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   384166篇
  免费   25460篇
  国内免费   3136篇
耳鼻咽喉   5219篇
儿科学   8272篇
妇产科学   10223篇
基础医学   53840篇
口腔科学   11855篇
临床医学   30824篇
内科学   79236篇
皮肤病学   8605篇
神经病学   27573篇
特种医学   14162篇
外国民族医学   85篇
外科学   61152篇
综合类   10792篇
现状与发展   2篇
一般理论   66篇
预防医学   17733篇
眼科学   9577篇
药学   31633篇
  6篇
中国医学   2481篇
肿瘤学   29426篇
  2021年   2953篇
  2019年   2977篇
  2018年   4769篇
  2017年   3633篇
  2016年   3679篇
  2015年   4340篇
  2014年   6048篇
  2013年   7683篇
  2012年   10520篇
  2011年   10698篇
  2010年   6468篇
  2009年   6039篇
  2008年   9706篇
  2007年   10538篇
  2006年   10487篇
  2005年   9604篇
  2004年   8929篇
  2003年   8666篇
  2002年   8307篇
  2001年   28353篇
  2000年   28865篇
  1999年   23752篇
  1998年   5211篇
  1997年   4299篇
  1996年   3877篇
  1995年   3518篇
  1994年   3156篇
  1993年   2861篇
  1992年   16087篇
  1991年   14852篇
  1990年   14184篇
  1989年   13986篇
  1988年   12600篇
  1987年   12084篇
  1986年   11113篇
  1985年   10335篇
  1984年   6928篇
  1983年   5604篇
  1982年   2726篇
  1979年   5482篇
  1978年   3357篇
  1977年   2974篇
  1975年   2643篇
  1974年   3066篇
  1973年   2875篇
  1972年   2834篇
  1971年   2777篇
  1970年   2513篇
  1969年   2547篇
  1968年   2254篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
11.
12.
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   
13.
14.
15.
Nevo  N.  Goldstein  A. L.  Staierman  M.  Eran  N.  Carmeli  I.  Rayman  S.  mnouskin  Y. 《Hernia》2022,26(6):1491-1499
Hernia - The minimally invasive surgical repair of combined inguinal and ventral hernias often requires shifting from one approach or plane to another. The traditional enhanced-view totally...  相似文献   
16.
17.
18.
19.
Porocarcinoma is an unusual, locally aggressive and potentially fatal neoplasm. Several cutaneous malignancies have been described in association with porocarcinoma, including squamous cell carcinoma, basal cell carcinoma and tricholemmal carcinoma. Previous reports have indicated that the occurrence of malignant tumours in combination with porocarcinoma is extremely rare, in particular with regard to Bowen disease (BD). We report an uncommon case of porocarcinoma occurring synchronously in a single BD lesion in a 63‐year‐old woman with multiple BD lesions. The clinical and histological findings confirmed this diagnosis.  相似文献   
20.
In the 6th Basic Plan for Long-Term Electricity Supply and Demand (6th BPE) for Korea, for the first time, the environmental costs of air pollution caused by oxides of sulfur (SOx), oxides of nitrogen (NOx), and particulate matters (PM) from power plants were estimated and included. However, several deficiencies in evaluating the environmental costs were found. In this study, (1) the validity of the environmental costs used in the 6th BPE was assessed, (2) a systematic approach was suggested and used to improve the environmental costs estimation, and (3) the sensitivity of the cost of generating electricity to the environmental costs by fuel type with the proposed approach was discussed. We found that the applied environmental costs used in the 6th BPE did not fully include the demographic characteristics of Korea. By applying more realistic parameter values, it was found that the newly estimated environmental cost was about 23 times higher than the cost estimated in the original 6th BPE for coal-fired power plants and about 1.5 times higher for liquefied natural gas (LNG)-fired power plants, suggesting that LNG-fired power plants are more economical if using more realistic environmental costs. Thus, it is critical to check the validity of parameter values when calculating environmental costs.  相似文献   
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