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   3618023篇
  免费   262377篇
  国内免费   9473篇
耳鼻咽喉   48875篇
儿科学   120231篇
妇产科学   99557篇
基础医学   509522篇
口腔科学   102250篇
临床医学   331908篇
内科学   706414篇
皮肤病学   85485篇
神经病学   293516篇
特种医学   137416篇
外国民族医学   943篇
外科学   541115篇
综合类   77858篇
现状与发展   8篇
一般理论   1399篇
预防医学   277169篇
眼科学   84029篇
药学   264390篇
  12篇
中国医学   7997篇
肿瘤学   199779篇
  2019年   28808篇
  2018年   40995篇
  2017年   31253篇
  2016年   35574篇
  2015年   40303篇
  2014年   55747篇
  2013年   83320篇
  2012年   112332篇
  2011年   118923篇
  2010年   71216篇
  2009年   67601篇
  2008年   110684篇
  2007年   117881篇
  2006年   119474篇
  2005年   114602篇
  2004年   110307篇
  2003年   106053篇
  2002年   102476篇
  2001年   175950篇
  2000年   180080篇
  1999年   151451篇
  1998年   43095篇
  1997年   37961篇
  1996年   38061篇
  1995年   36930篇
  1994年   33736篇
  1993年   31627篇
  1992年   117256篇
  1991年   113089篇
  1990年   109480篇
  1989年   105755篇
  1988年   96697篇
  1987年   94722篇
  1986年   88950篇
  1985年   84908篇
  1984年   63327篇
  1983年   53750篇
  1982年   31545篇
  1981年   28130篇
  1979年   56022篇
  1978年   39348篇
  1977年   33469篇
  1976年   31209篇
  1975年   33036篇
  1974年   39426篇
  1973年   37667篇
  1972年   35165篇
  1971年   32648篇
  1970年   30167篇
  1969年   28828篇
排序方式: 共有10000条查询结果,搜索用时 234 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