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   2281篇
  免费   206篇
  国内免费   2篇
  2023年   6篇
  2022年   13篇
  2021年   30篇
  2020年   24篇
  2019年   17篇
  2018年   39篇
  2017年   34篇
  2016年   60篇
  2015年   109篇
  2014年   128篇
  2013年   130篇
  2012年   175篇
  2011年   154篇
  2010年   104篇
  2009年   102篇
  2008年   142篇
  2007年   150篇
  2006年   172篇
  2005年   144篇
  2004年   114篇
  2003年   123篇
  2002年   136篇
  2001年   23篇
  2000年   18篇
  1999年   22篇
  1998年   33篇
  1997年   20篇
  1996年   29篇
  1995年   23篇
  1994年   31篇
  1993年   18篇
  1992年   25篇
  1991年   14篇
  1990年   11篇
  1989年   17篇
  1988年   12篇
  1987年   7篇
  1986年   6篇
  1985年   13篇
  1983年   6篇
  1982年   5篇
  1981年   4篇
  1980年   7篇
  1978年   4篇
  1976年   9篇
  1975年   3篇
  1972年   3篇
  1971年   3篇
  1965年   2篇
  1951年   2篇
排序方式: 共有2489条查询结果,搜索用时 0 毫秒
161.
A series of novel biphenyl pyrazole dicarboxamides were identified as potential sodium channel blockers for treatment of neuropathic pain. Compound 20 had outstanding efficacy in the Chung rat spinal nerve ligation (SNL) model of neuropathic pain.  相似文献   
162.
2‐DE reference maps for Deinococcus geothermalis cytosolic and cell envelope proteomes were constructed. In total, 403 spots were identified as 299 different proteins. Unique in the proteomes were four subunits of V‐type ATPase and Deinococcus specific proteins constituting one‐fourth of cell envelope proteome. The cytoplasmic proteome included enzymes of the central carbon metabolism, chaperones, enzymes of protein and DNA repair, and oxidative stress. A total of 34 abundant proteins with unknown function may relate to the extreme stress tolerance of D. geothermalis.  相似文献   
163.
164.
165.

Background  

Free-living wild rodents are often used as zoomonitors of environmental contamination. In the present study, accumulation of cadmium (Cd), copper (Cu), iron (Fe), and zinc (Zn) in critical organs of yellow-necked mice (Apodemus flavicollis) and bank voles (Myodes glareolus) trapped in a polluted area in Nováky, Slovakia was investigated.  相似文献   
166.
Artemisinin from Artemisia annua has become one of the most important drugs for malaria therapy. Its biosynthesis proceeds via amorpha-4,11-diene, but it is still unknown whether the isoprenoid precursors units are obtained by the mevalonate pathway or the more recently discovered non-mevalonate pathway. In order to address that question, a plant of A. annua was grown in an atmosphere containing 700 ppm of 13CO2 for 100 min. Following a chase period of 10 days, artemisinin was isolated and analyzed by 13C NMR spectroscopy. The isotopologue pattern shows that artemisinin was predominantly biosynthesized from (E,E)-farnesyl diphosphate (FPP) whose central isoprenoid unit had been obtained via the non-mevalonate pathway. The isotopologue data confirm the previously proposed mechanisms for the cyclization of (E,E)-FPP to amorphadiene and its oxidative conversion to artemisinin. They also support deprotonation of a terminal allyl cation intermediate as the final step in the enzymatic conversion of FPP to amorphadiene and show that either of the two methyl groups can undergo deprotonation.  相似文献   
167.

Introduction  

Pristane-induced arthritis (PIA) in the rat has been described as an animal model of inflammatory arthritis which exhibits features similar to rheumatoid arthritis in humans, such as a chronic, destructive, and symmetrical involvement of peripheral joints. However, so far little is known about the earliest inflammatory events and their influence on locomotor behaviour during the course of PIA. To investigate this issue a detailed analysis of the pathologic changes occurring during the prodromal and early stages of PIA was performed.  相似文献   
168.

Introduction  

Neutrophils and monocytes play an important role in overt inflammation in chronic inflammatory joint diseases such as rheumatoid arthritis (RA). The sympathetic nervous system (SNS) inhibits many neutrophil/monocyte functions and macrophage tumor necrosis factor (TNF), but because of the loss of sympathetic nerve fibers in inflamed tissue, sympathetic control is attenuated. In this study, we focused on noradrenergic and TNF regulation of human neutrophil peptides 1-3 (HNP1-3), which are proinflammatory bactericidal α-defensins.  相似文献   
169.
170.
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