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   1789篇
  免费   108篇
  国内免费   11篇
耳鼻咽喉   5篇
儿科学   45篇
妇产科学   47篇
基础医学   256篇
口腔科学   46篇
临床医学   165篇
内科学   341篇
皮肤病学   155篇
神经病学   94篇
特种医学   200篇
外科学   251篇
综合类   38篇
预防医学   86篇
眼科学   27篇
药学   89篇
中国医学   7篇
肿瘤学   56篇
  2023年   10篇
  2022年   9篇
  2021年   17篇
  2020年   9篇
  2019年   26篇
  2018年   29篇
  2017年   23篇
  2016年   35篇
  2015年   71篇
  2014年   49篇
  2013年   61篇
  2012年   62篇
  2011年   79篇
  2010年   60篇
  2009年   64篇
  2008年   72篇
  2007年   65篇
  2006年   61篇
  2005年   70篇
  2004年   44篇
  2003年   61篇
  2002年   44篇
  2001年   49篇
  2000年   40篇
  1999年   41篇
  1998年   32篇
  1997年   58篇
  1996年   43篇
  1995年   35篇
  1994年   31篇
  1993年   33篇
  1992年   31篇
  1991年   38篇
  1990年   32篇
  1989年   54篇
  1988年   43篇
  1987年   50篇
  1986年   44篇
  1985年   34篇
  1984年   23篇
  1983年   14篇
  1982年   19篇
  1981年   15篇
  1980年   10篇
  1979年   18篇
  1978年   8篇
  1977年   13篇
  1976年   10篇
  1974年   8篇
  1973年   12篇
排序方式: 共有1908条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
This paper describes the implementation of an ultraviolet (UV) laser (Spectra Physics 171-18 with 3 lines: 334, 351 and 364 nm in UV) as light source for fluorescence confocal scanning microscopy. With this instrument it is possible to use fluorophores not previously available for confocal laser microscopical imaging of fluorophores such as fluoro-gold and AMCA. In the study we show confocal laser microscopical imaging of fluorescent motoneurons labelled by retrograde transport of fluoro-gold and AMCA-fluorescent axon terminals labelled with antisera against immunogenes as thyrotropin-releasing hormone (TRH) and calcitonin gene-related peptide (CGRP). These two fluorophores may be recorded simultaneously or separately by using a filter that suppresses the emission of one of the fluorophores. The described instrument should also be useful in applications involving detection of monoamines by the Falck-Hillarp technique, as well as measurements of cytosolic free calcium by indicators such as Fura-2 and Indo-1. Measurements performed in reflected and fluorescence light indicated that the resolution along the optical axis improved by about 25% when UV (351 nm) is used instead of visible light (514 nm). This figure is close to that expected on theoretical basis. There are, however, also serious problems related to the use of UV excitation. Firstly, objectives must be selected based on their UV transmission properties. Secondly, chromatic aberration may cause a substantial focal shift between illuminating and emitted light, calling for a flexible instrumental design in order to allow for compensation. As shown here, this problem can be circumvented by using reflecting objectives but at a price of lower resolution compared with high-aperture refracting objectives.  相似文献   
5.
A synchronous occurrence of large bowel adenocarcinoma and extragenital malignant mixed mesodermal tumour (MMMT) is reported. This case represents the sixth extragenital MMMT reported in the literature.  相似文献   
6.
7.
8.
Zusammenfassung Die Teilnahme der Bundeswehr an internationalen Missionen erfordert ein an die Bedingungen militärischer Einsätze angepasstes Konzept zur intensivmedizinischen Repatriierung. Die umfassende Transportkapazität des auf den Airbus A-310 gestützten Systems von bis zu 44 liegenden Patienten bedingte bereits mehrfach den Einsatz im Rahmen ziviler Großschadensereignisse. Der Transport der häufig vital gefährdeten Patienten erfordert sowohl eine dem Inlandsstandard anzupassende medizintechnische Ausstattung der Luftfahrzeuge als auch entsprechend qualifiziertes medizinisches Begleitpersonal, das aufgrund der Sitzplätze zahlenmäßig begrenzt ist. Dieser Umstand verlangt vom Personal Umsicht bei der Betreuung von zeitgleich mehreren Patienten sowie Befähigung zum eigenständigen Arbeiten. Die Patienten-Transport-Einheiten (PTE) entsprechen in der technischen Ausstattung dem Intensivbehandlungsplatz einer modernen Klinik und gewährleisten auch über eine längere Transportzeit eine Intensivtherapie auf höchstem Niveau. Die Arbeit mit dieser Ausrüstung, die Besonderheiten des Langstreckenlufttransportes und die spezielle Situation des militärischen Einsatzes stellen zusätzliche Anforderungen an das Personal. Um dem gerecht zu werden, erfolgt, ergänzend zur täglichen Arbeit im Rettungsdienst, in den Notaufnahmen und auf den Intensivstationen der Bundeswehrkrankenhäuser eine spezielle Schulung von Rettungsassistenten und Ärzten am Flugmedizinischen Institut der Luftwaffe.  相似文献   
9.
The clinical history of 1538 HIV positive patients was analyzed on the basis of the new CDC classification system of HIV disease and AIDS. This classification system combines three CD4 cell categories (1, 2, and 3) with three clinical categories (A, B, and C) into nine subgroups AI–C3. We examined the overall survival for all subgroups and the AIDS-free survival for subgroups Al–B3. AIDS-free survival for patients in subgroups Al, A2, and B1 was considerably longer than survival in patients from subgroups A3, B2, and B3 (P < 0.0001). According to these findings, the new CDC classification system could be simplified into three stages, stage I and II comprising the above mentioned six subgroups, and stage III comprising clinical AIDS defining categories C1, C2, and C3. These three stages correspond to different periods in the management of HIV positive patients, i.e., period of observation, period of prophylaxis, and period of treatment.Abbreviations AIDS acquired immunodeficiency syndrome - CDC Centers for Disease Control - HIV Human immunodeficiency virus Correspondence to: E.B. Helm  相似文献   
10.
A survey to determine the status of burn rehabilitation services in the United States was developed and sent to 186 burn treatment facilities. The facilities were divided into four groups based upon number of admissions per year (0 to 80, 81 to 120, 121 to 200, and 200+). Completed surveys were received from 114 facilities. Results indicated that burn facilities of different sizes were consistent with respect to the severity of burn injuries treated, the length of hospitalization for acute injuries, and the duration of physician follow-up after discharge. Burn facilities with more admissions were more likely to report (1) organized outpatient burn rehabilitation programs, (2) available specialized burn rehabilitation personnel, (3) regular interdisciplinary inpatient staffing conferences and outpatient clinics, and (4) structured educational activities for staff and Full-time equivalent burn rehabilitation personnel were equally represented across facilities of different sizes. The overall results suggest that there have been substantial improvements in the comprehensiveness of burn rehabilitation care since a previous survey in 1983. Minimum guidelines for burn rehabilitation are suggested based upon the relative consistency between burn facilities indicated by the survey results.  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