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   1338359篇
  免费   112672篇
  国内免费   6372篇
耳鼻咽喉   16706篇
儿科学   43006篇
妇产科学   36554篇
基础医学   183624篇
口腔科学   36273篇
临床医学   120685篇
内科学   278573篇
皮肤病学   31887篇
神经病学   110498篇
特种医学   55534篇
外国民族医学   274篇
外科学   210342篇
综合类   31537篇
现状与发展   2篇
一般理论   414篇
预防医学   106622篇
眼科学   28089篇
药学   93705篇
  5篇
中国医学   2230篇
肿瘤学   70843篇
  2018年   13378篇
  2017年   10630篇
  2016年   12795篇
  2015年   14296篇
  2014年   19944篇
  2013年   29731篇
  2012年   36232篇
  2011年   38880篇
  2010年   24369篇
  2009年   23899篇
  2008年   36358篇
  2007年   38771篇
  2006年   39895篇
  2005年   38484篇
  2004年   36721篇
  2003年   35818篇
  2002年   33830篇
  2001年   66052篇
  2000年   67916篇
  1999年   56587篇
  1998年   16723篇
  1997年   15017篇
  1996年   16014篇
  1995年   16232篇
  1994年   15098篇
  1993年   14153篇
  1992年   47098篇
  1991年   45747篇
  1990年   43970篇
  1989年   41815篇
  1988年   38758篇
  1987年   38081篇
  1986年   35859篇
  1985年   34635篇
  1984年   26358篇
  1983年   22108篇
  1982年   13847篇
  1981年   12447篇
  1980年   11718篇
  1979年   23544篇
  1978年   17072篇
  1977年   14385篇
  1976年   13182篇
  1975年   13722篇
  1974年   16093篇
  1973年   15396篇
  1972年   14173篇
  1971年   13036篇
  1970年   11880篇
  1969年   11102篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
52.
53.
The aim of the present study was to explore differences in the clinical expression, clinical diagnoses and management of airway diseases in a primary-care setting. Patients aged >or=35 yrs who had ever smoked were enrolled when they presented for any reason to one of eight rural primary-care practices. Respiratory symptom questionnaires and spirometry were administered. In total, 1,034 patients had acceptable and reproducible spirometry, of whom 550 (53%) were males and 484 (47%) were females. Males smoked more than females (41.2 versus 29.2 pack-yrs) respectively, and were more likely to have a pre-bronchodilator forced expiratory volume in one second/forced vital capacity <0.70 at 22.4 versus 11.8%, respectively. However, more females than males reported breathlessness (51.0 versus 42.8%, respectively), a prior diagnosis compatible with airflow obstruction and taking respiratory medications (23.4 versus 14.9%, respectively). In conclusion, the current results suggest that females are more likely than males to report breathlessness and be prescribed respiratory medications independent of differences in the severity of airflow obstruction.  相似文献   
54.
55.
56.
57.
For many parents stopping life-sustaining medical treatment on their dying infant is psychologically impossible. Dostoevsky's insights into human behavior, particularly the fact that individuals do not want the anxiety and guilt associated with responsibility for making difficult decisions, might change the way physicians approach parents for permission to withdraw life-prolonging medical interventions on dying infants.  相似文献   
58.
Four clinical trials of porcine islet transplantation have been reported, and there are verbal reports that clinical trials on much larger scales are continuing in centers in China and Russia. The four reported trials are briefly reviewed and, in the light of the present status of experimental islet xenotransplantation, consideration is given to whether such trials are currently justified. The Ethics Committee of the International Xenotransplantation Association has (1) emphasized the need for encouraging studies in non-human primates before clinical trials should be undertaken, (2) mandatory monitoring for the transfer of porcine microorganisms, and (3) careful regulation and oversight by recognized bodies. Other aspects of the topic, such as the need for informed consent, are briefly discussed. We conclude that, at the present time, more data documenting convincing efficacy, focused on clinically applicable immunosuppressive regimens, are needed to justify the initiation of closely monitored clinical trials. A clinical trial may then be justified even though the potential risk to the patients, and possibly for society, will not be zero.  相似文献   
59.
Summary: The mosaic (Atp7a mo-ms ) is an X-linked, lethal mutation in mice. In mosaic mutant males, many clinical features characteristic of defective copper metabolism have been observed and they die at the age of 15 days, exhibiting strongsimilarities to the brindled and macular mutants. About 4% of the mutant males live to sexual maturity and some of them are fertile. In this paper, alterationsin the structure of the kidney from adult mutants are described. Owing to an inherited defect of efflux, copper is accumulated in the kidney of the mutants up to a toxic level and this leads to severe damage of the renal cortex. Pathological changes in the kidney mostly affected the structure of the renal corpuscle and renaltubules.  相似文献   
60.
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