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   1453629篇
  免费   101332篇
  国内免费   3179篇
耳鼻咽喉   21639篇
儿科学   44061篇
妇产科学   41201篇
基础医学   203275篇
口腔科学   43959篇
临床医学   119902篇
内科学   291773篇
皮肤病学   34157篇
神经病学   115725篇
特种医学   56385篇
外国民族医学   436篇
外科学   223262篇
综合类   31669篇
现状与发展   6篇
一般理论   471篇
预防医学   103707篇
眼科学   34038篇
药学   108249篇
  3篇
中国医学   3561篇
肿瘤学   80661篇
  2018年   16473篇
  2017年   12326篇
  2016年   13116篇
  2015年   14703篇
  2014年   19931篇
  2013年   30178篇
  2012年   41691篇
  2011年   44121篇
  2010年   25371篇
  2009年   23497篇
  2008年   40964篇
  2007年   44587篇
  2006年   44544篇
  2005年   43310篇
  2004年   41521篇
  2003年   40169篇
  2002年   39296篇
  2001年   67138篇
  2000年   69399篇
  1999年   58452篇
  1998年   15129篇
  1997年   13757篇
  1996年   13232篇
  1995年   12460篇
  1994年   11656篇
  1992年   43923篇
  1991年   42246篇
  1990年   41409篇
  1989年   40261篇
  1988年   37541篇
  1987年   36978篇
  1986年   35472篇
  1985年   33575篇
  1984年   25182篇
  1983年   21314篇
  1982年   12796篇
  1981年   11689篇
  1979年   24230篇
  1978年   17251篇
  1977年   15015篇
  1976年   13571篇
  1975年   15501篇
  1974年   18354篇
  1973年   17876篇
  1972年   17069篇
  1971年   15995篇
  1970年   15168篇
  1969年   14609篇
  1968年   13694篇
  1967年   12233篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
31.
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   
32.
33.
34.
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   
35.
In the current immunosuppressive therapy era, vessel thrombosis is the most common cause of early graft loss after renal transplantation. The prevalence of IgA anti–β2-glycoprotein I antibodies (IgA-aB2GPI-ab) in patients on dialysis is elevated (>30%), and these antibodies correlate with mortality and cardiovascular morbidity. To evaluate the effect of IgA-aB2GPI-ab in patients with transplants, we followed all patients transplanted from 2000 to 2002 in the Hospital 12 de Octubre prospectively for 10 years. Presence of IgA-aB2GPI-ab in pretransplant serum was examined retrospectively. Of 269 patients, 89 patients were positive for IgA-aB2GPI-ab (33%; group 1), and the remaining patients were negative (67%; group 2). Graft loss at 6 months post-transplant was significantly higher in group 1 (10 of 89 versus 3 of 180 patients in group 2; P=0.002). The most frequent cause of graft loss was thrombosis of the vessels, which was observed only in group 1 (8 of 10 versus 0 of 3 patients in group 2; P=0.04). Multivariate analysis showed that the presence of IgA-aB2GPI-ab was an independent risk factor for early graft loss (P=0.04) and delayed graft function (P=0.04). There were no significant differences regarding patient survival between the two groups. Graft survival was similar in both groups after 6 months. In conclusion, patients with pretransplant IgA-aB2GPI-ab have a high risk of early graft loss caused by thrombosis and a high risk of delayed graft function. Therefore, pretransplant IgA-aB2GPI-ab may have a detrimental effect on early clinical outcomes after renal transplantation.  相似文献   
36.
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