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   2070047篇
  免费   143122篇
  国内免费   4782篇
耳鼻咽喉   29974篇
儿科学   64075篇
妇产科学   60321篇
基础医学   289981篇
口腔科学   60481篇
临床医学   174207篇
内科学   408614篇
皮肤病学   45830篇
神经病学   165036篇
特种医学   82721篇
外国民族医学   749篇
外科学   323652篇
综合类   46550篇
现状与发展   6篇
一般理论   661篇
预防医学   145928篇
眼科学   48471篇
药学   152556篇
  4篇
中国医学   4402篇
肿瘤学   113732篇
  2018年   19108篇
  2016年   16695篇
  2015年   18918篇
  2014年   26783篇
  2013年   41186篇
  2012年   54294篇
  2011年   57543篇
  2010年   34601篇
  2009年   33429篇
  2008年   55350篇
  2007年   59838篇
  2006年   60522篇
  2005年   59040篇
  2004年   57055篇
  2003年   55398篇
  2002年   54457篇
  2001年   95533篇
  2000年   98390篇
  1999年   83552篇
  1998年   22864篇
  1997年   20801篇
  1996年   20289篇
  1995年   19042篇
  1994年   18024篇
  1993年   16779篇
  1992年   65075篇
  1991年   62804篇
  1990年   61557篇
  1989年   59901篇
  1988年   55824篇
  1987年   54788篇
  1986年   52619篇
  1985年   50072篇
  1984年   37502篇
  1983年   31944篇
  1982年   19226篇
  1981年   17285篇
  1979年   35754篇
  1978年   25334篇
  1977年   21918篇
  1976年   20071篇
  1975年   22544篇
  1974年   26804篇
  1973年   25844篇
  1972年   24777篇
  1971年   23079篇
  1970年   21994篇
  1969年   20942篇
  1968年   19772篇
  1967年   18011篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
2.
Graefe's Archive for Clinical and Experimental Ophthalmology - The published online version contains mistake as the author's first name and last name have been interchanged as "Hild...  相似文献   
3.
BACKGROUND The adenoma detection rate(ADR) is inversely associated with the incidence of interval colorectal cancer and serves as a benchmark quality criterion during screening colonoscopy. However, adenoma miss rates reach up to 26% and studies have shown that a second inspection of the right colon in retroflected view(RFV) can increase ADR.AIM To assess whether inspection of the whole colon in RFV compared to standard forward view(SFV) can increase ADR.METHODS Patients presenting for screening or surveillance colonoscopy were invited to participate in this randomized controlled trial and randomized into two arms. In RFV arm colonoscopy was initially performed with SFV, followed by a second inspection of the whole colon in RFV. In the SFV arm first withdrawal was performed with SFV, followed by a second inspection of the whole colon again with SFV. Number, size and morphology of polyps found during first and second inspection in each colonic segment were recorded and all polyps were removed and sent for histopathology in separate containers.RESULTS Two hundred and five patients were randomly assigned to the RFV(n = 101) and SFV(n = 104) arm. In the RFV arm, both polyp detection rate(PDR) and ADR were increased under second inspection in RFV(PDR 1~(st) SFV: 39.8%, PDR 2~(nd)RFV: 46.6%; ADR 1~(st) SFV: 35.2%, ADR 2~(nd) RFV: 42%). Likewise, in the SFV arm,PDR and ADR were increased under second inspection(PDR 1~(st) SFV: 37.5%, PDR 2~(nd) SFV: 46.6%; ADR 1~(st) SFV: 34.1%, ADR 2~(nd)SFV: 44.3%) with no significant differences in ADR and PDR between the SFV and RFV arm. Mean number of adenomas per patient(APP) was increased in the RFV and SFV(APP RFV arm: 1~(st) SFV: 1.71; 2~(nd) RFV: 2.38; APP SFV arm: 1~(st) SFV: 1.83, 2~(nd)SFV:2.2). The majority of adenomas additionally found during second inspection in RFV or in SFV were located in the transverse and left-sided colon and were 5 mm in size.CONCLUSION Second inspection of the whole colon leads to increased adenoma detection with no differences between SFV and RFV. Hence, increased detection is most likely a feature of the second inspection itself but not of the inspection mode.  相似文献   
4.
5.
6.
7.
Sinus venosus atrial septal defect (SV‐ASD) usually coexists with partial anomalous pulmonary vein connection (PAPVC). It is a difficult diagnosis in transthoracic echocardiography (TTE) due to eccentric position of defects. We present a rare case of atypical anatomical variation in PAPVC, which was never described before. Two right pulmonary veins drained into superior vena cava, which overrode SV‐ASD and interatrial septum, a third pulmonary vein into the right atrium. Complete diagnosis could not be set after TTE, nor transesophageal echocardiography, whereas angio‐CT was finally conclusive. This diagnostic approach allowed the surgical planning.  相似文献   
8.
9.
10.
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