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   1739087篇
  免费   141401篇
  国内免费   2963篇
耳鼻咽喉   23551篇
儿科学   57390篇
妇产科学   49207篇
基础医学   246286篇
口腔科学   53788篇
临床医学   151347篇
内科学   345418篇
皮肤病学   37636篇
神经病学   141730篇
特种医学   69019篇
外国民族医学   498篇
外科学   260843篇
综合类   40877篇
现状与发展   4篇
一般理论   598篇
预防医学   138048篇
眼科学   39069篇
药学   129611篇
  3篇
中国医学   3508篇
肿瘤学   95020篇
  2018年   18914篇
  2017年   14691篇
  2016年   15747篇
  2015年   18370篇
  2014年   25359篇
  2013年   37239篇
  2012年   51722篇
  2011年   54394篇
  2010年   31270篇
  2009年   29604篇
  2008年   50280篇
  2007年   53068篇
  2006年   53238篇
  2005年   52104篇
  2004年   51108篇
  2003年   48501篇
  2002年   45985篇
  2001年   78968篇
  2000年   81680篇
  1999年   69394篇
  1998年   18911篇
  1997年   17309篇
  1996年   17275篇
  1995年   16823篇
  1994年   15869篇
  1993年   14997篇
  1992年   57232篇
  1991年   55517篇
  1990年   54223篇
  1989年   52483篇
  1988年   48769篇
  1987年   47962篇
  1986年   45579篇
  1985年   44088篇
  1984年   32934篇
  1983年   28312篇
  1982年   16580篇
  1981年   14810篇
  1979年   31168篇
  1978年   21548篇
  1977年   18131篇
  1976年   17000篇
  1975年   18011篇
  1974年   21917篇
  1973年   21118篇
  1972年   19215篇
  1971年   18088篇
  1970年   16671篇
  1969年   15625篇
  1968年   14298篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
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   
52.
53.
54.
55.
56.

Background

Resistin is an immunometabolic mediator that is elevated in several inflammatory disorders. A ligand for Toll-like receptor 4, resistin modulates the recruitment and activation of myeloid cells, notably neutrophils. Neutrophils are major drivers of cystic fibrosis (CF) lung disease, in part due to the release of human neutrophil elastase- and myeloperoxidase-rich primary granules, leading to tissue damage. Here we assessed the relationship of resistin to CF lung disease.

Methods

Resistin levels were measured in plasma and sputum from three retrospective CF cohorts spanning a wide range of disease. We also assessed the ability of neutrophils to secrete resistin upon activation in vitro. Finally, we constructed a multivariate model assessing the relationship between resistin levels and lung function.

Results

Plasma resistin levels were only marginally higher in CF than in healthy control subjects. By contrast, sputum resistin levels were very high in CF, reaching 50–100 fold higher levels than in plasma. Among CF patients, higher plasma resistin levels were associated with allergic bronchopulmonary aspergillosis, and higher sputum resistin levels were associated with CF-related diabetes. Mechanistically, in vitro release of neutrophil primary granules was concomitant with resistin secretion. Overall, sputum resistin levels were negatively correlated with CF lung function, independently of other variables (age, sex, and genotype).

Conclusions

Our data establish relationships between resistin levels in the plasma and sputum of CF patients that correlate with disease status, and identify resistin as a novel mechanistic link between neutrophilic inflammation and lung disease in CF.  相似文献   
57.
58.
59.
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