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   1358994篇
  免费   102337篇
  国内免费   6314篇
耳鼻咽喉   16952篇
儿科学   43820篇
妇产科学   36582篇
基础医学   200574篇
口腔科学   36263篇
临床医学   132789篇
内科学   261430篇
皮肤病学   26520篇
神经病学   113065篇
特种医学   48999篇
外国民族医学   384篇
外科学   186754篇
综合类   32994篇
现状与发展   5篇
一般理论   461篇
预防医学   116031篇
眼科学   29621篇
药学   101442篇
  28篇
中国医学   4529篇
肿瘤学   78402篇
  2021年   12097篇
  2019年   12434篇
  2018年   17123篇
  2017年   13002篇
  2016年   13991篇
  2015年   16280篇
  2014年   22151篇
  2013年   33213篇
  2012年   45842篇
  2011年   48756篇
  2010年   28279篇
  2009年   25886篇
  2008年   43943篇
  2007年   46338篇
  2006年   46390篇
  2005年   44835篇
  2004年   42333篇
  2003年   40369篇
  2002年   38965篇
  2001年   61357篇
  2000年   63088篇
  1999年   52955篇
  1998年   15015篇
  1997年   13714篇
  1996年   13432篇
  1995年   12752篇
  1994年   11921篇
  1993年   11085篇
  1992年   41757篇
  1991年   40923篇
  1990年   39579篇
  1989年   37469篇
  1988年   34686篇
  1987年   33784篇
  1986年   32210篇
  1985年   30697篇
  1984年   23053篇
  1983年   19602篇
  1982年   11762篇
  1979年   20820篇
  1978年   14814篇
  1977年   12064篇
  1976年   11876篇
  1975年   12110篇
  1974年   14801篇
  1973年   14472篇
  1972年   13356篇
  1971年   12418篇
  1970年   11485篇
  1969年   10410篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
993.
994.
995.
996.
997.
998.
Several case reports have implicated Ginkgo biloba in clinically adverse bleeding disorders. Ginkgo biloba has been reported to increase pain-free walking distance among patients with peripheral artery disease (PAD). Standard PAD therapy includes 325 mg/day aspirin. The objective of this study was to examine potential adverse effects of concomitant aspirin and Ginkgo biloba on platelet function. Ginkgo biloba (EGb 761, 300 mg/day) was compared with placebo for effects on measures of platelet aggregation among adults consuming 325 mg/day aspirin in a randomized, double-blind, placebo-controlled, parallel design trial of 4-week duration. Participants were adults, age 69 +/- 10 years, with PAD or risk factors for cardiovascular disease. Outcome measures included platelet function analysis (PFA-100 analyzer) using ADP as an agonist (n = 26 placebo; n = 29 ginkgo), and platelet aggregation using ADP, epinephrine, collagen and ristocetin as agonists (n = 21 placebo; n = 23 ginkgo). Participants kept daily logs of bleeding or bruising episodes. There were no clinically or statistically significant differences between treatment groups for any agonists, for either PFA-100 analysis or platelet aggregation. Reports of bleeding or bruising were infrequent and similar for both study groups. In conclusion, in older adults with PAD or cardiovascular disease risk, a relatively high dose of Ginkgo biloba combined with 325 mg/day daily aspirin did not have a clinically or statistically detectable impact on indices of coagulation examined over 4 weeks, compared with the effect of aspirin alone. No adverse bleeding events were observed, although the trial was limited to a small sample size.  相似文献   
999.
Facial hemiatrophies are anomalies of the first branchial arch and affect one in 4000-5000 newborns. Bone distraction is the technique of choice for the treatment of these dysmorphoses. Mandibular osteodistraction requires prior determination of the characteristics of the distraction vector whose three components will serve to activate the distractor. The patient, aged 5 years, presented with a right facial hemiatrophy, Grade IB according to the classification of Pruzansky. Tomodensitometric acquisition was obtained with a CT scanner. Software specifically designed for this application allows segmentation of the anatomical elements by a region-growing algorithm. The 3D representation of each element is added to a 3D scene, in which are placed the built-up landmarks necessary for the surgical simulation after 3D cephalometric analysis. The surgical cleavage plane is oriented according to the surgeon's requirements while preserving the predominant anatomical elements. The software allows performance of rotations and translations of the bone segments rendered independently from the cleavage plane. The distances and angles covered during the virtual movement are measured at its conclusion. The aim of moving the bone segments is to render the mandibular occlusion plane parallel to the reference occlusion plane. The vertical growth of the maxilla is realized by secondary recuperation. The distractor used was of an external multidirectional type allowing elongation of the mandibular ramus and mandibular corpus, closure of the goniac angle, and lateralization or medialization of the ramus. On the 15th day, the mandibular angle was reduced by 10 degrees, which allowed closure of the anterior gap and recentering of the incisive areas by a half-cuspid. The patient presented with a complex bone deficit in the three spatial directions, which allowed the development of software for modeling the distraction. Other clinical cases will be necessary to validate this 3D imaging-based technique.  相似文献   
1000.
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