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   12026篇
  免费   1218篇
  国内免费   21篇
耳鼻咽喉   220篇
儿科学   353篇
妇产科学   330篇
基础医学   1811篇
口腔科学   188篇
临床医学   1414篇
内科学   2131篇
皮肤病学   136篇
神经病学   1127篇
特种医学   359篇
外科学   1600篇
综合类   283篇
一般理论   19篇
预防医学   1379篇
眼科学   210篇
药学   863篇
中国医学   15篇
肿瘤学   827篇
  2022年   76篇
  2021年   211篇
  2020年   158篇
  2019年   237篇
  2018年   269篇
  2017年   194篇
  2016年   205篇
  2015年   265篇
  2014年   371篇
  2013年   494篇
  2012年   747篇
  2011年   714篇
  2010年   377篇
  2009年   311篇
  2008年   565篇
  2007年   593篇
  2006年   601篇
  2005年   583篇
  2004年   538篇
  2003年   533篇
  2002年   526篇
  2001年   359篇
  2000年   333篇
  1999年   303篇
  1998年   154篇
  1997年   93篇
  1996年   105篇
  1995年   94篇
  1994年   95篇
  1993年   96篇
  1992年   209篇
  1991年   221篇
  1990年   201篇
  1989年   203篇
  1988年   173篇
  1987年   190篇
  1986年   167篇
  1985年   178篇
  1984年   134篇
  1983年   102篇
  1982年   73篇
  1981年   64篇
  1980年   74篇
  1979年   87篇
  1978年   70篇
  1977年   69篇
  1975年   70篇
  1974年   66篇
  1973年   77篇
  1972年   68篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Patient navigation is a strategy for overcoming barriers to reduce disparities and to improve access and outcomes. The aim of this umbrella review was to identify, critically appraise, synthesize, and present the best available evidence to inform policy and planning regarding patient navigation across the cancer continuum. Systematic reviews examining navigation in cancer care were identified in the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Embase, Cumulative Index of Nursing and Allied Health (CINAHL), Epistemonikos, and Prospective Register of Systematic Reviews (PROSPERO) databases and in the gray literature from January 1, 2012, to April 19, 2022. Data were screened, extracted, and appraised independently by two authors. The JBI Critical Appraisal Checklist for Systematic Review and Research Syntheses was used for quality appraisal. Emerging literature up to May 25, 2022, was also explored to capture primary research published beyond the coverage of included systematic reviews. Of the 2062 unique records identified, 61 systematic reviews were included. Fifty-four reviews were quantitative or mixed-methods reviews, reporting on the effectiveness of cancer patient navigation, including 12 reviews reporting costs or cost-effectiveness outcomes. Seven qualitative reviews explored navigation needs, barriers, and experiences. In addition, 53 primary studies published since 2021 were included. Patient navigation is effective in improving participation in cancer screening and reducing the time from screening to diagnosis and from diagnosis to treatment initiation. Emerging evidence suggests that patient navigation improves quality of life and patient satisfaction with care in the survivorship phase and reduces hospital readmission in the active treatment and survivorship care phases. Palliative care data were extremely limited. Economic evaluations from the United States suggest the potential cost-effectiveness of navigation in screening programs.  相似文献   
2.
3.
4.
5.
6.
OBJECTIVE: To determine the age at which infants achieve velopharyngeal closure during vocalization. DESIGN: Longitudinal with repeated measures. SETTING: Laboratory. PARTICIPANTS: Six healthy infants were studied monthly from ages 2 to 6 months while they interacted with a parent and an investigator. MAIN OUTCOME MEASURES: The presence or absence of velopharyngeal closure, as determined by sensing ram pressure at the anterior nares. RESULTS: The velopharynx was open for windups, whimpers, and laughs, and it was closed for cries, screams, and raspberries, regardless of age. The frequency with which the velopharynx closed during syllable utterances increased significantly with age. CONCLUSIONS: Velopharyngeal closure for speech-like utterance increases with age, but is not complete and is still undergoing development at 6 months of age. Velopharyngeal closure during infancy may be influenced by pressure demands of the utterance; however, support for this speculation is stronger for other types of utterances than it is for speech-like utterances. The method used in this study holds promise for evaluating infants with suspected velopharyngeal impairment.  相似文献   
7.
Postpartum fatigue is a normal condition that most women experience. Breastfeeding is often associated in women's minds as contributing to the feeling of overall perceived fatigue, and many women indicate that they have ceased breastfeeding because of fatigue. However, the relationship between feeding choice and perceived fatigue has never been established. Two hundred and fifty-three women participated in a study examining whether perceived fatigue differed for bottle-feeding and breastfeeding women at 3 different times during the postpartum period (2-4 days, 6 weeks, and 12 weeks postpartum). Results showed no significant differences for these 2 groups, suggesting that perceived fatigue during the postpartum period is not dependent on feeding choice. Additional analyses examining other variables with a potential effect were nonsignificant. Because perceived physical fatigue does not appear to be dependent on feeding choice, women should be prepared for the feeling of perceived fatigue during the postpartum period while at the same time be reassured that feeding choice is not correlated.  相似文献   
8.
9.
Increase in Power through Multivariate Analyses   总被引:6,自引:0,他引:6  
Power to detect genetic and environmental influences increases not only with sample size but also with the number of measurements through longitudinal and/or multivariate designs, if those measurements correlate with each other. Power simulations are presented for uni- through quadrivariate cases, with differing genetic and environmental parameters. Even though subject attrition is a problem for most longitudinal studies, the gain in power available may more than make up for this shortcoming in many situations. In terms of planning studies to examine genetic and environmental influences, power calculations should not only consider sample size but number of measurements on particular phenotypes and their intercorrelations.  相似文献   
10.
A crossover double-blind controlled trial was performed on 36 patients with rheumatoid arthritis to assess the necessity for serum salicylate monitoring in determining optimal dosage. There was no clinically or statistically significant increase in the clinical improvement of patients associated with serum monitoring but potentially toxic serum levels occurred without tinnitus when serum monitoring was not used.  相似文献   
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