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   33557篇
  免费   2504篇
  国内免费   97篇
耳鼻咽喉   373篇
儿科学   847篇
妇产科学   465篇
基础医学   4374篇
口腔科学   650篇
临床医学   3024篇
内科学   7038篇
皮肤病学   502篇
神经病学   3850篇
特种医学   1378篇
外国民族医学   3篇
外科学   4893篇
综合类   676篇
一般理论   66篇
预防医学   2939篇
眼科学   636篇
药学   2175篇
中国医学   20篇
肿瘤学   2249篇
  2023年   117篇
  2022年   94篇
  2021年   472篇
  2020年   279篇
  2019年   480篇
  2018年   606篇
  2017年   444篇
  2016年   516篇
  2015年   587篇
  2014年   893篇
  2013年   1408篇
  2012年   2136篇
  2011年   2281篇
  2010年   1227篇
  2009年   1150篇
  2008年   2150篇
  2007年   2301篇
  2006年   2259篇
  2005年   2447篇
  2004年   2158篇
  2003年   1977篇
  2002年   2022篇
  2001年   402篇
  2000年   332篇
  1999年   388篇
  1998年   435篇
  1997年   418篇
  1996年   392篇
  1995年   381篇
  1994年   306篇
  1993年   298篇
  1992年   291篇
  1991年   310篇
  1990年   286篇
  1989年   258篇
  1988年   217篇
  1987年   248篇
  1986年   210篇
  1985年   220篇
  1984年   250篇
  1983年   241篇
  1982年   286篇
  1981年   271篇
  1980年   234篇
  1979年   145篇
  1978年   161篇
  1977年   104篇
  1976年   124篇
  1975年   91篇
  1974年   119篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Marie Warrer Petersen  Tine Sylvest Meyhoff  Marie Helleberg  Maj-Brit Nørregaard Kjær  Anders Granholm  Carl Johan Steensen Hjortsø  Thomas Steen Jensen  Morten Hylander Møller  Peter Buhl Hjortrup  Mik Wetterslev  Gitte Kingo Vesterlund  Lene Russell  Vibeke Lind Jørgensen  Klaus Tjelle  Thomas Benfield  Charlotte Suppli Ulrik  Anne Sofie Andreasen  Thomas Mohr  Morten H. Bestle  Lone Musaeus Poulsen  Mette Friberg Hitz  Thomas Hildebrandt  Lene Surland Knudsen  Anders Møller  Christoffer Grant Sølling  Anne Craveiro Brøchner  Bodil Steen Rasmussen  Henrik Nielsen  Steffen Christensen  Thomas Strøm  Maria Cronhjort  Rebecka Rubenson Wahlin  Stephan Jakob  Luca Cioccari  Balasubramanian Venkatesh  Naomi Hammond  Vivekanand Jha  Sheila Nainan Myatra  Christian Gluud  Theis Lange  Anders Perner 《Acta anaesthesiologica Scandinavica》2020,64(9):1365-1375

Introduction

Severe acute respiratory syndrome coronavirus-2 has caused a pandemic of coronavirus disease (COVID-19) with many patients developing hypoxic respiratory failure. Corticosteroids reduce the time on mechanical ventilation, length of stay in the intensive care unit and potentially also mortality in similar patient populations. However, corticosteroids have undesirable effects, including longer time to viral clearance. Clinical equipoise on the use of corticosteroids for COVID-19 exists.

Methods

The COVID STEROID trial is an international, randomised, stratified, blinded clinical trial. We will allocate 1000 adult patients with COVID-19 receiving ≥10 L/min of oxygen or on mechanical ventilation to intravenous hydrocortisone 200 mg daily vs placebo (0.9% saline) for 7 days. The primary outcome is days alive without life support (ie mechanical ventilation, circulatory support, and renal replacement therapy) at day 28. Secondary outcomes are serious adverse reactions at day 14; days alive without life support at day 90; days alive and out of hospital at day 90; all-cause mortality at day 28, day 90, and 1 year; and health-related quality of life at 1 year. We will conduct the statistical analyses according to this protocol, including interim analyses for every 250 patients followed for 28 days. The primary outcome will be compared using the Kryger Jensen and Lange test in the intention to treat population and reported as differences in means and medians with 95% confidence intervals.

Discussion

The COVID STEROID trial will provide important evidence to guide the use of corticosteroids in COVID-19 and severe hypoxia.
  相似文献   
3.
4.
5.
6.
7.

Background  

There are no published utilities for the post-anesthesia state obtained by the standard gamble method (SG).  相似文献   
8.
9.
OBJECTIVE: Neighborhood sociodemographic characteristics may be important to the mental health of older adults who have decreased mobility and fewer resources. Our objective was to examine the association between neighborhood context and level of depressive symptomatology in older adults in a diverse geographic region of central North Carolina. METHODS: The sample included 2,998 adults 65 or older residing in 91 census tracts. Depressive symptoms were measured using the Center for Epidemiologic Studies-Depression scale (CES-D). Neighborhoods were characterized by five census-based characteristics: socioeconomic disadvantage, socioeconomic advantage, racial/ethnic heterogeneity, residential stability, and age structure. RESULTS: In ecologic level analyses, level of census tract socioeconomic disadvantage was associated with increased depressive symptoms. To determine whether neighborhood context was associated with depressive symptoms independently of individual characteristics, the authors used multilevel modeling. The authors examined the ability of each of five neighborhood (level 2) characteristics to predict a level 1 outcome (CES-D symptoms) controlling for the effects of individual (level 1) characteristics. Younger age, being widowed, lower income, and having some functional limitations were associated with increased depression symptoms conditional on census tract random effects. However, none of the neighborhood characteristics was significantly associated with depression symptoms, conditional on census tract random effects, either unadjusted or adjusted for individual characteristics. CONCLUSION: Any observed association between neighborhood sociodemographic characteristics and individual depressive symptoms in our sample may reflect the characteristics of the individuals who reside in the neighborhood rather than the neighborhood characteristics themselves. The use of multilevel modeling is important to separate these effects.  相似文献   
10.
This paper is a comprehensive review on the effect of bandaging, bracing, and neoprene sleeves on knee proprioception following anterior cruciate ligament (ACL) injury and reconstruction with a focus on studies that have measured joint position sense and threshold to detection of passive knee motion. Disruption of the ACL does not appear to alter joint position sense soon after injury, although there is evidence that in some subjects deterioration may occur over time. An ACL tear creates a deficit in the threshold to detection of passive knee motion soon after injury and in those with chronic tears. The magnitude of worsening is less then 1.0 degree of movement in flexion-extension and of questionable concern from a clinical and functional perspective. Application of a functional brace or neoprene sleeve to the ACL-deficient limb does not improve the threshold to detection of passive knee motion; however, application of an elastic bandage to a knee with an ACL tear improves joint position sense. Reconstruction of a torn ACL is associated with a deficit in the threshold to detection of passive knee motion, and during the first year of healing the use of a neoprene sleeve provides improvement. Two years following ACL reconstruction there is no deficit in the threshold to detection of passive knee motion and the use of a brace has no effect on this outcome.  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