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   2640538篇
  免费   203015篇
  国内免费   4996篇
耳鼻咽喉   37858篇
儿科学   84101篇
妇产科学   76328篇
基础医学   372009篇
口腔科学   79620篇
临床医学   229631篇
内科学   513255篇
皮肤病学   58718篇
神经病学   213330篇
特种医学   105545篇
外国民族医学   879篇
外科学   404562篇
综合类   64385篇
现状与发展   9篇
一般理论   920篇
预防医学   196487篇
眼科学   62170篇
药学   199886篇
  7篇
中国医学   5416篇
肿瘤学   143433篇
  2018年   24188篇
  2015年   24386篇
  2014年   33818篇
  2013年   51944篇
  2012年   69014篇
  2011年   72898篇
  2010年   43315篇
  2009年   41459篇
  2008年   70027篇
  2007年   74814篇
  2006年   75833篇
  2005年   73729篇
  2004年   72208篇
  2003年   69607篇
  2002年   68376篇
  2001年   122440篇
  2000年   126206篇
  1999年   107487篇
  1998年   29358篇
  1997年   26678篇
  1996年   26175篇
  1995年   25164篇
  1994年   23646篇
  1993年   22187篇
  1992年   86659篇
  1991年   84050篇
  1990年   82254篇
  1989年   80184篇
  1988年   74661篇
  1987年   73494篇
  1986年   70158篇
  1985年   67318篇
  1984年   50432篇
  1983年   43288篇
  1982年   25719篇
  1981年   23253篇
  1980年   21779篇
  1979年   48326篇
  1978年   34071篇
  1977年   29112篇
  1976年   26854篇
  1975年   29334篇
  1974年   35497篇
  1973年   34242篇
  1972年   32059篇
  1971年   30141篇
  1970年   28169篇
  1969年   26752篇
  1968年   24872篇
  1967年   22392篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
53.
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   
54.
55.
56.
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   
57.
58.
59.
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   
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