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   1397236篇
  免费   104612篇
  国内免费   4448篇
耳鼻咽喉   17730篇
儿科学   45261篇
妇产科学   38306篇
基础医学   206785篇
口腔科学   37723篇
临床医学   133550篇
内科学   272365篇
皮肤病学   28336篇
神经病学   117055篇
特种医学   49640篇
外国民族医学   368篇
外科学   191599篇
综合类   29069篇
现状与发展   1篇
一般理论   479篇
预防医学   121393篇
眼科学   30529篇
药学   103917篇
  6篇
中国医学   3360篇
肿瘤学   78824篇
  2021年   12099篇
  2019年   13021篇
  2018年   18459篇
  2017年   13574篇
  2016年   14508篇
  2015年   16659篇
  2014年   22467篇
  2013年   34667篇
  2012年   48570篇
  2011年   51174篇
  2010年   29358篇
  2009年   26599篇
  2008年   46218篇
  2007年   48753篇
  2006年   48730篇
  2005年   47145篇
  2004年   44814篇
  2003年   42491篇
  2002年   41156篇
  2001年   62571篇
  2000年   64207篇
  1999年   53732篇
  1998年   14919篇
  1997年   13473篇
  1996年   13346篇
  1995年   12636篇
  1994年   11779篇
  1993年   11042篇
  1992年   42317篇
  1991年   41462篇
  1990年   40079篇
  1989年   37961篇
  1988年   35137篇
  1987年   34253篇
  1986年   32682篇
  1985年   31145篇
  1984年   23419篇
  1983年   19904篇
  1982年   11894篇
  1979年   21216篇
  1978年   15068篇
  1977年   12274篇
  1976年   12103篇
  1975年   12373篇
  1974年   15192篇
  1973年   14838篇
  1972年   13664篇
  1971年   12699篇
  1970年   11804篇
  1969年   10718篇
排序方式: 共有10000条查询结果,搜索用时 281 毫秒
51.
52.
53.
54.
55.
56.
57.
58.
Bipolar disorder (BD) is a common psychiatric mood disorder affecting more than 1-2% of the general population of different European countries. Unfortunately, there is no objective laboratory-based test to aid BD diagnosis or monitor its progression, and little is known about the molecular basis of BD. Here, we performed a comparative proteomic study to identify differentially expressed plasma proteins in various BD mood states (depressed BD, manic BD, and euthymic BD) relative to healthy controls. A total of 10 euthymic BD, 20 depressed BD, 15 manic BD, and 20 demographically matched healthy control subjects were recruited. Seven high-abundance proteins were immunodepleted in plasma samples from the 4 experimental groups, which were then subjected to proteome-wide expression profiling by two-dimensional electrophoresis and matrix-assisted laser desorption/ionization-time-of-flight/time-of-flight tandem mass spectrometry. Proteomic results were validated by immunoblotting and bioinformatically analyzed using MetaCore. From a total of 32 proteins identified with 1.5-fold changes in expression compared with healthy controls, 16 proteins were perturbed in BD independent of mood state, while 16 proteins were specifically associated with particular BD mood states. Two mood-independent differential proteins, apolipoprotein (Apo) A1 and Apo L1, suggest that BD pathophysiology may be associated with early perturbations in lipid metabolism. Moreover, down-regulation of one mood-dependent protein, carbonic anhydrase 1 (CA-1), suggests it may be involved in the pathophysiology of depressive episodes in BD. Thus, BD pathophysiology may be associated with early perturbations in lipid metabolism that are independent of mood state, while CA-1 may be involved in the pathophysiology of depressive episodes.  相似文献   
59.
(+/?)3,4‐methylenedioxymethamphetamine (MDMA, “ecstasy”) is an abused psychostimulant that produces strong monoaminergic stimulation and whole‐body hyperthermia. MDMA‐induced thermogenesis involves activation of uncoupling proteins (UCPs), primarily a type specific to skeletal muscle (UCP‐3) and absent from the brain, although other UCP types are expressed in the brain (e.g. thalamus) and might contribute to thermogenesis. Since neuroimaging of brain temperature could provide insights into MDMA action, we measured spatial distributions of systemically administered MDMA‐induced temperature changes and dynamics in rat cortex and subcortex using a novel magnetic resonance method, Biosensor Imaging of Redundant Deviation in Shifts (BIRDS), with an exogenous temperature‐sensitive probe (thulium ion and macrocyclic chelate 1,4,7,10‐tetraazacyclododecane‐1,4,7,10‐tetramethyl‐1,4,7,10‐tetraacetate (DOTMA4?)). The MDMA‐induced temperature rise was greater in the cortex than in the subcortex (1.6 ± 0.4 °C versus 1.3 ± 0.4 °C) and occurred more rapidly (2.0 ± 0.2 °C/h versus 1.5 ± 0.2 °C/h). MDMA‐induced temperature changes and dynamics in the cortex and body were correlated, although the body temperature exceeded the cortex temperature before and after MDMA. Temperature, neuronal activity, and blood flow (CBF) were measured simultaneously in the cortex and subcortex (i.e. thalamus) to investigate possible differences of MDMA‐induced warming across brain regions. MDMA‐induced warming correlated with increases in neuronal activity and blood flow in the cortex, suggesting that the normal neurovascular response to increased neural activity was maintained. In contrast to the cortex, a biphasic relationship was seen in the subcortex (i.e. thalamus), with a decline in CBF as temperature and neural activity rose, transitioning to a rise in CBF for temperature above 37 °C, suggesting that MDMA affected CBF and neurovascular coupling differently in subcortical regions. Considering that MDMA effects on CBF and heat dissipation (as well as potential heat generation) may vary regionally, neuroprotection may require different cooling strategies. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
60.
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