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   1504978篇
  免费   101350篇
  国内免费   1930篇
耳鼻咽喉   21014篇
儿科学   49180篇
妇产科学   40201篇
基础医学   224811篇
口腔科学   42014篇
临床医学   132741篇
内科学   280852篇
皮肤病学   34784篇
神经病学   111649篇
特种医学   58190篇
外国民族医学   263篇
外科学   227435篇
综合类   29101篇
现状与发展   1篇
一般理论   371篇
预防医学   108587篇
眼科学   35267篇
药学   120030篇
  7篇
中国医学   3595篇
肿瘤学   88165篇
  2018年   15341篇
  2017年   11888篇
  2016年   13393篇
  2015年   14991篇
  2014年   20334篇
  2013年   30233篇
  2012年   41297篇
  2011年   44372篇
  2010年   26005篇
  2009年   24383篇
  2008年   41545篇
  2007年   44534篇
  2006年   45273篇
  2005年   43178篇
  2004年   41656篇
  2003年   40003篇
  2002年   38867篇
  2001年   78577篇
  2000年   80818篇
  1999年   66920篇
  1998年   16926篇
  1997年   14914篇
  1996年   15138篇
  1995年   14110篇
  1994年   12888篇
  1993年   12300篇
  1992年   50452篇
  1991年   49499篇
  1990年   49124篇
  1989年   47188篇
  1988年   42828篇
  1987年   41877篇
  1986年   39464篇
  1985年   37324篇
  1984年   27296篇
  1983年   23059篇
  1982年   12756篇
  1979年   25103篇
  1978年   17344篇
  1977年   15266篇
  1976年   13745篇
  1975年   15690篇
  1974年   18429篇
  1973年   17602篇
  1972年   16961篇
  1971年   16060篇
  1970年   14784篇
  1969年   14181篇
  1968年   12908篇
  1967年   11621篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Clinical Oral Investigations - The aims of this study are to assess different saliva substitutes for their efficacy to lubricate the oral cavity, and to relate this oral lubrication to the ability...  相似文献   
102.
103.
104.
105.
106.
107.
108.

Background

Obesity is a risk factor for acetabular component malposition when total hip arthroplasty is performed with manual techniques. The utility of imageless navigation in obese patients remains unknown. This study compared the accuracy and precision of imageless navigation for component orientation between obese and nonobese patients.

Methods

A total of 459 total hip arthroplasties performed for osteoarthritis using imageless navigation were reviewed from a single surgeon’s institutional review board–approved database. Einzel-Bild-Roentgen Analyse determined component orientation on 6-week postoperative anteroposterior radiographs. Mean orientation error (accuracy) and precision were compared between obese (body mass index ≥ 30 kg/m2) and nonobese patients. Regression analysis evaluated the influence of obesity on component position.

Results

The difference in mean inclination and anteversion between obese and nonobese groups was 1.1° (43.0° ± 3.5°; range, 35.8°-57.8° vs 41.9° ± 4.4°; range, 33.0°-57.1° and 24.9° ± 6.3°; range, 14.2°-44.3° vs 23.8° ± 6.6°; range, 7.0°-38.6°, respectively). Inclination precision was better for nonobese patients. No difference in inclination accuracy or anteversion accuracy or precision was detected between groups. And 83% of components were placed within the target range. There was no relationship between obesity (dichotomized) and component placement outside the target ranges for inclination, anteversion, or both. As a continuous variable, increased body mass index correlated with higher odds of inclination outside the target zone (odds ratio, 1.06; P = .001).

Conclusion

Using imageless navigation, inclination orientation was less precise for obese patients, but the observed difference is likely not clinically relevant. Accurate superficial registration of landmarks in obese patients is achievable, and the use of imageless navigation similarly improves acetabular component positioning in obese and nonobese patients.

Level of Evidence

Therapeutic Level IV.  相似文献   
109.
At this study a multi-criteria model was developed to examine the available procedures, techniques and methods of handling infectious waste in the large healthcare unit of University Regional General Hospital of Patras, Western Greece. Particularly, this study examined the: a) current legislation and Directives issued for medical waste management at Greece and among the other EU-members, b) contribution of healthcare wastes (HCW) generation rate on social and economic parameters in selected European countries, c) available procedures, techniques, and methods upon the disposal of infectious wastes at the healthcare studied, and, d) propositions for integrated management of such hazardous wastes. Specifically, the Analytic Hierarchy Process (AHP) methodology was applied under pair wise comparison matrices in two stages: 1) the scale factors and the indicators, and 2) the criteria and their sub–criteria. The assessment of these pair wise matrices included the indicators and the sub–criteria. Subsequently, two pair wise comparison matrices, upon a) the “Fulfillment of environmental objectives” indicator and b) the “Energy consumption” sub criterion, were denoted. The AHP methodology yielded good results; however there is still space of improving the environmental performance. The normalized relative weights obtained for the criteria and sub criteria motivated specific actions that have to be handled. Particularly, the results indicated a very good value in environmental management criteria due the values obtained for the commitment towards the environmental policy standards and the waste management procedures. However, further improvements on staff awareness (such as development programs to enhance sensitivity) and more green purchasing suppliers, should be further addressed.  相似文献   
110.
Hillermann  T.  Homburg  K.  Rainer  M.  Budde  U. 《Der Anaesthesist》2022,71(4):299-302
Die Anaesthesiologie - Eine junge Patientin erleidet während der Anlage einer axillären Plexusblockade einen generalisierten Krampfanfall. Die Mechanismen, im Wesentlichen die vermutlich...  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