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   3137363篇
  免费   271613篇
  国内免费   13712篇
耳鼻咽喉   43622篇
儿科学   99707篇
妇产科学   81349篇
基础医学   506581篇
口腔科学   84125篇
临床医学   276930篇
内科学   552164篇
皮肤病学   85697篇
神经病学   271885篇
特种医学   125184篇
外国民族医学   361篇
外科学   495845篇
综合类   96583篇
现状与发展   23篇
一般理论   2167篇
预防医学   260685篇
眼科学   70967篇
药学   213917篇
  17篇
中国医学   9192篇
肿瘤学   145687篇
  2021年   54541篇
  2020年   34833篇
  2019年   57774篇
  2018年   70170篇
  2017年   53178篇
  2016年   58723篇
  2015年   73031篇
  2014年   107063篇
  2013年   172111篇
  2012年   83920篇
  2011年   82909篇
  2010年   114136篇
  2009年   119438篇
  2008年   70810篇
  2007年   72807篇
  2006年   83891篇
  2005年   79897篇
  2004年   81840篇
  2003年   73243篇
  2002年   63329篇
  2001年   89201篇
  2000年   81793篇
  1999年   84933篇
  1998年   63412篇
  1997年   61768篇
  1996年   59481篇
  1995年   54926篇
  1994年   49122篇
  1993年   45914篇
  1992年   58542篇
  1991年   55222篇
  1990年   52398篇
  1989年   51791篇
  1988年   48342篇
  1987年   47252篇
  1986年   45301篇
  1985年   45491篇
  1984年   43088篇
  1983年   39916篇
  1982年   39838篇
  1981年   37588篇
  1980年   35553篇
  1979年   35091篇
  1978年   32153篇
  1977年   29699篇
  1976年   27279篇
  1975年   25794篇
  1974年   26283篇
  1973年   25045篇
  1972年   23562篇
排序方式: 共有10000条查询结果,搜索用时 402 毫秒
131.
132.
133.
134.
135.
136.
Coronary embolism (CE) is an uncommon and unique cause of acute myocardial infarction. In this report, we review 216 cases of CE including 2 new cases from our institution. The mean patient age was 52.5 years and 62% of the patients were males. Chest pain was the most common presenting symptom followed by dyspnea, and the most commonly affected vessel was the left anterior descending artery. Leading etiologies of the embolus were atrial fibrillation, septic emboli, and iatrogenic causes. Treatment approaches varied with thrombus aspiration being used in 30% of cases. In-hospital mortality rate was 36% and 13% of the cases were complicated by cerebrovascular accident. CE is a unique pathology that leads to acute myocardial infarction. It portends a high mortality rate and requires a high level of suspicion as symptoms may be misleading. Further research is needed in order to improve recognition and management and to lower associated mortality.  相似文献   
137.
Academic output is just one aspect of a successful career as a plastic surgeon. However, for those with a strong interest in academia, the academic output of a department will likely be a key factor when deciding how to rank jobs. The aim of this study was to quantify and rank the academic output of plastic surgery units across the UK and Ireland. The Institute for Scientific Information (ISI) Web of Science Bibliometric analysis tool was used to collate cumulative (1950–2016), 10 year (2006–2016) and 3 years (2013–2015) research output data for plastic surgery units in the UK and Ireland. Sixty-six plastic surgery units were identified. Departments were ranked for each time period according to the number of papers produced, number of citations (Nc) and h-index (a measure of the impact of scientific output). The top 3 departments for number of papers in the last 10 years were The Royal Free Hospital, London (226) Broomfield Hospital, Chelmsford (218), and Morriston Hospital and Swansea (188). The top 3 for h-number were The Royal Free Hospital (21) Wythenshawe Hospital, Manchester (18) and Morriston Hospital (17). Academic output varies across plastic surgery units in the UK and Ireland. A number of departments have consistently maintained high academic outputs across the years and will be of interest to surgeons hoping to pursue a career in academia.  相似文献   
138.
There is a sharp difference in how one views TCR structure–function–behaviour dependent on whether its recognition of major histocompatibility complex‐encoded restriction elements (R) is germline selected or somatically generated. The generally accepted or Standard model is built on the assumption that recognition of R is by the V regions of the αβ TCR, which is not driven by allele specificity, whereas the competing model posits that recognition of R is allele‐specific. The establishing of allele‐specific recognition of R by the TCR would rule out the Standard model and clear the road to a consideration of a competing construct, the Tritope model. Here, the case for allele‐specific recognition (germline selected) is detailed making it obvious that the Standard model is untenable.  相似文献   
139.
140.
Krishna S. Iyer 《Platelets》2020,31(4):474-482
Abstract

Platelets are small, anucleated effector cells that play an important role in linking the hemostatic and inflammatory processes in the body. Platelet function is known to be altered under various inflammatory conditions including aging. A gain in platelet function during aging can increase the risk of thrombotic events, such as stroke and acute myocardial infarction. Anti-platelet therapy is designed to reduce risk of serious cerebrovascular and cardiovascular events, but the adverse consequences of therapy, such as risk for bleeding increases with aging as well. Age-associated comorbidities such as obesity, diabetes, and hyperlipidemia also contribute to increased platelet activity and thus can enhance the risk of thrombosis. Therefore, identification of unique mechanisms of platelet dysfunction in aging and in age-associated comorbidities is warranted to design novel antiplatelet drugs. This review outlines some of the current areas of research on aging-related mechanisms of platelet hyperactivity and addresses the clinical urgency for designing anti-platelet therapies toward novel molecular targets in the aging population.  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