Xiannong CHEN;Fugang WANG
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 coupling between the endothelium and blood flow is an important biomedical problem and has drawn extensive research. Endothelial cells (ECs) are known to adapt their shapes and functions in response to applied shear flow.Shear Stress being regarded as a primary triggering signal for cellular remodeling, it is important to understand the interaction mechanism between applied shear flow and endothelial cells.
作者:Xiaoheng LIU;Xiong WANG;Huaiqing CHEN 刊期: 2003年第z1期
Do the tension、compress and bend test on the normal and morbid femoral head cancellous bone and do the stress relaxation and creep test on the lognitudinal and the transverse samples. Then compare the mechanical natures of the normal and the morbid femoral head's cancellous bone. The object of this research is to offer the basic theory for the research of artificial joint material、the design of artificial joint、the implantation of artificial femoral head and the bone's creation and rebuilding.
作者:Hongshun MA;Hai ZHANG 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
静脉移植术中被移植到动脉环境下的静脉桥血管的重建问题一直受到人们的广泛关注.手术后在动脉高压环境下,静脉血管段扩张;而在吻合口处则容易由于缝线或者外科损伤引起的急性凝血形成局部的僵硬和狭窄.这都引发血液流动情况异常,使血管所处的力学环境发生特异性变化.力学因素中影响血管重建的主要是粘性血液流动所引起的壁面切应力和血管壁所承受的周向张应力.桥血管中切应力分布的信息对血管病理学研究十分必要.由于至今很难直接检测活体血管壁上的切应力分布,因而本文致力于建立力学模型,用可以无创伤检测的力学参量(近心端动脉血管轴心处的轴向流速波形和管壁径向位移波形、血管壁的几何方程)来获取血管内壁上切应力分布的数值结果.
作者:孙辉;龚克勤;柳兆荣 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
Mechano - chemical coupling is a common phenomenon that exists in various biological processes at different physiological levels. Bone tissue remodeling strongly depends on the local mechanical load. Leukocytes are sheared to form the transient aggregates with platelets or other leukocytes in the circulation. Flow pattern affects the signal transduction pathways in endothelial cells. Receptor/ligand interactions are important to cell adhesion since they supply the physical linkages among cells. How external forces influence the biological function has little been known, and nowadays attract more and more attentions. Here the forced dissociation of selectin/ligand binding is used to test mechano - chemical coupling at molecular level.
作者:Mian Long 刊期: 2003年第z1期
骨整合(osseointegration)的概念初是由Branemark于20世纪50年代提出,是指活骨组织与种植体在结构上和功能上的直接结合.从生理角度来看,骨整合形成后,骨组织与种植体之间不存在纤维性组织,而只存在骨性连接.基于骨整合的植入式假肢与传统的接受腔式假肢相比有显著的优越性,如病人更容易控制假肢的活动,以及病人肢体残端不会出现压疮等.然而,对于下肢假肢种植体,载荷对骨整合影响的生物力学问题尚缺乏深入、系统的研究.本文对骨整合形成初期,种植体在较大生理载荷(体重量级)和外部载荷情况下的骨整合发展,进行了初步的动物实验研究.
作者:修凯华;王勃;雷文涛;董骧;陈孟诗;樊瑜波 刊期: 2003年第z1期
前言在体动脉的内皮细胞暴露于血流中,同时承受着血流产生的壁切应力(WSS)和血压导致的周向应力(CS)的作用.在体或离体的研究表明,血流切应力和周向应力与内皮细胞的结构和功能密切相关.但绝大部分研究都是研究血流切应力或周向应力对内皮细胞的单独作用.由于在体动脉中血流和血压不是孤立存在的,它们之间存在着联系,因之产生的血流切应力和血管周向应力不是孤立地对内皮细胞起作用,而是联合地起作用.已有的在体实验结果表明,低流体切应力和高周向应力的联合作用与动脉粥样硬化紧密相关.
作者:覃开蓉;柳兆荣;Akira KAMIYA;Joji ANDO 刊期: 2003年第z1期
髋臼骨折属于严重的内关节骨折,由于解剖结构复杂,创伤程度重,治疗难度大,是临床治疗的热点和难点.目前手术前的诊断和分型主要依靠对CT扫描片的分析.对髋臼骨折的生物力学分析也主要集中在对尸体标本进行机械受力分析上,所得到的数据较少.
作者:陈学强;吴建国;苏佳灿 刊期: 2003年第z1期
细胞的迁移是细胞生长的一个重要特性,细胞在材料上的迁移情况在一定程度上表征了材料的生物相容性和组织修复能力.本研究对成骨细胞在聚乳酸材料上的迁移特性进行了考察.
作者:潘君;王远亮 刊期: 2003年第z1期
为探讨压力在血管重建中的作用,观察了不同静压力条件下,体外培养动脉中层平滑肌细胞的形态学变化、增殖与凋亡及其相关蛋白的变化趋向.本文选用成年雄性金华猪颈总动脉4~7cm,在不同静压力(160mmHg、100mmHg)下培养1、4、7天(控制血管内流体流量≤6ml/h)后,4%多聚甲醛固定,以新鲜血管为对照组,血管常规石蜡切片后,应用HE染色、免疫组织化学、TUNEL、Hoechst33258荧光染色、透射电镜等方法进行观察.
作者:张峰;张炎;刘波;刘艳春;姜宗来 刊期: 2003年第z1期
Receptor/ligand interactions are basic issues to cell adhesion, which are important to many physiological and pathological processes such as lymphocyte-mediated cytotoxicity ,tumor metastasis and inflammatory reactionl.
作者:Jun HUANG;Juan CHEN;Mian LONG 刊期: 2003年第z1期
肿瘤抑制因子PTEN(Phosphatase and TENsion homology deleted on chromosome 10)是新近发现的具有磷脂磷酸酶和蛋白磷酸酶双重活性的磷酸酶.人体的多种肿瘤与PTEN基因突变有关.PTEN参与多种细胞增生、迁移、粘附、凋亡、细胞周期等功能的调控.然而,PTEN对心血管系统作用的研究却甚少,它是否参与了应力介导的动脉重建尚未见报道.本文旨在观察血管紧张素转换酶抑制剂卡普托利对高血压大鼠主动脉PTEN mRNA表达的影响,探讨PTEN是否参与了高血压动脉重建.
作者:严志强;胡亚娥;刘波;姜宗来 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
本研究对猪肝门静脉的生物力学特性与月龄间的关系进行了探讨,为猪→人异种肝移植提供力学资料.取1~6月龄正常猪肝门静脉36例,利用软组织力学试验机测定其压力-直径关系数据,计算出血管各向同性增量弹性模量(Einc)、压力-应变弹性模量(Ep)、容积弹性模量(Ev)和顺应性(Compliance).
作者:王配军;李文春;孙万群;黄铁柱 刊期: 2003年第z1期
目的对牙的动力学研究的基础是模态分析.随着计算机技术的高速发展,有限元法的应用领域得到进一步的拓展,可以实现对生成计算模型的物体进行各种力学分析.本研究应用有限元分析软件MARC对上颌中切牙的模型进行模态分析,以期了解其振动性能.
作者:李明勇;马轩祥;李玉龙;李斌;赵令诚 刊期: 2003年第z1期
2001年王世强等人把膜片钳技术和激光扫描共聚焦显微成像技术结合起来,首次记录到心肌细胞内由单个L型钙通道分子产生的局部钙信号,将其命名为Ca2+sparklet(钙星).实验结果证明单个钙通道开启所形成的钙星可触发单个钙火花,参与钙致钙释放的L型钙通道和RyR相距仅12~15纳米.
作者:谭文长;刘世强;郭晶晶;程和平 刊期: 2003年第z1期
目的肌腱缺损的修复与功能重建是骨外科的研究重点之一.组织工程化肌腱为修复肌腱缺损开辟了一条新途径.它具有良好的生物相容性、生物活性、生物力学相容性并能诱导胶原生成.近年来,在组织工程化肌腱方面已开展了多方面的研究,初步临床应用也取得了较好的效果.但是,从组织工程化肌腱的研究和应用中发现,它在植入体内后,其抗拉强度始终达不到正常肌腱的数值.不难推断,材料在体内的降解速率及诱导生成的胶原纤维的数量和质量同新生肌腱的生物力学性能有密切关系.
作者:秦廷武;张姝江;杨志明;李秀群 刊期: 2003年第z1期
More and more evidences come out to support that the functionality of adhesion molecules are influenced by the surface microtopology of cell carrier or substrate. Adhesive molecules usually express on the microvilli of a cell, providing a well - defined spatial configuration to mediate the adhesions to the counterpart molecules on the apposed surface. In a pioneering work,comparisons were done by using immunoglobin (IgG) binding to their counterpart receptors CD16 expressed onto the membrane of transfected K562 cells (rough surfaces) and coated onto the surface of human red blood cells (smooth surfaces), respectively[1]. Here we extended this idea by developing a biomembrane force probe to elucidate the effect of surface microtopology and membrane stiffness on the kinetics of selectin/ligand binding.
作者:Botao shaw;Mian long 刊期: 2003年第z1期