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   228551篇
  免费   65545篇
  国内免费   2448篇
耳鼻咽喉   5897篇
儿科学   9304篇
妇产科学   3098篇
基础医学   20027篇
口腔科学   6555篇
临床医学   37989篇
内科学   69217篇
皮肤病学   14150篇
神经病学   26369篇
特种医学   8251篇
外科学   53988篇
综合类   294篇
现状与发展   73篇
一般理论   30篇
预防医学   11057篇
眼科学   4467篇
药学   7150篇
中国医学   1032篇
肿瘤学   17596篇
  2024年   685篇
  2023年   4828篇
  2022年   1298篇
  2021年   4502篇
  2020年   11114篇
  2019年   13066篇
  2018年   15814篇
  2017年   17079篇
  2016年   18589篇
  2015年   18598篇
  2014年   25602篇
  2013年   26434篇
  2012年   9522篇
  2011年   9624篇
  2010年   18276篇
  2009年   18797篇
  2008年   8082篇
  2007年   5466篇
  2006年   8006篇
  2005年   5141篇
  2004年   4374篇
  2003年   3311篇
  2002年   3478篇
  2001年   4642篇
  2000年   3739篇
  1999年   3582篇
  1998年   3819篇
  1997年   3587篇
  1996年   3464篇
  1995年   3319篇
  1994年   2032篇
  1993年   1657篇
  1992年   1484篇
  1991年   1505篇
  1990年   1130篇
  1989年   1245篇
  1988年   1072篇
  1987年   920篇
  1986年   943篇
  1985年   743篇
  1984年   579篇
  1983年   555篇
  1982年   542篇
  1981年   436篇
  1980年   399篇
  1979年   336篇
  1978年   353篇
  1977年   419篇
  1975年   295篇
  1972年   317篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
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   
42.
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   
43.
44.
Dry skin (xerosis) is a common dermatosis affecting people of varying skin types and ages and various areas of the body. It is associated with both skin thickening and skin thinning and is triggered by both exogenous (e.g. climate, environment, lifestyle) and endogenous (e.g. medication, hormone fluctuations, organ diseases) factors. Skin requires a water content of 10–15% to remain supple and intact. This water is either ‘static’ (i.e. bound) or ‘dynamic’. The predominance of hydrophobic substances in intercellular constituents is a means of regulating the humidity of the skin. Emollients, highly effective treatment adjuncts in the management of all dry skin disorders, help to restore damaged intercorneocyte lipid structures and increase the water content of the skin, helping to reduce scaling and improving its barrier function.  相似文献   
45.
46.
47.
48.
49.
Abstracts     
  相似文献   
50.
PURPOSE: The beneficial role of elective neck dissection (END) in the management of high-risk cutaneous squamous cell carcinoma (CSCC) of the head and neck remains unproven. Some surgical specialists suggest that END may be beneficial for patients with clinically node-negative (N0) high-risk CSCC, but there are few data to support this claim. We reviewed the available literature regarding the use of END in the management of both CSCC and head and neck SCC (HNSCC). METHODOLOGY: The available medical literature pertaining to END in both CSCC and HNSCC was reviewed using PubMed and Ovid Medline searches. RESULTS: Many surgical specialists recommend that END be routinely performed in patients with N0 HNSCC when the risk of occult metastases is estimated to exceed 20%; however, patients who undergo END have no proven survival benefit over those who are initially staged as N0 and undergo therapeutic neck dissection (TND) after the development of apparent regional disease. There is a lack of data regarding the proper management of regional nodal basins in patients with N0 CSCC. In the absence of evidence-based data, the cutaneous surgeon must rely on clinical judgment to guide the management of patients with N0 high-risk CSCC of the head and neck. CONCLUSIONS: Appropriate work-up for occult nodal disease may occasionally be warranted in patients with high-risk CSCC. END may play a role in only a very limited number of patients with high-risk CSCC.  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