黄伟;刘有军;主海文;刁越;高松
试验背景骨是一种非均匀各向异性材料,它和其它材料一样具有自己的各种材料属性.人们已经在这方面做了不少工作,但目前有关国人股骨和胫骨不同方向的力学参数尚很少见,人们在进行有限元计算时常采用各向同性假设.我们测试了国人的股骨和胫骨不同方向的屈服强度、破坏强度、弹性模量和大压缩拉伸比.并做它们的应力松弛试验,将试验结果记录曲线用对数函数拟合,得到应力松弛时力与时间的关系.
作者:王勃;陈孟诗;樊瑜波 刊期: 2003年第z1期
Limitations in the size and amount of bone tissue produced in vitro via tissue engineering are mainly due to the lack of nutrient and oxygen supply to the cells some distance away from the surface. Our laboratory has investigated possibilities for growing bulky bone tissue using novel hollow fibre bioreactors. The hollow fibre membranes embedded in the three dimensional scaffold are porous and semi permeable, which can serve the function of arteries and veins.
作者:Hua YE;Zhidao XIA;David J. P. FERGUSON;James T. TRIFFITT;Zhangfeng CUI 刊期: 2003年第z1期
Neutrophil activation and adhesion play important roles in many inflammatory processes, but their importance in both acute pancreatitis (AP) and pancreatitis- associated microcirculatory derangements has not been defined.The aim was to better understand flow -induced the changes of [ Ca2+ ]i, the polymerization of filamentous actin( F -actin),the expression of (2 -intgrin(CD18) and L- selectin(CD62L) on neutrophil in pancreatic microcirculation of AP.
作者:Zongguang ZHOU;Youqin CHEN;Yongyang YU;Huaiqing CHEN 刊期: 2003年第z1期
Objective To explore the characteristics of the dynamic change in postburn erythrocyte membrane viscoelasticity and its influence on the regional myocardial blood flow.
作者:Qingyun WU;Xiang WANG;Xiangdong LUO 刊期: 2003年第z1期
心脏是推动血液循环的动力泵,临床上常常使用射血分数(EF)、大氧耗量等指标评估心脏的功能,但这些指标中并未包含反映心脏负荷特征的压强,因此,这些指标的局限性是显而易见的.从力学的观点看,功或功率是客观反映一个动力泵能力的指标.多年来,很多学者使用压力与流量的积表示心脏的做功能力,但该指标只与心脏对外做功能力有关,并不能完全说明心脏的做功特性.本文提出了一种与心脏平均功率相关的指标:
作者:张建保;袁利君;张晓军;刘一辉;曹铁生 刊期: 2003年第z1期
1.流体切应力对内皮细胞形态的影响:人脐静脉内皮细胞(HUVECs)被流体切应力38、75dyne/cm2作用12小时后,内皮细胞被拉长,长轴与流场方向一致,内皮细胞的拉长、定向程度和切应力大小、作用时间的长短有关.细胞内F-actin的排列方向也与切应力方向一致.
作者:陈槐卿 刊期: 2003年第z1期
切应力可调节细胞的增殖和凋亡,从而影响血管的重建.研究低切应力对完整血管平滑肌细胞原癌基因蛋白c-Fos和c-Myc表达的影响,可以初步探讨切应力引起血管平滑肌细胞增殖和调亡的机制.本文应用血管体外应力培养系统,将一段完整的猪颈总动脉在体外进行培养,控制定常流和血管腔内压力100mmHg,在中(20dyn/cm2)、低(5dyn/cm2)切应力条件下体外培养1、6、24h,采用免疫组化和计算机图象分析方法观察血管壁平滑肌细胞c-Fos和c-Myc表达的情况.
作者:姜宗来;刘艳春;刘波;张峰;张炎 刊期: 2003年第z1期
经支气管动脉灌注(Bronchial Artery Infusion,BAI)药物的肺癌介入治疗方法,具有创伤小、疗效好、毒副作用低、恢复快等优点.随着医学影像技术、计算机技术、生物制药技术、临床外科技术等的进步,肺癌介入治疗技术得到了迅速发展和推广.但是它的发展还是受到多种因素的影响,诸如:穿刺点血肿和出血;大血管破裂;导管易断裂,由于支气管动脉很细,大多在1~3mm左右,寻找支气管动脉入口较为困难;其它并发症,如股动脉阻塞、肋间动脉炎导致皮肤损害等,尤为严重的是脊髓损伤,高位截瘫并发症,国外发生率为1.5%~5.0%,国内发生率约为1.5%~12%.虽然高位截瘫发生率不高,但后果严重.
作者:吴效明;岑人经;贺继刚;袁支润 刊期: 2003年第z1期
微载体悬浮培养是贴壁细胞的一种常见培养方式,在大多数传统的生物反应器中一般都有搅拌装置,这样会带来较高的剪切力并且极易导致湍流,容易使待培养的细胞受到损伤.
作者:鞠智好;刘天庆;崔占峰;马学虎 刊期: 2003年第z1期
青光眼是国家防盲工作的重点,闭角型青光眼是其中的主要类型,致盲率很高,瞳孔阻滞形成和虹膜组织材料变性是发病的主要体征.近百年的研究没有给出虹膜材料力学特性的定量表达和瞳孔阻滞力的量化描写.主要原因是虹膜材料试样小、中有瞳孔,待测力学量小,无法进行常规测量.我们开发了瞳孔水密缝合构建虹膜腔体进行测量的实验方法.
作者:刘志成;林丁;宋红芳;张昆亚;乔春燕 刊期: 2003年第z1期
Introduction The wedge - shaped cervical lesion, generally characterizing with wedgelike shape and frequently subgingival location, is the loss of tooth structure at the neck of a tooth. It may be caused mainly by occlusal stress. The association between cervical lesions and occlusal attritions had been studied by some researchers. In the clinical diagnoses, authors observed that the wedge - shaped cervical lesions had different orientations. The lesions point to the coronal ( CL), the middle (ML) and the root (RL) of tooth, respectively.
作者:Bo HUO;Qing ZHANG;Jiade WANG 刊期: 2003年第z1期
Introduction The researches show that a realistic three - dimensional biodynamic model of the human leg is developing into powerful tools for functional analysis of the knee, for evaluation of surgical and diagnostic procedures, and for design of artificial joint[1,2]. In the other word, if it could be established, then it may become possible to accurately obtain the muscle,ligament, and the articular contact forces at the human knee joint in vivo with the aid of biodynamic simulation. This, without doubt, will provide a powerful way for the clinic rehabilitation. But, unfortunately, so far this work is still challenging for biomechanical/biomedical researchers.
作者:Xishi WANG;Liqun ZHANG;Tianying WANG 刊期: 2003年第z1期
Introduetion In human dentin,microscopic tubules extend through the entire dentin with variational diameters.The peritubular dentin encircles the tubules and is characterized by its high mineral content.The intertubular dentin occupies the volume outside of peritubular dentin and contains more collagen and less mineral than the peritubular dentin.The above structural characters of dentin should lead to an inhomogeneous and anisotropic stress-strain relation of dentin.In the past years,a lot of experiments based on the microscopic structure of dentin had been done.Some attempts on theoreticallv modeling constitutive law of dentin were also presented.Here author gives an inhomogeneous and anisotropic constitutive model of human dentin,considering the difference of peri-and intertubular dentin,and compare the FEA results basing on this model with the moiréfringe testing results of Wang and Weiner(1998).
作者:Bo HUO 刊期: 2003年第z1期
The decline of cardiac contractility is a serious outcome of heart failure, and therefore, the measurement and evaluation of cardiac contractility and its reserve is of great clinical significance. However, there are at least two problems in this aspect:( 1 ) the concept of cardiac contractility has serious defects, including the absence of any potential indicator that can be measured in situ and is free of significant criticism and, particular, the absence of any acceptable noninvasive indicator, and the impossibility of separating the effects of contractility changes from those of load or heart rate; (2) the requirement of the telemetering of cardiac contractility for the patients, athletes, and ordinary persons has not been met.
作者:Shouzhong XIAO 刊期: 2003年第z1期
Understanding of the biomechanics of human foot and ankle complex can help in designing a better foot support. Experimental approaches are limited to interfacial pressure measurement between the foot and supporting surface and gross motion tracking of major foot joints. The measurement of internal stress/strain and individual bony movement of the foot and ankle,which is essential in enhancing knowledge on the biomechanics of the foot, is still sparse due to experimental difficulties. Computer simulation provides an efficient alternative to acquire those important clinical parameters.
作者:Ming ZHANG;Jason Tak - Man CHEUNG;Yubo FAN 刊期: 2003年第z1期
实验设备与用材1.视频维度分析仪系统(VDA)该系统是由电视摄象机、电视录象机、视频维度分析仪、监视器、带条记录仪组成,电视摄象机用于记录兔下肢股静脉长度的变化,然后将信号分别传到电视录象机和视频维度分析仪,电视录象机将所拍摄的信号存储起来,视频维度分析仪可将视频信号加以分析,以获得其长度的变化,变化的情况可由监视器来观察,带条记录仪可将应变与时间的关系曲线绘制出来.
作者:冯岱雅 刊期: 2003年第z1期
本文的目的是利用定量的骨功能适应性模型建立一种描述骨质疏松的力学模型.目前国内外,尤其是国外,对于骨质疏松的研究很多,但大都集中在药物对骨质疏松的治疗,通常以骨质疏松结构的生化指标为研究对象,对骨质疏松进行的实验研究较多,建立定量模型的基础性理论研究还未见报道.
作者:宫赫;朱兴华 刊期: 2003年第z1期
脑部动脉环(Willis环)中血液的动力学特征和脑血管疾病之间有着密切的联系.两侧大脑前动脉(AA)由前交通动脉(ACA)相连接,大脑中动脉(MA)、大脑后动脉(PA)由后交通动脉(PCA)使之沟通,型成脑循环的Willis环.通过合理建立力学模型可以帮助医学工作者更加准确的认识疾病,提高有关疾病诊断的正确率.血液动力学模型主要可以分为使用传统的流体力学方程进行数值求解的分布参数模型和使用点卢比你流体参量的集中参数模型.后者由于计算简洁、力学量的意义明确而受到越来越多的关注.
作者:陈书宇;丁光宏 刊期: 2003年第z1期
Introduction It is well known that the deformation of an adherent leukocyte plays a critical role in response to external mechanical forces, but it remains to be elucidated that if it's nucleus deforms with cell deformation. Studies using parallel flow chambers, radial flow assays show that the stiffness of leukocyte increases when cells are allowed to spread or after adaptation to flow,both conditions being associated with a remodeling of the cytoskeleton ( Dong and Lei, 2000). However, most of these models are based on the hypothesis that the leukocyte is a solid sphere.
作者:Xiaoheng LIU;Xiong WANG;Hua HUANG 刊期: 2003年第z1期
目前,关于腰椎间盘的结构形态与力学性能的研究,多侧重于整体的力学性能和微观组织结构方面.有关纤维层水平的结构形态及力学性能研究尚未见系统报道.本文是对腰椎间盘纤维环纤维层水平的结构形态和力学性能进行比较系统的研究,为间盘本身及相关疾病研究提供理论依据,为人工替代材料、组织工程提供参考数据.
作者:朱东 刊期: 2003年第z1期