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   1674729篇
  免费   138301篇
  国内免费   3275篇
耳鼻咽喉   22489篇
儿科学   55235篇
妇产科学   48099篇
基础医学   237799篇
口腔科学   48912篇
临床医学   147126篇
内科学   330995篇
皮肤病学   35710篇
神经病学   137126篇
特种医学   67551篇
外国民族医学   492篇
外科学   254414篇
综合类   41231篇
现状与发展   3篇
一般理论   588篇
预防医学   127369篇
眼科学   37683篇
药学   127323篇
  5篇
中国医学   3426篇
肿瘤学   92729篇
  2018年   16403篇
  2016年   14266篇
  2015年   16635篇
  2014年   22726篇
  2013年   34414篇
  2012年   46555篇
  2011年   48977篇
  2010年   29076篇
  2009年   27713篇
  2008年   46695篇
  2007年   49106篇
  2006年   49700篇
  2005年   48113篇
  2004年   47791篇
  2003年   45822篇
  2002年   44935篇
  2001年   78325篇
  2000年   80815篇
  1999年   68431篇
  1998年   18599篇
  1997年   17011篇
  1996年   16920篇
  1995年   16593篇
  1994年   15589篇
  1993年   14718篇
  1992年   56607篇
  1991年   54979篇
  1990年   53592篇
  1989年   51857篇
  1988年   48097篇
  1987年   47378篇
  1986年   45117篇
  1985年   43589篇
  1984年   32583篇
  1983年   28068篇
  1982年   16486篇
  1981年   14725篇
  1980年   13826篇
  1979年   30878篇
  1978年   21376篇
  1977年   18054篇
  1976年   16967篇
  1975年   17900篇
  1974年   21852篇
  1973年   21034篇
  1972年   19174篇
  1971年   18060篇
  1970年   16563篇
  1969年   15525篇
  1968年   14208篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
41.
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   
42.
43.
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   
44.
45.
46.
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   
47.
48.
49.
50.
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