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   59140篇
  免费   3874篇
  国内免费   678篇
耳鼻咽喉   1152篇
儿科学   840篇
妇产科学   1107篇
基础医学   9118篇
口腔科学   1294篇
临床医学   5130篇
内科学   12250篇
皮肤病学   1887篇
神经病学   4293篇
特种医学   3228篇
外科学   7556篇
综合类   668篇
现状与发展   3篇
一般理论   27篇
预防医学   2494篇
眼科学   1376篇
药学   5464篇
中国医学   727篇
肿瘤学   5078篇
  2023年   418篇
  2022年   1266篇
  2021年   2037篇
  2020年   1052篇
  2019年   1545篇
  2018年   1820篇
  2017年   1354篇
  2016年   1913篇
  2015年   2587篇
  2014年   2897篇
  2013年   3396篇
  2012年   5002篇
  2011年   4872篇
  2010年   2950篇
  2009年   2435篇
  2008年   3442篇
  2007年   3180篇
  2006年   2825篇
  2005年   2708篇
  2004年   2220篇
  2003年   2070篇
  2002年   1822篇
  2001年   1238篇
  2000年   1122篇
  1999年   1003篇
  1998年   410篇
  1997年   360篇
  1996年   306篇
  1995年   252篇
  1994年   225篇
  1993年   168篇
  1992年   434篇
  1991年   371篇
  1990年   382篇
  1989年   360篇
  1988年   338篇
  1987年   279篇
  1986年   264篇
  1985年   232篇
  1984年   192篇
  1983年   151篇
  1982年   106篇
  1981年   98篇
  1980年   95篇
  1979年   179篇
  1978年   127篇
  1977年   94篇
  1975年   113篇
  1972年   92篇
  1971年   94篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
Direct peroral cholangioscopy (POC) using an ultra‐slim upper endoscope is one modality of POC for intraductal endoscopic evaluation and treatment of the bile duct. Choledochoduodenostomy (CDS) is one modality of biliary bypass surgery that provides a new route to the bile duct. We carried out direct POC using an ultra‐slim upper endoscope without the use of accessories in 10 patients (four sump syndromes, three bile duct strictures and three intrahepatic duct stones) previously undergoing surgical CDS. Direct POC was successful in all patients. The use of an intraductal balloon catheter was required in one patient for advancement of the endoscope into the bile duct. Distal bile ducts with sump syndromes were cleared using baskets and water irrigation under direct POC. Cholangiocarcinoma was diagnosed in one patient with hilar bile duct stricture after cholangioscopic evaluation and a targeting forceps biopsy under direct POC. Intrahepatic duct stones were successfully extracted after intraductal fragmentation under direct POC. Oozing bleeding occurred during intraductal lithotripsy but stopped spontaneously. Direct POC using an ultra‐slim upper endoscope without the assistance of accessories can easily be carried out in patients undergoing CDS.  相似文献   
2.
3.
Scrub typhus usually presents as acute undifferentiated fever. This cross-sectional study included adult patients presenting with acute undifferentiated fever defined as any febrile illness for ≤ 14 days without evidence of localized infection. Scrub typhus cases were defined by an antibody titer of a ≥ fourfold increase in paired sera, a ≥ 1:160 in a single serum using indirect immunofluorescence assay, or a positive result of the immunochromatographic test. Multiple regression analysis identified predictors associated with scrub typhus to develop a prediction rule. Of 250 cases with known etiology of acute undifferentiated fever, influenza (28.0%), hepatitis A (25.2%), and scrub typhus (16.4%) were major causes. A prediction rule for identifying suspected cases of scrub typhus consisted of age ≥ 65 years (two points), recent fieldwork/outdoor activities (one point), onset of illness during an outbreak period (two points), myalgia (one point), and eschar (two points). The c statistic was 0.977 (95% confidence interval = 0.960–0.994). At a cutoff value ≥ 4, the sensitivity and specificity were 92.7% (79.0–98.1%) and 90.9% (86.0–94.3%), respectively. Scrub typhus, the third leading cause of acute undifferentiated fever in our region, can be identified early using the prediction rule.  相似文献   
4.
5.
6.
7.
8.
Acid-suppressive drugs, including histamine-2 receptor antagonists (H2RAs) and proton pump inhibitors (PPIs), are common medications used for treating upper gastrointestinal tract disorders. However, acid-suppressive drugs have been reported to increase the risk of pneumonia in numerous disease populations. However, the relationship between acid-suppressive drugs and stroke-associated pneumonia (SAP) remains controversial.The purpose of this study was to investigate the association between acid-suppressive drug usage and pneumonia among patients with stroke by using a nationwide data set.A population-based cohort study was conducted using a data set from the Taiwanese National Health Insurance Research Database. Data on patients with new-onset stroke from 2010 to 2011 were collected. Patients with and without acid-suppressive drug usage were followed up to identify the occurrence of any type of pneumonia. We estimated the adjusted hazard ratios (HRs) by using the Cox proportional hazards model.The study cohort comprised 7965 patients with new-onset stroke. The incidence of pneumonia was 6.9% (552/7965) and more than 40% (225/552) of patients developed pneumonia within 3 months after an acute stroke. Acid-suppressive drug usage was an independent risk factor of pneumonia. The adjusted HR for the risk of pneumonia in patients with new-onset stroke using acid-suppressive drugs was 1.44 (95% confidence interval [CI] = 1.18–1.75, P < 0.01). Only PPI usage increased risk of chronic SAP (adjusted HR = 1.46, 95% CI = 1.04–2.05).Acid-suppressive drug usage was associated with a slightly increased risk of SAP. Physicians should exercise caution when prescribing acid-suppressive drugs to patients with stroke, particularly at the chronic stage.  相似文献   
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