首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   253篇
  免费   5篇
  国内免费   54篇
  2023年   1篇
  2022年   3篇
  2021年   6篇
  2020年   5篇
  2019年   6篇
  2018年   2篇
  2017年   1篇
  2016年   11篇
  2015年   7篇
  2014年   8篇
  2013年   16篇
  2012年   35篇
  2011年   38篇
  2010年   17篇
  2009年   22篇
  2008年   33篇
  2007年   17篇
  2006年   10篇
  2005年   20篇
  2004年   13篇
  2003年   7篇
  2002年   10篇
  2001年   4篇
  1999年   2篇
  1998年   2篇
  1997年   3篇
  1996年   3篇
  1995年   4篇
  1994年   1篇
  1993年   3篇
  1991年   1篇
  1986年   1篇
排序方式: 共有312条查询结果,搜索用时 15 毫秒
21.
? Premise of the study: Microsatellite markers were developed to help elucidate the population genetics of the invasive species Wedelia trilobata. ? Methods and Results: Using the Fast Isolation by AFLP of Sequences COntaining (FIASCO) repeats protocol, 23 sets of primers for amplifying microsatellite loci were identified in W. trilobata, 10 of which showed polymorphism (two to five alleles per locus) in samples of two populations of W. trilobata, one from China and one from Peru. Six of these loci were successfully amplified from samples of the native congener W. chinensis, with expected sizes. ? Conclusions: These markers may be useful for further investigation of population genetics of Wedelia trilobata and other congener species.  相似文献   
22.
23.
Long  Jun-Yi  Wang  Xue-Jun  Li  Xiao-Ying  Kong  Xie-He  Yang  Guang  Zhang  Dan  Yang  Yan-Ting  Shi  Zheng  Ma  Xiao-Peng 《Neurochemical research》2022,47(3):545-551
Neurochemical Research - Chronic visceral pain (CVP) is one of the common symptoms of many diseases triggered by underlying diseases of the internal organs of the human body. Its causes include...  相似文献   
24.
通过盆栽实验研究丛枝菌根(AM)真菌Glomus versiforme(G.v)、G.mosseae(G.m)、G.intraradices(G.i)、G.aggregatum(G.a)和G.etunicatum(G.e)在锌污染条件下枳实生苗的菌根侵染、生长、叶片和根系锌、磷含量及部分生理指标的影响.结果表明:锌污染...  相似文献   
25.
目的:建立并优化基于Avi-tag标签技术的人胚肾细胞增强型绿色荧光蛋白(eGFP)的定点生物素化标记、纯化和检测方法。方法:分别构建具有Avi-tag标签的eGFP真核表达载体plenti-Avi-eGFP和BirA酶真核过表达载体pQCXIH-BirA,将plenti-Avi-eGFP和pQCXIH-BirA共转染人胚肾293T细胞,12 h后观察Avi-tag标签对eGFP蛋白在细胞内定位的影响;48 h后裂解细胞,用链霉亲和素珠子纯化生物素标记的eGFP,SDS-PAGE观察eGFP纯化和富集情况,并优化基于Western印迹的生物素化eGFP检测方法。结果:Avi-tag标签对eGFP在细胞内的定位无影响,同时BirA酶在293T细胞内可将带Avi-tag标签的eGFP标记上生物素;生物素化的eGFP可特异性地被链霉亲和素珠子纯化和富集,纯度可达95%;Western印迹检测生物素化蛋白的最终条件为5%的BSA作为封闭液和终浓度为100 ng/mL的链霉亲和素-HRP。结论:建立了基于Avi-tag技术的人胚肾细胞内增强型绿色荧光蛋白的生物素化标记、纯化与检测方法,为该方法的广泛应用奠定了前期技术基础。  相似文献   
26.
Molecular phylogeographic studies have recently begun to elucidate how plant species from the Qinghai-Tibetan Plateau (QTP) and adjacent regions responded to the Quaternary climatic oscillations. In this regard, however, far less attention has been paid to the southern and south-eastern declivities of the QTP, i.e. the Himalaya-Hengduan Mountains (HHM) region. Here, we report a survey of amplified fragment length polymorphisms (AFLPs) and chloroplast DNA (cpDNA) sequence variation in the HHM endemic Sinopodophyllum hexandrum, a highly selfing alpine perennial herb with mainly gravity-dispersed berries (105 individuals, 19 localities). We specifically aimed to test a vicariant evolutionary hypothesis across the 'Mekong-Salween Divide', a known biogeographic and phytogeographic boundary of north-to-south trending river valleys separating the East Himalayas and Hengduan Mts. Both cpDNA and AFLPs identified two divergent phylogroups largely congruent with these mountain ranges. There was no genetic depauperation in the more strongly glaciated East Himalayas (AFLPs: H(E)=0.031; cpDNA: h(S)=0.133) compared to the mainly ice-free Hengduan Mts. (AFLPs: H(E)=0.037; cpDNA: h(S)=0.082), while population differentiation was consistently higher in the former region (AFLPs: Φ(ST)=0.522 vs. 0.312; cpDNA: Φ(ST)=0.785 vs. 0.417). Our results suggest that East Himalayan and Hengduan populations of S. hexandrum were once fragmented, persisted in situ during glacials in both areas, and have not merged again, except for a major instance of inter-lineage chloroplast capture identified at the MSD boundary. Our coalescent time estimate for all cpDNA haplotypes (c. 0.37-0.48 mya), together with paleogeological evidence, strongly rejects paleo-drainage formation as a mechanism underlying allopatric fragmentation, whereas mountain glaciers following the ridges of the MSD during glacials (and possible interglacials) could have been responsible. This study thus indicates an important role for mountain glaciers in driving (incipient) allopatric speciation across the MSD in the HHM region by causing vicariant lineage divergence and acting as barriers to post-divergence gene flow.  相似文献   
27.
28.
丛枝菌根真菌对百喜草的生理特性的影响   总被引:1,自引:0,他引:1  
采用盆栽法研究了丛枝菌根(AM)真菌摩西球囊霉(Glomus mosseae)对水分胁迫条件下百喜草(Paspalum notatum)生长、渗透调节及抗氧化酶的影响。结果表明:接种AM真菌显著提高了百喜草的株高、地上部与根部鲜重、地上部P、K、Mn及根部P、Ca、Mn含量,明显降低了地上部Zn及根部Fe、B、Cu水平;随着干旱程度的加深,接种株的地上部相对含水量及叶绿素含量相对稳定且均显著高于未接种株,接种株地上部相对电导率、MDA含量均显著低于未接种株,接种株的地上部POD活性与脯氨酸含量均显著增加且均显著高于未接种株,AM侵染对SOD活性的影响较小。可见,接种AM真菌Glomus mosseae提高了植株体内保护酶活性(如POD)及渗透调节能力(如脯氨酸、P、K、Ca等渗透调节物含量的增加),从而显著增强了百喜草的抗旱性。  相似文献   
29.
The wide adoption of genome-wide association study (GWAS) has dramatically changed the landscape of the genetic studies of human diseases.Banking on the study design that employs large and multiple-independent samples,linkage disequilibrium (LD) -based systematic genome-wide interrogation,and vigorous statistical standard for declaring genetic association,GWAS has greatly advanced the genetic studies of human disease by successfully identifying over 4 thousands of genetic susceptibility SNPs or loci for 210 diseases/traits in human.Besides its unrivaled scientific achievements,GWAS has also transformed the communities of human genetics by stimulating unprecedented broad and large-scale collaboration and data sharing across different groups and countries,which has enabled some mega genetic studies where dozens or hundreds of thousands of samples were investigated through mete-analysis,providing enormous statistical power for discovering genetic variants,even the ones with very moderate effect on disease phenotype or physiological trait.While the success of GWAS has been widely recognized,there are many concerns on GWAS that are being passionately debated.In particular,there ate heated discussions on why only a limited proportion,quiet often a small proportion,of genetic heritability can be explained by the GWAS findings,and whether and how the GWAS findings have really advanced the biological investigation and understanding of disease mechanisms.Concerning these shortcomings of GWAS,many have genuinely questioned the perspective of translating the GWAS findings into clinical practice.To provide a platform to discuss the progresses and shortcomings of GWAS,a nature conference,titled “GWAS 2011:Opportunities and Challenges”,was organized through the collaboration between the Nature Genetics and Anhui Medical University,which was held in Hefei,China on May 19-21,2011.  相似文献   
30.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号