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   66402篇
  免费   9283篇
  国内免费   311篇
耳鼻咽喉   984篇
儿科学   2103篇
妇产科学   1875篇
基础医学   6837篇
口腔科学   3227篇
临床医学   9057篇
内科学   14429篇
皮肤病学   1320篇
神经病学   7269篇
特种医学   2084篇
外科学   7833篇
综合类   431篇
现状与发展   12篇
一般理论   58篇
预防医学   8132篇
眼科学   924篇
药学   3131篇
中国医学   91篇
肿瘤学   6199篇
  2024年   175篇
  2023年   1655篇
  2022年   975篇
  2021年   2747篇
  2020年   2470篇
  2019年   2228篇
  2018年   3318篇
  2017年   2621篇
  2016年   2971篇
  2015年   3179篇
  2014年   3940篇
  2013年   4927篇
  2012年   4921篇
  2011年   4846篇
  2010年   3414篇
  2009年   3744篇
  2008年   3660篇
  2007年   3377篇
  2006年   3388篇
  2005年   3003篇
  2004年   2579篇
  2003年   2306篇
  2002年   1971篇
  2001年   563篇
  2000年   411篇
  1999年   581篇
  1998年   843篇
  1997年   734篇
  1996年   739篇
  1995年   560篇
  1994年   422篇
  1993年   374篇
  1992年   240篇
  1991年   217篇
  1990年   190篇
  1989年   197篇
  1988年   171篇
  1987年   156篇
  1986年   136篇
  1985年   126篇
  1984年   121篇
  1983年   133篇
  1982年   115篇
  1981年   106篇
  1980年   73篇
  1979年   49篇
  1978年   45篇
  1977年   63篇
  1976年   39篇
  1975年   36篇
排序方式: 共有10000条查询结果,搜索用时 281 毫秒
51.
52.
53.
54.
55.
56.
Background and study aimsThe COVID-19 outbreak has reorganized surgical team conditions regarding endoscopy. The number of interventions has been reduced, the number of healthcare professionals must be limited, and both the patients and physicians are more protected than ever.Patients and MethodsIn the highest peak of contagion in Colombia, endoscopy, colonoscopy, and esophagogastroduodenoscopy were performed using a low-cost disposable device. A total of 1388 procedures were performed. Every patient was assessed for symptoms via a telephone call, at the health center, and after the procedure, following specific attention routes.ResultsAfter procedure follow-up, no positive cases of COVID-19 were noted.ConclusionThe methodology reduced the risk of infection during the COVID-19 pandemic.  相似文献   
57.
PURPOSE: The purpose of this study was to compare the dentin/adhesive interfacial characteristics when bonding to noncarious as well as caries-affected dentin. MATERIALS AND METHODS: Seven extracted, unerupted, third molars were sectioned into halves. Artificial caries was created on one-half of each tooth, leaving the other half as a control. Dentin surfaces were treated with UNO adhesive according to the manufacturer's instructions for the wet-bonding technique and under environmental conditions present in the oral cavity. Dentin/adhesive interface sections of each half-tooth were stained with Goldner's trichrome, a classic bone stain, and examined using light microscopy. The width of exposed collagen was measured directly from photomicrographs, and adhesive penetration was analyzed qualitatively. RESULTS: The degree and extent to which the adhesive encapsulated the demineralized dentin matrix were reflected in the color difference in the stained sections with the noncarious dentin sections showing a degree of collagen encapsulation superior to that of the caries-affected dentin sections. The overall mean widths of exposed collagen were significantly (p < or = .05) greater at the caries-affected dentin/adhesive interface, 8.6 (1.7) microm, as compared with those at the noncarious dentin/adhesive interface, 6.0 (1.5) microm. CONCLUSIONS: The morphologic characteristics of the caries-affected dentin/interface suggest an increase in the exposed collagen zone and a decrease in the quality of the adhesive infiltration when compared with noncarious dentin. The evidence suggests that dentin substrate characteristics have a significant effect on the dentin/adhesive interface structure.  相似文献   
58.
The intention of this article is to introduce the reader to the Transograph from a historical perspective. The technical data presented are intended to help the reader understand the design of this unique instrument and how it was programmed, but will not provide the reader a thorough understanding of this philosophy. The article seeks neither to defend nor criticize the principles of Transographics.  相似文献   
59.
60.
The clinical syndrome of tuberculous (TB) meningitis leading to ischemic strokes is rarely seen today in immunocompetent adults native to North America. This entity is also notoriously difficult to diagnose because the presenting symptoms are often nonspecific. The authors describe a case of a man with TB meningitis which progressed to recurrent ischemic cerebral infarcts.  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