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   151875篇
  免费   31377篇
  国内免费   2683篇
耳鼻咽喉   5173篇
儿科学   5367篇
妇产科学   2404篇
基础医学   3260篇
口腔科学   1479篇
临床医学   26900篇
内科学   47357篇
皮肤病学   7429篇
神经病学   14830篇
特种医学   6378篇
外国民族医学   4篇
外科学   41030篇
综合类   639篇
现状与发展   73篇
预防医学   7069篇
眼科学   3385篇
药学   1141篇
  2篇
中国医学   133篇
肿瘤学   11882篇
  2024年   691篇
  2023年   4807篇
  2022年   1278篇
  2021年   3183篇
  2020年   6102篇
  2019年   2199篇
  2018年   7412篇
  2017年   7371篇
  2016年   8456篇
  2015年   8479篇
  2014年   15578篇
  2013年   15696篇
  2012年   5546篇
  2011年   5590篇
  2010年   10420篇
  2009年   14317篇
  2008年   5819篇
  2007年   4042篇
  2006年   6512篇
  2005年   3758篇
  2004年   3011篇
  2003年   1978篇
  2002年   2032篇
  2001年   3834篇
  2000年   3036篇
  1999年   3284篇
  1998年   3668篇
  1997年   3495篇
  1996年   3388篇
  1995年   3246篇
  1994年   1958篇
  1993年   1574篇
  1992年   1393篇
  1991年   1415篇
  1990年   1077篇
  1989年   1196篇
  1988年   1033篇
  1987年   855篇
  1986年   896篇
  1985年   727篇
  1984年   546篇
  1983年   519篇
  1982年   516篇
  1981年   404篇
  1980年   363篇
  1979年   313篇
  1978年   330篇
  1977年   396篇
  1975年   279篇
  1972年   302篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
63.
OBJECTIVE: To obtain consensus among a panel of experts on performance measures useful for evaluating the quality of hospital-based domestic violence (DV) programs. METHODS: The Delphi process of consensus development was used with a panel of 18 experts including DV researchers, program planners, and advocates. Three rounds were conducted over a period of six months, with each round involving the completion of a written questionnaire. Panelists were instructed to concentrate on structure and process measures of DV program performance. Health outcome measures were not considered. During each round, panelists rated (scale of 1-5) their level of agreement with each measure, in terms of the measure's usefulness for evaluating hospital-based DV programs. Data were entered into SPSS on a personal computer and frequency distributions, measures of central tendency, and variance were computed for each measure. Consensus development was defined as a reduction in the item-specific variance from one round to the next. RESULTS: A total of 37 performance measures were agreed upon. These measures fell within nine different domains of DV program activities, including: Policies and Procedures, Hospital Physical Environment, Hospital Cultural Environment, Training of Providers, Screening and Safety Assessment, Documentation, Intervention Services, Evaluation Activities, and Collaboration. CONCLUSIONS: A number of measures have been identified as useful for evaluating hospital-based DV programs. Use of these measures should assist researchers, program planners, and administrators in assessing the quality of hospital-based DV programs.  相似文献   
64.
This paper reports the proceedings of the discussion panel assigned to look at clinical aspects of quality in emergency medicine. One of the seven stated objectives of the Academic Emergency Medicine consensus conference on quality in emergency medicine was to educate emergency physicians regarding quality measures and quality improvement as essential aspects of the practice of emergency medicine. Another topic of interest was a discussion of the value of information technology in facilitating quality care in the clinical practice of emergency medicine. It is important to note that this is not intended to be a comprehensive review of this extensive topic, but instead is designed to report the discussion that occurred at this session of the consensus conference.  相似文献   
65.
66.
This study evaluates the potential for endothelial seeding of a collagen-impregnated Dacron graft with or without surface modifiers (fibronectin, heparin) to attach and retain these cells during flow. Human umbilical endothelial cells were harvested, cultured, labeled with Indium111-oxine and seeded onto 30 mm X 4 mm diameter grafts. Six graft surfaces were studied: 1) a collagen-impregnated Dacron graft, HemashieldR (C); 2) C + fibronectin (C + F); 3) C + heparin (C + H); 4) C + F + H; 5) HytrelR + F (Hyt + F); and 6) Hyt + F + H. Radioactive loss determined the percentage attachment and then percentage retention of labeled inoculum after a one-hour in vitro perfusion. Scanning electron and light microscopy demonstrated the endothelium on the graft surface following perfusion. Fibronectin-coated grafts had a significantly higher percentage attachment than those without fibronectin (ANOVA, P less than 0.05). However, the percentage retention following perfusion was similar for all Dacron grafts and statistically inferior to the HytrelR grafts studied (ANOVA, P less than 0.05). SEM evaluation of the C + F + H graft surface was qualitatively the most impressive Dacron surface for seeding, yet was inferior to the HytrelR graft. We conclude that fibronectin benefits the initial attachment of endothelium to collagen-coated Dacron rivaling the HytrelR surface. Fibronectin does not improve percentage retention of the HemashieldR surface during perfusion, therefore, some of its initial benefit is lost.  相似文献   
67.
Infantile Digital Fibroma Treated With Mohs Micrographic Surgery   总被引:2,自引:0,他引:2  
John G. Albertini  MD  Maj  USAF  MC  Michael Jude Welsch  MD  CPT  USA  MC  Leo A. Conger  MD  LTC  USA  MC  Lester F. Libow  MD  COL  USA  MC    Dirk M. Elston  MD  COL  USA  MC 《Dermatologic surgery》2002,28(10):959-961
BACKGROUND: Infantile digital fibroma (IDF) is a rare benign fibrous tumor of childhood that frequently recurs despite local excision. Conservative, nonsurgical management may result in regression and/or joint deformity. OBJECTIVE: To describe the histologic features of IDF and discuss a case excised using Mohs micrographic surgery (MMS). METHODS: Case report and review of the clinical, histologic, and ultrastructural features. RESULTS: Characteristic inclusion bodies of actin were identified with hematoxylin and eosin, Masson's trichrome, and rapid actin immunostain. The tumor was debulked and the majority was removed after one stage of MMS, except where the deep margin approached the joint space. The defect healed by secondary intention. At 2 years the patient had no recurrence or functional joint deformity. CONCLUSION: MMS is a surgical treatment option for IDF.  相似文献   
68.
Objective: The study goal was to compare the laser spot size created using reflective and refractive micromanipulators with a CO2 laser and to determine the sensitivity of spot size to laser power. Study Design and Setting: A CO2 laser and operating microscope (400-mm focal length) was coupled to either a reflective (Cassegrain-like) or refractive micromanipulator. Laser spot size was determined by measuring the region of ablation created by laser irradiation of wood (dry tongue depressors), exposed photographic film, and agar gel using optical micrometry. Laser power varied from 0.5 to 20 W with pulse durations of 0.1 and 0.5 second. Results: The reflective micromanipulator demonstrated overall smaller spot sizes for a given laser power and lower incremental change in spot size with increasing power. The reflective design demonstrated less sensitivity to increases in laser power. Conclusions: Micromanipulator optical design can result in significant differences in laser spot size. The reflective device used in this study demonstrated less sensitivity to increasing laser power. (Otolaryngol Head Neck Surg 2002;126:593-597.)  相似文献   
69.
70.
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