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   2439902篇
  免费   196125篇
  国内免费   8224篇
耳鼻咽喉   32056篇
儿科学   80234篇
妇产科学   68367篇
基础医学   340350篇
口腔科学   66886篇
临床医学   221681篇
内科学   490877篇
皮肤病学   57958篇
神经病学   202396篇
特种医学   96108篇
外国民族医学   709篇
外科学   370621篇
综合类   58195篇
现状与发展   4篇
一般理论   845篇
预防医学   195676篇
眼科学   54054篇
药学   171167篇
  6篇
中国医学   5008篇
肿瘤学   131053篇
  2018年   26615篇
  2017年   20600篇
  2016年   23929篇
  2015年   26767篇
  2014年   37739篇
  2013年   56445篇
  2012年   72760篇
  2011年   77946篇
  2010年   47266篇
  2009年   45543篇
  2008年   72348篇
  2007年   76729篇
  2006年   77947篇
  2005年   75633篇
  2004年   72265篇
  2003年   69464篇
  2002年   66519篇
  2001年   118800篇
  2000年   121791篇
  1999年   101432篇
  1998年   29924篇
  1997年   26940篇
  1996年   27697篇
  1995年   27089篇
  1994年   24917篇
  1993年   23436篇
  1992年   80382篇
  1991年   77566篇
  1990年   74495篇
  1989年   70982篇
  1988年   65545篇
  1987年   64200篇
  1986年   60350篇
  1985年   57981篇
  1984年   44237篇
  1983年   37351篇
  1982年   23146篇
  1981年   20681篇
  1980年   19261篇
  1979年   39595篇
  1978年   28340篇
  1977年   23747篇
  1976年   22030篇
  1975年   22814篇
  1974年   27135篇
  1973年   26087篇
  1972年   24387篇
  1971年   22334篇
  1970年   20851篇
  1969年   19402篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
BackgroundThe aim of this study was to estimate the prevalence of dental prosthetic treatment and to investigate the demographic, social, economic and medical factors associated with the use of fixed and removable dentures in a representative sample of adults living in France.MethodsThe data were obtained from the 2002–2003 Decennial Health Survey, a cross-sectional study of a representative sample of the population living in France, which included 29,679 adults. Information was collected by interview. The variables collected were fixed denture, removable denture, age, gender, number of children, area of residence, nationality, educational attainment, family social status, employment status, annual household income per capita, supplementary insurance, chronic disease, eyesight problems/glasses, hearing problems/hearing aids. Multinomial logistic regression models were used to study the relationship between prosthetic treatment and demographic, socioeconomic and medical characteristics unadjusted, adjusted for age and adjusted for all the characteristics.ResultsThe prevalence of prosthetic treatment was 34.6% (95% confidence interval (CI): [34.1; 35.2]) for fixed prosthetic dentures and 13.8% (95% CI: [13.4; 14.2]) for removable prosthetic dentures. We showed a gradient between educational attainment and removable dentures; the odds ratio adjusted for all the variables (aOR) associated with no or primary education compared to post-secondary education was 2.56; 95% CI: [2.09; 3.13]. When annual household income per capita was low, subjects were less likely to report fixed dentures (aOR = 0.68; 95% CI: [0.62; 0.75]) than those with high annual household income per capita. Individuals without insurance less often reported fixed dentures than those with private insurance. Those reporting chronic disease were less likely to report fixed dentures (aOR = 0.87; 95% CI: [0.79; 0.95]) but more likely to report removable dentures (aOR = 1.29; 95% CI: [1.17; 1.43]) than those without chronic disease.ConclusionThis study reveals social, economic and medical inequalities in fixed and removable prosthetic treatment among adults in France.  相似文献   
2.
3.
4.
5.

Objectives

Expedient extubation after cardiac surgery has been associated with improved outcomes, leading to postoperative extubation frequently during overnight hours. However, recent evidence in a mixed medical-surgical intensive care unit population demonstrated worse outcomes with overnight extubation. This study investigated the impact of overnight extubation in a statewide, multicenter Society of Thoracic Surgeons database.

Methods

Records from 39,812 patients undergoing coronary artery bypass grafting or valve operations (2008-2016) and extubated within 24 hours were stratified according to extubation time between 06:00 and 18:00 (day) or between 18:00 and 6:00 (overnight). Outcomes including reintubation, mortality, and composite morbidity-mortality were evaluated using hierarchical regression models adjusted for Society of Thoracic Surgeons predictive risk scores. To further analyze extubation during the night, a subanalysis stratified patients into 3 groups: 06:00 to 18:00, 18:00 to 24:00, and 24:00 to 06:00.

Results

A total of 20,758 patients were extubated overnight (52.1%) and were slightly older (median age 66 vs 65 years, P < .001) with a longer duration of ventilation (4 vs 7 hours, P < .001). Day and overnight extubation were associated with equivalent operative mortality (1.7% vs 1.7%, P = .880), reintubation (3.7% vs 3.4%, P = .141), and composite morbidity-mortality (8.2% vs 8.0%, P = .314). After risk adjustment, overnight extubation was not associated with any difference in reintubation, mortality, or composite morbidity-mortality. On subanalysis, those extubated between 24:00 and 06:00 exhibited increased composite morbidity-mortality (odds ratio, 1.18; P = .001) but no difference in reintubation or mortality.

Conclusions

Extubation overnight was not associated with increased mortality or reintubation. These results suggest that in the appropriate clinical setting, it is safe to routinely extubate cardiac surgery patients overnight.  相似文献   
6.
Metabolism describes the series of chemical reactions that are concerned with the provision of energy to biological systems. They may be divided into reactions involved in energy yield (catabolism: demand exceeds supply), and energy storage (anabolism: supply exceeds demand). Regulation of these pathways is critical for homeostasis, and derangements in metabolism are seen in a wide variety of pathological processes. Understanding metabolism is key to the treatment of many diseases, notably diabetes, as well as underpinning clinical nutritional support.  相似文献   
7.
8.
9.
10.
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