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   4583篇
  免费   114篇
  国内免费   42篇
耳鼻咽喉   154篇
儿科学   25篇
妇产科学   12篇
基础医学   970篇
口腔科学   154篇
临床医学   274篇
内科学   150篇
皮肤病学   7篇
神经病学   999篇
特种医学   203篇
外科学   983篇
综合类   352篇
预防医学   61篇
眼科学   82篇
药学   189篇
  1篇
中国医学   44篇
肿瘤学   79篇
  2023年   92篇
  2022年   145篇
  2021年   195篇
  2020年   124篇
  2019年   128篇
  2018年   124篇
  2017年   112篇
  2016年   116篇
  2015年   103篇
  2014年   202篇
  2013年   195篇
  2012年   192篇
  2011年   198篇
  2010年   170篇
  2009年   166篇
  2008年   172篇
  2007年   156篇
  2006年   158篇
  2005年   123篇
  2004年   115篇
  2003年   95篇
  2002年   75篇
  2001年   64篇
  2000年   74篇
  1999年   77篇
  1998年   70篇
  1997年   58篇
  1996年   64篇
  1995年   61篇
  1994年   46篇
  1993年   57篇
  1992年   47篇
  1991年   54篇
  1990年   66篇
  1989年   53篇
  1988年   65篇
  1987年   72篇
  1986年   60篇
  1985年   94篇
  1984年   77篇
  1983年   38篇
  1982年   52篇
  1981年   42篇
  1980年   48篇
  1979年   41篇
  1978年   32篇
  1977年   36篇
  1976年   25篇
  1975年   23篇
  1973年   29篇
排序方式: 共有4739条查询结果,搜索用时 0 毫秒
1.
ObjectiveTo determine if individuals with chronic ankle instability (CAI) demonstrate altered landing kinematics, muscle activity, and impaired dynamic postural stability during a unilateral jump-landing task.Methods21 studies were included from PubMed, MEDLINE, Embase and CINAHL searched on September 26, 2021. Mean differences in joint angles and muscle activity between CAI and controls were analysed as continuous variables and pooled using a random-effects model to obtain standardised mean differences and 95% confidence intervals. Dynamic postural stability measured using time to stabilisation (TTS) was assessed qualitatively.ResultsWe found greater plantarflexion (pooled SMD = 0.33, 95%CI [0.02,0.65]), reduced knee flexion (pooled SMD = −0.67, 95%CI [−0.97, −0.37]), and reduced hip flexion (pooled SMD = −0.52, 95%CI [−0.96, −0.07]) in CAI after landing. Regarding muscle activity, we observed reduced peroneus longus muscle activation (pooled SMD = −0.77, 95% CI [−1.17, −0.36]) in CAI prior to landing.ConclusionOur study provides preliminary evidence of altered landing kinematics in the sagittal plane and reduced peroneus muscle activity in CAI during a dynamic jump-landing task. These results may have clinical implications in the development of more effective and targeted rehabilitation programmes for patients with CAI.  相似文献   
2.
3.
Over the past 20 years there has been a growing interest in the neural underpinnings of cost/benefit decision-making. Recent studies with animal models have made considerable advances in our understanding of how different prefrontal, striatal, limbic and monoaminergic circuits interact to promote efficient risk/reward decision-making, and how dysfunction in these circuits underlies aberrant decision-making observed in numerous psychiatric disorders. This review will highlight recent findings from studies exploring these questions using a variety of behavioral assays, as well as molecular, pharmacological, neurophysiological, and translational approaches. We begin with a discussion of how neural systems related to decision subcomponents may interact to generate more complex decisions involving risk and uncertainty. This is followed by an overview of interactions between prefrontal-amygdala-dopamine and habenular circuits in regulating choice between certain and uncertain rewards and how different modes of dopamine transmission may contribute to these processes. These data will be compared with results from other studies investigating the contribution of some of these systems to guiding decision-making related to rewards vs. punishment. Lastly, we provide a brief summary of impairments in risk-related decision-making associated with psychiatric disorders, highlighting recent translational studies in laboratory animals.  相似文献   
4.
IntroductionCentral venous catheter applications and complications are closely related to the tip position. Previous studies have reported some rare cases of catheter misplacement. Here, we report a case of misplacement of a peripherally inserted central catheter into the lateral thoracic vein.Case reportA 56-year-old cancer patient underwent placement of a peripherally inserted central catheter through the left basilic vein under ultrasound-guided puncture. The catheterisation procedure was uneventful, so the catheter was believed to be in the superior vena cava. However, the post-anterior chest X-ray image revealed that after the catheter advanced towards the axilla, it turned downwards and outwards in the direction of the left lateral thoracic region, with the projection of the catheter tip giving the appearance of termination in the subcutaneous tissue of the lateral thoracic wall on the two-dimensional image. The catheter was then repositioned in the distal superior vena cava.DiscussionPeripherally inserted central catheters can be potentially misplaced into the lateral thoracic vein because these catheters can pass through the orifice of the lateral thoracic vein which flows into the axillary vein. Some pathological cases and clinical conditions can cause dilatation of the lateral thoracic vein, which increases the probability of catheter misplacement. Three principles were proposed to avoid this rare complication: a comprehensive review of the patients’ medical history, real-time image-guided catheterisation and routine radiographic identification of the tip position.  相似文献   
5.
Bone stock preservation is crucial when performing total hip replacement in young patients. The aim is to save good bone stock for a possible revision procedure. Furthermore, there is an increasing demand from young and active patients to receive a new joint which allows a normal or nearly normal life style. With this in mind, we began, in 1993, to develop a new femoral implant. The purpose of this ultra-short stem was a physiologic strain distribution on the proximal femur with a proximal load transfer from the implant to the femoral bone. Main features were an almost complete absence of the diaphyseal portion of the stem, a well defined lateral flare with load transfer on the lateral column of the femur, and a very high femoral neck cut. These innovations resulted in a conservative implant on both the bone stock and the soft tissues. This implant, in the first years, was recommended only for young and active patients. Over the last thirteen years, this project has undergone several modifications but the basic principles of the implant have remained the same. In the present review, we present the rationale, the surgical technique and the clinical and experimental results so far obtained with this implant.  相似文献   
6.
7.
Surgical procedures for the mammary region currently are assuming an important role in body-contouring surgery. Enhancement of results is a constant challenge to the plastic surgeon. A simple and efficient maneuver for resection of the breast’s lateral pole based on the mammoplasty technique of Professor Ivo Pitanguy is described. This study realized at the Private Clinic Sérgio Carreir?o, Rio de Janeiro, RJ, Brazil.  相似文献   
8.
The purpose of this study is to present the results of the arthroscopic treatment of lateral epicondylitis. Twenty patients with lateral epicondylitis (mean age 42 years) were treated arthroscopically. The average duration of symptoms prior to surgery was 14 months. The arthroscopic joint inspection showed an intact capsule in seven patients (type-I lesion), in eight patients a linear capsule tear (type-II lesion) and in six patients a complete rupture of the capsule (type-III lesion). An associated intraarticular pathology was documented in eight patients. Within an average follow-up period of 1.8 years, local pain and function were documented and analyzed. Subjective pain at rest was reduced from 5.0 to 0.5 points, pain at daily living activities from 6.0 to 1.0 points and pain at athletic activities from 7.3 to 1.2 points in the VAS score. Function increased from 5.2 to an average value of 10.9 (max. 12 points). Patients returned back to work after 3.2 weeks. In conclusion, the arthroscopic release in patients with radial epicondylitis is a reproducible method with a marked postoperative increase in function within a short rehabilitation period.  相似文献   
9.
股前外侧区穿支动脉的形态学研究及皮瓣设计   总被引:4,自引:2,他引:2  
目的探讨以旋股外侧动脉降支为蒂的皮瓣设计方法,以便增加术前多普勒定位的准确性。方法6具动脉灌注明胶-氧化铅混悬液的新鲜成人整尸标本,解剖观测股前外侧区穿支,通过血管造影术和拍摄X线片测量其直径、行程、分支和定位。用3D—doctor和Scion Image软件分别测量穿支供血的趋向性、三维重建和单穿支供血面积。结果股前外侧区共有外径大于0.5mm穿支16支,平均外径0.8mm,平均供血面积45.61cm^2,其中20%为肌间隙穿支,80%为肌皮穿支。平均蒂长为(3.15±1.43)cm。自旋股外侧动脉降支发出的穿支在浅筋膜中的平均长度为2.63cm。结论改良的氧化铅-明胶灌注技术可以为皮动脉和穿支皮瓣的研究提供高质量的血管造影图像。本研究发现股前外侧单穿支皮瓣的最大供血面积是30cm×20cm。以股前外侧区穿支设计的穿支皮瓣可以移植到下肢或身体其他部位。  相似文献   
10.
A previously reported paradigm in which rats run down a runway for food reward followed by morphine injection was analyzed to assess the utility of the paradigm in studies of opiate reinforcement. One experiment replicated the original report that post-trial morphine caused both an increase in runway speed and a decrease in food consumption (taste aversion) over successive trials, and showed in addition that the increase in runway speed did not occur as a result of food deprivation alone, but required the animals to have consumed food in the goal box. A second study using the quaternary opiate antagonist methyl naltrexone to block the peripheral effects of morphine suggested that the increase in runway speed has a peripheral locus while the taste aversion has a central one. A third experiment in which morphine was microinjected into either the lateral ventricle or the ventral tegmental area supported these observations, in that intracranial morphine failed to result in an increased runway speed, but did produce taste aversion after microinjection into either site. These findings also suggest that the increase in runway speed caused by post-trial morphine in this experiment has a peripheral locus of effect, which is probably distinct from the central effect that supports morphine self-administration and conditioned place preference. Offprint requests to: W.A.CorrigallThe views expressed in this publication are those of the authors and do not necessarily reflect those of the Addiction Research Foundation  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