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   1449197篇
  免费   120175篇
  国内免费   6676篇
耳鼻咽喉   18122篇
儿科学   45871篇
妇产科学   38523篇
基础医学   198162篇
口腔科学   38639篇
临床医学   131814篇
内科学   300593篇
皮肤病学   33228篇
神经病学   120482篇
特种医学   59859篇
外国民族医学   274篇
外科学   227421篇
综合类   33087篇
现状与发展   3篇
一般理论   580篇
预防医学   116997篇
眼科学   30563篇
药学   101720篇
  6篇
中国医学   2386篇
肿瘤学   77718篇
  2018年   15764篇
  2017年   12356篇
  2016年   14602篇
  2015年   16513篇
  2014年   23192篇
  2013年   34717篇
  2012年   43476篇
  2011年   46556篇
  2010年   28683篇
  2009年   27817篇
  2008年   43313篇
  2007年   46226篇
  2006年   47026篇
  2005年   45676篇
  2004年   43645篇
  2003年   42375篇
  2002年   40209篇
  2001年   66979篇
  2000年   68671篇
  1999年   57662篇
  1998年   18031篇
  1997年   16053篇
  1996年   16992篇
  1995年   17121篇
  1994年   15905篇
  1993年   14953篇
  1992年   47657篇
  1991年   46348篇
  1990年   44500篇
  1989年   42318篇
  1988年   39320篇
  1987年   38619篇
  1986年   36415篇
  1985年   35246篇
  1984年   27039篇
  1983年   22822篇
  1982年   14751篇
  1981年   13378篇
  1980年   12513篇
  1979年   24030篇
  1978年   17612篇
  1977年   14880篇
  1976年   13605篇
  1975年   14111篇
  1974年   16460篇
  1973年   15748篇
  1972年   14419篇
  1971年   13279篇
  1970年   12095篇
  1969年   11265篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
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   
62.
63.
64.
65.
66.
Systems of care (SOCs) have been developed throughout the country to meet the needs of children with severe emotional disturbances (SED) and their families. In these SOCs, multiple agencies and disciplines are expected to work together with informal community supports to address families' needs (Stroul & Friedman, 1986a). A review of the literature on the impact of SOCs suggests: (a) communities' service delivery systems change; and (b) children experience modest improvements in symptomatology and functioning. At the same time, little is known about (a) which components of the SOC approach, at what levels, are necessary to impact child and family outcomes; (b) the degree to which SOCs affect other family members, beyond the target child; and (c) the impact of community contexts and supports in SOCs. Future research should improve measurement of key SOC constructs, examine the relation between specific levels of implementation and outcomes for the entire family, and investigate the impact of broader community systems and supports on families within SOCs. © 2004 Wiley Periodicals, Inc. J Comm Psychol 32: 655–674, 2004.  相似文献   
67.
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   
68.
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   
69.
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   
70.
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