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   1099090篇
  免费   75830篇
  国内免费   3237篇
耳鼻咽喉   15175篇
儿科学   34935篇
妇产科学   28987篇
基础医学   156487篇
口腔科学   30016篇
临床医学   98444篇
内科学   207779篇
皮肤病学   24623篇
神经病学   82945篇
特种医学   43838篇
外国民族医学   222篇
外科学   165682篇
综合类   25798篇
现状与发展   6篇
一般理论   264篇
预防医学   76546篇
眼科学   25166篇
药学   88762篇
  30篇
中国医学   4210篇
肿瘤学   68242篇
  2021年   9051篇
  2019年   8711篇
  2018年   12280篇
  2017年   9826篇
  2016年   10907篇
  2015年   12497篇
  2014年   16720篇
  2013年   23519篇
  2012年   32458篇
  2011年   34410篇
  2010年   20177篇
  2009年   18775篇
  2008年   31271篇
  2007年   33311篇
  2006年   33943篇
  2005年   32274篇
  2004年   30595篇
  2003年   29240篇
  2002年   28205篇
  2001年   60516篇
  2000年   62022篇
  1999年   51585篇
  1998年   12848篇
  1997年   11393篇
  1996年   11312篇
  1995年   10586篇
  1994年   9536篇
  1993年   9005篇
  1992年   37997篇
  1991年   36442篇
  1990年   35894篇
  1989年   34427篇
  1988年   30991篇
  1987年   30099篇
  1986年   28313篇
  1985年   26538篇
  1984年   19220篇
  1983年   16142篇
  1982年   8842篇
  1979年   17045篇
  1978年   11415篇
  1977年   10232篇
  1976年   8841篇
  1975年   10073篇
  1974年   11658篇
  1973年   11275篇
  1972年   10757篇
  1971年   10101篇
  1970年   9258篇
  1969年   8940篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
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   
83.
84.
85.
摘要:抗生素的研发与使用有效杀灭和抑制了众多病原菌,挽救了无数人的生命,但由于抗生素的不合理使用,导致细菌耐 药不断出现,耐药菌的感染已严重地威胁人类的生命健康。为此,本文主要对近年来临床上常用的抗生素如β-内酰胺类、喹诺酮 类、氨基糖苷类药物以及新型抗菌药物如抗菌肽和纳米颗粒的应用研究进行总结分析与探讨,为临床上治疗疾病提供一些参考。  相似文献   
86.
87.

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   
88.
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   
89.
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   
90.
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