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   2243篇
  免费   133篇
  国内免费   49篇
耳鼻咽喉   28篇
儿科学   47篇
妇产科学   30篇
基础医学   319篇
口腔科学   101篇
临床医学   290篇
内科学   179篇
皮肤病学   4篇
神经病学   215篇
特种医学   164篇
外科学   529篇
综合类   201篇
预防医学   58篇
眼科学   51篇
药学   104篇
  6篇
中国医学   70篇
肿瘤学   29篇
  2024年   4篇
  2023年   41篇
  2022年   69篇
  2021年   114篇
  2020年   84篇
  2019年   84篇
  2018年   103篇
  2017年   69篇
  2016年   66篇
  2015年   63篇
  2014年   141篇
  2013年   144篇
  2012年   110篇
  2011年   128篇
  2010年   92篇
  2009年   127篇
  2008年   117篇
  2007年   102篇
  2006年   91篇
  2005年   71篇
  2004年   68篇
  2003年   50篇
  2002年   47篇
  2001年   52篇
  2000年   34篇
  1999年   36篇
  1998年   29篇
  1997年   29篇
  1996年   26篇
  1995年   23篇
  1994年   22篇
  1993年   23篇
  1992年   16篇
  1991年   11篇
  1990年   14篇
  1989年   4篇
  1988年   10篇
  1987年   13篇
  1986年   7篇
  1985年   8篇
  1984年   15篇
  1983年   11篇
  1982年   14篇
  1981年   12篇
  1980年   13篇
  1979年   7篇
  1977年   3篇
  1976年   2篇
  1974年   2篇
  1967年   2篇
排序方式: 共有2425条查询结果,搜索用时 15 毫秒
1.
2.
3.
目的对比动力髋螺钉(dynamic hip screw,DHS)治疗和股骨近端抗旋髓内钉(proximal femoral nail anti-rotation,PFNA)固定治疗老年股骨粗隆间骨折疗效。方法纳入本院收治的45例采用PFNA固定治疗的老年股骨粗隆间骨折患者作为研究组,研究时间为2017年11月-2018年11月;回顾性分析2016年11月-2017年11月在我院采用DHS治疗的45例老年股骨粗隆间骨折患者的临床资料,作为对照组。记录两组的相关手术指标,观察手术并发症情况。结果研究组的手术时间和骨折愈合时间均短于对照组,术中出血量明显少于对照组,术后疼痛VAS评分均明显低于对照组(P<0.05)。对照组的并发症发生率高于研究组(P<0.05)。结论PFNA固定治疗比DHS治疗老年股骨粗隆间骨折更加安全有效,值得临床借鉴和应用。  相似文献   
4.
This study evaluated the effect of new motions of the motor TriAuto ZX2 on the cyclic fatigue of endodontic instruments. Vortex Blue 35.06 instruments were divided into four groups (n = 10) and tested for fatigue in a curved artificial canal (90° and 2 mm radius) using the following motions: continuous rotation (CR), Optimum Torque Reverse (OTR) set at 180° and the Optimum Glide Path (OGP), which was tested at 90° and 240°. The time to fracture (TTF) and the lengths of the fractured fragments were recorded. The mean TTF was significantly different among the groups (anova , P < 0.05): OGP 90° (213.39 ± 27.45), OTR 180° (121.24 ± 17.03), OGP 240° (45.24 ± 5.61) and CR (8.43 ± 1.27). Weibull analysis confirmed the shortest life expectancy for CR and the longest survival for OGP at 90°. The resistance to fatigue was affected by motions and pre‐set angles. The proprietary movements that are currently available for endodontic instruments were classified according to their kinematics.  相似文献   
5.
熊焱昊  杜宁  陈伟珍 《中国骨伤》2006,19(4):207-210
目的:探讨椎动脉型颈椎病、交感型颈椎病、神经根型颈椎病之间颈椎旋转、半失稳的关系。方法:本组112例,其中椎动脉型38型、交感型36例、神经根型38例,应用图像存档和传输系统(picture archiving and communication systems,PACS)在X线正位片上测量患者每个颈椎椎体的旋转度和在侧位片上测量椎体半失稳的位移距离。结果:在C6旋转度上,椎动脉型颈椎病和交感型颈椎病均与神经根型颈椎病有统计学差异(P<0·01),椎动脉型颈椎病和交感型颈椎病间的C2旋转度有统计学差异(P<0·05),椎动脉型颈椎病和神经根型颈椎病间的C4旋转度有统计学差异(P<0·05)。在椎体半失稳的位移距离和椎体半失稳率上,椎动脉型颈椎病和交感型颈椎病均与神经根型颈椎病有统计学差异(P<0·01)。结论:在椎动脉型颈椎病和交感型颈椎病中椎体半失稳和颈椎旋转是它们发病的一个重要因素,而在神经根型颈椎病中不是发病的重要因素。  相似文献   
6.
Three-dimensional spinal curvature in idiopathic scoliosis   总被引:3,自引:0,他引:3  
Scoliosis is usually considered as a deformity of the spine in the frontal plane, without reference to curvatures in other planes. In this study, the three-dimensional shape of the spine of 104 patients with untreated idiopathic scoliosis (5-55 degrees Cobb) was studied by means of stereo radiographs to determine relationships between curvature of the spine in the frontal plane view, in the lateral view, and in the intermediate views. There was a weak but statistically significant correlation (r = 0.2) relating greater scoliosis with lesser kyphosis or greater lordosis. In the thoracic region, the sagittal plane spinal curvature was less than that measured in a population without scoliosis (mean difference, 7.72 +/- 9.9 degrees). Seventy-four of 76 scolioses in the upper region of the spine with lateral curvature greater than 5 degrees Cobb were kyphotic. Sixty-four of 84 curves greater than 5 degrees Cobb in the lower region were lordotic. Measuring curvatures in the plane of symmetry of the rotated apical vertebra altered these ratios to 69 of 76 kyphotic in the upper region and 68 of 84 lordotic in the lower region. The plane of maximum curvature of sections of the spine with scoliosis was not related to the plane of symmetry of the rotated apical vertebra, for in kyphotic regions of the spine the rotations of these two planes were in opposite directions. In all cases, the magnitudes of the rotations were quite different, i.e., by a factor of -0.22 for curves in thoracic region and by a factor of 0.24 for curves in the lumbar region. This implies that mechanical measures to correct this spinal deformity or to prevent progression should apply different rotations to the apex from those applied to the curve as a whole and, in opposite senses, in curves in kyphotic regions. There was no evidence of an abnormality of sagittal curvature of a magnitude to implicate it in the etiology or in the treatment.  相似文献   
7.
目的:观察整脊疗法对功能性消化不良患者血浆胃动素(MTL)和血清胃泌素(GAS)含量的影响,并探讨整脊疗法对该病的作用机制。方法:将功能性消化不良60例患者按随机分配原则分为两组,治疗组采用整脊疗法治疗,对照组口服贝络纳治疗,观察血浆胃动素、血清胃泌素含量的变化。结果:整脊疗法能提高MTL水平(P〈0.01),降低GAS(P〈0.05),其作用与贝络纳相仿。结论:通过对功能性消化不良患者血浆胃动素、血清胃泌紊含量变化的观察,整脊疗法可能通过调节脑一肠轴的脊柱前神经节影响胃肠神经系统改变胃肠黏膜分泌MTL和GAS的含量,改善胃肠功能。  相似文献   
8.
Mice ran in a circular runway. Some received milk at every third circuit in a designated direction, clockwise or counterclockwise, in daily 1000-s sessions. Under control conditions, about 10 times as many circuits were made in the reinforced direction as in the non-reinforced direction. Cocaine (10, 30, 100 µM/kg) had little effect on the total number of circuits, but progressively increased the number in the non-reinforced direction. Chlorpromazine (1, 3, 10, 30 µM/kg) caused a monotonic decrease in total number of circuits and in number in non-reinforced direction. At the highest doses the proportion in the non-reinforced direction was increased. Mice, untrained in the runway and with no reinforcement of circuits in either direction, made many fewer total circuits than when running was reinforced and about equal numbers were in clockwise and in counterclockwise directions. Cocaine greatly increased the total number of circuits. As in the subjects whose running was reinforced, cocaine led to a much higher tendency for mice to run in a single direction. The similarities between the tendency to run in one direction after cocaine and the rotational behavior of rodents seen after cocaine and amphetamine suggest a common mechanism.  相似文献   
9.
The purpose of this pilot study was to observe both relaxed and deep breathing patterns in a convenience sample to determine the incidence of normal versus faulty patterns of respiration. These observations were then combined with respondent answers to a survey on pain history to determine if there is any correlation between faulty breathing and musculo-skeletal pain patterns. If such a correlation can be made, then we propose that clinicians working with chronic pain patients may have improved outcomes if they address and correct faulty breathing patterns. Based on this study, it is suggested to include the evaluation and treatment of faulty respiration in the rehabilitation of chronic musculo-skeletal conditions, most notably cervical pain.  相似文献   
10.
寰枢关节旋转运动CT扫描的临床意义   总被引:4,自引:0,他引:4  
目的了解不同旋转状态下CT扫描寰枢关节的影像学变化,探讨CT对寰枢关节旋转固定的诊断价值。方法分别对正常组30例、寰枢关节旋转固定患者组16例、新鲜尸体标本组5例行头部功能位CT扫描,测量并比较各组的寰齿前间隙、寰齿侧间隙及寰枢椎相对旋转角的变化。结合标本解剖观察寰枢关节不同旋转状态在SSD法重建图像上的表现。结果不同旋转状态下CT扫描寰枢关节的影像表现变化较大。旋转前后正常组与寰枢关节旋转固定患者组相比:寰齿前间隙及寰枢关节相对旋转范围变化差异有显著性(P<0·01),寰齿侧间隙的变化差异无显著性(P>0·05),寰枢关节不同旋转状态下在SSD法重建图像上表现与标本解剖观察基本一致。结论静态CT扫描不能准确诊断Ⅰ型寰枢关节旋转固定,功能位CT扫描能够准确诊断寰枢关节旋转固定。  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