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   448863篇
  免费   52954篇
  国内免费   162篇
  2018年   3803篇
  2017年   3506篇
  2016年   5454篇
  2015年   8144篇
  2014年   9154篇
  2013年   12863篇
  2012年   14849篇
  2011年   14952篇
  2010年   9866篇
  2009年   9136篇
  2008年   13049篇
  2007年   13534篇
  2006年   12210篇
  2005年   12046篇
  2004年   11813篇
  2003年   11251篇
  2002年   10742篇
  2001年   21607篇
  2000年   21731篇
  1999年   17251篇
  1998年   6043篇
  1997年   6280篇
  1996年   6071篇
  1995年   5684篇
  1994年   5744篇
  1993年   5563篇
  1992年   13642篇
  1991年   12962篇
  1990年   12629篇
  1989年   12489篇
  1988年   11153篇
  1987年   10778篇
  1986年   9863篇
  1985年   9643篇
  1984年   8182篇
  1983年   7062篇
  1982年   5519篇
  1981年   4998篇
  1980年   4647篇
  1979年   7679篇
  1978年   5911篇
  1977年   5424篇
  1976年   5057篇
  1975年   5361篇
  1974年   5806篇
  1973年   5655篇
  1972年   5102篇
  1971年   4727篇
  1970年   3926篇
  1969年   3848篇
排序方式: 共有10000条查询结果,搜索用时 234 毫秒
1.
2.
3.
4.
5.
Bangar  Yogesh C.  Magotra  A.  Patil  C. S.  Jindal  N. 《Biochemical genetics》2021,59(3):668-677

The present meta-analysis was carried to provide the more reliable estimates of gene frequency and association of Rsa 1 generated candidate genotype of prolactin gene within exon-3 with performance traits in 1198 Indian dairy cows using data from 15 published studies. Six genetic models viz., codominant (AA vs. AB, AA vs. BB and AB vs. BB), dominant (AA+AB vs. BB), completely over dominant (AA+BB vs. AB) and recessive (AA vs. AB+BB) were used to obtain standardized mean difference (SMD) between genotypes. Meta-analysis showed that the gene frequency of A allele (156 bp) was 0.60 (95% confidence interval (CI) 0.54, 0.65). In association analysis, cows with AB genotype [SMD?=?0.65, 95% CI 0.00, 1.30] had significantly (P?<?0.05) higher lactation milk yield (LMY) as compared to BB genotype, whereas AA and AB genotypes had similar trend. Likewise, AA?+?AB also had larger effect [SMD?=?2.31, 95% CI 0.21, 4.10] on LMY as compared to BB. Cows with AB genotype had significantly lower age at first calving (AFC) with small effect [SMD (AA vs. AB)?=?1.38, 95% CI 0.06, 2.70] and medium effect [SMD (AB vs. BB)?=????3.83, 95% CI???6.41,???1.24] as compared to cows with AA and BB genotypes, respectively. This finding was confirmed under dominant and completely over dominant models. In case of fat%, AA genotype showed negative effect (SMD?=????0.51, 95% CI???0.84,???0.17) under recessive model. It was concluded that the propagation of allele A is promising to help dairy farmers to improve the genetic quality of their dairy cows.

  相似文献   
6.
7.
Although much is known about the biochemical regulation of glycolytic enzymes, less is understood about how they are organized inside cells. We systematically examine the dynamic subcellular localization of glycolytic protein phosphofructokinase-1/PFK-1.1 in Caenorhabditis elegans. We determine that endogenous PFK-1.1 localizes to subcellular compartments in vivo. In neurons, PFK-1.1 forms phase-separated condensates near synapses in response to energy stress from transient hypoxia. Restoring animals to normoxic conditions results in cytosolic dispersion of PFK-1.1. PFK-1.1 condensates exhibit liquid-like properties, including spheroid shapes due to surface tension, fluidity due to deformations, and fast internal molecular rearrangements. Heterologous self-association domain cryptochrome 2 promotes formation of PFK-1.1 condensates and recruitment of aldolase/ALDO-1. PFK-1.1 condensates do not correspond to stress granules and might represent novel metabolic subcompartments. Our studies indicate that glycolytic protein PFK-1.1 can dynamically form condensates in vivo.  相似文献   
8.
9.
Silva  M. P.  Rodrigues  C. G.  Varanda  W. A.  Nogueira  R. A. 《Acta biotheoretica》2021,69(4):697-722
Acta Biotheoretica - Ion channels are transport proteins present in the lipid bilayers of biological membranes. They are involved in many physiological processes, such as the generation of nerve...  相似文献   
10.
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