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   431694篇
  免费   30050篇
  国内免费   7263篇
耳鼻咽喉   5693篇
儿科学   8683篇
妇产科学   10580篇
基础医学   59241篇
口腔科学   12534篇
临床医学   37659篇
内科学   85733篇
皮肤病学   8962篇
神经病学   30035篇
特种医学   15953篇
外国民族医学   126篇
外科学   65634篇
综合类   19862篇
现状与发展   8篇
一般理论   68篇
预防医学   21044篇
眼科学   10823篇
药学   37005篇
  64篇
中国医学   5756篇
肿瘤学   33544篇
  2022年   3051篇
  2021年   5354篇
  2020年   3789篇
  2019年   4591篇
  2018年   6456篇
  2017年   5151篇
  2016年   5202篇
  2015年   6646篇
  2014年   8734篇
  2013年   9939篇
  2012年   13956篇
  2011年   14450篇
  2010年   8896篇
  2009年   7892篇
  2008年   12151篇
  2007年   13048篇
  2006年   13030篇
  2005年   11906篇
  2004年   10781篇
  2003年   10746篇
  2002年   10147篇
  2001年   29860篇
  2000年   30117篇
  1999年   24941篇
  1998年   6108篇
  1997年   5144篇
  1996年   4490篇
  1995年   4147篇
  1994年   3693篇
  1993年   3131篇
  1992年   16381篇
  1991年   15087篇
  1990年   14373篇
  1989年   14158篇
  1988年   12720篇
  1987年   12167篇
  1986年   11198篇
  1985年   10400篇
  1984年   6941篇
  1983年   5619篇
  1982年   2732篇
  1979年   5486篇
  1978年   3349篇
  1977年   2972篇
  1975年   2641篇
  1974年   3064篇
  1973年   2865篇
  1972年   2828篇
  1971年   2773篇
  1969年   2543篇
排序方式: 共有10000条查询结果,搜索用时 15 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