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   48364篇
  免费   3513篇
  国内免费   191篇
耳鼻咽喉   379篇
儿科学   1583篇
妇产科学   1252篇
基础医学   6887篇
口腔科学   602篇
临床医学   5150篇
内科学   10230篇
皮肤病学   919篇
神经病学   5623篇
特种医学   1172篇
外科学   4389篇
综合类   388篇
一般理论   59篇
预防医学   5746篇
眼科学   651篇
药学   3087篇
中国医学   88篇
肿瘤学   3863篇
  2024年   59篇
  2023年   654篇
  2022年   1092篇
  2021年   2183篇
  2020年   1319篇
  2019年   1823篇
  2018年   2084篇
  2017年   1396篇
  2016年   1550篇
  2015年   1693篇
  2014年   2061篇
  2013年   2687篇
  2012年   4292篇
  2011年   4245篇
  2010年   2160篇
  2009年   1879篇
  2008年   3012篇
  2007年   3000篇
  2006年   2847篇
  2005年   2638篇
  2004年   2353篇
  2003年   2109篇
  2002年   1798篇
  2001年   263篇
  2000年   241篇
  1999年   273篇
  1998年   363篇
  1997年   280篇
  1996年   232篇
  1995年   186篇
  1994年   140篇
  1993年   129篇
  1992年   110篇
  1991年   92篇
  1990年   85篇
  1989年   71篇
  1988年   71篇
  1987年   62篇
  1986年   65篇
  1985年   56篇
  1984年   63篇
  1983年   53篇
  1982年   39篇
  1981年   44篇
  1980年   31篇
  1979年   31篇
  1978年   19篇
  1977年   26篇
  1975年   15篇
  1973年   20篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Background.This study prospectively examined rates of adherence to mammography, clinical breast examination (CBE), and breast self-examination (BSE) in a cohort of women over 3 years to determine whether participation in BSE influenced participation in the other two screening modalities.Methods.Women ages 51 and older (n= 450) who attended a small group educational session to learn BSE and to hear about CBE and mammography guidelines were assessed annually by telephone for 3 consecutive years to determine their subsequent breast cancer screening behavior.Results.Annual CBE and mammography screening are highly positively associated. Regular performance of BSE has a modest positive association with both CBE and mammography adherence over time.Conclusions.Women who perform BSE regularly over time may be more likely to adhere to the other breast cancer screening guidelines.  相似文献   
72.
The portrayal of alcohol was examined in a systematic sampleof 50 programmes broadcast on British television. Four out offive programmes contained visual or verbal references to alcohol.On average, there was a reference to alcohol in every 6 minutesof programming. The programmes showed more alcohol being consumedthan soft drinks or beverages, but there were few referencesto the hazards of alcohol consumption. The main recommendationis that television companies should accept a responsibilityfor presenting a more realistic and healthier approach to theuse of alcohol in Britain  相似文献   
73.
Reprinted from Sexuality Update, a publication of The National Task Force On Sexuality and Disability of the American Congress of Rehabilitation Medicine, Vol 2, No. 1, 1989.  相似文献   
74.
75.
76.
Although the relationship of psychosocial factors to physical activity has been explored, there is increased interest in how perceptions of the community environment influence behavior. However, few methodological studies have incorporated perceptions of the social and community environment (protective social factors) or addressed key measurement issues. Computer-assisted telephone interviews were administered to a national sample of 1,818 U.S. adults. Unadjusted and multivariate-adjusted odds ratios were calculated to compare active and inactive participants by Protective Social Factors (PSF) scores and selected sociodemographics. Confirmatory factor analysis and reliability analysis suggested strong PSF scale psychometric properties (alpha = .92). After adjustment for potential confounders, a 10-point rise in the PSF score resulted in a 12% increased likelihood of meeting Centers for Disease Control and Prevention/American College of Sports Medicine recommendations. Additional analyses indicated that greater perceived PSFs were associated with meeting these recommendations among Whites but not among African Americans.  相似文献   
77.
Back pain among nurses is a common problem. Prior studies of this problem have been based on cross-sectional or retrospective data. This 18-month prospective study involving nurses newly graduated from nursing school investigated personal, worksite, and training factors associated with future risk of back pain. Each nurse underwent a preliminary interview and periodic follow-ups to identify those with back injuries. Contingency tables and logistic regression analyses demonstrated that prior significant back pain episodes (evidenced by previous job changes because of back pain, frequent medication use, etc.) were associated with increased future risk. Training at nursing school or on the job did not have a protective effect. This pilot study therefore suggests factors useful in placement and counseling of new nurses and indicates the need for further implementation of mechanical lift assist device use. © 1994 Wiley-Liss, Inc.  相似文献   
78.
The pathways and mechanisms of genomic change that have led to the peculiar haemoglobinless phenotype of the white-blooded Antarctic icefishes (16 species in the family Channichthyidae) constitute an important model for understanding the rapid diversification of the Antarctic notothenioid fish flock. To provide complementary structural information on genomic change at globin-gene loci in Antarctic fish species, cytogenetic studies and in-situ chromosomal mapping have been undertaken. Using a DNA probe containing one α- and one β-globin gene from the embryonic/juvenile globin gene cluster of the red-blooded species Notothenia coriiceps, we mapped the cluster on the chromosomes of Antarctic teleosts by fluorescence in-situ hybridization. As anticipated on the basis of its molecular organization, the cluster was located on a single chromosome pair in all of the red-blooded fish species probed (N. coriiceps, N. angustata, Trematomus hansoni, T. pennellii). In contrast, the α/β-globin probe did not recognize complementary sequences on the chromosomes of the white-blooded species Chionodraco hamatus and Channichthys rhinoceratus. These results represent the first example of chromosomal mapping of embryonic/juvenile globin genes in teleostean fishes. Beyond its relevance to the evolutionary history of Antarctic notothenioids, this work contributes to our understanding of the evolution of the chromosomal loci of globin genes in fishes and other vertebrates. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
79.
In an Italian hospital, we observed that hand hygiene was performed in 638 (19.6%) of 3,253 opportunities, whereas gloves were worn in 538 (44.2%) 1,218 of opportunities. We observed an inverse correlation between the intensity of care and the rate of hand hygiene compliance (R2=0.057; P<.001), but no such association was observed for the rate of glove use compliance (R2=0.014; P=.078). Rates of compliance with hand hygiene and glove use recommendations follow different behavioral patterns.  相似文献   
80.
INTRODUCTION: Very little is known about clinical nurse specialists and nurse practitioners (advance practice nurses [APNs]) who practice in emergency care settings. The Advanced Practice Committee of the ENA sought to determine a profile of these individuals. METHODS: Surveys were distributed to all registrants at 2 ENA conferences and posted on the ENA Web site. This survey asked 17 questions concerning the demographic characteristics of the APN respondents (eg, education, experience, certification, state recognition, and practice area). The survey was completed by 166 APNs. RESULTS: APNs had considerable experience as ED registered nurses before becoming an APN. They obtained their APN education at the master's degree or post-master's degree level. State recognition was required for 89.2% of the APNs. The majority of APNs (61.4%) obtained their certification through the American Nurses Credentialing Center. Nurse practitioners were predominantly family nurse practitioners (43%), and clinical nurse specialists were either critical care clinical nurse specialists (8.9%) or had other certifications (5.9%). APNs provided services in both the main emergency department and the fast track (45.7%) and were relatively new to their role as an APN. DISCUSSION: Consistent with current educational and certification requirements, the vast majority of APNs held a master's degree. Although relatively new to their role as APNs in emergency care, they were nonetheless very experienced as ED registered nurses. The majority of APNs were certified, even though that is not required for practice in all states. Continued research is needed to identify the most effective utilization of APNs, document their contributions to patient care outcomes, and develop strategies to meet their educational and practice needs.  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