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   2315篇
  免费   191篇
  国内免费   15篇
耳鼻咽喉   55篇
儿科学   112篇
妇产科学   97篇
基础医学   283篇
口腔科学   49篇
临床医学   293篇
内科学   339篇
皮肤病学   19篇
神经病学   182篇
特种医学   220篇
外科学   285篇
综合类   97篇
一般理论   1篇
预防医学   176篇
眼科学   25篇
药学   173篇
中国医学   3篇
肿瘤学   112篇
  2021年   17篇
  2020年   22篇
  2019年   19篇
  2018年   14篇
  2017年   31篇
  2016年   26篇
  2015年   32篇
  2014年   48篇
  2013年   71篇
  2012年   64篇
  2011年   62篇
  2010年   57篇
  2009年   62篇
  2008年   61篇
  2007年   91篇
  2006年   70篇
  2005年   69篇
  2004年   81篇
  2003年   82篇
  2002年   83篇
  2001年   80篇
  2000年   88篇
  1999年   75篇
  1998年   63篇
  1997年   64篇
  1996年   57篇
  1995年   51篇
  1994年   37篇
  1993年   40篇
  1992年   48篇
  1991年   71篇
  1990年   68篇
  1989年   63篇
  1988年   70篇
  1987年   64篇
  1986年   47篇
  1985年   54篇
  1984年   37篇
  1983年   21篇
  1982年   28篇
  1981年   27篇
  1980年   26篇
  1979年   31篇
  1978年   33篇
  1977年   38篇
  1976年   28篇
  1975年   20篇
  1974年   15篇
  1972年   13篇
  1967年   10篇
排序方式: 共有2521条查询结果,搜索用时 15 毫秒
41.
42.
43.
Purpose: The purpose of this study was to assess the sensitivity and responsiveness of the Segmental Assessment of Trunk Control (SATCo) for evaluating trunk control in children with spinal cord injury (SCI) receiving activity-based locomotor training (AB-LT).

Methods: Prospective study of nine outcomes for consecutively enrolled children in outpatient AB-LT. To evaluate sensitivity to change, linear-mixed models were constructed and adjusted for covariates: age at and time since SCI. To evaluate responsiveness, standardized response means and 95% confidence intervals were estimated per outcome.

Results: SATCo scores increased significantly (p < 0.05) regardless of chronicity, initial score, and injury level. The SATCo was the most responsive measure and the only outcome demonstrating a large effect size after 3 months of therapy.

Conclusions: Children with SCI receiving AB-LT improved trunk control regardless of chronicity, initial impairment, or prior experience. SATCo sensitivity and responsiveness support its usefulness in measuring trunk control in children with SCI.  相似文献   

44.
45.
In a double blind placebo controlled trial, 434 patients with suspected myocardial infarction were randomised to treatment with nifedipine (n = 217) or placebo (n = 217) within six hours from the onset of chest pain. During the treatment period of 48 hours, a 10 mg capsule containing nifedipine or placebo was given sublingually every four hours for 24 hours, then orally every four hours for the next 24 hours. Acute myocardial infarction was confirmed in 295 patients (146 in the nifedipine group and 149 in the placebo group). The median delay time to intervention with nifedipine in patients with acute myocardial infarction was 111 minutes. Infarct size was assessed by the estimation of release of creatine kinase isoenzyme MB and creatine kinase from blood samples taken every four hours for 48 hours. The total mean (SEM) creatine kinase MB released was 406.4 (27.2) IU/l in the nifedipine group and 345.7 (20.5) IU/l in the placebo group. Total mean (SEM) creatine kinase released was 2749.6 (165.1) IU/l in the nifedipine group and 2698.4 (145.9) IU/l in the placebo group. In hospital mortality was similar for both the nifedipine and placebo groups (6.6% and 5.8% respectively). Treatment with nifedipine in the early phase of acute myocardial infarction seems to have no effect on enzymatically measured infarct size.  相似文献   
46.
OBJECTIVE: To assess current practice in the pharmaceutical industry for assessing the potential for QT interval prolongation by non-cardiovascular medicinal products. METHODS: The survey was based on responses from the Toxicology and (Safety) Pharmacology laboratories (a total of 74 laboratories) of 54 companies based in Europe, Japan/Asia and the USA, received between January and March 1999. RESULTS: All 54 companies conducted preclinical in vivo electrocardiography (EGG) evaluation of new active substances (NASs). Thirty of these companies also conducted in vitro cardiac electrophysiology studies on their compounds. The majority of in vivo work was done in conscious beagle dogs. There was no consistency within the industry in defining the magnitude of change in QT interval that is considered biologically important. Most companies considered a change greater than 10% to be important, although the design of the studies suggested that group sizes used may not give sufficient statistical power to detect this size of change. Bazett's formula was used by 41% of laboratories to correct QT for changes in heart rate, despite the fact that this formula is generally deemed to be unsuitable for use in dogs. For studies in anaesthetised dogs, the majority of laboratories used barbiturate anaesthesia, but researchers should be aware of the effects of this and some other anaesthetic agents on QT interval. As for in vitro cardiac electrophysiology, there was wide diversity in the testing methodologies, particularly with regard to the test species and tissue type. As with QT prolongation, there was no consensus on the degree of action potential prolongation to cause concern. For both in vitro and in vivo testing, the majority of companies tested a minimum of three dose (or concentration) levels in order to ascertain any dose-response relationship. CONCLUSIONS: The survey provides a snapshot of the practice in the industry prior to any internationally-agreed consensus on the most effective and efficient approaches to minimising the risk of QT prolongation by new drugs in man. It must be stated that for any given methodology, the 'majority view' in the industry is not necessarily best practice.  相似文献   
47.
48.
Hemostatic defects in dysproteinemias   总被引:7,自引:0,他引:7  
  相似文献   
49.
Hemoptysis is an unusual complication of flow-directed (Swan-Ganz) catheters. Over-inflation of the balloon with a shearing-induced rupture of a small pulmonary artery, and the spear effect of the catheter tip appear to be the mechanisms in the two cases presented. Diligent care to avoid overinflation of the balloon in the pulmonary capillary wedge position by observation of the pressure waveform is critical. The spear effect that is frequently seen during insertion may be eliminated by deflating the balloon at the first appearance of the pulmonary artery waveform and gradual advancement of the catheter five to eight cm, when the balloon is then reinflated to obtain the wedge.  相似文献   
50.
Psychiatric Quarterly - Both healthcare workers (HCWs) and psychiatric patients during the COVID-19 pandemic appear to have elevated prevalence of psychiatric symptoms, but little is known about...  相似文献   
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