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   490篇
  免费   28篇
  国内免费   13篇
耳鼻咽喉   3篇
儿科学   9篇
妇产科学   6篇
基础医学   37篇
口腔科学   12篇
临床医学   28篇
内科学   24篇
皮肤病学   11篇
神经病学   10篇
特种医学   10篇
外科学   204篇
综合类   36篇
预防医学   21篇
眼科学   51篇
药学   18篇
中国医学   19篇
肿瘤学   32篇
  2024年   2篇
  2023年   14篇
  2022年   27篇
  2021年   32篇
  2020年   34篇
  2019年   35篇
  2018年   25篇
  2017年   18篇
  2016年   21篇
  2015年   17篇
  2014年   40篇
  2013年   36篇
  2012年   28篇
  2011年   31篇
  2010年   24篇
  2009年   25篇
  2008年   16篇
  2007年   25篇
  2006年   10篇
  2005年   12篇
  2004年   12篇
  2003年   6篇
  2002年   3篇
  2001年   7篇
  2000年   4篇
  1998年   5篇
  1997年   2篇
  1996年   1篇
  1995年   2篇
  1994年   1篇
  1993年   2篇
  1992年   3篇
  1991年   1篇
  1990年   1篇
  1988年   1篇
  1987年   3篇
  1986年   1篇
  1985年   2篇
  1982年   1篇
  1980年   1篇
排序方式: 共有531条查询结果,搜索用时 83 毫秒
1.
《The Journal of arthroplasty》2019,34(8):1711-1717
BackgroundThe declining popularity of cemented acetabular components is incongruous, given the published results of prostheses implanted using contemporary techniques. The outcome of arthroplasty has previously been demonstrated to correlate with surgeon experience and volume of practice. We aim to explore if surgeon volume alters outcomes of cemented acetabular components based on survivorship data from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR).MethodsAn observational study was undertaken using a cohort of 22,956 patients with a primary diagnosis of osteoarthritis in the period 2003-2016 in whom cemented acetabular components were implanted. The cohort was stratified by age (greater than or less than 65 years) and annualized surgical volume of ≤10, >10-≤25, and >25 cases.ResultsStratified by age and volume, there was a protective benefit against revision conveyed at volume thresholds of 10 cases per annum and 25 cases per annum for patients ≥65 years of age and <65 years of age, respectively.ConclusionCemented total hip arthroplasty has excellent survivorship out to 15 years based on AOANJRR data. This survivorship is further improved if surgeons perform a higher volume of cases, with >25 cases conferring the greatest benefit. The AOANJRR data set is used to define best practice; surgeons who choose to utilize cemented acetabular fixation should be encouraged to perform this technique in adequate volumes to minimize revision risk and ensure the preservation of this important surgical skill set.  相似文献   
2.
目的 探讨晕可宁颗粒的主要药效学 ,为临床提供药效学资料及治疗学基础。方法 采用三氯甲烷破坏豚鼠一侧膜迷路感受器模型 ,探讨受试药对眼震颤、摆头及旋转的影响 ;采用内淋巴囊和内淋巴管阻塞手术复制豚鼠膜迷路实验性膜迷路积水模型 ,研究内耳组织平均中阶面积 (SMA)增加率及形态学的变化。结果 抑眩宁阳性对照组、晕可宁颗粒 (8、16g/kg)模型给药组豚鼠眼球震颤次数减少 ,差异有显著意义 (P <0 .0 5 )。成功复制了不同程度膜迷路积水豚鼠模型 ,表现为前庭膜重度膨出 ,前庭阶缩小 ,膜蜗管增大 ,SMA增加率变大 ,差异有显著意义 (P <0 .0 1) ;晕可宁颗粒灌胃后可减轻豚鼠实验性膜迷路积水的程度 ,差异有显著意义 (P <0 .0 1) ;但与空白对照组比较SMA增加率差异无显著意义 (P >0 .0 5 )。结论 晕可宁颗粒可以减轻内淋巴囊积水程度 ,对梅尼埃病症状有对抗治疗作用。  相似文献   
3.
4.
模拟人体体温下对超高分子量聚乙烯(UHMWPE)人工髋臼材料进行了压缩力学性能的试验研究,并与室温下的试验结果进行了对比.当由室温22℃升高到体温37℃和40℃时,其屈服应力呈明显的下降趋势,分别下降了23.1%和31.9%,由体温37℃升高到40℃时,二者仅差3℃,其屈服应力亦下降了11.5%.同时还对不同加载速度下UHMWPE试件压缩变形过程进行了红外辐射温度的监测与分析.不同加载速度下试件压缩变形过程中的红外辐射温度均有明显升高,加载时间越长,试件平均红外辐射温度越高.试验结果分析表明,不能忽视植入人体后UHMWPE人工髋臼局部受压时温度的升高,特别不能忽视植入人体后在人体体温作用下其力学性能的改变和下降,人体体温的作用是UHMWPE人工髋臼出现过早失效的原因之一.本试验研究为UHMWPE材料在人体环境中的应用研究提供了参考.  相似文献   
5.
BackgroundAnterior and posterior pelvic tilt appears to play a role in total hip arthroplasty (THA) stability. When changing from the standing to the sitting position, the pelvis typically rotates posteriorly while the hips flex and this affects the femoro-acetabular positions. This case-control study compares changes in 3-D acetabular cup orientation during functional pelvic tilt between posterior THA dislocations vs stable THAs.MethodsStanding and sitting 3-D cup orientation was compared between fifteen posterior dislocations vs 233 prospectively followed stable THAs. 3-D cup orientation was calculated using previously validated trigonometric algorithms on biplanar radiographs. Those algorithms combine the angles in the three anatomical planes (coronal inclination, transverse version, and sagittal ante-inclination) in the standing position with the change in sagittal pelvic tilt from standing to sitting to calculate the 3-D orientation in the sitting position.ResultsThe standing cup orientation of the dislocated THAs was only characterized by a lower coronal inclination (P = .039). Compared with the controls, from standing to sitting, they showed less posterior pelvic tilt (P < .001). This led to a significant lower coronal inclination (P < .001) and sagittal ante-inclination (P < .001) in the sitting position but similar transverse version (P = .366).ConclusionsComparing posterior THA dislocations to stable THAs, there is a lower increase of all three orientation angles from standing to sitting. This leads to a decreased sitting coronal inclination and sagittal ante-inclination which may lead to an increased risk of impingement ensued by THA instability. By contrast, the transverse version was not significantly different in both positions. This confirms the importance of biplanar data on functional cup orientation.Level of EvidenceDiagnostic, Level III.  相似文献   
6.
《The Journal of arthroplasty》2021,36(10):3527-3533
BackgroundImageless computer navigation improves component placement accuracy in total hip arthroplasty (THA), but variations in the registration process are known to impact final accuracy measurements. We sought to evaluate the registration accuracy of an imageless navigation device during THA performed in the lateral decubitus position.MethodsA prospective, observational study of 94 patients undergoing a primary THA with imageless navigation assistance was conducted. Patient position was registered using 4 planes of reference: the patient’s coronal plane (standard method), the long axis of the surgical table (longitudinal plane), the lumbosacral spine (lumbosacral plane), and the plane intersecting the greater trochanter and glenoid fossa (hip-shoulder plane). Navigation measurements of cup position for each plane were compared to measurements from postoperative radiographs.ResultsMean inclination from radiographs (41.5° ± 5.6°) did not differ significantly from inclination using the coronal plane (40.9° ± 3.9°, P = .39), the hip-shoulder plane (42.4° ± 4.7°, P = .26), or the longitudinal plane (41.2° ± 4.3°, P = .66). Inclination measured using the lumbosacral plane (45.8° ± 4.3°) differed significantly from radiographic measurements (P < .0001). Anteversion measured from radiographs (mean: 26.1° ± 5.4°) did not differ significantly from the hip-shoulder plane (26.6° ± 5.2°, P = .50). All other planes differed significantly from radiographs: coronal (22.6° ± 6.8°, P = .001), lumbosacral (32.5° ± 6.4°, P < .0001), and longitudinal (23.7° ± 5.2°, P < .0001).ConclusionPatient registration using any plane approximating the long axis of the body provided a frame of reference that accurately measured intraoperative cup position. Registration using a plane approximating the hip-shoulder axis, however, provided the most accurate and consistent measurement of acetabular component position.  相似文献   
7.
4种膜组件对黄连解毒汤膜过滤过程的比较研究   总被引:1,自引:0,他引:1  
目的:以中药复方黄连解毒汤为实验对象,比较FMX旋转圆盘平板、中空纤维、管式、过滤杯4种膜组件的膜过滤过程.方法:在相同实验操作条件下,从膜过滤通量、膜阻力分布、指标性成分透过性、膜污染等多个方面,比较4种膜组件对黄连解毒汤的膜过滤情况.结果与结论:FMX、中空纤维、管式膜组件3种动态过滤形式的膜组件比静态死端过滤形式的过滤杯膜组件,在膜通量、膜污染度、指标成分透过性方面具有较为明显的优势;而使流体呈现强烈涡旋状态的FMX膜组件在膜通量、膜污染方面义比管式、中空纤维膜组件具有优势.  相似文献   
8.
Purpose:The current study was aimed at assessment of optic disk by disk damage likelihood scale (DDLS) staging using slit-lamp biomicroscopy and optical coherence tomography (OCT) in diagnosing primary open-angle glaucoma (POAG) patients.Methods:This was a cross-sectional observational study of 106 POAG patients, which was conducted from April 2017 to April 2018. All patients underwent slit-lamp fundoscopy with a +78 D lens and high-definition (HD)-OCT, and the vertical cup disk ratios (VCDRs) were recorded. Disk size and neuroretinal rim assessment were done, and the disk was then staged using the recent version, which stages the optic nerve head (ONH) from 1 to 10 as read from the DDLS nomogram table. DDLS scores >5 indicate glaucomatous damage. Pearson coefficient was used to correlate the DDLS staging by slit-lamp biomicroscopy with best-corrected visual acuity (BCVA), intraocular pressure (IOP), disk size, and VCDR and VCDR, mean deviation, and DDLS staging by HD-OCT.Results:The mean age of the patients was 59.54 ± 6.61 years. The male: female ratio was 2:1. The mean IOP was 16.04 ± 1.97 mmHg, and BCVA was 0.72 ± 0.13 LogMAR units. The mean VCDR on 78 D slit-lamp biomicroscopy was 0.76 ± 0.09 (standard deviation [SD]) (range 0.1–0.77), whereas on HD-OCT, the mean VCDR was 0.81 ± 0.09 (SD) (range 0.07–0.81). The mean deviation on visual field testing in decibels was −14.43 ± 3.31 (SD). The correlation coefficient between DDLS staging by slit-lamp biomicroscopy and DDLS staging by HD-OCT parameters was r = 0.96.Conclusion:There is a positive correlation between the DDLS system of optic disk evaluation on slit-lamp biomicroscopy and most of the HD-OCT evaluation parameters.  相似文献   
9.
目的 探讨肿瘤坏死因子受体相关因子6(TRAF6)对卡介苗(BCG)诱导巨噬细胞凋亡的调控作用。方法 Q-PCR检测活动性结核患者外周血中TRAF6的表达后利用不同感染复数的BCG感染RAW264.7细胞,在感染的不同时间通过Q-PCR和Western blot检测巨噬细胞中Caspase 3和TRAF6的表达。时间梯度试验处理组分为5组:对照组(未感染,C)、BCG感染6 h组、12 h组、18 h组和24 h组;感染复数试验处理组分为5组:对照组(未感染,C)、5 MOI组、10 MOI组、15 MOI组和20 MOI组。随后,通过小干扰RNA技术敲减RAW264.7细胞中TRAF6的表达,并结合BCG感染建立TRAF6敲减模型。TRAF6敲减实验分为4组:阴性对照组(NC)、BCG单独感染组(BCG)、TRAF6小干扰RNA单独处理组(siRNA)和TRAF6小干扰RNA与BCG共处理组(siRNA+BCG)。利用平板涂布法检测巨噬细胞菌载量变化。通过流式细胞术检测巨噬细胞凋亡率和线粒体膜电位变化。利用Western blot检测TRAF6、Caspase 3、PARP、Bcl-...  相似文献   
10.
目的探讨生理性大视杯的遗传规律.方法由同一人用眼底镜检测生理性大视杯家族其他成员的眼底C/D值,分析生理性大视杯的发生率,并用系谱分析法推断生理性大视杯的遗传模式.结果共调查165人,其中生理性大视杯占69.7%.对56个生理性大视杯者家系调查,发现其一级亲中生理性大视杯占53.9%;二级亲中生理性大视杯占57.1%.对有完整双亲的46个生理性大视杯者的父母进行调查,结果发现46个家系中,父母均为生理性大视杯有6个家系,父母均非生理性大视杯有6个家系,仅父亲是生理性大视杯有15个家系,仅母亲是生理性大视杯有19个家系.结论生理性大视杯的发生与遗传有关,可能为常染色体显性遗传.  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