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   2249篇
  免费   145篇
  国内免费   6篇
耳鼻咽喉   12篇
儿科学   40篇
妇产科学   52篇
基础医学   271篇
口腔科学   56篇
临床医学   297篇
内科学   732篇
皮肤病学   32篇
神经病学   181篇
特种医学   36篇
外科学   160篇
综合类   12篇
预防医学   177篇
眼科学   36篇
药学   158篇
中国医学   3篇
肿瘤学   145篇
  2023年   31篇
  2022年   15篇
  2021年   51篇
  2020年   52篇
  2019年   70篇
  2018年   65篇
  2017年   45篇
  2016年   60篇
  2015年   63篇
  2014年   63篇
  2013年   138篇
  2012年   152篇
  2011年   159篇
  2010年   86篇
  2009年   63篇
  2008年   134篇
  2007年   131篇
  2006年   132篇
  2005年   138篇
  2004年   126篇
  2003年   95篇
  2002年   95篇
  2001年   36篇
  2000年   38篇
  1999年   29篇
  1998年   20篇
  1997年   13篇
  1996年   16篇
  1995年   16篇
  1994年   16篇
  1993年   13篇
  1992年   16篇
  1991年   15篇
  1990年   20篇
  1989年   22篇
  1988年   19篇
  1987年   21篇
  1986年   17篇
  1985年   12篇
  1984年   9篇
  1983年   9篇
  1982年   5篇
  1981年   9篇
  1977年   4篇
  1975年   4篇
  1974年   9篇
  1970年   4篇
  1968年   7篇
  1967年   6篇
  1966年   4篇
排序方式: 共有2400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.
Wound pain is a serious problem for elderly patients suffering from chronic leg ulcers, and it may lead to reduced wound healing rates and reduced quality of life. Biatain-Ibu Non-adhesive (Coloplast A/S), a new pain-reducing moist wound healing dressing containing ibuprofen was tested for pain reduction, safety, and efficacy on 10+2 patients in a single-blinded crossover study against Biatain Non-adhesive (Coloplast A/S). Pain was measured with a Numeric Box Scale before, during, and after dressing change. Quality of life was measured using the World Health Organization-5 Well-Being Index. Dressing moist wound healing properties such as absorption capacity and leakage were tested together with assessment of wound exudate and blood plasma content of ibuprofen. Use of the Biatain-Ibu foam dressing correlated with a decrease in pain intensity scores from 7 in the run-in period to approximately 2.5 in the Biatain-Ibu treatment phase. Quality of life measures were improved which together with the reduced pain could contribute to faster wound healing. The moist wound healing properties of Biatain-Ibu were similar to that of the Biatain Non-adhesive and ulcer size was reduced by 24% during the treatment period. Neither side effects nor systemic plasma concentrations of ibuprofen were observed. These data indicate that Biatain-Ibu could reduce persistent and temporary wound pain, increase Quality of life, was found safe to use, and had excellent moist wound healing properties.  相似文献   
4.
5.
 Lactate/H+ transport kinetics were determined by means of the pH-sensitive probe BCECF in sarcolemmal giant vesicles, obtained from rat skeletal muscle, and related to variations in lactate/H+ transport capacity. Vesicle preparations were made from red and white muscles, mixed muscles, denervated muscles, muscles of old rats and rats that had been subjected to high-intensity training, endurance training, repeated exposure to hypoxia, and hypothyroid or hyperthyroid treatments. The lactate/H+ transport capacity of red muscles was greater than that of white muscles, and this difference was associated with a higher maximal transport rate (V max) in red muscles, whereas the K m was similar in the two muscle types. High-intensity training and hyperthyroidism increased the lactate/H+ transport capacity by enhancing V max without affecting K m. Similarly, a reduced transport capacity with old age and hypothyroidism was due to a decrease in V max. The denervation-induced decline in lactate/H+ transport capacity resulted from both an increased K m and a reduced V max. The present data show that muscle type differences and most changes in the lactate/H+ transport capacity are mediated by modifications in V max, which is expected to represent the number of membrane transporter molecules. K m is unaffected by most treatments and appears to be independent of fibre type. Received: 10 February 1998 / Received after revision: 21 April 1998 / Accepted: 24 April 1998  相似文献   
6.
Aim: Sodium/bicarbonate co‐transport (NBC) has been suggested to have a role in muscle pH regulation. We investigated the presence of NBC proteins in rat and human muscle samples and the fibre type distribution of the identified NBCs. Methods and results: Western blotting of muscle homogenates and sarcolemmal membranes (sarcolemmal giant vesicles) were used to screen for the presence of NBCs. Immunohistochemistry was used for the subcellular localization. The functional test revealed that approximately half of the pH recovery in sarcolemmal vesicles produced from rat muscle is mediated by bicarbonate‐dependent transport. This indicates that the NBCs are preserved in the vesicles. The western blotting experiments demonstrated the existence of at least two NBC proteins in skeletal muscle. One NBC protein (approximately 150 kDa) seems to be related to the kidney/pancreas/heart isoform NBC1, whereas the other protein (approximately 200 kDa) is related to the NBC4 isoform. The two NBC proteins represent the electrogenic isoforms named NBCe1 and NBCe2. Membrane fractionation and immunofluorescence techniques confirmed that the two NBCs are located in the sarcolemmal membrane as well as in some internal membranes, probably the T‐tubules. The two NBCs localized in muscle have distinct fibre type distributions. Conclusions: Skeletal muscle possesses two variants of the sodium/bicarbonate co‐transporter (NBC) isoforms, which have been called NBCe1 and NBCe2.  相似文献   
7.
We have studied asthma mortality in Denmark from 1969 to 1988. Age standardized mortality rates calculated in three age groups, 10-34, 35-59, and greater than or equal to 60 years, disclosed similar trends. Increasing mortality from asthma in the mid-1970s to 1988 was seen in all three age groups with higher mortality in 1979-88 as compared with 1969-78 of 95%, 55%, and 69%, respectively. Since the eighth revision of the International Classification of Diseases (ICD8) was used in Denmark over the entire 20-year period, changes in coding practice due to change of classification system cannot explain the findings.  相似文献   
8.
9.
From 1978 to 1985, 2,465 male bus drivers in the three major cities in Denmark were followed with regard to hospital admission due to myocardial infarction (MI) and death due to ischemic heart disease (IHD). In all 2,045 (83%) of these men responded in 1978 to a questionnaire on psychosocial well-being and work conditions. The respondents did not differ from the nonrespondents regarding hospital admissions and death in the follow-up period (1978-1984). Sixty-two cases of MI were registered among the 2,045 bus drivers in 1978-1984. On this basis relative risk for MI was calculated with a multiple regression model for independent variables regarding psychosocial well-being and work conditions. High work load (driving in heavy traffic) was significantly associated with the occurrence of MI. Of the psychosocial factors "no social contact with colleagues" and "increased work pace" were also significantly associated with the occurrence of MI. Smoking habits tended to be associated with the occurrence of MI, while stress symptoms and job dissatisfaction did not. The mental burden on bus drivers working in heavy traffic seems a possible explanation for the findings.  相似文献   
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