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   1336111篇
  免费   100230篇
  国内免费   4276篇
耳鼻咽喉   16801篇
儿科学   43640篇
妇产科学   36404篇
基础医学   197921篇
口腔科学   35912篇
临床医学   129637篇
内科学   258218篇
皮肤病学   26376篇
神经病学   111889篇
特种医学   48204篇
外国民族医学   366篇
外科学   184133篇
综合类   28776篇
现状与发展   1篇
一般理论   460篇
预防医学   114390篇
眼科学   28987篇
药学   98964篇
  6篇
中国医学   3170篇
肿瘤学   76362篇
  2021年   10933篇
  2019年   11655篇
  2018年   16339篇
  2017年   12303篇
  2016年   13264篇
  2015年   15217篇
  2014年   20840篇
  2013年   32088篇
  2012年   44305篇
  2011年   46934篇
  2010年   27100篇
  2009年   24959篇
  2008年   42771篇
  2007年   45104篇
  2006年   45224篇
  2005年   43641篇
  2004年   41591篇
  2003年   39532篇
  2002年   38336篇
  2001年   60871篇
  2000年   62542篇
  1999年   52294篇
  1998年   14585篇
  1997年   13279篇
  1996年   13123篇
  1995年   12461篇
  1994年   11626篇
  1993年   10924篇
  1992年   41584篇
  1991年   40772篇
  1990年   39459篇
  1989年   37343篇
  1988年   34590篇
  1987年   33706篇
  1986年   32161篇
  1985年   30648篇
  1984年   23046篇
  1983年   19597篇
  1982年   11754篇
  1979年   20804篇
  1978年   14814篇
  1977年   12064篇
  1976年   11876篇
  1975年   12110篇
  1974年   14800篇
  1973年   14472篇
  1972年   13356篇
  1971年   12418篇
  1970年   11487篇
  1969年   10413篇
排序方式: 共有10000条查询结果,搜索用时 0 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