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   4020966篇
  免费   291829篇
  国内免费   9061篇
耳鼻咽喉   55937篇
儿科学   131989篇
妇产科学   110783篇
基础医学   574777篇
口腔科学   112171篇
临床医学   371020篇
内科学   776310篇
皮肤病学   93034篇
神经病学   326668篇
特种医学   152303篇
外国民族医学   1143篇
外科学   601658篇
综合类   83866篇
现状与发展   15篇
一般理论   1609篇
预防医学   315451篇
眼科学   93863篇
药学   296859篇
  15篇
中国医学   7864篇
肿瘤学   214521篇
  2019年   32430篇
  2018年   44810篇
  2017年   33947篇
  2016年   39057篇
  2015年   43990篇
  2014年   61478篇
  2013年   93106篇
  2012年   125467篇
  2011年   133243篇
  2010年   80085篇
  2009年   76199篇
  2008年   124671篇
  2007年   132578篇
  2006年   134477篇
  2005年   129775篇
  2004年   124923篇
  2003年   120354篇
  2002年   116364篇
  2001年   183280篇
  2000年   188130篇
  1999年   159094篇
  1998年   47354篇
  1997年   41584篇
  1996年   41740篇
  1995年   40116篇
  1994年   36836篇
  1993年   34642篇
  1992年   124733篇
  1991年   120928篇
  1990年   117629篇
  1989年   114004篇
  1988年   104919篇
  1987年   102818篇
  1986年   96821篇
  1985年   92787篇
  1984年   69391篇
  1983年   59077篇
  1982年   35269篇
  1981年   31749篇
  1979年   62983篇
  1978年   44805篇
  1977年   37828篇
  1976年   35602篇
  1975年   38027篇
  1974年   45340篇
  1973年   43210篇
  1972年   40666篇
  1971年   38186篇
  1970年   35163篇
  1969年   33836篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
63.
G. Berlin  M. Hammar  L. Tapper 《Platelets》2019,30(4):473-479
Platelets are needed to prevent or arrest bleeding and aggregate at the site of injury upon vascular damage. Platelets express receptors for estrogens which might affect the function of the platelets and their hemostatic ability. The aim was to identify possible differences in platelet function related to age, gender, and phases of the menstrual cycle by use of impedance aggregometry with Multiplate. In the first part of the study, platelet function was assessed in 60 healthy individuals (30 men and 30 women) in each of three age groups (20–25, 40–45, and 60–65 years). In the second part of the study, the platelet function was analyzed on four occasions during the menstrual cycle in women without oral contraceptives (OCs) (n = 17) and compared to 19 women on OCs and 18 men of similar age (20–40 years). For the women on OCs, aggregation was analyzed once during the tablet-free week and once late during the period with OCs. The men were sampled once. Women of younger age (<45 years) had significantly higher agonist-induced aggregation response than both men and post-menopausal women (60–65 years). The agonist-induced aggregation response did not differ between phases of the menstrual cycle or OC use. The results suggest that estradiol and/or progesterone affect spontaneous aggregation since it was found to be lowest in the mid-luteal phase. Spontaneous aggregation was significantly lower in women on OCs than in both men and women without OCs. Our findings indicate that fertile age is associated with higher aggregation response capacity of the platelets, possibly to prevent excessive bleeding during menstruation, but this response capacity is not altered during the menstrual cycle or by use of OCs.  相似文献   
64.
65.
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   

66.
67.
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   
68.
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