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   3620261篇
  免费   262779篇
  国内免费   9461篇
耳鼻咽喉   48981篇
儿科学   120221篇
妇产科学   99691篇
基础医学   509636篇
口腔科学   102494篇
临床医学   332602篇
内科学   706302篇
皮肤病学   85562篇
神经病学   293351篇
特种医学   137571篇
外国民族医学   943篇
外科学   541609篇
综合类   77942篇
现状与发展   8篇
一般理论   1403篇
预防医学   277801篇
眼科学   84005篇
药学   264701篇
  15篇
中国医学   8008篇
肿瘤学   199655篇
  2019年   28821篇
  2018年   41038篇
  2017年   31278篇
  2016年   35576篇
  2015年   40344篇
  2014年   55818篇
  2013年   83446篇
  2012年   112480篇
  2011年   119125篇
  2010年   71303篇
  2009年   67635篇
  2008年   110834篇
  2007年   117952篇
  2006年   119594篇
  2005年   114713篇
  2004年   110496篇
  2003年   106252篇
  2002年   102560篇
  2001年   176028篇
  2000年   180122篇
  1999年   151528篇
  1998年   43134篇
  1997年   37992篇
  1996年   38087篇
  1995年   36932篇
  1994年   33766篇
  1993年   31641篇
  1992年   117263篇
  1991年   113090篇
  1990年   109475篇
  1989年   105791篇
  1988年   96744篇
  1987年   94749篇
  1986年   88942篇
  1985年   84958篇
  1984年   63338篇
  1983年   53745篇
  1982年   31554篇
  1981年   28126篇
  1979年   56022篇
  1978年   39354篇
  1977年   33479篇
  1976年   31239篇
  1975年   33038篇
  1974年   39406篇
  1973年   37667篇
  1972年   35177篇
  1971年   32660篇
  1970年   30195篇
  1969年   28838篇
排序方式: 共有10000条查询结果,搜索用时 312 毫秒
61.
Introduction: In men, lower urinary tract symptoms (LUTS) are primarily attributed to benign prostatic hyperplasia (BPH). Therapeutic options are targeted to relax prostate smooth muscle and/or reduce prostate enlargement.

Areas covered: This article reviews the major preclinical and clinical data on PDE5 inhibitors with a specific focus on tadalafil. It includes details of the role of the nitric oxide (NO)-cyclic guanosine monophosphate (cGMP) – PDE5 pathway in the LUT organs (bladder and prostate) in addition to the available data on tadalafil in patients with LUTS secondary to BPH with or without erectile dysfunction (ED).

Expert opinion: Preclinical and clinical data have clearly demonstrated that PDE5 inhibitors induce bladder and prostate relaxation, which contributes to the improvement seen in storage symptoms in both animal models of bladder and prostate hypercontractility. Tadalafil is effective both as a monotherapy and add-on therapy in patients with LUTS secondary to BPH. Furthermore, as LUTS-BPH and ED are urological disorders that commonly coexist in aging men, tadalafil is more advantageous than α1-adrenoceptors and should be used as the first option. Tadalafil is a safe and tolerable therapy and unlike α1- adrenoceptors and 5-alpha reductase inhibitors, which can cause sexual dysfunctions, tadalafil improves sexual function.  相似文献   

62.
63.
64.
Graefe's Archive for Clinical and Experimental Ophthalmology - The published online version contains mistake as the author's first name and last name have been interchanged as "Hild...  相似文献   
65.
66.
67.
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   
68.
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   
69.
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