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   603494篇
  免费   80700篇
  国内免费   27256篇
耳鼻咽喉   6322篇
儿科学   11816篇
妇产科学   8648篇
基础医学   78754篇
口腔科学   14024篇
临床医学   79178篇
内科学   101372篇
皮肤病学   15159篇
神经病学   41800篇
特种医学   23824篇
外国民族医学   224篇
外科学   66904篇
综合类   72207篇
现状与发展   91篇
一般理论   130篇
预防医学   41174篇
眼科学   16151篇
药学   58876篇
  436篇
中国医学   26689篇
肿瘤学   47671篇
  2024年   1377篇
  2023年   6477篇
  2022年   17224篇
  2021年   24246篇
  2020年   21158篇
  2019年   24594篇
  2018年   25373篇
  2017年   24848篇
  2016年   25381篇
  2015年   32702篇
  2014年   38113篇
  2013年   38081篇
  2012年   44488篇
  2011年   47670篇
  2010年   36446篇
  2009年   28156篇
  2008年   32423篇
  2007年   31010篇
  2006年   29345篇
  2005年   27871篇
  2004年   20491篇
  2003年   19116篇
  2002年   16185篇
  2001年   13730篇
  2000年   13068篇
  1999年   11967篇
  1998年   6650篇
  1997年   6124篇
  1996年   4933篇
  1995年   4610篇
  1994年   3917篇
  1993年   2680篇
  1992年   4080篇
  1991年   3749篇
  1990年   3196篇
  1989年   2842篇
  1988年   2473篇
  1987年   2235篇
  1986年   1990篇
  1985年   1595篇
  1984年   1038篇
  1983年   852篇
  1982年   554篇
  1981年   567篇
  1980年   457篇
  1979年   687篇
  1978年   489篇
  1977年   454篇
  1976年   388篇
  1974年   405篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
101.
102.
目的:观察五白散胶囊治疗慢性消化道出血的疗效.方法:治疗组15例用五白散胶囊治疗,对照组15例用维霉素、果胶铋、止血敏治疗.结果:治疗组总有效率100%,对照组总有效率86.6%,两组比较有显著性差异(P<0.05).结论:五白散胶囊治疗消化道溃疡出血止血功效良好.  相似文献   
103.
PRO 1000 V3型心电监护仪LCD逆变器的升级及注意事项   总被引:1,自引:0,他引:1  
介绍了该型心电监护仪黑屏故障的常见原因,对升级前后的LCD逆变器电路作了对比分析,并详细介绍了升级更换的方法和注意事项。  相似文献   
104.
105.
Degranulating mast cells are increased in the airway smooth muscle (ASM) of asthmatics, where they may influence ASM function. The aim of the present study was to determine whether histamine and tryptase modulate ASM cell granulocyte-macrophage colony-stimulating factor (GM-CSF) and RANTES (regulated on activation, normal T-cell expressed and secreted) release and also to examine which receptors are involved in this release. Confluent, quiescent ASM cells from asthmatic and nonasthmatic donors were treated with histamine (1 microM-100 microM) with and without histamine receptor antagonist pre-treatment, or the protease-activated receptor (PAR)-2 agonists tryptase (0.5-5 nM) and SLIGKV (100 and 400 microM). The cells were then stimulated with interleukin (IL)-1beta and/or tumour necrosis factor (TNF)-alpha (10 ng.mL(-1)) or left unstimulated for 24 h. Release of GM-CSF and RANTES was determined by ELISA and prostaglandin (PG)E(2) measured by enzyme immunoassay. Neither histamine nor tryptase induced ASM GM-CSF or RANTES secretion. However, histamine increased IL-1beta-induced GM-CSF release and markedly reduced TNF-alpha-induced RANTES release by both asthmatic and nonasthmatic cells to a similar extent, but did not modulate PGE(2) release. All changes involved activation of the histamine H1 receptor as they were partially or fully blocked by chlorpheniramine, but not ranitidine. Tryptase, via its proteolytic activity, also potentiated GM-CSF, but not RANTES, release from asthmatic and nonasthmatic ASM cells induced by both cytokines. PAR-2 involvement in the tryptase potentiation was unlikely because SLIGKV had no effect. In conclusion, mast cells, through histamine and tryptase, may locally modulate airway smooth muscle-induced inflammation in asthma.  相似文献   
106.
107.
108.
109.
Abstract – Traumatic dental injuries often occur to the teeth and their supporting tissues and they are the main reasons for emergency visit to a dental clinic. Management of a fracture depends on its position and the extent of root involvement. Horizontal root fractures are not seen frequently and the treatment consists of reduction and long‐term rigid fixation of the coronal segment. The present case demonstrates the successful management of two horizontally fractured maxillary central incisors with a follow‐up period of 9 months.  相似文献   
110.
Selecting an appropriate working correlation structure is pertinent to clustered data analysis using generalized estimating equations (GEE) because an inappropriate choice will lead to inefficient parameter estimation. We investigate the well‐known criterion of QIC for selecting a working correlation structure, and have found that performance of the QIC is deteriorated by a term that is theoretically independent of the correlation structures but has to be estimated with an error. This leads us to propose a correlation information criterion (CIC) that substantially improves the QIC performance. Extensive simulation studies indicate that the CIC has remarkable improvement in selecting the correct correlation structures. We also illustrate our findings using a data set from the Madras Longitudinal Schizophrenia Study. Copyright © 2008 John Wiley & Sons, Ltd.  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