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   11206篇
  免费   1006篇
  国内免费   192篇
耳鼻咽喉   108篇
儿科学   60篇
妇产科学   845篇
基础医学   932篇
口腔科学   356篇
临床医学   1005篇
内科学   447篇
皮肤病学   48篇
神经病学   381篇
特种医学   695篇
外国民族医学   1篇
外科学   2829篇
综合类   1499篇
现状与发展   1篇
预防医学   394篇
眼科学   1321篇
药学   508篇
  11篇
中国医学   564篇
肿瘤学   399篇
  2024年   21篇
  2023年   231篇
  2022年   372篇
  2021年   596篇
  2020年   598篇
  2019年   506篇
  2018年   519篇
  2017年   531篇
  2016年   501篇
  2015年   489篇
  2014年   818篇
  2013年   789篇
  2012年   663篇
  2011年   742篇
  2010年   588篇
  2009年   510篇
  2008年   505篇
  2007年   547篇
  2006年   461篇
  2005年   369篇
  2004年   307篇
  2003年   236篇
  2002年   198篇
  2001年   182篇
  2000年   126篇
  1999年   123篇
  1998年   116篇
  1997年   99篇
  1996年   82篇
  1995年   51篇
  1994年   43篇
  1993年   47篇
  1992年   51篇
  1991年   48篇
  1990年   39篇
  1989年   33篇
  1988年   33篇
  1987年   28篇
  1986年   22篇
  1985年   42篇
  1984年   31篇
  1983年   17篇
  1982年   24篇
  1981年   24篇
  1980年   18篇
  1979年   8篇
  1978年   8篇
  1977年   4篇
  1976年   3篇
  1975年   4篇
排序方式: 共有10000条查询结果,搜索用时 968 毫秒
1.
2.
BackgroundAnteriorly-loaded walking is common in many occupations and may increase fall risk. Dynamic gait stability, defined by the Feasible Stability Region (FSR) theory, quantifies the kinematic relationship between the body’s center of mass (COM) and base of support (BOS). FSR-based dynamic gait stability has been used to evaluate the fall risk.Research questionHow does front load carriage affect dynamic gait stability, step length, and trunk angle among young adults during treadmill walking?MethodsIn this between-subject design study, 30 healthy young adults were evenly randomized into three load groups (0%, 10%, or 20% of body weight). Participants carried their assigned load while walking on a treadmill at a speed of 1.2 m/s. Body kinematics were collected during treadmill walking. Dynamic gait stability (the primary variable) was calculated for two gait events: touchdown and liftoff. Step length and trunk angle were measured as secondary variables. One-way analysis of variance was conducted to detect any group-related differences for all variables. Post-hoc analysis with Bonferroni correction was performed when main group differences were found.ResultsNo significant differences but medium to large effect sizes were found between groups for dynamic gait stability at touchdown (p = 0.194, η2 = 0.114) and liftoff (p = 0.122, η2 = 0.139). Trunk angle significantly increased (indicating backward lean) with the front load at touchdown (p < 0.001, η2 = 0.648) and liftoff (p < 0.001, η2 = 0.543). No significant between-group difference was found related to the step length (p = 0.344, η2 = 0.076).SignificanceCarrying a front load during walking significantly alters the trunk orientation and may change the COM-BOS kinematic relationship and, therefore, fall risk. The findings could inform the design of future studies focusing on the impact of anterior load carriage on fall risk during different locomotion.  相似文献   
3.
BackgroundRocker sole (RS) shoes have been linked to impaired postural control. However, which features of RS design affect balance is unclear.Research questionWhich RS design features affect standing balance and gait stability?MethodsThis study utilized an intervention and cross-over design. Twenty healthy young adults (10 males and 10 females) participated in this study. Standing balance and gait stability were measured using a single force platform and three-dimensional motion analysis system, respectively. The experimental conditions included the control shoe and five RS shoes in the combination of apex position (%) and apex angle (degree) for RS50-95, RS60-95, RS70-95, RS60-70, and RS60-110. The main outcome measures were the area surrounding the maximal rectangular amplitude, mean path length, average displacement of the center of pressure along the lateral and anterior/posterior directions, and maximal center of pressure excursion as the standing balance and lateral margin of stability as the gait stability. Statistical analyses were conducted using a two-way split-plot analysis of variance with repeated measures (with RS design as the within-subject factor and sex as the between-subject factor) and the Bonferroni post hoc test (α = .05).ResultsRegarding the mean path length, RS60-70 was significantly longer than the control shoe, and it showed a significantly increased lateral margin of stability. Thus, RS60-70 was shown to affect standing balance, limit of stability, and gait stability of the frontal plane during gait.SignificanceThese results suggest that the apex angle of the RS design feature affects standing balance and gait stability, and RS60-70 is detrimental to stability. Therefore, when RS with a small apex angle is prescribed, it is necessary to consider the patient’s balance ability.  相似文献   
4.
《Foot and Ankle Surgery》2020,26(2):193-197
BackgroundThe aim of this study was to compare the radiographic and functional results between fixation and non-fixation in the Cotton osteotomy for the treatment of adult acquired flatfoot.MethodsA retrospective, case-controlled study of consecutive stage IIB posterior tibial tendon dysfunction (PTTD) patients treated with the same bony reconstructive surgery including cotton osteotomy between 2013 and 2017. Meary’s angle, the medial arch sag angle (MASA), and medial cuneiform cobb angle (MCCA) were evaluated pre-operation, at first weight bearing after surgery, and 12 months post operation.ResultsForty feet were included in the study. The cotton osteotomy utilized screw fixation (n = 20) or non-fixation technique (n = 20). No significant differences between groups were found in pre-operative and follow-up radiographic parameters, union rate, and functional results.ConclusionThe non-fixation with press fit technique is a reliable procedure for Cotton osteotomy and as effective as screw fixation.Level of evidenceLevel III, case control study  相似文献   
5.
6.
目的 评价调整光学切削直径及Kappa角后对准分子激光原位角膜磨镶术(laser in situ keratomileusis,LASIK)后效果的影响。方法 选取2017年1月至12月在我院行LASIK手术的高度近视患者313例(626眼),根据切削直径分成两组,试验组157例314眼,切削直径设定为6.0 mm,对照组156例312眼,切削直径设定为6.5 mm。试验组患者激光切削前修正Kappa角,对照组不做修正。患者术前进行裸眼视力、主视眼确定、验光、眼压、暗室下瞳孔直径、泪液分泌试验、裂隙灯、散瞳验光、眼底检查、pentacam测量角膜厚度、角膜地形图测量角膜前后表面及Kappa角等检查。术后1 d、1周、1个月随访,并检查裸眼视力、角膜厚度、波前像差及夜间视力、光晕、眩光等情况。比较两组患者角膜厚度变化、手术所用时间以及两组患者术后的高阶像差的差异。结果 试验组与对照组患者年龄分别为18~44(24.19±5.33)岁、18~42(25.08±4.91)岁,屈光度分别为(-7.47±1.04)D、(-7.61±1.12)D。两组年龄、屈光度比较差异均无统计学意义(均为P>0.05)。试验组与对照组患者术前Kappa角分别为,X轴:(210±40)μm、(200±30)μm,Y轴:(190±30)μm、(220±40)μm,差异无统计学意义(P=0.210)。两组手术前后的角膜厚度及术后角膜基质床的厚度差异均无统计学意义(均为P>0.05)。试验组与对照组的手术时间分别为(15.56±1.89)s和(20.83±3.03)s,差异有统计学意义(P=0.000)。试验组的总高阶像差和垂直慧差的变化均明显低于对照组(均为 P<0.01),但两组间的水平慧差差异无统计学意义(P>0.05),对照组的球差低于试验组(P<0.01)。结论 LASIK手术中科学合理地调整Kappa角可有助于提高患者术后的视觉质量。  相似文献   
7.
由于骨盆的特殊结构,其内侧的血管网损伤导致不可压迫性出血。即使创伤中心和救治体系的建设,以及损害控制技术等发展,病死率仍然高达30%~60%。损害控制性复苏、骨盆带、外固定支架、复苏性腹主动脉内球囊阻断(REBOA)、动脉栓塞和腹膜外填塞等技术不断发展,部分已经得到普及,但迄今仍没有公认的确定性止血流程。我国正在普遍建设创伤中心,亟待制订适合我国的骨盆骨折大出血患者的救治流程,以提高救治成功率。本文阐述控制骨盆骨折大出血的外科技术和流程进展供同道参考。  相似文献   
8.
Vestibular function laboratories utilize a multitude of diagnostic instruments to evaluate a dizzy patient. Caloric irrigators, oculomotor stimuli, and rotational chairs produce a stimulus whose accuracy is required for the patient response to be accurate. Careful attention to everything from cleanliness of equipment to threshold adjustments determine on a daily basis if patient data are going to be correct and useful. Instrumentation specifications that change with time such as speed and temperature must periodically be checked using calibrated instruments.  相似文献   
9.
目的 探讨盆筋膜的结构、范围及其与直肠固有筋膜的层次关系。方法 2020年12月至2021年3月对由广东药科大学生命与生物制药学院人体解剖与胚胎学系及中山大学中山医学院人体解剖学教研室提供的12具(男性5具、女性7具)骨盆标本进行大体观察,并对Denonvilliers筋膜进行组织学观察。结合2019年12月至2021年3月中山大学附属第三医院胃肠外科收治的20例直肠癌病人(男性10例、女性10例)的盆腔磁共振图像和手术视频进行解剖学印证。结果 12具骨盆大体标本显示,盆筋膜与Gerota筋膜相延续,部分纤维于S4水平构成直肠骶骨筋膜,向下与直肠固有筋膜融合终止于联合纵肌;部分纤维与后方骶前筋膜融合构成肛提肌上筋膜及肌间纤维。Denonvilliers筋膜在盆腔前外侧约2点、10点处与盆筋膜相延续构成完整筒状结构,包绕内层由直肠固有筋膜封套的直肠系膜;除“侧韧带”处有盆腔自主神经直肠支、淋巴管、直肠中动脉相连外,两层筋膜形成完整的双筒状结构,横断面呈同心圆状。除直肠支进入直肠固有筋膜外,盆腔自主神经主要分支均位于盆筋膜内层及Denonvilliers筋膜以外,沿直肠固有筋膜轮廓游离能够避免损伤盆腔自主神经。在7具女性骨盆标本中均能见到菲薄的Denonvilliers筋膜结构。直肠癌病人的横断面磁共振图像能够看到直肠固有筋膜与外侧盆筋膜、Denonvilliers筋膜的轮廓和间隙,手术视频资料也可见到完整盆壁筋膜和Denonvilliers筋膜的轮廓。结论 直肠癌手术中,在盆筋膜、Denonvilliers筋膜与直肠固有筋膜两层结构的间隙进行分离,并保持两层筋膜的完整性,对于保证肿瘤根治性和保护排尿及性功能至关重要。  相似文献   
10.
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