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   1354047篇
  免费   113468篇
  国内免费   6408篇
耳鼻咽喉   16836篇
儿科学   43533篇
妇产科学   37043篇
基础医学   185688篇
口腔科学   36556篇
临床医学   122863篇
内科学   281139篇
皮肤病学   32196篇
神经病学   112120篇
特种医学   55881篇
外国民族医学   274篇
外科学   211974篇
综合类   31656篇
现状与发展   3篇
一般理论   440篇
预防医学   108664篇
眼科学   28454篇
药学   94657篇
  5篇
中国医学   2251篇
肿瘤学   71690篇
  2018年   13770篇
  2017年   10892篇
  2016年   13079篇
  2015年   14653篇
  2014年   20411篇
  2013年   30502篇
  2012年   37238篇
  2011年   39953篇
  2010年   24986篇
  2009年   24391篇
  2008年   37358篇
  2007年   39759篇
  2006年   40928篇
  2005年   39509篇
  2004年   37713篇
  2003年   36754篇
  2002年   34769篇
  2001年   66180篇
  2000年   68017篇
  1999年   56724篇
  1998年   16885篇
  1997年   15167篇
  1996年   16166篇
  1995年   16384篇
  1994年   15223篇
  1993年   14281篇
  1992年   47213篇
  1991年   45871篇
  1990年   44065篇
  1989年   41917篇
  1988年   38838篇
  1987年   38159篇
  1986年   35931篇
  1985年   34719篇
  1984年   26456篇
  1983年   22191篇
  1982年   13964篇
  1981年   12521篇
  1980年   11786篇
  1979年   23591篇
  1978年   17114篇
  1977年   14412篇
  1976年   13207篇
  1975年   13752篇
  1974年   16120篇
  1973年   15425篇
  1972年   14196篇
  1971年   13054篇
  1970年   11898篇
  1969年   11121篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
62.
63.
64.
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   
65.
66.
67.
68.
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   
69.
70.
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