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   1352426篇
  免费   113539篇
  国内免费   6412篇
耳鼻咽喉   16867篇
儿科学   43416篇
妇产科学   36908篇
基础医学   185492篇
口腔科学   36669篇
临床医学   122237篇
内科学   281288篇
皮肤病学   32039篇
神经病学   111749篇
特种医学   55989篇
外国民族医学   275篇
外科学   212750篇
综合类   31710篇
现状与发展   2篇
一般理论   430篇
预防医学   107763篇
眼科学   28439篇
药学   94426篇
  6篇
中国医学   2261篇
肿瘤学   71661篇
  2018年   13672篇
  2017年   10862篇
  2016年   13071篇
  2015年   14542篇
  2014年   20310篇
  2013年   30318篇
  2012年   36991篇
  2011年   39721篇
  2010年   24925篇
  2009年   24385篇
  2008年   37152篇
  2007年   39653篇
  2006年   40781篇
  2005年   39326篇
  2004年   37576篇
  2003年   36646篇
  2002年   34618篇
  2001年   66191篇
  2000年   68021篇
  1999年   56730篇
  1998年   16875篇
  1997年   15152篇
  1996年   16135篇
  1995年   16348篇
  1994年   15201篇
  1993年   14242篇
  1992年   47196篇
  1991年   45850篇
  1990年   44056篇
  1989年   41896篇
  1988年   38829篇
  1987年   38164篇
  1986年   35932篇
  1985年   34708篇
  1984年   26460篇
  1983年   22203篇
  1982年   13964篇
  1981年   12548篇
  1980年   11828篇
  1979年   23619篇
  1978年   17144篇
  1977年   14450篇
  1976年   13266篇
  1975年   13786篇
  1974年   16154篇
  1973年   15454篇
  1972年   14228篇
  1971年   13069篇
  1970年   11913篇
  1969年   11125篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
53.
54.
55.
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   
56.
57.
58.
59.
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   
60.
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   
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