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   102391篇
  免费   29001篇
  国内免费   1115篇
耳鼻咽喉   2431篇
儿科学   2701篇
妇产科学   2370篇
基础医学   3001篇
口腔科学   5177篇
临床医学   26206篇
内科学   25751篇
皮肤病学   3330篇
神经病学   12702篇
特种医学   3759篇
外科学   18839篇
综合类   117篇
现状与发展   40篇
一般理论   1篇
预防医学   13366篇
眼科学   2139篇
药学   1503篇
中国医学   30篇
肿瘤学   9044篇
  2024年   747篇
  2023年   5057篇
  2022年   1231篇
  2021年   2867篇
  2020年   5392篇
  2019年   2124篇
  2018年   7017篇
  2017年   7415篇
  2016年   8011篇
  2015年   8101篇
  2014年   10560篇
  2013年   12305篇
  2012年   4009篇
  2011年   3734篇
  2010年   6926篇
  2009年   9235篇
  2008年   3681篇
  2007年   2640篇
  2006年   3815篇
  2005年   2326篇
  2004年   1713篇
  2003年   1361篇
  2002年   1235篇
  2001年   1926篇
  2000年   1258篇
  1999年   1760篇
  1998年   2121篇
  1997年   1930篇
  1996年   1983篇
  1995年   1713篇
  1994年   1116篇
  1993年   922篇
  1992年   772篇
  1991年   673篇
  1990年   549篇
  1989年   559篇
  1988年   536篇
  1987年   415篇
  1986年   373篇
  1985年   317篇
  1984年   273篇
  1983年   324篇
  1982年   233篇
  1981年   202篇
  1980年   130篇
  1978年   130篇
  1977年   127篇
  1976年   97篇
  1974年   84篇
  1972年   82篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
111.
112.
113.
114.
Milos Jesenak  MD  PhD    Peter Banovcin  MD  PhD    Zuzana Rennerova  MD  PhD    Lubica Jakusova  MD  PhD    Zuzana Havlicekova  MD  PhD    Vladimir Pohanka  MD  PhD  MPH  FCCP    Maria Pia Villa  MD  PhD    Roberto Ronchetti  MD  PhD 《International journal of dermatology》2009,48(9):941-946
Background  The atopy patch test (APT) is no longer an experimental method; it is increasingly being used as a standard diagnostic tool for the characterization of patients with aeroallergen- and food-triggered disorders. Some technical aspects of this test still remain to be answered. We aimed to study the reproducibility of this test over time in the general child population.
Methods  In a general population of 118 children, we investigated the reproducibility of duplicate APTs with four food allergens in their native form, which were repeated at set intervals from the first test: 7 days (group 1), 14 days (group 2), and 21 days (group 3).
Results  We observed very poor reproducibility on both sides of the back in all three studied subgroups. The reproducibility rates and Cohen's κ values did not improve when we did not consider the side of the back. There were no differences in the prevalence of atopy between the subjects with reproducible and nonreproducible APT results. All three groups studied showed no difference in the prevalence rates of atopy. There was no relationship between APT and skin prick test positivity for the same allergen. Questionnaire-derived data about previous food-related reactions did not help in the evaluation of the doubtful nonreproducible APT results with food allergens.
Conclusions  Our results show that the reproducibility of food APTs is poor and unsatisfactory over time, and there is an urgent need for the development of optimal, stable, and good-quality APT testing substances.  相似文献   
115.
Iron deficiency may exacerbate symptoms in the Restless Legs Syndrome (RLS). We investigated the effect of intravenous iron sucrose or placebo on symptoms in patients with RLS and mild to moderate iron deficit. Sixty patients with primary RLS (seven males, age 46 (9) years, S‐ferritin ≤45 μg/L) recruited from a cohort of 231 patients were randomly assigned in a 12‐months double‐blind, multi‐centre study of iron sucrose 1000 mg (n = 29) or saline (n = 31). The primary efficacy variable was the RLS severity scale (IRLS) score at week 11. Median IRLS score decreased from 24 to 7 (week 11) after iron sucrose and from 26 to 17 after placebo (P = 0.123, N.S. for between treatment comparison). The corresponding scores at week 7 were 12 and 20 in the two groups (P = 0.017). Drop out rate because of lack of efficacy at 12 months was 19/31 after placebo and 5/29 patients after iron sucrose (Kaplan–Meier estimate, log rank test P = 0.0006) suggesting an iron induced superior long term RLS symptom control. Iron sucrose was well tolerated. This study showed a lack of superiority of iron sucrose at 11 weeks but found evidence that iron sucrose reduced RLS symptoms both in the acute phase (7 weeks) and during long‐term follow up in patients with variable degree of iron deficiency. Further studies on target patient groups, dosing and dosing intervals are warranted before iron sucrose could be considered for treatment of iron deficient patients with RLS. © 2009 Movement Disorder Society  相似文献   
116.
117.
This study evaluated the effects of tobacco Purchase, Use and Possession (PUP) laws on student perceptions of adolescent tobacco use within towns and schools. Twenty‐four towns were randomly assigned into two conditions, the experimental condition (E PUP) involved efforts to increase both PUP law enforcement and reduce minors' access to commercial sources of tobacco, whereas the control condition (C) focused only on efforts to reduce minors' access to commercial sources of tobacco. A hierarchical linear modeling analytical approach was selected due to the multilevel data and nested design. The present study found that over time, youth in the experimental PUP condition observed less youth tobacco usage at school and in their town, and perceived lower rates of tobacco among their peers at school and among friends than youth in the control condition. The findings suggest that PUP law enforcement might be used to strengthen community norms against youth tobacco use.  相似文献   
118.
119.
120.
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