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   2583770篇
  免费   189286篇
  国内免费   7564篇
耳鼻咽喉   34284篇
儿科学   85217篇
妇产科学   71574篇
基础医学   363668篇
口腔科学   69703篇
临床医学   234539篇
内科学   515596篇
皮肤病学   62508篇
神经病学   213505篇
特种医学   99883篇
外国民族医学   736篇
外科学   386488篇
综合类   50394篇
现状与发展   5篇
一般理论   968篇
预防医学   196183篇
眼科学   56680篇
药学   188090篇
  8篇
中国医学   5331篇
肿瘤学   145260篇
  2021年   19994篇
  2019年   20634篇
  2018年   29306篇
  2017年   22612篇
  2016年   26245篇
  2015年   29525篇
  2014年   40460篇
  2013年   60448篇
  2012年   80248篇
  2011年   84525篇
  2010年   51016篇
  2009年   49162篇
  2008年   79058篇
  2007年   83867篇
  2006年   85602篇
  2005年   81757篇
  2004年   78739篇
  2003年   76061篇
  2002年   73356篇
  2001年   128413篇
  2000年   131343篇
  1999年   110513篇
  1998年   31255篇
  1997年   27926篇
  1996年   28219篇
  1995年   27383篇
  1994年   25071篇
  1993年   23423篇
  1992年   85179篇
  1991年   81576篇
  1990年   78804篇
  1989年   76080篇
  1988年   69481篇
  1987年   68000篇
  1986年   63555篇
  1985年   60525篇
  1984年   44953篇
  1983年   37950篇
  1982年   22456篇
  1981年   19994篇
  1979年   38961篇
  1978年   27439篇
  1977年   23254篇
  1976年   21499篇
  1975年   22814篇
  1974年   26786篇
  1973年   25371篇
  1972年   23749篇
  1971年   21955篇
  1970年   20184篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
Introduction: Pharmacovigilance is essential to monitoring the safety profiles of authorized medicines. Compared with small-molecule drugs, biological drugs are more complex, more susceptible to structural variability due to manufacturing processes, and have the potential to induce immune-related reactions, underscoring the importance of safety monitoring for these products. Although highly similar to reference products, biosimilars are not expected to be structurally identical. For these reasons, proper reporting of potential adverse drug reactions (ADRs) using distinguishable names and batch numbers is essential for accurate tracing of all biological drugs. To address the need for robust pharmacovigilance, the European Parliament and Council of the European Union provided legislation regarding pharmacovigilance of biologics in 2010.

Areas covered: This narrative review examines the current state of pharmacovigilance for biologics in the European Union (EU) and discusses relevant information on pharmacovigilance of biosimilars, the current EU pharmacovigilance system, and areas that could be improved.

Expert opinion: Although steps have been taken to improve pharmacovigilance of biologics in the EU, several enhancements can still be made, including additional training for healthcare professionals on ADR reporting, the use of 2D barcodes that enhance traceability, and an open discussion of potentially missed opportunities in the pharmacovigilance of biosimilars.  相似文献   

43.
44.
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   
45.
46.
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   

47.
48.
49.
50.
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