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   3321803篇
  免费   284196篇
  国内免费   13934篇
耳鼻咽喉   45615篇
儿科学   106504篇
妇产科学   84963篇
基础医学   533769篇
口腔科学   89000篇
临床医学   300329篇
内科学   582658篇
皮肤病学   89771篇
神经病学   288246篇
特种医学   130454篇
外国民族医学   341篇
外科学   514812篇
综合类   101993篇
现状与发展   24篇
一般理论   2380篇
预防医学   279611篇
眼科学   76805篇
药学   227036篇
  20篇
中国医学   9453篇
肿瘤学   156149篇
  2021年   55506篇
  2020年   35444篇
  2019年   58454篇
  2018年   71720篇
  2017年   54433篇
  2016年   60223篇
  2015年   74192篇
  2014年   108621篇
  2013年   174345篇
  2012年   95076篇
  2011年   95796篇
  2010年   118160篇
  2009年   122011篇
  2008年   82481篇
  2007年   85739篇
  2006年   96223篇
  2005年   91752篇
  2004年   93652篇
  2003年   84380篇
  2002年   73853篇
  2001年   94818篇
  2000年   87272篇
  1999年   89017篇
  1998年   64776篇
  1997年   62695篇
  1996年   60368篇
  1995年   55877篇
  1994年   50169篇
  1993年   46685篇
  1992年   62546篇
  1991年   59644篇
  1990年   56711篇
  1989年   56108篇
  1988年   51766篇
  1987年   51159篇
  1986年   48270篇
  1985年   48815篇
  1984年   45436篇
  1983年   41709篇
  1982年   40855篇
  1981年   38651篇
  1980年   36336篇
  1979年   37165篇
  1978年   33856篇
  1977年   31044篇
  1976年   28552篇
  1975年   26874篇
  1974年   27665篇
  1973年   26606篇
  1972年   24702篇
排序方式: 共有10000条查询结果,搜索用时 421 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