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   1604929篇
  免费   133833篇
  国内免费   2591篇
耳鼻咽喉   21712篇
儿科学   53073篇
妇产科学   46304篇
基础医学   228362篇
口腔科学   47315篇
临床医学   141575篇
内科学   315999篇
皮肤病学   34147篇
神经病学   130587篇
特种医学   64913篇
外国民族医学   474篇
外科学   244414篇
综合类   39789篇
现状与发展   3篇
一般理论   548篇
预防医学   123456篇
眼科学   36628篇
药学   121592篇
  3篇
中国医学   2975篇
肿瘤学   87484篇
  2018年   14858篇
  2016年   12964篇
  2015年   15100篇
  2014年   20754篇
  2013年   31530篇
  2012年   42809篇
  2011年   45055篇
  2010年   26460篇
  2009年   25427篇
  2008年   43221篇
  2007年   45458篇
  2006年   46318篇
  2005年   44906篇
  2004年   44335篇
  2003年   42418篇
  2002年   41530篇
  2001年   75840篇
  2000年   78485篇
  1999年   66510篇
  1998年   17789篇
  1997年   16375篇
  1996年   16353篇
  1995年   16064篇
  1994年   15117篇
  1993年   14265篇
  1992年   55528篇
  1991年   53893篇
  1990年   52661篇
  1989年   50926篇
  1988年   47322篇
  1987年   46652篇
  1986年   44377篇
  1985年   42927篇
  1984年   32095篇
  1983年   27614篇
  1982年   16179篇
  1981年   14472篇
  1980年   13604篇
  1979年   30501篇
  1978年   21112篇
  1977年   17801篇
  1976年   16731篇
  1975年   17602篇
  1974年   21528篇
  1973年   20710篇
  1972年   18883篇
  1971年   17817篇
  1970年   16323篇
  1969年   15298篇
  1968年   13977篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
Owing to the frequent incidence of blast-induced traumatic brain injury (bTBI) in recent military conflicts, there is an urgent need to develop effective therapies for bTBI-related pathologies. Blood-brain barrier (BBB) breakdown has been reported to occur after primary blast exposure, making restoration of BBB function and integrity a promising therapeutic target. We tested the hypothesis that treatment with dexamethasone (DEX) after primary blast injury potentiates recovery of an in vitro BBB model consisting of mouse brain endothelial cells (bEnd.3). DEX treatment resulted in complete recovery of transendothelial electrical resistance and hydraulic conductivity 1 day after injury, compared with 3 days for vehicle-treated injured cultures. Administration of RU486 (mifepristone) inhibited effects of DEX, confirming that barrier restoration was mediated by glucocorticoid receptor signaling. Potentiated recovery with DEX treatment was accompanied by stronger zonula occludens (ZO)-1 tight junction immunostaining and expression, suggesting that increased ZO-1 expression was a structural correlate to BBB recovery after blast. Interestingly, augmented ZO-1 protein expression was associated with specific upregulation of the α+ isoform but not the α isoform. This is the first study to provide a mechanistic basis for potentiated functional recovery of an in vitro BBB model because of glucocorticoid treatment after primary blast injury.  相似文献   
32.
33.
We report on a child with several café au lait spots in association with a lumbar lipomeningomyelocele as an apparently new association. Cutaneous markers, the identification of which plays a crucial role in the early diagnosis and management of spinal malformations, can accompany occult spinal dysraphism. Herein we report a case of lumbar lipomeningomyelocele associated with an overlying café au lait spot that served as a marker of occult spinal dysraphism. The patient also had segmental café au lait spots on the face, making the association unique.  相似文献   
34.
35.
36.
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   
37.
38.
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