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   485篇
  免费   17篇
  国内免费   31篇
耳鼻咽喉   4篇
儿科学   27篇
妇产科学   5篇
基础医学   29篇
口腔科学   12篇
临床医学   49篇
内科学   95篇
皮肤病学   15篇
神经病学   24篇
特种医学   54篇
外科学   75篇
综合类   59篇
预防医学   16篇
眼科学   2篇
药学   39篇
肿瘤学   28篇
  2024年   3篇
  2023年   3篇
  2022年   4篇
  2021年   7篇
  2020年   1篇
  2019年   2篇
  2018年   1篇
  2016年   4篇
  2015年   9篇
  2014年   11篇
  2013年   11篇
  2012年   11篇
  2011年   11篇
  2010年   19篇
  2009年   19篇
  2008年   20篇
  2007年   23篇
  2006年   27篇
  2005年   17篇
  2004年   15篇
  2003年   7篇
  2002年   13篇
  2001年   10篇
  2000年   9篇
  1999年   8篇
  1998年   30篇
  1997年   36篇
  1996年   30篇
  1995年   23篇
  1994年   13篇
  1993年   18篇
  1992年   6篇
  1991年   2篇
  1990年   9篇
  1989年   15篇
  1988年   9篇
  1987年   15篇
  1986年   6篇
  1985年   13篇
  1984年   5篇
  1983年   7篇
  1982年   9篇
  1981年   8篇
  1980年   3篇
  1979年   1篇
  1978年   4篇
  1977年   2篇
  1975年   3篇
  1970年   1篇
排序方式: 共有533条查询结果,搜索用时 31 毫秒
111.
Wavelength discrimination was studied on three colour-normal human observers for open viewing and for reduced time viewing. All three observers show a loss of blue-green wavelength discrimination when viewing time is reduced to 3.75 msec. This loss is shown to be an effect of viewing time alone and not of reduced retinal illuminance. The results confirm those reported by Foster, Scase and Taylor1 although the target size and methodology are different.  相似文献   
112.
Abstract: Some of the issues related to the doubts and complexities involved in the diagnosis and treatment of attention deficit hyperactivity disorder (ADHD) are reviewed. While some writers claim that it is clear that all children presenting with ADHD should be treated by pharmacological means, there are associated risks and politics. However, in the absence of well established and research-supported alternative understandings of the aetiology and treatment of the disorder, many practitioners feel unable to offer a useful service. Resulting frustrations have led some parents to form their own support networks, which make strong demands for increased services. More creative and innovative therapeutic interventions focusing on the broader impact of ADHD must be developed to deal with this disorder.  相似文献   
113.
PURPOSE: Describe the diagnosis, clinical features, pathophysiology, treatment and anesthetic management of amniotic fluid embolism (AFE) in a patient undergoing second trimester pregnancy termination. CLINICAL FEATURES: A 30-yr-old gravida 2, para 1, woman was admitted for a dilatation and evacuation procedure for underlying intra-uterine fetal demise in her second trimester of pregnancy. Hypotension, shock, respiratory arrest, pulseless electrical activity, hemorrhage, disseminated intravascular coagulopathy, requiring cardiopulmonary resuscitation and blood transfusion complicated her intraoperative care. AFE was considered the most likely cause of this intraoperative event. CONCLUSIONS: It is now recognized that the pathophysiological features of AFE are similar to a type-1 hypersensitivity reaction ranging from mild systemic reaction to anaphylaxis and shock. AFE has a high maternal and fetal morbidity and mortality rate, requiring prompt recognition and treatment. In patients with cardiovascular instability, the treatment of AFE is similar to anaphylaxis requiring aggressive fluid hydration, cardiopulmonary resuscitation, administration of blood products and the use of vasopressors.  相似文献   
114.
115.
116.
Objectives/Hypothesis To discover unique genes specific for squamous cell carcinoma of the head and neck for eventual development as tumor markers and vaccine candidates. Study Design Molecular biological analysis of fresh‐frozen head and neck squamous cell cancer (HNSCC). Methods A subtractive library was made from two HNSCC and six normal tissues using a polymerase chain reaction (PCR)–based approach. Genes from this library were PCR amplified and placed on a microarray glass slide. RNA was prepared or obtained from 16 fresh‐frozen HNSCC and 22 normal tissue sources. Fluorescent probes were made from the polyA+ RNA derived from the tumor and normal tissues. The probes were hybridized to the glass slides and excited by a tuneable laser. One hundred seven of the genes showing the highest differential fluorescence value between tumor and normal tissue were identified by sequence analysis. Results Thirteen independent genes were found to be overexpressed in tumor tissues. Of these, nine were previously known: keratins K6 and K16, laminin‐5, plakophilin‐1, matrix metalloproteinase‐2 (MMP), vascular endothelial growth factor, connexin 26, 14–3‐3 sigma, and CaN19. The level of polyA+ RNA of these genes in the tumors was significantly different from the levels in normal tissue (P < .05). Four previously unidentified genes were also discovered to have increased expression in tumor tissue. Comparing the total tumor group (n = 16) to the normal group (n = 22), only one of these genes showed significant overexpression. Conclusion We report the identification of nine known genes that are significantly overexpressed in HNSCC as compared to normal tissue using subtractive and microarray technology. In addition, we present four previously unidentified genes that are overexpressed in a subset of tumors. These genes will be developed as tumor markers and vaccine candidates.  相似文献   
117.
Journal of Community Health - Public health crises require individuals, often volunteers, to help minimize disasters. The COVID-19 pandemic required such activation of individuals, but little is...  相似文献   
118.
119.
Muitidrug resistant tuberculosis has shown an alarming increase and this assumes added importance in view of the increasing number of HIV infected patients. This article reviews the biomechanism of resistance and discusses the present stategies that are available and recommended to tackle the rising incidence of tuberculosis due to resistant mycobacteria.KEYWORDS: Antitubereular drugs, Drug resistance, Mycobacterium tuberculosis  相似文献   
120.
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