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   8763篇
  免费   841篇
  国内免费   19篇
耳鼻咽喉   213篇
儿科学   218篇
妇产科学   381篇
基础医学   876篇
口腔科学   174篇
临床医学   809篇
内科学   1880篇
皮肤病学   219篇
神经病学   750篇
特种医学   523篇
外国民族医学   2篇
外科学   1439篇
综合类   131篇
一般理论   3篇
预防医学   684篇
眼科学   264篇
药学   351篇
中国医学   5篇
肿瘤学   701篇
  2021年   74篇
  2019年   100篇
  2018年   111篇
  2017年   94篇
  2016年   117篇
  2015年   125篇
  2014年   174篇
  2013年   241篇
  2012年   325篇
  2011年   349篇
  2010年   209篇
  2009年   172篇
  2008年   301篇
  2007年   343篇
  2006年   373篇
  2005年   342篇
  2004年   316篇
  2003年   337篇
  2002年   291篇
  2001年   266篇
  2000年   319篇
  1999年   279篇
  1998年   121篇
  1997年   108篇
  1996年   90篇
  1995年   86篇
  1994年   88篇
  1993年   77篇
  1992年   217篇
  1991年   227篇
  1990年   230篇
  1989年   206篇
  1988年   190篇
  1987年   181篇
  1986年   202篇
  1985年   200篇
  1984年   135篇
  1983年   131篇
  1982年   92篇
  1981年   89篇
  1980年   76篇
  1979年   155篇
  1978年   106篇
  1977年   112篇
  1976年   93篇
  1975年   103篇
  1974年   129篇
  1973年   109篇
  1972年   97篇
  1971年   74篇
排序方式: 共有9623条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Introduction Patients with cystic fibrosis (CF) are known to be at risk for early osteoporosis, and the mechanisms that mediate bone loss are still being delineated. The aim of the present investigation was to investigate if a correlation exists in these patients between skeletal measurements by dual-energy x-ray absorptiometry (DXA) and two anabolic factors, dehydroepiandrosterone (DHEA) and insulin-like growth factor I (IGF-I), and proresorptive factors such as the cytokines interleukin-1β, tumor necrosis factor α, and interleukin-6. Methods We studied 32 outpatients (18 females; mean age: 26.2 ± 7.9 years) at a tertiary care medical center. The subjects had venous samples obtained, underwent anthropometric and bone mineral density (BMD) measurements, and completed a health survey. Serum IGF-I concentrations were below the age-adjusted mean in 78% of the participants, and DHEA sulfate (DHEAS) concentrations were low in 72%. Serum concentrations of all cytokines were on the low side of normal; nonetheless, there was a modest inverse correlation between IL-1β and BMD at all sites. Results In univariate analyses, IGF-I and DHEAS were significant correlates of BMD or bone mineral content. In final multivariate models controlling for anthropometric and other variables of relevance to bone density, only IGF-I was identified as a significant independent skeletal predictor. While alterations in DHEAS, IGF-I, and specific cytokines may contribute to skeletal deficits in patients with CF, of these factors a low IGF-I concentration appears to be most strongly correlated with BMD. Conclusions These findings may have therapeutic implications for enhancing bone density in these patients.  相似文献   
5.
PURPOSE: Chart notes are used to support billing codes under the evaluation and management guidelines of the Health Care Financing Administration (HCFA), in addition to serving as a record of the visit. To better understand the effect of the HCFA documentation guidelines, the authors collected data on how the guidelines affect participation by university- and community-based faculty in clinical education programs. METHOD: In 2000, the authors sent six copies of their questionnaire to the associate deans of the 125 U.S. medical schools and requested they distribute them to all core clerkship directors. The questionnaire consisted of multiple-choice and short-answer questions regarding documentation of medical visits, participation of community-based faculty, understanding of HCFA documentation guidelines, and effects on education programs. RESULTS: The response rate was about 50%. Most of the 379 clerkship directors who responded (77%) stated they were aware the HCFA documentation guidelines include specifications regarding the role medical students can play and documentation of medical visits, and 64% indicated they were concerned the guidelines would affect their educational programs. Concerns included the loss of student independence and active participation in the patient care environment (37), time constraints and the changing balance between education and service (16), loss of faculty and decreased morale (11), and decreased quality of care for patients (7). CONCLUSION: Leaders of medical education must work to modify these guidelines to protect the quality of patients' care, while maximizing students' educational opportunity and participation.  相似文献   
6.
7.
8.
9.
10.
A provisional set of standards of care was derived from a quality assurance strand of a wider research project, which reported the development of evaluation strategies for area integrated mental health services (AIMHS). In contrast to most published standards, they apply to all facets of care in a comprehensive catchment area mental health service, whether clinical or functional, community or hospital based, urban or rural, or managed by the public, private or voluntary sectors. We review briefly existing sets of standards of mental health services and report the process of development of standards of care, each with sub-sets of performance indicators and examples. While the AIMHS standards and a companion quality assurance manual are still undergoing refinement, they offer a guide for mental health professionals to the provision of services, and a checklist to service-users of services that should be available to them at every stage of care in a mental health system.  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