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   3544725篇
  免费   242576篇
  国内免费   9732篇
耳鼻咽喉   49928篇
儿科学   115747篇
妇产科学   100745篇
基础医学   496483篇
口腔科学   100691篇
临床医学   317528篇
内科学   688833篇
皮肤病学   84255篇
神经病学   286536篇
特种医学   139056篇
外国民族医学   1192篇
外科学   533862篇
综合类   73570篇
现状与发展   11篇
一般理论   1302篇
预防医学   267239篇
眼科学   81835篇
药学   260081篇
  14篇
中国医学   7204篇
肿瘤学   190921篇
  2018年   38751篇
  2017年   30989篇
  2016年   34581篇
  2015年   39849篇
  2014年   53147篇
  2013年   77930篇
  2012年   106590篇
  2011年   108784篇
  2010年   65235篇
  2009年   63703篇
  2008年   100635篇
  2007年   108035篇
  2006年   109754篇
  2005年   112048篇
  2004年   109858篇
  2003年   103119篇
  2002年   96140篇
  2001年   162285篇
  2000年   165479篇
  1999年   141436篇
  1998年   40398篇
  1997年   35932篇
  1996年   35586篇
  1995年   34363篇
  1994年   31681篇
  1993年   29698篇
  1992年   111688篇
  1991年   108308篇
  1990年   105478篇
  1989年   102389篇
  1988年   94467篇
  1987年   92748篇
  1986年   87649篇
  1985年   83529篇
  1984年   62496篇
  1983年   53057篇
  1982年   31417篇
  1981年   28100篇
  1979年   57250篇
  1978年   40470篇
  1977年   34754篇
  1976年   31854篇
  1975年   35342篇
  1974年   41865篇
  1973年   40081篇
  1972年   37942篇
  1971年   35598篇
  1970年   33185篇
  1969年   32019篇
  1968年   29742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