Boron-doped Ketjenblack based high performances ca

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普罗布考抗动脉粥样硬化作用机制及研究进展

氧化作用主要表现在以下几个方面：①泡沫细胞的
形成是ＡＳ进程中最重要的病理学标志，ｏｘ—ＬＤＬ易被巨噬细胞表面的清道夫受体识别、摄取并降解，促使泡沫细胞形成。普罗布考可有效抑制ＬＤＬ氧化形成ｏｘ．ＬＤＬ，抑制ｏｘ—ＬＤＬ引起的单核细胞黏附和迁移。研究证实，普罗布考在体内外可抑制由ｃｕ“诱导的巨噬细胞脂质氧化，使由巨噬细胞介导的ＬＤＬ氧化降低６８％，同时抑制丙二醛的生成，而且此作用与其浓度成正比¨引。②抑制烟酰胺辅酶氧化酶ＮＡＤ（Ｐ）
摘要：早期大量的药理及临床实验发现，普罗布考具有降低血脂、抗氧化、抗炎等作用，但由于其可降低高密度脂蛋白胆固醇（ＨＤＩ，Ｃ），使其在临床上的应用受到影响。近年的研究证明，普罗布考虽然降低血ＨＤＬ—Ｃ浓度，但并不降低其转运胆固醇酯的作用，甚至增加其转运能力，并可稳定和消退动脉粥样硬化斑块，改善血管内皮功能，减少动脉粥样硬化的发生、发展。现就普罗布考抗动脉粥样硬化作用机制的研究新进展予以综述。关键词：普罗布考；动脉粥样硬化；抗氧化；抗炎症
基金项目：山东省科技发展计划项目（２００ｒ７ＧＧ２０００２０２５）
利于胆固醇逆转运Ｍ】。③ＡＴＰ结合盒转运子Ａｌ
（ＡＢｃＡｌ），又称胆固醇流出调节蛋白，可促进细胞内游离胆固醇及磷酯转运至细胞外，与结合在细胞表
万方数据
・１３９ｌ・
面的载脂蛋白ＡＩ结合形成新生的ＨＤＬ．Ｃ，使外周细胞内脂质降低。普罗布考可明显上调ＡＢＣＡｌ的表达。④卵磷酯胆固醇酰基转移酶，使颗粒表面的游离胆固醇脂化为胆固醇酯，进入颗粒内部，而形成与外周细胞游离胆固醇的浓度差，促进了胆同醇从脂肪组织细胞的流出。普罗布考使卵磷酯胆固醇酰基转移酶活性增强。⑤Ｂ族Ｉ型清道夫受体（ｃｌａｓｓ
ｂｅｃａｕｓｅｉｔ

J. Comput. Chem.

2D Depiction of Nonbonding Interactions forProtein ComplexesPENG ZHOU,1FEIFEI TIAN,2ZHICAI SHANG11Institute of Molecular Design&Molecular Thermodynamics,Department of Chemistry,Zhejiang University,Hangzhou310027,China2College of Bioengineering,Chongqing University,Chongqing400044,ChinaReceived7May2008;Revised25June2008;Accepted22July2008DOI10.1002/jcc.21109Published online22October2008in Wiley InterScience().Abstract:A program called the2D-GraLab is described for automatically generating schematic representation of nonbonding interactions across the protein binding interfaces.The inputﬁle of this program takes the standard PDB format,and the outputs are two-dimensional PostScript diagrams giving intuitive and informative description of the protein–protein interactions and their energetics properties,including hydrogen bond,salt bridge,van der Waals interaction,hydrophobic contact,p–p stacking,disulﬁde bond,desolvation effect,and loss of conformational en-tropy.To ensure these interaction information are determined accurately and reliably,methods and standalone pro-grams employed in the2D-GraLab are all widely used in the chemistry and biology community.The generated dia-grams allow intuitive visualization of the interaction mode and binding speciﬁcity between two subunits in protein complexes,and by providing information on nonbonding energetics and geometric characteristics,the program offers the possibility of comparing different protein binding proﬁles in a detailed,objective,and quantitative manner.We expect that this2D molecular graphics tool could be useful for the experimentalists and theoreticians interested in protein structure and protein engineering.q2008Wiley Periodicals,Inc.J Comput Chem30:940–951,2009Key words:protein–protein interaction;nonbonding energetics;molecular graphics;PostScript;2D-GraLabIntroductionProtein–protein recognition and association play crucial roles in signal transduction and many other key biological processes. Although numerous studies have addressed protein–protein inter-actions(PPIs),the principles governing PPIs are not fully under-stood.1,2The ready availability of structural data for protein complexes,both from experimental determination,such as by X-ray crystallography,and by theoretical modeling,such as protein docking,has made it necessary toﬁnd ways to easily interpret the results.For that,molecular graphics tools are usually employed to serve this purpose.3Although a large number of software packages are available for visualizing the three-dimen-sional(3D)structures(e.g.PyMOL,4GRASP,5VMD,6etc.)and interaction modes(e.g.MolSurfer,7ProSAT,8PIPSA,9etc.)of biomolecules,the options for producing the schematic two-dimensional(2D)representation of nonbonding interactions for PPIs are very scarce.Nevertheless,a few2D graphics programs were developed to depict protein-small ligand interactions(e.g., LIGPLOT,10PoseView,11MOE,12etc.).These tools,however, are incapable of handling the macromolecular complexes.Some other available tools presenting macromolecular interactions in 2D level mainly include DIMPLOT,10NUCPLOT,13and MON-STER,14etc.Amongst,only the DIMPLOT can be used for aesthetically visualizing the nonbinding interactions of PPIs. However,such a program merely provides a simple description of hydrogen bonds,hydrophobic interactions,and steric clashes across the binding interfaces.In this article,we describe a new molecular graphics tool, called the two-dimensional graphics lab for biosystem interac-tions(2D-GraLab),which adopts the page description language (PDL)to intuitively,exactly,and detailedly reproduce the non-bonding interactions and energetics properties of PPIs in Post-Script page.Here,the following three points are the emphasis of the2D-GraLab:(i)Reliability.To ensure the reliability,the pro-grams and methods employed in2D-GraLab are all widely used in chemistry and biology community;(ii)Comprehensiveness. 2D-GraLab is capable of handling almost all the nonbonding interactions(and even covalent interactions)across binding Additional Supporting Information may be found in the online version of this article.Correspondence to:Z.Shang;e-mail:shangzc@interface of protein complexes,such as hydrogen bond,salt bridge,van der Waals(vdW)interaction,hydrophobic contact, p–p stacking,disulﬁde bond,desolvation effect,and loss of con-formational entropy.The outputted diagrams are diversiform, including individual schematic diagram and summarized sche-matic diagram;(iii)Artistry.We elaborately scheme the layout, color match,and page style for different diagrams,with the goal of producing aesthetically pleasing2D images of PPIs.In addi-tion,2D-GraLab provides a graphical user interface(GUI), which allows users to interact with this program and displays the spatial structure and interfacial feature of protein complexes (see .Fig.S1).Identifying Protein Binding InterfacesAn essential step in understanding the molecular basis of PPIs is the accurate identiﬁcation of interprotein contacts,and based upon that,subsequent works are performed for analysis and lay-out of nonbonding mon methods identifyingprotein–protein binding interfaces include a Voronoi polyhedra-based approach,changes in solvent accessible surface area(D SASA),and various radial cutoffs(e.g.,closest atom,C b,andcentroid,etc.).152D-GraLab allows for the identiﬁcation of pro-tein–protein binding interfaces at residue and atom levels.Identifying Binding Interfaces at Residue LevelAll the identifying interface methods at residue level belong toradial cutoff approach.In the radial cutoff approach,referencepoint is deﬁned in advance for each residue,and the residues areconsidered in contact if their reference points fell within thedeﬁned cutoff ually,the C a,C b,or centroid are usedas reference point.16–18In2D-GraLab,cutoff distance is moreﬂexible:cutoff distance5r A1r B1d,where r A and r B are residue radii and d is set by users(as the default d54A˚,which was suggested by Cootes et al.19).Identifying Binding Interfaces at Atom LevelAt atom level,binding interfaces are identiﬁed using closestatom-based radial cutoff approach20and D SASA-basedapproach.21For the closest atom-based radial cutoff approach,ifthe distance between any two atoms of two residues from differ-ent chains is less than a cutoff value,the residues are consideredin contact;In the D SASA-based approach,the SASA is calcu-lated twice to identify residues involved in a binding interface,once for the monomers and once for the complex,if there is achange in the SASA(D SASA)of a residue when going from themonomers to the dimer form,then it is considered involved inthe binding interface.In2D-GraLab,three manners are provided for visualizing thebinding interfaces,including spatial structure exhibition,residuedistance plot,and residue-pair contact map(see .Figs.S2–S4).Analysis and2D Layout of NonbondingInteractionsThe inputﬁle of2D-GraLab is standard PDB format,and the outputs are two-dimensional PostScriptﬁle giving intuitive and informative representation of the PPIs and their strengths, including hydrogen bond,salt bridge,vdW interaction,desolva-tion effect,ion-pair,side-chain conformational entropy(SCE), etc.The outputs are in two forms as individual schematic dia-gram and summarized schematic diagram.The individual sche-matic diagram is a detailed depiction of each nonbonding proﬁle,whereas the summarized schematic diagram covers all nonbonding interactions and disulﬁde bonds across the binding interface.To produce the aesthetically high quality layouts,which pos-sess reliable and accurate parameters,several widely used pro-grams listed in Table1are employed in2D-GraLab to perform the core calculations and analysis of different nonbonding inter-actions.2D-GraLab carries out prechecking procedure for pro-tein structures and warns the structural errors,but not providing revision and reﬁnement functions.Therefore,prior to2D-GraLab analysis,protein structures are strongly suggested to be prepro-cessed by programs such as PROCHECK(structure valida-tion),27Scwrl3(side-chain repair),28and X-PLOR(structure reﬁnement).29Individual Schematic DiagramHydrogen BondThe program we use for analyzing hydrogen bonds across bind-ing interfaces is HBplus,23which calculates all possible posi-tions for hydrogen atoms attached to donor atoms which satisfy speciﬁed geometrical criteria with acceptor atoms in the vicinity. In2D-GraLab,users can freely select desired hydrogen bonds involving N,O,and/or S atoms.Besides,the water-mediated hydrogen bond is also given consideration.Bond strength of conventional hydrogen bonds(except those of water-mediated Table1.Standalone Programs Employed in2D-GraLab.Program FunctionReduce v3.0322Adding hydrogen atoms for proteinsHBplus v3.1523Identifying hydrogen bonds and calculatingtheir geometric parametersProbe v2.1224Identifying steric contacts and clashes at atomlevelMSMS v2.6125Calculating SASA values of protein atoms andresiduesDelphi v4.026Calculating Coulombic energy and reactionﬁeld energy,determining electrostatic energyof ion-pairsDIMPLOT v4.110Providing application programming interface,users can directly set and executeDIMPLOT in the2D-GraLab GUI9412D Depiction of Nonbonding Interactions for Protein ComplexesFigure1.(a)Schematic representation of a conventional hydrogen bond and a water-mediated hydro-gen bond across the binding interface of IGFBP/IGF complex(PDB entry:2dsr).This diagram was produced using2D-Gralab.The conventional hydrogen bond is formed between the atom N(at the backbone of residue Leu69in chain B)and the atom OE1(at the side-chain of residue Glu3in chain I);The water-mediated hydrogen bond is formed between the atom ND1(at the side-chain of residue His5in chain B)and the atom O(at the backbone of residue Asp20in chain I),and because hydrogen positions of water are almost never known in the PDBﬁle,the water molecule,when serving as hydrogen bond donor,is not yet determined for its H...A length and D—H...A angle,denoted as mark ‘‘????.’’In this diagram,chains,residues,and atoms are labeled according to the PDB format.(b)Spa-tial conformation of the conventional hydrogen bond.(c)Spatial conformation of the water-mediated hydrogen bond.hydrogen bonds)is calculated using Lennard-Jones 8-6potential with angle weighting.30D U HB¼E m 3d m 8À4d m6"#cos 4h ðh >90 Þ(1)where d is the separation between the heavy acceptor atom andthe donor hydrogen atom in angstroms;E m ,the optimum hydro-gen-bond energy for the particular hydrogen-bonding atoms con-sidered;d m ,the optimum hydrogen-bond length for the particu-lar hydrogen-bonding atoms considered.E m and d m vary accord-ing to the chemical type of the hydrogen-bonding atoms.The hydrogen bond potential is set to zero when angle h 908.31Hydrogen bond parameters are taken from CHARMM force ﬁeld (for N and O atoms)and Autodock (for S atom).32,33Figure 1a is the schematic representation of a conventional hydrogen bond and a water-mediated hydrogen bond across the binding interface of insulin-like growth factor-binding protein (IGFBP)/insulin-like growth factor (IGF)complex.In this dia-gram,abundant information about the hydrogen bond geometry and energetics properties is presented in a readily acceptant manner.Figures 1b and 1c are spatial conformations of the cor-responding conventional hydrogen bond and water-mediated hydrogen bond.Van der Waals InteractionThe small-probe approach developed in Richardson’s laboratory enables us to detect the all atom contact proﬁle in protein pack-ing.2D-GraLab uses program Probe 24to realize this method to identity steric contacts and clashes on the binding interfaces.Word et al.pointed out that explicit hydrogen atoms can effec-tively improve Probe’s performance.24However,considering calculations with explicit hydrogen atoms are time-consuming,and implicit hydrogen mode is also possibly used in some cases;therefore,in 2D-GraLab,both explicit and implicit hydrogen modes are provided for users.In addition,2D-GraLab uses the Reduce 22to add hydrogen atoms for proteins,and this programis also developed in Richardson’s laboratory and can be wellcompatible with Probe.According to previous deﬁnition,vdW interaction between two adjacent atoms is classiﬁed into wide contact,close contact,small overlap,and bad overlap.24Typically,vdW potential function has two terms,a repulsive term and an attractive term.In 2D-GraLab,vdW interaction is expressed as Lennard-Jones 12-6potential.34D U SI ¼E m d m d 12À2d md6"#(2)where E m is the Lennard-Jones well depth;d m is the distance at the Lennard-Jones minimum,and d is the distance between two atoms.The Lennard-Jones parameters between pairs of different atom types are obtained from the Lorentz–Berthelodt combina-tion rules.35Atomic Lennard-Jones parameters are taken from Probe and AMBER force ﬁeld.24,36Figure 2a was produced using 2D-GraLab and gives a sche-matic representation of steric contacts and clashes (overlaps)between the heavy chain residue Tyr131and two light chain res-idues Ser121and Gln124of cross-reaction complex FAB (the antibody fragment of hen egg lysozyme).By this diagram,we can obtain the detail about the local vdW interactions around the residue Tyr131.In contrast,such information is inaccessible in the 3D structural ﬁgure (Fig.2b).Desolvation EffectIn 2D-GraLab,program MSMS 25is used to calculate the SASA values of interfacial residues at atom level,and four atomic radii sets are provided for calculating the SASA,including Bondi64,Chothia75,Li98,and CHARMM83.32,37–39Bondi64is based on contact distances in crystals of small molecules;Chothia75is based on contact distances in crystals of amino acids;Li98is derived from 1169high-resolution protein crystal structures;CHARMM83is the atomic radii set of CHARMM force ﬁeld.Desolvation free energy of interfacial residues is calculated using empirical additive model proposed by Eisenberg andFigure 2.(a)Schematic representation of steric contacts and overlaps between the residue Tyr131in heavy chain (chain H)and the surrounding residues Ser121and Gln124in light chain (chain L)of cross-reaction complex FAB (PDB entry:1fbi).This diagram was produced using 2D-Gralab in explicit hydrogen mode.In this diagram,interface is denoted by the broken line;Wide contact,close contact,small overlap,and bad overlap are marked by blue circle,green triangle,yellow square,and pink rhombus,respectively;Moreover,vdW potential of each atom-pair is given in the histogram,with the value measured by energy scale,and the red and blue indicate favorable (D U \0)and unfav-orable (D U [0)contributions to the binding,respectively;Interaction potential 20.324kcal/mol in the center circle denotes the total vdW contribution by residue Tyr131;Chains,residues,and heavy atoms are labeled according to the PDB format,and hydrogen atoms are labeled in Reduce format.(b)Spatial conformation of chain H residue Tyr131and its local environment.Green or yellow stands forgood contacts (green for close contact and yellow for slight overlaps \0.2A˚),blue for wide contacts [0.25A˚,hot pink spikes for bad overlaps !0.4A ˚.It is revealed that Tyr131is in an intensive clash with chain L Gln124,while in slight contact with chain L Ser121,which is well consistent with the 2D schematic diagram.9432D Depiction of Nonbonding Interactions for Protein Complexes944Zhou,Tian,and Shang•Vol.30,No.6•Journal of Computational ChemistryFigure2.(Legend on page943.)Maclachlam,40and the conformation of interfacial residues is assumed to be invariant during the binding process.D G dslv¼Xic i D A i(3)where the sum is over all the atoms;c i and D A i are the atomic solvation parameter(ASP)and the changes in solvent accessible surface area(D SASA)of atom i,respectively.Juffer et al.41 found that although desolvation free energies calculated from different ASP sets are linear correlation to each other,the abso-lute values are greatly different.In view of that,2D-GraLab pro-vides four ASP sets published in different periods:Eisenberg86, Kim90,Schiffer93,and Zhou02.40,42–44As shown in Figure3,the D SASA and desolvation free energy of interfacial residues in chain A of HLA-A*0201pro-tein complex during the binding process are reproduced in a rotiform diagram form using2D-GraLab.In this diagram,the desolvation free energy contributed by chain A is28.056kcal/ mol,and moreover,the D SASA value of each interfacial residue is also presented clearly.Ion-PairThere are six types of residue-pairs in the ion-pairs:Lys-Asp, Lys-Glu,Arg-Asp,Arg-Glu,His-Asp,and ually,ion-pairs include three kinds:salt bridge,NÀÀO bridge,and longer-range ion-pair,and found that most of the salt bridges are stabi-lizing toward proteins;the majority of NÀÀO bridges are stabi-lizing;the majority of the longer-range ion-pairs are destabiliz-ing toward the proteins.45The salt bridge can be further distin-guished as hydrogen-bonded salt bridge(HB-salt bridge)and nonhydrogen-bonded salt bridge(NHB-salt bridge or salt bridge).46In2D-GraLab,the longer-range ion-pair is neglected, and for short-range ion-pair,four kinds are deﬁned:HB-salt bridge,NHB-salt bridge or salt bridge,hydrogen-bonded NÀÀO bridge(HB-NÀÀO bridge),and nonhydrogen-bonded N-O bridge (NHB-NÀÀO bridge or NÀÀO bridge).Although both the N-terminal and C-terminal residues of a given protein are also charged,the large degree ofﬂexibility usually experienced by the ends of a chain and the poor structural resolution resulting from it.47Therefore,we preclude these terminal residues in the 2D-GraLab.A modiﬁed Hendsch–Tidor’s method is used for calculating association energy of ion-pairs across binding interfaces.48D G assoc¼D G dslvþD G brd(4)where D G dslv represents the sum of the unfavorable desolvation penalties incurred by the individual ion-pairing residues due to the change in their environment from a high dielectric solvent (water)in the unassociated state;D G brd represents the favorable bridge energy due to the electrostatic interaction of the side-chain charged groups.We usedﬁnite difference solutions to the linearized Poisson–Boltzmann equations in Delphi26to calculate the D G dslv and D G brd.Centroid of the ion-pair system is used as grid center,with temperature of298.15K(in this way,1kT50.593kcal/mol),and the Debye-Huckel boundary conditions are applied.49Considering atomic parameter sets have a great inﬂu-ence on the continuum electrostatic calculations of ion-pair asso-ciation energy,502D-GraLab provides three classical atomic parameter sets for users,including PARSE,AMBER,and CHARMM.51–53Figure4is the schematic representation of four ion-pairs formed across the binding interface of penicillin acylase enzyme complex.This diagram clearly illustrates the information about the geometries and energetics properties of ion-pairs,such as bond length,centroid distance,association energy,and angle. The ion-pair angle is deﬁned as the angle between two unit vec-tors,and each unit vector joins a C a atom and a side-chain charged group centroid in an ion-pairing residue.54In this dia-gram,the four ion-pairs,two HB-salt bridges,and two HB-NÀÀO bridges formed across the binding interface are given out. Association energies of the HB-salt bridges are both\21.5 kcal/mol,whereas that of the HB-NÀÀO bridges are all[20.5 kcal/mol.Therefore,it is believed that HB-salt bridge is more stable than HB-NÀÀO bridge,which is well consistent with the conclusion of Kumar and Nussinov.45,46Side-Chain Conformational EntropyIn general,SCE can be divided into the vibrational and the con-formational.55Comparison of several sets of results using differ-ent techniques shows that during protein folding process,the mean conformational free energy change(T D S)is1kcal/mol per side-chain or0.5kcal/mol per bond.Changes in vibrational entropy appear to be negligible compared with the entropy change resulted from the loss of accessible rotamers.56SCE(S) can be calculated quite simply using Boltzmann’s formulation.57S¼ÀRXip i ln p i(5)where R is the universal gas constant;The sum is taken over all conformational states of the system and p i is the probability of being in state i.Typical methods used for SCE calculations, include self-consistent meanﬁeld theory,58molecular dynam-ics,59Monte Carlo simulation,60etc.,that are all time-consum-ing,thus not suitable for2D-GraLab.For that,the case is sim-pliﬁed,when we calculate the SCE of an interfacial residue,its local surrounding isﬁxed(adopting crystal conformation).In this way,SCE of each interfacial residue is calculated in turn.For the20coded amino acids,Gly,Ala,Pro,and Cys in disulﬁde bonds are excluded.57For other cases,each residue’s side-chain conformation is modeled as a rotamer withﬁnite number of discrete states.61The penultimate rotamer library used was developed by Lovell et al.,62as recommended by Dun-brack for the study of SCE.63For an interfacial residue,the potential E i of each rotamer i is calculated in both binding state and unbinding state,and subsequently,rotamer’s probability dis-tribution(p)of this residue is resulted by Boltzmann’s distribu-tion law,then the SCE in different states are solved out using eq.(5).The situation of rotamer i is deﬁned as serious clash or nonclash:serious clash is the clash score of rotamer i more than a given threshold value,and then E i511;whereas for the9452D Depiction of Nonbonding Interactions for Protein Complexes946Zhou,Tian,and Shang•Vol.30,No.6•Journal of Computational ChemistryFigure3.Schematic representation of desolvation effect for interfacial residues in chain A of HLA-A*0201complex(PDB entry:1duz).This diagram was produced using2D-GraLab.In this diagram,the pie chart is equally divided,with each section indicates an interfacial residue in chain A;In a sec-tor,red1blue is the SASA of corresponding residue in unbinding state,the blue is in binding state,and the red is thus of D SASA;The green polygonal line is made by linking desolvation free energy ofeach interfacial residue,and at the purple circle,desolvation free energy is0(D U50),beyond thiscircle indicates unfavorable contributions to binding(D U[0),otherwise is favorable(D U\0);Inthe periphery,residue symbols are colored in red,blue,and black in terms of favorable,unfavorable,and neutral contributions to the binding,respectively;The SASA and desolvation free energy for eachinterfacial residue can be measured qualitatively by the horizontally black and green scales.[Colorﬁgure can be viewed in the online issue,which is available at .]Figure4.Four ion-pairs formed across the binding interface of penicillin acylase enzyme complex (PDB entry:1gkf).In thisﬁgure,left is2D schematic diagram produced using2D-GraLab,and posi-tively and negatively charged residues are colored in blue and red,respectively;Bridge-bonds formed between the charged atoms of ion-pairs are colored in green,blue,and yellow dashed lines for the hydrogen-bonded bridge,nonhydrogen-bonded bridge,and long-range interactions,respectively;The three parameters in bracket are ion-pair type,angle,and association energy.The right in thisﬁgure is the spatial conformations of corresponding ion-pairs.[Colorﬁgure can be viewed in the online issue, which is available at .]Figure5.(a)Loss of side-chain conformational entropy of chain B interfacial residues in HIV-1 reverse transcriptase complex(PDB entry:1rt1).This diagram was produced using2D-GraLab.In this diagram,the pie chart is equally divided,with each section indicates an interfacial residue in chain B; In a sector,side-chain conformational entropies in unbinding and binding state are colored in yellow and blue,respectively;The green polygonal line is made by linking conformational free energy of each interfacial residue;The conformational entropy and conformational free energy for each interfa-cial residue can be measured qualitatively by the horizontally black and green scales,respectively;In the periphery,residue symbols are colored in yellow,blue,and black in terms of favorable,unfavora-ble,and neutral contributions to binding,respectively.(b)The rotamers of chain B interfacial residues Lys20,Lys22,Tyr56,Asn136,Ile393,and Trp401in HIV-1reverse transcriptase complex.These rotamers were generated using2D-GraLab.[Colorﬁgure can be viewed in the online issue,which is available at .]9472D Depiction of Nonbonding Interactions for Protein Complexes948Zhou,Tian,and Shang•Vol.30,No.6•Journal of Computational ChemistryFigure5.(Legend on page947.)Figure6.The summarized schematic diagram of nonbonding interactions and disulﬁde bond across the interface of AIV hemagglutinin H5complex(PDB entry:1jsm).Length of chain A and chain B are321and160,represented as two bold horizontal lines.Interface parts in the bold lines are colored in orange,and residue-pairs in interactions are linearly linked;Conventional hydrogen bond,water-mediated hydrogen bond,ionpair,hydrophobic force,steric clash,p–p stacking,and disulﬁde bond are colored in aqua,bottle green,red,blue,purple,yellow,and brown,respectively;In the‘‘dumbbell shape’’symbols,residue-pair types and distances are also presented.[Colorﬁgure can be viewed in the online issue,which is available at .]9492D Depiction of Nonbonding Interactions for Protein Complexescase of nonclash,four potential functions are used in2D-Gra-Lab:(i)E i5E0,a constant61;(ii)statistical potential,the poten-tial energy E i of rotamer i is calculated from database-derived probability61;(iii)coarse-grained model,E i of rotamer i is esti-mated by atomic contact energies(ACE)64;and(iv)Lennard-Jones potential.58Loss of binding entropy of chain B interfacial residues in HIV-1reverse transcriptase complex is schematically repre-sented in Figure5a.Similar to desolvation effect diagram,loss of binding entropy is also presented in a rotiform diagram form. This diagram reveals that during the process of forming HIV-1 reverse transcriptase complex,the total loss of conformational free energy of chain B is9.14kcal/mol,indicating a strongly unfavorable contribution to binding(D G[0),and the average loss of conformational free energy for each residue is about0.3 kcal/mol,much less than those in protein folding(about1kcal/ mol56).Figure5b shows the rotamers of six interfacial residues in chain B.Summarized Schematic DiagramFigure6illustrates nonbonding interactions and disulﬁde bond formed across the binding interface of avian inﬂuenza virus (AIV)hemagglutinin H5.This protein is a dimer linked by a disulﬁde bond.In this diagram,conventional hydrogen bond, water-mediated hydrogen bond,ion-pair,hydrophobic force, steric clash,p–p stacking,and disulﬁde bond are represented in different colors.Hydrogen bonds,colored in aqua,are calculated by program HBplus.23Data in this diagram are the separation between the acceptor atom and the heavy donor atom.Water-mediated hydrogen bonds are colored in bottle green, also calculated by HBplus.23Ion-pairs,colored in red,include salt bridge and NÀÀO bridge,determined by the Kumar’s rule.45,46Data in this dia-gram are centroid distance of ion-pair.Hydrophobic forces are colored in blue.According to the D SASA rule,if the two apolar and/or aromatic interfacial resi-dues(Leu,Ala,Val,Ile,Met,Cys,Pro,Tyr,Phe,and Trp)are within the distance d\r A1r B12.8(r A and r B are side-chain radii,2.8is the diameter of water molecule),they are considered in hydrophobic contact.Data in this diagram are centroid–cent-roid separation between the two residues.Steric clashes are colored in purple.Here,only bad overlaps calculated by Probe24are presented.In2D-GraLab,explicit and implicit hydrogen modes are provided,hydrogen atoms in explicit hydrogern mode are added using Reduce.22Data in this diagram are the centroid–centroid separation when the two atoms are badly overlapped.p–p stacking are colored in yellow.Presently,studies on pro-tein stacking interactions are in lack.In2D-GraLab,p–p stack-ing is identiﬁed using the McGaughey’s rule,65i.e.,if the cent-roid–centroid separation between two aromatic rings is within 7.5A˚,they are regarded as p–p stacking(aromatic residues are Phe,Tyr,Trp,and His).This rule has been successfully adopted to study the p–p stacking across protein interfaces by Cho et al.66Besides,2D-GraLab also sets the constraints of stacking angle(dihedral angel between the planes of two aromatic rings).Data in this diagram are centroid–centroid separations between two aromatic rings in stacking state.Disulﬁde bonds are colored in brown,taken from the PDB records.Data in this diagram are the separations of two sulﬁde atoms.ConclusionsMost,if not all,biological processes are regulated through asso-ciation and dissociation of protein molecules and essentially controlled by nonbonding energetics.67Graphically-intuitive vis-ualization of these nonbonding interactions is an important approach for understanding the mechanism of a complex formed between two proteins.Although a large number of software packages are available for visualizing the3D structures,the options for producing schematic2D summaries of nonbonding interactions for a protein complex are comparatively few.In practice,the2D and3D visualization methods are complemen-tary.In this article,we have described a new2D molecular graphics tool for analyzing and visualizing PPIs from spatial structures,and the intended goal is to schematically present the nonbonding interactions stabilizing the macromolecular complex in a graphically-intuitive manner.We anticipate that renewed in-terest in automated generation of2D diagrams will signiﬁcantly reduce the burden of protein structure analysis and make insights into the mechanism of PPIs.2D-GraLab is written in C11and OpenGL,and the output-ted2D schematic diagrams of nonbinding interactions are described in PostScript.Presently,2D-GraLab v1.0is available to academic users free of charge by contacting us. References1.Chothia,C.;Janin,J.Nature1974,256,705.2.Jones,S.;Thornton,J.M.Proc Natl Acad Sci USA1996,93,13.3.Luscombe,N.M.;Laskowski,R.A.;Westhead,D.R.;Milburn,D.;Jones,S.;Karmirantzoua,M.;Thornton,J.M.Acta Crystallogr D 1998,54,1132.4.DeLano,W.L.The PyMOL Molecular Graphics System;DeLanoScientiﬁc:San Carlos,CA,2002.5.Petrey,D.;Honig,B.Methods Enzymol2003,374,492.6.Humphrey,W.;Dalke,A.;Schulten,K.J Mol Graphics1996,14,33.7.Gabdoulline,R.R.;Wade,R.C.;Walther,D.Nucleic Acids Res2003,31,3349.8.Gabdoulline,R.R.;Hoffmann,R.;Leitner,F.;Wade,R.C.Bioin-formatics2003,19,1723.9.Wade,R. C.;Gabdoulline,R.R.;De Rienzo, F.Int J QuantumChem2001,83,122.10.Wallace, A. C.;Laskowski,R. A.;Thornton,J.M.Protein Eng1995,8,127.11.Stierand,K.;Maaß,P.C.;Rarey,M.Bioinformatics2006,22,1710.12.Clark,A.M.;Labute,P.J Chem Inf Model2007,47,1933.13.Luscombe,N.M.;Laskowski,R. A.;Thorntonm J.M.NucleicAcids Res1997,25,4940.14.Salerno,W.J.;Seaver,S.M.;Armstrong,B.R.;Radhakrishnan,I.Nucleic Acids Res2004,32,W566.15.Fischer,T.B.;Holmes,J.B.;Miller,I.R.;Parsons,J.R.;Tung,L.;Hu,J.C.;Tsai,J.J Struct Biol2006,153,103.950Zhou,Tian,and Shang•Vol.30,No.6•Journal of Computational Chemistry。

舍维尼玛科宝

Revised 07/2023 Issue 1HIGH SOLIDS, SURFACE-TOLERANT EPOXY PRIMER A 2-pack epoxy primer coat for steel and galvanized surfaces.Economically and high-performance corrosion protection also for manually prepared surfaces and surfaces prepared by high-pressure water jetting. Low solvent content according to Protective Coatings Directive of German Paint Industry Association (VdL-RL 04).▪ Surface tolerant▪ H igh film thickness and diffusion resistance combined with very good surface wetting properties and adhesion result in a very high safety margin for good corrosion protection▪ Fast initial drying and full curing▪ High build application▪ Very economical due to high volume solidsCan be used as a robust versatile overcoatable primer for corrosion protection on steel exposed to atmosphere. 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Any reduction must be compliant with existing VOC regulations and compatible with the existing environmental and application conditions.Airless SprayUnit: Efficient airless equipmentTip Size: 0.38 – 0.53 mm (0.015 – 0.021 inch)Fan Angle: 40° - 80°Operating Pressure: min. 180 bar (2600 psi)Spray hoses: Ø ⅜ inch (10 mm), max. 20 m+ 2 m with reduced Ø of ¼ inch (6 mm)The airless spray details given above are intended as a guide only.Details such as fluid hose length and diameter, paint temperature and job shape and size all have an effect on the spray tip and operating pressure chosen. However, the operating pressure should be the lowest possible consistent satisfactory atomisation.As conditions will vary from job to job, it is the applicators responsibility to ensure that the equipment in use has been set up to give the best results.If in doubt consult Sherwin-Williams customer service.Conventional SprayAtomising Pressure: 3 - 5 bar (43 - 73 psi)Tip Size: 1.5 – 2.5 mm (0.06 – 0.10 inch)Brush and Roller• Surface preparation St 2 or St 3• With brush application best penetration and surface wetting is achievedRevised 07/2023 Issue 1HIGH SOLIDS, SURFACE-TOLERANT EPOXY PRIMERSteel resp. patch up of spots on hot-dip galvanized surfaces 2 x Macropoxy ® Primer HE NOvercoatable with 1- and 2-pack coatings e.g Macropoxy ®, Acrolon ® and Kem Kromik ®, provided the surface to be coated is clean, dry and free from contamination.Example Blatt 941 x Macropoxy ® Primer HE N 1 x Macropoxy ® EG-1 VHS1 x Acrolon ® EG-4 or Acrolon ® EG-5Old coatingsMacropoxy ® Primer HE N can be used on a variety of sound 1-pack and 2-pack coats for refurbishment.Note: Macropoxy ® Primer HE N is not recommended for permanentimmersion.Drying times, curing times and pot life should be considered as a guide only.Epoxy Coatings - Tropical UseEpoxy coatings at the time of mixing should not exceed a temperature of 35ºC. 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具有烷基磺酸侧链的凝胶型聚苯并咪唑质子交换膜的制备与表征

化工进展Chemical Industry and Engineering Progress2024 年第 43 卷第 4 期具有烷基磺酸侧链的凝胶型聚苯并咪唑质子交换膜的制备与表征朱泰忠1，张良1，黄泽权1，罗伶萍1，黄菲1，薛立新1，2（1 浙江工业大学化工学院膜分离与水科学技术中心，浙江杭州 310014；2温州大学化学与材料工程学院，浙江温州 325035）摘要：磷酸（PA ）掺杂聚苯并咪唑（PBI ）以其优异的热化学稳定性和高玻璃化转变温度成为高温质子交换膜燃料电池（HT-PEMFCs ）的首选材料。

然而，由于低温下磷酸较弱的解离度和传递速率，导致膜的质子传导性能不佳，电池冷启动困难。

因此，研发可在宽温湿度范围内高效运行的高温质子交换膜成为当前挑战。

特别是拓宽其低温运行窗口、实现冷启动对这类质子交换膜燃料电池在新能源汽车领域的实际应用具有重要意义。

本文通过多聚磷酸溶胶凝胶工艺与内酯开环反应设计并合成了一系列磷酸掺杂的具有柔性烷基磺酸侧链的凝胶型聚苯并咪唑质子交换膜。

重点探究了烷基磺酸的引入以及侧链长度对磷酸掺杂水平、不同温湿度下的质子传导率及稳定性的影响规律。

研究结果表明，所制备的质子交换膜具有凝胶型自组装片层堆叠的多孔结构，有利于吸收大量磷酸并提供质子快速传输通道。

其中，PA/PS-PBI 展现出了在宽温域范围内均优于目前所报道的其他工作的质子传导性能。

特别是常温下，其质子传导率从原膜的0.0286S/cm 提升至0.0694S/cm 。

80℃下，其质子传导率从原膜的0.1117S/cm 提升至0.1619S/cm 。

200℃下，其质子传导率从原膜的0.2609S/cm 提升至0.3578S/cm 。

此外，该膜在80℃和0%相对湿度（RH ）条件下仍可具有与Nafion 膜在100%RH 时相当的质子传导率，为打破质子交换膜经典定义、实现宽温域（25~240℃）运行提供新的方案。

卟啉化合物的合成

第 19 卷第 4 期 2007 年 4 月
化学进展
PROGRESS IN CHEMISTRY
Vol . 19 No. 4 Apr. , 2007
卟啉化合物的合成 3
王周锋邓文礼 3 3
(华南理工大学材料科学与工程学院广州 510640)
摘要卟啉化合物在自然界中广泛存在 ,它作为辅基普遍存在于血色素、肌球素、细胞色素、接触酶素、过氧物酶、叶绿素和细胞叶绿素中。本文主要介绍吡咯与醛酮缩合环化合成卟啉化合物的两种方法 :吡咯与醛酮直接缩合环化法和模块法 ,分别论述近年来四苯基卟啉型 ( meso2取代) 和八乙基卟啉型 (β2取代) 合成方面的研究进展。对模块法中模块单体的合成制备给予较为详细的介绍。
© 1994-2007 China Academic Journal Electronic Publishing House. All rights reserved.
第4期
王周锋等卟啉化合物的合成
·521 ·
图 1 不同种类的卟啉化合物 Fig. 1 Different kinds of porphyrins
收稿 : 2006 年 5 月 , 收修改稿 : 2006 年 6 月 3 国家自然科学基金项目 (No. 20643001) 资助 3 3 通讯联系人 e2mail :wldeng @scut. edu. cn
发展非常迅速 ,关于卟啉的著名专著就有 Porphyrins and Metalloporphyrins [3 , 4] 、The Porphyrin Handbook [5] 和 The Porphyrins[6] 等。在过去的二十年间 ,卟啉化学经历了一个飞速发展阶段 ,其主要的突破口就是卟啉类化合物种类的增多和合成方法的改进。

十二烷基磺酸钠所致外切葡聚糖纤维二糖水解酶底物专一性的变化

十二烷基磺酸钠所致外切葡聚糖纤维二糖水解酶底物专一性的
变化
阎伯旭;高培基
【期刊名称】《纤维素科学与技术》
【年(卷),期】1998(006)003
【摘要】以低浓度的十二烷基磺酸钠（ＳＤＳ）为微扰剂处理外切葡聚糖纤维二糖水解酶（ＣＢＨＩ），由荣光、圆二和二阶导数谱测定反应动力学常数。

结果表明低浓度的ＳＤＳ自理可显著增加ＣＢＨＩ的内切酶活力，推测是ＣＢＨＩ活性位点附近的色氨酸所处微环境发生了变化，影响了酶与纤维素的结合所致。

对近年来在分子水平上研究纤维素酶底物专一性的结果作了评述。

【总页数】6页(P10-15)
【作者】阎伯旭;高培基
【作者单位】山东大学微生物技术国家重点实验室;山东大学微生物技术国家重点实验室
【正文语种】中文
【中图分类】Q556.2
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果胶与多酚相互作用机制及其对食品加工特性影响的研究进展

张璇，赵文，高哲，等. 果胶与多酚相互作用机制及其对食品加工特性影响的研究进展[J]. 食品工业科技，2024，45（1）：378−386.doi: 10.13386/j.issn1002-0306.2023030201ZHANG Xuan, ZHAO Wen, GAO Zhe, et al. Research Progress on the Interaction Mechanism of Pectin and Polyphenol and Their Effect on Food Processing Characteristics[J]. Science and Technology of Food Industry, 2024, 45(1): 378−386. (in Chinese with English abstract). doi: 10.13386/j.issn1002-0306.2023030201· 专题综述 ·果胶与多酚相互作用机制及其对食品加工特性影响的研究进展张　璇1，赵　文1,2，高　哲1，李美娇1，吴梦颖1，周　茜1,*（1.河北农业大学食品科技学院，河北保定 071000；2.河北省农产品加工工程技术研究中心，河北保定 071000）摘　要：果胶和多酚共存于植物性食品体系中。

除天然存在的果胶-多酚复合物外，在受到加热、高压、干燥等外力作用的食品加工过程中，两者会快速且自发地进行相互作用。

果胶与多酚之间的相互作用会影响食品的理化性质和功能特性。

本文总结了果胶与多酚相互作用的机制、内部和外部多重影响因素、主要的研究方法并结合 Langmuir 和Freundlich 常见的等温吸附模型对果胶与多酚之间的吸附行为进行描述和定量表征。

此外还探讨了两者相互作用对食品加工特性及多酚生物可利用性的影响，分析了该领域的研究方向和发展趋势。

关键词：果胶，多酚，相互作用，等温吸附模型，生物可利用性本文网刊:中图分类号：TS255.1 文献标识码：A 文章编号：1002−0306（2024）01−0378−09DOI: 10.13386/j.issn1002-0306.2023030201Research Progress on the Interaction Mechanism of Pectin and Polyphenol and Their Effect on Food Processing CharacteristicsZHANG Xuan 1，ZHAO Wen 1,2，GAO Zhe 1，LI Meijiao 1，WU Mengying 1，ZHOU Qian 1, *（1.College of Food Science and Technology, Hebei Agricultural University, Baoding 071000, China ；2.Engineering Technology Research Center for Agricultural Product Processing of Hebei, Baoding 071000, China ）Abstract ：The pectin and polyphenols that co-exist in plant-based food systems form complexes in natural conditions and interact quickly and spontaneously during food processing due to external forces, such as heating, high pressure, and drying.The interaction can affect the physicochemical properties and functional properties of foods. This review summarizes the mechanisms, multiple internal and external influencing factors, and main research methods involved in pectin and polyphenol interaction, while their adsorption behavior is described and quantitatively characterized using the isothermal adsorption model commonly used by Langmuir and Freundlich. In addition, the impact of pectin and polyphenol interaction on food processing characteristics and polyphenol bioavailability is also discussed, and the future research prospects and development trends in this field are analyzed.Key words ：pectin ；polyphenol ；interactions ；isothermal adsorption models ；bioavailability果胶是一种酸性杂多糖，广泛存在于蔬菜、水果和谷物等植物细胞壁中，在人类健康中发挥着重要的作用[1]。

聚多巴胺-纳米金修饰玻碳电极检测芦丁

ｃｌａｂｅｈａｖｉｏｒｏｆｒｕｔｉｎａｔｔｈｅｍｏｄｉｉｆｅｄｅｌｅｃｔｒｏｄｅｗａｓｓｔｕｄｉｅｄ，ａｎｄｈｅｔｅｘｐｅｉｍｅｒｎｔｌａｒｅｓｕｌｔｓｉｎｄｉｃａｔｅｄｈａｔｔｔｈｅｐｒｏｐｏｓｅｄｓｅｎｓｏｒｅｘｈｉｂｉｔｓ
ｍｅｔｈｏｄ．Ｔｈｅｓｕｒｆａｃｅｍｏｒｐｈｏｌｏｇｙｏｆｍｄｉｏｉｆｅｄｅｌｅｃｔｒｄｅｏｗａｓｃｈａｒａｃｔｅｒｉｚｅｄｂｙｓｃａｎｎｉｎｇｅｌｅｃｔｒｏｎｍｉｃｒｏｓｃｏｐｙ（ＳＥＭ）．Ｔｈｅｅｌｅｃｔｒｏｃｈｅｍｉ－
Ｄｅｔｅｒｍｉｎａｔｉｏｎｏｆｒｕｔｉｎｂｙｐｏｌｙｄｏｐａｍｉｎｅ－ｎａｎｏＡｕ
ｍｏｄｉｉｅｆｄｇｌａｓｓｙｃａｒｂｏｎｅｌｅｃｔｒｏｄｅ
ＺＨＡＮＧＹｉｎｇ， “
２．ＫｅｙＬａｂｏｒａｔｏｒｙｏｆＧｒｅｅｎＣａｔａｌｙｓｉｓｏｆＳｉｃｈｕｎａＩｎｓｔｉｔｕｔｅｓｏｆＨＪｉｓｈＥｄｕｃａｉｔｏｎ，Ｚｉｇｏｎｇ４３６０００，Ｃｈｉｎａ；
３．ＣｏＨｅｇｅｏｆＭａｔｅｉｒｌｓａａｎｄＣｈｅｍｉｃｌａＥｎｇｉｎｅｅｉｒｎｇ，ＳｉｅｈｕｎａＵｎｉｖｅｓｉｒｙｔｏｆＳｃｉｅｎＣｅｎｄａＥｎｉｇｎｅｅｉｆｎｇ，Ｚｉｇｏｎｇ４３６０００，Ｃｈｉｎａ）

An Energy-Based Excess Pore Pressure Generation Model for cohesionless soils

J.K. Mitchell
University Distinguished Professor, Emeritus, Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, Virginia, USA
1
work, the simplicity and accuracy of their stress-based pore pressure generation model still warrants its use today (e.g. Dickenson & Yang 1998). Alternatively to the stress-based model used by Booker et al. (1976), the authors have developed a single parameter, energy-based pore pressure generation model, denoted as the GMP model. The motivation for the development of this model was to enable the use of dissipated energy as a measure of soil liquefaction resistance and for development of energy based methods for design of ground improvement by soil densification. The GMP model is an empirical relation between dissipated shear energy and the residual excess pore pressure ratio, ru. The GMP model has accurately approximated ru in cyclic triaxial samples, cyclic torsional samples, and large-scale shake table samples consisting of a variety of silt-sand mixtures at various densities. In addition, a preliminary correlation between the GMP model’s single calibration parameter and relative density is presented for Yatesville silt-sand mixtures. A comparison of measured ru values in cyclic triaxial samples with those computed using both the GMP model and the stress-based model used by Booker et al. (1976) shows both models give good results. Because the GMP model has a simple mathematical form and a single calibration parameter, it is easy to implement and calibrate. 2 STRESS-BASED MODEL Two kinds of pore pressures are generated in soils during seismic shaking: transient and residual. In saturated sands, the transient pore pressures are equal to the changes in the applied mean normal stresses during seismic excitation. Accordingly, transient pore pressures have little influence on the effective stresses in the soil. On the other hand, the residual pore pressures that result from plastic deformations in the sand skeleton can exert major influences on the strength and stiffness of the sand (Finn 1988). During stress-controlled cyclic tests, the residual pore pressures are assumed to be those at the time when the applied deviator stress equals (or crosses) zero. By observing the rate of pore pressure development in stress-controlled cyclic tests on sands of various densities, Lee and Albaisa (1974) showed that the rate of excess pore pressure build-up generally falls within a narrow band when plotted in a normalized fashion as shown in Figure 1. In Figure 1, the vertical axis is the residual excess pore ratio, ru = uxs/σ′co, and the horizontal axis is the cycle ratio, N/Nliq; uxs is the residual pore pressure in excess of hydrostatic conditions, σ′co is the initial effective confining stress, N is number of loading cycles in a stress-controlled cyclic test, and Nliq is the number of loading cycles in a stress-controlled cyclic test required to cause initial liquefaction, defined as the point when ru = 1.0. The upper and lower bounds of the observed residual excess pore pressure build-up as a function of the cycle ratio for cohesionless soils are shown as the solid lines in Figure 1. Seed et al. (1975b) developed an empirical expression for ru as a function of cycle ratio. This expression was subsequently simplified by Booker et al. (1976) and is given as Equation 1 below. When θ is set equal to 0.7, Equation 1, shown as the dashed curve in Figure 1, provides a reasonable average of the upper and lower bounds of the observed residual pore pressure generation curves.

复方苁蓉益智胶囊治疗血管性痴呆的研究进展

血管性痴呆（vascular dementia,VD）是一种由脑血管病变导致的疾病，其临床症状包括引起记忆和执行功能障碍等。

它被认为是继阿尔茨海默病之后的第二大常见痴呆类型[1]。

目前，在亚洲和发展中国家的痴呆病例中，VD 约占30%，高于北美和欧洲（15%～20%）[2-3]。

据研究资料显示，我国60岁及以上人群的血管性痴呆发病率为每年每千人中有2.42例[4-5]。

研究表明，我国约有1507万人60岁以上的痴呆患者，其中约有392万人为VD 患者[6]。

VD 会造成日常生活质量不断下降，而且不能扭转，给家庭和社会带来极大的冲击和负担。

复方苁蓉益智胶囊是由王永炎院士多年临床实践研制的具有益智养肝,化浊活血和增智健脑等功效的中成药[7]，主料何首乌、肉苁蓉、荷叶、地龙、漏芦等。

Progress of compound ciYizhi capsule in the treatment of vascular dementia Di Shuai, Zhang Jiapeng, Liu Yixuan, LiYanan, Zhang Jiang, Zhou Fuling. The Affiliated Hospital of North China University of Science and Technology, Tangshan 063000, China【Abstract 】Compound ciYizhi capsule has the effect of nourishing liver,promoting turbidity and activating blood, and increasing wisdom and brain. It is suitable for mild to moderate vascular dementia with liver and kidney deficiency and phlegm stasis blocking collateral syndrome. Recently, it has been widely used in the long-term and synergistic treatment of vascular dementia with remarkable efficacy.To summarizes the clinical and experimental studies of compound ciYizhi capsule. It is found that compound ciYizhi capsule can treat vascular dementia by reducing the expression of MARKS mRNA in hippocampus, inhibiting oxidative stress in brain tissue, protecting mitochondria, reducing the range of cerebral infarction, protecting cerebral ischemic injury and pound ciYizhi capsule combined with other anti-dementia drugs can significantly improve the clinical symptoms of patients with vascular dementia and improve the self-care ability and quality of life.In order to provide some reference for the subsequent study of compound cistanche qianyi capsule.【Key words 】Vascular dementia; Compound ciYizhi capsule; Dementia; Clinical application 复方苁蓉益智胶囊治疗血管性痴呆的研究进展邸帅张佳朋刘乙璇李亚楠张江* 周福玲作者单位：063000 河北省唐山市，华北理工大学附属医院神内二、四病区*通讯作者【摘要】复方苁蓉益智胶囊具有益智养肝,化浊活血和增智健脑的功效，适用于肝肾亏虚兼痰瘀阻络证的轻中度血管性痴呆。

非等位基因

非等位基因概述非等位基因是指同一基因座上的不同等位基因。

等位基因是指在某个给定的基因座上，可以存在多种不同的变体。

每个个体继承了一对等位基因，一对等位基因可能会导致不同的表型表达。

非等位基因的存在使得遗传学研究更加复杂，因为不同的等位基因会对个体的表型产生不同的影响。

背景在生物学中，基因座是指染色体上一个特定的位置，该位置上的基因决定了某个特征的表达方式。

每个基因座上可以有多种不同的等位基因。

等位基因是指在某个特定基因座上的不同基因变体。

每个个体都会继承一对等位基因，通过这对等位基因的不同组合，决定了个体的表型。

然而，并非所有基因座上的等位基因都具有相同的表现型。

非等位基因的影响非等位基因的存在导致不同等位基因会对个体表型产生不同的影响。

有些非等位基因会表现出显性效应，也就是说，当个体继承了一个突变的等位基因时，即使同时继承了一个正常的等位基因，但显性效应会使得突变的等位基因的表型表达得到体现。

相反，有些非等位基因会表现出隐性效应，当个体继承了两个突变的等位基因时，才会表现出突变的表型。

除了显性和隐性效应之外，非等位基因还可能发生两种其他类型的表型效应。

一种是共显效应，当个体继承了两个不同的突变等位基因时，在表型表达上会表现出一种新的特征，这个特征并不是单个突变等位基因所能导致的。

另一种是部分显性效应，当个体继承了两个不同的突变等位基因时，表型表达将介于两个单独突变等位基因的表型之间。

重组和非等位基因重组是指两个不同的染色体交换部分基因序列的过程。

在重组的过程中，非等位基因可能会发生改变，导致新的等位基因组合形成。

这一过程使得非等位基因的表型效应更加复杂，因为新的等位基因可能将不同基因座的效应组合起来。

非等位基因的重要性非等位基因对生物的适应性和多样性起着重要作用。

通过对等位基因的各种组合的研究，人们可以更好地理解基因与表型之间的关系，并揭示遗传变异对物种适应环境的重要性。

总结非等位基因是指同一基因座上的不同等位基因。

介孔聚多巴胺介导催化

介孔聚多巴胺介导催化下载温馨提示：该文档是我店铺精心编制而成，希望大家下载以后，能够帮助大家解决实际的问题。

文档下载后可定制随意修改，请根据实际需要进行相应的调整和使用，谢谢!并且，本店铺为大家提供各种各样类型的实用资料，如教育随笔、日记赏析、句子摘抄、古诗大全、经典美文、话题作文、工作总结、词语解析、文案摘录、其他资料等等，如想了解不同资料格式和写法，敬请关注!Download tips: This document is carefully compiled by the editor. I hope that after you download them, they can help you solve practical problems. The document can be customized and modified after downloading, please adjust and use it according to actual needs, thank you!In addition, our shop provides you with various types of practical materials, suchas educational essays, diary appreciation, sentence excerpts, ancient poems, classic articles, topic composition, work summary, word parsing, copy excerpts, other materials and so on, want to know different data formats and writing methods, please pay attention!标题：介孔聚多巴胺介导催化：新颖纳米材料在催化领域的应用摘要：催化技术一直是化学领域的热点之一，其在环境保护、能源转化等方面发挥着重要作用。

HIGH PRESSURE LOW THERMAL BUDGE HIGH-K POST ANNEAL

专利名称：HIGH PRESSURE LOW THERMAL BUDGEHIGH-K POST ANNEALING PROCESS发明人：Qiuming Huang申请号：US15429194申请日：20170210公开号：US20180175195A1公开日：20180621专利内容由知识产权出版社提供专利附图：摘要：A method of embedding SiGe when fabricating a PMOS device is provided.Multiple layers of SiGe layers with different Ge contents may be formed such that the Ge content increases to from bottom layer(s) to middle layer(s), and decreases from themiddle layer(s) to top layer(s). In some embodiments, the embedded SiGe can have a SiGe seed layer over a substrate, a first SiGe transition layer over the SiGe seed layer, a SiGe milled layer over the first SiGe transition layer, and a second SiGe transition layer over the SiGe middle layer. The first SiGe transition layer can have a Ge content increasing from a bottom of the first SiGe transition layer to a top of the first SiGe transition layer. The second SiGe transition layer can have a Ge content decreasing from a bottom of the second SiGe transition layer to a top of the second SiGe transition layer.申请人：Shanghai Huali Microelectronics Corporation地址：Shanghai CN国籍：CN更多信息请下载全文后查看。

抗氧化制剂普罗布考的临床研究现状_朱冰坡

·综述·抗氧化制剂普罗布考的临床研究现状朱冰坡　综述　范利　审校(解放军总医院老年心内科,北京　100853)[关键词]　抗氧化;　氧化型低密度脂蛋白;　动脉粥样硬化;　药物疗法[中图分类号]R972.6 [文献标识码]A [文章编号]1673-1913(2005)04-0252-03收稿日期:2004-06-22作者简介:朱冰坡,男,1978年8月生,河南省孟津市人,住院医师,硕士,从事老年心血管内科专业。

普罗布考(probuco l ),又名丙丁酚,化学名:4,4′-[(1-甲基亚乙基)双(硫)]双[2,6-双(1,1-二甲基乙基)苯酚],于1977年首先在美国上市,最初以降脂药应用于临床,主要降低血清胆固醇。

近几年发现其有抗氧化及抗动脉粥样硬化作用,能够从多个途径降低氧化低密度脂蛋白(o x -LDL )水平,预防或延缓动脉粥样硬化的发生和发展,减少心肌梗死及脑卒中的发病率,同时还可预防P T CA 术后的再狭窄。

本文对其研究现状作一综述。

1　普罗布考的药代动力学普罗布考经胃肠道吸收有限且不规则,如与食物同服可使其吸收达最大。

一次口服后18h 达血药浓度峰值,T 1/2为52～60h 。

每天服可使血药浓度逐渐增高,3～4个月达稳态水平。

动物实验表明,普罗布考主要积聚在脂肪组织,其在脂肪组织的浓度是血清中的100倍,肾上腺的25倍,肝脏的4倍,肌肉和心脏的2倍。

普罗布考可分布于胆汁和哺乳动物的乳汁,但尚不清楚是否分布于人乳中。

普罗布考在体内产生代谢产物。

口服剂量的84%从粪便排出,1%～2%从尿中排出,粪便中以原形为主,尿中以代谢产物为主。

2　血脂调节作用普罗布考对非家族性高胆固醇血症和家族性纯合子及杂合子型高胆固醇血症都有明显的降低作用。

短期用药(<3个月)降低血清总胆固醇(T C )10%～20%,降低低密度脂蛋白胆固醇(LDL -C )10%～20%。

长期用药(>3年)可降低血清T C 20%～25%。

布朗硼氢化反应英语

布朗硼氢化反应英语The Brown hydroboration reaction, discovered by Herbert C. Brown in the 1950s, revolutionized organic synthesis by offering a versatile method for selectively adding hydroxyl groups to alkenes. This reaction, which involves the addition of borane complexes to alkenes followed by oxidation, has found widespread applications in pharmaceuticals, materials science, and fine chemical manufacturing.The key to the Brown hydroboration reaction lies in its ability to provide anti-Markovnikov selectivity, where the hydroxyl group attaches to the less substituted carbon of the double bond. This selectivity contrasts with traditional acid-catalyzed hydration reactions, which typically follow Markovnikov's rule, favoring attachment to the more substituted carbon.The mechanism of the reaction proceeds in two mainstages. Initially, the alkene coordinates with the borane molecule to form a cyclic transition state, facilitating the addition of boron to the double bond. This step occurs rapidly and selectively due to the electron-deficient nature of borane. Subsequently, oxidation with hydrogen peroxide or other oxidants converts the borane complex into a hydroxyl group, yielding the final alcohol product.The Brown hydroboration reaction offers several advantages over alternative methods. Firstly, it provides a straightforward route to synthesizing alcohols with predictable regioselectivity, which is crucial in the pharmaceutical industry for controlling biological activity. Secondly, the reaction tolerates a wide range of functional groups, including esters, ketones, and nitriles, enhancing its utility in complex molecule synthesis. Additionally, the mild reaction conditions and high functional group tolerance make it compatible with sensitive substrates,reducing side reactions and improving yield.Applications of the Brown hydroboration reaction abound in drug discovery and development. It has been instrumental in the synthesis of pharmaceutical intermediates and natural product derivatives, where precise control over stereochemistry and regiochemistry is paramount. Furthermore, its versatility extends to the preparation of polymers and advanced materials, where tailored functional groups are essential for optimizing material properties.In conclusion, the Brown hydroboration reaction represents a cornerstone of modern organic chemistry, offering chemists a powerful tool for synthesizing complex molecules with high selectivity and efficiency. Its impact spans from fundamental research to industrial applications, driving innovation in fields as diverse as medicine, materials science, and beyond. As research continues to refine reaction conditionsand expand substrate scope, the Brown hydroboration reaction remains at the forefront of organic synthesis, poised to shape the future of chemical innovation.。

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Journal of Energy Chemistry25(2016)131–135/journal-of-energy-chemistry/Contents l i sts a v ai l a ble a t Sc i enceD i rectJournal of Energy Chemistryj ourn a l ho m ep a ge:www.elsev i er.co m/loc a te/j eche mBoron-doped Ketjenblack based high performances cathode for rechargeable Li–O2batteriesYueyan Li a,Li Wang b,Xiangming He b,∗,Bin Tang c,Yunxue Jin a,∗,Jianlong Wang ba Faculty of Materials Science and Engineering,Jiangsu University of Science and Technology,Zhenjiang212003,Jiangsu,Chinab Institute of Nuclear&New Energy Technology,Tsinghua University,Beijing100084,Chinac Jiangsu Huadong Institute of Li-ion battery,Zhangjiagang215600,Jiangsu,Chinaa r t i c l e i n f oArticle history:Received28April2015Revised23June2015Accepted23June2015Available online3September2015Keywords:Li–O2batteryRechargeableDischarge capacityBoron-doped KetjenblackOxygen reduction a b s t r a c tBoron-doped Ketjenblack is attempted as cathode catalyst for non-aqueous rechargeable Li–O2batteries.The boron-doped Ketjenblack delivers an extremely high discharge capacity of7193mAh/g at a current density of 0.1mA/cm2,and the capacity is about2.3times as that of the pristine KB.When the batteries are cycled with different restricted capacity,the boron-doped Ketjenblack based cathodes exhibits higher discharge platform and longer cycle life than Ketjenblack based cathodes.Additionally,the boron-doped Ketjenblack also shows a superior electrocatalytic activity for oxygen reduction in0.1mol/L KOH aqueous solution.The improvement in catalytic activity results from the defects and activation sites introduced by boron doping.©2015Science Press and Dalian Institute of Chemical Physics.All rights reserved.1.IntroductionNon-aqueous rechargeable Li–O2batteries are promising for en-ergy storage systems because of their excellent energy density[1,2]. However,the practical speciﬁc capacity is very limited when com-pared with the theoretical due to the high irreversibility and poor kinetics of the cathode reaction.Many factors,such as electrolyte, structures of carbonaceous materials and oxygen reduction catalysts, show great effect on the deliverable energy density of a Li–O2battery [3,4].The porous oxygen cathode plays an important role in the oxy-gen reduction reaction(ORR)during discharge process[5],however the ORR is too sluggish[6],that it usually requires metal oxides or noble metal catalysts to enhance the kinetics.The noble metal cat-alysts like Pt is conﬁrmed to be effective,however its widespread use is impeded due to its high cost and limited nature resource [7].Therefore,there is a great incentive toﬁnd cheap,stable and more effective metal-free ORR catalysts to retain a high discharge voltage.To date,various carbon materials have been prepared for air cath-odes,including Super P,Ketjen Black(KB),carbon nanotubes and graphene.However,their pristine forms are deﬁcient to satisfy spe-ciﬁc demands for lots of different applications[8–10].It has been∗Corresponding authors.Tel:+861062794226;Fax:+861089796031.E-mail addresses:hexm@(X.He),jinyunxue@(Y.Jin).proved that substitutional doping of heteroatoms in the graphitic lat-tice is an effective way to optimize the material properties[11,12]. Since B and N have small size mismatches,they are the most pop-ular heteroatoms when compared with the other doping elements (P,S,Si)[13].For instance,N-doped carbon materials have drawn much attention because conjugation between the nitrogen lone-pair electrons and grapheneπ-systems can signiﬁcantly enhance the ORR activity[14].More recently,Zhang and co-workers have success-fully prepared B-doped graphene(BG)by a thermal annealing ap-proach[15].The product BG has been demonstrated to show bet-ter ORR electrocatalytic activity than pristine graphene.Furthermore, Zhang and co-workers synthesized B/N co-doping graphene(BCN), which exhibited superior electrocatalytic activities to the commer-cial Pt/C electrocatalyst[16].The excellent electrochemical perfor-mance of BCN could be attributed to the defects and functional groups as active sites arising from the N and B co-doping doping. Taken together,the above doped materials have been widely used as metal-free catalysts for fuel cells and metal–air batteries.We no-ticed that there were only a few reports focusing on the perfor-mance improvement of B-doped carbon materials as cathode ma-terials for Li–O2batteries,such as the discharge platform and rate capability.Herein,for theﬁrst time,we successfully prepared B-doped KB (B-KB)and employed the material as cathode catalyst for Li–O2bat-tery.The result showed that the B-KB not only exhibited excellent electrocatalytic activity for ORR but also delivered an extremely high discharge capacity and stable discharge platform./10.1016/j.jechem.2015.08.0112095-4956/©2015Science Press and Dalian Institute of Chemical Physics.All rights reserved.132Y.Li et al./Journal of Energy Chemistry 25(2016)131–135V o l t a g e (V )Capacity (mAh/g)V o l t a g e (V )Capacity (mAh/g)Fig.1.(a)Initial discharge curves of the KB and B-KB cathodes between 2.3and 4.3V at various current densities,(b)full discharge/charge curves of B-KB between 2.0and 4.3V at 0.1mA/cm 2.2.Experimental 2.1.MaterialsInitially,commercial Ketjenblack (KB)EC600JD was washed with 6mol/L HCl solution for the removal of metal impurities.Then,the carbon materials were oxidized with 70wt%HNO 3for 6h and then rewashed and ﬁltered,followed by drying in an oven at 80°C.To prepare B-KB,the oxidized KB and boric acid (H 3BO 3)in a weight ratio of 1:5were mixed and ground in a mortar,and the mix-ture was then placed in the center and heated at 900°C for 4h.After being cooled down to room temperature in Ar atmosphere,the prod-ucts were reﬂuxed in deionized water at 85°C for 6h to extensively remove excessive boric oxides and were then ﬁltered and ﬁnally dried in vacuum.2.2.Physical characterizationsMorphologies of the KB and the B-KB were examined using scan-ning electron microscopy (SEM,JSM-6701F,JEOL,Japan).The X-ray diffraction (XRD)spectra were recorded using Rigaku D/MAX2400diffractometer (Japan,Cu K αradiation).The X-ray photoelectron spectroscopy (XPS,PHI-5702,Physical Electronics,USA)was used to conﬁrm the composition and the state of boron and carbon in the samples.The Fourier transform infrared spectroscopy (FTIR)spec-tra were collected on NicoletMAGNA-560,using KBr pellets.The de-fects,ordered and disordered structures were characterized by Ra-man spectroscopy (Jobin Yvon LabRam HR800,excited by 632.8nm He–Ne red laser).2.3.Electrochemical measurementsA catalyst paste was prepared by casting a slurry mixture of B-KB,KB and polytetraﬂuoroethylene (PTFE)in a ratio of 8:1:1,and the mixture was roller-pressed into a stainless steel parative electrodes made with KB and PTFE in a weight ratio of 9:1were also prepared in a similar way.Swagelok type cells were employed for charge/discharge tests.The electrolyte was 1mol/L LiTFSI (99.995%pure)in TEGDME (Triethylene glycol dimethyl ether,Aldrich).The cells were cycled using LAND-CT2001A testers in a voltage range of 2.3–4.3V at different current densities.All the electrochemical mea-surements were carried out in a dry and pure oxygen atmosphere at 25°C.3.Results and discussionThe discharge and charge measurements of KB and B-KB elec-trodes were performed in the voltage range of 2.3–4.3V.As shown in Fig.1(a),the initial discharge capacity and average operating volt-age at the current density of 0.1mA/cm 2were 7193mAh/g and 2.8V for B-KB cathode,while 3202mAh/g and 2.6V for the pris-tine KB.With the current density increasing,the achieved capaci-ties dropped signiﬁcantly.The discharge capacities of both samples decreased to 2752and 1979mAh/g for B-KB and KB at the cur-rent density of 0.2mA/cm 2,respectively.B-KB electrodes not only delivered higher discharge capacity but also exhibited higher av-erage discharge plateau than KB electrodes at different discharge current densities,demonstrating a superior ORR activity.Fig.1(b)shows the cycling performance of Li–O 2battery at a current density of 0.1mA/cm 2using B-KB as the cathode supporting material.The cathode delivered an initial discharge capacity of 7193mAh/g,and then the capacity rapidly decayed to 1894mAh/g within three cycles.The electrode exhibited unsatisfactory cycleability under this condi-tion,which could be attributed to the accumulation of the discharge products and instability of the electrolyte in the deep discharge process.In order to avoid the over-growth of discharging products,the bat-teries were tested with a limited capacity at the current density of 0.1mA/cm 2.The KB cathodes were tested for comparison,and it showed only 9cycles with a cycling capacity of 600mAh/g (Fig.2a).The discharge platform and cutoff voltage of the cell at the discharge state obviously dropped in every cycle,as shown in Fig.2(b).When cycled with different limited capacities (600mAh/g,1000mAh/g and 2000mAh/g)at a current density of 0.1mA/cm 2,as shown in Fig.3,the cells exhibited more excellent cycle ability than those of KB cath-odes.In detail,the reversible capacity kept well for 23cycles with 600mAh/g capacity limitation,14cycles with 1000mAh/g capacity limitation and 7cycles with 2000mAh/g capacity limitation.More-over,B-KB cathodes also showed higher average operating voltage and lower overpotential than KB.The discharge platform and cut-off voltage of the B-KB cathode based cells at the discharge state showed a similar trend to those of KB,although the voltage still de-creased,the decreasing rate was slower.This phenomenon also sug-gested that by limiting the depth of discharge,the cycle ability of the Li–O 2battery could be improved.The main reason is that the increas-ing rate of the electrode resistance is slower by restricting discharge capacity,and which means the charge process could overcome the partially chocked air cathode and the decomposition of Li 2O 2and Li 2O recovers the porosity and makes the subsequent cycle possible [3].To further conﬁrm the superior catalytic activity of B-KB to KB,ORR in aqueous solution is investigated.Cyclic voltammograms of the electrochemical reduction of O 2at KB/GCE and B-KB/GCE in O 2saturated 0.1mol/L KOH aqueous solution were collected in a three-electrode system (GCE or modiﬁed GCE as the working electrode,a Pt wire as counter electrode,and an Ag/AgCl as the reference).AsY.Li et al./Journal of Energy Chemistry 25(2016)131–135133V o l t a g e (V )Capacity (mAh/g)V o l t a g e (V )Cyclenumber, nFig.2.(a)The limited depth of discharge/charge at 600mAh/g at 0.1mA/cm 2of the KB cathode,(b)the variation of cutoff voltage with cycles when the discharge capacity is limited to 600mAh/g.V o l t a g e (V )Capacity (mAh/g)V o l t a g e (V )Cyclenumber, nV o l t a g e (V )Cyclenumber, nV o l t a g e (V )Capacity (mAh/g)V o l t a g e (V )Capacity (mAh/g)V o l t a g e (V )Cyclenumber. nFig.3.The limited depth of discharge/charge and the cutoff voltage with the limited discharge capacity at 0.1mA/cm 2of the B-KB cathodes:(a,b)the cases when the discharge capacity is limited to 600mAh/g;(c,d)the cases when the discharge capacity is limited to 1000mAh/g;(e,f)the cases when the discharge capacity is limited to 2000mAh/g.134Y.Li et al./Journal of Energy Chemistry 25(2016)131–1352θ(o )C u r r e n t d n e s i t y (m A /c m 2)Potensive (Vvs.Ag/AgCl)Fig.4.(a)The cyclic voltammograms of KB and B-KB electrodes in O 2-saturated 0.1mol/L KOH solution at a scan rate of 10mV/s,(b)XRD patterns of KB and B-KB.Fig.5.(a)SEM image of KB,(b)SEM image of B-KB.shown in Fig.4(a),the onset potential of ORR on the B-KB/GCE oc-curred at –0.19V vs.Ag/AgCl,which was about 50mV higher than on KB/GCE.The higher electrocatalytic activity of B-KB/GCE indicates faster electron transfer kinetics for ORR.Even compared with other B-doped carbon materials in previous reports,the B-KB exhibited better electrocatalytic activity.For instance,Zhang and co-workers reported that B-doped graphene showed an ORR peak located at -0.34V [17].The excellent ORR performance of B-KB could be due to the B-doping.When boron is bonded with a carbon lattice,it introduces a shift in Fermi level to the conducting band and a defect in the nearby sites [18],which may not only increase the electronic conductivity but also beneﬁt in stabilizing active intermediates,and consequently enhance the electrocatalytic activity.Fig.4(b)provides the XRD patterns of KB and B-KB.The XRD spec-tra of these carbons reﬂect a weak diffraction peak around 43°corre-sponding to the (100)plane of graphite.However,the XRD pattern of B-KB shows a broad and strong peak indexed to (002)around 24.6°,while KB’s locates at 2θ=23.9°,and the observable shift could be attributed to the incorporation of boron into the carbon layers.Fig.5shows the high magniﬁcation SEM images of KB and B-KB.The mi-crostructures of both KB and B-KB revealed the presence of highly dense ﬁbrous and displayed no obvious difference.The Raman spectra of B-KB and KB are shown in Fig.6(a).The peaks around 1336cm −1and 1585cm −1are corresponding to the D and G bands,respectively.The G band is attributed to the bond stretching of all sp 2carbon domains,while the D band is related to the sp 3defect sites and disordered carbon [18].Generally,the inten-sity ratio of D and G bands (I D /I G )provides the indication of the disor-der degree of carbon materials.No signiﬁcant shift in the position of D and G bands is observed,but the I D /I G values increase from 1.15forTable 1.Atomic percentage of KB and B-KB.(%)B-KB KB C 95.2299.11O 3.480.89B1.3KB to 1.21for B-KB,conﬁrming that the B-KB possesses many more defects than the KB after the boron-doping.XPS analysis was carried out to reveal the elemental composition and boron bonding conﬁgurations in B-KB.As shown in Fig.6(c),the survey scan of the B-KB sample showed B 1s peak centered at 191.2eV besides the existence of C 1s and O 1s peaks.Three peaks can be iden-tiﬁed (Fig.6d)according to the curve ﬁtting.A distinct peak is found at a binding energy of 191.7eV,characteristic of BC 3.Two shoulders centered at 190.8eV and 192.7eV may be assigned to the structure of boron atoms bonding to carbon and oxygen atoms (BC 2O)and B–O bonds,respectively [19].In addition,The C–B and B–O chemical bonds were observed in the corresponding FTIR spectrum shown in Fig.6(b).All these results illustrate B atoms have been successfully incorporated into the carbon lattice.Table 1displays the atomic percentages of KB and B-KB.It is in-teresting to see that the percentage of oxygen is lower in the pris-tine KB than in the B-KB.The increased oxygen may be due to the low-concentration boron doping,which generates catalytic effect on oxygen chemisorptions.Moreover,the redistribution of πelec-trons in the doped boron weakens C–C bonding and strengthens C–O bonding [20].Hence,the B-KB materials possess higher oxygen concentrations.Y.Li et al./Journal of Energy Chemistry 25(2016)131–135135I n t e n s i t y (a .u .)-1I n t e n s i t y (a .u .)-1I n t e n s i t y (a .u .)Bindingenergy (eV)I n t e n s i t y (a .u .)Bindingenergy (eV)Fig.6.(a)Raman spectra of B-KB and KB,(b)FTIR spectrum of B-KB,(c)XPS survey spectra of KB and B-KB,(d)high resolution B 1s XPS spectrum.4.ConclusionsThe boron-doped Ketjenblack (B-KB)electrode can deliver a larger discharge capacity and higher discharge platform than undoped KB,which is attributed to the defects and activation sites introduced by boron doping.To avoid the over-growth of discharged products in-duced by deep discharge,the battery is cycled at a restricted depth of discharge.Then the cell with B-KB cathodes exhibits good capacity retention.This result provides a reasonable approach to cathode of high performance for Li–O 2batteries.AcknowledgmentsThis work is supported by the MOST (Grant nos.2013CB934000and 2014DFG71590),Beijing Municipal Program (Grant no.YETP0157).References[1]K.Abraham,Z.Jiang,J.Electrochem.Soc.143(1996)1.[2]M.Armand,J.M.Tarascon,Nature 451(2008)652.[3] 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