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   1600302篇
  免费   133581篇
  国内免费   2578篇
耳鼻咽喉   21661篇
儿科学   52940篇
妇产科学   46229篇
基础医学   227824篇
口腔科学   47245篇
临床医学   140956篇
内科学   314974篇
皮肤病学   34117篇
神经病学   130150篇
特种医学   64754篇
外国民族医学   474篇
外科学   243920篇
综合类   39713篇
现状与发展   3篇
一般理论   544篇
预防医学   122876篇
眼科学   36474篇
药学   121296篇
  3篇
中国医学   2974篇
肿瘤学   87334篇
  2018年   14773篇
  2016年   12921篇
  2015年   15040篇
  2014年   20668篇
  2013年   31366篇
  2012年   42565篇
  2011年   44784篇
  2010年   26350篇
  2009年   25315篇
  2008年   43015篇
  2007年   45268篇
  2006年   46074篇
  2005年   44699篇
  2004年   44122篇
  2003年   42207篇
  2002年   41313篇
  2001年   75698篇
  2000年   78346篇
  1999年   66407篇
  1998年   17738篇
  1997年   16339篇
  1996年   16319篇
  1995年   16029篇
  1994年   15074篇
  1993年   14222篇
  1992年   55446篇
  1991年   53795篇
  1990年   52585篇
  1989年   50845篇
  1988年   47234篇
  1987年   46578篇
  1986年   44298篇
  1985年   42858篇
  1984年   32045篇
  1983年   27576篇
  1982年   16146篇
  1981年   14437篇
  1980年   13566篇
  1979年   30471篇
  1978年   21070篇
  1977年   17769篇
  1976年   16700篇
  1975年   17579篇
  1974年   21492篇
  1973年   20677篇
  1972年   18860篇
  1971年   17777篇
  1970年   16297篇
  1969年   15278篇
  1968年   13956篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
43.
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   
44.
45.
46.
47.

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   
48.
49.
50.
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