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   9274篇
  免费   665篇
  国内免费   21篇
耳鼻咽喉   94篇
儿科学   277篇
妇产科学   242篇
基础医学   1370篇
口腔科学   189篇
临床医学   968篇
内科学   1840篇
皮肤病学   222篇
神经病学   872篇
特种医学   301篇
外科学   1019篇
综合类   93篇
一般理论   12篇
预防医学   858篇
眼科学   150篇
药学   600篇
中国医学   9篇
肿瘤学   844篇
  2023年   108篇
  2022年   80篇
  2021年   336篇
  2020年   238篇
  2019年   301篇
  2018年   304篇
  2017年   264篇
  2016年   283篇
  2015年   276篇
  2014年   363篇
  2013年   506篇
  2012年   719篇
  2011年   677篇
  2010年   341篇
  2009年   360篇
  2008年   543篇
  2007年   553篇
  2006年   488篇
  2005年   483篇
  2004年   403篇
  2003年   355篇
  2002年   355篇
  2001年   136篇
  2000年   98篇
  1999年   111篇
  1998年   65篇
  1997年   35篇
  1996年   42篇
  1995年   36篇
  1994年   48篇
  1993年   45篇
  1992年   78篇
  1991年   71篇
  1990年   64篇
  1989年   67篇
  1988年   68篇
  1987年   62篇
  1986年   50篇
  1985年   55篇
  1984年   32篇
  1983年   29篇
  1981年   28篇
  1980年   22篇
  1979年   25篇
  1977年   23篇
  1976年   21篇
  1974年   21篇
  1973年   21篇
  1971年   20篇
  1969年   29篇
排序方式: 共有9960条查询结果,搜索用时 45 毫秒
1.
Collagens are the most abundant proteins in the extracellular matrix. They provide a framework to build organs and tissues and give structural support to make them resistant to mechanical load and forces. Several intra‐ and extracellular modifications are needed to make functional collagen molecules, intracellular post‐translational modifications of proline and lysine residues having key roles in this. In this article, we provide a review on the enzymes responsible for the proline and lysine modifications, that is collagen prolyl 4‐hydroxylases, 3‐hydroxylases and lysyl hydroxylases, and discuss their biological functions and involvement in diseases.  相似文献   
2.
3.
4.
Background: Physicians have long had patients whom they have labeled “difficult”, but little is known about how medical students perceive difficult encounters with patients.

Methods: In this study, we analyzed 134 third year medical students’ reflective essays written over an 18-month period about difficult student–patient encounters. We used a qualitative computerized software program, Atlas.ti to analyze students’ observations and reflections.

Results: Main findings include that students described patients who were angry and upset; noncompliant with treatment plans; discussed “nonmedical” problems; fearful, worried, withdrawn, or “disinterested” in their health. Students often described themselves as anxious, uncertain, confused, and frustrated. Nevertheless, they saw themselves behaving in empathic and patient-centered ways while also taking refuge in “standard” behaviors not necessarily appropriate to the circumstances. Students rarely mentioned receiving guidance from attendings regarding how to manage these challenging interactions.

Conclusions: These third-year medical students recognized the importance of behaving empathically in difficult situations and often did so. However, they often felt overwhelmed and frustrated, resorting to more reductive behaviors that did not match the needs of the patient. Students need more guidance from attending physicians in order to approach difficult interactions with specific problem-solving skills while maintaining an empathic, patient-centered context.  相似文献   
5.
6.
7.
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   
8.
9.
10.
A 72-year-old man presented with a short duration of symptoms relating to a right fronto-parietal glioblastoma and a family history of children with brain tumours. Analysis of the patient's family tree revealed that out of seven children, he had a living son with anaplastic astrocytoma, a daughter who had died with a glioblastoma, and a son who had died with a histologically undiagnosed intrinsic brain tumour. One niece was also thought to have died from a brain tumour. All of the other affected family members had onset in their third or fourth decades. Tissue was only available from two of the affected individuals, precluding familial genetic analysis at this stage. There is no clinical evidence to support a diagnosis of a multiple cancer or neurocutaneous syndrome in this family. In view of what is known about the genetics of familial glioma, it is interesting to note the clinical evidence of both 'primary' glioblastoma and anaplastic astrocytoma in the same kindred.  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