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   1211篇
  免费   130篇
  2023年   8篇
  2022年   11篇
  2021年   24篇
  2020年   25篇
  2019年   27篇
  2018年   22篇
  2017年   25篇
  2016年   28篇
  2015年   71篇
  2014年   59篇
  2013年   66篇
  2012年   82篇
  2011年   89篇
  2010年   56篇
  2009年   43篇
  2008年   68篇
  2007年   72篇
  2006年   56篇
  2005年   60篇
  2004年   52篇
  2003年   48篇
  2002年   53篇
  2001年   10篇
  2000年   13篇
  1999年   13篇
  1998年   8篇
  1997年   5篇
  1996年   14篇
  1995年   11篇
  1994年   13篇
  1993年   5篇
  1992年   6篇
  1991年   9篇
  1990年   10篇
  1989年   7篇
  1985年   11篇
  1984年   6篇
  1983年   7篇
  1982年   6篇
  1981年   5篇
  1979年   6篇
  1976年   6篇
  1974年   6篇
  1973年   7篇
  1970年   5篇
  1968年   5篇
  1965年   4篇
  1960年   4篇
  1934年   4篇
  1923年   4篇
排序方式: 共有1341条查询结果,搜索用时 78 毫秒
31.
The role of H-2 in T cell recognition of Mls   总被引:2,自引:0,他引:2  
The role of H-2 was evaluated in T cell recognition of Mls-encoded antigens during primary mixed lymphocyte responses (MLR). Mlsc was used as a stimulating determinant in MLR and its recognition by T cells was assessed by linear regression analysis under culture conditions in which (A x B)F1 responder cell number was the factor limiting total response. Results of such experiments indicated the presence of distinct (A x B)F1 responder T cell subpopulations capable of differentially recognizing the foreign Mls antigen in association with one or the other parental H-2 haplotype. These findings demonstrate that T cells do not recognize Mlsc products in isolation, but rather are restricted to recognition of Mlsc in the context of "self" H-2 determinants.  相似文献   
32.
Preliminary studies using an improved method for the agarose gel electrophoresis of semipurified, cleared lysates of staphylococci have indicated some distinct differences in plasmid composition between the coagulase-positive speciesStaphylococcus aureus andStaphylococcus intermedius, and various coagulase-negative species. Penicillinase-positive strains ofS. intermedius andS. simulans did not carry large penicillinase plasmids like most penicillinase-positive strains ofS. aureus. Most coagulase-negative species examined demonstrated complex plasmid profiles. Codigestion by the restriction endonucleasesHaeIII andHpaI offered a useful approach for “fingerprinting” large plasmids from various strains and species.  相似文献   
33.
34.
35.
Interpretation of high‐throughput sequence data requires an understanding of how decisions made during bioinformatic data processing can influence results. One source of bias that is often cited is PCR clones (or PCR duplicates). PCR clones are common in restriction site‐associated sequencing (RAD‐seq) data sets, which are increasingly being used for molecular ecology. To determine the influence PCR clones and the bioinformatic handling of clones have on genotyping, we evaluate four RAD‐seq data sets. Data sets were compared before and after clones were removed to estimate the number of clones present in RAD‐seq data, quantify how often the presence of clones in a data set causes genotype calls to change compared to when clones were removed, investigate the mechanisms that lead to genotype call changes and test whether clones bias heterozygosity estimates. Our RAD‐seq data sets contained 30%–60% PCR clones, but 95% of RAD‐tags had five or fewer clones. Relatively few genotypes changed once clones were removed (5%–10%), and the vast majority of these changes (98%) were associated with genotypes switching from a called to no‐call state or vice versa. PCR clones had a larger influence on genotype calls in individuals with low read depth but appeared to influence genotype calls at all loci similarly. Removal of PCR clones reduced the number of called genotypes by 2% but had almost no influence on estimates of heterozygosity. As such, while steps should be taken to limit PCR clones during library preparation, PCR clones are likely not a substantial source of bias for most RAD‐seq studies.  相似文献   
36.
Neurochemical Research - Gamma-decanolactone (GD) has been shown to reduce epileptic behavior in different models, inflammatory decreasing, oxidative stress, and genotoxic parameters. This study...  相似文献   
37.
The International Journal of Life Cycle Assessment - The flexibility of life cycle inventory (LCI) background data selection is increasing with the increasing availability of data, but this comes...  相似文献   
38.
39.
40.
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