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   844篇
  免费   53篇
  国内免费   6篇
耳鼻咽喉   6篇
儿科学   13篇
妇产科学   7篇
基础医学   110篇
口腔科学   1篇
临床医学   68篇
内科学   224篇
皮肤病学   5篇
神经病学   56篇
特种医学   15篇
外科学   75篇
综合类   14篇
预防医学   99篇
眼科学   1篇
药学   24篇
中国医学   3篇
肿瘤学   182篇
  2022年   9篇
  2021年   20篇
  2020年   12篇
  2019年   12篇
  2018年   13篇
  2017年   14篇
  2016年   20篇
  2015年   21篇
  2014年   45篇
  2013年   43篇
  2012年   61篇
  2011年   59篇
  2010年   31篇
  2009年   36篇
  2008年   50篇
  2007年   52篇
  2006年   28篇
  2005年   45篇
  2004年   26篇
  2003年   32篇
  2002年   21篇
  2001年   31篇
  2000年   23篇
  1999年   31篇
  1998年   9篇
  1997年   6篇
  1996年   5篇
  1995年   8篇
  1994年   5篇
  1993年   6篇
  1992年   13篇
  1991年   7篇
  1990年   14篇
  1989年   10篇
  1988年   7篇
  1987年   4篇
  1986年   4篇
  1985年   5篇
  1984年   7篇
  1982年   3篇
  1981年   4篇
  1979年   5篇
  1977年   3篇
  1972年   2篇
  1970年   3篇
  1969年   3篇
  1962年   2篇
  1925年   2篇
  1923年   3篇
  1921年   2篇
排序方式: 共有903条查询结果,搜索用时 15 毫秒
1.
2.
The growth and maturity status of 201 elite female gymnasts was considered. The subjects were participants at the 24 World Championship Artistic Gymnastics in 1987. In addition to age at menarche, weight, stature, biacromial, and bicristal breadths, the sitting height/stature ratio, and the Health-Carter anthropometric somatotype of gymnasts 13-20 yr of age were compared with reference data for a nationally representative sample of Flemish girls. Median age at menarche (probit analysis) in gymnasts is 15.6 +/- 2.1 yr compared with 13.2 +/- 1.2 yr in Flemish girls. Anthropometric dimensions increase with age until about 16 yr and then tend to plateau. In contrast to body size, there is little variation in somatotype with age. Compared with adolescent girls, elite gymnasts are considerably shorter and lighter with narrower shoulders and hips, but the differences are more apparent after 17 yr. Elite gymnasts do not differ from nonathletes in relative leg length, but they have proportionally broader shoulders relative to hips. Differences in somatotype occur primarily in endomorphy (especially lower in gymnasts) and to a lesser extent in mesomorphy (higher in gymnasts).  相似文献   
3.
4.
A plasma PCR test, using a nonradioactive PCR plate assay, was evaluated for detection of human cytomegalovirus reactivation. This assay was compared to Southern blotting and found to perform well. As a noncompetitive method of quantitation, it was similar to a competitive method for detecting the number of genome copies per milliliter of plasma in marrow transplant recipients. This is a technically simplified assay with potential for adaptation to automation.  相似文献   
5.
6.
7.
OBJECTIVE: To study the association between plasma antioxidants (beta-carotene and alpha-tocopherol) and lung function in Dutch adults aged 20-59 y. DESIGN: Cross-sectional. SETTING: Population-based study. Subjects: A random sample (n=367) was drawn from all participants (men and women) aged 20-59 y with reproducible lung function measurements in 1995. INTERVENTION: Completion of general questionnaire and physical examination. MAIN OUTCOME MEASUREMENTS: Forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and plasma levels of beta-carotene and alpha-tocopherol. RESULTS: Subjects with a high plasma beta-carotene level (90th percentile, that is 0.57 micromol/L) tended to have a higher FEV1 (73 ml, s.e.m. 60 ml; P=0.22) and a higher FVC (147 ml, s.e.m. 76 ml; P=0.05) than subjects with a low plasma beta-carotene level (10th percentile, that is 0.11 micromol/L) after adjustment for age, height, gender, smoking status, pack-years of smoking and alcohol consumption. There was no difference in lung function between subjects with high and low plasma alpha-tocopherol concentrations. CONCLUSIONS: The results suggest that subjects with a high plasma beta-carotene tended to have a higher FVC than subjects with a low plasma beta-carotene concentration which was borderline statistically significant. The difference for FEV1 between high and low levels of plasma beta-carotene tended to be in the same positive direction as that of FVC but did not reach the pre-set statistical significance level. There is no relation between plasma alpha-tocopherol and lung function. SPONSORSHIP: Ministry of Public Health, Welfare and Sports of the Netherlands and the National Institute of Public Health and the Environment.  相似文献   
8.
9.
Research on dietary intake and its determinants is crucial for an adequate response to the current epidemic of diet‐related non‐communicable chronic diseases. In order to respond to this challenge, the RICHFIELDS project was tasked with designing a research infrastructure (RI) that connects data on dietary intake of consumers in Europe, and its determinants, collected using apps and wearable sensors, from behavioural laboratories and experimental facilities and from other RIs. The main output of the project, an RI design, describes interfaces (portals) to collect data, a meta‐database and a data‐model to enable data linkage and sharing. The RICHFIELDS project comprises three phases, each consisting of three work packages, and an overarching methodological support work package. Phase 1 focused on data generated by consumers (e.g. collected by apps and sensors) relating to the purchase, preparation and consumption of food. Phase 2 focused on data generated by organisations such as businesses (e.g. retail data), government (e.g. procurement data) and experimental research facilities (e.g. virtual supermarkets). Phases 1 and 2 provided Phase 3 with insights on data types and design requirements, including the business models, data integration and management systems and governance and ethics. The final design will be used in the coming years to build an RI for the scientific research community, policy makers and businesses in Europe. The RI will boost interdisciplinary multi‐stakeholder research through harmonisation and integration of data on food behaviour.  相似文献   
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