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   2557053篇
  免费   199102篇
  国内免费   4167篇
耳鼻咽喉   36301篇
儿科学   85399篇
妇产科学   73962篇
基础医学   368559篇
口腔科学   74573篇
临床医学   223681篇
内科学   496147篇
皮肤病学   54631篇
神经病学   204155篇
特种医学   100962篇
外国民族医学   793篇
外科学   391103篇
综合类   59863篇
现状与发展   4篇
一般理论   809篇
预防医学   195775篇
眼科学   59649篇
药学   193983篇
  4篇
中国医学   4787篇
肿瘤学   135182篇
  2018年   23893篇
  2015年   23939篇
  2014年   33019篇
  2013年   50343篇
  2012年   68642篇
  2011年   73074篇
  2010年   43070篇
  2009年   40917篇
  2008年   70182篇
  2007年   74974篇
  2006年   76229篇
  2005年   74320篇
  2004年   72554篇
  2003年   69747篇
  2002年   68552篇
  2001年   115786篇
  2000年   119299篇
  1999年   101309篇
  1998年   28525篇
  1997年   25769篇
  1996年   25867篇
  1995年   24879篇
  1994年   23425篇
  1993年   21992篇
  1992年   83475篇
  1991年   81619篇
  1990年   80255篇
  1989年   77769篇
  1988年   72373篇
  1987年   71402篇
  1986年   67963篇
  1985年   65308篇
  1984年   49027篇
  1983年   42596篇
  1982年   25139篇
  1981年   22335篇
  1980年   21060篇
  1979年   47000篇
  1978年   32883篇
  1977年   28012篇
  1976年   26496篇
  1975年   28428篇
  1974年   34217篇
  1973年   33023篇
  1972年   30930篇
  1971年   28889篇
  1970年   26773篇
  1969年   25315篇
  1968年   23452篇
  1967年   21023篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
21.
22.
23.
24.
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   
25.
26.
27.
28.
29.
Academic output is just one aspect of a successful career as a plastic surgeon. However, for those with a strong interest in academia, the academic output of a department will likely be a key factor when deciding how to rank jobs. The aim of this study was to quantify and rank the academic output of plastic surgery units across the UK and Ireland. The Institute for Scientific Information (ISI) Web of Science Bibliometric analysis tool was used to collate cumulative (1950–2016), 10 year (2006–2016) and 3 years (2013–2015) research output data for plastic surgery units in the UK and Ireland. Sixty-six plastic surgery units were identified. Departments were ranked for each time period according to the number of papers produced, number of citations (Nc) and h-index (a measure of the impact of scientific output). The top 3 departments for number of papers in the last 10 years were The Royal Free Hospital, London (226) Broomfield Hospital, Chelmsford (218), and Morriston Hospital and Swansea (188). The top 3 for h-number were The Royal Free Hospital (21) Wythenshawe Hospital, Manchester (18) and Morriston Hospital (17). Academic output varies across plastic surgery units in the UK and Ireland. A number of departments have consistently maintained high academic outputs across the years and will be of interest to surgeons hoping to pursue a career in academia.  相似文献   
30.
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