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   636篇
  免费   42篇
  国内免费   29篇
耳鼻咽喉   2篇
儿科学   17篇
妇产科学   1篇
基础医学   50篇
口腔科学   37篇
临床医学   76篇
内科学   122篇
皮肤病学   63篇
神经病学   48篇
特种医学   112篇
外科学   62篇
综合类   22篇
预防医学   38篇
眼科学   5篇
药学   33篇
肿瘤学   19篇
  2023年   1篇
  2022年   1篇
  2021年   2篇
  2020年   3篇
  2019年   9篇
  2018年   8篇
  2017年   4篇
  2016年   5篇
  2015年   9篇
  2014年   12篇
  2013年   25篇
  2012年   23篇
  2011年   27篇
  2010年   24篇
  2009年   22篇
  2008年   24篇
  2007年   39篇
  2006年   21篇
  2005年   24篇
  2004年   16篇
  2003年   19篇
  2002年   23篇
  2001年   26篇
  2000年   13篇
  1999年   22篇
  1998年   23篇
  1997年   29篇
  1996年   27篇
  1995年   9篇
  1994年   29篇
  1993年   25篇
  1992年   8篇
  1991年   6篇
  1990年   9篇
  1989年   22篇
  1988年   18篇
  1987年   14篇
  1986年   7篇
  1985年   14篇
  1984年   6篇
  1983年   6篇
  1982年   7篇
  1981年   12篇
  1980年   5篇
  1979年   6篇
  1978年   5篇
  1977年   6篇
  1976年   5篇
  1975年   5篇
  1869年   1篇
排序方式: 共有707条查询结果,搜索用时 0 毫秒
71.
72.
73.

Purpose  

Multiple studies indicate that T-cells play a major role in the pathogenesis of experimental autoimmune encephalomyelitis (EAE), the animal model of multiple sclerosis, but recently an involvement of antibodies has also been discussed. The aim of our study was to examine the effects of myelin basic protein (MBP) immunization on survival of neurons, alteration of antibody reactivity, and microglia in the retinal ganglion cell layer.  相似文献   
74.
BACKGROUND: Chronic intrathecal delivery of baclofen has been introduced for treatment of severe spinal spasticity. Very little is known about this treatment in hereditary spastic paraparesis. Here we review the benefits and limitations of pump implantation for baclofen delivery in this population. METHODS: Consecutive patients presenting with hereditary spastic paraparesis were assessed for spasticity (Ashworth and Penn scores), muscular strength and walking (speed, comfort and perimeter length). The effect of intrathecal delivery of baclofen was judged after progressive bolus injections or chronic administration by electrical syringe. The pump implantation was proposed when spasticity scores decreased by 2 or more points, with muscular strength preserved and walking area increased. RESULTS: We investigated 6 patients (3 males; mean age 48 years) with hereditary spastic paraparesis. The mean follow-up was 19 years; for 4 patients who received pump implantation, the mean follow-up was 6.2 years. The mean baclofen daily dose was 75 mug. Satisfaction was high for patients who received implantation early instead of waiting for the natural course of the disease. DISCUSSION: Some patients with hereditary spastic paraparesis have good functional improvement with chronic intrathecal delivery of baclofen if walking is still possible. Despite the natural history of the disease, functional results are stable during the first 5 years of treatment. The data indicate a possible compromise between decreased spasticity and muscular strengthening with the treatment.  相似文献   
75.
Proximal humeral fractures in 67 patients older than 50 years treated with the Telegraph nail (FH Orthopedics, Heimsbrunn, France) were monitored for 4 years to assess the fracture pattern (weighted Constant score), ranges of motion, and patient satisfaction. The outcome was best in patients with extraarticular surgical neck fractures (mean weighted Constant score, 93.5%); scores were 85% and 77.5%, respectively, for valgus impacted fractures and intraarticular displaced or dislocated fractures. Some or all of the hardware was removed in 21 patients (31%). Two required implant removed for mechanical problems related to screw positioning or migration; 8 were revised because proximal migration of the implant resulted in subacromial impingement. Avascular necrosis occurred in 18% of valgus impacted fractures and in 37.5% of displaced articular or dislocated fractures. Secondary migration of the tuberosities occurred in 6 (all 4-part fractures). The Telegraph nail provides a reproducible and satisfactory outcome for surgical neck and valgus impacted fractures in older patients. The outcome was less satisfactory for unstable articular or dislocated fractures.  相似文献   
76.
77.
评价无支架异种生物瓣膜主动脉瓣替换术后2年左室功能的变化。将80例同期施行主动脉瓣替换病人分为2组,50例(年龄69.3±9.3岁)应用TorontoSPVTM瓣;30例(年龄71.6±7.7岁)作为对照组接受支架人工瓣膜替换。术前、术后1、6、12及24个月间记录M型及Doppler超声心动图,采用计算机图像数字分析,定量测定左室功能的变化。随访期间,Toronto组主动脉瓣跨瓣压差为0.8±0.6kPa(6.0±4.5mmHg),明显低于对照组2.3±0.9kPa(17.3±6.8mmHg);术后1个月,左室心肌质量下降25%,左室+Vcf及-Vcf明显增加(2.0±0.8/1.4±0.3s-1,P<0.01;2.8±1.2/1.8±0.7s-1,P<0.01)。术后6个月,左室功能进一步改善,心室肥厚的消退更趋完全,该变化在其后的随访期间保持稳定。结论:与支架瓣膜相比,无支架异种生物瓣膜具有较大瓣口开放面积及低跨瓣压差,这促进了术后左室功能的恢复及病理性肥厚的逆转  相似文献   
78.
The progressive development of deficits in executive functions, including action planning, is a well‐known complication of Parkinson's disease. A dysfunction of the prefrontal lobe, which is known to be involved in the control of inhibitory processes, could explain the difficulties in initiating behavior or inhibiting ongoing actions in patients with PD. The strong dopaminergic innervation of the prefrontal cortex raises questions about the putative effects of dopa therapy on this cognitive impairment. In the present study, we used fMRI to examine the functional influence of dopa therapy on neural activity during a go/no‐go task in nine patients with and without levodopa treatment and in matched controls. Whereas the patient and control subjects exhibited the same performance during the go/no‐go task, different patterns of brain activation were observed depending on the dopaminergic status. The drug‐off state was characterized by more widely distributed brain activity, mainly in the bilateral caudate. Levodopa did not fully restore normal brain activation and induced changes in the pattern of cingulate cortex activity, which was more pronounced in the rostral part in the drug‐off state and in the caudal part after levodopa intake. These results support the idea of a critical role for dopamine in the control of executive functions in patients with PD. © 2009 Movement Disorder Society  相似文献   
79.
80.
Thoracic spiral CT: influence of subsecond gantry rotation on image quality   总被引:3,自引:0,他引:3  
  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