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   692篇
  免费   18篇
  国内免费   1篇
耳鼻咽喉   27篇
儿科学   103篇
妇产科学   20篇
基础医学   42篇
口腔科学   10篇
临床医学   52篇
内科学   135篇
皮肤病学   13篇
神经病学   51篇
特种医学   46篇
外科学   138篇
综合类   2篇
预防医学   10篇
眼科学   26篇
药学   18篇
肿瘤学   18篇
  2023年   1篇
  2022年   11篇
  2021年   9篇
  2020年   3篇
  2019年   9篇
  2018年   6篇
  2017年   7篇
  2016年   11篇
  2015年   21篇
  2014年   24篇
  2013年   38篇
  2012年   50篇
  2011年   35篇
  2010年   29篇
  2009年   22篇
  2008年   56篇
  2007年   53篇
  2006年   57篇
  2005年   77篇
  2004年   56篇
  2003年   44篇
  2002年   32篇
  2001年   12篇
  2000年   19篇
  1999年   5篇
  1998年   7篇
  1997年   1篇
  1996年   1篇
  1995年   2篇
  1994年   1篇
  1993年   2篇
  1987年   2篇
  1986年   1篇
  1984年   1篇
  1983年   1篇
  1981年   3篇
  1978年   1篇
  1967年   1篇
排序方式: 共有711条查询结果,搜索用时 15 毫秒
701.
702.
Background: Cardiovascular problems are a major cause of morbidity and mortality in patients with autosomal dominant polycystic kidney disease (ADPKD). Aim: The aim of this study was to investigate coronary flow velocity reserve (CFVR) as a marker of endothelial dysfunction, carotid intima media thickness (CIMT) as a marker of subclinical organ damage and insulin resistance (IR) as a cardiovascular risk factor in patients with ADPKD. Methods: Twenty‐two normotensive ADPKD patients with well‐preserved renal function and 19 healthy subjects were included in the study. Creatinine clearances were calculated by the Cockcroft–Gault formula. The homeostasis model of IR (HOMA‐IR) was used to measure IR. CIMT was measured by high‐resolution vascular ultrasound. CFVR was calculated as the ratio of hyperaemic to baseline diastolic peak velocities by echocardiography. Results: There was no significant difference between the two groups regarding age, gender, body mass index, systolic and diastolic blood pressures, cholesterol and triglyceride levels. However, CIMT and HOMA‐IR were significantly increased and CFVR was significantly decreased in patients with ADPKD compared with healthy subjects. Conclusions: The findings of decreased CFVR, increased CIMT and increased IR suggest that cardiovascular risk is elevated even in the early stages of ADPKD.  相似文献   
703.
704.
705.
Background: To evaluate retinal nerve fibre layer thickness and to compare results with visual evoked potentials and visual field in patients with multiple sclerosis. Design: A prospective, case‐control study, university hospital setting. Participants: Seventy‐three eyes of 37 multiple sclerosis patients and 74 eyes of 37 healthy subjects. Methods: All patients underwent a complete neurological and ophthalmological examination and peri‐papillary retinal nerve fibre layer thickness was evaluated using scanning laser polarimetry (GDx). Furthermore, visual evoked potential and visual field testing were performed. Main Outcome Measures: The χ2 test, Student's t‐test, Mann–Whitney U‐test and Pearson's correlation coefficient analysis of the GDx, visual evoked potential and visual field testing parameters. Results: GDx measurements showed significantly more retinal nerve fibre layer damage in the patients than in the control groups. Comparison of the GDx parameters between patients with optic neuritis and non‐optic neuritis demonstrated a statistically significant difference in symmetry (P = 0.046) and superior/nasal parameters (P = 0.009). A correlation was found between the number, superior and inferior ratio parameters, and P100 amplitude obtained with visual evoked potential in patients with non‐optic neuritis. Additionally, there was a correlation between the number, inferior ratio and superior/nasal parameters, and the mean deviation of visual field in the non‐optic neuritis group. Conclusions: For retinal nerve fibre layer thickness measurements in multiple sclerosis patients, the GDx, along with other techniques, such as visual evoked potential, can be used as a diagnostic and follow‐up criterion, particularly in patients without optic neuritis.  相似文献   
706.
707.
The Autocapture function controls and optimizes the amplitude of the pacing pulse and saves energy. The manufacturer recommends using a special low polarization, low threshold bipolar Pacesetter lead for the Autocapture function. The purpose of this study was to evaluate the compatibility of Autocapture with previously implanted pacing leads. The study included 15 patients (mean age 13.6 +/- 3.4 years) who needed pulse generator replacement and received the VVIR pacemaker Regency SR+ or the DDDR pacemakers Affinity DR or Integrity DR with the Autocapture function. The new pulse generators connected to previously implanted ventricular leads. At the time of implantation the pacing threshold was 1.0 +/- 0.35 V at 0.5 ms, the lead impedance was 580 +/- 80 omega, and the spontaneous R wave amplitude was 7.89 +/- 4.89 mV. The polarization signal (PS) was 3.8 +/- 3.04 mV, and evoked response (ER) was 8.15 +/- 4.57 mV at the predischarge testing. Follow-up telemetry was done at months 1, 3, 6, 12, and 18. The follow-up duration was 9.4 +/- 5 months (range 1-18 months). If the results of PS and ER measurements were acceptable for autocapture, it turned on at the 1-month visit. In six (40%) patients the results were found acceptable for autocapture function. Age, lead impedance, pacing threshold, intrinsic R wave measurement, lead age, fixation mechanism, and ER measurements were not statistically different in Autocapture suitable and not suitable groups. The main reason not to activate Autocapture had been increased PS. Any significant fluctuations were not observed in pacing threshold, lead impedance, ER, and PS during follow-up. In conclusion, previously implanted pacing leads may be compatible with the Autocapture function.  相似文献   
708.
Ventricular septal defects (VSD), which cause volume overload, may be closed by interventional method. The success depends on the precise anatomic definition of the defect and its relation to other cardiac structures. We report our first experiences of transcatheter closure of perimembranous and muscular VSD. Between May 2005 and September 2006, transcatheter closure of VSD was attempted in 38 patients. Implantation was successful in 37 patients. In one patient, the procedure failed because of the long sheath kinking. We observed important complications in three patients: severe tricuspid valve regurgitation, residual VSD and tricuspid valve regurgitation and right bundle branch block in the short-term follow-up. Transcatheter device closure with Amplatzer device seems to be effective and safe in the treatment of perimembranous and muscular VSDs. Tricuspid valve incompetence may cause problems. Long-term results are required to determine the efficacy and safety.  相似文献   
709.

Purpose  

Multi-detector Computed Tomography (MDCT) is an exquisite technique in demonstrating the cranial foramina. This study aimed to assess the anatomic variations and locations of mental foramina in living adult mandible by MDCT.  相似文献   
710.
INTRODUCTION: The aim of this study was to compare the measurements of vertebral artery (VA) systolic flow velocity and flow volume for diagnosis of vertebrobasilar insufficiency (VBI). MATERIAL AND METHODS: We examined 96 patients who were referred for evaluation of VBI. Net vertebral artery flow volume and mean systolic flow velocity were determined by using color duplex sonography. We had grouped the patients into three according to VA flow volume: group 1 was consisted of patients with severely damped VA flow volume (lower than 120 mL/min), group 2 was consisted of patients with moderately damped VA flow volume (120-200 mL/min), group 3 was consisted of patients with normal VA flow volume (>200 mL/min). The mean systolic flow velocities in each group were compared by one-way ANOVA. RESULTS: Mean VA systolic flow velocities of groups 1, 2 and 3 were 32 +/- 12, 42 +/- 10 and 46 +/- 8 cm/s, respectively. Mean VA systolic flow velocity in group 1 was significantly lower than that of group 2 (P = 0.001). However, there were no significant differences between VA systolic flow velocities in groups 2 and 3 (P = 0.2). CONCLUSIONS: According to our findings, measurement of volume in addition to velocity is more valuable in detection of moderately damped VA flow volumes in diagnosis of VBI.  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