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   11911篇
  免费   1109篇
  国内免费   98篇
耳鼻咽喉   34篇
儿科学   347篇
妇产科学   115篇
基础医学   707篇
口腔科学   170篇
临床医学   2384篇
内科学   1116篇
皮肤病学   64篇
神经病学   1312篇
特种医学   101篇
外科学   520篇
综合类   1011篇
一般理论   15篇
预防医学   4153篇
眼科学   19篇
药学   642篇
  2篇
中国医学   152篇
肿瘤学   254篇
  2024年   8篇
  2023年   246篇
  2022年   271篇
  2021年   512篇
  2020年   654篇
  2019年   541篇
  2018年   566篇
  2017年   497篇
  2016年   498篇
  2015年   494篇
  2014年   773篇
  2013年   1031篇
  2012年   677篇
  2011年   800篇
  2010年   607篇
  2009年   608篇
  2008年   545篇
  2007年   577篇
  2006年   475篇
  2005年   372篇
  2004年   367篇
  2003年   300篇
  2002年   274篇
  2001年   264篇
  2000年   184篇
  1999年   155篇
  1998年   108篇
  1997年   119篇
  1996年   83篇
  1995年   61篇
  1994年   54篇
  1993年   52篇
  1992年   40篇
  1991年   33篇
  1990年   37篇
  1989年   22篇
  1988年   36篇
  1987年   15篇
  1986年   29篇
  1985年   25篇
  1984年   25篇
  1983年   11篇
  1982年   12篇
  1981年   17篇
  1980年   8篇
  1979年   8篇
  1978年   4篇
  1977年   8篇
  1976年   8篇
  1974年   4篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.
7.

Objective

The aim of the study was to estimate the effect of the state-based reinsurance programs through the section 1332 State Innovation Waivers on health insurance marketplace premiums and insurer participation.

Data Source

2015 to 2022 Robert Wood Johnson Foundation Health Insurance Exchange Compare Datasets.

Study Design

An event study difference-in-differences (DD) model separately for each year of implementation and a synthetic control method (SCM) are used to estimate year-by-year effects following program implementation.

Data Collection/Extraction Methods

Not applicable.

Principal Findings

Reinsurance programs were associated with a decline in premiums in the first year of implementation by 10%–13%, 5%–19%, and 11%–17% for bronze, silver, and gold plans (p < 0.05). There is a trend of sustained declines especially for states that implemented their programs in 2019 and 2020. The SCM analyses suggest some effect heterogeneity across states but also premium declines across most states. There is no evidence that reinsurance programs affected insurer participation.

Conclusion

State-based reinsurance programs have the potential to improve the affordability of health insurance coverage. However, reinsurance programs do not appear to have had an effect on insurer participation, highlighting the need for policy makers to consider complementary strategies to encourage insurer participation.  相似文献   
8.

Background

Weaning from mechanical ventilation and tracheostomy after prolonged intensive care consume enormous resources with optimal management not currently well described. Restoration of respiratory flow via the upper airway is essential and early cuff-deflation using a one-way valve (OWV) is recommended. However, extended OWV use may cause dry airways and thickened secretions which challenge the weaning process. High-flow therapy via the tracheostomy tube (HFT-T) humidifies inspired air and may be connected via an in-line OWV (HFT-T-OWV) alleviating these problems. We aim to provide clinical and experimental data on the safety of HFT-T-OWV along with a practical guide to facilitate clinical use during weaning from mechanical ventilation and tracheostomy.

Methods

Data on adverse events of HFT-T-OWV were retrieved from a quality register for patients treated at an intensive care rehabilitation center between 2019 and 2022. Benchtop experiments were performed to measure maximum pressures and pressure support generated by HFT-T-OWV at 25–60 L/min flow using two different HFT-T adapters (interfaces). In simulated airway obstruction using a standard OWV (not in-line) maximum pressures were measured with oxygen delivered via the side port at 1–3 L/min.

Results

Of 128 tracheostomized patients who underwent weaning attempts, 124 were treated with HFT-T-OWV. The therapy was well tolerated, and no adverse events related to the practice were detected. The main reason for not using HFT-T-OWV was partial upper airway obstruction using a OWV. Benchtop experiments demonstrated HFT-T-OWV maximum pressures <4 cmH2O and pressure support 0–0.6 cmH2O. In contrast, 1–3 L/min supplemental oxygen via a standard OWV caused pressures between 84 and 148 cmH2O during simulated airway obstruction.

Conclusions

Current study clinical data and benchtop experiments indicate that HFT-T-OWV was well tolerated and appeared safe. Pressure support was low, but humidification may enable extended use of a OWV without dry airway mucosa and thickened secretions. Results suggest the treatment could offer advantages to standard OWV use, with or without supplementary oxygen, as well as to HFT-T without a OWV, for weaning from mechanical ventilation and tracheostomy. However, for definitive treatment recommendations, randomized clinical trials are needed.  相似文献   
9.

Introduction

Left ventricular (LV) dysfunction is estimated to occur in 10%–25% of the general intensive care unit (ICU) population and is frequently seen as regional wall motion abnormalities (RWMAs). Although RWMA is mostly attributed to myocardial ischemia or infarction, some studies have suggested that nonischemic RWMA might also be prevalent. We sought to establish that RWMA can be seen in critically ill patients with normal coronary arteries and to explore reasons for RWMA in this population.

Methods

In this retrospective study, data from the hospital angiography register and the ICU register were collated between 2012 and 2019. Patients were identified who underwent angiography in conjunction with their ICU stay and had RWMA on echocardiography. Patients were divided into either those with non-obstructed or those with obstructed coronary arteries. Cardiac magnetic resonance imaging (cMRI) examinations were reviewed if they had been performed on patients with non-obstructed coronaries.

Results

We identified 53 patients with RWMA and non-obstructed coronary arteries and 204 patients with RWMA and obstructed coronary arteries. Patients with non-obstructed coronary arteries were more often female, younger, and had fewer cardiovascular risk factors. They less commonly had ST elevation, but more frequently had T-wave inversion or serious arrhythmias. Troponin levels were higher in patients with obstructed coronary arteries, but NT-proBNP was similar between the groups. There were no differences in risk-adjusted 90-day mortality between patients with non-obstructed versus obstructed coronary arteries (OR 1.21, [95% CI 0.56–2.64], p = .628). In those with non-obstructed coronary arteries, follow-up echocardiography was available for 38 patients, of whom 30 showed normalization of cardiac function. Of the 14 patients with non-obstructed coronary arteries on whom cMRI was performed, 7 had a tentative diagnosis of Takotsubo syndrome or myocardial stunning; 4 had a myocardial infarction (preexisting in 3 cases); 1 patient had acute myocarditis; 1 patient had post-myocarditis; and 1 patient was diagnosed with dilated cardiomyopathy.

Conclusion

RWMA can be seen to occur in critically ill patients in the absence of coronary artery obstruction. Several conditions can cause regional hypokinesia, and cMRI is useful to evaluate the underlying etiology.  相似文献   
10.
新型冠状病毒肺炎(NCP)是一种具有广泛传染、较强致病性的外感疫病,对公众健康造成极大威胁[1-2]。由于病邪侵入人体后传变迅速,疫毒易于弥漫三焦、充斥表里转为危重症,处于危重症时现代医学目前只能对症支持治疗,为恢复危重症患者脏器机能、改善危重症状,配合中医药辨证施治值得深入思考。现以中医整体辨证的视角对新型冠状病毒肺炎所致危重病症辨证梳理,为临床提供一定的借鉴。  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