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   1486423篇
  免费   102038篇
  国内免费   3242篇
耳鼻咽喉   21808篇
儿科学   44735篇
妇产科学   42134篇
基础医学   208797篇
口腔科学   44930篇
临床医学   121301篇
内科学   295791篇
皮肤病学   34432篇
神经病学   118573篇
特种医学   57336篇
外国民族医学   436篇
外科学   225986篇
综合类   31751篇
现状与发展   6篇
一般理论   459篇
预防医学   110718篇
眼科学   35392篇
药学   111885篇
  4篇
中国医学   3592篇
肿瘤学   81637篇
  2018年   16427篇
  2017年   12464篇
  2016年   13444篇
  2015年   15050篇
  2014年   20191篇
  2013年   30655篇
  2012年   42431篇
  2011年   44861篇
  2010年   25653篇
  2009年   23788篇
  2008年   41737篇
  2007年   45438篇
  2006年   45641篇
  2005年   44073篇
  2004年   42556篇
  2003年   41085篇
  2002年   40227篇
  2001年   67980篇
  2000年   70239篇
  1999年   59158篇
  1998年   15297篇
  1997年   13874篇
  1996年   13340篇
  1995年   12583篇
  1992年   44792篇
  1991年   43062篇
  1990年   42352篇
  1989年   41079篇
  1988年   38424篇
  1987年   37781篇
  1986年   36312篇
  1985年   34430篇
  1984年   25770篇
  1983年   21864篇
  1982年   13085篇
  1981年   11940篇
  1979年   25048篇
  1978年   17806篇
  1977年   15538篇
  1976年   14039篇
  1975年   16065篇
  1974年   19106篇
  1973年   18631篇
  1972年   17846篇
  1971年   16703篇
  1970年   15837篇
  1969年   15335篇
  1968年   14468篇
  1967年   12922篇
  1966年   12063篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
31.
32.
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   
33.
34.
35.
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   
36.
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   
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