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   763篇
  免费   63篇
  国内免费   5篇
耳鼻咽喉   9篇
儿科学   59篇
妇产科学   6篇
基础医学   75篇
口腔科学   27篇
临床医学   69篇
内科学   103篇
皮肤病学   19篇
神经病学   108篇
特种医学   82篇
外科学   188篇
综合类   18篇
预防医学   12篇
药学   31篇
肿瘤学   25篇
  2023年   2篇
  2022年   4篇
  2021年   10篇
  2020年   5篇
  2019年   14篇
  2018年   17篇
  2017年   19篇
  2016年   13篇
  2015年   19篇
  2014年   27篇
  2013年   31篇
  2012年   42篇
  2011年   47篇
  2010年   56篇
  2009年   30篇
  2008年   24篇
  2007年   40篇
  2006年   33篇
  2005年   31篇
  2004年   17篇
  2003年   21篇
  2002年   15篇
  2001年   10篇
  2000年   9篇
  1999年   14篇
  1998年   29篇
  1997年   36篇
  1996年   34篇
  1995年   29篇
  1994年   18篇
  1993年   17篇
  1992年   5篇
  1991年   3篇
  1990年   1篇
  1989年   16篇
  1988年   16篇
  1987年   18篇
  1986年   10篇
  1985年   8篇
  1984年   4篇
  1983年   3篇
  1982年   6篇
  1981年   10篇
  1980年   4篇
  1979年   2篇
  1978年   1篇
  1977年   5篇
  1976年   5篇
  1954年   1篇
排序方式: 共有831条查询结果,搜索用时 484 毫秒
31.
Casha S  Yu WR  Fehlings MG 《Neuroscience》2001,103(1):203-218
Apoptosis or programmed cell death has been reported after CNS trauma. However, the significance of this mechanism in the pathophysiology of spinal cord injury, in particular at the cervical level, requires further investigation. In the present study, we used the extradural clip compression model in the rat to examine the cellular distribution of apoptosis following cervical spinal cord injury, the relationship between glial apoptosis and post-traumatic axonal degeneration and the possible role of apo[apoptosis]-1, CD95 (FAS) and p75 in initiating post-traumatic glial apoptosis. In situ terminal-deoxy-transferase mediated dUTP nick end labeling revealed apoptotic cells, largely oligodendrocytes as identified by cell specific markers, in grey and white matter following spinal cord injury. Apoptotic cell death was confirmed using electron microscopy and by the demonstration of DNA laddering on agarose gel electrophoresis. Beta-amyloid precursor protein was used as a molecular marker of axonal degeneration on western blots and immunohistochemistry. Degeneration of axons was temporally and spatially co-localized with glial apoptosis. FAS and p75 protein expression was seen in astrocytes, oligodendrocytes and microglia, and was also seen in some apoptotic glia after cord injury. Both FAS and p75 increased in expression in a temporal course, which mirrored the development of cellular apoptosis. The downstream caspases 3 and 8, which are linked to FAS and p75, demonstrated activation at times of maximal apoptosis, while FLIP-L an inhibitor of caspase 8, decreased at times of maximal apoptosis. We conclude that axonal degeneration after traumatic spinal cord injury is associated with glial, in particular oligodendroglial, apoptosis. Activation of the FAS and p75 death receptor pathways may be involved in initiating this process.  相似文献   
32.
33.
An international panel reviewed the methodology for clinical trials of spinal cord injury (SCI), and provided recommendations for the valid conduct of future trials. This is the second of four papers. It examines clinical trial end points that have been used previously, reviews alternative outcome tools and identifies unmet needs for demonstrating the efficacy of an experimental intervention after SCI. The panel focused on outcome measures that are relevant to clinical trials of experimental cell-based and pharmaceutical drug treatments. Outcome measures are of three main classes: (1) those that provide an anatomical or neurological assessment for the connectivity of the spinal cord, (2) those that categorize a subject's functional ability to engage in activities of daily living, and (3) those that measure an individual's quality of life (QoL). The American Spinal Injury Association impairment scale forms the standard basis for measuring neurologic outcomes. Various electrophysiological measures and imaging tools are in development, which may provide more precise information on functional changes following treatment and/or the therapeutic action of experimental agents. When compared to appropriate controls, an improved functional outcome, in response to an experimental treatment, is the necessary goal of a clinical trial program. Several new functional outcome tools are being developed for measuring an individual's ability to engage in activities of daily living. Such clinical end points will need to be incorporated into Phase 2 and Phase 3 trials. QoL measures often do not correlate tightly with the above outcome tools, but may need to form part of Phase 3 trial measures.  相似文献   
34.
PURPOSE OF REVIEW: This review discusses some of the recent advances and current controversies in the acute clinical management of traumatic brain injury (TBI) and spinal cord injury (SCI). RECENT FINDINGS: Several key risk factors for adverse prognosis in TBI have been identified, including female sex. In the management of intracranial hypertension antibiotic impregnated intraventricular catheters have been found to reduce the risk for infection, and new studies have examined the roles of mannitol, hyperventilation, and hypothermia. Moderate hypothermia has also been found to improve outcome. Hyperoxia is now being explored as a treatment option for improving brain metabolism in TBI. That acute SCI continues to be a challenging diagnosis is supported by a recent study that showed that 9.1% of SCIs are missed initially. The diagnosis and management of spinal instability has been studied in different patient groups. In SCI without radiographic abnormality, the presence of normal magnetic resonance imaging findings was associated with a good prognosis. New studies in the field of early decompression and the prevention of thromboembolism in SCI have also been published. Guidelines for the management of acute SCI recommend methylprednisolone and GM-1 ganglioside only as options. SUMMARY: In neurotrauma some established treatments have been re-examined and their efficacy proven, whereas others that were once considered the standard of care in SCI, such as methylprednisolone, have been questioned. Large multicenter trials are needed to assess treatments such as early decompression in SCI and decompressive craniectomy in TBI. A truly effective neuroprotective therapy in neurotrauma remains elusive.  相似文献   
35.
36.
37.
Background The repair of an alar nasal defect is a frequent challenge for dermatologic surgeons for reasons of the high rate of non‐melanoma cancers in the area. Objective Our aim was to describe the use of an east–west cheek‐based flap (horizontal advancement flap) to repair a surgical defect on the nose ala. Methods Benefits and limits of this surgical procedure are evaluated. Result The resulting S‐shaped scar was well‐camouflaged among the natural skin lines (melolabial fold and melonasal junction). No architectural distortion of the nose resulted from the procedure. Conclusion In selected patients with small‐to‐medium‐size defects of the nasal ala, the horizontal advancement flap is a simple, reliable and aesthetic reconstruction option.  相似文献   
38.
39.
Knotting of intravascular catheters is an uncommon but a well‐recognized occurrence. The Swan–Ganz catheter (SGC) is the one that knots most commonly. A case of a knotted SGC is described in a patient with a persistent left‐sided superior vena cava, and we propose that the presence of a left‐sided superior vena cava is a risk factor for knot formation not previously reported. We review the published work on the risk factors for knot formation and on the techniques used to remove knotted SGC. We describe a technique using a gooseneck snare and Omni Flush catheter (Angiodynamics, Queensbury, NY, USA) to loosen and untie a knotted SGC.  相似文献   
40.
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