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   939篇
  免费   27篇
  国内免费   11篇
耳鼻咽喉   1篇
儿科学   75篇
妇产科学   7篇
基础医学   64篇
口腔科学   10篇
临床医学   60篇
内科学   152篇
皮肤病学   29篇
神经病学   3篇
特种医学   98篇
外科学   107篇
综合类   259篇
预防医学   30篇
眼科学   4篇
药学   32篇
肿瘤学   46篇
  2023年   2篇
  2022年   4篇
  2021年   10篇
  2020年   6篇
  2019年   6篇
  2018年   12篇
  2017年   10篇
  2016年   9篇
  2015年   29篇
  2014年   17篇
  2013年   21篇
  2012年   24篇
  2011年   15篇
  2010年   52篇
  2009年   48篇
  2008年   35篇
  2007年   48篇
  2006年   70篇
  2005年   42篇
  2004年   54篇
  2003年   27篇
  2002年   28篇
  2001年   19篇
  2000年   21篇
  1999年   29篇
  1998年   40篇
  1997年   50篇
  1996年   54篇
  1995年   33篇
  1994年   31篇
  1993年   9篇
  1992年   11篇
  1991年   7篇
  1990年   8篇
  1989年   8篇
  1988年   16篇
  1987年   12篇
  1986年   10篇
  1985年   7篇
  1984年   11篇
  1983年   4篇
  1982年   7篇
  1981年   6篇
  1980年   4篇
  1978年   3篇
  1977年   4篇
  1976年   2篇
  1975年   2篇
排序方式: 共有977条查询结果,搜索用时 46 毫秒
101.
Background and Aim:  A major challenge in neonatal cholestasis (NC) is to differentiate biliary atresia (BA) from other non-atretic causes. In developing countries there are considerable problems of late referral of NC cases and performing surgery without prelaparotomy liver biopsy that contributes to a high proportion of negative laparotomy and increased morbidity. We evaluated the hepatic histopathology for presence of features that correlate best with the diagnosis of BA and assessed the accuracy of percutaneous liver biopsy.
Methods:  Fifty-five cases of NC that fulfilled the selection criteria and had liver biopsy available were analyzed. Among the 49 adequate liver biopsies, 28 cases were diagnosed as BA, 15 neonatal hepatitis (NH) and 6 were due to other causes. Validity of percutaneous liver biopsy diagnoses was compared with confirmed cases by laparotomy findings and 1-year follow up. Twelve histological parameters of confirmed cases of BA and NH were evaluated by logistic regression analyses.
Results:  Ductular proliferation ( P  = 0.0002), bile duct and ductular bile plugs ( P  = 0.009), and portal fibrosis ( P  = 0.002) were the best indicators of BA and among them ductular proliferation was the most important in distinguishing BA from NH. Ductal plate malformation was observed in 17.9% cases of BA. Sensitivity and specificity of percutaneous liver biopsy for diagnosing BA was 88.2% each.
Conclusion:  Percutaneous liver biopsy is highly accurate (88.2%) in diagnosing BA. In developing countries. This investigation should be done to decrease the frequency of negative laparotomy and to achieve cost–benefit with reduced morbidity.  相似文献   
102.
Introduction: We assessed cardiac function (CF) in celiac disease (CD) patients and the effect of gluten-free diet (GFD) on CF.

Methods: Prospective evaluation of CF using conventional and tissue doppler echocardiography in 50 CD patients (age 4.2?±?1.1 years) at diagnosis and after a year of GFD (group 1), 100 CD children (group 2; 47 compliant and 53 non-compliant) in follow-up and 25 healthy controls.

Results: Untreated CD (n?=?50) children had larger left ventricle end diastolic dimension (35.33?±?0.87 vs. 32.90?±?0.91 mm; p?=?.04), reduced (<55%) left ventricular ejection fraction (20% vs. 0%; p?=?.01) and a higher (>0.6) myocardial performance index (MPI, 66% vs. 0%; p ≤ .01) as compared to controls. Re-evaluation after one year with good dietary compliance showed changes in isovolumic relaxation time (72.5?±?4.2 vs. 50.62?±?2.69; p?=?.0001) and deceleration time (121.05?±?10.1 vs. 99.87?±?8.5; p?=?.02), reflecting improved cardiac diastolic function. GFD compliant patients had lower MPI than non-compliant (0.60?±?.03 vs. 0.66?±?.08; p?=?.04), reflecting improvement in load-independent echocardiographic parameters.

Conclusions: Subclinical cardiac dysfunction is common in CD children at diagnosis. Improvement

in echocardiographic parameters occurs with GFD and non-compliant children continue to have

persistent cardiac dysfunction.  相似文献   
103.
104.
Dyspepsia is most optimally defined as pain or discomfort centred in the upper abdomen. The symptom complex may be caused by peptic ulcer disease, gastro-oesophageal reflux, or gastric cancer but is most often due to functional (or non-ulcer) dyspepsia. While upper endoscopy is the method of choice to determine the underlying cause of dyspepsia, it is expensive. A more pragmatic approach is needed in the Asia-Pacific region where health services are limited. A detailed treatment algorithm is given for managing patients presenting with new-onset dyspepsia and documented functional dyspepsia after endoscopy, and evidence to support this approach is reviewed. Prompt endoscopy is recommended for patients with alarm features. In patients without alarm features, treatment for 2–4 weeks with an empirical anti-secretory or prokinetic agent, followed by investigation using non-invasive Helicobacter pylori testing and treatment for patients who do not respond or relapse, is recommended. Trials of management strategies are now needed to establish the efficacy and cost-effectiveness of the approaches recommended.  相似文献   
105.
106.
107.
108.
This study was conducted on 1359 healthy, non-smoking Turkish children (727M, 632F) with a mean age of 11.7 ± 3.4 (6–17) years, in order to determine the normal values of peak expiratory flow (PEF) in Turkish children and to compare various peak-flow meters (PEFMs). PEF values increased with age and height in boys and girls. The relative increase in boys was significantly higher at puberty (p < 0.01). The values of Turkish children were found to be similar to those of Europeans. The results obtained from the three PEFMs were closely correlated.  相似文献   
109.
110.
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