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   16717篇
  免费   1055篇
  国内免费   797篇
  2023年   286篇
  2022年   326篇
  2021年   587篇
  2020年   560篇
  2019年   799篇
  2018年   617篇
  2017年   411篇
  2016年   436篇
  2015年   584篇
  2014年   1157篇
  2013年   1256篇
  2012年   864篇
  2011年   1056篇
  2010年   867篇
  2009年   779篇
  2008年   910篇
  2007年   869篇
  2006年   700篇
  2005年   634篇
  2004年   581篇
  2003年   475篇
  2002年   424篇
  2001年   241篇
  2000年   231篇
  1999年   232篇
  1998年   191篇
  1997年   165篇
  1996年   174篇
  1995年   195篇
  1994年   187篇
  1993年   131篇
  1992年   145篇
  1991年   115篇
  1990年   117篇
  1989年   97篇
  1988年   76篇
  1987年   81篇
  1986年   67篇
  1985年   108篇
  1984年   140篇
  1983年   119篇
  1982年   119篇
  1981年   68篇
  1980年   85篇
  1979年   65篇
  1978年   48篇
  1977年   46篇
  1976年   27篇
  1975年   28篇
  1973年   30篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
13.
《Developmental cell》2023,58(8):694-708.e4
  1. Download : Download high-res image (238KB)
  2. Download : Download full-size image
  相似文献   
14.
Alternative ORFs (AltORFs) are unannotated sequences in genome that encode novel peptides or proteins named alternative proteins (AltProts). Although ribosome profiling and bioinformatics predict a large number of AltProts, mass spectrometry as the only direct way of identification is hampered by the short lengths and relative low abundance of AltProts. There is an urgent need for improvement of mass spectrometry methodologies for AltProt identification. Here, we report an approach based on size-exclusion chromatography for simultaneous enrichment and fractionation of AltProts from complex proteome. This method greatly simplifies the variance of AltProts discovery by enriching small proteins smaller than 40 kDa. In a systematic comparison between 10 methods, the approach we reported enabled the discovery of more AltProts with overall higher intensities, with less cost of time and effort compared to other workflows. We applied this approach to identify 89 novel AltProts from mouse liver, 39 of which were differentially expressed between embryonic and adult mice. During embryonic development, the upregulated AltProts were mainly involved in biological pathways on RNA splicing and processing, whereas the AltProts involved in metabolisms were more active in adult livers. Our study not only provides an effective approach for identifying AltProts but also novel AltProts that are potentially important in developmental biology.  相似文献   
15.
Double-Stranded RNA in Rice   总被引:2,自引:0,他引:2  
Oryza sativa ) and wild rice (O. rufipogon) tissues. It is detected at every developmental stage, and is transmitted very efficiently to progeny via seeds (more than 98%). The dsRNA is maintained at a constant level (approximately 100 copies/cell) in almost all tissues. However, the number of copies increases about 10-fold when host cells are grown in suspension culture. Complete nucleotide sequences of cultivated rice (temperate japonica rice, cv. Nipponbare, J-dsRNA) and wild rice (W-1714, W-dsRNA) dsRNAs have been determined. Both wild and cultivated rice dsRNAs have a single long open reading frame (ORF) containing the conserved motifs of RNA-dependent RNA polymerase and RNA helicase. The coding strands of both contain a site-specific discontinuity (nick) at nt 1,211 (J-dsRNA) or at nt 1,197 (W-dsRNA) from the 5′ end of their coding strand. Rice dsRNA has several unique properties and can be regarded as a novel RNA replicon. This paper discusses the origin and evolution of the rice dsRNA. Received 23 October 1998/ Accepted in revised form 15 December 1998  相似文献   
16.
Cholinergic signaling is crucial in cognitive processes, and degenerating cholinergic projections are a pathological hallmark in dementia. Use of cholinesterase inhibitors is currently the main treatment option to alleviate symptoms of Alzheimer's disease and has been postulated as a therapeutic strategy in acute brain damage (stroke and traumatic brain injury). However, the benefits of this treatment are still not clear. Importantly, cholinergic receptors are expressed both by neurons and by astrocytes and microglia, and binding of acetylcholine to the α7 nicotinic receptor in glial cells results in anti-inflammatory response. Similarly, the brain fine-tunes the peripheral immune response over the cholinergic anti-inflammatory axis. All of these processes are of importance for the outcome of acute and chronic neurological disease. Here, we summarize the main findings about the role of cholinergic signaling in brain disorders and provide insights into the complexity of molecular regulators of cholinergic responses, such as microRNAs and transfer RNA fragments, both of which may fine-tune the orchestra of cholinergic mRNAs. The available data suggest that these small noncoding RNA regulators may include promising biomarkers for predicting disease course and assessing treatment responses and might also serve as drug targets to attenuate signaling cascades during overwhelming inflammation and to ameliorate regenerative capacities of neuroinflammation.

  相似文献   
17.
  相似文献   
18.
19.
《Cell》2021,184(20):5215-5229.e17
  1. Download : Download high-res image (163KB)
  2. Download : Download full-size image
  相似文献   
20.
《Cell》2021,184(25):6037-6051.e14
  1. Download : Download high-res image (153KB)
  2. Download : Download full-size image
  相似文献   
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