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   2555043篇
  免费   199051篇
  国内免费   4164篇
耳鼻咽喉   36306篇
儿科学   85350篇
妇产科学   73916篇
基础医学   368426篇
口腔科学   74549篇
临床医学   223440篇
内科学   495523篇
皮肤病学   54634篇
神经病学   204104篇
特种医学   100917篇
外国民族医学   793篇
外科学   390802篇
综合类   59813篇
现状与发展   4篇
一般理论   808篇
预防医学   195561篇
眼科学   59596篇
药学   193952篇
  3篇
中国医学   4782篇
肿瘤学   134979篇
  2018年   23897篇
  2015年   23933篇
  2014年   33006篇
  2013年   50352篇
  2012年   68627篇
  2011年   73055篇
  2010年   43066篇
  2009年   40908篇
  2008年   70182篇
  2007年   74954篇
  2006年   76216篇
  2005年   74316篇
  2004年   72536篇
  2003年   69725篇
  2002年   68562篇
  2001年   115791篇
  2000年   119283篇
  1999年   101308篇
  1998年   28520篇
  1997年   25765篇
  1996年   25851篇
  1995年   24870篇
  1994年   23417篇
  1993年   21990篇
  1992年   83455篇
  1991年   81602篇
  1990年   80238篇
  1989年   77753篇
  1988年   72368篇
  1987年   71383篇
  1986年   67947篇
  1985年   65284篇
  1984年   49020篇
  1983年   42583篇
  1982年   25127篇
  1981年   22322篇
  1980年   21041篇
  1979年   46981篇
  1978年   32870篇
  1977年   28005篇
  1976年   26486篇
  1975年   28424篇
  1974年   34212篇
  1973年   33014篇
  1972年   30913篇
  1971年   28874篇
  1970年   26756篇
  1969年   25306篇
  1968年   23450篇
  1967年   21020篇
排序方式: 共有10000条查询结果,搜索用时 671 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