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   48847篇
  免费   3120篇
  国内免费   239篇
耳鼻咽喉   500篇
儿科学   922篇
妇产科学   625篇
基础医学   6387篇
口腔科学   1078篇
临床医学   5142篇
内科学   10802篇
皮肤病学   988篇
神经病学   5613篇
特种医学   2493篇
外科学   8208篇
综合类   296篇
一般理论   13篇
预防医学   2239篇
眼科学   646篇
药学   2952篇
中国医学   69篇
肿瘤学   3233篇
  2023年   408篇
  2022年   561篇
  2021年   1411篇
  2020年   840篇
  2019年   1269篇
  2018年   1438篇
  2017年   1123篇
  2016年   1346篇
  2015年   1557篇
  2014年   1967篇
  2013年   2425篇
  2012年   3896篇
  2011年   3924篇
  2010年   2338篇
  2009年   2101篇
  2008年   3349篇
  2007年   3433篇
  2006年   3169篇
  2005年   3117篇
  2004年   2757篇
  2003年   2637篇
  2002年   2375篇
  2001年   439篇
  2000年   335篇
  1999年   399篇
  1998年   478篇
  1997年   361篇
  1996年   286篇
  1995年   223篇
  1994年   219篇
  1993年   164篇
  1992年   145篇
  1991年   137篇
  1990年   100篇
  1989年   90篇
  1988年   99篇
  1987年   66篇
  1986年   77篇
  1985年   73篇
  1984年   108篇
  1983年   82篇
  1982年   77篇
  1981年   59篇
  1980年   55篇
  1979年   48篇
  1978年   47篇
  1977年   51篇
  1976年   48篇
  1975年   48篇
  1974年   47篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
21.
22.
23.
24.
Clinical Epileptology - Der plötzliche unerwartete Tod stellt eine seltene, aber schwerwiegende Komplikation für Epilepsiepatienten dar. Das Risiko hierfür ist u. a. nachts und...  相似文献   
25.
Neurocritical Care - For years, the use of ketamine as an anesthetic to patients suffering from acute brain injury has been debated because of its possible deleterious effects on the cerebral...  相似文献   
26.
27.
IntroductionPeople with Down syndrome (DS) have high respiratory morbidity, evaluating their respiratory health with standardized, objective tests is desirable. Thus, the objective of this study was to evaluate the technical quality of Pulmonary Function Tests (PFTs) to determine which ones are most suitable for this population.MethodsParticipants included children, teenagers and adults with DS, 5 years of age or older (n = 302). The technical quality of the impulse oscillometry system (IOS), forced spirometry, lung-diffusing capacity for carbon monoxide (DLCO), and 6-min walk test (6MWT) were analyzed by age group. Capnography and pulse oximetry were included in the study. Technical quality was determined on the basis of current international PFTs standards.ResultsFifty-one percent of participants were males. A total of 184 participants (71%) who completed the IOS fulfilled the quality criteria, while 210 (70%) completed the 6MWT. Performance on forced spirometry and DLCO was poor. All pulse oximetries and 96% percent heart rates obtained had good quality, but exhaled carbon dioxide (PetCO2) and respiratory rate (RR) showed deficient repeatability.ConclusionsIOS appears to be the most reliable instrument for evaluating lung mechanics in individuals with DS.  相似文献   
28.
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   
29.
Fine‐needle aspiration cytology using a novel ultrasound needle guidance system on the basis of standard needle magnetization was consecutively performed in 30 (15 in‐plane and 15 out‐of‐plane) suspicious thyroid nodules. Nondedicated, commercially available needles were used. The technical effectiveness and safety of the system were satisfying; system failures were observed in 2 cases. The needle tip could be (at least occasionally) visualized inside the thyroid nodule in 96%, and the subjective procedure ratings were excellent in 57%. The out‐of‐plane technique was significantly superior in both respects (P = .021 and .027, respectively). Standard needle magnetization ultrasound needle guidance was easy to apply and cost‐effective and has the potential to improve fine‐needle aspiration cytology performance.  相似文献   
30.
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