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   1429882篇
  免费   98877篇
  国内免费   2284篇
耳鼻咽喉   20858篇
儿科学   47743篇
妇产科学   41880篇
基础医学   208792篇
口腔科学   40318篇
临床医学   120485篇
内科学   277729篇
皮肤病学   30137篇
神经病学   113936篇
特种医学   57580篇
外国民族医学   390篇
外科学   222503篇
综合类   27440篇
现状与发展   1篇
一般理论   340篇
预防医学   100788篇
眼科学   32821篇
药学   108385篇
  1篇
中国医学   2812篇
肿瘤学   76104篇
  2018年   14490篇
  2017年   11159篇
  2016年   13021篇
  2015年   14822篇
  2014年   19509篇
  2013年   29515篇
  2012年   41066篇
  2011年   43157篇
  2010年   25555篇
  2009年   23720篇
  2008年   41952篇
  2007年   45659篇
  2006年   46228篇
  2005年   45755篇
  2004年   43740篇
  2003年   42762篇
  2002年   42083篇
  2001年   63150篇
  2000年   64671篇
  1999年   55058篇
  1998年   15684篇
  1997年   14018篇
  1996年   14020篇
  1995年   13166篇
  1994年   12527篇
  1993年   11551篇
  1992年   43158篇
  1991年   42480篇
  1990年   42016篇
  1989年   40678篇
  1988年   37833篇
  1987年   37056篇
  1986年   35294篇
  1985年   33678篇
  1984年   25165篇
  1983年   21789篇
  1982年   13051篇
  1981年   11528篇
  1979年   23839篇
  1978年   16755篇
  1977年   14504篇
  1976年   13653篇
  1975年   15153篇
  1974年   17677篇
  1973年   16978篇
  1972年   16212篇
  1971年   15081篇
  1970年   13979篇
  1969年   13428篇
  1968年   12675篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
81.
82.
83.
Background and Aims: Gastric antral vascular ectasia (GAVE) is commonly found in patients with cirrhosis, but it is also associated with other diseases in the absence of cirrhosis. Whether GAVE confers a different severity of gastrointestinal (GI) bleeding between patients with and without cirrhosis remains unknown. We aim to examine whether there is a difference in clinically significant GI bleeding due to GAVE in patients with or without cirrhosis. Methods: This is a retrospective case-control study of patients who were diagnosed with GAVE between January 2000 and June 2014. Patients were categorized into cirrhosis and noncirrhosis groups, and those with an additional GI bleeding source were excluded. Univariate comparisons and multivariable models were constructed using logistic regression. Results: In total, 110 patients diagnosed with GAVE on esophagogastroduodenoscopy (EGD) were included in our analysis; 84 patients had cirrhosis (76.4%) and 26 (23.6%) did not. Active GI bleeding was more prevalent in patients without cirrhosis (63.4% vs. 32.1%, p=0.003) despite similar indications for EGD, and endoscopic treatment with argon plasma coagulation (APC) was required more often in this group, approaching statistical significance (27% vs. 10.7%, p=0.056). There was no difference in bleeding severity, as evidenced by similar re-bleeding rates, surgery, or death attributed to uncontrolled bleeding. The strongest independent risk factor for GI bleeding was the absence of cirrhosis (odds ratio (OR): 5.151 (95% confidence interval (CI): 1.08-24.48, p=0.039). Conclusions: Patients with GAVE in the absence of cirrhosis are at higher risk for active GI bleeding and require more frequent endoscopic treatment than similar patients with cirrhosis. It may be worthwhile to treat GAVE in this population even in the absence of active bleeding.  相似文献   
84.
Health care expenditure in Germany shows clear regional differences. Such geographic variations are often seen as an indicator for inefficiency. With its homogeneous health care system, low co‐payments and uniform prices, Germany is a particularly suited example to analyse regional variations. We use data for the year 2011 on expenditure, utilization of health services and state of health in Germany's statutory health insurance system. This data, which originate from a variety of administrative sources and cover about 90% of the population, are enriched with a wealth of socio‐economic variables, data on pollutants, prices and individual preferences. State of health and demography explains 55% of the differences as measured by the standard deviation while all control variables account for a total of 72% of the differences at county level. With other measures of variation, we can account for an even greater proportion. A higher proportion of variation than usually supposed can thus be explained. Whilst this study cannot quantify inefficiencies, our results contradict the thesis that regional variations reflect inefficiency. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
85.
86.
87.
88.
89.

Background

Physicians treating nonvalvular atrial fibrillation (AF) assess stroke and bleeding risks when deciding on anticoagulation. The agreement between empirical and physician-estimated risks is unclear. Furthermore, the association between patient and physician sex and anticoagulation decision-making is uncertain.

Methods

We pooled data from 2 national primary care physician chart audit databases of patients with AF (Facilitating Review and Education to Optimize Stroke Prevention in Atrial Fibrillation and Coordinated National Network to Engage Physicians in the Care and Treatment of Patients with Atrial Fibrillation Chart Audit) with a combined 1035 physicians (133 female, 902 male) and 10,927 patients (4567 female and 6360 male).

Results

Male physicians underestimated stroke risk in female patients and overestimated risk in male patients. Female physicians estimated stroke risk well in female patients but underestimated the risk in male patients. Risk of bleeding was underestimated in all. Despite differences in risk assessment by physician and patient sex, > 90% of patients received anticoagulation across all subgroups. There was modest agreement between physician estimated and calculated (ie, CHADS2 score) stroke risk: Kappa scores were 0.41 (0.35-0.47) for female physicians and 0.34 (0.32-0.36) for male physicians.

Conclusions

Our study is the first to examine the association between patient and physician sex influences and stroke and bleeding risk estimation in AF. Although there were differences in agreement between physician estimated stroke risk and calculated CHADS2 scores, these differences were small and unlikely to affect clinical practice; further, despite any perceived differences in the accuracy of risk assessment by sex, most patients received anticoagulation.  相似文献   
90.
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