centrifugation into plasma membrane(PM),heavy microsomes(HM),and light microsomes(LM)as pre-viously described(27,28).Alternatively,the homogenate wascentrifuged at16,000ϫg for20min to pellet PM and otherheavy membranes,and supernatant of this centrifugationwhich contained HM and LM,as well as free soluble proteins,was used for further experiments.HEK-293FT cells were homogenized using the ball-bear-ing homogenizer as described above.The homogenate wascentrifuged at500ϫg for5min to generate the postnuclearsupernatant(PNS).The PNS was then centrifuged at27,000ϫg for35min,and the resulting supernatant wasanalyzed by sucrose gradient centrifugation.Sucrose Gradient CentrifugationSamples(0.2ml)were loaded onto a4.6-ml continuous10–30%(wt/wt)sucrose gradient and centrifuged in a BeckmanSW-55Ti rotor at48,000rpm for indicated periods of time.Each gradient was fractionated into23–25fractions startingfrom the bottom of the tube.ImmunoadsorptionAffinity-purified1F8antibody and anticellugyrin antibody,aswell as nonspecific mouse or rabbit IgG(Sigma),were eachcoupled to Dynal magnetic beads(Dynal Biotech,Carlsbad,CA)according to the manufacturer’s ually,2g of each antibody was taken for30l of the beads.Before use,the antibody-coupled beads were blocked with1%BSAin PBS for30min at4C,followed by a wash with cold PBS.The16,000ϫg supernatants(600g)from3T3-L1adipo-cytes were incubated with30l1F8beads,anticellugyrin beads,or nonspecific IgG beads overnight at4C with gentle shaking.The beads were washed three times with PBS and then eluted with1%Triton X-100in PBS for1h at4C.After Triton elution,the beads were washed three times with PBS and eluted with nonreducing Laemmli sample buffer.Gel Electrophoresis and Western BlottingProteins were separated in SDS-polyacrylamide gels accord-ing to Laemmli(16),but without reducing agents,and trans-ferred to an Immobilon-P membrane(Millipore Corp.,Bed-ford,MA)in25m M Tris,192m M glycine.After transfer,the membrane was blocked with10%nonfat milk in PBS with 0.5%Tween20for1h at37C.The blots were probed with specific antibodies and horseradish peroxidase-conjugated secondary antibodies(Sigma)and detected with an en-hanced chemiluminescence substrate kit(PerkinElmer Life Sciences,Boston,MA)using a Kodak Image Station440CF (Eastman Kodak,Rochester,NY).The signals were quantified using the Kodak1D image analysis software.Immunofluorescence3T3-L1adipocytes stably expressing cellugyrin-enhanced green fluorescent protein(EGFP)were grown and differenti-ated as described above.On d7of differentiation,cells were trypsinized and replated on coverslips in12-well plates.The following day,cells were serum starved in DMEM for2h, washed once with PBS,and then fixed with4%formalde-hyde in PBS for30min at room temperature.Cells were washed twice with PBS and permeabilized with PBS contain-ing0.2%Triton X-100for5min at room temperature.The cells were then rinsed three times with PBS followed by blocking for1h at room temperature in PBS containing5% donkey serum and5%BSA(blocking solution).The cells were then incubated for1h with a polyclonal antibody against PI4KII␣at a dilution of1:1000in the blocking solution at room temperature.Cells were rinsed six times with PBS, covered with aluminum foil,and incubated for another hour at room temperature with Cy3-labeled antirabbit secondary an-tibody(Jackson ImmunoResearch Laboratories,West Grove, PA)diluted1:1000in blocking solution.The cells were washed six times with PBS and mounted on slides with the help of SlowFade Antifade Kit(Molecular Probes,Eugene, OR).Stained cells were visualized with the help of the Axio-vert200M microscope(Carl Zeiss,Thornwood,NY).Pictures were taken using the Axiovision3.0software(Carl Zeiss).PI4K AssaySamples(5l)were mixed with50g of phosphatidyl inositol (Avanti Polar Lipids,Alabaster,AL)and Triton X-100(0.4% final concentration)in PI4K buffer(30m M HEPES,pH7.4;100 m M NaCl;2m M MgCl2;0.5mg/ml BSA)in a total volume of50l.The reaction was initiated by the addition of40M ATP(10Ci of[␥-32P]ATP per assay)and terminated after a10-min incubation at room temperature by the addition of100l of 1M HCl.Lipids were extracted with160l of the chloroform-methanol mixture(1:1)by vortexing,and the samples were microfuged for5min.The lower phase was extracted with80l methanol/100m M HCl with2m M EDTA(1:1),and the samples were centrifuged again in the same regimen.The lower phase of the second extraction was collected and subjected to thin layer chromatography on potassium ox-alate-pretreated silica gel60plates(Whatman,Florham Park, NJ)using chloroform-acetone-methanol-acetic acid-water (60:23:20:18:12)as a mobile mercial phosphati-dylinositol,phosphatidylinositol4-phosphate,and phospha-tidylinositol-4,5-biphosphate(Avanti Polar Lipids)were used as standards.They were visualized with iodine vapor and marked with fluorescent labels.32P-labeled phosphoinositi-des were detected by autoradiography using the InstantIm-ager(PerkinElmer).AcknowledgmentsWe thank Dr.Lin V.Li(Boston University School of Med-icine)for3T3-L1cell line stably expressing cellugyrin-EGFP2896Mol Endocrinol,November2006,20(11):2890–2897Xu et al.•PI4KII␣in Cellugyrin-Positive Vesicles。
SCI写作句型汇总
S C I论文写作中一些常用的句型总结(一)很多文献已经讨论过了一、在Introduction里面经常会使用到的一个句子：很多文献已经讨论过了。
它的可能的说法有很多很多，这里列举几种我很久以前搜集的：A.??Solar energy conversion by photoelectrochemical cells?has been intensively investigated.?(Nature 1991, 353, 737 - 740?)B.?This was demonstrated in a number of studies that?showed that composite plasmonic-metal/semiconductor photocatalysts achieved significantly higher rates in various photocatalytic reactions compared with their pure semiconductor counterparts.C.?Several excellent reviews describing?these applications are available, and we do not discuss these topicsD.?Much work so far has focused on?wide band gap semiconductors for water splitting for the sake of chemical stability.（DOI:10.1038/NMAT3151）E.?Recent developments of?Lewis acids and water-soluble organometalliccatalysts?have attracted much attention.（Chem. Rev. 2002, 102, 3641?3666）F.?An interesting approach?in the use of zeolite as a water-tolerant solid acid?was described by?Ogawa et al（Chem.Rev. 2002, 102, 3641?3666）G.?Considerable research efforts have been devoted to?the direct transition metal-catalyzed conversion of aryl halides toaryl nitriles. (J. Org. Chem. 2000, 65, 7984-7989) H.?There are many excellent reviews in the literature dealing with the basic concepts of?the photocatalytic processand the reader is referred in particular to those by Hoffmann and coworkers,Mills and coworkers, and Kamat.(Metal oxide catalysis,19,P755)I. Nishimiya and Tsutsumi?have reported on（proposed）the influence of the Si/Al ratio of various zeolites on the acid strength, which were estimated by calorimetry using ammonia. (Chem.Rev. 2002, 102, 3641?3666)二、在results and discussion中经常会用到的：如图所示A. GIXRD patterns in?Figure 1A show?the bulk structural information on as-deposited films.?B.?As shown in Figure 7B,?the steady-state current density decreases after cycling between 0.35 and 0.7 V, which is probably due to the dissolution of FeOx.?C.?As can be seen from?parts a and b of Figure 7, the reaction cycles start with the thermodynamically most favorable VOx structures（J. Phys. Chem. C 2014, 118, 24950?24958）这与XX能够相互印证：A.?This is supported by?the appearance in the Ni-doped compounds of an ultraviolet–visible absorption band at 420–520nm (see Fig. 3 inset), corresponding to an energy range of about 2.9 to 2.3 eV.B. ?This?is consistent with the observation from?SEM–EDS. (Z.Zou et al. / Chemical Physics Letters 332 (2000) 271–277)C.?This indicates a good agreement between?the observed and calculated intensities in monoclinic with space groupP2/c when the O atoms are included in the model.D. The results?are in good consistent with?the observed photocatalytic activity...E. Identical conclusions were obtained in studies?where the SPR intensity and wavelength were modulated by manipulating the composition, shape,or size of plasmonic nanostructures.?F.??It was also found that areas of persistent divergent surfaceflow?coincide?with?regions where convection appears to be consistently suppressed even when SSTs are above 27.5°C.(二)1. 值得注意的是...A.?It must also be mentioned that?the recycling of aqueous organic solvent is less desirable than that of pure organic liquid.B.?Another interesting finding is that?zeolites with 10-membered ring pores showed high selectivities (>99%) to cyclohexanol, whereas those with 12-membered ring pores, such as mordenite, produced large amounts of dicyclohexyl ether. (Chem. Rev. 2002, 102,3641?3666)C.?It should be pointed out that?the nanometer-scale distribution of electrocatalyst centers on the electrode surface is also a predominant factor for high ORR electrocatalytic activity.D.?Notably,?the Ru II and Rh I complexes possessing the same BINAP chirality form antipodal amino acids as the predominant products.?(Angew. Chem. Int. Ed., 2002, 41: 2008–2022)E. Given the multitude of various transformations published,?it is noteworthy that?only very few distinct?activation?methods have been identified.?(Chem. Soc. Rev., 2009,?38, 2178-2189)F.?It is important to highlight that?these two directing effects will lead to different enantiomers of the products even if both the “H-bond-catalyst” and the?catalyst?acting by steric shielding have the same absolute stereochemistry. (Chem. Soc. Rev.,?2009,?38, 2178-2189)G.?It is worthwhile mentioning that?these PPNDs can be very stable for several months without the observations of any floating or precipitated dots, which is attributed to the electrostatic repulsions between the positively charge PPNDs resulting in electrosteric stabilization.(Adv. Mater., 2012, 24: 2037–2041)2.?...仍然是个挑战A.?There is thereby an urgent need but it is still a significant challenge to?rationally design and delicately tail or the electroactive MTMOs for advanced LIBs, ECs, MOBs, and FCs.?（Angew. Chem. Int. Ed.2 014, 53, 1488 – 1504）B.?However, systems that are?sufficiently stable and efficient for practical use?have not yet been realized.C.??It?remains?challenging?to?develop highly active HER catalysts based on materials that are more abundant at lower costs. (J. Am. Chem.Soc.,?2011,?133, ?7296–7299)D.?One of the?great?challenges?in the twenty-first century?is?unquestionably energy storage. (Nature Materials?2005, 4, 366 - 377?)众所周知A.?It is well established (accepted) / It is known to all / It is commonlyknown?that?many characteristics of functional materials, such as composition, crystalline phase, structural and morphological features, and the sur-/interface properties between the electrode and electrolyte, would greatly influence the performance of these unique MTMOs in electrochemical energy storage/conversion applications.（Angew. Chem. Int. Ed.2014,53, 1488 – 1504）B.?It is generally accepted (believed) that?for a-Fe2O3-based sensors the change in resistance is mainly caused by the adsorption and desorption of gases on the surface of the sensor structure. (Adv. Mater. 2005, 17, 582)C.?As we all know,?soybean abounds with carbon,?nitrogen?and oxygen elements owing to the existence of sugar,?proteins?and?lipids. (Chem. Commun., 2012,?48, 9367-9369)D.?There is no denying that?their presence may mediate spin moments to align parallel without acting alone to show d0-FM. (Nanoscale, 2013,?5, 3918-3930)(三)1. 正如下文将提到的...A.?As will be described below（也可以是As we shall see below）,?as the Si/Al ratio increases, the surface of the zeolite becomes more hydrophobic and possesses stronger affinity for ethyl acetate and the number of acid sites decreases.（Chem. Rev. 2002, 102, 3641?3666）B. This behavior is to be expected and?will?be?further?discussed?below. (J. Am. Chem. Soc.,?1955,?77, 3701–3707)C.?There are also some small deviations with respect to the flow direction,?whichwe?will?discuss?below.（Science, 2001, 291, 630-633）D.?Below,?we?will?see?what this implies.E.?Complete details of this case?will?be provided at a?later?time.E.?很多论文中，也经常直接用see below来表示，比如：The observation of nanocluster spheres at the ends of the nanowires is suggestive of a VLS growth process (see?below). (Science, 1998, ?279, 208-211)2. 这与XX能够相互印证...A.?This is supported by?the appearance in the Ni-doped compounds of an ultraviolet–visible absorption band at 420–520 nm (see Fig. 3 inset), corresponding to an energy range of about 2.9 to 2.3 eVB.This is consistent with the observation from?SEM–EDS. (Chem. Phys. Lett. 2000, 332, 271–277)C.?Identical conclusions were obtained?in studies where the SPR intensity and wavelength were modulated by manipulating the composition, shape, or size of plasmonic nanostructures.?（Nat. Mater. 2011, DOI: 10.1038/NMAT3151）D. In addition, the shape of the titration curve versus the PPi/1 ratio,?coinciding withthat?obtained by fluorescent titration studies, suggested that both 2:1 and 1:1 host-to-guest complexes are formed. (J. Am. Chem. Soc. 1999, 121, 9463-9464)E.?This unusual luminescence behavior is?in accord with?a recent theoretical prediction; MoS2, an indirect bandgap material in its bulk form, becomes a direct bandgapsemiconductor when thinned to a monolayer.?(Nano Lett.,?2010,?10, 1271–1275)3.?我们的研究可能在哪些方面得到应用A.?Our ?ndings suggest that?the use of solar energy for photocatalytic watersplitting?might provide a viable source for?‘clean’ hydrogen fuel, once the catalyticef?ciency of the semiconductor system has been improved by increasing its surface area and suitable modi?cations of the surface sites.B. Along with this green and cost-effective protocol of synthesis,?we expect that?these novel carbon nanodots?have potential applications in?bioimaging andelectrocatalysis.(Chem. Commun., 2012,?48, 9367-9369)C.?This system could potentially be applied as?the gain medium of solid-state organic-based lasers or as a component of high value photovoltaic (PV) materials, where destructive high energy UV radiation would be converted to useful low energy NIR radiation. (Chem. Soc. Rev., 2013,?42, 29-43)D.?Since the use of?graphene?may enhance the photocatalytic properties of TiO2?under UV and visible-light irradiation,?graphene–TiO2?composites?may potentially be usedto?enhance the bactericidal activity.?(Chem. Soc. Rev., 2012,?41, 782-796)E.??It is the first report that CQDs are both amino-functionalized and highly fluorescent,?which suggests their promising applications in?chemical sensing.(Carbon, 2012,?50,?2810–2815)(四)1. 什么东西还尚未发现/系统研究A. However,systems that are sufficiently stable and efficient for practical use?have not yet been realized.B. Nevertheless,for conventional nanostructured MTMOs as mentioned above,?some problematic disadvantages cannot be overlooked.（Angew. Chem. Int. Ed.2014,53, 1488 – 1504）C.?There are relatively few studies devoted to?determination of cmc values for block copolymer micelles. (Macromolecules 1991, 24, 1033-1040)D. This might be the reason why, despite of the great influence of the preparation on the catalytic activity of gold catalysts,?no systematic study concerning?the synthesis conditions?has been published yet.?(Applied Catalysis A: General2002, 226, ?1–13)E.?These possibilities remain to be?explored.F.??Further effort is required to?understand and better control the parameters dominating the particle surface passivation and resulting properties for carbon dots of brighter photoluminescence. (J. Am. Chem. Soc.,?2006,?128?, 7756–7757)2.?由于/因为...A.?Liquid ammonia?is particularly attractive as?an alternative to water?due to?its stability in the presence of strong reducing agents such as alkali metals that are used to access lower oxidation states.B.?The unique nature of?the cyanide ligand?results from?its ability to act both as a σdonor and a π acceptor combined with its negativecharge and ambidentate nature.C.?Qdots are also excellent probes for two-photon confocalmicroscopy?because?they are characterized by a very large absorption cross section?(Science ?2005,?307, 538-544).D.?As a result of?the reductive strategy we used and of the strong bonding between the surface and the aryl groups, low residual currents (similar to those observed at a bare electrode) were obtained over a large window of potentials, the same as for the unmodified parent GC electrode. (J. Am. Chem. Soc. 1992, 114, 5883-5884)E.?The small Tafel slope of the defect-rich MoS2 ultrathin nanosheets is advantageous for practical?applications,?since?it will lead to a faster increment of HER rate with increasing overpotential.(Adv. Mater., 2013, 25: 5807–5813)F. Fluorescent carbon-based materials have drawn increasing attention in recent years?owing to?exceptional advantages such as high optical absorptivity, chemical stability, biocompatibility, and low toxicity.(Angew. Chem. Int. Ed., 2013, 52: 3953–3957)G.??On the basis of?measurements of the heat of immersion of water on zeolites, Tsutsumi etal. claimed that the surface consists of siloxane bondings and is hydrophobicin the region of low Al content. (Chem. Rev. 2002, 102, 3641?3666)H.?Nanoparticle spatial distributions might have a large significance for catalyst stability,?given that?metal particle growth is a relevant deactivation mechanism for commercial catalysts.?3. ...很重要A.?The inhibition of additional nucleation during growth, in other words, the complete separation?of nucleation and growth,?is?critical(essential, important)?for?the successful synthesis of monodisperse nanocrystals. (Nature Materials?3, 891 - 895 (2004))B.??In the current study,?Cys,?homocysteine?(Hcy) and?glutathione?(GSH) were chosen as model?thiol?compounds since they?play important (significant, vital, critical) roles?in many biological processes and monitoring of these?thiol?compounds?is of great importance for?diagnosis of diseases.(Chem. Commun., 2012,?48, 1147-1149)C.?This is because according to nucleation theory,?what really matters?in addition to the change in temperature ΔT?(or supersaturation) is the cooling rate.(Chem. Soc. Rev., 2014,?43, 2013-2026)(五)1. 相反/不同于A.?On the contrary,?mononuclear complexes, called single-ion magnets (SIM), have shown hysteresis loops of butterfly/phonon bottleneck type, with negligiblecoercivity, and therefore with much shorter relaxation times of magnetization. (Angew. Chem. Int. Ed., 2014, 53: 4413–4417)B.?In contrast,?the Dy compound has significantly larger value of the transversal magnetic moment already in the ground state (ca. 10?1?μB), therefore allowing a fast QTM. （Angew. Chem. Int. Ed., 2014, 53: 4413–4417）C.?In contrast to?the structural similarity of these complexes, their magnetic behavior exhibits strong divergence.?(Angew. Chem. Int. Ed., 2014, 53: 4413–4417)D.?Contrary to?other conducting polymer semiconductors, carbon nitride ischemically and thermally stable and does not rely on complicated device manufacturing. (Nature materials, 2009, 8(1): 76-80.)E.?Unlike?the spherical particles they are derived from that Rayleigh light-scatter in the blue, these nanoprisms exhibit scattering in the red, which could be useful in developing multicolor diagnostic labels on the basis not only of nanoparticle composition and size but also of shape. (Science 2001,? 294, 1901-1903)2. 发现，阐明，报道，证实可供选择的词包括：verify, confirm, elucidate, identify, define, characterize, clarify, establish, ascertain, explain, observe, illuminate, illustrate，demonstrate, show, indicate, exhibit, presented, reveal, display, manifest，suggest, propose, estimate, prove, imply, disclose，report, describe，facilitate the identification of?举例：A. These stacks appear as nanorods in the two-dimensional TEM images, but tilting experiments?confirm that they are nanoprisms.?(Science 2001,? 294, 1901-1903)B. Note that TEM?shows?that about 20% of the nanoprisms are truncated.?(Science 2001,? 294, 1901-1903)C. Therefore, these calculations not only allow us to?identify?the important features in the spectrum of the nanoprisms but also the subtle relation between particle shape and the frequency of the bands that make up their spectra.?(Science 2001,? 294, 1901-1903)D. We?observed?a decrease in intensity of the characteristic surface plasmon band in the ultraviolet-visible (UV-Vis) spectroscopy for the spherical particles at λmax?= 400 nm with a concomitant growth of three new bands of λmax?= 335 (weak), 470 (medium), and 670 nm (strong), respectively. (Science 2001,? 294, 1901-1903)E. In this article, we present data?demonstrating?that opiate and nonopiate analgesia systems can be selectively activated by different environmental manipulationsand?describe?the neural circuitry involved. (Science 1982, 216, 1185-1192)F. This?suggests?that the cobalt in CoP has a partial positive charge (δ+), while the phosphorus has a partial negative charge (δ?),?implying?a transfer of electron density from Co to P.?(Angew. Chem., 2014, 126: 6828–6832)3. 如何指出当前研究的不足A. Although these inorganic substructures can exhibit a high density of functional groups, such as bridging OH groups, and the substructures contribute significantly to the adsorption properties of the material,surprisingly little attention has been devoted to?the post-synthetic functionalization of the inorganic units within MOFs. (Chem. Eur. J., 2013, 19: 5533–5536.)B.?Little is known,?however, about the microstructure of this material. (Nature Materials 2013,12, 554–561)C.?So far, very little information is available, and only in?the absorber film, not in the whole operational devices. （Nano Lett.,?2014,?14?(2), pp 888–893）D.?In fact it should be noted that very little optimisation work has been carried out on?these devices. (Chem. Commun., 2013,?49, 7893-7895)E. By far the most architectures have been prepared using a solution processed perovskite material,?yet a few examples have been reported that?have used an evaporated perovskite layer. (Adv. Mater., 2014, 27: 1837–1841.)F. Water balance issues have been effectively addressed in PEMFC technology through a large body of work encompassing imaging, detailed water content and water balance measurements, materials optimization and modeling,?but very few of these activities have been undertaken for?anion exchange membrane fuel cells,? primarily due to limited materials availability and device lifetime. (J. Polym. Sci. Part B: Polym. Phys., 2013, 51: 1727–1735)G. However,?none of these studies?tested for Th17 memory, a recently identified T cell that specializes in controlling extracellular bacterial infections at mucosal surfaces. (PNAS, 2013,?111, 787–792)H. However,?uncertainty still remains as to?the mechanism by which Li salt addition results in an extension of the cathodic reduction limit. (Energy Environ. Sci., 2014,?7, 232-250)I.?There have been a number of high profile cases where failure to?identify the most stable crystal form of a drug has led to severe formulation problems in manufacture. (Chem. Soc. Rev., 2014,?43, 2080-2088)J. However,?these measurements systematically underestimate?the amount of ordered material. ( Nature Materials 2013, 12, 1038–1044)(六)1.?取决于a.?This is an important distinction, as the overall activity of a catalyst will?depend on?the material properties, synthesis method, and other possible species that can be formed during activation.?(Nat. Mater.?2017,16,225–229)b.?This quantitative partitioning?was determined by?growing crystals of the 1:1 host–guest complex between?ExBox4+?and corannulene. (Nat. Chem.?2014,?6177–178)c.?They suggested that the Au particle size may?be the decisive factor for?achieving highly active Au catalysts.(Acc. Chem. Res.,?2014,?47, 740–749)d.?Low-valent late transition-metal catalysis has?become indispensable to?chemical synthesis, but homogeneous high-valent transition-metal catalysis is underdeveloped, mainly owing to the reactivity of high-valent transition-metal complexes and the challenges associated with synthesizing them.?(Nature2015,?517,449–454)e.?The polar effect?is a remarkable property that enables?considerably endergonic C–H abstractions?that would not be possible otherwise.?(Nature?2015, 525, 87–90)f.?Advances in heterogeneous catalysis?must rely on?the rational design of new catalysts. (Nat. Nanotechnol.?2017, 12, 100–101)g.?Likely, the origin of the chemoselectivity may?be also closely related to?the H?bonding with the N or O?atom of the nitroso moiety, a similar H-bonding effect is known in enamine-based nitroso chemistry. (Angew. Chem. Int. Ed.?2014, 53: 4149–4153)2.?有很大潜力a.?The quest for new methodologies to assemble complex organic molecules?continues to be a great impetus to?research efforts to discover or to optimize new catalytic transformations. (Nat. Chem.?2015,?7, 477–482)b.?Nanosized faujasite (FAU) crystals?have great potential as?catalysts or adsorbents to more efficiently process present and forthcoming synthetic and renewablefeedstocks in oil refining, petrochemistry and fine chemistry. (Nat. Mater.?2015, 14, 447–451)c.?For this purpose, vibrational spectroscopy?has proved promising?and very useful.?(Acc Chem Res. 2015, 48, 407–413.)d.?While a detailed mechanism remains to be elucidated and?there is room for improvement?in the yields and selectivities, it should be remarked that chirality transfer upon trifluoromethylation of enantioenriched allylsilanes was shown. (Top Catal.?2014,?57: 967.?)e.?The future looks bright for?the use of PGMs as catalysts, both on laboratory and industrial scales, because the preparation of most kinds of single-atom metal catalyst is likely to be straightforward, and because characterization of such catalysts has become easier with the advent of techniques that readily discriminate single atoms from small clusters and nanoparticles. (Nature?2015, 525, 325–326)f.?The unique mesostructure of the 3D-dendritic MSNSs with mesopore channels of short length and large diameter?is supposed to be the key role in?immobilization of active and robust heterogeneous catalysts, and?it would have more hopeful prospects in?catalytic applications. (ACS Appl. Mater. Interfaces,?2015,?7, 17450–17459)g.?Visible-light photoredox catalysis?offers exciting opportunities to?achieve challenging carbon–carbon bond formations under mild and ecologically benign conditions. (Acc. Chem. Res.,?2016, 49, 1990–1996)3. 因此同义词：Therefore, thus, consequently, hence, accordingly, so, as a result这一条比较简单，这里主要讲一下这些词的副词词性和灵活运用。
【国家自然科学基金】_π-π相互作用_基金支持热词逐年推荐_【万方软件创新助手】_20140730
生物矿化 生物信息学 爆炸力学 激发态 激光技术 沉降 水稻 桩筏基础 桩-土相互作用 桥梁工程 树突状细胞 构象 束缚极化子 机制 有限元方法 支持向量机 振动台 共振瑞利散射 元胞自动机 黑河流域 鲱鱼精dna 高血压 高次谐波 预测 非一致激励 静电相互作用 静电作用 陆气相互作用 阿米卡星 阻抗 铜 铁道工程 钯 钢筋混凝土 钢-混凝土组合梁 钌配合物 酞菁 配合物 鄂尔多斯盆地 边坡 输运 辐射谱 调制不稳定性 表面等离子共振 蛋白质-蛋白质相互作用 蛋白激酶c 药物相互作用 荧光性质 航空、航天推进系统 自电离态 自然边界 自发辐射 脂肪氧合酶 肿瘤细胞
人血清白蛋白 非线性光学 静电场 道路工程 运动原子 辐射修正 荧光探针 能量沉积 肿瘤 经济增长 紫外光谱 白血病 牛血红蛋白 湍流 混沌 气候变化 毛细管电泳 模拟 核磁共振 射流 基因 乳腺癌 黏弹性人工边界 高电荷态离子 非线性 陆面过程 镉 量子纠缠 量子干涉 重金属 重整化链图传播子 酿酒酵母 过氧化氢 转录因子 超短超强激光 血管生成 血管内皮生长因子 荧光 腔qed 脱氧核糖核酸(dna) 脱氧核糖核酸 肌红蛋白 聚苯胺 耦合模型 耦合 综述 细胞因子 细胞周期 细胞分化 细水雾 紫外-可见吸收光谱 系统动力学 粒子模拟 电子顺磁共振
6 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4
53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106
人体主要器官前缀医学英语
1．人体主要器官前缀名称通用名前（后）缀常用形容词示例心heart cardiao- cardial cardium/carditis/cardiology脑brain encepholo- cerebral cerebrum/encephalitis/encephalology肺lung pulmo- pulmonary pulmontiis/pulmonectomy/pulmonology肝liver hepato- hepatic hepatitis/hepatobiliary/hepatology胃stomach gastro- gastric gastritis/gastrointestinal/gastrology胆gallbladder chole- biliary holecystitis/cholinergic/cholecystectomy肠intestine entero- intestinal enteritis/enterectomy/enterology脾spleen splen- splenic splenitis/splenectomy/splenology胰pancreas pancreato- pancreatic pancreatitis/pancreatectomy肾kidney nephro- renal/nephric nephritis/nephropathy/nephrology 2．2．与人体系统、器官有关的前（后）缀名称通用名前（后）缀示例血 blood hemo-/hemato hematology/hemoglobin/hematoma血管 vessel vaso- vasopressor/cardiovasology/verebrovascular静脉 vein veno- venography/intravenous/venoconstriction动脉 artery arterio- arteriology/arteriole/arteriosclerosis肌 muscle myo- mycology/myositis/myocarditis髓 marrow myel-/myelo- myelocyte/myelitis/myeloma神经 nerve neur-/neyro- neurology/neuritis/neuron细胞 cell cyto-/-cyte cytology/cytoma/leukocyte尿 urine uro-/ur- urology/urosurgery/urogenital体 body somato-/some somatology/somatopsychic/chromosome3．4．与数字有关的前缀数字前缀示例一（单）mono-/uni- monomer/monoclone/carbon monoxide/unidirectional二 bi-/di- bilateral/biphasiccarbon dioxide/dipeptide三 tri- trilateral/triphasic/trigeminal nerve四 tetra- tetramer/tetracycline/tetraplegia五 penta- pentagon/pentachromic/pentachloride六hexa- hexachromic/benzene hexachloride(666)/hexacycliccompiund七 hepta- heptachromic/heptaploid/heptavalent八 octa- octahedral/octal system九 nona- nonapeptide/nonagon十 deca- decade/decagram/decaliter注：十位数的表示一般为：个位数前缀+deca，如：hexadecanol（十六烷醇），tetradecapeptidegastrin（十四肽胃泌素），octadecanoic acid（十八烷酸）5．4．颜色及与颜色有关的前缀颜色通用名前缀示例色 color chrom-/chromo- chromosome/chromatin/chromatometer红 red erythro- erythrocyte/erythrocyturia/erythrometer白 white leuko- leukocyte/leukemia/leukocytuira黑 black melano- melena/melanoma/melanoderma黄 yellow xantho- xanthopsin/xanthosis/xanthoma蓝 blue cyan-/cyano cyanosis/cyanopsia/cyanemia紫 violet/purple绿 green棕 brown brown mixture/brown ring橙 orange Victoria orange/ethyl orange/orange G粉红 pink oink frothy sputum绯红 crimson青铜 bronzed bronzed diabetes注：有些病名的“蓝”“紫”“青”为同义，其前缀都为“cyano-”. 6．7．5．与疾病和疾患有关的前（后）缀(1)含义前（后）缀形容词示例病 patho- pathogen/pathology/pathogenesis/-pathy -pathic neuropathy/nephropathy/adenopathy病态 -osis -otic neurosis/tuberculosis/schistosomiasis增多 leukocytosis/erythrocytopenia/granulocytosis减少-penia -penic leukocytopenia/erythrocytopenia/granulocytopenia无 a-/an- atypical/anuria/agranulocytopenia小/微 -let droplet/platelet/leafletmicro- microscopy/microorganism/micronucleus大/巨 macro- macroscopic/macronucleus/macrophage-megaly splenomegaly/acromegaly/hepatomegaly复合/多 poly- polyuria/polymer/polyopia全/泛 pan- pancolectomy/panmyelosis/pandemic6．与疾病和疾患有关的前（后）缀(2)含义前（后）缀示例相反 dis- disease/disorder/disability困难/障碍 dys- dysfunction/dyspepsia/dyspnea不良 mal- malfunction/malnutrition/malpractice炎症 -it is appendicitis/bronchitis/arthritis瘤/块 -oma lymphoma/adenoma/hematoma血症 -emia leukemia/septisemia/bacteremia痛 -algia/-algesia/alge-/algo- analgesia/hypoalgesia/algometer麻痹 -plegia hemipleia/pamplegia/myoplegia流出 -rrhea diarrhea/hypermenorrhea/rhinorrhea坏死 -necrosis necro-/necr- hepatonecrosis/myonecrosis/necrospermia 结石 litho-/-lith lithiasis/lithogenesis/cholelithes8．与方位有关的前缀含义通用词前缀示例上 upper/superior pi-/supra- epidemic/epithelium/supracostal下lower/inferior nfra-/sub- infracostal/subclavicular/subcutaneous前front/anterior/prior fore-/ante- forehead/anteroposterior/precirrhosis/pre-后back/posterior post-/retro- posthepatic/postprandial/retrocardiac内inner/internal in-/endo-/ento- inhalation/endoscopy/entocranial外 outer/external ex-/exo- extract/excretion/exocardial间 between inter- intermuscular/intercostal/intercourse旁/副 on the side of para- parathyroid/paraprotein/pararenal周 around peri- perioperative/pericarditis/peritoneum中心central centri-/centra- centrifugation/centralize/centronucleus/centro-反/对opposite counter-/contra- counterpart/countershock/contraindication注：in vivo/in’vaivou/活体内;in vitro/in vaitrou/活体外或试管内；in situ/in’saitju:/原位9．与外科手术有关的前（后）缀含义前（后）缀示例切除 -ectomy appendectomy/gastrectomy/splenectomy切开 -tomy tracheotomy/hysterotomy/craniotomy切（割） -tome tracheotome/thoracotome吻合 -stomy duodenoenterostomy/gastroesophagostomy成形术 -plasty tracheoplasty/osteoplasty/myoplasty整（矫）形 ortho- orthopedics/orthopod/orthotherapy造影 -graphy angiography/nephrography/phlebography经… trans- transdominal/translateral/transurethral注：ortho-也是“正”“原”的前缀，如：ortho-acid（正酸）-graphy为方法，如：electrocardigraphy心电图检查术；graph为仪器，如：electrocardigraph心电图机；gram 为图象，文字，如：electrocardiogram心电图记录。
Subthreshold Antiproton Spectra in Relativistic Heavy Ion Collisions
a rXiv:h ep-ph/959328v119Se p1995TPR-95-19Subthreshold Antiproton Spectra in Relativistic Heavy Ion Collisions Richard Wittmann and Ulrich Heinz Institut f¨u r Theoretische Physik,Universit¨a t Regensburg,D-93040Regensburg,Germany (February 1,2008)Abstract We study the structure of antiproton spectra at extreme subthreshold bom-barding energies using a thermodynamic picture.Antiproton production pro-cesses and final state interactions are discussed in detail in order to find out what can be learned about these processes from the observed spectra.Typeset using REVT E XI.INTRODUCTIONThere exist numerous examples for the production of particles in heavy ion collisions at bombarding energies well below the single nucleon-nucleon threshold[1].This phenomenon indicates collective interactions among the many participating nucleons and thus is expected to give information about the hot and dense matter formed in these collisions.At beam energies around1GeV per nucleon the most extreme of these subthreshold particles is the antiproton.Therefore,it is believed to be a very sensitive probe to collective behaviour in nucleus-nucleus collisions.However,presently neither the production mechanism nor thefinal state interactions of antiprotons in dense nucleonic matter are well understood.The antiproton yields measured at GSI and BEVALAC[2,3]seem to be described equally well by various microscopic models using different assumptions about the production mechanism and particle properties in dense nuclear matter[4–7].This ambiguity raises the question which kind of information can be really deduced from subthreshold¯p spectra.In this paper we use a simple thermodynamic framework as a background on wich we can systematically study the influence of different assumptions on thefinal¯p spectrum.In the next section we will focus on the production process.Following a discussion of thefinal state interactions of the antiproton in dense hadronic matter in Section III,we use in Section IV a one-dimensional hydrodynamic model for the explodingfireball to clarify which features of the production and reabsorption mechanisms should survive in thefinal spectra in a dynamical environment.We summarize our results in Section V.II.PRODUCTION OF ANTIPROTONS IN HEA VY ION COLLISIONSA.The Antiproton Production RateUnfortunately very little is known about the production mechanism for antiprotons in dense nuclear matter.Therefore,we are forced to use intuitive arguments to obtain aplausible expression for the production rate.As commonly done in microscopic models[8] we consider only two body collisions and take the experimentally measured cross sections for ¯p production in free NN collisions as input.The problem can then be split into two parts: the distribution of the two colliding nucleons in momentum space and the elementary cross sections for antiproton production.The procedure is later generalized to collisions among other types of particles(Section II C)using phase space arguments.Formally,the antiproton production rate P,i.e.the number of antiprotons produced in the space-time cell d4x and momentum space element d3p,is given by[9]P= i,j ds2w(s)d3σij→¯pδ(p2i−m2i)Θ(p0i).(2)(2π)3Finally,w(s,m i,m j)=√offinding two nucleons at a center-of-mass energys−4m)αIn order to obtain from the total cross section(3)a formula for the differential cross section,we assume like others that the momentum distribution of the produced particles is mainly governed by phase space.This leads to the simple relationshipd3σij→NNN¯pσij→NNN¯p(s).(4)R4(P)Here R n is the volume the n-particle phase space,which can be given analytically in the non-relativistic limit[12].P is the total4-momentum of the4-particlefinal state,which√reduces to(s min(p)/T.Hereρi,j are the densities of the incoming particles,that the cross section σij →NNN ¯p (s )is independent of the internal state of excitation of the colliding baryons in our thermal picture.The consequences of this assumption are quite obvious.While the distance to the ¯p -threshold is reduced by the larger rest mass of the resonances,the mean velocity of a heavy resonance state in a thermal system is smaller than that of a nucleon.Both factors counteract each other,and indeed we found that the total rate P is not strongly changed by the inclusion of resonances.The role of pionic intermediate states for ¯p -production in pp -collisions was pointed out by Feldman [15].As mesonsare created numerously in the course of a heavy ion collision,mesonic states gain even more importance in this case.In fact,Ko and Ge [13]claimed that ρρ→p ¯p should be the dominant production channel.Relating the ρρ-production channel to the p ¯p annihilation channel [13]byσρρ→p ¯p (s )= 2s −4m ρm σp ¯p →ρρ(s )(5)where S =1is the spin factor for the ρ,the production rate can be calculated straightfor-wardly from Eq.(1):P =g 2ρ(2π)516T .(6)The spin-isospin factor of the ρis g ρ=9,and E is the energy of the produced antiproton.The modified Bessel function K 1results from the assumption of local thermal equilibration for the ρ-distribution.Expanding the Bessel function for large values of 2E/T we see that the ”temperature”T ¯p of the ¯p -spectrum is only half the medium temperature:T ¯p =1w 2(s,m i ,m j )(8)Comparing this form with measured data onπ−p→np¯p collisions[16],a value ofσ0ij= 0.35mb is obtained.Due to the threshold behaviour of Eq.(8)and the rather large value ofσ0ij,it turns out[17]that this process is by far the most important one in a chemically equilibrated system.However,this chemical equilibration–if achieved at all–is reached only in thefinal stages of the heavy ion collision when cooling has already started.So it is by no means clear whether the dominance of the meson-baryon channel remains valid in a realistic collision scenario.This point will be further discussed in Section IV.III.FINAL STATE INTERACTION OF THE ANTIPROTONOnce an antiproton is created in the hot and dense hadronic medium,its state will be modified by interactions with the surrounding particles.Two fundamentally different cases have to be distinguished:elastic scattering,which leads to a reconfiguration in phase space, driving the momentum distribution towards a thermal one with the temperature of the surrounding medium,and annihilation.Each process will be considered in turn.A.Elastic ScatteringThe time evolution of the distribution function f(p,t)is generally described by the equation[18]f(p,t2)= w(p,p′;t2,t1)f(p′,t1)dp′(9) where w(p,p′;t2,t1)is the transition probability from momentum state p′at time t1to state p at t2.Because the number density of antiprotons is negligible compared to the total particle density in the system,the evolution of f(p,t)can be viewed as a Markov process.Assuming furthermore that the duration of a single scattering processτand the mean free pathλare small compared to the typical time scaleδt and length scaleδr which measure the variation of the thermodynamic properties of the system,τ≪δt,λ≪δr,Eq.(9)can be transformed into a master equation.Considering the structure of the differ-ential p¯p cross section one notices that in the interesting energy range it is strongly peaked in the forward direction[19–21].Therefore,the master equation can be approximated by a Fokker-Planck equation[22]:∂f(p,t)∂p A(p)f(p,t)+1∂2pD(p)f(p,t).(10)For the evaluation of the friction coefficient A and the diffusion coefficient D we follow the treatment described by Svetitsky[23].For the differential cross section we took a form suggested in[19]:dσ|t|2D/A(e2At−1)+2mT0p2≡exp −p2/2mT eff(t) .(14)This shows that the exponential shape of the distribution function is maintained throughout the time evolution,but that the slope T eff(t)gradually evolves from T0to the value D/mAwhich,according to the Einstein relation(12),is the medium temperature T.Looking at Fig.3it is clear that after about10fm/c the spectrum is practically thermalized.Therefore initial structures of the production spectrum(like the ones seen in Fig.2)are washed out quite rapidely,and their experimental observation will be very difficult.B.AnnihilationThe annihilation of antiprotons with baryons is dominated by multi-mesonfinal states X.For the parametrisation of the annihilation cross sectionσann(s)we take the form given in[14]for the process¯p+B−→X,B=N,∆, (15)Using the same philosophy as for the calculation of the production rate,a simple dif-ferential equation for the decrease of the antiproton density in phase space can be written down:dd3xd3p =−d6N(2π)3f i( x, p i,t)v i¯pσanni¯p≡−d6Nbecomes questionable.More reliable results should be based on a quantumfield theoretic calculation which is beyond the scope of this paper.IV.ANTIPROTON SPECTRA FROM AN EXPLODING FIREBALLA.A Model for the Heavy Ion CollisionIn order to compare the results of the two previous sections with experimental data we connect them through a dynamical model for the heavy ion reaction.In the spirit of our thermodynamic approach the so-called hadrochemical model of Montvay and Zimanyi [24]is applied for the simulation of the heavy ion collision.In this picture the reaction is split into two phases,an ignition and an explosion phase,and particles which have at least scattered once are assumed to follow a local Maxwell-Boltzmann distribution.In addition, a spherically symmetric geometry is assumed for the explosion phase.The included particle species are nucleons,∆-resonances,pions andρ-mesons.As initial condition a Fermi-type density distribution is taken for the nucleons of the incoming nuclei,ρ0ρ(r)=collision with momentum p z=±700MeV in the c.m.system.One clearly sees that at the moment of full overlap of the two nuclei a dense zone with hot nucleons,resonances and mesons(not shown)has been formed.Only in the peripheral regions”cold”target and projectile nucleons can still be found.On the other hand,chemical equilibrium of the hot collision zone is not reached in the short available time before the explosion phase sets in; pions and in particularρmesons remain far below their equilibrium abundances[17].It is important to note that due to the arguments given in Section II¯p production is strongly suppressed in this initial stage of the reaction.In our simple model we have in fact neglected this early¯p production completely.The ignition phase is only needed to obtain the chemical composition of the hotfireball which is expected to be the dominant source for the creation of antiprotons.For the subsequent expansion of the spherically symmetricfireball into the surrounding vacuum analytical solutions can be given if the equation of state of an ideal gas is taken as input[25].If excited states are included in the model,an exact analytical solution is no longer possible.Because a small admixture of resonaces is not expected to fundamentally change the dynamics of the system,we can account for their effect infirst order by adjusting only the thermodynamic parameters of the explodingfireball,but not the expansion velocity profiles.There is one free parameter in the model[24],α,which controls the density and the temperature profiles,respectively.Small valuesα→0representδ-function like density profiles whereasα→∞corresponds to a homogeneous density distribution throughout the fireball(square well profile).The time-dependent temperature profiles for two representative values ofαare shown in Fig.5for different times t starting at the time t m of full overlap of the nuclei.Clearly,a small value ofαleads to an unreasonably high temperature(T∼200MeV) in the core of thefireball at the beginning of the explosion phase,and should thus be considered unphysical.B.Antiproton Spectra from an Exploding FireballBased on the time-dependent chemical composition of this hadrochemical model we can calculate the spectrum of the antiprotons created in a heavy ion collision.Let usfirst con-centrate on the influence of the density distribution in thefireball characterized by the shape parameterα.Due to different temperature profiles connected with differentαvalues(see Fig.5)the absolute normalization varies substantially when the density profile is changed. For moreδ-like shapes an extremely hotfireball core is generated,whereas for increasingαboth density and temperature are more and more diffuse and spread uniformly over a wider area.Because of the exponential dependence upon temperature a small,but hot core raises the production rate drastically.This fact is illustrated in Fig.6for three values ofα.Not only the total normalization,but also the asymptotic slope of the spectrum is modified due to the variation of the core temperature withαas indicated in the Figure.Comparing the dotted lines,which give the pure production spectrum,to the solid lines representing the asymptotic spectrum at decoupling,the tremendous effect of antiproton absorption in heavy ion collisions is obvious.As one intuitively expects absorption is more pronounced for low-energetic antiprotons than for the high-energetic ones which have the opportunity to escape the high density zone earlier.Therefore,thefinally observed spectrum isflatter than the original production spectrum.Interestingly,while the baryon-baryon and theρρchannels are comparable in their con-tribution to¯p production,the pion-baryon channel turned out to be much more effective for all reasonable sets of parameters.This fact is indeed remarkable,because here,contrary to the discussion in Section II,the pions are not in chemical equilibrium;in our hadrochemical model the total time of the ignition phase is too short to saturate the pion channel.The meson-baryon channel is thus crucial for understanding¯p spectra.Only by including all channels reliable predictions about the antiprotons can be drawn.We did not mention so far that in our calculations we followed common practice and assumed afinite¯p formation time ofτ=1fm/c;this means that during this time intervalafter a¯p-producing collision the antiproton is assumed to be not yet fully developed and thus cannot annihilate.However,there are some(although controversial)experimental indications of an extremely long mean free path for antiprotons beforefinal state interactions set in[26].We have tested the influence of different values for the formation timeτon the¯p spectrum.Fig.7shows that this highly phenomenological and poorly established parameter has a very strong influence in particular on the absolute normalization of the spectra,i.e. the total production yield.In the light of this uncertainty it appears difficult to argue for or against the necessity for medium effects on the antiproton production threshold based on a comparison between theoretical and experimental total yields only.parison with Experimental DataIn all the calculations shown above a bombarding energy of1GeV/A has been assumed. Experimental data are,however,only available at around2GeV/A.At these higher energies thermalization becomes more questionable[27],and our simple model may be stretching its limits.Especially,the temperature in thefireball core becomes extremely high.In order to avoid such an unrealistic situation and in recognition of results from kinetic simulations [4,6,7]we thus assume that only part of the incoming energy is thermalized–in the following a fraction of70%was taken.Fig.8shows calculations for the antiproton spectrum from Na-Na and Ni-Ni collisions at a kinetic beam energy of2GeV/nucleon.The calculation assumes a¯p formation time of τ=1fm/c,and takes for the density and temperature profiles the parameter valueα=1 which corresponds to an upside-down parabola for the density profiparing with the GSI data[2]we see our model features too weak a dependence on the size of the collision system;the absolute order of magnitude of the antiproton spectrum is,however,correctly reproduced by our simple hadrochemical model,without adjusting any other parameters. No exotic processes for¯p production are assumed.As mentioned in the previous subsection, the pion-baryon channel is responsible for getting enough antiprotons in our model,withoutany need for a reduced effective¯p mass in the hot and dense medium[4,5].The existing data do not yet allow for a definite conclusion about the shape of the spectrum,and we hope that future experiments[28]will provide additional contraints for the model.V.CONCLUSIONSHeavy ion collisions at typical BEVALAC and SIS energies are far below the p¯p-production threshold.As a consequence,pre-equilibrium antiproton production in such collisions is strongly suppressed relative to production from the thermalized medium pro-duced in the later stages of the collision.Therefore,¯p production becomes important only when the heavy ion reaction is sufficiently far progressed,in accordance with microscopic simulations[4].By assuming a local Maxwell-Boltzmann distribution for the scattered and produced particles forming the medium in the collision zone one maximizes the¯p production rate(see Fig.1).If,contrary to the assumptions made in this work,the extreme states in phase space described by the tails of the thermal Boltzmann distribution are not populated, the antiproton yield could be reduced substantially.We also found that the threshold behaviour of the¯p production cross section is not only crucial for the total¯p yield,but also introduces structures into the initial¯p spectrum.This might give rise to the hope that by measuring the¯p momentum spectrum one may obtain further insight into the¯p production mechanism.On the other hand we saw here,using a Fokker-Plank description for the later evolution of the distribution function f¯p(p,t)in a hot environment,that these structures are largely washed out by subsequent elastic scattering of the¯p with the hadrons in the medium.In addition,the large annihilation rate reduces the number of observable antiprotons by roughly two orders of magnitude relative to the initial production spectrum;the exact magnitude of the absorption effect was found to depend sensitively on the choice of the¯p formation timeτ.We have also shown that meson(in particular pion)induced production channels con-tribute significantly to thefinal¯p yield and should thus not be neglected.We were thus ableto reproduce the total yield of the measured antiprotons in a simple model for the reaction dynamics without including,for example,medium effects on the hadron masses and cross sections[4,5].However,we must stress the strong sensitivity of the¯p yield on various unknown param-eters(e.g.the¯p formation time)and on poorly controlled approximations(e.g.the degree of population of extreme corners in phase space by the particles in the collision region),and emphasize the rapidly thermalizing effects of elasticfinal state interactions on the¯p momen-tum spectrum.We conclude that turning subthreshold antiproton production in heavy ion collisions into a quantitative probe for medium properties and collective dynamics in hot and dense nuclear matter remains a serious challenge.ACKNOWLEDGMENTSThis work was supported by the Gesellschaft f¨u r Schwerionenforschung(GSI)and by the Bundesministerium f¨u r Bildung und Forschung(BMBF).REFERENCES[1]U.Mosel,Annu.Rev.Nucl.Part.Sci.1991,Vol.41,29[2]A.Schr¨o ter et al.,Z.Phys.A350(1994)101[3]A.Shor et al.,Phys.Rev.Lett.63(1989)2192[4]S.Teis,W.Cassing,T.Maruyama,and U.Mosel,Phys.Rev.C50(1994)388[5]G.Q.Li and C.M.Ko,Phys.Rev.C50(1994)1725[6]G.Batko et al.,J.Phys.G20(1994)461[7]C.Spieles et al.,Mod.Phys.Lett.A27(1993)2547[8]G.F.Bertsch and S.Das Gupta,Phys.Rep.160(1988)189[9]P.Koch,B.M¨u ller,and J.Rafelski,Phys.Rep.42(1986)167[10]B.Sch¨u rmann,K.Hartmann,and H.Pirner,Nucl.Phys.A360(1981)435[11]G.Batko et al.,Phys.Lett.B256(1991)331[12]burn,Rev.Mod.Phys.27(1955)1,and references therein[13]C.M.Ko and X.Ge,Phys.Lett.B205(1988)195[14]P.Koch and C.Dover,Phys.Rev.C40(1989)145[15]G.Feldman,Phys.Rev.95(1954)1697[16]Landolt-B¨o rnstein,Numerical Data and Functional Relationships in Science and Tech-nology,Vol.12a und Vol.12b,Springer-Verlag Berlin,1988[17]R.Wittmann,Ph.D.thesis,Univ.Regensburg,Feb.1995[18]N.G.van Kampen,Stochastic Processes in Physics and Chemistry,North-Holland Pub-lishing Company,Amsterdam1983[19]B.Conforto et al.,Nouvo Cim.54A(1968)441[20]W.Br¨u ckner et al.,Phys.Lett.B166(1986)113[21]E.Eisenhandler et al.,Nucl.Phys.B113(1976)1[22]S.Chandrasekhar,Rev.Mod.Phys.15(1943)1[23]B.Svetitsky,Phys.Rev.D37(1988)2484[24]I.Montvay and J.Zimanyi,Nucl.Phys.A316(1979)490[25]J.P.Bondorf,S.I.A.Garpman,and J.Zim´a nyi,Nucl.Phys.A296(1978)320[26]A.O.Vaisenberg et al.,JETP Lett.29(1979)661[27]ng et al.,Phys.Lett.B245(1990)147[28]A.Gillitzer et al.,talk presented at the XXXIII International Winter Meeting on NuclearPhysics,23.-28.January1995,Bormio(Italy)FIGURES468101214-810-710-610-510-410-310-210-110010s in GeVλt=0.2 fm/c t=2 fm/c t=5 fm/c ©©©2FIG.1.λ(s,t )at different times t calculated from the model of Ref.[10].The starting point is a δ-function at s =5.5GeV 2.The dashed line is the asymptotic thermal distribution at t =∞),corresponding to a temperature T =133MeV.00.10.20.30.40.50.6-16-171010-1510-1410-1310-1210-1110-1010 E in GeVα = 1/2α = 3/2α = 5/2α = 7/2ÄÄÄÄPFIG.2.Antiproton production spectrum for different threshold behaviour of the elementaryproduction process (x =12,52from top to bottom).203040506070 8090t in fm/cT e f f T = 10 MeV 0T = 50 MeV 0T = 70 MeV 00 246810i n M e V 10FIG.3.Effective temperature T efffor three Maxwell distributions with initial temperatures T 0=10MeV,50MeV and 70MeV,respectively.0z in fm12ρ / ρ0FIG.4.Density distributions ρ(0,0,z )along the beam axis of target and projectile nucleons for a 40Ca-40Cacollision,normalized to ρ0=0.15fm −3.The solid lines labelled by “incoming nuclei”show the two nuclei centered at ±5fm at time t 0=0.The two other solid lines denote the cold nuclear remnants at full overlap time t m ,centered at about ±3fm.Also shown are fireball nucleons (long-dashed)and ∆-resonances (short-dashed)at time t m .α=0.20T i n G e V r in fm α=5r in fm024680.050.10.150.20.25T i n G e V t = 9 fm/c630FIG.5.Temperature profiles for α=0.2and α=5at four different times t =0(=beginning of the explosion phase)and t =3,6,and 9fm/c (from top to bottom).E in GeV33d N / d p i n G e V -3α=0.2α=1α=500.10.20.30.40.50.6-11-10-9-8-7-6-5-4-3101010101010101010FIG.6.¯p -spectra for different profile parameters α.The dotted lines mark the initial pro-duction spectra.The asymptotic temperatures at an assumed freeze-out density ρf =ρ0/2corre-sponding to the solid lines are,from top to bottom,105MeV,87MeV and 64MeV,respectively.E in GeVd N / d p i n Ge V 33-10101010101010FIG.7.¯p -spectrum for different formation times,for a profile parameter α=1.The dashed line indicates the original production spectrum.E in GeVkin d p 3d σ3i n b /Ge V /10101010FIG.8.Differential ¯p spectrum for Na-Na and Ni-Ni collisions,for a shape parameter α=1.The data are from GSI experiments [2].。
蛋白组学操作步骤
MAN0000518
User Manual
Table of Contents
Kit Contents and Storage.................................................................................................................................. iv
SILAC Protein Identification (ID) and Quantitation Kits
For identifying and quantifying phosphoproteins and membrane proteins
Catalog no. SP10001, SM10002, SP10005, SM10006 MS10030, MS10031, MS10032, MS10033
SILAC™ Phosphontents
The kit contents, shipping, and storage for SILAC™ Phosphoprotein and Membrane Protein ID and Quantitation Kits are listed below. For a detailed description of kit contents, see page 4. These kits include appropriate media components, amino acids, and Lysis Buffer. Store all media protected from light. SP10001 SP10005 SM10002 SM10006 Shipping Blue ice Blue ice Dry ice Dry ice Blue ice Blue ice Blue ice Blue ice Blue ice Blue ice Storage 4 C 4 C –20C –20C 4 C 4 C 4 C –20C 4 C 4 C
有机化学中常见名词中英文对照
学疏专业班级有机化学中常见名词中英文对照英中对照abietic acid （松香酸）acetal （缩醛）acid anhydride（酸Sf）A. Couper （古柏尔）acridine （卩丫唏）acronycine （山油柑碱）acidylating reaction（酰化反应）acyl group （酰基）acyl halide （酰卤）adenine （腺嚓吟）adrenal cortex hormone （肾上腺皮质激素）A. Kekule （开库勒）alanine （丙氨酸）alcoholysis （醇解）aldehyde （醛）alicyclic hydrocarbon（脂环炷）alizarin（茜草素）alizarin-type （茜素型）alkane （烷桂）alkene （烯桂）alkylation （傅-克烷基化反应）alkyne （烘炷）aloeemodin （芦荟大黃素）amines （胺类）amide （酰胺）amidino （腺基）amino acid （氨基酸）-aminobutyric acid （-氨基丁酸）ammonolysis （氨解）andiron formula （锯架式）andrographo 1 ide （穿心莲内酯）anisodine （樟柳碱）annulene （轮烯）anomer （异头物）anomeric effect （异头效应）anthocyanidin （花色素）anthraquinone （蔥醍）anthrol （蔥酚）anthrone （蔥酮）anthracene （蔥）anti aromaticity or anti aromatic compound （反芳香性化合物）apigenin （芹菜素）apple polyphenols （苹果多酚）aromatic compound （芳香性化合物）aromatic hydrocarbon （芳香绘）aromaticity （芳香性）aromatization （芳构化）arecoline （槟榔碱）arginine （精氨酸）aspartic acid （天冬氨酸）asymmetric carbon atom （手性碳原子）atomic orbital （原子轨道）A. Wurtz reaction （武兹反应）axial bond （直立键，& 键）azul 奥！（）Baeyer （拜耳）baicalein （黃苓素）baicalin （黃苓昔）barbital （巴比妥）barbituric acid（巴比妥酸）base complementary （碱基配对）benzoimidazole （苯并咪醴）benzothiazole （苯并唾I坐）学疏专业班级学号benzene （苯）berberine （小漿碱）Berzelius （伯察留史）beta-pleated sheet （-折叠）bi-anthracene nucleus （双蔥核）biological methylate （生物甲基化）biuret reaction（缩二服反应）□ bond （o 键）n bond （兀键）borneol （龙脑）Braun reaction （布朗反应）bridged hydrocarbon （桥环绘）bytrepob （布特力洛夫）camphor （樟脑）cardiac glycosides （强心昔）camptothecine （喜树碱）carotene （胡萝卜素）carthamin （红花昔）carbene （卡宾；碳烯）carbohydrate （碳水化合物）carbonyl 俄基）carboxyl （竣基）carboxylic acid（竣酸）cassiamine （山扁豆双醍）catechin （儿茶素）cellobiose （纤维二糖）cellulose （纤维素）cephalin（脑磷脂）chain carbon constitution （链状碳架）chain initiation step （链引发阶段）chain propagation step （链增长阶段）chain termination step （链终止阶段）chaicone （查尔酮）charge-transfer complex （电荷转移络合物）chemical bond （化学键）chemocholic acid（鹅去氧胆酸）chirality （手性）chitin （甲壳质）chitosamine （壳糖胺）chlorophyll （叶绿素）cholalic acid （胆笛酸）cholestane （胆縉烷）cholesterol （胆笛醇）chromatography （色谱法）chrysophanol 9-anthrone （9-蔥酮大黃酚）chrysarobin （柯械素）cinchonine （金鸡宁）cis-trans isomer （顺反异构体）cistrans isomerism （顺反异构）citral （柠檬醛）Claisen rearrangement （克莱森重排）Claisen-Schmidt reaction （克莱森一斯密特反应）cocaine （古柯碱）codonopsine （党参碱）concerted reaction （协同反应）condensed nuclei hydrocarbon （稠环坯）conformation （构象）conformational isomerism （构象异构）coniine （毒芹碱）conjugated diene （共辘二烯桂）conjugation system （共轨体系）conjugative effect （共轨效应）conservation of orbital symmetry （分子轨道对称性守恒理论）constitutional isomerism （构造异构）coprostane （粪笛烷）学疏专业班级学号cortisone （可的松）crown ether （冠瞇）cumulative diene （聚集二烯婭）curcumenol （莪术醇）cyanidin （矢车菊素）cyclic carbon constitution （环状碳架）cycloaddition recation （环力口成反应）cycloalkane （脂环桂）cyclodextrin （环糊精）cysteine （半胱氨酸）daidzein （大豆黃素）Darzens reaction（达尔森反应）decarboxylation （脱竣反应）delocaization（离域）delocalization energy（离域能）delocalized electron （离域电子）delocalized energy（离域能）delphinidin（飞燕草素）denature （变性）deoxyribonuc 1 eic acid（脱氧核糖核酸）derivative of carboxylic acid （竣酸衍生物）diastereoisomer （非对映体）学疏专业班级学号diazonium salt （重氮盐）chborane （乙硼烷）dichlorocarbene （•二氯卡宾）P -dichroine （ P -常山碱）Diels一Alder reaction （狄尔斯一阿尔德反应）diene （双烯体，二烯婭）dienophile （亲双烯体）dihydrochalcone （.：氢查尔酮）B —dihydrotheelin （ B —雌二醇）distillation （蒸镭法）diterpenoids （二？£类）effective atomic number （有效原子序数）E.J. Cory—H. House reaction （科瑞一郝思反应）electric field scan （电场扫描）18-electron rule （18 电子规则）electromeric effect （电性效应）electrophilic addition （亲电加成反应）electrophilic substitution （亲电取代）electrophile （亲电性试剂）elimination reaction （消除反应）Emde degradation （埃姆徳降解）1- emetine（1-吐根碱）emodin-type （大黄素型）enantiomerism （对映异构）enantiomer （对映体）end—group effect （端基效应）entgegen （E,相反之意）energy of activation （活化能）enzyme （酶）ephedrine （麻黃碱）epicatechin （表儿茶素）epicatechin gallate（表儿茶素没食子酸酯）epigallocatechin （表没食子儿茶素）epigallocatechin gallate （表没食子儿茶素，没食子酸酯）epimer （差向异构体）epoxidation （环氧化反应）equatorial bond（平伏键，e 键）ergometrine （麦角新碱）ergostenol （麦角笛醇）essential amino acid （必需氨基酸）essential fatty acid（必需脂肪酸）ester （酯）ester辻ication（酯化反应）farnesol （金合欢醇）fatty acid（脂肪酸）Fischer projection formula（费歇尔投影式）flavanol（黃烷醇）flavanone （_.氢黄酮）flavanonol （二氢黃酮醇）flavonoid （黃酮）flavonol （黄酮醇）f ormal in （福尔马林）free radical （自由基）free radical chain reaction （自山基链反应）Freon （氟利昂）Friedel-Crafts reaction （傅瑞德尔一克拉夫兹反应）Frohde reageProhde 试剂）frontier orbital （前线轨道理论）fructose （果糖）fucose （海藻糖）furan （咲喃）fused ring carbon constitution （稠环碳架）F.Wohler （武勒）galactose （半乳糖）Gabreil reaction （盖布瑞尔合成法）gallocatechin （没食子儿茶素）gallocatechin gallate （没食子儿茶素没食子酸酯）Ga11ermann-Koch reaction （盖特曼一科希反应）geometricalisomer （儿何异构体）germacrone （杜鹃酮）glucose （葡萄糖）glutamic acid （谷氨酸）glutamine （谷酰胺）glycerol （甘油）glycocholic acid （甘氨胆酸）glycogen （糖原）glycoside （糖昔）glycyrrhizic acid （甘草酸）g 1 y c yr rhe t i n i c ac i d （甘草次酸）Gmelin （哥美林）green tea polyphenols （绿茶多酚）Grignard Reaction （格氏反应）Grignard Reagent （格林那试剂，格氏试剂）G.Schiemann reac tion （希曼反应）guaiazulene （愈创木奥）guanidine （K）guan i di no （）1瓜基）guanine （鸟卩票吟）guanyl （眯基）haloform （卤仿）halogenation （卤代反应）halogenation reaction （卤化反应）Haworth （哈沃斯）heat of hydrogenation （氢化热）学疏专业班级学号heat of reaction （反应热）hemiacetal （半缩醛）hesperetin （橙皮素）Hinsberg reaction （兴斯堡反应）histidine （组氨酸）H.Kolbe （科尔贝）Hoffmann degradation （霍夫曼降解反应）Hoffmann elimination （霍夫曼消除）Hoffmann exhaustive methylation （霍夫曼彻底屮基化反应）HOMO （Highest Occupied Molecnlar Orbital,最高被占用分子轨道）homolog （同系物）homologous series （同系列）hormone （激素）HUckel rule （休克尔规则）hybrid orbital （杂化轨道）hydroboration （硼氢化反应）hydrocortisone （氢化可的松）hydrogen bond （氢键）hydrolysis （水解）hyoscyamine （產若碱）hyper con jugat i on effect （超共辄效应）imidazole （咪醴）inclusion compound （包含物）indole （口引嗥）inductive effect （诱导效应）infrared spectroscopy （红夕卜光谱）insulin （胰岛素）invert sugar （转化糖）iodine number （碘值）tectoridin （莺尾学疏专业班级学号昔）isoelectric point （PI,等电点）isoflavanone （〔氢异黃酮）isoflavone （异黄酮）isolated diene （隔离：烯桂）isoleucine （异亮氨酸）isoliquiri tigenin（异甘草素）isomer （同分异构体）isoquinoline （异卩奎卩林）isorhamnetin （异鼠李素）isorhynchophylline （异钩藤碱）isothiazole （异嚏醴）isoxazole （异噁醴）Jones reagent （琼斯试剂）ketal （缩酮）ketone （酮）K. fries rearrangement （傅瑞斯重排）K. Fukui （福井谦一）Knoevenagel reaction （克脑文盖尔反应）Kolbe-Schmidt reaction （柯尔柏-施密特反应）Kutchcrov reaction （库切洛夫反应）lactose （乳糖）lecithin（卵磷脂）leptosidin （莱普西汀）leucine （壳氨酸）leucocyanidin （无色矢车菊素）limonene （苧烯）Lindlar （林德拉）liquiritin （甘草昔）lithium methide （甲基锂）lobeline （山梗菜碱）Lucas reagent （卢卡斯试剂）LUMO （Lowest Unoccupied Molecular Orbita 1）最低空余分子轨道lupinine （羽扇豆碱）lycopene （番茄红素）lycopodine （石松碱）lysine （赖氨酸）maackiain （高丽槐素）Macquis reagent （Macquis 试剂）macrophylline （大叶千里光碱）magnesium acetate reaction （酉昔酸镁反应）magnetic field scan （磁场扫描）malonyl urea（丙二酰SR）maltose （麦芽糖）Mannich reaction （满尼希反应）mannose （甘露糖）mass spectroscopy （质谱）matrine （苦参碱）M. Besthelot （佰赛儒）Mclafferty （麦可拉费蒂重排）（-）-melacacidin ［（-）黑金合欢素］menthol （薄荷醇）学疏专业班级学号（）-menthol ［（）-薄荷醇］menthone （薄荷酮）mesomer （内消旋体）methionine （蛋氨酸）methylporgestin （屮孕酮）provera （¥ 孕酮）methyl testosterone （屮基睾丸素）molecular orbital （分子轨道）molecular orbital theory （分子轨道理论）monoanthracene nucleus （单蔥核）monocrotaline （一野白合碱）monomer （单体）monoterpenoids （单菇）monosaccharide （单糖）morphine （吗啡）mutarotation （变旋光现象）naphthalene （荼）narcotine （那可汀）natrium amalgam reaction （钠汞齐反应）（）-neomenthol ［（）-新薄荷醇］nerol （橙花醇）Newman projection （纽曼投影式）Newman projection formula（纽曼投影式）Nicol prism（尼科尔棱镜）nicotine （烟碱）ninhydrin （E 卩三酮）nitration （硝化反应）nitro compound （硝基化合物）nonaromatic compound （非芳香性化合物）nonbenzenoid hydrocarbon （非苯芳绘）nuclear magnetic resonance spectroscopy （核磁共振谱）nucleic acid（核酸）nucleophilic addition（亲核加成反应）nucleophilic reagent （亲核试剂）nucleoside （核昔）nucleotide （核昔酸）ocimene （罗勒烯）oligosaccharide （寡糖）frontier orbital （前线轨道理论）Oppenaner oxidizing reaction （欧芬脑尔氧化）optical isomer （旋光异构体）optical rotation instrument （旋光仪）organometallic compound （有机金属化合物）organometallics （金属有机化合物）orientation rule （定位规则）oxanthrano 1 （氧化恿酚）oxazole （噁醴）oxidation number （氧化值）oxidation state （氧化态）oxonium salt 盐）oxymatrine （氧化苦参碱）palmatine （巴马汀）papaverine （罂粟碱）paraffin （烷桂）pelargonidin （天竺葵素）peptide （肽）peptide bond （肽键）peptide linkage（肽键）pericyclic reaction （周环反应）Perkin reaction （柏金反应）permeation （透析法）peroxide （过氧化物）peroxide effect （过氧化物效应）phellamurin （黃柏素-7-0-葡萄糖昔）phenanthrene （菲）phenylalanine （苯丙氨酸）phosphorus ylide （麟叶立徳）phylloxanthin （叶黄素）physostigmine （毒扁豆碱）pinacol （频哪醇）pinene （菰烯）piperine （胡椒碱）plane polarized light （平面偏振光）polycyclic aromatic hydrocarbon （多环芳绘）polymer （聚合物）polynuclear aromatic compound （稠环芳绘）polypeptide （多肽）polyreaction （聚合反应）polysaccharide （多糖）polytetrafluroethyleney （泰氟隆）unsaturated fatty acid（不饱和脂肪酸）precipitation （沉淀法）primary structure （一级结构）proanthocyanidin （原花色素）progesterone （黃体酮）protein （蛋白质）pseudoephedrine （伪麻黄碱）pteridine （蝶唳）purine （卩票吟）pyran （毗喃）pyrazine （毗嗪）pyrazole （毗醴）pyridazine （哒嗪）pyridine （毗唏）pyrimidine （喘唳）pyrrole （毗咯）quaternary structure （四级结构）quercetin （榆I皮素）quinine （奎宁）quinoline （卩奎咻）quinones （醍）racemic mixture （外消旋体）racemization （外消旋化）rancidity （酸败）Raney Ni （兰尼線）reaction mechanism （反应历程）Reimer-Tiemann react ion （瑞穆尔一蒂曼反应）reserpine （利血平）residue （残基）resonance energy （共振能）resonance hybrid （共振杂化体）resonance theory （共振论）resonating structure （共振结构式）resveratrol （白藜芦醇）R. B. Woodward （伍徳沃德）rhe in （大黄酸）R. Hoffmann （霍夫曼）rhynchophylline （钩藤碱）ribonucleic acid（核糖核酸）ribose （核糖）rotation （旋光度）rutin （芦丁）saccharide （糖类）Sandmeyer-Gattermann reaction （桑得迈尔一盖特曼反应）Sandmeyer reaction （桑得迈尔反应）saponification （皂化）saponification number （皂化值）Sarrett reagent （沙瑞特试剂）Sawhares projection （萨哈斯投影式）sawhorse projection formula（锯架式）Schiff* s base（西佛碱）secondary structure （二级结构）securinine （一叶萩碱）sennoside A、B、C、D （番泻昔A、B、C、D） serine（丝氨酸）sesquiterpenoids （倍半SS）sigmatropic reaction （ o 键迁移反应）silane （硅烷）single bond（单键）sinoacutine （清风藤碱）B—sitosterol （B一谷縉醇）skyrin （天精，酉昆茜素）S x（NucleophMie substitution）（亲核取代）S X1 （单分子亲核取代反应）S、・2 （双分子亲核取代反sodium borohydride reaction （四氢硼钠反应）sparteine （金雀花碱）specific rotation （比旋光度）sphingomyelin （鞘磷脂）spiro hydrocarbon （螺环坯）squalene （鲨烯）stachydrine （水苏碱）starch （淀粉）stereochemistry （立体化学）stereoisomer （立体异构）stereocpecificity （立体专一性）steroidal compound （笛体化合物）Stevens rearrangement （史蒂文斯重排）stigmastane （豆當烷）strychnine （士的F）sucrose （蔗糖）sulfonation （磺化反应）systematic nomenclature （系统命需法）taurocholic acid （牛磺胆酸）tautomer （互变异构体）tautomerism （互变异构现象）taxifolin （黄杉素）tea polyphenols （茶多酚）Teflon （泰氟隆）terpenoid （祜类化合物）tertiary structure （三级结构）testosterone （睾丸素）tetrahydropalmatine （延胡索乙素，四氢巴马汀）tetramethyl silane （四甲基硅烷）tetraterpenoid （四菇类）thiazole （噬醴）thiophene （卩塞吩）threonine （苏氨酸）torsional energy （扭转能）torsional strain （扭转张力）transition sate （过渡态）triglyceride （甘油三酯）trimethyl aluminium （三屮基铝）triptolide （雷公藤甲素）triterpenoid （三菇类）tryptophan （色氨酸）tylophorinine （娃儿藤定碱）tyrosine （酪氨酸）uridine （尿喀唏）urea （服）urotropine （乌洛托品）valence bond method （价键学说）valine （織氨酸）visible-ultraviolet spectroscopy （可见一紫外光谱）vitamin A（维生素A）vitamin B-（维生素BQWilkinson （威尔克森）Williamson synthesis （威廉森合成法）Wittig reaction (维蒂希反应)zingiberene (姜烯)Zusammen (Z,德文，在一起之意)中英对照A.J 反应历程(A J reaction mechanism )卩丫唳(acridine)埃姆德降解(Emde degradation)安息香缩合反应(benzoic condensation reaction) 氨基酸(amino acid)-氨基J 酸(-aminobutyric acid)氨解(ammonolysis)胺(amines)(azulene)B AC2反应历程(B AC2 reaction mechanism )巴比妥(barbital)巴马汀(palmatine)白藜芦醇(resveratrol)拜耳(Baeyer)佰赛儒(M. Besthelot)半缩醛(semiacetal )半胱氨酸(cysteine)半乳糖(galactose)包含物(inclusion compound)苯丙氨酸(phenylalanine)苯(benzene)苯甲酸(benzoic acid)班级学院苯二中酸(benzene dicarboxylic acid)苯并咪醴(benzimidazole)苯并U塞醴(benzothiazole)倍半?E (sesqui terpenoid)比旋光度(specific rotation)必需氨基酸(essential amino acid)变性(denature)变旋光现象(mutarotation)表儿茶素(epicatechin)表儿茶素没食子酸酯(epicatechin gallate)表没食子儿茶素(epigallocatechin)表没食子儿茶素没食子酸酯(epigallocatechin gallate) 表面活性剂(surface active agent )槟榔碱(arecoline)丙氨酸(alanine)丙氨酸乙硫酯(ethyl alanine sulfide)丙二酰服(malonyl urea)伯察留史(Berzelius)柏金(Perkin)反应薄荷醇(menthol)()一薄荷醇(()一menthol)薄荷酮(menthone)布特力洛夫(Bytrepob)布朗反应(Braun reaction)残基(residue)草酸(oxalic acid)超共辘效应(hyperconjugation effect)差向异构体(epimer)查尔酮(chaicone)茶多酚(tea polyphenols)B -常山碱(B -dichroine)沉淀法(precipitation)橙皮素(hesperetin)橙花醇(nerol)稠环芳坯(polynuclear aromatic compound) 稠环碳架(fused ring carbon constitution) 醇钠(sodium alcohols)醇解(alcoholysis)穿心莲内酯(andrographo 1 i de)磁场扫描(magnetic field scan)B —雌二醇(B —dihydrotheelin)酉昔酸镁反应(magnesium acetate reaction ) 萃取法(extraction) DDQ (2, 3—二氯一5, 6—氛基一1, 4 —苯酉昆)大黃素型(emodin-type)大黄酸(rhein)大豆黄素(daidzein)大叶千里光碱(macrophyll ine)达尔森(Darzen)反应哒嗪(pyridazine)单键(single bond)单体(monomer)单蔥核(monoanthracene nucleus)单菇(monot erpeno i ds)单糖(monosaccha:ride)单线态(singlet)蛋氨酸(methionine)蛋白质(protein)胆當烷(cholestane)胆笛醇(cholesterol)胆笛酸(cholalic acid) 胆笛烷(cholestane) 胆笛醇(cholesterol)党参碱(codonopsine)等电点(isoelectric point , PI) 迪克曼反应(Dieckmann reaction ) 狄尔斯一阿尔德(Diels-Alher) 电场扫描(electric field scan) 电性效应(electromeric effect) 电荷转移络合物(charge-transfer complex) 碘仿试验(iodoform test) 碘值(iodine number )淀粉(starch)敌敌畏(dichlorovos)蝶唳(pteridine)丁烯二酸(butene dioic acid) 定位规则(orient at iong rule) 动力学概念(dynamical concept) 豆笛烷(stigmastane) 毒芹碱(coniine) 毒扁豆碱(physostigmine) 杜鹃酮(germacrone) 端基效应(end—group effect) 对映异构(enantiomerism) 对映体(enantiomers) 对氨基苯磺酰胺(sulfanilamide) 多环芳桂(polycyclic aromatic hydrocarbon)多糖(polysaccharide)多肽(polypeptide)多磷酸酯(polyphosphate ester)E (entgegen,德文，相反之意)EAN 规则(EAN rule)莪术醇(curcumenol)鹅去氧胆酸(chemocholic acid)噁醴(oxazole)蔥(anthracene)蔥酚(anthrol)蔥I® (anthraquinones)蔥酮(anthrone)9-蔥酮大黃酚(chrysophanol 9-anthrone)儿茶素(catechin)〔烯桂(diene)〔氯卡宾(dichlorocarbene)—.屮亚飒(dimethyl sulfoxide)—•硫基丙醇(dimercaptopropanol )：级结构(secondary structure):氢黃酮(flavanone)—.氢黃酮醇(flavanonol)"•氢异黄酮(isoflavanone)二氢查尔酮(dihydrochalcone)二桔类(diterpenoids)番泻昔A、B、C、D(sennoside A、B、C、D) 番茄红素(lycopene)反芳香性化合物(antiaromatic compound)反应历程(reaction mechanism)反应热(heat of reaction)芳香绘(aromatic hydrocarbon)芳香性(aromaticity)芳香性化合物(aroniatic compound)芳构化(aromatization)放氮反应(denitr辻ication)E 燕草素(delphinidin)非芳香性化合物(nonaromatic compound)非离子表面活性剂(nonionic)非对映体(diasteroisomer)非质子性溶剂(nonprotonic solvent )非苯芳坯(nonbenzenoid hydrocarbon)菲(phenanthrene)斐林溶液(Fehting solution )费歇尔(E. Fischer)费歇尔投影式(Fischer projection formula)分子轨道(molecular orbital)分子轨道对称性守恒理论(conservation of orbital symmetry theory)分子轨道理论(molecular orbital theory)酚节明(Phenoxybenzamine)芬克尔斯坦(Finkelstein)芬氟拉明(fenfluramine)粪笛烷(coprostane)氟芬那酸(flufenamic Acid)福井谦一(K. Fukui)傅-克反应(Friedel-Crafts alkylation reaction)傅瑞斯重排(K. fries rearrangement)傅瑞德-克拉天茨反应(Friedel-Crafts reaction)辅酶Qw( coenzyme Q10)咲喃(furan)盖布瑞尔合成法(Gabreil reaction)盖特曼一科希(Gattermann-Koch)反应甘露糖(mannose)甘氨酸(glycine)甘油(glycerol)甘氨胆酸(glycocholic acid)甘草酸(glycyrrhizic acid)甘草次酸(glycyrrhetinic acid)甘草昔(liquiritin)高丽槐素(maackiain)睾丸素(testosterone)隔离—.烯桂(isolated diene) 格林那试剂(Grignard reagent) 哥美林(Gmelin)共振能(resonance energy)共振论(resonance theory) 共振杂化体(resonance hybrid) 共振结构式(resonating structure) 共轨效应(conjugative effect) 共辄体系(conjugation system) 共辄二烯烧(conjugated diene) 构象(conformation)构象异构(conformational isomerism) 构造异构(constitutional isomerism) 构型保持(configuration conservation) 构型转化(configuration inversion) 钩藤碱(rhynchophyll ine)B —谷笛醇(B —sitosterol)谷氨酸(glutamic acid)谷酰胺(glutamine)古柏尔(A. Couper)古柯碱(cocaine)M(guanidine )寡糖(o 1 igasaccharide)冠瞇(crown ether)光学异构体(optical isomer)硅烷(silane)硅油(silicon oil)过氧化物(peroxide)过氧化物效应(peroxide effect)过渡态(transition state)果糖(fructose)哈沃斯(Haworth)海藻糖(fucose)核磁共振谱(nuclear magnetic resonance spectroscopy) 核昔酸(nucleotide)核甘(nucleoside)核酸(nucleic acid)核糖(ribose)(~) -黑金合欢素[(-)melacacidin)]红古豆碱(cuskohygrine)红花昔(carthamin)红夕卜光谱(infrared spectroscopy)互变异构现象(tautomerism)互变异构体(tautomer)胡萝卜素(carotene)胡椒碱(piperine)榊皮素(quercetin)化学键(chemical bond)花色素(anthocyanidin)环坯(cyclic hydrocarbon)环氧化反应(epoxidation)环力口成反应(cycloaddition recation)环状碳架(cyclic carbon constitution)环己—•酮(cyclic hexanedione)环糊精(cyclodextrin)a , B —环氧酸酯(a , B —cycloxacid ester)黄柏素-7-0-葡萄糖昔(phellamurin)黄苓素(baicalein)黄苓昔(baicalin)黃杉素(tax辻olin)黄酮(flavonoid)黃酮醇(flavonol)黃烷醇(flavanol)黃体酮(progesterone)磺胺(sulfan 订amide)磺化反应(sulfonation)活化能(energy of activation)霍夫曼(R. Hofmann)霍夫曼降解反应(Hoffmann degradation)霍夫曼消除(Hoffmann elimination)霍夫曼彻底甲基化反应(Hoffmann exhaustive methylation) 儿何异构体(geometrical isomer)己二胺(hexanediamine)(quaternary ammonium salt)W (quaternnary ammonium hydrate )季丿憐盐(quaternary phosphonium salt )激素(hormone)中孕酮(methporgestin)屮基睾丸素(methyl testosterone)屮基锂(lithium methide)甲壳质(chitin)价键学说(valence bond method)假酸式(pseudo-acid form )O 键(o bond)o 键迁移反应(sigma tropic reaction)兀键(Ji bond)碱基配对规律(base pairing rule)姜烯(zingiberene)胶束(micelle)交义醇醛缩合反应(crossed aldol reaction)金合欢醇(farnesol)金属有机化合物(metalloorganic compound)金雀花碱(sparteine)金鸡宇(cinchonine)金刚烷胺(symmetrel)紧密离子对(tightness ionpair )精氨酸(arginine)竞争反应(competing reaction )聚合物(polymer)聚合反应(polyreaction)聚集二烯桂(cumulative diene)锯架式(andiron formula ; sawhorse projection formula) 卡宾(碳烯)(Carbene)开息纳尔一武尔夫(Kishner-WoIff)—黃鸣龙法凯库勒(A. Kekule) 康尼查罗(Cannizzaro )反应科尔贝(H・Kolbe)科瑞一郝思反应(E.J.Cory—H. House reaction) 可的松(cortisone) 可见一紫外光谱(visible-ultraviolet spectroscopy)克莱森一斯密特(Claisen-Schmidt)反应克脑文盖尔(Knoevenagel)反应克莱门森(Clemmensen)还原反应克莱森重排(Claisen rearrangement)克莱森缩合反应(Claisen condensation reaction ) 柯尔柏-施密特反应(Kolbe-schmidt reaction) 柯亚素(chrysarobin)壳糖胺(chitos&mine)苦参碱(matrine)库切洛夫反应(Kutchcrov reaction)奎宇(quinine)卩奎卩林(quinoline)酉昆(quinones)醍氢酿(quinhydrone)莱普西汀(leptosidin)赖氨酸(lysine)兰尼银(Raney Ni )奁君碱(hyoscyamine)雷公藤屮素(triptolide)利血平(reserpine)立体选择性(stereoselective)立体专一性(stereospecific)立体异构(stereoisomer)离域(delocalization)离域能(delocalization energy ;delocalized energy) 离域电子(delocalized electron)离去基团(leaving group )链引发阶段(chain initiation step)链增长阶段(chain propagation step)链终止阶段(chain termination step) 链状碳架(chain carbon constitution) 亮氨酸(leucine)林德拉(Lindlar)麟叶立德(phosphorus ylide)0葬(phosphureted hydrogen)錢盐(phosphorate)麟酸(phosphonic acid )硫W(thiourea )硫醇(thioalcohol )硫® (thioether )硫酚(phenylsulfhydryl )留氮反应(reaction of nitrogen retention)龙脑(borneol)卤代反应(halogenation)卤仿(haloform)卤仿反应(haloform reaction )卢卡斯试剂(Lucas reagent)芦荟大黄素(aloe-emodin)芦丁(rutin)ci —卵磷脂(ci —lecithine )轮烯(annulene)酪氨酸(tyrosine)罗勒烯(ocimene)罗森孟德(Rosenmund)还原法螺环绘(spiro hydrocarbon)班级学院氯乙酸屮酯(methyl chloroacetate) (chloro acetyl formate) 绿茶多酚(green tea polyphenols)马尔可夫尼可夫(Markovnikov)规则麻黄碱(ephedrine)吗啡(morphine)麦可拉费蒂(Mclafferty)麦芽糖(maltose)麦角笛醇(ergostenol)麦角新碱(ergometrine)麦克尔加成(Michael addition)满尼希(Mannich)反应梅尔外英一彭多夫(Meerwein-Poundorf)还原反应酶(enzyme)没食子儿茶素(gallocatechin)没食子儿茶素没食子酸酯(gallocatechin gallate)眯基(amidino)喘唳(pyrimidine)咪卩坐(imidazole)那可汀(narcotine)钠汞齐反应(natrium amalgam reaction)蔡(naphthalene)脑磷脂(cephalin)内消旋体(meso —form)尼科尔棱镜(Nicol prism)服(尿素)(urea)鸟嚓吟(guanine)尿喘唳(uracil)柠檬醛(citral)苧烯(limonene)牛磺胆酸(taurocholic acid)纽曼投影式(Newmans projection formular)扭转能(torsional energy)扭转张力(torsional strain)欧芬脑尔氧化反应(Oppenaner oxidizing reaction) 偶氮基(azo) 偶合(偶联)反应(coupling reaction)偶合组分(或偶合剂)(coupling agent )偶极-离子键(dipolar-ionic bond )浪烯(pinene)硼氢化反应(hydroboration)硼氢化钠("BHJ毗哆醛(pyridoxal)毗咯(pyrrole)毗喃(pyran)毗嗪(pyrazine)毗醴(pyrazole)毗唳(pyridine)嚓吟(purine)频哪醇(pinacol)平面偏振光(plane polarized light)平伏键(e 键,equatorial bonds)苹果多酚(apple polyphenols)普鲁卡因(procaine )葡萄糖(glucose)歧化反应(disproportionation reaction )前列腺素(prostaglandin)前线轨道(frontier orbital)理论茜草素(alizarin)茜素型(alizarin-type)强心昔(cardiac glycosides)疑月亏酸(hydroximic acid )B —羟基醛(B —hydroxy aldehyde )桥环绘(bridged hydrocarbon)鞘磷脂(sphingomyelinicacid)亲电性试剂(electrophile)亲电加成反应(electrophilic addition)亲电取代(electrophilic substitution)亲核试剂(nucleophilic reagent)亲核加成反应(nucleoph订ic addition)亲核取代(nucleophilic substitution)亲核取代反应历程(nucleophilic substitution reavtion mechanism) 亲双烯体(dienophile)芹菜素(apigenin)氢解(hydrogenolysis)氢化苯基锡(hydrogenation benztin)氢化正丁基锡(hydrogenation butyltin )氢化油(hydrogenated oil )氢化可的松(hydrocort i sone)氢化热(heat of hydrogenation)氢屮酰化法(hydroformylation)氢键(hydrogen bond)清风藤碱(sinoacutine)琼斯试剂(Jones reagent)块桂(alkyne)热力学概念(thermodynamic conception )溶剂化效应(solvating effect)乳糖(lactose)瑞穆尔-蒂曼反应(Reamer-Timann reaction)萨哈斯投影式(Sawhares projection)卩塞吩(thiophene)嚏醴(thiazole)三菇(triterpenoids)三屮基铝(trimethyl aluminium)三级结构(tertiary structure)三线态(triplet state)三苯基麟(triphenyl phosphine)三磷酸腺昔(adenosine triphosphate)桑得迈尔反应(Sandmeyer reaction)桑得迈尔一盖特曼反应(Sandmeyer-Gattermann reaction) 色氨酸(tryptophan)色谱法(chromatography)沙瑞特试剂(Sarrett reagent)鲨烯(squalene)山油柑碱(acronyc ine)山扁豆双覘(cassiamine)山梗菜碱(lobeline)肾上腺皮质激素(adrenal cortex hormone)生物甲基化(biological methylate)18 电子规则(18- electron rule)史蒂文斯重排(Stevens rearrangement)石松碱(lycopodine)士的F (strychnine)矢车菊素(cyanidin)手性(chirality)水苏碱(stachydrine)双蔥核(bi-anthracene nucleus)双烯体(diene)J顺反异构(cistrans isomerism)顺反异构体(cis-trans isomer)四氢巴马汀(tetrahydropalmatine)四级结构(quaternary structure)四氢硼钠反应(sodium borohydride reaction) 四菇(quadruterpene)四屮基硅烷(tetramethylsilane)丝氨酸(serine)松香酸(abietic acid)苏氨酸(threonine)酸败(rancidity )缩醛(acetal)缩二腺反应(biuret reaction)肽(peptide)肽键(peptide bond)碳水化合物(carbohydrate)碳酰氯(carbonyl chloride :phosgene )糖类(saccharide)糖昔(glycoside)糖原(glycogen)天冬氨酸(aspartic acid)天精(skyrin)天竺葵素(pelargonidin)SE 类化合物(terpenoids)同系列(homologous series)同系物(homolog)同分异构体(isomer)酮(ketone)透析法(permeation)1- 吐根碱(1-emetine)脱竣反应(decarboxylic reaction)娃儿藤定碱(tylophorinine)瓦尔登转化(Walden inversion)外消旋体(racemic mixture)外消旋化(racemization)烷绘(alkane)维生素A (vitamin A)维生素By (vitamin B1：)维生素Ki、K: (vitamin K】、K2 )维蒂希反应(Wittig reaction)伪麻黃碱(pseudoephedrine)威尔克森(wilkinson)威廉森合成法(W订liamson synthesis)武勒(F. Wohler)无色矢车菊素(leucocyanidin)伍德沃德(R. B. Woodward)武兹反应(A. Wurtz reaction)烯怪(alkene)系统命名法(systematic nomenclature)西佛碱(Schiff ' s base)希夫(schiff)试剂吸电子共轨效应(electronwithdrawing conjugative effect) 喜树碱(camptothecine)西佛碱(schiff base)希曼反应(G・ Schiemann reaction)纤维二糖(cellobiose)纤维素(cellulose)腺U票吟(adenine)硝化反应(nitration)消除反应(elimination reaction)小漿碱(berberine)硝基化合物(nitro compounds)协同反应(concerted reaction)織氨酸(valine)()—新薄荷醇［()—neomentholJ兴斯堡反应(Hinsberg reaction)胸腺唏唳(thymine) 12-15休克尔规则(HUckel rule)比旋光度(specific rotatory power)旋光仪(optical rotation instrument)旋光异构体(optical isomer)血红素(haemachrome )亚硝酸(nitrous acid)烟碱(nicotine)延胡索乙素(tetrahydropalmatine)盐酸-镁粉反应(HCl-Mg powder reaction)盐酸-锌粉反应(HCl-Zn powder reaction)徉. 盐(oxonium salt)氧化苦参碱(oxymatrine)氧化蔥酚(oxanthranol)氧化态(oxidation state)氧化值(oxidation number)阳离子表面活性剂(cationic surface active agent)叶黄素(phylloxanthin)叶绿素(chlorophyll)一叶萩碱(securinine)—野白合碱(monocrotaline)一级结构(primary structure)乙硼烷(diborane)1 —乙烘基环戊醇(1 —ethynyl cyclopentanol )乙二胺(ethylene diamine)乙烯酮(ethenone ; ketene )乙酸(acetic acid)乙二酸(ethanedioic acid )异kT草素(isoliquiritigenin)异黄酮(isoflavone)异鼠李素(isorhamnetin)异钩藤碱(i s orhynchophy lline)异亮氨酸(isoleucine)异头物(anomer)异头效应(anomeric effect)异噁醴(isoxazole)异嚏醴(isothiazole)异月青(月卡)(isonitrile)异唾咻(isoquinoline)胰岛素(insulin)阴离子表面活性剂(anionic surface active agent)即三酮(ninhydrin )“引口朵(indole)罂粟碱(papaverine)油脂(axunge； grease； lipin；)有效原子序数(effective atomic number)有机金属化合物(organometallic compound)有机锂(organic-Li) (organic lithium ) (organolithium compound) 诱导效应(inductive effect)羽扇豆碱(lupinine)愈创木奥(guaiazulene)原花色素(proanthocyanidin)莺尾昔(iridin)原子轨道(atomic orbital)Z (Zusammen,德文，在一起之意)杂化轨道(hybrid orbital)杂环碳架(heterocycle carbon constitution)笛体化合物(steroidal compound)皂化反应(sapon辻ication reaction)皂化值(s&pon辻ication value)扎依采夫(Saytzeff)规则樟柳碱(anisodine)樟脑(camphor)蔗糖(sucrose)-折叠(beta-pleated sheet)蒸镭法(distillation)质谱(mass spectroscopy)质子性溶剂(protonic solvent)月旨环桂(alicyclic hydrocarbon： cycloalkane) 直立键(a 键,axial bond)重氮化反应(diazotization reaction)重氮盐(diazonium salt)重氮组分(diazocomponent)重氮中烷(diazomethane)周环反应(pericyclic reaction)转化糖(invert sugar)自由基(free radical)自山基链反应(free radical chain reaction)B —紫罗兰酮(P — ionone )组氨酸(histidine)。
Ganoderic acid T from Ganoderma lucidum mycelia induces mitochondria mediated apoptosis
Ganoderic acid T from Ganoderma lucidum mycelia induces mitochondriamediated apoptosis in lung cancer cellsWen Tang a ,Jian-Wen Liu a,⁎,Wei-Ming Zhao b ,Dong-Zhi Wei a ,Jian-Jiang Zhong a,c,⁎aState Key Laboratory of Bioreactor Engineering,East China University of Science and Technology,130Meilong Road,Shanghai 200237,ChinabDepartment of Natural Products Chemistry,Shanghai Institute of Materia Medica,Shanghai Institutes for Biological Sciences,Chinese Academy of Sciences,Shanghai 201203,ChinacKey Laboratory of Microbial Metabolism,Ministry of Education,College of Life Science &Biotechnology,Shanghai Jiao Tong University,800Dong-Chuan Road,Minhang,Shanghai 200240,ChinaReceived 7June 2006;accepted 4September 2006AbstractGanoderma lucidum is a well-known traditional Chinese medicinal herb containing many bioactive compounds.Ganoderic acid T (GA-T),which is a lanostane triterpenoid purified from methanol extract of G.lucidum mycelia,was found to exert cytotoxicity on various human carcinoma cell lines in a dose-dependent manner,while it was less toxic to normal human cell lines.Animal experiments in vivo also showed that GA-T suppressed the growth of human solid tumor in athymic mice.It markedly inhibited the proliferation of a highly metastatic lung cancer cell line (95-D)by apoptosis induction and cell cycle arrest at G 1phase.Moreover,reduction of mitochondria membrane potential (Δψm )and release of cytochrome c were observed during the induced apoptosis.Our data further indicate that the expression of proteins p53and Bax in 95-D cells was increased in a time-dependent manner,whereas the expression of Bcl-2was not significantly changed;thus the ratio of Bcl-2/Bax was decreased.The results show that the apoptosis induction of GA-T was mediated by mitochondrial dysfunctions.Furthermore,stimulation of the activity of caspase-3but not caspase-8was observed during apoptosis.The experiments using inhibitors of caspases (Z-VAD-FMK,Z-DEVD-FMK and Z-IETD-FMK)confirmed that caspase-3was involved in the apoptosis.All our findings demonstrate that GA-T induced apoptosis of metastatic lung tumor cells through intrinsic pathway related to mitochondrial dysfunction and p53expression,and it may be a potentially useful chemotherapeutic agent.©2006Elsevier Inc.All rights reserved.Keywords:Ganoderma lucidum ;Ganoderic acid;Apoptosis;Caspases;Lung tumor cellsIntroductionGanoderma lucidum (Fr.)Karst (Polyporaceae)is an important traditional Chinese medicinal mushroom used for several thousand years in China,Japan,and other countries.Evidence has accumulated concerning the medicinal application of ganoderma in the treatment of various diseases,such as cancers and immunological disorders,and in recent years the biotechnological utilization of the mushroom has been very popular (Zhong and Tang,2004).It is well documented that the natural mixtures of triterpe-noids in G.lucidum inhibit proliferation of human and mouse carcinoma cell lines (Liu et al.,2002;Sliva,2003,2004).The cytotoxicity of extract of triterpene-enriched Ganoderma tsugae was claimed to be mediated through apoptosis and cell cycle arrest in MCF-7human breast,prostate cancer cells and PC-3cells (Gao and Zhou,2003;Jiang et al.,2004).Other studies have shown that apoptosis induced by triterpene-enriched extracts of G.lucidum was brought about through suppressing protein kinase C,activating mitogen-activated protein kinases and G 2-phase cell cycle arrest (Lin et al.,2003);through indu-cing a marked decrease of intracellular calcium level (Zhu et al.,2000);through inducing NAD(P)H:quinone oxidoreductase in cultured hepalcic7murine hepatoma cells (Ha et al.,2000);by activating MAP kinases in rat pheochromocytoma PC12cells (Cheung et al.,2000)or stimulating actin polymerizationinLife Sciences 80(2006)205–211/locate/lifescie⁎Corresponding authors.Zhong is to be contacted at College of Life Science and Biotechnology,SJTU,800Dong-Chuan Road,Shanghai 200240,China.Tel./fax:+862134204831.Liu,Department of Molecular and Cellular Pharmacology,ECUST,Shanghai 200237,China.E-mail addresses:jjzhong@ (J.-J.Zhong),liujian@ (J.-W.Liu).0024-3205/$-see front matter ©2006Elsevier Inc.All rights reserved.doi:10.1016/j.lfs.2006.09.001bladder cancer cells in vitro(Lu et al.,2004).However,it is difficult to identify whether or not the ingredients in extracts (mixtures)have antagonistic or synergistic biological effects, and it is also unclear what compound in extracts is mainly responsible for the bioactivities,which makes the study of structure–activity relationship difficult.Therefore,the use of a purified triterpene is required to reveal the acting mechanism of responsible compounds and to further screen and rationally design structurally similar lead compounds.Until now,there has been a lack of investigation using purified triterpenes to study bioactivity mechanism except for ganoderic acid X(GA-X)(Li et al.,2005).GA-X was shown to induce apoptosis of cancer cells,and the disruption of mito-chondrial membrane,cytosolic release of cytochrome c and activation of caspase-3under its treatment were also reported(Li et al.,2005).However,whether caspase-8and p53was involved in its induced apoptosis is unclear.In this work,the cytotoxicity of ganoderic acid T(GA-T),a triterpenoid purified from bioreactor-cultivated mycelia of ganoderma by our lab(Fig.1)(Tang,2006),to various human carcinoma cell lines was investigated.Furthermore,the growth inhibitory effect of GA-T on95-D cells and molecular events triggered by GA-T in the apoptosis of95-D cells,including the effects on caspase-8and p53,are elucidated.The work is con-sidered useful to the development of interesting chemothera-peutic drugs.Materials and methodsMaterialsRPMI1640and Dulbecco's Modified Eagle Medium (DMEM),trypsin,MTT,PI were obtained from Sigma Chemical Co.(St Louis,MO).Fetal bovine serum(FBS)and antibiotics (penicillin and streptomycin mixture)were purchased from Huanmei Co.(Shanghai,China).Antibodies for actin and p53, Bax,Bcl-2were purchased from BD Biosciences PharMingen, USA.Goat anti-rabbit IgG-conjugated to horseradish peroxidase (HRP)and goat anti-mouse IgG-conjugated to HRP were pur-chased from Biovision(Mountain View,CA).Selective inhibitors of caspase-3(Z-DEVE-FMK),and caspase-8(Z-IETD-FMK) and general caspase inhibitors(Z-V AD-FMK)were purchased from Biovision(Mountain View,CA).Cytochrome c was pur-chased from Sigma(Germany).GA-T was purified with semi-preparative liquid chromatog-raphy in our lab with its purity over99%(Tang,2006).Stock solutions of GA-T were prepared in dimethyl sulfoxide(DMSO) and stored at−20°C.Further dilutions were made with RPMI 1640medium just before use.The final concentration of DMSO was less than0.1%.Cell culturesHuman highly metastatic lung tumor cell line95-D(lung), human liver tumor cell line SMMC7721(liver),human epidermal cancer KB-A-1and KB-3-1(epidermis),human cervixal cancer HeLa(cervix),and human normal cell line HLF(lung)and L-02 (liver)were purchased from the Center of Cell Culture Collection of Academia Sinica(Shanghai,China).All those cell lines were cultured in RPMI1640medium containing10%heat-inactivated fetal bovine serum,100units/ml penicillin,and100μg/ml streptomycin in an atmosphere of5%CO2and95%air at37°C. Cells(1×105/ml)were treated with GA-T at various indicated concentrations and for various periods.In some experiments, before addition of GA-T to the cultures,cells were pre-incubated for60min at37°C with selective caspase inhibitors,i.e.,caspase-3inhibitor,Z-DEVD-FMK,10μM;caspase-8inhibitor,Z-IETD-FMK,10μM;and pan-caspase inhibitor,Z-V AD-FMK,10μM. Cell proliferation assayThe1×105cells/ml were plated in96-well tissue culture plate, and treated with different concentrations of GA-T(0,6,12.5,25 and50μg/ml)after4h.Cells were incubated for another24h for cell proliferation.Viability of cells was evaluated by MTT[3-(4,5-dimethylthiazo l-2-yl)-2,5-diphenyltetrazolium bromide]reduc-tion method.The cells were stained with MTT for4h and then incubated with lysis buffer(20%SDS in50%N,N-dimethylfor-mamide)for another30min.Optical density at570nm was detected for monitoring the cell viability.Effects of the drugs on inhibition of cell growth were calculated,and the cells treated with DMSO at same concentrations as in the drugs used as controls.For colony formation assay,a total of2000cells was resus-pended in RPMI1640medium containing10%FBS and0.35% agar and plated on plates with a solidified bottom layer(0.5% agar in growth medium).The plates were incubated in a humi-dified incubator at37°C.Various concentrations of GA-T were added to cells,and cells were cultured for12days until colonies appeared.Then,cells were fixed and stained with crystal violet and counted.Dose–response curves and the concentration of GA-T inhibiting colony formation by50%(EC50)were obtained. Cell cycle distribution and apoptosis evaluationCell cycle parameters were analyzed by flow cytometry.After induction treatment under50μg/ml,cells were fixed with ethanol and then stained with propidium iodide after removing the RNA in the cells by RNase treatment,and the fluorescence of individual nuclei(about10,000events)was analyzed by flow cytometry (Becton Dickinson FACScan,USA).The percentage of cells in the G1,S and G2–M phases of the cell cycle was determined.Apoptosis was detected by annexin V-FITC binding assay. Normal,apoptotic,and necrotic cells were distinguishedby Fig.1.Structure of ganoderic acid T(GA-T).206W.Tang et al./Life Sciences80(2006)205–211using the annexin V-propidium iodide(PI)kit according to the manufacturer's instructions(Roche Diagnostics,Germany). After washing in PBS buffer,cells were resuspended for10min in the staining solution and analyzed by flow cytometry.The percentages of viable and dead cells were determined with about 10,000cells/sample.Mitochondrial membrane potential analysis(Δψm)Mitochondrial transmembrane potential was analyzed by flow cytometry.Cells under the GA-T treatment were incubated with 50nM3,3′-dihexyloxacarbocyanine iodide(DiOC6)(Molecular Probes,USA)for15min at37°C,and associated fluorescence alterations in95-D cells were evaluated by FACScan flow cytometry(Becton Dickinson and Company,CA,USA).Loss in DiOC6staining indicates an association of the disruption of mitochondrial inner transmembrane potential(Δψm).Cytochrome c(cyt-c)release analysisThe release of cytochrome c was detected with HPLC and ultraviolet(UV)detector.After induction treatment,cells were treated as reported(Appaix et al.,2000;Elliott et al.,2003).Cells (2×106)were rinsed three times with PBS,scraped from the dish and then lysed and centrifuged cells for separation of mito-chondrion(4°C,25,000g,30min).The positive control was that of cells treated with GA-T and the negative control used intact cells without any treatment.Initial spectroscopic measurements were made on a UNICO spectrophotometer(UNICO,Shanghai, China).Chromatography of cytochrome c was performed using a5μm C18reverse-phase column(250×4.6mm)by Shimadzu HPLC system with UV detector(Shimadzu,Japan).The detec-tion wavelength was393nm.A gradient from20%to60%of acetonitrile in water with trifluoroacetic acid(0.1%v/v)over 20min with a flow rate of1.0ml/min was used.Western blotting analysisAfter GA-T treatment,cells were washed and lysed in lysis buffer(1%NP40,20mM Tris(base pH7.4),137mM NaCl,10% glycerol,and1mM phenylmethyl sulfonyl fluoride).Cell lysates cleared of debris and nuclei were resolved on15%SDS gels and transferred to a polyvinylidene difluoride membrane(LOT 1673B22,Solon,OH,USA).After being probed with specific primary antibodies,including incubation with anti-p53,anti-Bax, anti-Bcl-2and anti-actin,the specific protein complex formed on appropriate secondary antibody treatment(1:1000)was identified using the DAB substrate reagent(Pierce,USA).Total cellular protein was determined using the Bradford method.Analysis of caspases activitiesActivity of caspase-8was measured by using caspase colo-rimetric assay kit(Catalog PT3356-1,BD Biosciences,USA). Briefly,cell lysates were mixed with DTT(10mM)-rich reac-tion buffer containing50mM IETD-pNA,caspase-8substrates, and incubated for1h at37°C.Enzyme-catalyzed release of pNA was monitored using a microplate reader at405nm.The activity of caspase-3was detected by luminometer with cas-pase-Glo3assay kit(Catalog G8090,Promega,USA)according to the manufacturer's protocol.As caspase-3and8was assayed by using respective specific substrate Ac-DEVD-pNA and Ac-IETD-pNA,the cross-reaction activity was avoided.Animal experimentsFour-week old male BALB/c mice were purchased from SLAC Laboratory Animal Co.Ltd.(Shanghai,China).Specific-pathogen-free(SPF)status was verified by the supplier.Mice were maintained in isolation rooms in filter top cages.The light cycle in the rooms was12h daily,the room temperature was at 22±1.1°C and the room humidity was in the range of40–70%. All mice were fed autoclaved mouse feed and autoclaved water.The animals were implanted with1×108cells/ml of95-D in 0.1ml at two flanks per mouse.Tumor growth was examined twice a week after implantation.The solid tumors were collected after being allowed to develop for3weeks and cut as cube of 0.1×0.1×0.1cm,and then implanted into other mice at two flanks per mouse.The xenograft tumor-bearing nude mice were divided randomly into4groups,and each group includes6mice.When the size of solid tumor in tumor-bearing nude mice reached100mm3,the tumor-bearing nude mice were treated with GA-T via celiac injection at the dosage of0,12.5and 25mg/kg for12days,and then observed for another conse-cutive8days.The control group was treated with vehicle mixture only.At the end of the experiments,animals were euthanized with carbon dioxide inhalation,followed by cervical dislocation,and then the solid tumors were picked up.Data were statistically analyzed by solid tumor weight.The rate of inhibition(IR)was calculated according to the formula:IR=[(mean tumor weight of the experimental group−mean tumor weight of the control group)/mean tumor weight of the control group]×100%.Statistical analysisAll experiments were done at least three different times(n=3) unless otherwise indicated.Data are expressed as means±S.D., and significance was assessed by t test.Differences with P b0.05 (⁎),P b0.01(⁎⁎),P b0.001(⁎⁎⁎)were considered significantly different.ResultsGA-T inhibits proliferation of various cancer cells and affects the viability of metastatic lung carcinoma cells by inducing apoptosis and cell cycle arrestWe first investigated the effect of GA-T on proliferation of human cancer cells and normal cells.The results in Fig.2indicate that GA-T caused a decrease in proliferation of some cancer cells. It had higher cytotoxicity to95-D cell line than to normal cell lines.But the effects of GA-T on SMMC-7721and HLF are similar.This indicates that GA-T had different cytotoxic potency207W.Tang et al./Life Sciences80(2006)205–211against different tumor cells,which is also generally observed for other drugs.As shown in Fig.3A,the viability of 95-D cells was suppressed 70%at 50μg/ml at 24h by GA-T.The growth inhibition was exerted in a dose-dependent manner within the indicated concentrations.Its IC 50was estimated to be 27.9μg/ml.At the same time,GA-Tat a low concentration could also strongly inhibit the formation of cell colony of 95-D (Fig.3B).The inhibitory effect also behaved in a dose-dependent manner,and the EC 50was about 3.34μg/ml.To examine whether the decrease of viable tumor cells was caused by induced apoptosis,95-D cells were treated with GA-T and then were analyzed for annexin V-FITC binding.The experimental results are shown in Fig.4.The proportion of cells reactive with the annexin V-FITC conjugate indicated that target cells started to enter apoptosis after treatment.The number of apoptotic cells was about 50%at the concentration of 50μg/ml at 8h.This means that GA-T induced the apoptosis of tumor cells.At the same time,the cell cycle arrest at G 1phase was observed under the treatment of GA-T (Fig.5).Compared withcontrol,the percentage of cells in G 1phase increased from 48%to 76%(at 24h)with an addition of 50μg/ml of GA-T,whereas the percentage of cells in S phase decreased to 13%from 37%at the same condition.GA-T influences the integrity of mitochondria by decreasing the mitochondrial transmembrane potential (Δψm )The disruption of mitochondrial integrity is one of the early events leading to apoptosis.To assess whether the GA-T affects the function of mitochondria,potential changes in mitochon-drial membrane were analyzed by employing amitochondriaFig.2.Growth inhibition effects of GA-T on various cell lines.Viable cell number was detected using MTT reduction.Values are means±S.D.from triplicate cultures,and the experiments were repeated for five times with similarresults.Fig.3.Growth inhibition effects of GA-T against a highly metastatic lung cancer cell line (95-D).(A),cytotoxicity.After GA-T treatment at 0,10,25and 50μg/ml,viable cell number was detected by MTT reduction.(B),colony formation.After GA-T treatment at 0,2,5,10mg/ml,cells were fixed and stained with crystal violet and counted.Values are means±S.D.from triplicate cultures,and the experiments were repeated for five times with similarresults.Fig.4.GA-T induced apoptosis in 95-D cells.The cells were treated at the indicated time at 50μg/ml of GA-T and apoptosis was assayed by annexin V-FITC binding with flow cytofluorometry.Top right quadrant ,dead cells in late stage of apoptosis;Bottom right quadrant ,cells undergoing apoptosis;Bottom left quadrant ,viable cells.(A),0h;(B),4h;(C),8h.Shown are typical data from one of three independent experiments with similar results.For the apoptosis percentage,it takes the total percentage of viable cells,cells undergoing apoptosis,apoptotic cells and necrosis cells as100%.Fig.5.Cell cycle progression was blocked under GA-T treatment in 95-D cells at the indicated time at 50μg/ml.Symbols:blank bar,G 0–G 1phase;dark bar,S phase;gray bar,G 2/M phase.After GA-T treatment,cells were stained with PI and analyzed with flow cytometry.The results are the average of triplicates.For the percentage of cell cycle distribution,it takes the total percentage of cells at G 1–G 0phase,S phase,and G 2/M phase as 100%.208W.Tang et al./Life Sciences 80(2006)205–211fluorescent dye,DiOC 6.As shown in Fig.6,a drop in the mitochondrial membrane potential was observed.The data show that changes in the membrane potential were induced in treated 95-D cells during 4and 8h treatments.A significant decrease of Δψm was detected in cells treated with 50μg/ml GA-T for 4and pared to control,the decrease in the mean fluorescence density was about 10%and 16.7%,respectively.The results illuminate that GA-T could induce Δψm dissipation in a time-dependent manner.A drop in the mitochondrial membrane potential is usually accompanied by release of cyt -c into the cytosol.As shown in Fig.7,cyt-c levels in the cytosol of GA-T treated cells showed a rapid increase.A one-fold increase was seen within 4h.At 8h,about 3-fold increase in the cyt-c level was observed.The data indicate that GA-T increased the release of cyt -c to cytosol in treated tumor cells.GA-T induces activation of caspase-3but not caspase-8In general,induced apoptosis is often associated with activity of a series of caspases,such as caspase-3and caspase-8.In this work,the activity of caspase-3was detected in 95-D cells treated by GA-T.The data are shown in Fig.8A.GA-T noticeably stimulated the activity of caspase-3in tumor cells in a dose-dependent manner.The activity of caspase-3increases 2-and 3-fold respectively at 4and 8h under the drug concentration of50μg/ml compared with the control.In contrast,the activation of caspase-8was not detected during the 4h and 8h incubations (Fig.8B).To identify which caspases are functionally important for GA-T induced apoptosis,selective caspase inhibitors were used in our investigation.As shown in Fig.8C,the caspase-3inhibitor or pan-caspase inhibitor alone but not caspase-8inhibitor can reduce the apoptosis mediated by GA-T.GA-T modulates the p53and Bax expression,but does not affect bcl-2protein expressionThe expression of proteins including p53,Bcl-2and Bax may be involved in an intrinsic apoptosis pathway.In our case,under GA-T treatment,the expression of p53and Bax was found up-regulated in a time-dependent manner,whereas the expression of Bcl-2was not changed (Fig.9).GA-T inhibits the growth of solid tumor implanted in athymic miceWhen solid tumors in athymic mice were treated with the GA-T,the suppression of tumor growth was observed.Fig.10Fig.6.GA-T influences the mitochondrial membrane potential.The cells were treated at the indicated time at 50μg/ml of GA-T.Cells were analyzed as described in “Materials and methods ”.The results are the average of triplicates.Samples without drug treatment were taken ascontrol.Fig.7.Release of cytochrome c from mitochondria after GA-T treatment at the indicated time at 50μg/ml.Cells were analyzed as described in “Materials and methods ”.The results are the average oftriplicates.Fig.8.Effect of GA-T on activities of caspases.The cells were treated at the indicated time at 50μg/ml of GA-T.(A),caspase-3,which activity was detected by luminometer.(B),caspase-8,which activity was monitored using a microplate reader at 405nm.(C),percentage of apoptosis was quantified by annexin-V staining in the presence or absence (CK,control)of selected caspase-8and -3inhibitors.Results are the average of triplicates from one of the three independent experiments.209W.Tang et al./Life Sciences 80(2006)205–211shows the inhibition ratio of tumor growth for the GA-T treatment in nude mice.The results demonstrated that GA-T could suppress tumor growth in vivo.DiscussionIn this work,the treatment of a tumor cell line (95-D cells)with GA-T resulted in the inhibition of the cell growth in a dose-dependent manner.Our further experiments revealed that apoptosis induction and cell cycle progression block were simultaneously responsible for the inhibition of the tumor cell growth.The percentage of cells in G 1cell cycle phase was increased in 95-D cells under the GA-T treatment.For the effect of ganoderma extracts,the cell cycle blocked at the transition from G 1to S phase (Zhu et al.,2000)and G 2/M phase (Lin et al.,2003)were observed .The different effect may be caused by the variety of triterpenes in extracts,because the activities of triterpenes are dependent on their structures (Gan et al.,1998).Caspase cascade plays a key role in apoptosis procedure (Oubrahim et al.,2001).Caspase-3typically functions at the downstream of other caspases and directly activates enzymes that are responsible for DNA fragmentation in intrinsic apoptosis pathway.Caspase-8is considered as a signaling and key caspase in extrinsic pathway.Our data suggest that activation of caspase-3but not caspase-8was involved in the tumor cells'apoptosis induced by GA-T.The use of caspase inhibitors proved that caspase-3was associated with the induced apoptosis.Consistent with this conclusion is the finding that caspase-8inhibitor had no additive effect in preventing GA-T-mediated apoptosis.At the same time,stress-mediated apoptosis is often triggered by mitochondrial function loss and subsequent cyt-c release from mitochondria to cytosol.The role of mitochondria in GA-T-mediated apoptosis was also explored in this work.GA-T induced a loss of mitochondrial potential and the release of cyt-c to cytosol.Taken together,these results indicate that the apoptosis induced by GA-T was through intrinsic pathway related to mitochondrial dysfunction.In induced apoptosis,interactions between Bax and Bcl-2proteins on mitochondria have been postulated to associate with apoptotic pathways (Zong et al.,2003).Many chemotherapeutic drugs activate apoptosis as a function of their anticancer activity.Bcl-2and Bax have also been implicated as major players in the control of apoptosis pathway.Bcl-2and Bcl-xLpromote cell survival,whereas Bax promotes cell death (Yashita et al.,1994).It was suggested that the ratio of Bcl-2to Bax determines survival or death following apoptotic stimulus.Triterpene extract was found to modulate the expression of Bcl-2and Bax in some tumor cell lines (Choudhuri et al.,2002).In this work,the increase of Bax expression was observed whereas the expression of Bcl-2was not changed.This result was consistent with the reported data (Sang et al.,2001).The work suggests that the apoptosis under the GA-T treatment was by regulating the ratio of Bax/Bcl-2groups.The conclusion was similar to the effect of other triterpenes such as asiatic acid (Park et al.,2005)on tumor cells but it has not been known what effects ganoderma triterpenes have on tumor cell lines until now.In many cases,the p53protein has been identified as the effector of apoptosis signals (Levin,1997).It is a regulator of cell cycle progression and mediator of apoptosis in various cases.The key role of p53in the G 1/S checkpoint was its response to DNA damage.Now,there is some evidence that ganoderic acids can inhibit the topoisomerases and damage cellular DNA in our research (data not shown)and other work (Li et al.,2005).In this study,the expression of p53was up-regulated.This means that the biochemical events induced by GA-T were possibly associated with p53protein.Activation of p53may be stimulated by DNA damage under GA-T treatment,and activated p53might either trigger the onset of cell cycle arrest or induce the apoptosis in 95-D cells.On the other hand,we admit that this drug may not work in tumors with p53mutation.At this stage,the acting mechanism of GA-T against other tumor cell lines is not clear,and whether GA-T has another anti-cancer acting target or not is also unknown to us,and will require furtherstudies.Fig.10.The inhibition ratio of solid tumors in athymic mice byGA-T.Fig.11.Proposed pathway involved in apoptosis induced byGA-T.Fig.9.Time-dependent expression of apoptosis regulating proteins under GA-T treatment as observed.(A),p53;(B),Bcl-2;(C),Bax.Following 4h and 8h exposure to 50μg/ml GA-T,the total cellular protein was extracted,resolved using SDS-PAGE,and western blotting analysis was done with indicated antibodies.Data represent means from two independent experiments.210W.Tang et al./Life Sciences 80(2006)205–211Taken together,based on the results obtained above and the current paradigms of apoptosis reported in the literature,a molecular pathway of apoptosis induced by GA-T was proposed as in Fig.11.As it is not yet completely verified,further work can be done to investigate related interesting issues such as the confirmation of apoptosis blockage by blocking p53or Bax induction.This work also suggests that GA-T may be a natural potential apoptosis-inducing agent for highly metastatic lung tumor and it may be also applied to treat other tumor cell lines. 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小鼠卵巢组织的玻璃化冷冻研究
华中科技大学硕士学位论文小鼠卵巢组织的玻璃化冷冻研究姓名：***申请学位级别：硕士专业：妇产科学指导教师：***20060401华中科技大学同济医学院硕：Ｉｊ毕业论文．附图图１Ａ小鼠新鲜卵巢组织切片（×４００）图１Ｂ实验组Ｉ复苏后的组织切片（×４００）图１ｃ实验组ＩＩ复苏后的组织切片（×４００）图１Ｄ实验组Ⅲ复苏后的组织切片（×４００）图２玻璃化冷冻复苏后小鼠卵巢组织的电泳结果图５玻璃化冷冻复苏后的卵巢组织中始基卵泡透射电镜照片ｘ１００００２０华中科技大学同济医学院硕士毕业论文图４卵巢组织暴露于不同玻璃化冷冻溶液卵母细胞的存活率比较图６Ａ分离玻璃化冷冻复苏的卵巢组织所得图６Ｂ玻璃化冻融卵巢组织分离出的窦前卵泡４００ｘ０ＧＣ２００ｘ华中科投大学同济医学院顾：Ｉ‘毕业论文图３ＰＩ染色示死细胞幽８Ａ幽８Ｃ图８Ｅ幽７ＭＩＩ期卵母细胞纺锤体荧光染色镜检结果幽８Ｂ图８Ｄ图８Ｆ小鼠卵巢组织的玻璃化冷冻研究作者：陈薪学位授予单位：华中科技大学1.Meirow D.Nugent D The effects of radiotherapy and chemothrapy on female reproduction 20012.Blatt J Pregnancy outcome in long-term survivors of childhood canceer 19993.Abir R.Fisch B.Nitke S.Okon,E, Raz,A. 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freezing on the organization of the meiotic spindle of the mouse oocytes 199252.Oktay K Ovarian cryopreservation and transplantation:Preliminary findings and imp,icatins for cancer patients 200153.Oktay K.Buyuk E.Davis O.Yermakova I Veeck I Rosenwals Z Fertility preservation in breast cancer pantients:in vitro fertilization and embryo cryoptesevation after ovarian stimulation with tamxifen 200354.Kutluk Oktay.Bulent Alp Aydin.Guvenc Karlikaya A technique for laparoscopic transplantation of frozen-banked ovarian tissue 2001(06)55.Okatay K.Guvenc G.Karlikay A Ovarian cryopreservation and transplantation:basic aspects 200056.Kutluk Oktay.Erkan Buyuk.Lucinda Veeck.Nilica Zaninovis Kangpy Xu Takumi Takeuchi Michael Opsahl Zev Rosenwaks Embryo development after heterotopic transplantation of cryopreserved ovarian tissue 200457.J Donnez.MM Dolmans.D Demylle.P Jadoul, C Pirard, J Squifflet, B Martinez-Madrid, A van Langendonckt Livebirth after orthotopic transplantation of cryopreserved ovarian tissue 2004(9443) 58.Dror Meirow.Jacob Levron.Talia Eldar-Geva Pregnancy after Transplantation of Cryopreserved Ovarian Tissue in a Patient with Ovarian Failure after Chemotherapy 200559.Jelinkova L.Selman HA.Arav A Twin pregnancy after vitrification of 2-pronuclei human embryos 200260.Mukaida T.Nakamura S.Tomiyama T.Wada S, Oka C, Kasai M and Takahashi K Vitrification of human blastocysts using cryoloops:clinical outcome of 223 cycles 200361.Yoon TK.Kim TJ.Park SE.Hong SW, Ko JJ, Chung HM Cha KY Live births after vitrification of oocytes in a stimulated in vitro fertilization-embryo transfer program 200362.Mohamed A Bedalwy.Elisabeth Jeremias.Raffi Gurunluoglu.Mahmoud R.Hussein, Maria Siemianow,Charles Biscotti and Tommaso Falcone Restoration of ovarian function after autotransplantation of intact frozen-thawed sheep ovaries with microvascular anastomosis 2003(03)63.Tommaso Falcone.Marjan Attaran.Mohamed A Bedaiwy.Jeffery M.Goldberg Ovarian function preservation in the cancer patient 2004(02)64.Meirow D.Nugent D The effects of radiotherapy and chemotherapy on female reproduction 2001(06)65.Akiko Hasegawa.Yukari Hamada.Tzvetozar Mehandjiev.Koji Koyarna In vitro growth and maturation as well as fertilization of mouse preantral oocytes from vitrified ovaries 2004(zk)66.Isachenko E.Isachenko V.Rahimi G.Nawroth E Cryopreservation of human ovarian tissue by direct plunging into liquid nitrogen 2003(02)67.Isachenko V.Isachenko E.Rahimi G.Krivokharchenko A, Alabart JL, Nawroth E Cryopreservation of human ovarian tissue by direct plunging into liquid nitrogen:negative effect of disaccharides in vitrification solution 2002(05)68.Nisolle M.Casanas-Roux F.Qu J Distribution and epidermal growth factor expression of primordial follicles in human ovarian tissues before and agter cryopreservation 200069.Christiani Andrade Amorim.Davide Rondina.Ana Paula.Ribeiro Rodrigues,Paulo Bayard Dias Goncalves. .JoséRicardo de Figueiredo and Alessandro Giorgetti Cryopreservation of isolated ovine primordial follicles with propylene glycol and glycerol 2004(zk)70.Banu Demirci.Jacqueline Lornage.Bruno Salle.Lucien Frappart Michel Franck and Jean Francois Guerin Follicular viability and morphology of sheep ovaries after exposure tocryoprotectant and cryopreservation with different freezing protocols 2001(04)71.Ali J Factors affecting the ultrarapid vitrification and crypreservation of embryo s 199272.Mojdeh Salehnia.Esmat Abbasian Moghadam.Mojtaba Rezazadeh Velojerdi Ultrastructure of follicles after vitrification of mouse ovarian tissue 2002(03)73.Mohamed A Bedaiwy.Elisabeth Jeremias.Raffi Gurunluoglu.Mahmoud R.Hussein, Maria Siemianow,Charles Biscotti and Tommaso Falcone Restoration of ovarian function after autotransplantation of intact frozen-thawed sheep ovaries with microvascular anastomosis 2003(03)74.Banu Demirci.Bruno Salle.Lucien Frappart.Michel Franck Jean Francois Guerin and Jacqueline Lornage Morphological alterations and DNA fragmentation in oocytes from primordial and primary follicles after freezing-thawing of ovarian cortex in sheep 2002(03)75.Siebzehnrubl E.Kohl J.Dittrich R Freezing of human ovarian tissue:not the oocytes but the granulose is the problem 200076.Hongbo Wang.Stephen Mooney.Yan Wen Follcle development in grafted mouse wvaries after cryopreservation and subcutaneous transplantation 200277.Radich J The use of PCR technolohy for detecting minimal residual disease in patients with leukemia 199978.Kim SS.Battaglia DE.Soules MR The future of human ovarian cryopreservation andtansplantation:Fertility and beyond 2001(06)79.Debra A Gook.B A Mccully.D H Edgar.J.C.Mc Bain Development of antral follicles in human cryopreserved ovarian tissue following xenografting 2001(03)1.唐永红.TANG Yong-hong激光扫描共聚焦显微镜在激光照射诱导细胞凋亡研究中的应用[期刊论文]-激光生物学报2006,15(5)2.代西梅.黄群策.李国平.胡秀明.秦广雍.DAI Xi-mei.HUANG Qun-ce.LI Guo-ping.HU Xiu-ming.QIN Guang-yong 激光扫描共聚焦显微镜观察水稻双受精过程[期刊论文]-河南农业科学2007(6)3.马云涛应用激光共聚焦显微镜技术对脑脊液脑膜癌细胞内质网、线粒体的相关研究[学位论文]2010引用本文格式：陈薪小鼠卵巢组织的玻璃化冷冻研究[学位论文]硕士 2006——附加文档一篇，不需要的朋友下载后可以编辑删除，谢谢——工程概况刘家湾北段市政工程总长度545m；道路设计红线宽度主线30m,一副路面；车行道16m;绿化带2*4m；人行道2 *3m。
生物学课后试题1-8标准答案
生物学课后试题1-8标准答案1. What is the process of photosynthesis?Photosynthesis is the process by which green plants and some other organisms use sunlight to synthesize nutrients from carbon dioxide and water. During photosynthesis, plants convert light energy into chemical energy, which is stored in the form of glucose. This process takes place in the chloroplasts of plant cells and involves the absorption of light energy by chlorophyll, the conversion of carbon dioxide and water into glucose and oxygen, and the release of oxygen as a byproduct.2. What is the role of DNA in inheritance?DNA, or deoxyribonucleic acid, is a molecule that carries the genetic instructions used in the growth, development, functioning, and reproduction of all known living organisms. It plays a crucial role in inheritance by transmitting genetic information from one generation to the next. DNA contains the genes, which are specific sequences of nucleotides that code for the production of proteins. These proteinsdetermine the traits and characteristics of an organism and are passed on from parents to offspring during reproduction.3. Describe the process of mitosis.Mitosis is the process of cell division that results in the formation of two identical daughter cells. It consists of four main stages: prophase, metaphase, anaphase, and telophase.1. Prophase: The chromatin condenses into visible chromosomes, the nuclear membrane dissolves, and the mitotic spindle starts to form.2. Metaphase: The chromosomes align along the equatorial plane of the cell and attach to the spindle fibers.3. Anaphase: The sister chromatids separate and are pulled towards opposite poles of the cell by the spindle fibers.4. Telophase: The chromosomes decondense, the nuclear membranes reform around each set of chromosomes, and the cytoplasm divides through cytokinesis, forming two daughter cells.4. What are the functions of the respiratory system?The respiratory system is responsible for facilitating the exchange of oxygen and carbon dioxide between the body and the environment. Its main functions include:1. Breathing or ventilation: The process of inhaling oxygen-rich air and exhaling carbon dioxide-rich air.2. Gas exchange: The transfer of oxygen from the lungs to the bloodstream and the removal of carbon dioxide from the bloodstream to the lungs.3. Regulating blood pH: By controlling the levels of carbon dioxide in the body, the respiratory system helps maintain the pH balance of the blood.4. Sense of smell: The nose and the olfactory system allow us to detect and distinguish different odors in the environment.5. What is the role of enzymes in biochemical reactions?6. What is biodiversity and why is it important?Biodiversity refers to the variety of life forms and ecosystems on Earth. It includes the diversity of species, genes, and ecosystems. Biodiversity is important for several reasons:1. Conservation of ecosystems: Ecosystems with high biodiversity tend to be more stable and resilient to changes in the environment. They provide essential services such as water and air purification, climate regulation, and nutrient cycling.2. Economic value: Biodiversity supports industries such as agriculture, forestry, fisheries, and tourism, which contribute to economic growth and livelihoods.3. Medicinal resources: Many medicines are derived from plants and animals, and the loss of biodiversity could result in the loss of potential future sources of medicine.4. Cultural and aesthetic value: Biodiversity enriches our lives by providing beauty, inspiration, and cultural heritage.7. Explain the process of evolution by natural selection.Evolution by natural selection is the process by which species gradually change over time in response to changing environmental conditions. It is guided by the following principles:1. Variation: Individuals within a population show variation in their traits.2. Heredity: Traits are passed on from parents to offspring through genetic inheritance.3. Differential reproduction: Organisms with advantageous traits are more likely to survive and reproduce, passing on their advantageous traits to future generations.4. Natural selection: From generation to generation, the frequency of traits that improve an organism's chances of survival and reproduction increases, while the frequency of detrimental traits decreases.5. Adaptation: Over time, populations accumulate beneficial traits that enable them to better survive and reproduce in their specific environment.8. What are the main functions of the circulatory system?The circulatory system, also known as the cardiovascular system, is responsible for the transportation of oxygen, nutrients, hormones, and waste products throughout the body. Its main functions include:1. Oxygen transport: The circulatory system carries oxygen from the lungs to the body's tissues and organs.2. Nutrient transport: It transports nutrients absorbed from the digestive system to the body's cells for energy and other vital functions.3. Waste removal: The circulatory system carries metabolic waste products, such as carbon dioxide and urea, to the lungs and kidneys for elimination from the body.4. Hormone distribution: Hormones produced by various glands are transported through the blood to their target organs and tissues.5. Temperature regulation: The circulatory system helps regulate body temperature by redistributing heat throughout the body.。
小学上册T卷英语第二单元期末试卷
小学上册英语第二单元期末试卷英语试题一、综合题(本题有100小题，每小题1分，共100分.每小题不选、错误，均不给分)1.The _____ (山脉) is beautiful in winter.2.What do we call the sound made by thunder?A. BoomB. CrashC. RoarD. Bang3.What do you call a female horse?A. MareB. StallionC. ColtD. Foal4.I have a pet ________ named Max.5.The _____ (桌子) is made of wood.6.Einstein's theory of relativity changed our understanding of ______.7.What is the capital of Indonesia?A. BaliB. JakartaC. BandungD. SurabayaB8.The owl is active at ________________ (夜晚).9.How many teeth does an adult human usually have?A. 28B. 30C. 32D. 2610.My sister enjoys __________ (手工).11.Which shape has four equal sides?A. TriangleB. CircleC. SquareD. RectangleC12.The ________ (气候变化) affects wildlife.13.Plants provide _______ for many animals.14.In _____ (摩洛哥), you can visit the Atlas Mountains.15.The Earth's crust is primarily composed of ______ rocks.16.The _____ (elephant/giraffe) is tall.17.What is the term for a baby chicken?A. PuppyB. KittenC. ChickD. Calf18.ts can ______ (对抗) diseases effectively. Some pla19.I like to _____ (闪烁) lights.20.I enjoy exploring ______ in my town.21. A ______ has a unique pattern on its fur.22.What is the color of a typical grape?A. GreenB. PurpleC. RedD. All of the above23.I enjoy playing ______ after school.24.What do we call the time of year when it is very hot?A. SpringB. SummerC. AutumnD. Winter25.What do you call the time it takes for the Earth to go around the Sun?A. DayB. MonthC. YearD. CenturyC26.My mom loves __________ (探索新的思想).27.My uncle has a ____ (farm) with many animals.28.The fish swims in the ___ (water).29.The ______ is an organ that helps us see.30.Elements are divided into metals, nonmetals, and ________.31.The chameleon can change its ______ to hide.32.The salad is very ___ (fresh).33.__________ (惰性气体) are used in lighting and welding due to their non-reactive nature.34.I can ______ (保持) a clear mind under pressure.35.An acid tastes ______.36.The cake is _______ (decorated) with strawberries.37.How do we measure temperature?A. MeterB. ScaleC. ThermometerD. Ruler38.My cousin loves to bake ____.39.I have a toy ______ (机器人) that can talk and dance. It is very ______ (有趣).40.We have a ______ (快乐的) family tradition for special occasions.41.What is the name of the famous Italian dish made with pasta?A. PizzaB. RisottoC. LasagnaD. Fettuccine42. A ____ has a long, slender body and is very agile.43.My dad loves __________ (模型制作).44.My dog has a very ______ (友好的) personality.45.The nurse, ______ (护士), works in the emergency room.46.What do you call a young porcupine?A. PorcupetteB. KitC. PupD. Calf47.How many fingers do we have on two hands?A. TenB. EightC. TwelveD. Six48.The capital of Lesotho is ________ (马塞卢).49.The ant colony is very _________. (组织)50.You can find ______ (药草) in the kitchen.51.What is 2 + 2?A. 3B. 4C. 5D. 652.The process of neutralization produces _____ and water.53.The ______ helps retain water in plants.54.The book is ________ interesting.55.The puppy is _______ (在追逐)蝴蝶。
Nuclear Organization and Transport-Wuhan(中文)
核孔选择性地允许大分子从细胞核到细胞质或从细胞质到细胞核的运输
dynamics of nucleus during cell division (mitosis)
有丝分裂时核呈现动态变化
lamins and the nuclear envelope disassemble and reassemble during mitosis
染色质是由核小体及 更高级的结构包装而 成
nucleosomes are complexes of histones wrapped with DNA 核小体是包裹DNA的组蛋白ures that move to permit access to DNA sequences 核小体是动态结构，能移动释放DNA序列
nucleo-cytoplasmic transport through nuclear pores
核孔的核质交换
nuclear pores control transport between the cytoplasm and nucleus （核孔可调控核质交换）
transport requires either import or export signals on transported molecules 大分子转运需要出核和入核信号
active genes
inactive genes
Van Bortle amd Corces 2012
organization of active and inactive chromatin 活 化与非活化的染色质结构
Politz et al. 2013
the organization of chromatin changes as genes are made active or inactive during cellular differentiation（在细胞分化的过程中，染色质的 结构随基因的活化与失活而变化）
Thermodynamic properties of nuclear pasta in neutron star crusts
1
1
Introduction
பைடு நூலகம்
In the outer part of a neutron star, nuclei are considered to mainly determine the state of matter in equilibrium [1]. Except for a thin envelope of the star, due to Coulomb interactions, nuclei form a bcc lattice neutralized by a roughly uniform sea of electrons. With increasing density, weak interactions render nuclei neutron-rich via electron captures. Then, at a density of about ∼ 4 × 1011 g cm−3 , neutrons begin to drip out of these nuclei. The crystalline region of the star (not) including a gas of the dripped neutrons is usually referred to as an inner (outer) crust. In the deepest region of the inner crust, corresponding to densities just below the normal saturation density ρs ∼ 3 × 1014 g cm−3 , not only are nuclei expected to have rod-like and slab-like shapes, but also the system is expected to turn inside out in such a way that the constituents of the original nuclei form a liquid containing rod-like and roughly spherical bubbles of the dripped neutrons. These transformations, as originally indicated by Ravenhall et al. [2] and Hashimoto et al. [3], stem from a delicate competition between the nuclear surface and Coulomb energies at small internuclear spacings. Recent calculations of the ground state of matter in the crust, performed by using specific nuclear models [4, 5, 6], indicate that at a density of order 1013 g cm−3 , rather small compared with ρs , roughly spherical nuclei turn into elongated rod-like nuclei. Accordingly, the lattice structure is changed from a regular bcc lattice to a two-dimensional triangular lattice. With further increasing density, these rod-like nuclei are transformed into slab-like nuclei, which are arranged in the form of a layered lattice. After that, a twodimensional triangular lattice of rod-like bubbles and a bcc Coulomb lattice of roughly 2
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a rXiv:n ucl-e x /5828v124A ug25The π→ππprocess in nuclei and the restoration of chiral symmetry CHAOS Collaboration N.Grion a,1,M.Bregant a,b ,P.Camerini a,b ,E.Fragiacomo a,b ,S.Piano a,b ,R.Rui a,b ,E.F.Gibson c ,G.Hofman g E.L.Mathie d ,R.Meier e ,M.E.Sevior f ,G.R.Smith g,2and R.Tacik d .a Istituto Nazionale di Fisica Nucleare,34127Trieste,Italy b Dipartimento di Fisica dell’Universita’di Trieste,34127Trieste,Italy c California State University,Sacramento CA 95819,USA d University of Regina,Regina,Saskatchewan,Canada S4S 0A2e Physikalisches Institut,Universit¨a t T¨u bingen,72076T¨u bingen,Germany f School of Physics,University of Melbourne,Parkville,Vic.,3052,Australia g TRIUMF,Vancouver,B.C.,Canada V6T 2A3Abstract:The results of an extensive campaign of measurements of the π→ππprocess in the nucleon and nuclei at intermediate energies are presented.The measurements were motivated by the study of strong ππcorrelations in nuclei.The analysis relies on the composite ratio C A ππ,which accounts for the clear effect of the nuclear medium on the ππsystem.The comparison of the C A ππdistributions for the (ππ)I =J =0and (ππ)I =0,J =2systems to the model predictions indicates that the C A ππbehavior in proximity of the 2m πthreshold is explainable through the partial restoration of chiral symmetry in nuclei.PACS:25.80HpI.INTRODUCTIONSpectral properties of pion pairs interacting in the I=J=0channel (the σ-channel)are predicted to vary significantly from the vacuum to nuclear matter as a consequence of the partial restoration of chiral symmetry.As an example,the vacuum spectral function of σ,a broad (Γ∼500MeV)resonance centered at ∼500MeV,substantially reshapes in nuclear matter by forming a peak-like structure at around 2m π[1,2,3].The underlying theory regards the σmeson as a ¯q q excitation of the QCD vacuum,in which the spontaneous breaking of the chiral symmetry leads to the σ-πmass difference.The sigma (J P =0+)isalso the chiral partner of the pion(J P=0−).When the properties of theσmeson are studied in nuclear matter,the theory predicts a substantial change of theσspectral function,which strongly reduces theσ-πmass difference.This occurrence indicates that nuclear matter partially restores the chiral symmetry.The I=0ππinteraction in nuclear matter is also studied in Ref.[4],which reflects the current theoretical understanding on this topic.An additional source of reshaping of theσspectral function at around threshold is yielded by standard many-body correlations;i.e.,the P−wave coupling of pions to particle−hole and∆−hole states[2,3,5].The combined effect of partial restoration and collective P-wave pionic modes produces a conspicuous enhancement of theσspectral function at around the 2mπthreshold[2,3].This letter presents further analysis of experimental results on the π→ππprocess near the2mπthreshold,which are then related to the direct observation ofππin-medium correlations.In this regard,final pion pairs are studied in the vacuum and in the nuclear medium,and are further examined in the isospin0and2channels. The comparison of different isospin channels conveys additional information on the spectral changes of theσ-channel(I=0)with respect to the non-resonant I=2channel.Finally,the data from the present measurements will directly probe theσ-spectral predictions around threshold and accordingly the underlying physics of chiral symmetry restoration.Theσ(or f0(600))meson is understood to be a broad resonant stateΓσ∼mσ∼500 MeV which predominantly decays into two S-wave pionsσ→ππ[6].Theσbroad structure makes this meson difficult to directly observe via theπN→ππN elementary reaction[7], or heavy meson decays[8].A systematic analysis of a broad sample of data involving pion pairs in the I=J=0channel however providesfirm evidence ofσ[9].A clear signature ofσin the vacuum appears controversial.Conversely,the nuclear medium may condensate I=0 pion pairs by changing the structure of the QCD vacuum;therefore,the study ofσby means of two coincident I=0pions via theπ→ππprocess appears appropriate.Theσspectral properties are studied by means of theππinvariant mass and the com-posite observable C Aππ,which is described in Sec.3.In order to normalize this observable to pion production on the nucleon and explicitly consider the ratio for nuclei from2H to208Pb, a new analysis of our previously published[10]pion production data on the nucleon was completed as a function of the same kinematic quantities as were used for the nuclear data.C A ππappears slightly different from the previously published one,which was normalized todeuterium[11].In addition,new results for the composite observable are presented for Sc as a function of incident energy.Thefinal pions have an energy distribution which is broadly centered between20-50MeV,depending on the energy of the projectile[11,12].In this en-ergy range,an earlierπ2πmeasurement reported that the shape of spectra was only slightly altered byfinal state interactions[13].This resultfinds a qualitative explanation in the long mean-free path of low-energy pions in nuclear matter.The mean-free path of pions exceeds 10fm forρ=ρ0/2at Tπ=50MeV[14],which highly reduces the pion distortions due toπN final-state interactions.Furthermore,pion absorption has only the effect of removingfinalpions and the removal is mildly dependent on the pion energy in the interval50±30MeV [15]thus causing little reshaping of pion spectra.Finally,pion distortions due to otherπA reactions can safely be neglected[15].Previous studies of theπA→ππA′reaction showed that at intermediate energies the pion production process takes place at the nucleus skin ρ∼1ρ0for208P b by employingγ’s of energies in the range400-460MeV.3II.THE MEASUREMENTThe data were taken at the M11pion channel of TRIUMF with the CHAOS spectrometer [17].Both positive and negative pions were used to study the pion-production reaction(π2π) as a function of the atomic mass number(A)and the projectile incident energy(T):π±p→π+π±n at T=243,264,284and305MeV(1)π+A→π+π±X with A:2H,12C,40Ca and208P b at T=283MeV(2)π+Sc→π+π±X at T=243,264,284and305MeV(3) The measurements from(1)to(3)were performed under the same kinematic conditions to ensure a direct comparison among theπ2πdata.In addition,final pion pairs were detected in coincidence to avoid the overwhelming background from the reaction of pion scattering. The results of the measurements(1),(2)and(3)were previously published in Refs.[10],[11] and[12],respectively.The CHAOS spectrometer consists of a dipole magnet,four rings of cylindrical wire chambers and a multilayer mass-identification system(CFT).The events were analyzed in the plane of the reaction due to the geometry of the dipole;that is,for azimuth anglesΘranging from0◦to360◦and for zenith anglesΦfrom-7◦to+7◦.Final pions(from(1) to(3))were detected with an energy resolution ofδT/T=4-7%(σ),for the CHAOSfield set at0.5-0.6T.Such afield also established the pion detection threshold,which was11 MeV.The CFT system was designed to delivered thefirst level trigger and mass identify charged particles;i.e.,e’s,π’s,p’s and d’s.The particle mass identification(PID)relies on the observed correlation between the trace momentum and the pulse heights in the CFT layers.Reconstructed events with a valid PID were further restricted to theπ2πphase-space volume before beingfinally saved.The prime PID capability of CHAOS is illustrated in Fig. 1,which shows the missing mass distribution of reactions(1)at T=264MeV.The missing mass expected is the neutron mass irrespective of the projectile charge and energy.In fact,Figure1:Missing mass distribution of theπ−p→π+π−n reaction at an incident projectile energy of264 MeV.The expected missing mass is the neutron mass,the distribution is peaked at938.3MeV.a distinct peak centered around940MeV with aσof about3MeV is observed in each channel.By averaging the peak-value over the four energies and the two reaction channels, the missing mass distribution yields a mean value of941.2±3.0MeV which is consistent with the neutron mass.III.THE OBSERVABLETheπ2πexperimental results will be compared to the theoretical predictions via the composite observableC A ππ=σ(M Aππ)/σA TFigure2:Simulated behavior of C Scππfor CHAOS(filled histogram)and for an ideal4πdetector(open histogram)as a function of theππinvariant mass(Mππ).The reactions simulated areπ+45Sc→π+π−p 44Sc(upper panel)andπ+45Sc→π+π+n44Ca(lower panel)at an incident projectile energy of284MeV.which therefore is better suited for the discussion of the observed effects than the invariant mass distributions themselves.Such an observable is useful to focus on the medium modification of meson properties.C A ππin fact describes the clear effects of the nuclear medium on theππinteracting system.The pion-production reaction in nuclei is a quasi-free process,which requires a single nucleon πN→ππN[13];therefore,the ratio ofσ(M Aππ)toσ(M Nππ)is loosed from the reaction mech-anism,and accordingly is C Aππ.The normalization ofσ(M Aππ)toσA T removes the dependence of C Aππfrom the number of scattering centers in nuclei,since both terms depend equally on A.Furthermore,the limited acceptance of CHAOS should slightly affect C Aππsince the detector acceptance is the same for N and A.In order to verify such an assumption,the behavior of C Aππwas simulated for CHAOS(open histogram)and an ideal4πdetector(filled histogram),and the results of the simulations are shown in Fig.2for theπ+45Sc→π+π−p 44Sc(upper panel)andπ+45Sc→π+π+n44Ca(lower panel)reactions at284MeV.The histograms were plotted without requiring any normalization,but the observables forming the nominator(denominator)of C Aππwere generated by feeding the Monte Carlo code with the same number of input events.The out-of-plane behavior of theπN(A)→ππN(A′)re-actions was accounted for by the model described in Ref.[5](and references therein quoted). The histograms display a monotonic decrease and nearly the same intensities at the varying of Mππ,with the exception of a shallow dip at Mππ∼350MeV for the CHAOS distribution.This convincingly demonstrates that C Aππis both weakly related to the detector acceptance and nearly independent of the reaction channel.Some models which describe theππdynamics in nuclear matter do not deal with theπ2πreaction mechanism nor account for the nuclear structure[1,2,3].These models focus on understanding how nuclear matter alters the vacuum structure of QCD and the repercussions on the spectral properties of mesons and hadrons.Mesons are of prime interest because they are considered as the elementary¯q q excitation of the vacuum.In this framework,the observable C Aππcan be quantitatively compared to the model predictions.At the variance, the model quoted in Ref.[5],provides a comprehensive study of theπA→ππX reaction: it accounts for the elementary process of pion productionπN→ππN as well as standard nuclear effects(Pauli blocking,Fermi motion,etc.).It also examines the effects of the nuclear environment on J=I=0interacting pion pairs via the P−wave coupling of pions to particle−hole and∆−hole configurations[18].The model,which embeds the CHAOSacceptance,predictsσ(M A(N)ππ)andσA(N)Ttherefore C Aππfor theπ+→π+π±reaction channels.IV.THE A-AND T-DEPENDENCE OF C AππThe error bars of the C Aππdata points plotted infigures from3to5account solely for statistical uncertainties,which primarily reflect those of measurements(2)and(3).The systematic uncertainties associated to C Aππrange from15.0%(A-dependence,measurement (2))to16.7%(T-dependence,measurement(3)),which must be summed in quadrature with the statistical ones to obtain the overall uncertainties.The A-dependence of the composite ratio is reported in Fig.3for a projectile kinetic energy of284MeV.In theπ+π−channel, pion pairs largely(∼95%)couple to I=J=0quantum numbers[11,19];however,the fraction of I=J=0pion pairs which couple to theσ-meson cannot be established by the present measurement.The pure isospin I=2is instead always reached byπ+π+pairs.In this isospin channel,C Aππbarely depends on A:data overlap from2H to208P b and the weak threshold enhancement is primarily due to phase space as denoted by the C Scππbehavior in Fig.2(see also discussion of Fig.5).Theσ-channel is characterized by a substantial dependence on A but only for A>2,when nuclear matter is realized.The C Aππobservable is compared with the model predictions of Ref.[5]for A=40Ca(continuous line).The agreement is good for theπ+π+channel,except for the low-energy part of the spectrum where the model calculations underestimate the data by nearly a factor of two.The model fails also to reproduce the threshold enhancement of C Aππfor theπ+π−channel,which indicates that the model fails to account for medium modification on pion pairs interacting in theσ-channel. In the framework of this model,an explanation of the threshold enhancement of C Aππmay be related to the modifications of theπ→ππelementary amplitude inside nuclear matter. In fact,a modification of some pieces of this amplitude may modify the strong interferences present at threshold,thus causing a significant reshaping of C Aππ.Studies are in progressFigure3:A-dependence of C Aππas a function of theππinvariant mass at an incident projectile energy of 284MeV.The continuous lines are the result of the model predictions of Ref.[5].[20].The T-dependence study of C Aππdone for A=45Sc delivers the same general picture as the A-dependence,Fig. 4.A strong enhancement is observed for C Aππin proximity of the 2mπthreshold for the isospin0channel(left panel),while C Aππisflat over theππinvariant mass range for I=2(right panel).For a selected isospin channel,C Aππdepicts a behavior weakly varying with T.This is consistent with a previous study on the properties of the pion production reaction,which were based on the model calculation of Ref.[5].The study shows that the average nuclear density(ρ)probed by incident pions barely changes from240to 320MeV.In fact,ρ∼0.36ρ0,which localizes the reaction to occur at the nucleus surface.In order to compare the C Aππdistributions with similar results from other available theories [1,2,3],theπ2πdata must be normalized to their phase space.This is because such theories deal only with pion pairs in nuclear matter taking no regard to the reaction of pion production;therefore,to its phase space.Fig5depicts the C Aππdistributions divided by the reaction phase space,which also accounts for the CHAOS acceptance.In theπ+π+ channel,C Aππ’s areflatly distributed at around1,and the distributions cannot factually be distinguished from A=2to A=208.This clearly shows that the nuclear medium leaves the isospin2ππinteraction substantially unaltered.Strong medium modifications of the elementaryππinteraction are observed in the isospin0channel but only for A>2;in fact, the C Aππintensities display a sharp increase at around2mπsolely for12C,40Ca and208P bFigure4:T-dependence of C Aππas a function of theππinvariant mass.(left panel).For2H,C Aππis a relativelyflat distribution in Mππ,without any indication of a threshold enhancement.For the examined nuclei,the composite ratio C Aππis compared to the model predictions [1,2,3],which are normalized to the data at Mππ>340MeV.The open diagram represents the results of Ref.[3]Fig.7(a),forρ=0.5ρ0.In this model,the threshold enhancement is due to collective P-wave pionic modes as well as S-wave pionic modes,which largely contributes to the intensity at around the2mπthreshold.The P-wave modes are described by the standard phenomenology of nuclear physics;that is,the P−wave coupling of pions to particle−hole and∆−hole configurations.The collective S-wave modes are studied via the LinearσModel developed to account forfinite nuclear densities;in this study,the parameter ρcan vary from0to2ρ0.The theory relates theππinteraction in the scalar-isoscalar channel to the appearance of theσ-meson and,finally,to the partial restoration of chiral symmetry in the nuclear medium.Thefilled diagram in Fig.5is an earlier theoretical result[1],which is based on the existence of theσ-meson in nuclear matter(ρ=ρ0),σbeing generated by thefluctuation of the<¯q q>chiral order parameter of QCD.The calculations depend on a complex parameterΦ(ρ),which forρ=ρ0can vary from0.7to0.9.In Fig.5,Φ(ρ=ρ0)=0.8. In the theory,theσ-meson reflects its existence by means of a marked enhancement of the spectral function at∼2mπ,which is a phenomenon commonly associated to the(partial)Figure5:A-dependence of C Aππnormalized to theπA→ππN[A−1]phase space(PS)at an incident projectile energy of284MeV.The phase-space simulations embody the CHAOS acceptance.The open and filled diagrams are the result of the model predictions of[3]and[1],respectively,which are normalized to the data above340MeV.restoration of the chiral symmetry.The above comparison between experimental results and theoretical predictions clearly indicates that theππinteraction is strongly modified by the presence of nuclei solely for I=J=0pion pairs.Furthermore,collective P-wave pion modes are far from explaining the strength at∼2mπ;i.e.,predictions of[5]reported in Fig. 3.On the other hand,the inclusion in the models of collective S-wave pionic modes is able to yield the requested threshold intensity even atρ<ρ0;i.e.,calculations of Refs.[1,2,3]reported in Fig.5.V.CONCLUSIONSThe data discussed in the present letter are the results of an extended campaign of measurements of theπN(A)→ππN(A′)reactions at several intermediate energies,which involved the CHAOS collaboration at TRIUMF.Only charged pions were detected,which allowed theππsystem to be studied in the isospin0and2channels.The simultaneous studyof the two isospin channels was essential to establish the correct size of theσ-strength.The only observable employed to reduce the data was the composite ratio C Aππ,which accounts for the clear effect of the nuclear medium onfinal pion pairs.Such an observable is nearly independent of the detector acceptance.In general,the nuclear medium has a negligible effect on the(ππ)I=2,J=0system:the strength of theππinteraction appears nearly the same in the vacuum as well as in the nuclear medium.In fact,the C Aππdistributions are planar at the varying of Mππregardless of A.In theπ+π−channel,the(ππ)I=J=0interaction is strongly modified by the medium even at moderate densities(i.e.,ρ∼13ρ0for208P b,which nearly doubles the density probed by the CHAOS measurements.Fig.2of Ref.[16] shows the TAPS Cππratio in comparison with the CHAOS ratio;in this case,the lead data are scaled to the carbon data.At the2mπthreshold,the TAPS ratio exceeds by∼1.2times the CHAOS ratio,which only partially reflects the higher density inspected by the TAPS measurements.On the other hand,Fig.5(left panel)yields C Aππ∼8at threshold for C or Ca,which tends to favor the picture of a rapidly raisingσformation as soon as an isospin0ππsystem establishes into the nuclear medium even of moderate density.It isfinally worthwhile commenting the results of a recent theoretical work on theγ→ππreaction in nuclei[21].The model examines the production and propagation of pion pairs in nuclear matter by using a semi-classical approximation and by fully accounting for the final state interactions of pions with the nuclear medium.The latter are found to distort considerably theππinvariant mass distributions,which are then used for comparison to the TAPS data(i.e.,Fig.4of Ref.[21]).The model predictions are capable of describing the threshold behavior of the I=0γ→π0π0reaction channel for both12C and208P b.The pre-dictions from the same model however fail to reproduce the invariant mass distributions of the I=1γ→π0π+,−channel.In fact,the curves show intensities2-3times higher than the data,and are20-30MeV downward peaked with respect to the experimental distributions. Regardless of theππreaction channel,the mass distributions of Ref.[21]depict nearly the same threshold behavior,exactly where the effects of medium modification are experimen-tally observed.In order to account for such effects onππdata,a model calculation mustsimultaneously explain the threshold behavior of the I=0(σ)distributions as well as the I=1 (non-resonant)distributions.In this regard,the TAPS results are better predicted by the Valencia model(Fig.4of Ref.[21]),which relates the peak shift of theππinvariant mass distributions to the in-medium modification of theππcorrelation.A general conclusion of this article is that to clearly probe the effects of chiral symmetry restoration,it is advisable to use the composite ratio C Aππ;in fact,this observable yields macroscopic threshold effects when comparing I=0to I=1or2isospin states,and it is nearly independent of the detector acceptance.ACKNOWLEDGMENTSThe present work was supported by the Istituto Nazionale di Fisica Nucleare(INFN) of Italy,the National Science and Engineering Research Council(NSERC)of Canada,the Australian Research Council and the German Ministry of Education and Research.The authors acknowledge the support received from TRIUMF.The authors would also like to acknowledge useful discussions with T.Kunihiro,P.Schuck and M.Vicente-Vacas.References[1]D.Jido,T.Hatsuda and T.Kunihiro,Phys.Rev.D63(2000)011901;T.Hatsuda,T.Kunihiro and H.Shimizu,Phys.Rev.Lett.63(1999)2840.[2]Z.Aouissat,G.Chanfray,P.Schuck,and J.Wambach,Phys.Rev.C61(2000)012202;R.Rapp,J.W.Durso,Z.Aouissat G.Chanfray,O.Krehl,P.Schuck J.Speth and J.Wambach,Phys.Rev.C59(1999)R1237.[3]D.Davesne.Y.J.Zhang and G.Chanfray,Phys.Rev.C62(2000)024604.[4]G.Chanfray,Nucl.Phys.A721(2003)76c;G.Chanfray and M.Ericson,arXiv:nucl-th/0406003.[5]M.J.Vicente-Vacas and E.Oset,Phys.Rev.C60(1999)064621.[6]Particle Data Group,S.Spanier and N.A.T¨o rnqvist,Phys.Rev.D66(2002)010001.[7]S.Prakhov et al.,Phys.Rev.C69(2004)045202.[8]J.M.Link,Phys.Lett.B585(2004)200.[9]M.Ishida,Progress of Theoretical Physics Supplement,149(2003)190.[10]M.Kermani et al.,Phys.Rev.C58(1998)3431.[11]F.Bonutti et al.,Nucl.Phys.A677(2000)213.[12]P.Camerini et al.Nucl.Phys.A735(2004)89.[13]F.Bonutti et al.,Phys.Rev.C55(1997)2998.[14]T.Ericson and W.Weise,Pions and Nuclei,Clarendon Press-Oxford,1988;[15]J.H¨uffner and M.Thies,Phys.Rev.C20(1979)273.[16]J.G.Messchendorp et al.,Phys.Rev.Lett.89(2002)222302.[17]G.R.Smith et al.,Nucl.Instr.and Meth.in Phys.Res.A362(1995)349.[18]H.C.Chiang,E.Oset and M.J.Vicente-Vacas,Nucl.Phys.A644(1998)77.[19]D.Lohse,J.W.Durso,K.Olinde and J.Speth,Phys.Lett.B234(1990)235.[20]M.J.Vicente-Vacas,private communication.[21]P.M¨u hlich,L.Alvarez-Russo,O.Buss and U.Mosel,Phys.Lett.B595(2004)216.。