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   1346篇
  免费   98篇
  国内免费   9篇
耳鼻咽喉   2篇
儿科学   47篇
妇产科学   81篇
基础医学   223篇
口腔科学   17篇
临床医学   138篇
内科学   260篇
皮肤病学   11篇
神经病学   95篇
特种医学   100篇
外科学   188篇
综合类   14篇
一般理论   2篇
预防医学   128篇
眼科学   6篇
药学   97篇
肿瘤学   44篇
  2023年   12篇
  2022年   7篇
  2021年   17篇
  2020年   12篇
  2019年   38篇
  2018年   44篇
  2017年   29篇
  2016年   24篇
  2015年   27篇
  2014年   34篇
  2013年   68篇
  2012年   67篇
  2011年   71篇
  2010年   49篇
  2009年   46篇
  2008年   63篇
  2007年   52篇
  2006年   44篇
  2005年   55篇
  2004年   42篇
  2003年   53篇
  2002年   45篇
  2001年   31篇
  2000年   39篇
  1999年   42篇
  1998年   35篇
  1997年   33篇
  1996年   36篇
  1995年   24篇
  1994年   28篇
  1993年   22篇
  1992年   26篇
  1991年   19篇
  1990年   23篇
  1989年   20篇
  1988年   23篇
  1987年   19篇
  1986年   17篇
  1985年   12篇
  1984年   9篇
  1983年   6篇
  1982年   8篇
  1981年   15篇
  1980年   10篇
  1979年   12篇
  1978年   5篇
  1977年   9篇
  1976年   11篇
  1975年   5篇
  1972年   3篇
排序方式: 共有1453条查询结果,搜索用时 31 毫秒
1.

Background

Pump speed optimization in patients implanted with a ventricular assist device represents a major challenge during the follow-up period. We present our findings on whether combined invasive hemodynamic ramp tests and cardiopulmonary exercise testing (CPX) can help optimize patient management.

Methods

Eighteen patients implanted with a HeartMate 3 (HM3) device underwent ramp tests with right heart catheterization (including central venous pressure [CVP], pulmonary artery pressure, pulmonary capillary wedge pressure [PCWP], and blood pressure) and echocardiography. Data were recorded at up to 4 speed settings. Speed changes were in steps of 200 revolutions/min (rpm). Evaluation of functional capacity by CPX was conducted according to the modified Bruce protocol.

Results

Only 30% of patients had normal PCWPs at their original rpm settings. In going from lowest to highest speeds, cardiac output improved by 0.25 ± 0.35 L/min/step (total change, 1.28 ± 0.3 L/min), and PCWP decreased by 1.9 ± 0.73 mm Hg/step (total change, 6 ± 1.6 mm Hg). CVP and systolic blood pressure did not change significantly with rpm. The rpm assessment was adjusted based on test results to achieve CVPs and PCWPs as close to normal limits as possible, which was feasible in all patients. On CPX, all patients demonstrated good performance (peak VO2, 16.8 ± 3.5 mL/kg/min).

Conclusion

Hemodynamic ramp testing provides an objective means of optimizing rpm, and has the potential to provide good exercise tolerance.  相似文献   
2.
3.
Several studies have demonstrated that neuropeptides are present in peptidergic fibres of bronchial tissue. The aim of the present study was to evaluate in vivo the effect of nedocromil sodium (2 x 2 mg) on bronchospasm induced by inhalation of substance P. Six moderate asthmatic patients, mean age 25.17 years, were studied. Airway response was measured as FEV1 and the dose of substance P (using a dose range of 23-736 nmol) producing a 20% decrease in FEV1 (PD20) was calculated from the individual semilogarithmic dose-response curves. Patients were studied on 3 separate days in a randomized, double-blind manner. On the first day a baseline PD20 value was determined. On subsequent days substance P challenge was performed after pretreatment (20 min before challenge) with either placebo or nedocromil sodium. Student's paired t-test and Wilcoxon's test were used for statistical analysis. The results of this study demonstrated that inhalation of substance P causes a dose-dependent bronchoconstriction and that the bronchoconstriction induced by substance P can be prevented by pre-treatment with nedocromil sodium.  相似文献   
4.
5.
6.
Thromboembolism constitutes one of the most dangerous complications during the immediate postoperative period of prosthetic surgery. Pharmacological prophylaxis and mechanical vascular compression are not always sufficient to protect from this surgical complication. In patients at greatest risk for thromboembolism, often with a positive history for pulmonary embolism, temporary vena cava filters may be used to reduce the incidence of vascular and pulmonary complications. However useful, these filters cannot be routinely used in orthopedic surgery. We present our results with the use of Filcard RFO2 vena cava filters in an open, randomized study of 30 patients. Received: 5 November 2001/Accepted: 30 November 2001  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