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   954063篇
  免费   65604篇
  国内免费   2526篇
耳鼻咽喉   13108篇
儿科学   30004篇
妇产科学   27101篇
基础医学   134094篇
口腔科学   26075篇
临床医学   79905篇
内科学   193946篇
皮肤病学   19808篇
神经病学   76691篇
特种医学   39367篇
外国民族医学   343篇
外科学   149801篇
综合类   19649篇
一般理论   287篇
预防医学   68647篇
眼科学   21471篇
药学   67451篇
中国医学   1924篇
肿瘤学   52521篇
  2018年   10059篇
  2017年   7982篇
  2016年   8668篇
  2015年   9879篇
  2014年   13984篇
  2013年   21449篇
  2012年   28952篇
  2011年   30833篇
  2010年   18610篇
  2009年   17697篇
  2008年   29491篇
  2007年   31207篇
  2006年   31314篇
  2005年   30834篇
  2004年   29474篇
  2003年   28590篇
  2002年   28014篇
  2001年   42020篇
  2000年   43156篇
  1999年   36968篇
  1998年   10645篇
  1997年   9696篇
  1996年   9559篇
  1995年   8892篇
  1994年   8459篇
  1993年   7947篇
  1992年   28595篇
  1991年   27343篇
  1990年   26737篇
  1989年   25701篇
  1988年   23866篇
  1987年   23493篇
  1986年   22535篇
  1985年   21470篇
  1984年   16134篇
  1983年   13798篇
  1982年   8434篇
  1981年   7386篇
  1979年   14843篇
  1978年   10467篇
  1977年   8866篇
  1976年   8336篇
  1975年   9159篇
  1974年   10894篇
  1973年   10344篇
  1972年   9818篇
  1971年   9021篇
  1970年   8698篇
  1969年   8126篇
  1968年   7777篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
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   
2.
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.
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   
7.
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