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   501篇
  免费   25篇
耳鼻咽喉   7篇
儿科学   44篇
妇产科学   2篇
基础医学   36篇
口腔科学   6篇
临床医学   35篇
内科学   127篇
皮肤病学   19篇
神经病学   42篇
特种医学   1篇
外科学   75篇
综合类   5篇
预防医学   12篇
眼科学   9篇
药学   58篇
中国医学   3篇
肿瘤学   45篇
  2021年   6篇
  2017年   3篇
  2016年   10篇
  2015年   12篇
  2014年   6篇
  2013年   10篇
  2012年   8篇
  2011年   3篇
  2010年   16篇
  2009年   12篇
  2008年   2篇
  2007年   9篇
  2006年   24篇
  2005年   8篇
  2004年   10篇
  2003年   12篇
  2002年   13篇
  2001年   4篇
  2000年   3篇
  1999年   8篇
  1998年   28篇
  1997年   35篇
  1996年   19篇
  1995年   31篇
  1994年   14篇
  1993年   12篇
  1992年   10篇
  1991年   10篇
  1990年   7篇
  1989年   4篇
  1988年   8篇
  1987年   9篇
  1986年   9篇
  1985年   8篇
  1984年   5篇
  1983年   4篇
  1982年   4篇
  1981年   5篇
  1980年   5篇
  1979年   2篇
  1978年   2篇
  1977年   5篇
  1975年   2篇
  1964年   3篇
  1959年   6篇
  1958年   16篇
  1957年   21篇
  1956年   12篇
  1955年   21篇
  1954年   23篇
排序方式: 共有526条查询结果,搜索用时 8 毫秒
521.
Role of Vagal Control in Vasovagal Syncope   总被引:4,自引:0,他引:4  
SUZUKI, M., et al .: Role of Vagal Control in Vasovagal Syncope. The vasovagal reaction is thought to be caused by sympathetic withdrawal and vagal augmentation. While measurements of muscle sympathetic nerve activity support sympathetic withdrawal in tilt induced syncope, the results of previous attempts to quantify vagal control using spectral analyses of heart rate variability (HRV) remain controversial. The sampling period used in the HRV studies is related to the discordant results. In the present study, HRV was computed every second using wavelet transformation to clarify the role of vagal control in tilt induced syncope during the 80-degree head-up tilt test (positive: 10 patients with vasovagal syncope; negative: 10 patients with vasovagal syncope, and 10 control subjects). Autonomic modulations were assessed using the absolute power of the low frequency (LF) (0.04–0.15 Hz) and high frequency (HF) (0.15–2.00 Hz) oscillatory components of R-R variability. Although the LF did not change during the tilt procedure, a decrease in the systolic arterial pressure (SAP) and increases in the R-R interval and HF were observed for the last 30 seconds before the tilt induced syncope in the tilt-positive group. Analyzing the hemodynamic measurements and spectral indices for the last 5 minutes preceding the tilt induced syncope, the study found that the SAP, R-R interval, and HF changed simultaneously during the 30-second period immediately before the tilt induced syncope. Further, the HF was positively correlated with the R-R interval and negatively correlated with the SAP. In conclusion, continuous spectral analysis of the R-R interval demonstrated increased vagal influence on the heart in tilt induced syncope. (PACE 2003; 26[Pt. I]:571–578)  相似文献   
522.
目的比较探讨中日两国痴呆老人患病类型及精神行为症状(BPSD)发生率的差异。方法以辽宁省沈阳市苏家屯地区3432例65岁以上老年人为调查对象进行痴呆的流行病学调查,并与在日本新渴县丝鱼川地区调查结果比较。结果(1)调查地区痴呆的患病率为8.13%,低于日方调查结果10.6%。其中阿尔茨海默病(AD)占23.9%(日本为57.1%),血管性痴呆(VD)为56.6%(日本为22.6%)。(2)痴呆患者的精神行为症状(BPSD)的发生率两国之间无明显性差异,但不安症状、忧郁、烦躁、依赖等情感方面的变化以及大小便失禁症状方面,中方的发生率明显高于日方。结论老年痴呆已经成为当今中国的一个重大社会问题,中日两国痴呆患者患病类型及BPSD发生率出现差异的原因与两国之间的医疗保障制度以及生活水平不同相关。  相似文献   
523.
Although microvascular decompression (MVD) is a reliable treatment for hemifacial spasm (HFS), postoperative delayed relief of persistent HFS is one of the main issues. In patients with hemifacial spasm, stimulation of a branch of the affected facial nerve elicits an abnormal response in the muscles innervated by another branch. Several specific types of waves were found in the abnormal muscle response (AMR). This study aimed to confirm the relationship between the initial morphology of the AMR wave and delayed relief of persistent HFS after MVD. We retrospectively analyzed and compared the data from 47 of 155 consecutive patients who underwent MVD for HFS at our hospital between January 2015 and March 2020. Based on the pattern of the initial AMR morphology on orbicularis oculi and mentalis muscle stimulation, patients were divided into two groups, namely, the monophasic and polyphasic groups. The results of MVD surgery for HFS were evaluated 1 week, 1 month, and 1 year postoperatively, by evaluating whether or not the symptoms of HFS persisted at the time of each follow-up. There were significantly higher rates of persistent postoperative HFS in patients with the polyphasic type of initial AMR at 1 week and 1 month after the surgery (p < 0.05, respectively), as assessed using Yates chi-squared test and Fisher''s exact test. A significant correlation was observed between delayed relief after MVD and polyphasic morphology of the AMR in electromyographic analysis in patients with hemifacial spasm.  相似文献   
524.
Middle meningeal artery embolization (MMAE) for chronic subdural hematoma (CSDH) is a novel, minimally invasive treatment. The indications and treatment practices for MMAE are variable and remain controversial. This study aimed to evaluate a strategy involving sequential MMAE after burr hole surgery for treating recurrent CSDH. We performed a retrospective analysis of data from consecutive patients who had undergone MMAE using liquid embolic agents within approximately 2 weeks after burr hole surgery for recurrent CSDH from September 2020 to March 2022. We analyzed patient characteristics, procedural details, CSDH recurrence after MMAE, surgical rescue, and complications. Six of the nine patients who underwent MMAE for CSDH recurrence were male, and the median age was 85 (range, 70-94) years. Five of the nine patients were being administered antithrombotic agents. The median duration between the burr hole surgery and MMAE procedure was 10 (range, 3-25) days. Anterior and posterior convexity branches were targeted for embolization using low-concentration N-butyl cyanoacrylate (NBCA), and the abnormal vascular networks with a cotton wool appearance disappeared after embolization in all cases. The NBCA distribution was observed by high-resolution computed tomography during the procedure; in three of nine cases, the NBCA penetrated not only the MMA but also the inner membrane. No recurrence, surgical rescue, or complications were observed in any patient during the median follow-up period of 3 months. As a minimally invasive treatment for recurrent CSDH, sequential MMAE after burr hole surgery may be a safe and effective option for preventing recurrence.  相似文献   
525.
526.
Dabigatran and warfarin are oral anticoagulant drugs widely used for the prevention of stroke in patients with atrial fibrillation. The objective of this study was to evaluate the interaction between aging and dabigatran- and warfarin-induced gastrointestinal (GI) and nervous system hemorrhage using data available in the FDA Adverse Event Reporting System (FAERS) database.We analyzed reports of hemorrhagic events in the GI and nervous system recorded in the FAERS database between 2004 and 2014 using an adjusted reporting odds ratio (ROR).We demonstrated that dabigatran-associated GI hemorrhage was significantly increased in patients over the age of 80 years. The RORs of dabigatran increased with increasing age, although aging had little effect on warfarin-associated GI hemorrhage. The ROR for anticoagulant-associated nervous system hemorrhage was not significantly affected by aging, as compared to GI hemorrhage.Our results indicate that the excretion of dabigatran may be affected by aging, as compared to warfarin, likely due to renal function decline. Our results emphasize the need for physicians to closely monitor GI bleeding in aging patients, because it is closely related to renal function deterioration.  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