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   12702篇
  免费   975篇
  国内免费   24篇
耳鼻咽喉   70篇
儿科学   539篇
妇产科学   289篇
基础医学   1667篇
口腔科学   112篇
临床医学   2114篇
内科学   2281篇
皮肤病学   125篇
神经病学   1220篇
特种医学   239篇
外科学   1083篇
综合类   135篇
一般理论   29篇
预防医学   1644篇
眼科学   222篇
药学   845篇
中国医学   21篇
肿瘤学   1066篇
  2023年   143篇
  2022年   190篇
  2021年   327篇
  2020年   268篇
  2019年   389篇
  2018年   378篇
  2017年   307篇
  2016年   327篇
  2015年   337篇
  2014年   437篇
  2013年   682篇
  2012年   1028篇
  2011年   1000篇
  2010年   527篇
  2009年   467篇
  2008年   851篇
  2007年   844篇
  2006年   828篇
  2005年   760篇
  2004年   701篇
  2003年   617篇
  2002年   628篇
  2001年   96篇
  2000年   63篇
  1999年   121篇
  1998年   130篇
  1997年   100篇
  1996年   107篇
  1995年   99篇
  1994年   70篇
  1993年   66篇
  1992年   52篇
  1991年   60篇
  1990年   46篇
  1989年   36篇
  1988年   46篇
  1987年   43篇
  1986年   32篇
  1985年   32篇
  1984年   33篇
  1983年   36篇
  1982年   37篇
  1981年   37篇
  1980年   38篇
  1979年   23篇
  1978年   25篇
  1976年   17篇
  1975年   25篇
  1974年   23篇
  1973年   26篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
Although studies have documented underuse of controller medications and overuse of short-acting inhaled ss(2)-agonist among children with persistent asthma in disadvantaged communities, the persistence of oral ss(2)-agonist use in pediatric practice has not been studied since inhaled short-acting ss(2)-agonists became widespread. We describe medications used to treat asthma among children 3 to 5 years of age at 10 Head Start and other subsidized preschool centers in East and Central Harlem, New York City. We interviewed 149 parents/guardians of children who were identified as having probable asthma based on physician's diagnosis, persistent symptoms, hospitalization, and medication use. We classified 86 of the 149 children (58%) as having current persistent asthma. Only 15 of them (17%) were reported to have used controller medications at least 5 days/week in the last 4 weeks-only 2 of whom used inhaled corticosteroids. By contrast, 53 children (62%) used oral ss(2)-agonist in the last 4 weeks, often (72%) in conjunction with nebulized or inhaled short-acting ss(2)-agonist. Use of oral ss(2)-agonist was associated with more severe symptoms. This study documents the continued widespread use of oral ss(2)-agonist for treatment of children in a low-income community with high prevalence of asthma.  相似文献   
2.
BACKGROUND: Cardiac rehabilitation (CR) has an evidence base but traditional models may not readily apply to people living in rural and remote regions. AIM:: To outline published comprehensive and non-hospital based CR models used for people discharged from hospital after a cardiac event that have potential relevance to those living in rural and remote areas in Australia. METHODS: The PubMed database was searched using Medical subject headings (MeSH) terms and the key word 'cardiac rehabilitation' limited to clinical trials. Articles were retrieved if they included at least two components of CR and were not based in an outpatient setting. RESULTS: No CR models specifically developed for rural and remote areas were identified. However, 14 studies were found that outlined 11 non-conventional comprehensive CR models. All provided CR in a home-based setting. Health professionals provided support via telephone contact or home visits, and via resources such as the Heart Manual. Reported outcomes from these CR programs varied: ranging from an increase in knowledge of risk factors, to improvements in physical activity, decreased risk factor profile, improved psychological and social functioning and reductions in health service costs and mortality. CONCLUSION: Home-based, CR models have the most substantive evidence base and, therefore the greatest potential to be developed and made accessible to eligible people living in rural and remote areas.  相似文献   
3.
This study compared the predictive value of the theory of planned behavior in university students in South Africa (N = 251) and the United States (N = 160) who completed an anonymous self-administered questionnaire. Multiple regression analyses revealed that condom use and intention were significantly predicted by positive condom attitude, subjective norm, self-efficacy, and attending university in South Africa. Significant interactions between country and predictors indicated that subjective norm predicted condom use and intention more strongly in the American sample than in the South African sample; attitude predicted intention more strongly in the American sample than in the South African sample; but self-efficacy predicted intention more strongly in the South African sample than in the American sample. The theory of planned behavior may provide a useful framework for interventions to reduce South African students' risk of HIV/and sexuality transmitted diseases. Such interventions should especially focus on building self-efficacy to use condoms.  相似文献   
4.
Greater body fatness during childhood is associated with reduced risk of premenopausal breast cancer, but few studies have addressed the relation of adiposity with sex hormones in girls. We prospectively examined associations between adiposity and circulating levels of sex hormones and sex hormone-binding globulin (SHBG) among 286 girls in the Dietary Intervention Study in Children. Participants were 8 to 10 years old at baseline and were followed for an average of 7 years. Anthropometric measurements were taken at baseline and at subsequent annual visits, and blood samples were collected every 2 years. Concentrations of dehydroepiandrosterone sulfate (DHEAS) during follow-up were higher among girls with greater body mass index (BMI) at baseline. The mean for the lowest BMI quartile was 63.0 microg/dL compared with 78.8 microg/dL for the highest quartile, and each kg/m(2) increment in baseline BMI was associated with a 4.3% increase (95% confidence interval, 1.6-7.0%) in DHEAS levels during follow-up (P(trend) = 0.002). Concentrations of SHBG during follow-up were lower among girls with greater BMI at baseline. The mean for the lowest BMI quartile was 94.8 nmol compared with 57.5 nmol for the highest quartile, and each kg/m(2) increment in baseline BMI was associated with an 8.8% decrease (95% confidence interval, 7.0-10.6%) in SHBG levels during follow-up (P(trend) < 0.0001). Estrogen and progesterone concentrations were similar across BMI quartiles. These findings suggest that adiposity may alter DHEAS and SHBG levels in girls. Whether and how these differences affect breast development and carcinogenesis requires further research.  相似文献   
5.
6.
7.
8.
9.
10.
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