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   2919226篇
  免费   200343篇
  国内免费   7862篇
耳鼻咽喉   38900篇
儿科学   95860篇
妇产科学   79637篇
基础医学   421029篇
口腔科学   78018篇
临床医学   265954篇
内科学   571890篇
皮肤病学   69775篇
神经病学   233984篇
特种医学   111849篇
外国民族医学   774篇
外科学   435403篇
综合类   55761篇
现状与发展   6篇
一般理论   1043篇
预防医学   221878篇
眼科学   64912篇
药学   213824篇
  9篇
中国医学   5962篇
肿瘤学   160963篇
  2019年   22804篇
  2018年   32505篇
  2017年   24911篇
  2016年   28961篇
  2015年   32534篇
  2014年   44550篇
  2013年   66638篇
  2012年   89401篇
  2011年   95004篇
  2010年   57111篇
  2009年   54332篇
  2008年   88482篇
  2007年   94354篇
  2006年   95801篇
  2005年   91611篇
  2004年   88287篇
  2003年   85418篇
  2002年   82403篇
  2001年   139986篇
  2000年   143253篇
  1999年   120588篇
  1998年   34348篇
  1997年   30426篇
  1996年   30704篇
  1995年   29666篇
  1994年   27181篇
  1993年   25589篇
  1992年   93394篇
  1991年   91042篇
  1990年   88385篇
  1989年   85591篇
  1988年   78391篇
  1987年   76853篇
  1986年   71889篇
  1985年   68730篇
  1984年   51034篇
  1983年   43138篇
  1982年   25150篇
  1981年   22527篇
  1979年   45101篇
  1978年   31826篇
  1977年   26807篇
  1976年   25348篇
  1975年   27462篇
  1974年   32082篇
  1973年   30498篇
  1972年   28514篇
  1971年   26588篇
  1970年   24559篇
  1969年   23548篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
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   
3.
4.
Pharmaceutical Chemistry Journal - An HPLC-MS method for simultaneous quantitative determination of a novel gestagenic pharmaceutical and two of its metabolites in rat and rabbit blood sera was...  相似文献   
5.
6.

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   
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