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   4010907篇
  免费   290931篇
  国内免费   9037篇
耳鼻咽喉   55847篇
儿科学   131647篇
妇产科学   110602篇
基础医学   573368篇
口腔科学   111996篇
临床医学   369718篇
内科学   774556篇
皮肤病学   92899篇
神经病学   325620篇
特种医学   152066篇
外国民族医学   1141篇
外科学   600433篇
综合类   83605篇
现状与发展   15篇
一般理论   1602篇
预防医学   314191篇
眼科学   93582篇
药学   296077篇
  15篇
中国医学   7856篇
肿瘤学   214039篇
  2019年   32274篇
  2018年   44631篇
  2017年   33830篇
  2016年   38900篇
  2015年   43810篇
  2014年   61197篇
  2013年   92673篇
  2012年   124889篇
  2011年   132605篇
  2010年   79758篇
  2009年   75849篇
  2008年   124129篇
  2007年   131965篇
  2006年   133888篇
  2005年   129211篇
  2004年   124326篇
  2003年   119829篇
  2002年   115887篇
  2001年   183124篇
  2000年   187968篇
  1999年   158929篇
  1998年   47192篇
  1997年   41477篇
  1996年   41629篇
  1995年   40015篇
  1994年   36754篇
  1993年   34579篇
  1992年   124636篇
  1991年   120819篇
  1990年   117508篇
  1989年   113897篇
  1988年   104813篇
  1987年   102721篇
  1986年   96717篇
  1985年   92693篇
  1984年   69297篇
  1983年   59000篇
  1982年   35177篇
  1981年   31678篇
  1979年   62890篇
  1978年   44721篇
  1977年   37762篇
  1976年   35545篇
  1975年   37965篇
  1974年   45282篇
  1973年   43145篇
  1972年   40606篇
  1971年   38141篇
  1970年   35117篇
  1969年   33798篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
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   
63.
64.
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   

65.
66.
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   
67.
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