Biostratigraphic Study of the Paleocene-Eocene Boundary in Northern Tunisia, North Africa
遗传学习题含答案
《遗传学》习题第一章绪论一、名词解释：1、遗传与变异2、遗传变异3、遗传学二、填空题：1、1883年，德国动物学家魏斯曼（A.Weismann）提出。
2、孟德尔通过豌豆杂交实验，提出了遗传因子的分离定律和自由组合定律，但当时并未引起重视，直到年，由三个植物学家在不同的地点，不同的植物上，得出与孟德尔相同的遗传规律，这时遗传学才作为一门独立的学科诞生。
3、1903年和首先发现了染色体的行为与遗传因子的行为很相似，提出了染色体是遗传物质的载体的假设。
4、遗传学诞生后，遗传学名词是1906年由英国的教授提出来的。
5、1909年，丹麦遗传学家创造了一词来代替孟德尔的遗传因子，并且还提出了和概念。
6、1910年，和他的学生用果蝇做材料，研究性状的遗传方式，得出，确定基因直线排列在染色体上，创立了以遗传的染色体学说为核心的。
7、1940年以后，以红色面包霉为材料，系统地研究了生化合成与基因的关系，于1941年提出一个基因一个酶的假说。
8、1944年，等用肺炎双球菌做转化实验，证明DNA是遗传物质。
9、1951 发现跳跃基因或称转座因子。
10、1961年，法国分子遗传学家以E.coli为材料，研究乳糖代谢的调节机制，提出了。
11、分子遗传学时期以1953年美国分子生物学家和英国分子生物学家提出的为开始。
三、选择题：1、遗传学有很多分支，按（），可分为宏观与微观，前者包括群体遗传学(Population genetics)、数量遗传学(Quantitative gentics)；后者包括细胞遗传学(Cytogenetics)、核外遗传学(Extranuclear G.)、染色体遗传学(Chromosomal G.)、分子遗传学(Molecular genetics)。
A、按研究对象分B、按研究范畴分C、研究的层次分D、研究的门类2、遗传学名词是1906年由英国的贝特森William Bateson教授提出来的，并且他还提出了（）等概念。
大黄素治疗类风湿关节炎
大黄素治疗类风湿关节炎发布时间：2023-02-22T08:45:15.571Z 来源：《医师在线》2022年32期作者：郑若男[导读] 类风湿性关节炎（RA）是一种慢性、全身性和自身免疫性疾病，其主要病理变化是炎症细胞浸润伴有多种相关细胞因子的分泌和积累，诱发软骨和骨组织的破坏。
因此，炎症细胞和细胞因子的调节是控制RA炎症的关键治疗靶点。
本综述详细介绍了大黄素对T淋巴细胞、树突状细胞和调节性T细胞分化和成熟的影响。
郑若男黑龙江中医药大学黑龙江哈尔滨 150000摘要：类风湿性关节炎（RA）是一种慢性、全身性和自身免疫性疾病，其主要病理变化是炎症细胞浸润伴有多种相关细胞因子的分泌和积累，诱发软骨和骨组织的破坏。
因此，炎症细胞和细胞因子的调节是控制RA炎症的关键治疗靶点。
本综述详细介绍了大黄素对T淋巴细胞、树突状细胞和调节性T细胞分化和成熟的影响。
此外，系统引入大黄素直接或间接影响促炎细胞因子（TNF-α、IL-6、IL-1、IL-1β、IL-17、IL-19和M-CSF）和抗炎细胞因子（IL-4、IL-10、IL-13和TGF-β的分泌），通过多种炎性细胞因子的共调节来抑制RA炎症并促进恢复。
详细了解大黄素治疗RA的潜在机制，为大黄素今后的临床应用提供了系统的理论依据。
关键词：大黄素；类风湿关节炎；综述1 大黄素的基础生物学中药大黄和根瘤被称为“指挥官”，最早记录在经典书籍“神农草药经典”中，大约在2000年前在中国临床上使用。
本代表中药泻药可用于净化治疗凝冷、清热火、化血化瘀、降血消黄、清热、利尿[1-2].大黄素是一类最近备受关注的生物活性天然产物。
大黄素具有多种生物调节功能，如免疫抑制和抗肿瘤、抗氧化和抗炎活性.因此，大黄素在心血管系统、呼吸系统、代谢系统、神经系统和其他系统的疾病中具有治疗潜力。
1.1 大黄素的药代动力学大黄素的主要代谢途径是葡萄糖醛酸化代谢，其次是磺化代谢[3].大黄素以葡糖苷酸或硫酸酯的形式存在于血浆、肾脏和肺中，以游离形式存在于肝脏中的大黄素[4].1.2使用大黄素治疗人类疾病在口腔疾病中，大黄素降低外周血和牙龈组织中的一氧化氮（NO）水平，抑制炎症反应和牙槽骨吸收[5].在肝病中，大黄素可以通过下调丙氨酸氨基转移酶（ALT）、甘油三酯和天冬氨酸氨基转移酶的水平来改善乙醇介导的肝脂肪变性并治疗酒精性肝病[6].关于氧化应激损伤，大黄素发挥潜在的抗氧化作用，例如调节自由基和活性氧（ROS）水平并影响氧化应激诱导的损伤[7].在心血管疾病中，大黄素通过抑制醛糖还原酶活性和改善视网膜血管生成对糖尿病视网膜病变发挥潜在的治疗作用[8].1.3免疫细胞中大黄素的调节大黄素的免疫调节功能主要影响T淋巴细胞、树突状细胞（DC）和调节性T细胞（Tregs）的分化和成熟以及多种促炎和抗炎细胞因子的分泌，以达到免疫调节作用[9].2 大黄素通过调节炎性细胞因子影响 RA 进程大黄素的免疫调节作用可能部分归因于其对淋巴细胞的抗增殖作用及其对 TH1/TH2 和 TH17/Treg 平衡的调节 [10].为了抑制炎症，大黄素降低血浆中TNF-ɑ和IL-6的水平，并抑制PGE（2）的产生，PGE（2）是COX-2在滑膜组织中的蛋白质表达[11]以及抗炎细胞因子IL-4，IL-10，IL-13，IL-11和TGF-β在细胞内外的协同作用。
2008PNAS青藏高原抬升
Constraints on the early uplift history of the Tibetan PlateauChengshan Wang*†,Xixi Zhao†‡,Zhifei Liu§,Peter C.Lippert‡,Stephan A.Graham¶,Robert S.Coe‡,Haisheng Yiʈ, Lidong Zhuʈ,Shun Liuʈ,and Yalin Li**State Key Laboratory of Geological Processes and Mineral Resources,Research Center for Tibetan Plateau Geology,and School of Geosciences,China University of Geosciences,Beijing100083,People’s Republic of China;‡Department of Earth and Planetary Sciences and Institute of Geophysics and Planetary Physics,University of California,Santa Cruz,CA95064;§Laboratory of Marine Geology,Tongji University,Shanghai200092,People’s Republic of China;¶Department of Geological and Environmental Sciences,Stanford University,Stanford,CA94305;andʈSchool of Geosciences, Chengdu University of Technology,Chengdu610059,People’s Republic of ChinaEdited by W.G.Ernst,Stanford University,Stanford,CA,and approved January25,2008(received for review June14,2007)The surface uplift history of the Tibetan Plateau and Himalaya is among the most interesting topics in geosciences because of its effect on regional and global climate during Cenozoic time,its influence on monsoon intensity,and its reflection of the dynamics of continental plateaus.Models of plateau growth vary in time, from pre-India-Asia collision(e.g.,Ϸ100Ma ago)to gradual uplift after the India-Asia collision(e.g.,Ϸ55Ma ago)and to more recent abrupt uplift(<7Ma ago),and vary in space,from northward stepwise growth of topography to simultaneous surface uplift across the plateau.Here,we improve that understanding by presenting geologic and geophysical data from north-central Tibet, including magnetostratigraphy,sedimentology,paleocurrent mea-surements,and40Ar/39Ar andfission-track studies,to show that the central plateau was elevated by40Ma ago.Regions south and north of the central plateau gained elevation significantly later. During Eocene time,the northern boundary of the protoplateau was in the region of the Tanggula Shan.Elevation gain started in pre-Eocene time in the Lhasa and Qiangtang terranes and ex-panded throughout the Neogene toward its present southern and northern margins in the Himalaya and Qilian Shan.climate͉tectonics͉magnetostratigraphy͉Hoh Xil Basin͉CenozoicT he Tibetan Plateau is the most extensive region of elevated topography in the world(Fig.1).How such high topography, which should have an effect on climate,monsoon intensity,and ocean chemistry(1–5),has developed through geologic time re-mains disputed.Various lines of investigation,including evidence from the initiation of rift basins(6),potassium-rich(K-rich)vol-canism(7),tectonogeomorphic studies of fluvial systems and drainage basins(8),thermochronologic studies(9),upper-crustal deformation histories(10,11),stratigraphic and magnetostrati-graphic studies of sediment accumulation rates(12),paleobotany (13),and oxygen isotope-based paleoaltimetry(14–22),have sug-gested different uplift histories.Authors of recent geologic studies (11)have proposed that significant crustal thickening(and by inference,surface uplift)in the Qiangtang terrane occurred in the Early Cretaceous[Ϸ145mega-annum(Ma)age],followed by major crustal thickening within the Lhasa terrane betweenϷ100and50 Ma ago.This hypothesis remains disputed(23).Other models of plateau growth range from Oligocene(e.g.,Ϸ30Ma ago)gradual surface uplift(7)to more recent(Ͻ7Ma ago)and abrupt surface uplift(24),with oblique stepwise growth of elevation northward and eastward after the India-Eurasia collision(7,20,25,26).With few exceptions(e.g.,see refs.11and27),most of these models focus on data from the Himalaya and southern Tibet and remain rela-tively unconstrained by geologic data from the interior of the Tibetan Plateau.The Hoh Xil Basin(HXB)of the north-central Tibetan Plateau (Figs.1and2)is the most widespread exposure of Paleogene sediments on the high plateau and containsϾ5,000m of Cenozoic nonmarine strata(28).Although the HXB(5,000-m average ele-vation)is a part of the high plateau today,it once was a basin bounding the northern boundary of the Paleogene proto-Tibetan Plateau.The HXB,characterized by low-gradient fluvial and lacustrine facies,may be an analogue of the Qaidam or Tarim basin systems on the northern margins of the modern high plateau,which are a variety of foreland basins termed‘‘collisional successor basins’’by Graham et al.(29).Here,we argue that the HXB is a foreland basin system that developed in concert with the rise and erosion of adjacent high mountain belts.Specifically,our work supports the idea that HXB evolution was coeval with the surface uplift of the Qiangtang terrane to the south and that high elevation characterized the central Tibetan Plateau by Eocene time. Sedimentology and Magnetostratigraphy of the HXBHXB sediments are exposed most extensively in the Fenghuo Shan (‘‘shan’’means‘‘mountain’’in Chinese)region and can be divided into three lithostratigraphic units.The basal Fenghuoshan Group (FG)consists of cobble-pebble conglomerate,red sandstone,and bioclastic limestone of fluvial,fan-delta,and lacustrine origin.The overlying Yaxicuo Group(YG)is distinguished by sandstone, mudstone,marl,and gypsum deposited in fluvial and playa envi-ronments.A pronounced angular unconformity separates the YG from the overlying Wudaoliang Group(WG),which consists of lacustrine marl and minor amounts of black oil shale.The FG and YG together areϾ5,000m thick and deformed by overturned folds and numerous south-directed thrusts,whereas the100-to200-m-thick WG is only gently tilted.Nearly300paleocurrent measurements indicate that the paleo-flow direction recorded in the FG is dominantly northward(Fig.2), consistent with provenance studies and proximal-to-distal facies distributions that show that detritus in the HXB was derived from the Qiangtang terrane to the south(30)and controlled by the Tanggula thrust system[for data,see supporting information(SI) Figs.7and8in SI Appendix].Paleocurrent indicators in the YG are also directed to the north in its lower part but are increasingly deflected eastward higher in the section,with some southerly indicators at the top of the section(Fig.2).Thus,paleoflow indictors are mainly directed northward away from the Tanggula Shan front and eastward parallel to the front.Chinese workers traditionally have regarded the initiation of the HXB as Cretaceous on the basis of pollen biostratigraphy Author contributions:C.W.designed research;C.W.,X.Z.,Z.L.,H.Y.,L.Z.,S.L.,and Y.L. performed research;C.W.,X.Z.,Z.L.,P.C.L.,S.A.G.,R.S.C.,H.Y.,L.Z.,and S.L.analyzed data; and C.W.,X.Z.,P.C.L.,S.A.G.,and R.S.C.wrote the paper.The authors declare no conflict of interest.This article is a PNAS Direct Submission.Freely available online through the PNAS open access option.†To whom correspondence may be addressed.E-mail:chshwang@ or xzhao@ .This article contains supporting information online at /cgi/content/full/ 0703595105/DC1.©2008by The National Academy of Sciences of the USA͞cgi͞doi͞10.1073͞pnas.0703595105PNAS͉April1,2008͉vol.105͉no.13͉4987–4992G E O L O GY(31).Our magnetostratigraphic studies from several HXB sections,however,suggest that these strata are much younger (32).The FG was deposited Ϸ52.0–31.3Ma ago (Early Eocene to Early Oligocene),and the YG was deposited 31.3–23.8Ma ago (Early Oligocene)(Fig.2).The base of the WG is biostratigraphically dated at Ϸ22Ma ago (Miocene)(31).Average magnetostratigraphically derived sedimentation rates for the FG and YG exceed 200m/Ma and,in detail,indicate at least three general periods of sediment accumulation (32).From Ϸ55to 40Ma ago,sedimentation rates averaged Ϸ150m/Ma,increased significantly to 1,500m/Ma at Ϸ40Ma ago,and decreased to Ϸ400m/Ma from Ϸ39to 30Ma ago.The rapid acceleration in sedimentation rates at Ϸ40Ma ago coincides with the deposition of a coarsening-upward boulder-cobble conglomerate.We interpret these conglomerates as syntectonic and,therefore,that they may record activity on basin-bounding thrusts such as the Tanggula thrust system (Fig.3).Fig.2.Lithologic and magnetochronostratigraphic correlations of measured sections in the Tongtianhe,Fenghuoshan,and Wulanwula subbasins of the HXB.Magnetochronostratigraphy of the Fenghuoshan subbasin is from ref.32.Paleocurrent directions indicate westerly and southerly provenances in the Eocene and most of the Oligocene and northerly provenance in the latest Oligocene.The star in the Fenghuoshan section indicates the carbonate sampling site discussed in ref.18.Fig.1.A simplified tectonic map of the Tibetan Plateau and Himalaya that shows the major tectonic blocks,suture zones,large faults,and basins dis-cussed in the text.JB,Jiuquan basin;QB,Qaidam basin;GBC,Gangrinboche conglomerates;GCT,great counter thrust;GT,Gangdese thrust;NKLF,north Kunlun fault;SKLF,south Kunlun fault;ATF,Altyn Tagh fault;XF,Xianshui River fault;TTS,Tang-gula thrust system;JF,Jingsha fault;BNS,Bangong–Nujiang suture zone;YZS,Yarlung Tsangpo suture zone;MBT,main boundary thrust.Small circles with numbers represent sites for Ar/Ar dating:1–3,sites studied in ref.7;4,sites at which samples of K-rich lavas in the Zhuerkenwula mountain area (west of longitude 91°30ЈE;see Figs.3and 4a and c )were collected for Ar/Ar dating;5,HXB volcanic sites (see Fig.4b and c ).Labeled boxes (with letters)represent areas at which previous studies for paleoelevation,sedimentology,and magnetostratigraphy of Ceno-zoic sections were conducted:L,Lunpola (20);FS,Fenghuo Shan (18);N (13,17);J (43);P (44);Z (see SI Fig.12in SI Appendix ).WS,FS,and TS represent theWulanwula,Fenghuoshan,and Tongtianhe sections,respectively,shown in Fig.2.The large box in the center shows the location of the map shown in Fig.3.4988͉ ͞cgi ͞doi ͞10.1073͞pnas.0703595105Wang et al.Crustal Shortening and Fission-Track Analyses of North-Central TibetAs previously discussed,field relationships (Fig.3)indicate that FG and YG strata were strongly deformed before deposition of the WG (30).Structural cross sections suggest that crustal shortening in the Fenghuo Shan region is Ϸ43%(30,33),with the majority of this shortening complete by the end of the Oligocene.These structural relationships are similar to those observed in the Nanqian-Yushu region to the east (27,34).Our results from an apatite fission-track study of 25samples from the Tanggula Shan and HXB provide constraints on the regional cooling history (SI Figs.9and 10in SI Appendix ).Early Paleogene apatite fission-track ages and negatively skewed track-length dis-tributions of basement rock samples from the Tanggula Shan indicate a rapid cooling event Ϸ60–50Ma ago followed by more gradual cooling thereafter.This cooling history can be explained by either regional Early Cenozoic volcanism (34,35),tectonic exhu-mation,or a combination of these processes.Overlap in U/Pb ages in zircon,40Ar/39Ar ages in biotites (34,35),and apatite fission-track ages of volcanic and sedimentary samples is consistent with rapid unroofing of the northern Tanggula Shan by motion along the Tanggula thrust system.Moreover,extensive Late Paleogene flat-lying basalts (see below)that overlie strongly deformed Early Paleogene strata indicate that significant upper-crustal deforma-tion and denudation on the northern flank of the Tanggula Shanwas mostly compete by Ϸ40Ma ago.In the HXB,apatite fission-track samples from 40-to 35-Ma-old FG strata exhibit shorter mean track lengths and track-length distributions suggestive of cooling beginning Ϸ30Ma ago.These results are compatible with the sedimentary accumulation records for the HXB,indicating as much as 3,500m of sediment overburden,and the structural history described above,indicating rapid exhumation of the Fenghuo Shan Ϸ30–22Ma ago.Paleogene High-Potassium Volcanism in North-Central Tibet Many workers attribute the surface uplift of the Tibetan Plateau to a dynamic response to convective removal of the lower portion of an overthickened Tibetan lithosphere (36).Hot asthenosphere beneath a thin lithosphere is expected to produce not only dynamic topography but also crustal melts (37).Thus,the occurrence of K-rich,postcollisional volcanism in elevated terranes may be useful for dating the time of surface uplift.Approximately one decade ago,it was widely believed that all postcollisional volcanic rocks in Tibet were younger than Ϸ13Ma and restricted to the northern and southern margins of the plateau (38).Recent results of others and those presented here,however,demonstrate that postcollisional volcanic rocks are widely distributed within the plateau interior and are older than those in the north and south (39,40).In particular,30-to 40-Ma-old K-rich lavas found across the eastern part of northern Tibet have been cited as evidence for diachronoussurfaceFig.3.Simplified geologic map of the Hoh Xil region (boxed area in Fig.1)based on 1:250,000-scale regional geologic mapping,showing the distribution of tectonically disrupted strata of the HXB and structural features.Note that the Jinsha River suture zone (JS,dashed red line)that separates Qiangtang and Songpan-Ganzi terrane is covered in this region.The dashed black line indicates the Qinghai-Tibet highway.TTS,Tanggula thrust system;SKLF,south Kunlun fault;A–B,location of the cross section on the lower left of the figure,which shows significant upper-crustal shortening in the Hoh Xil region.Paleogene volcanic fields of the Zhuerkenwula area are located in the western part of the region shown.Wang et al .PNAS ͉April 1,2008͉vol.105͉no.13͉4989G E O L O GYuplift and high elevations because previously reported K-rich volcanics from western Qiangtang are Ϸ20Ma old or younger (Fig.1)(7).Our 40Ar/39Ar geochronologic study of a recently discovered volcanic province in the Zhuerkenwula mountain area (Figs.3and 4a )reveals that K-rich volcanism began in western Qiangtang at least 33.7–43.5Ma ago.Calc-alkaline volcanic rocks of Eocene-Oligocene age were also documented recently in southern Qiang-tang (40).In the HXB,however,most K-rich lava units are even younger (6–24Ma;Fig.4b and c )and overlie redbeds of the foreland basin.Thus,east–west diachronous uplift of the Tibetan Plateau is not supported by the ages of K-rich lavas,which actually young northward from the Qiangtang terrane to the Kunlun Shan (Fig.4c ).Whether these melts are the product of lithospheric thinning or intracontinental subduction (35,41)remains a topic of active research.DiscussionWhen did regional surface uplift commence?The transition from marine to terrestrial facies is one of the most direct lines of evidence for uplift.The youngest marine strata of the Qiangtang terrane are Lower Cretaceous,whereas those of the Lhasa terrane are LateCretaceous (Fig.5).These folded deposits are unconformably overlain by Upper Cretaceous and Paleogene nonmarine deposits,as imaged by recent seismic profiling in the region (SI Fig.11in SI Appendix )and mapped in outcrop (11,42).This structural–stratigraphic relationship indicates that crustal shortening,thick-ening,and surface uplift were active in both the Qiangtang and Lhasa terranes well before the Early Eocene (10).South of the Lhasa terrane,recent biostratigraphic studies in the Himalayan terrane confirm the record of Paleocene marine deposition in both the northern and southern Tethyan Himalaya (43,44).Importantly,our work demonstrates that the marine Penqu Formation near Tingri is latest Eocene in age (Priabonian,calcareous nannofossil zone NP20),extending the age of marine incursion in the southern Tethyan Himalaya by Ϸ5Ma (44).We also have directly dated an Early Eocene (zone of Buryella clinata –Thursocyrtis ampla )radio-larian chert in Saga County in the northern Tethyan Himalaya (SI Fig.12in SI Appendix ),where previous studies have only inferred a mid-Paleogene age on the basis of Paleocene biostratigraphy and stratigraphic relationships (43,45).Thus,by using the disappear-ance of marine facies as a measure of early surface uplift,we conclude that the emergence of the Himalaya occurred post-Eocene at the earliest,possibly even more recently.Oxygen isotope-based paleoaltimetry studies from the Thakkhola graben and Gyirong basin suggest that the Tethyan Himalaya were at or near modern elevation by the mid-Miocene (14,15).Collectively,these studies are consistent with the sedimentary record of Himalayan orogenesis (46)and indicate significant southward elevation gain between 40and Ϸ12Ma ago.When the proto-Tibetan Plateau (the Lhasa and Qiangtang terranes)reached its modern elevation remains uncertain (26),although regional paleoaltimetry studies provide some constraints.Independent paleoaltimetry estimates from the Namling-Oiyung basin in southern Tibet (13,17)suggest that the elevation of the southern Tibetan Plateau has remained at Ϸ4.6km since 15Ma ago.Farther north,chronologically well constrained stable-isotope studies from the Nima basin along the Bangong–Nujiang suture between the Lhasa and Qiangtang terranes suggest that this region was high and dry,similar to the modern environment,by the Early Oligocene (22).Oxygen isotope studies of Paleogene strata in the Lunpola basin,which also spans the Bangong–Nujiang suture,suggest that the region was 4.0–4.6km high (20)by the Early Oligocene (22).Paleoaltimetry estimates from the Hoh Xil region are equivocal.Cyr et al .(18)used oxygen isotope values from lacustrine carbonates from the FG and modeled monsoon-dominated isotopic lapse rates to argue that the HXB was Ϸ2km high during the Late Eocene,whereas DeCelles et al .(22)reeval-uated these data by using lower,empirically based lapse rates from central Tibet and argue that the HXB was 4.7–5.0km high during the Late Eocene.Our evidence from stratigraphy,geochronology of K-rich lavas,and apatite fission-track studies,as well as the paleoaltimetry studies discussed above,support the idea that the Lhasa and southern Qiangtang terranes were at or near their modern elevation since 40Ma and formed the proto-Tibetan Plateau (Fig.6).The northern edge of the Tanggula Shan formed the northern margin of the proto-Tibetan Plateau,whereas the Gangdese arc formed the southern boundary,consistent with the inferences of Kapp et al .(11,47)and Spurlin et al .(34).Oligocene–Early Miocene upper-crustal shortening within the HXB would have been driven by Indo-Asian collisional stresses from the south transmitted across this high proto-Tibetan Plateau and localized along its northern boundary.Thus,we argue that the Tibetan Plateau grew southward and northward from a nucleus of high topography (Fig.6),consistent with predictions based on simple physical considerations (48,49).Surface uplift to 5,000m in the HXB region was probably achieved by a combination of upper-crustal shortening (50),continental underthrusting of the Lhasa and Songpan-Ganzi terranes beneath Qiangtang (11),and mantle dynamics(36).Fig.4.40Ar/39Ar plateau ages from this study.(a )Zhuerkenwula mountains,which is the largest Cenozoic volcanic province in the northern Tibetan-Kunlun region (Ϸ2,500km 2).The K-rich lavas in this province were previously considered to be Ͻ20Ma old.(b )Plateau ages from the Hoh Xil region.(c )Distributions of radiometric dates of K-rich lavas from the Qiangtang,Hoh Xil,and Kunlun belts (Ͼ200dates collected,mainly from refs.39and 60).4990͉ ͞cgi ͞doi ͞10.1073͞pnas.0703595105Wang et al.Concluding RemarksWe propose a temporally and spatially differential surface-uplift history of the Tibetan Plateau (Fig.6).Our integrated study suggests that the central plateau (the Lhasa and southern Qiang-tang terranes)was uplifted by the Late Paleogene.A high proto-Tibetan Plateau may have contributed to climatic changes farther north in central Asia (19).Intriguingly,this timing also corresponds to a period of pronounced global cooling (1,2)and changes in ocean chemistry (51).The plateau subsequently expanded as a result of the continued northward collision of India with Asia.To the south,the Himalaya rose during the Neogene.To the north,the Qilian Shan rapidly uplifted in the Late Cenozoic.These ranges constitute the modern southern and northern margins,respectively,of the Tibetan Plateau.Methods and Analytical TechniquesMagnetostratigraphy.Magnetostratigraphic sampling was conducted approxi-mately every 10m.Several sites include multiple samples at the same stratigraphic level.Sampling followed standard paleomagnetic practice with in situ drilling by a portable gasoline-powered core drill and sample orientation by sun compass.All experimental work was performed in a magnetically shielded laboratory at the University of California (Santa Cruz).Samples were subjected to progressivethermal and alternating field demagnetization and measured at each step of treatment by a 2G cryogenic magnetometer.Magnetization directions were determined by principal-component analysis (52).The distributions of paleomag-netic directions at each site were calculated by using Fisher statistics (53).Each of the major magnetic polarity zones were defined by several samples of the same polarity.Age constraints and spacing of the observed polarity intervals were used to anchor the observed polarity column to the geomagnetic time scale (54).Geochronology.40Ar/39Ar analyses were conducted on plagioclase mineral sep-arates from 10samples from the western regions of the northern Tibetan Plateau.The analytical procedures followed those described in ref.55.After irradiation,all samples were step-heated by using a radio-frequency furnace.Argon isotope analyses were conducted on a MM1200mass spectrometer at the Institute of Geology (China Seismological Bureau).40Ar/39Ar plateau ages are interpreted as eruption ages for the volcanic samples;all of the plateau ages are well defined over 75%of the cumulative 39Ar released and are statistically indistinguishable from their corresponding inverse isochron ages.Apatite Fission-Track Analyses.Samples for fission-track study came from a transect that followed the Lhasa-Golmud highway.All samples were measured at the University of Melbourne (Melbourne,Australia).Standard and induced track densities were measured on mica external detectors (g ϭ0.5).Ages were calcu-lated by using the zeta method (362.3Ϯ8)for dosimeter glass CN-5.EmpiricalFig.5.Generalized geological correlation across the Tibetan Plateau and Himalayan terrane,showing the timing for disappearance of marine strata in the Hi-malayan,Lhasa,and Qiangtang terranes.The initial age of the Siwalik foreland basin is according to ref.46.PQF,marine Pengqu Formation (44);GBC,Gangrin-boche conglomerate;JCLF,Jiachala Formation of tur-bidites (43);HPCMS,Himalayan passive continental margin strata;LZZG,Lingzizhong group volcanics;SXF,shallow marine Sexing Formation (59);TKNF,marine member of the Takena Formation;JZSF,Jingzhushan Formation redbeds;LSF,marine Lang Shan Formation;ABSF,Abushan Formation redbeds;WDLG,continen-tal WG;FHSG-YXCG,FG and YG redbeds;ϩK,K-rich lava;MCT,main central thrust;YZS,Yarlung Tsangpo suture zone;BNS,Bangong–Nujiang suture zone;TTS,Tanggula thrust system.Solid wavy line,nonconfor-mity;dot–dash line,boundary between marine and continentalsediments.Fig.6.Schematic paleogeographic cross sections of the Himalaya and Tibetan Plateau,showing our pro-posed surface-uplift history for the Tibetan Plateau,in which the plateau grows northward and southward from an elevated proto-Tibetan Plateau (Lhasa and Qiangtang terranes)beginning in the Late Paleogene.MBT,main boundary thrust;GCT,great counter thrust;LZZG,Lingzizhong group volcanics;WDLG,continental Wudaoliang Group;TTS,Tanggula thrust system;NKLF,north Kunlun fault;NQF,north Qilian Mountain fault;GBC,Gangrinboche conglomerates;YZS,Yarlung Tsangpo suture zone;BNS,Bangong–Nujiang suture zone;JS,Jinsha River suture zone;MCT,main central thrust;SL,sea level;GT,Gangdese thrust;GST,Gaize–Siling Tso thrust;LB,Lunpola basin;SGAT,Shiquanhe–Gaize–Amdo thrust;SQF,the south Qilian Mountain fault;SB,Siwalik foreland basin;MFT,main frontal thrust.The Yaluzangbu River has been fixed as a reference point.See the A–B line in Fig.1for the position of the 0-Ma cross-section line.Wang et al .PNAS ͉April 1,2008͉vol.105͉no.13͉4991G E O L O GYequations (56)that relate time,temperature,fission-track length,and fission-track density were used to extract age,track-length,and thermal history data.Paleocurrents Direction Determination.Paleocurrent directions were measured from primary sedimentary structures,including cross stratification,pebble imbri-cation,and ripple crest orientation.The orientations of paleocurrent indicators were measured in the field with a Brunton compass.For planar paleocurrent indicators (cross-strata,pebble-cobble imbrication),the strike and dip of the planar feature were measured.Structural restoration of paleocurrent data were made by using a computer-based stereonet program.Radiolarian Biostratigraphy.Ten radiolarian samples were analyzed at the Insti-tute of Geological Sciences (Jagiellonian University,Krakow,Poland).Samples were processed following the procedures described in ref.57.Samples weretreated with 50%hydrochloric acid for 48h to remove calcium carbonate and organic carbon and finely sieved (61m)with water to remove the fine fraction.The radiolarian species present and abundances were recorded following ref.58.ACKNOWLEDGMENTS.We thank Christopher J.L.Wilson and his colleagues at the University of Melbourne (Australia)for the apatite fission track data,and two anonymous reviewers for insightful reviews and constructive suggestions.This work was partially supported by National Key Basic Research Program of China Grant 2006CB701400(to C.W.),111Project of China Grant B07011(to C.W.),and U.S.National Science Foundation Grants EAR0310309(to X.Z.),EAR0511016(to X.Z.),and OCE0327431(to X.Z.).This article is contribution no.492of the Paleo-magnetism Laboratory and Center for the Study of Imaging and Dynamics of the Earth (Institute of Geophysics and Planetary Physics,University of California,Santa Cruz).1.Ruddiman WF,Kutzbach JE (1991)Plateau uplift and climate change.Sci Am 264:66–74.2.Raymo ME,Ruddiman WF (1992)Tectonic forcing of Late Cenozoic climate.Nature 359:117–122.3.An ZS,Kutzbach JE,Prell WL,Porter SC (2001)Evolution of Asian monsoons and phased uplift of the Himalaya-Tibetan Plateau since Late Miocene times.Nature 411:62–66.4.Molnar P,England P,Martinod J (1993)Mantle dynamics,uplift of the Tibetan Plateau,and the Indian Monsoon.Rev Geophys 31:357–396.5.Richter FM,Rowley DB,DePaolo DJ (1992)Sr isotope evolution of seawater:The role of tectonics.Earth Planet Sci Lett 109:11–23.6.Coleman M,Hodges 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关于胚胎干细胞的文献
关于胚胎干细胞的文献
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以色列二穗短柄草谷胱甘肽过氧化物酶活性分析
Ｙ Ｎ Ｊ ｎ’ Ｘ ＥＷ ｎｔｏ， Ｅ Ｙ Ｗ Ｎ ｉ — ｅ ， Ｈ Ｎ ｕ． ａｇ ， Ｈ Ｎ ａ －ｉ （ ． ｏ Ａ ｕ ， Ｕ ｅ— Ｈ ａ ， Ａ ＧＸｎ ｍ ｉ Ｚ Ｏ ＧＧ ｉ ｉｎ 。 Ｃ Ｅ ＧＪ ｎｐｎ ａ ｅ ｇ ｘ ｉ ｇ １ Ｃ１ ．
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要： 二穗短柄草是一种理想的研 究温带禾谷类植物和牧 草的模 式植物。本文对 来源于以 色列 ４个不 同地 区
ｅ ｃ ｓ Ｏ ｈ Ｈ— ｘ ａ ｔｖｔｅ ｆｒｏ ，ｓｅ ａ ｄ ｌａ ａｔ ｆＢ．ｄｉ ａ ｈ ｏ ｒ ｗ ｎ ｔｅ ｎ ｔｒ ｌｍａｉ ｏ － ｎ ｅ ｎ ｔ ｅ ＧＳ Ｐ ｃｉｉ ｓｏ ｏ ｔ ｔｍ ｎ ｅ ｆｐ ｒｓｏ ｉ ｓ ｃ ｙ ｎ ｇ ｅ ｉ ｈ ａｕ ａ ｃｉ ｔ ｃ ｎ ｔ ｌ ｃ
211097944_欧美进口紫花苜蓿可培养种带细菌及其对动植物的致病性
第32卷第4期Vol.32，No.4161-1722023年4月草业学报ACTA PRATACULTURAE SINICA张振粉，黄荣，姚博，等.欧美进口紫花苜蓿可培养种带细菌及其对动植物的致病性.草业学报，2023，32（4）：161−172.ZHANG Zhen-fen，HUANG Rong，YAO Bo，et al.Culturable seed-borne bacteria of lucerne imported from Europe and North America and their pathogenicity to plants and animals.Acta Prataculturae Sinica，2023，32（4）：161−172.欧美进口紫花苜蓿可培养种带细菌及其对动植物的致病性张振粉1，2*，黄荣1，2，姚博1，2，张旺东3，杨成德4，陈秀蓉4（1.甘肃农业大学草业学院，甘肃兰州730070；2.草业生态系统教育部重点实验室，中-美草地畜牧业可持续发展研究中心，甘肃兰州730070；3.甘肃农业大学动物医学院，甘肃兰州730070；4.甘肃农业大学植物保护学院，甘肃兰州730070）摘要：为了探究进口紫花苜蓿种带细菌的多样性及其对动植物的致病性，本研究从北美和欧洲共收集到紫花苜蓿种子样品34份，所有样品经室内研磨稀释分离培养，共获得39株种带细菌分离物，结合常规表型特征及16S rDNA鉴定方法确定它们的分类地位；并在室内采用菌悬液皿内发芽及盆栽接种法和腹腔注射法分别测定了21株代表细菌对供试紫花苜蓿和昆明小鼠的致病性。
结果显示：1）39株细菌隶属3门15属，门分别为厚壁菌门、变形菌门和放线菌门，其中优势门为厚壁菌门；属地位的分别为芽孢杆菌属、假单胞菌属、马赛菌属、短芽孢杆菌属、欧文氏菌属、泛菌属、不动杆菌属、肠杆菌属、埃希氏肠杆菌属、假芽孢杆菌属、假节杆菌属、红球菌属、葡萄球菌属、土壤芽孢杆菌属和微杆菌属，其中优势属为芽孢杆菌属和假单胞菌属。
片段化生境中极小种群野生植物种子传播研究进展
至于无法将携带的种子散播到更远的生境ꎮ 如ꎬ Ｃａｒ￣
法ꎬ 种子 数 量 普 查ꎬ 种 子 捕 捉 器ꎬ 利 用 遗 传 学 进 行
ＤＮＡ 分子技术进行追踪ꎬ 无线电追踪ꎬ 放射性同位素
信号追踪ꎬ 动物活动模型ꎬ 遗传标记等ꎮ
ｉｎｅ Ｅｍｅｒ 等利用元网络的方法在 １６ 个新热带森林片段
中探索了 鸟 类 种 子 传 播 ( Ｂｉｒｄ Ｓｅｅｄ Ｄｉｓｐｅｒｓａｌꎬ ＢＳＤ)
碎化ꎬ 是指原本自然状态下连续的生境在受到人为干
键的生态过程ꎬ 决定了植物的更新模式ꎬ 并影响之后
扰或者自然干扰的情况下ꎬ 生境逐渐由完整发展为支
幼苗的更新生存ꎬ 因此其在生态系统和生物多样性的
离破碎的较小面积生境ꎮ 随着人类社会的不断发展ꎬ
对植物种群的持续性至关重要
[１]
持久中发挥着至关重要的作用 [２] ꎮ 其中极小种群野生
(１ 西南林业大学园林园艺学院ꎬ 云南 昆明 ６５０２２４ꎻ ２ 云南省农业科学院生物技术与种质资源研究所ꎬ 云南 昆明 ６５０２０５)
摘 要: 全球生境碎片化趋势逐渐加深ꎬ 使在碎片化生境中的野生植物受到生存威胁ꎬ 其中包含一些亟需保护的
极小种群野生植物ꎮ 本文主要通过综述片段化生境中植物种子传播过程的研究ꎬ 如片段化生境对种子传播者的影
据营养繁殖物种扩散受限ꎬ 依靠动物传播种子和依靠
程中受到了怎样的影响ꎬ 遇到了哪些困难ꎮ 一起探明
昆虫传播花粉的植物也将受到影响ꎬ 进一步对于植物
物种传播过程中的关键问题ꎬ 为保护极小种群野生植
种群的信息流、 基因流产生一定的影响ꎬ 最终影响到
物提供理论基础ꎮ
物种更新延续和发展 [５] ꎮ
收稿日期: ２０２３－１０－３０
合成生物学
谢谢观看
理论背景
理论背景
合成生物学的研究依据自组织系统结构理论 -泛进化论（structurity, structure theory, panevolution theory），从实证到综合（synthetic ）探讨天然与人工进化的生物系统理论，阐述了结构整合 （integrative）、调适稳态与建构（constructive）层级等规律；因此，系统（systems）生物学也称为“整 合（integrative biology）生物学”，合成（synthetic）生物学又叫“建构生物学（constructive biology）”（Zeng BJ.中译）。系统与合成生物学的系统结构、发生动力与砖块建构、工程设计等基于结构理 论原理，从电脑技术的系统科学理论到遗传工程的系统科学方法，是将物理科学、工程技术原理与方法贯彻到细 胞、遗传机器与细胞通讯技术等纳米层次的生物分子系统分析与设计。
自2000年《自然》（Nature）杂志报道了人工合成基因线路研究成果以来，合成生物学研究在全世界范围 引起了广泛的**与重视，被公认为在医学、制药、化工、能源、材料、农业等领域都有广阔的应用前景。国际上 的合成生物学研究发展飞速，在短短几年内就已经设计了多种基因控制模块，包括开关、脉冲发生器、振荡器等， 可以有效调节基因表达、蛋白质功能、细胞代谢或细胞间相互作用。
合成生物学（synthetic biology），也可翻译成综合生物学，即综合集成，“synthetic”在不同地方翻 译成不同中文，比如综合哲学（synthetic philosophy）、“社会-心理-生物医学模式”的综合（synthetic） 医学（genbrain biosystem network -中科院曾邦哲1999年建于德国，探讨生物系统分析学“biosystem analysis”与人工生物系统“artificial biosystem”，包括实验、计算、系统、工程研究与应用），同时也 被归属为人工生物系统研究的系统生物工程技术范畴，包括生物反应器与生物计算机开发。
地球科学大辞典古生物学
地球科学大辞典古生物学古生物学总论【古生物学】paleontology见84页“古生物学”。
【化石生物学】paleobiology又称现代古生物学。
是对化石进行生物学研究的科学。
作为古生物学的一个新兴分支学科，化石生物学强调化石的生物学意义，从生物学角度，运用生物学的原理和方法来研究化石，涉及演化理论、分类系统、功能形态、生态、遗迹、病理等诸多方面，研究方法和内容远比主要为地质学服务，着重于化石分类描述和生物地层研究的传统古生物学广泛而深刻，研究途径也大为增加。
化石生物学近年来发展很快，取得许多重要进展。
【古动物学】paleozoology古生物学的一个分支学科。
根据保存在地层中的动物化石，研究地史时期动物的形态、构造、分类、生态、分布及进化关系的科学。
又可分为以古无脊椎动物为研究对象的古无脊椎动物学和以古脊椎动物为研究对象的古脊椎动物学。
古动物学对阐明动物界的进化历史、确定地层年代、分析古地理环境、普查勘探各种沉积矿床等都极为重要。
【古无脊椎动物学】invertebrate paleontology又称无脊椎古生物学。
古生物学的一个分支学科。
专门研究地史时期无脊椎动物的科学。
无脊椎动物体内没有由脊椎骨组成的脊柱，神经系统在身体腹侧，心脏在背侧。
无脊椎动物并不是一个正式的动物分类单元，是除脊椎动物亚门以外所有动物的通称，内容十分庞杂，包括门类很多，其中原生动物门、海绵动物门、古杯动物门（现已绝灭）、腔肠动物门、苔藓动物门、腕足动物门、软体动物门、节肢动物门、棘皮动物门等，常形成重要化石。
已知最早的无脊椎动物为伊迪卡拉动物群，均为软躯体动物，寒武纪大量出现了具硬体的无脊椎动物，此后其丰度及分异度便一直占据化石记录的首位，具有极其重要的地质意义，如地质年代表的建立、海相地层地质时代的确定和对比、古环境分析等，均主要依据无脊椎动物化石。
古无脊椎动物研究为阐明生物发展规律、分类系统等提供重要资料。
【古脊椎动物学】vertebrate paleontology古生物学的一个分支学科。
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。
东海厚壳贻贝多糖的抗衰老生物学活性研究的开题报告
东海厚壳贻贝多糖的抗衰老生物学活性研究的开题报告
一、研究背景
随着我国人口老龄化的加剧，抗衰老的研究备受关注。
多糖作为海洋生物中一类重要的天然活性物质，具有很高的生物学活性，被广泛应用在保健、药品等领域。
而
厚壳贻贝是一种常见的贝类，它的厚壳中含有多种多糖，具有抗氧化、抗炎、抗肿瘤
等多种生物学活性。
因此，研究厚壳贻贝中的多糖对于开发新型的抗衰老保健品具有
重要的意义。
二、研究目的和意义
本研究的目的在于从东海厚壳贻贝中提取多糖，并对其进行化学成分分析和抗衰老生物学活性检测，以期为开发新型的抗衰老保健品提供有力支持。
三、研究内容
1. 东海厚壳贻贝多糖的提取和纯化方法的优化：利用常规提取方法和柱层析技术对多糖进行提取和纯化。
2. 多糖成分的分析：利用色谱、光谱等分析方法对多糖进行化学成分分析，分析其单糖组成、分子量等信息。
3. 多糖的抗氧化活性测试：采用体外试验方法，如DPPH自由基清除、还原力等，评价其抗氧化活性。
4. 多糖的抗炎活性测试：采用细胞实验方法，如西红柿红素诱导RAW264.7细
胞产生炎症反应，通过测定促炎性因子(IL-1β、TNF-α等)的生成量，评价多糖的抗炎
活性。
5. 多糖的抗衰老活性测试：采用体外和体内试验方法，如细胞抗氧化实验、老年小鼠模型等，评价多糖的抗衰老活性。
四、研究预期结果
通过对东海厚壳贻贝多糖的提取和纯化，分析其化学成分，并进行抗氧化、抗炎和抗衰老生物学活性检测，预期能够探明其在抗衰老方面的作用机制，为开发新型的
抗衰老保健品提供有力支持。
谢勇博士和美国哈佛医学院专家研究获得β细胞活性肽茶
谢勇博士和美国哈佛医学院专家研究获得β细胞活性肽茶谢勇博士和美国哈佛医学院专家研究获得β细胞活性肽茶β-cell活性肽茶：1992年4月，一封来自大洋彼岸的信寄到了第二军医大学长海医院，信的落款是美国哈佛大学医学院，收到这封来自异国的信函，谢勇心里也充满了疑惑。
打开来信，信的内容让他激动中又有犹豫，信是美国哈佛医学院海外交流中心负责人梅里斯教授写的。
梅里斯教授对谢勇来说并不陌生，他是国际糖尿病联盟的学刊《世界糠尿病》的特约撰稿人，也是国际糖尿病领域著名的学者。
谢勇在参加《世界糖尿病》杂志年会时曾经和梅里斯教授有过交流，梅里斯教授对谢勇在糖尿病方面的一些独特见解十分欣赏。
尤其是谢勇在年会上提出糖尿病不能单独依靠药物治疗的理念更是推崇。
在信中，梅里斯教授代表哈佛医学院邀请他前往该院进行讲学和深入的合作，共同进行糖尿病医学的研究，美国哈佛医学院海外交流中心将让他担任项目负责人，并为他提供可观的研究实验经费。
年轻的谢勇彷徨了，以内心来说，他不愿意离开自己成长学习的地方，更希望能够在自己岗位上为患者治病救人，正如他所说，这是我的责任。
但另一方面，国内的医学科研，无论从硬件设施、政策规定以及其他客观方面都不完善，学术界的论资排辈，研究项目僧多粥少，很多研究资金被无谓的浪费，而一些关键急需的项目却又无从上马，人情、资历、关系都制约着发展。
而美国哈佛医学院海外中心的邀请和承诺，将会是他实现飞跃的一个良好平台。
取舍之间，情理之间，该何去何从？第三天晚上，谢勇来到了导师顾老的家里，他拿着邀请信，把情况告诉了顾老，想征求顾老的意见。
顾老看完信之后，沉默了许久，拿起一柄小锄头到后院的小花园里松土。
当焦急的谢勇快要憋不住时，顾老拿起一块土块放到谢勇的手里，问他：“你的心在那里，你的根在那里，你会丢掉自己的根吗？”谢勇站在那里深思了许久，终于他对顾老坚定地说：我的心是患者，要把他们的病治好，我的根在这里，生养我的土地，我不会改变，我相信自己会回来的！改变时代的发现1992年11月10日，谢勇携带简单的行李，走进了现代医学圣地美国哈佛医学院。
English_Romanticism(英国浪漫主义)
Romantic Fictions
English fiction gropes its way amidst the overwhelming Romantic poetry. It revives its popularity in the hands of Jane Austen & Walter Scott. Walter Scott is noted for his historical novel based on Scottish history and legends. He exerted great influence on European literature of his time.
William Wordsworth
Legend has it that Wordsworth and his sister lived a kind of incestuous life during this period. Dorothy helped Wordsworth turn his eyes to ―the face of nature‖ and ―preserved the poet in him‖. She served as Wordsworth‘s confidante and inspirer. As Wordsworth put it in his poem: She gave me eyes, she gave me ears; And humble cares, and delicate fears; A heart, the fountain of sweet tears;
Overview of Romantic literature
化石对人类的影响英语作文
Fossils have played a significant role in shaping our understanding of the world and the history of life on Earth. They provide a tangible connection to the past, offering insights into the evolution of species, the environment, and the geological changes that have occurred over millions of years. Here are some of the ways in which fossils have impacted humanity:1. Understanding Evolution: Fossils have been instrumental in the development of the theory of evolution. They provide evidence of the gradual changes in species over time, supporting the idea that all life on Earth shares a common ancestry.2. Paleontology: The study of fossils, known as paleontology, has grown into a major scientific discipline. It helps us reconstruct the history of life and the environment of the past, contributing to our knowledge of extinct species and ancient ecosystems.3. Geological Time Scale: Fossils have been crucial in establishing the geological time scale. The presence or absence of certain fossils in rock layers helps geologists determine the relative ages of these layers and understand the sequence of geological events.4. Climate Change: The study of fossilized plants and animals can reveal information about past climates. This information is vital for understanding climate change and its potential impacts on current ecosystems.5. Biodiversity: Fossils help us appreciate the incredible diversity of life that has existed on Earth. They remind us of the many species that have gone extinct and underscore the importance of biodiversity conservation.6. Medical Research: Some fossils, particularly those of ancient human ancestors, have contributed to medical research by providing insights into the evolution of human anatomy and health.7. Cultural and Educational Value: Fossils are a source of fascination and education for people of all ages. They are often displayed in museums and used in educational settings to inspire curiosity and interest in science.8. Economic Impact: The discovery and study of fossils can have economic benefits, such as tourism and the sale of fossil replicas or specimens. Additionally, the oil and gas industry relies on the understanding of geological history, which is informed by the study of fossils.9. Philosophical and Spiritual Impact: The discovery of fossils has challenged and shapedreligious and philosophical views on the origins of life and the Earths history.10. Environmental Awareness: The study of fossils can lead to a greater appreciation of the environment and the need to protect it. It highlights the fragility of ecosystems and the consequences of environmental changes over time.In conclusion, fossils are more than just remnants of ancient life they are a bridge to our past, a key to understanding our present, and a guide for our future. They have significantly influenced science, education, culture, and our perception of the natural world.。
生物化学的发现英文
生物化学的发现英文In the realm of biochemistry, the discovery of DNA's double helix structure stands as a monumental breakthrough.It revolutionized our understanding of genetic informationand paved the way for modern molecular biology.The intricate dance of enzymes and substrates, orchestrating the metabolic pathways within cells, is amarvel of nature's design. Each enzyme, with its unique shape, ensures the specificity and efficiency of biochemical reactions.Another significant revelation in biochemistry is therole of amino acids in protein synthesis. The sequence ofthese building blocks determines the structure and functionof proteins, which are the workhorses of the biological world.The exploration of lipid bilayers and their role in cell membranes has deepened our comprehension of how cellsmaintain their integrity and selectively interact with their environment.The study of biochemistry also unveils the mysteries of cellular energy production. The citric acid cycle andoxidative phosphorylation are processes that convertnutrients into the energy currency of the cell, ATP.Understanding the molecular mechanisms of disease hasbeen greatly advanced by biochemistry. For instance, the identification of the molecular basis of cystic fibrosis has led to more targeted and effective therapies.The emerging field of epigenetics, where biochemistry intersects with genetics, has shed light on how environmental factors can influence gene expression without altering the DNA sequence itself.Finally, the ongoing quest to decode the human proteomeis a testament to the vastness of biochemical knowledge. Each protein's unique function contributes to the symphony of life, and understanding them is key to unlocking the mysteries of health and disease.。
第一腕掌关节置换的研究进展
2023年4月第9卷第4期第一腕掌关节置换的研究进展唐博1，肖海军1，李丛彬21.南方医科大学附属奉贤医院骨科，上海201499；2.安徽理工大学医学院，安徽淮南232001摘要第一腕掌关节置换作为晚期第一腕掌关节炎的治疗手段已经有50余年的历史，因其术后可立即消除疼痛、保持拇腕掌骨的稳定性、提高关节的灵活性，并改善拇指力量等特点，引起大家的广泛关注，但并发症和假体失效情况较为普遍。
然而，随着对第一腕掌关节炎的了解加深和假体设计不断更新，最近的研究显示，第一腕掌关节假体的使用寿命比以往明显提高。
本文综述了近年来第一腕掌关节置换中解剖、生物力学、假体材料、手术技术、围术期评估、术后并发症等方面的研究进展。
关键词第一腕掌关节置换；第一腕掌关节炎；关节假体；生物力学；术后并发症；发展现状中图分类号R4文献标志码A doi10.11966/j.issn.2095-994X.2023.09.04.48Research Progress of First Carpometacarpal Joint ReplacementTANG Bo1, XIAO Haijun1, LI Congbin21. Department of Orthopedics, Fengxian Hospital Affiliated to Southern Medical University, Shanghai, 201499 China;2. School of Medicine, Anhui University of Science and Technology, Huainan, Anhui Province, 232001 ChinaAbstract First carpometacarpal joint replacement has been used as a treatment for late first carpometacarpal osteoarthritis for more than 50 years. Because it can immediately eliminate pain after operation, maintain the stability of the thumb, wrist and metacarpal bone, improve the flexibility of the joint, and improve the strength of the thumb, it has attracted widespread attention, but stituation of complications and pros⁃thetic failure are more common. However, with the deepening understanding of the first carpometacarpal joint and the continuous improve⁃ment of prosthesis design, recent studies have shown that the service life of the first carpometacarpal joint prosthesis is significantly improved than before. This article reviews the research progress in anatomy, biomechanics, prosthetic materials, surgical techniques, perioperative evaluation, and postoperative complications in the first carpometacarpal joint replacement in recent years.Key words First carpometacarpal joint replacement; First carpometacarpal arthritis; Joint prosthesis; Biomechanics; Postoperative complica⁃tions; Development status第一腕掌关节是原发性骨关节炎最常见的发病部位之一，据报道，男性和女性的骨关节炎患病率分别为7%和15%，以中年女性多见[1]。
生物正交化学ppt
生物正交化学的原理
生物正交化学的原理是基于生物体内物质之间相互作用的假 设，即：物质之间存在着种种相互作用，它们可以在生物体 内形成一个紧密联系的网络。 因此，生物正交化学的研究方法是通过分解生物体内物质， 将它们分解为一系列正交的物质，然后分别研究它们彼此之 间的相互作用，从而探索生物体内物质之间的关系和调控机 制。
一、什么是生物正交化学
演讲人 2023-01-14
目录
பைடு நூலகம்
01
什么是生物正交化学
02
生物正交化学的历史
03
生物正交化学的原理
04
生物正交化学的应用
05
生物正交化学的未来发展
什么是生物正交化学
生物正交化学是一种研究生物体内物质之间相互作用的研究方法，它把生 物体内物质分解成一系列正交的物质，然后分别研究其相互作用。生物正 交化学可以用来研究蛋白质、小分子、糖类、脂类和其他生物体内的物质。
谢谢
生物正交化学的历史
生物正交化学的发展始于20世纪30年代，当时，在美国科学家 威廉 普洛斯和亨利 贝克尔的研究中，首次提出了生物正交化学 的概念。他们以抗性调节剂为基础，研究了蛋白质、小分子和 糖类之间的相互作用，从而建立起一个崭新的研究领域。 随后，这一理论在生物领域得到了广泛应用，被用来研究蛋白 质、小分子、糖类和脂类之间的相互作用，从而探索生物体内 物质的调控机制。
生物正交化学的应用
生物正交化学的应用非常广泛，它可以用来研究多种生物体 内物质之间的相互作用，包括蛋白质、小分子、糖类和脂类 等。 此外，生物正交化学还可以用于研究药物的药效学、病毒的 免疫原理、蛋白质的结构和功能、药物的活性机制、细胞信 号转导等。
生物正交化学的未来发展