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   2418733篇
  免费   174319篇
  国内免费   3520篇
耳鼻咽喉   33160篇
儿科学   77795篇
妇产科学   64496篇
基础医学   357425篇
口腔科学   65734篇
临床医学   215874篇
内科学   472371篇
皮肤病学   53678篇
神经病学   190830篇
特种医学   89333篇
外国民族医学   491篇
外科学   361879篇
综合类   47846篇
现状与发展   12篇
一般理论   869篇
预防医学   191263篇
眼科学   55957篇
药学   180487篇
  11篇
中国医学   4777篇
肿瘤学   132284篇
  2021年   20237篇
  2019年   21034篇
  2018年   29567篇
  2017年   21899篇
  2016年   24177篇
  2015年   27281篇
  2014年   37837篇
  2013年   56761篇
  2012年   79613篇
  2011年   84366篇
  2010年   49559篇
  2009年   46342篇
  2008年   78578篇
  2007年   83650篇
  2006年   84306篇
  2005年   81802篇
  2004年   78044篇
  2003年   75052篇
  2002年   72535篇
  2001年   110127篇
  2000年   112964篇
  1999年   94627篇
  1998年   27255篇
  1997年   23820篇
  1996年   24244篇
  1995年   22828篇
  1994年   21016篇
  1993年   19808篇
  1992年   72639篇
  1991年   70676篇
  1990年   68960篇
  1989年   66203篇
  1988年   60774篇
  1987年   59630篇
  1986年   55706篇
  1985年   53441篇
  1984年   39695篇
  1983年   33685篇
  1982年   19995篇
  1979年   36268篇
  1978年   25902篇
  1977年   21421篇
  1976年   20563篇
  1975年   22064篇
  1974年   26542篇
  1973年   25169篇
  1972年   23534篇
  1971年   22330篇
  1970年   20611篇
  1969年   19633篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
OBJECTIVE: To determine whether under-reporting of rheumatic fever occurs at hospital, municipal, provincial and national levels of the South African health system. BACKGROUND: Information on the incidence of rheumatic fever (RF) and the prevalence of rheumatic heart disease (RHD) is required for the prevention of valvular heart disease in developing countries. In South Africa, RF was made a notifiable condition in 1989. It has recently been suggested that the reporting of RF cases may be incomplete, possibly because of underreporting by health care professionals and deficient administration of the disease notification system in South Africa. METHOD AND RESULTS: We assessed whether underreporting of RF cases occurs by comparing the numbers of RF cases reported per year at hospital, municipal, provincial and national levels from 1990 to 2004. There was a fall in the number of RF cases reported per year at national and provincial level over the 15 years of observation. A detailed analysis of the number of RF cases reported at hospital, municipal and provincial level for a 5-year period showed that more cases were diagnosed in one hospital (serving a smaller population) than were captured at municipal and provincial level (serving a larger population), suggesting underreporting by health care professionals. There were discrepancies in the number of cases reported at municipal, provincial and national level, suggesting poor administration of the notification system. CONCLUSION: There appears to be underreporting of RF cases by health care professionals, and poor administration of the RF notification system. Health care professionals need to be educated about the statutory requirement to notify all RF cases in South Africa. An effective national disease notification system is required.  相似文献   
93.
94.
95.
Traumatic injuries of the elbow are frequent in patients of all ages but are particularly common in young children and adolescents engaged in normal play and athletic competition. Injury may result primarily due to direct trauma or may be secondary to transmission of forces through the elbow following a fall on an outstretched hand. In middle-aged and older individuals, chronic repetitive injuries tend to predominate. In all patients, radiographs remain the initial imaging study of choice. Many patients, however, may need advanced cross-sectional imaging (i.e. MRI, CT, or ultrasound) either at presentation or during the course of their treatment and follow-up. This article reviews the imaging appearance of common acute and chronic traumatic disorders of the elbow.  相似文献   
96.
97.
Both vascular surgery and endovascular interventions traumatise the arterial wall, especially the endothelium. The vessel responds with neointimal hyperplasia and/or constrictive remodelling, and this is still the limiting factor in curative interventions. Stent placement prevents constrictive remodelling but is the main trigger for in-stent restenosis. Hyperproliferation of neointimal tissue is the main response to arterial thrombosis, local inflammation or medio-intimal injury such as occurs, for example, after balloon dilatation in the region of arterial anastomoses or of a thrombectomy (Fogarty-manoeuvre). At present, research on prevention of restenosis is focused on inhibiting neointimal hyperproliferation by using drug-eluting stents, and especially sirolimus- or paclitaxel-eluting stents. In addition, further experimental research work is in progress, with the aim of esablishing new treatment regimens and solving the problem of neointimal formation, thrombosis and constrictive remodelling. These include both local and systemic pharmacological therapy, brachy- and laser therapy, and many genetic treatment options, some of which are currently the subjects of experimental studies and early-stage clinical trials. Gene therapy seems like a promising way of preventing restenosis, but has not yet been tested in clinical trials. In the near future, selective, simultaneous, and perhaps even polyphasic regulation for gene silencing of two or more genes involved in the development of restenosis could improve the long-term patency rate.  相似文献   
98.
99.
100.
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