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   3514866篇
  免费   304859篇
  国内免费   14110篇
耳鼻咽喉   47883篇
儿科学   112558篇
妇产科学   92347篇
基础医学   560988篇
口腔科学   93772篇
临床医学   316615篇
内科学   627620篇
皮肤病学   93289篇
神经病学   303530篇
特种医学   137839篇
外国民族医学   491篇
外科学   541036篇
综合类   107579篇
现状与发展   24篇
一般理论   2337篇
预防医学   294694篇
眼科学   80515篇
药学   241470篇
  20篇
中国医学   10473篇
肿瘤学   168755篇
  2021年   55150篇
  2020年   35145篇
  2019年   58163篇
  2018年   71621篇
  2017年   54381篇
  2016年   60192篇
  2015年   74004篇
  2014年   108284篇
  2013年   173399篇
  2012年   98974篇
  2011年   99439篇
  2010年   117872篇
  2009年   122267篇
  2008年   86236篇
  2007年   89879篇
  2006年   100335篇
  2005年   95606篇
  2004年   97053篇
  2003年   87481篇
  2002年   76932篇
  2001年   118130篇
  2000年   111584篇
  1999年   107531篇
  1998年   66645篇
  1997年   64233篇
  1996年   62077篇
  1995年   57522篇
  1994年   51467篇
  1993年   48036篇
  1992年   74200篇
  1991年   69870篇
  1990年   65614篇
  1989年   64406篇
  1988年   59370篇
  1987年   58082篇
  1986年   54621篇
  1985年   54419篇
  1984年   49488篇
  1983年   45062篇
  1982年   42167篇
  1981年   39544篇
  1980年   37235篇
  1979年   40224篇
  1978年   35568篇
  1977年   32276篇
  1976年   29615篇
  1975年   27938篇
  1974年   29007篇
  1973年   28030篇
  1972年   26229篇
排序方式: 共有10000条查询结果,搜索用时 234 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