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   248553篇
  免费   36890篇
  国内免费   3156篇
耳鼻咽喉   6249篇
儿科学   8317篇
妇产科学   4890篇
基础医学   16531篇
口腔科学   3668篇
临床医学   34387篇
内科学   68667篇
皮肤病学   9376篇
神经病学   24120篇
特种医学   10203篇
外国民族医学   23篇
外科学   54085篇
综合类   1882篇
现状与发展   72篇
一般理论   50篇
预防医学   12602篇
眼科学   4873篇
药学   9095篇
  3篇
中国医学   523篇
肿瘤学   18983篇
  2024年   734篇
  2023年   5214篇
  2022年   2325篇
  2021年   5067篇
  2020年   7215篇
  2019年   3960篇
  2018年   9491篇
  2017年   8923篇
  2016年   10109篇
  2015年   10368篇
  2014年   18076篇
  2013年   19404篇
  2012年   10652篇
  2011年   10859篇
  2010年   13702篇
  2009年   17126篇
  2008年   10433篇
  2007年   8836篇
  2006年   11060篇
  2005年   8130篇
  2004年   7631篇
  2003年   6444篇
  2002年   6570篇
  2001年   7475篇
  2000年   6640篇
  1999年   6147篇
  1998年   4746篇
  1997年   4319篇
  1996年   4148篇
  1995年   3969篇
  1994年   2612篇
  1993年   2211篇
  1992年   3133篇
  1991年   3151篇
  1990年   2538篇
  1989年   2611篇
  1988年   2331篇
  1987年   2028篇
  1986年   2049篇
  1985年   1740篇
  1984年   1304篇
  1983年   1208篇
  1982年   954篇
  1981年   786篇
  1980年   708篇
  1979年   875篇
  1978年   742篇
  1977年   763篇
  1975年   706篇
  1972年   723篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
33.
Rat brain hippocampal slices were incubated with or without the convulsant 4-aminopyridine (4-AP). From these slices a crude mitochondrial/synaptosomal membrane fraction was prepared and analyzed for endogenous protein phosphorylation. 4-AP (10(-5) M) stimulated the phosphorylation of a 50 kDa protein by 86%. The phosphorylation of this 50 kDa protein is Ca2+/calmodulin-dependent and we suggest that this protein is the lower molecular weight subunit of Ca2+/calmodulin-dependent protein kinase II (CaMK II).  相似文献   
34.
35.
36.
This paper reports the proceedings of the discussion panel assigned to look at clinical aspects of quality in emergency medicine. One of the seven stated objectives of the Academic Emergency Medicine consensus conference on quality in emergency medicine was to educate emergency physicians regarding quality measures and quality improvement as essential aspects of the practice of emergency medicine. Another topic of interest was a discussion of the value of information technology in facilitating quality care in the clinical practice of emergency medicine. It is important to note that this is not intended to be a comprehensive review of this extensive topic, but instead is designed to report the discussion that occurred at this session of the consensus conference.  相似文献   
37.
Female rats consistently show a pattern of differences in defensive behaviors compared to males which parallel the effects of exposure to a nonpainful threat stimulus (cat or cat odor) in the same tests and measures. These indications of greater defensiveness for females are particularly common in situations involving potential, as opposed to actual and present, threat, a factor which probably also reflects ceiling or floor effects in situations involving very intense defensiveness. In addition, pharmacological studies indicate sex differences in the effects of selective serotonin (5-HT) receptor agonists and antagonists on defensive responding. These findings indicate that sex effects must be considered in studies of the pharmacological control of defensive behaviors, and suggest that responsivity to sex effects may be an additional criterion for the suitability of animal models of anxiety.  相似文献   
38.
Is interleukin 2 a neuromodulator in the brain?   总被引:5,自引:0,他引:5  
A bidirectional flow of information exists between the CNS and the neuroendocrine and immune systems, representing an important homeostatic mechanism in the body. Lymphokines and other products of immunocompetent cells seem to play a crucial role in this communication and seem to exert powerful effects on neurones in the brain. In this article, Giuseppe Nisticò and Giovambattista De Sarro describe the central effects following interleukin 2 (IL-2) microinfusion into several areas of the rat brain. The locus coeruleus seems to be the main site in the brain through which IL-2 exerts soporific effects. In addition, the possible transducing mechanisms coupling IL-2 receptor stimulation and the electroencephalogram (EEG) spectrum power responses elicited from the locus coeruleus seem to involve stimulation of specific receptors coupled to adenylate cyclase through a Gi protein.  相似文献   
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