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   3123803篇
  免费   219772篇
  国内免费   8677篇
耳鼻咽喉   42706篇
儿科学   102488篇
妇产科学   87285篇
基础医学   438642篇
口腔科学   86050篇
临床医学   281033篇
内科学   615278篇
皮肤病学   73278篇
神经病学   255416篇
特种医学   121225篇
外国民族医学   1019篇
外科学   470559篇
综合类   63762篇
现状与发展   5篇
一般理论   1167篇
预防医学   238260篇
眼科学   70434篇
药学   227185篇
  8篇
中国医学   6379篇
肿瘤学   170073篇
  2019年   24229篇
  2018年   34144篇
  2017年   26373篇
  2016年   30275篇
  2015年   34077篇
  2014年   47313篇
  2013年   71254篇
  2012年   94705篇
  2011年   100272篇
  2010年   60661篇
  2009年   58068篇
  2008年   94063篇
  2007年   99699篇
  2006年   101550篇
  2005年   97666篇
  2004年   93860篇
  2003年   90768篇
  2002年   87841篇
  2001年   148389篇
  2000年   151869篇
  1999年   128549篇
  1998年   36861篇
  1997年   32898篇
  1996年   33032篇
  1995年   31720篇
  1994年   29261篇
  1993年   27548篇
  1992年   100109篇
  1991年   96205篇
  1990年   93355篇
  1989年   90331篇
  1988年   82840篇
  1987年   81229篇
  1986年   76531篇
  1985年   72908篇
  1984年   54498篇
  1983年   46306篇
  1982年   27606篇
  1981年   24514篇
  1979年   48550篇
  1978年   34319篇
  1977年   29046篇
  1976年   27132篇
  1975年   29007篇
  1974年   34389篇
  1973年   32869篇
  1972年   30840篇
  1971年   28493篇
  1970年   26605篇
  1969年   25485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.
Graefe's Archive for Clinical and Experimental Ophthalmology - The published online version contains mistake as the author's first name and last name have been interchanged as "Hild...  相似文献   
5.
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   
6.
7.

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   
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