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   16721篇
  免费   1411篇
  国内免费   50篇
耳鼻咽喉   143篇
儿科学   652篇
妇产科学   723篇
基础医学   2133篇
口腔科学   264篇
临床医学   3411篇
内科学   2656篇
皮肤病学   305篇
神经病学   1707篇
特种医学   294篇
外科学   1167篇
综合类   154篇
现状与发展   1篇
一般理论   37篇
预防医学   2298篇
眼科学   211篇
药学   810篇
中国医学   11篇
肿瘤学   1205篇
  2023年   244篇
  2022年   119篇
  2021年   381篇
  2020年   325篇
  2019年   391篇
  2018年   468篇
  2017年   438篇
  2016年   416篇
  2015年   461篇
  2014年   641篇
  2013年   924篇
  2012年   1156篇
  2011年   1272篇
  2010年   705篇
  2009年   757篇
  2008年   1081篇
  2007年   1038篇
  2006年   1081篇
  2005年   1058篇
  2004年   951篇
  2003年   880篇
  2002年   862篇
  2001年   154篇
  2000年   93篇
  1999年   151篇
  1998年   250篇
  1997年   214篇
  1996年   158篇
  1995年   165篇
  1994年   130篇
  1993年   92篇
  1992年   101篇
  1991年   60篇
  1990年   63篇
  1989年   47篇
  1988年   43篇
  1987年   36篇
  1986年   63篇
  1985年   51篇
  1984年   61篇
  1983年   73篇
  1982年   87篇
  1981年   59篇
  1980年   51篇
  1979年   36篇
  1978年   36篇
  1977年   42篇
  1976年   35篇
  1975年   18篇
  1974年   28篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
In osteoimmunology, osteoclastogenesis is understood in the context of the immune system. Today, the in vitro model for osteoclastogenesis necessitates the addition of recombinant human receptor activator of nuclear factor kappa‐B ligand (RANKL) and macrophage colony‐stimulating factor (M‐CSF). The peripheral joints of patients with rheumatoid arthritis (RA) and spondyloarthritis (SpA) are characterized by an immune‐mediated inflammation that can lead to bone destruction. Here, we evaluate spontaneous in vitro osteoclastogenesis in cultures of synovial fluid mononuclear cells (SFMCs) activated only in vivo. SFMCs were isolated and cultured for 21 days at 0.5–1.0 × 106 cells/mL in culture medium. SFMCs and healthy control peripheral blood monocytes were cultured with RANKL and M‐CSF as controls. Tartrate‐resistant acid phosphatase (TRAP) positive multinucleated cells were found in the SFMC cultures after 21 days. These cells expressed the osteoclast genes calcitonin receptor, cathepsin K, and integrin β3, formed lacunae on dentin plates and secreted matrix metalloproteinase 9 (MMP9) and TRAP. Adding RANKL and M‐CSF potentiated this secretion. In conclusion, we show that SFMCs from inflamed peripheral joints can spontaneously develop into functionally active osteoclasts ex vivo. Our study provides a simple in vitro model for studying inflammatory osteoclastogenesis.  相似文献   
6.
Unilateral lesions of visual cortex have the secondary consequence of suppressing visual circuits in the midbrain superior colliculus (SC), collectively producing blindness in contralesional space (“hemianopia”). Recent studies have demonstrated that SC visual responses and contralesional vision can be reinstated by a non‐invasive multisensory training procedure in which spatiotemporally concordant visual‐auditory pairs are repeatedly presented within the blind hemifield. Despite this recovery of visual responsiveness, the loss of visual cortex was expected to result in permanent deficits in that hemifield, especially when visual events in both hemifields compete for attention and access to the brain's visuomotor circuitry. This was evaluated in the present study in a visual choice paradigm in which the two visual hemifields of recovered cats were simultaneously stimulated with equally valent visual targets. Surprisingly, the expected disparity was not found, and some animals even preferred stimuli presented in the previously blind hemifield. This preference persisted across multiple stimulus intensity levels and there was no indication that animals were less aware of cues in the previously blind hemifield than in its spared counterpart. Furthermore, when auditory cues were combined with visual cues, the enhanced performance they produced on a visual task was no greater in the normal than in the previously blind hemifield. These observations suggest that the multisensory rehabilitation paradigm revealed greater inherent visual information processing potential in the previously blind hemifield than was believed possible given the loss of visual cortex.  相似文献   
7.
8.
9.

Introduction The focus in clinical pharmacy practice is and has for the last 30–35 years been on changing the role of pharmacy staff into service orientation and patient counselling. One way of doing this is by involving staff in change process and as a researcher to take part in the change process by establishing partnerships with staff. On the background of the authors’ widespread action research (AR)-based experiences, recommendations and comments for how to conduct an AR-study is described, and one of their AR-based studies illustrate the methodology and the research methods used. Methodology AR is defined as an approach to research which is based on a problem-solving relationship between researchers and clients, which aims at both solving a problem and at collaboratively generating new knowledge. Research questions relevant in AR-studies are: what was the working process in this change oriented study? What learning and/or changes took place? What challenges/pitfalls had to be overcome? What were the influence/consequences for the involved parts? When to use If you want to implement new services and want to involve staff and others in the process, an AR methodology is very suitable. The basic advantages of doing AR-based studies are grounded in their participatory and democratic basis and their starting point in problems experienced in practice. Limitations Some of the limitations in AR-studies are that neither of the participants in a project steering group are the only ones to decide. Furthermore, the collective process makes the decision-making procedures relatively complex.

  相似文献   
10.
BackgroundChildren with adrenal suppression (AS), a potential side effect of glucocorticoids (GCs) may be asymptomatic, present with nonspecific signs and symptoms or with adrenal crisis. Asymptomatic AS (AAS) can only be diagnosed through screening. Identifying and treating asymptomatic patients before symptoms develop may reduce morbidity. Screening guidelines for AS are lacking. Consequently, screening practices are highly variable.ObjectiveTo assess (1) the screening practices for and recognition of paediatric AAS among clinicians in Canada and (2) the educational impact of a 2-year surveillance program of symptomatic AS cases.MethodsBefore and after a 2-year Canadian Paediatric Surveillance Program (CPSP) study of symptomatic AS, participants were surveyed through the CPSP. The prestudy survey was sent to 2,548 participants in March 2010 and the poststudy survey was sent to 2,465 participants in April 2013.ResultsResponse rates were 32% for the prestudy survey and 21% for the poststudy survey. Between the pre- and poststudy surveys, the percentage of physicians who reported routinely screening patients on GCs for AS increased from 10% to 21% and the percentage who reported having a screening policy in their office/centre increased from 6% to 11%. There was no significant change in the percentage of physicians who had diagnosed a child/youth with AAS in the preceding year.ConclusionFrequency of screening for AAS increased following the 2-year study but remains low. Development of a clinical practice guideline should increase both awareness of asymptomatic AS among Canadian paediatricians and the identification of AAS, before symptoms develop.  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