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   5288篇
  免费   309篇
  国内免费   22篇
耳鼻咽喉   47篇
儿科学   183篇
妇产科学   123篇
基础医学   582篇
口腔科学   143篇
临床医学   392篇
内科学   1757篇
皮肤病学   68篇
神经病学   471篇
特种医学   113篇
外科学   661篇
综合类   19篇
一般理论   1篇
预防医学   207篇
眼科学   27篇
药学   361篇
中国医学   7篇
肿瘤学   457篇
  2023年   53篇
  2022年   73篇
  2021年   169篇
  2020年   82篇
  2019年   135篇
  2018年   156篇
  2017年   116篇
  2016年   122篇
  2015年   114篇
  2014年   173篇
  2013年   243篇
  2012年   288篇
  2011年   280篇
  2010年   155篇
  2009年   144篇
  2008年   223篇
  2007年   284篇
  2006年   260篇
  2005年   262篇
  2004年   223篇
  2003年   208篇
  2002年   216篇
  2001年   164篇
  2000年   168篇
  1999年   156篇
  1998年   45篇
  1997年   45篇
  1996年   42篇
  1995年   43篇
  1994年   38篇
  1993年   31篇
  1992年   101篇
  1991年   60篇
  1990年   76篇
  1989年   61篇
  1988年   57篇
  1987年   65篇
  1986年   50篇
  1985年   53篇
  1984年   45篇
  1983年   52篇
  1982年   20篇
  1979年   25篇
  1978年   19篇
  1976年   16篇
  1975年   25篇
  1974年   26篇
  1971年   16篇
  1970年   20篇
  1968年   15篇
排序方式: 共有5619条查询结果,搜索用时 15 毫秒
101.
102.
Since the mechanisms by which specific immunity destroys Her-2/neu carcinoma cells are highly undetermined, these were assessed in BALB/c mice vaccinated with plasmids encoding extracellular and transmembrane domains of the protein product (p185(neu)) of the rat Her-2/neu oncogene shot into the skin by gene gun. Vaccinated mice rejected a lethal challenge of TUBO carcinoma cells expressing p185(neu). Depletion of CD4 T cells during immunization abolished the protection, while depletion of CD8 cells during the effector phase halved it, and depletion of polymorphonuclear granulocytes abolished all protection. By contrast, Ig mu-chain gene KO mice, as well as Fcgamma receptor I/III, beta-2 microglobulin, CD1, monocyte chemoattractant protein 1 (MCP1), IFN-gamma, and perforin gene KO mice were protected. Only mice with both IFN-gamma and perforin gene KOs were not protected. Although immunization also cured all BALB/c mice bearing established TUBO carcinomas, it did not cure any of the perforin KO or perforin and IFN-gamma KO mice. Few mice were cured that had knockouts of the gene for Ig mu-chain, Fcgamma receptor I/III, IFN-gamma, or beta-2 microglobulin. Moreover, vaccination cured half of the CD1 and the majority of the MCP1 KO mice. The eradication of established p185(neu) carcinomas involves distinct mechanisms, each endowed with a different curative potential.  相似文献   
103.
104.
105.
106.
107.
108.
To determine the potential role of emergency surgical revascularization as treatment of acute myocardial infarction (AMI), results in 79 patients undergoing operation for myocardial revascularization during AMI from January 1986 to January 1991 were reviewed. Clinical characteristics for inclusion in the study were: 1) emergency operation; 2) persistent angina not controlled by medical therapy; 3) fixed ST segment elevation until surgical procedure, independently from magnitude of enzymatic levels. The 79 patients were divided in 2 groups: 27 with AMI or evolving AMI (Group 1); 52 with AMI due to complications during PTCA (Group 2). Twenty-eight patients had extremely severe clinical conditions. Mean interval between the beginning of AMI and operation was 4.2 +/- 6.7 hours, with a statistically significant difference between Group 1 (8.7 +/- 10.0) and Group 2 (1.9 +/- 1.0). One hundred ninety-two grafts were performed (2.4 +/- 1.1 grafts/patient). Overall hospital mortality was 10.1% (CL 6.7-13.3) (8 deaths) with a difference between Group 1 [18.5% (CL 10.7-25.3)] and Group 2 [5.8% (CL 4.7-6.6)] (p = 0.074). The incidence of perioperative myocardial infarction was 30.4% (CL 24.9-35.1) for that one in the area of ischemic muscle and 2.6% (CL 0.8-4.1) for infarction in remote muscle. Multivariate analysis for the entire series (79 patients) identified as independent predictors of increased in-hospital mortality: preoperative cardiogenic shock (p = 1.000E-4) and hyperlipidemia (p = 0.008). In Group 1 multivariate analysis identified as independent predictors of increased in-hospital mortality: the attempt of revascularization by PTCA and hyperlipidemia; in Group 2: preoperative need of mechanical ventilatory support.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
109.
110.
FreeSurfer software package automatically estimates the cerebral cortical thickness. Its use is widely accepted, albeit this tool was validated against histologic measurements in only two post-mortem isolated brain MR scans. Indeed, a comparison between histologic measurements and FreeSurfer estimation from in vivo data was never performed. At the “Claudio Munari” Center for Epilepsy and Parkinson Surgery we have included FreeSurfer in our presurgical workflow since 2008, mainly because the automatic reconstruction of the brain surface is useful for carefully planning the surgical resection. We therefore compared cortical thickness values obtained by the automatic software pipeline with manual histologic measurements performed on 27 histologic specimens resected from the corresponding brain regions of the same epileptic subjects. This method-comparison study, including Passing–Bablok regression and Bland-Altman plot analysis, showed a good agreement between FreeSurfer estimation and histologic measurements of cortical thickness. The mean cortical thickness values (±Standard Deviation) obtained with FreeSurfer and histologic measurements were 3.65 mm?±?0.44 and 3.72 mm?±?0.36, respectively (P value?=?0.32). Our findings strengthen previous reports on cortical thickness changes as biomarkers of different neurological conditions.  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