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   3628733篇
  免费   255929篇
  国内免费   9636篇
耳鼻咽喉   48971篇
儿科学   120182篇
妇产科学   99933篇
基础医学   509561篇
口腔科学   102314篇
临床医学   332445篇
内科学   707493篇
皮肤病学   85562篇
神经病学   293371篇
特种医学   137518篇
外国民族医学   941篇
外科学   541770篇
综合类   78113篇
现状与发展   10篇
一般理论   1393篇
预防医学   277494篇
眼科学   84067篇
药学   264880篇
  12篇
中国医学   8074篇
肿瘤学   200194篇
  2021年   28218篇
  2019年   28929篇
  2018年   41176篇
  2017年   31362篇
  2016年   35655篇
  2015年   40500篇
  2014年   56023篇
  2013年   83637篇
  2012年   112820篇
  2011年   119350篇
  2010年   71530篇
  2009年   67824篇
  2008年   111020篇
  2007年   118151篇
  2006年   119692篇
  2005年   114851篇
  2004年   110438篇
  2003年   106122篇
  2002年   102494篇
  2001年   175876篇
  2000年   179963篇
  1999年   151393篇
  1998年   43069篇
  1997年   37927篇
  1996年   38039篇
  1995年   36872篇
  1994年   33719篇
  1993年   31582篇
  1992年   117137篇
  1991年   112978篇
  1990年   109338篇
  1989年   105633篇
  1988年   96592篇
  1987年   94626篇
  1986年   88838篇
  1985年   84819篇
  1984年   63240篇
  1983年   53658篇
  1982年   31470篇
  1979年   55935篇
  1978年   39280篇
  1977年   33416篇
  1976年   31161篇
  1975年   32972篇
  1974年   39341篇
  1973年   37592篇
  1972年   35130篇
  1971年   32586篇
  1970年   30114篇
  1969年   28779篇
排序方式: 共有10000条查询结果,搜索用时 0 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.
5.
6.
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   
7.
8.
9.

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   
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