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   274413篇
  免费   7171篇
  国内免费   630篇
耳鼻咽喉   2124篇
儿科学   9890篇
妇产科学   5345篇
基础医学   30935篇
口腔科学   5372篇
临床医学   21500篇
内科学   53021篇
皮肤病学   3338篇
神经病学   26172篇
特种医学   11140篇
外国民族医学   1篇
外科学   37591篇
综合类   2682篇
一般理论   48篇
预防医学   27818篇
眼科学   4374篇
药学   16563篇
中国医学   1031篇
肿瘤学   23269篇
  2023年   954篇
  2022年   821篇
  2021年   3150篇
  2020年   2289篇
  2019年   3079篇
  2018年   24788篇
  2017年   19571篇
  2016年   22070篇
  2015年   4262篇
  2014年   5252篇
  2013年   6577篇
  2012年   15647篇
  2011年   29768篇
  2010年   23454篇
  2009年   15520篇
  2008年   26397篇
  2007年   28551篇
  2006年   7228篇
  2005年   8379篇
  2004年   8943篇
  2003年   9259篇
  2002年   6908篇
  2001年   764篇
  2000年   734篇
  1999年   659篇
  1998年   792篇
  1997年   699篇
  1996年   496篇
  1995年   540篇
  1994年   511篇
  1993年   404篇
  1992年   320篇
  1991年   269篇
  1990年   310篇
  1989年   255篇
  1988年   220篇
  1987年   180篇
  1986年   175篇
  1985年   137篇
  1984年   147篇
  1983年   144篇
  1982年   178篇
  1981年   111篇
  1980年   161篇
  1979年   76篇
  1978年   83篇
  1977年   70篇
  1976年   64篇
  1974年   72篇
  1932年   63篇
排序方式: 共有10000条查询结果,搜索用时 93 毫秒
41.
42.
Objective: Multiple sclerosis (MS) is associated with prospective memory (PM) deficits, which may increase the risk of poor functional/health outcomes such as medication non-adherence. This study examined the potential benefits of selective reminding to enhance PM functioning in persons with MS.

Method: Twenty-one participants with MS and 22 healthy adults (HA) underwent a neuropsychological battery including a Selective Reminding PM (SRPM) experimental procedure. Participants were randomly assigned to either: (1) a selective reminding condition in which participants learn (to criterion) eight prospective memory tasks in a Selective Reminding format; or (2) a single trial encoding condition (1T).

Results: A significant interaction was demonstrated, with MS participants receiving greater benefit than HAs from the SR procedure in terms of PM performance. Across diagnostic groups, participants in the SR conditions (vs. 1T conditions) demonstrated significantly better PM performance. Individuals with MS were impaired relative to HAs in the 1T condition, but performance was statistically comparable in the SR condition.

Conclusions: This preliminary study suggests that selective reminding can be used to enhance PM cue detection and retrieval in MS. The extent to which selective reminding of PM is effective in naturalistic settings and for health-related behaviours in MS remains to be determined.  相似文献   

43.
44.
45.
46.
47.

Background

Influenza viruses (FLUV) are continuously evolving, which explain the occurrence of seasonal influenza epidemics and the need to review the vaccine strain composition annually. The aim is to describe the genetic diversity and clinical outcomes of FLUV detected at a tertiary university hospital in Barcelona (Spain) during the 2012–2016 seasons.

Methods

The detection of FLUV from patients attended at the Emergency Department or admitted to the hospital was performed by either immunofluorescence or PCR-based assays. A specific real-time one-step multiplex RT-PCR was performed for influenza A (FLUAV) subtyping. The complete coding haemagglutinin domain 1 (HA1) and neuraminidase (NA) (2015–2016) protein sequences from a representative sampling were molecular characterised.

Results

A total 1774 (66.1%) FLUAV and 910 (33.9%) influenza B (FLUBV) cases were laboratory-confirmed. The hospitalisation rate was different between seasons, being the highest (81.4%) during the 2014–2015 season. FLUV were genetically close to vaccine strains except to the 2014–2015, in which most characterised A(H3N2) viruses belonged to a genetic group different from the vaccine strain. During the 2015–2016 season, B/Victoria-like viruses were the most predominant, but this component was not included in the trivalent vaccine used. Mutations D222G or D222N in HA1-domain were found in 3 A(H1N1)pdm09 strains from ICU-admitted cases. Three A(H1N1)pdm09 strains carried the NA H275Y (2) and S247N (1) mutations, respectively related to resistance or decreased susceptibility to oseltamivir.

Conclusions

The circulation of drifted A(H3N2) strains during the 2014–2015 season was related to the high hospitalisation rate due to the mismatch with the vaccine strains. The predominance of a FLUBV lineage not included in the trivalent influenza vaccine during the 2015–2016 season highlights the need to use a tetravalent influenza vaccine. Virological surveillance of viral variants carrying protein changes that alter tropism and susceptibility to antivirals features should be strengthened in hospital settings.  相似文献   
48.
49.
The recognition that neurogenesis does not stop with adolescence has spun off research towards the reduction of brain disorders by enhancing brain regeneration. Adult neurogenesis is one of the tougher problems of developmental biology as it requires the generation of complex intracellular and pericellular anatomies, amidst the danger of neuroinflammation. We here review how a multitude of regulatory pathways optimized for early neurogenesis has to be revamped into a new choreography of time dependencies. Distinct pathways need to be regulated, ranging from neural growth factor induced differentiation to mitochondrial bioenergetics, reactive oxygen metabolism, and apoptosis. Requiring much Gibbs energy consumption, brain depends on aerobic energy metabolism, hence on mitochondrial activity. Mitochondrial fission and fusion, movement and perhaps even mitoptosis, thereby come into play. All these network processes are interlinked and involve a plethora of molecules. We recommend a deep thinking approach to adult neurobiology.  相似文献   
50.
Clinical Rheumatology - The rheumatoid factor (RF) is present in numerous autoimmune disorders, although its role in many of them remains a subject of research. The study assesses the role of RF as...  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