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   1494篇
  免费   80篇
  国内免费   57篇
耳鼻咽喉   3篇
儿科学   90篇
妇产科学   12篇
基础医学   198篇
口腔科学   24篇
临床医学   190篇
内科学   344篇
皮肤病学   56篇
神经病学   47篇
特种医学   353篇
外科学   79篇
综合类   27篇
预防医学   66篇
眼科学   5篇
药学   68篇
中国医学   2篇
肿瘤学   67篇
  2023年   7篇
  2022年   5篇
  2021年   11篇
  2020年   10篇
  2019年   13篇
  2018年   28篇
  2017年   24篇
  2016年   9篇
  2015年   23篇
  2014年   22篇
  2013年   51篇
  2012年   45篇
  2011年   39篇
  2010年   46篇
  2009年   67篇
  2008年   42篇
  2007年   76篇
  2006年   40篇
  2005年   36篇
  2004年   25篇
  2003年   23篇
  2002年   31篇
  2001年   37篇
  2000年   28篇
  1999年   37篇
  1998年   74篇
  1997年   82篇
  1996年   104篇
  1995年   61篇
  1994年   59篇
  1993年   54篇
  1992年   24篇
  1991年   23篇
  1990年   23篇
  1989年   41篇
  1988年   39篇
  1987年   36篇
  1986年   54篇
  1985年   45篇
  1984年   12篇
  1983年   14篇
  1982年   18篇
  1981年   9篇
  1980年   11篇
  1979年   9篇
  1978年   12篇
  1977年   9篇
  1976年   13篇
  1975年   13篇
  1972年   4篇
排序方式: 共有1631条查询结果,搜索用时 15 毫秒
991.
BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) has become an increasingly important pathogen responsible for hospital-acquired infections. Our study was to evaluate the efficiency of our selective screening program for methicillin-resistant Staphylococcus aureus (MRSA) carriers at admission to nonintensive care units. METHODS: During 6 months, all patients were screened at admission to an internal medicine ward, at which time they were classified as patients at risk of carriage (PRC) and those with no known risk factor. The amplitude of cross transmission was estimated using various indicators during this universal screening period and during the same calendar period of the preceding year (selective screening). RESULTS: The prevalence of MRSA carriage at admission was 5.5%. Among the 22 carriers identified, only 10 were PRC. Age >80 years was significantly associated with MRSA carriage upon admission (OR, 3.5; P < .01). All estimation indicators of MRSA dissemination amplitude were significantly lower during universal screening (relative risks varied from 2.79 to 26.4 according to indicators), demonstrating the need to broaden our criteria defining PRC. CONCLUSION: Adding patients >80 years of age to our PRC definition would increase screening sensitivity (15 carriers identified for 128 patients sampled) and would enable early implementation of barrier precautions for the additional carriers identified.  相似文献   
992.
INTRODUCTION: Streptococcus pneumoniae primary peritonitis is rare. The diagnosis is uneasy and the treatment is not standardised. CASE REPORT: We report a single case of S. pneumoniae primary peritonitis needing surgical treatment. DISCUSSION: S. pneumoniae primary peritonitis can be medically treated. Surgery is needed in case of sepsis, associated digestive injuries or failure of medical treatment.  相似文献   
993.
目前,尚不明确预防原因不明、合并卯圆孔未闭(patent foramen ovale,PFO)患者的卒中或短暂性脑缺血再次发作的最佳措施。众多观察性研究发现,PFO与原因不明的卒中虽密切相关,但在大多数发病的患者中,两者间并未明确因果关系。治疗措施包括:抗血小板聚集或维生素K拮抗剂的药物治疗、经皮封堵术及外科手术修补。  相似文献   
994.
本文系统地介绍了美国糖尿病协会关于糖尿病神经病变的诊断和治疗指南,包括糖尿病周围神经病变的定义和分类、诊断标准和临床表现、流行病学,如何早期筛查、预防及治疗原则.  相似文献   
995.
996.
Evidence from animal and human models has demonstrated the importance of hip proprioceptors and vestibular inputs in modulating lower-extremity muscle activity through reflex pathways. Comprehension of the role of these sensory inputs following stroke may be important in understanding pathological muscle activity during functional activities. We therefore examined the influence of both hip and head/trunk position on volitional quadriceps activity in chronic stroke and control subjects. With the knee held at 60 degrees, maximal voluntary isometric quadriceps contractions were elicited with trunk orientation (head position) and hip angle systematically positioned at 0 degrees, 45 degrees, and 90 degrees. Integrated electromyographic activity from the quadriceps was compared between groups and conditions. Vasti activity in the stroke group was greater in a seated upright posture (hip flexed) than supine (hip neutral). Controlling for vestibular input, the stroke group demonstrated greater quadriceps activity (VL and RF) with a neutral hip compared to flexion. Such findings may have implications for understanding inappropriate muscle activity during walking after stroke, as hip extension occurs immediately prior to toe off, when inappropriate quadriceps activity is commonly observed.  相似文献   
997.
BACKGROUND AND PURPOSE: Preoperative localization of the artery of Adamkiewicz (AKA) may be useful in selected children in prevention of ischemic spinal complications of spinal or thoracoabdominal aortic surgery. The aim of our study was to investigate the ability of 64-section CT for assessing the AKA in children. MATERIALS AND METHODS: Forty children (mean age, 7.5 +/- 5 years) underwent thoracic imaging with a 64-section CT scanner after intravenous injection of 1.5 mL/kg of contrast agent. Volumetric reconstructions were obtained for every patient. Identification of the AKA was performed on the basis of continuity from the aorta to the anterior spinal artery with a characteristic hairpin turn. Identification of the AKA and determination of its origin and course were analyzed by 2 independent radiologists. RESULTS: The AKA was successfully visualized in 38 patients (95%). Twenty-seven (71.1%) AKAs originated on the left side, whereas 11 (28.9%) originated on the right side. It was seen to originate at the level of the left 5th intercostal artery in 1 patient, the left 8th in 4, the left 9th in 15, the left 10th in 5, the left 11th in 2, the right 8th in 2, the right 9th in 6, the right 10th in 2, and the right 12th in 1. CONCLUSION: Sixty-four-section CT angiography depicted the AKA in a very high percentage (95%) of children. The results of this study suggest that 64-section CT angiography is a viable noninvasive technique that could be an alternate to selective angiography for delineating the AKA.  相似文献   
998.
The reflex torque responses of the elbow and shoulder to constant velocity angular extensions of the full comfortable range of the spastic elbow were measured in 16 people with unilateral stroke and 6 neurologically intact controls in order to identify the interjoint reflex coupling that occurs after stroke. The resulting responses showed a substantial reflex torque at the elbow and shoulder in subjects with stroke, with 12 of the 16 subjects producing adduction of the shoulder in response to passive extension of the elbow. The presence of simultaneous shoulder flexion torque with elbow flexion torque and with an identical waveform indicated an active role of biarticular elbow/shoulder flexors, such as the biceps. As the biceps muscle produces a shoulder abduction moment, shoulder adduction produced during elbow extension was thought to be associated with neural rather than biomechanical coupling. These results suggest that spasticity in people with stroke is more complex than its traditional perception as a hyperexcitable stretch reflex, and includes potent heteronymous reflex pathways. The reflex coupling observed between the shoulder and elbow should be considered in the diagnosis and clinical management of spasticity. The potential impact of this reflex on the coordination of volitional arm movements will be examined in future studies.  相似文献   
999.
1000.
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