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   20221篇
  免费   1455篇
  国内免费   38篇
耳鼻咽喉   178篇
儿科学   733篇
妇产科学   619篇
基础医学   2657篇
口腔科学   215篇
临床医学   2595篇
内科学   3586篇
皮肤病学   310篇
神经病学   2321篇
特种医学   396篇
外科学   1919篇
综合类   191篇
现状与发展   1篇
一般理论   22篇
预防医学   2885篇
眼科学   194篇
药学   1313篇
  1篇
中国医学   15篇
肿瘤学   1563篇
  2024年   36篇
  2023年   235篇
  2022年   364篇
  2021年   803篇
  2020年   497篇
  2019年   704篇
  2018年   783篇
  2017年   581篇
  2016年   666篇
  2015年   665篇
  2014年   816篇
  2013年   1257篇
  2012年   1770篇
  2011年   1766篇
  2010年   876篇
  2009年   770篇
  2008年   1200篇
  2007年   1301篇
  2006年   1135篇
  2005年   1048篇
  2004年   987篇
  2003年   818篇
  2002年   795篇
  2001年   136篇
  2000年   116篇
  1999年   137篇
  1998年   150篇
  1997年   120篇
  1996年   87篇
  1995年   81篇
  1994年   59篇
  1993年   58篇
  1992年   78篇
  1991年   54篇
  1990年   46篇
  1989年   54篇
  1988年   57篇
  1987年   56篇
  1986年   49篇
  1985年   41篇
  1984年   50篇
  1983年   29篇
  1982年   45篇
  1981年   46篇
  1980年   29篇
  1979年   30篇
  1978年   21篇
  1977年   17篇
  1976年   17篇
  1975年   33篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
The current study presents both longitudinal behavioral data and functional activation data documenting the effects of early focal brain injury on the development of spatial analytic processing in two children, one with prenatal left hemisphere (LH) injury and one with right hemisphere (RH) injury. A substantial body of evidence has shown that adults and children with early, lateralized brain injury show evidence of spatial analytic deficits. LH injury compromises the ability to encode the parts of a spatial pattern, while RH injury impairs pattern integration. The two children described in this report show patterns of deficit consistent with the site of their injury. In the current study, their longitudinal behavioral data spanning the age range from preschool to adolescence are presented in conjunction with data from a functional magnetic resonance imaging (fMRI) study of spatial processing. The activation results provide evidence that alternative profiles of neural organization can arise following early focal brain injury, and document where in the brain spatial functions are carried out when regions that normally mediate them are damaged. In addition, the coupling of the activation with the behavioral data allows us to go beyond the simple mapping of functional sites, to ask questions about how those sites may have come to mediate the spatial functions.  相似文献   
62.
In a survey of 5657 community-residing adolescents, those who said they could get a handgun in two days reported similar and those who said they could not get a handgun reported fewer risk behaviors and less violence perpetration and victimization than adolescents who have their own handgun. Adolescents who said they could get a handgun reported more exposure to and experience with firearms than those who said they could not get a handgun. Risk reduction efforts regarding adolescents should be expanded to include adolescents who say they can get a handgun.  相似文献   
63.
Effective programs set ambitious goals, achieve results, are managed well, and improve efficiency. Assessing performance, managing results, and assuring effective use of tax dollars is challenging and complex. This column describes how the federal government uses the Performance Assessment Rating Tool (PART) to ensure that its programs perform well and use public resources responsibly, and includes summaries of the performance assessments of three federally funded addiction treatment programs. An understanding of this process may help local addiction treatment programs implement similar strategies to improve their own performance, and thus contribute in a more meaningful way to improved outcomes for populations being treated for addictive disorders.  相似文献   
64.
65.
Following an abdominal hysterectomy and bilateral salpingoophorectomy wherein a superficial (1.6 mm) well-differentiated endometrial cancer and bilateral ovarian serous cystadenomas were discovered, estrogen replacement was given. One year later the patient presented with a 9 × 7-cm left groin recurrence. Patients with endometrial carcinoma may request estrogen replacement. The benefits of such replacement are well recognized; however, these patients also need to be counselled that hormonal replacement may be complicated by recurrence. Physicians need to be cognizant of symptoms or signs which would suggest disease recurrence at unusual sites in these patients who are perceived as being at low risk for recurrent disease.  相似文献   
66.
BACKGROUND: Worldwide, fire-related burns are a major cause of unintentional injury, morbidity and mortality, with the majority of deaths occurring in developing countries. In the US, as in other countries, most fatal fires occur in the home. Effective prevention strategies for residential fires are, however, currently underutilized. The news media is one available communication channel to promote such strategies, and analyzing current news coverage is a first step towards incorporating media advocacy into injury prevention efforts related to residential fires. METHODS: Four daily newspapers circulating widely in Maryland were monitored for 1 year. Articles describing residential fires were coded for measures of prominence, content and frame. Analysis focused on measures of issue newsworthiness, reporting of causation and consequences of fires, and inclusion of public health context and conveyance of prevention messages. RESULTS: The data indicate that fires are newsworthy, with 374 relevant news articles in a 1-year period, 32% of which appear on the first page of a section. Coverage generally concerned recent local fire events. Most articles discussed the consequences of fires (88%), and identified a causal factor (58%). Only 36%, however, included prevention information, and less than one-quarter set residential fires in a public health context. CONCLUSION: The newsworthiness of residential fires provides a clear opportunity for widespread communication around injury prevention. Improving media advocacy will entail framing discussion of recent fire events in such a way as to support inclusion of prevention strategies and a public health context in news coverage.  相似文献   
67.
68.
An evaluative research study was conducted to examine the construct validity and applicability of a selected clinical-performance-evaluation tool. The tool was designed for baccalaureate students in a community health nursing course. Eighteen senior students functioning in two urban clinical agencies participated in the study. Data were collected at two evaluation points over one semester. Results indicated strong support for construct validity of the tool. This finding suggests a high level of correlation between theoretical concepts and clinical practice. Recommendations for use of the clinical performance evaluation tool are discussed.  相似文献   
69.
70.
Chronic/relapsing experimental allergic encephalomyelitis (CREAE) serves as an animal model for relapsing/remitting multiple sclerosis. Treatment with the β-adrenergic agonist isoproterenol or the β2-adrenergic agonist terbutaline significantly suppressed both the first acute attack and the number of relapses in CREAE Lewis rats. The number of relapses was decreased even when treatment with β-adrenergic agonist was started after the onset of the first acute attack of CREAE. β-adrenergic receptor number was increased significantly on splenocytes from CREAE rats as compared to healthy controls or CFA-injected rats. Terbutaline treatment of CREAE rats lowered the splenocyte receptor number to normal values.  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