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   3611832篇
  免费   261762篇
  国内免费   9459篇
耳鼻咽喉   48816篇
儿科学   119962篇
妇产科学   99381篇
基础医学   508304篇
口腔科学   102112篇
临床医学   331291篇
内科学   705231篇
皮肤病学   85364篇
神经病学   292744篇
特种医学   137206篇
外国民族医学   941篇
外科学   540218篇
综合类   77802篇
现状与发展   8篇
一般理论   1393篇
预防医学   277042篇
眼科学   83856篇
药学   264068篇
  12篇
中国医学   7987篇
肿瘤学   199315篇
  2019年   28671篇
  2018年   40860篇
  2017年   31141篇
  2016年   35442篇
  2015年   40145篇
  2014年   55568篇
  2013年   83049篇
  2012年   111935篇
  2011年   118471篇
  2010年   70946篇
  2009年   67350篇
  2008年   110322篇
  2007年   117436篇
  2006年   119041篇
  2005年   114198篇
  2004年   109885篇
  2003年   105690篇
  2002年   102078篇
  2001年   175765篇
  2000年   179896篇
  1999年   151288篇
  1998年   42995篇
  1997年   37870篇
  1996年   38001篇
  1995年   36844篇
  1994年   33682篇
  1993年   31566篇
  1992年   117095篇
  1991年   112941篇
  1990年   109316篇
  1989年   105615篇
  1988年   96577篇
  1987年   94593篇
  1986年   88804篇
  1985年   84790篇
  1984年   63208篇
  1983年   53635篇
  1982年   31459篇
  1981年   28045篇
  1979年   55922篇
  1978年   39257篇
  1977年   33404篇
  1976年   31144篇
  1975年   32959篇
  1974年   39320篇
  1973年   37579篇
  1972年   35095篇
  1971年   32577篇
  1970年   30104篇
  1969年   28778篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
51.
52.
53.
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   
54.
55.
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   

56.
57.
58.
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   
59.
60.
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