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排序方式: 共有337条查询结果,搜索用时 31 毫秒
1.
ACL和MCL拉伸力学性质实验研究   总被引:20,自引:1,他引:19  
目的 研究了10具新鲜成人尸体膝关节前交叉韧带和内侧副韧带的拉伸力学性质,为临床提供生物力学参数.方法 取正常国人新鲜尸体前交叉韧带和内侧副韧带各20个试样进行单向拉伸实验,得出了破坏载荷、强度极限、最大应变、弹性模量.对实验数据以多项式进行拟合,得出了应力-应变曲线和应力-应变关系表达式.结果 前交叉韧带的拉伸强度极限最大应变弹性模量大于内侧副韧带.  相似文献
2.
Mechanical characterization of collagen-glycosaminoglycan scaffolds   总被引:3,自引:0,他引:3  
Tissue engineering scaffolds are used extensively as three-dimensional analogs of the extracellular matrix (ECM). However, less attention has been paid to characterizing the scaffold microstructure and mechanical properties than to the processing and bioactivity of scaffolds. Collagen-glycosaminoglycan (CG) scaffolds have long been utilized as ECM analogs for the regeneration of skin and are currently being considered for the regeneration of nerve and conjunctiva. Recently a series of CG scaffolds with a uniform pore microstructure has been developed with a range of sizes of equiaxed pores. Experimental characterization and theoretical modeling techniques have previously been used to describe the pore microstructure, specific surface area, cell attachment and permeability of these variants. The results of tensile and compressive tests on these CG scaffolds and of bending tests on the individual struts that define the scaffold network are reported here. The CG scaffold variants exhibited stress-strain behavior characteristic of low-density, open-cell foams with distinct linear elastic, collapse plateau and densification regimes. Scaffolds with equiaxed pores were found to be mechanically isotropic. The independent effects of hydration level, pore size, crosslink density and relative density on the mechanical properties was determined. Independent control over scaffold stiffness and pore size was obtained. Good agreement was observed between experimental results of scaffold mechanical characterization and low-density, open-cell foam model predictions for uniform scaffolds. The characterized scaffold variants provide a standardized framework with defined extracellular environments (microstructure, mechanics) for in vitro studies of the mechanical interactions between cells and scaffolds as well as in vivo tissue engineering studies.  相似文献
3.
老龄深静脉血栓动物模型下腔静脉的力学特性   总被引:2,自引:1,他引:1  
比较正常动物下腔静脉和老龄深静脉血栓动物模型下腔静脉的拉伸力学特性,为临床提供生物力学参数.对正常和各老龄深静脉血栓动物模型20个下腔静脉试样进行拉伸实验,将试样装夹在试验机软组织实验夹具上,以5 mm/min的实验速度对试样施加拉应力,实验环境温度为(36.5±1)%.以回归分析的方法处理实验数据.老龄模型组最大载荷,最大应力/最大位移和最大应变均小于正常对照组,差异显著(P<0.05).拉伸曲线是以指数关系变化的,老龄深静脉血栓对下腔静脉力学特性具有一定影响.  相似文献
4.
Mechanical testing of electrospun PCL fibers   总被引:2,自引:0,他引:2  
Poly(ε-caprolactone) (PCL) fibers ranging from 250 to 700 nm in diameter were produced by electrospinning a polymer tetrahydrofuran/N,N-dimethylformamide solution. The mechanical properties of the fibrous scaffolds and individual fibers were measured by different methods. The Young’s moduli of the scaffolds were determined using macro-tensile testing equipment, whereas single fibers were mechanically tested using a nanoscale three-point bending method, based on atomic force microscopy and force spectroscopy analyses. The modulus obtained by tensile-testing eight different fiber scaffolds was 3.8 ± 0.8 MPa. Assuming that PCL fibers can be described by the bending model of isotropic materials, a Young’s modulus of 3.7 ± 0.7 GPa was determined for single fibers. The difference of three orders of magnitude observed in the moduli of fiber scaffolds vs. single fibers can be explained by the lacunar and random structure of the scaffolds.  相似文献
5.
The adaptability of tendon to loading differs in men and women   总被引:2,自引:0,他引:2  
The reason why women sustain more soft tissue injury than men during physical activity is unknown. Connective tissue properties and extracellular matrix adaptability in human tendon were investigated in models that addressed biochemical, physiological and biomechanical aspects of tendon connective tissue in response to mechanical loading. Habitual training resulted in a larger patellar tendon in men but not in women. Following an acute bout of exercise, men had an elevated tendon collagen synthesis rate and this effect was less pronounced or absent in women. Moreover, levels of circulating oestrogen affected the acute exercise-related increase in collagen synthesis. Finally, the mechanical strength of isolated tendon collagen fascicles in men surpassed that of women. Thus, compared to men, women have (i) an attenuated tendon hypertrophy response to habitual training; (ii) a lower tendon collagen synthesis rate following acute exercise; (iii) a rate of tendon collagen synthesis which is further attenuated with elevated estradiol levels; and (iv) a lower mechanical strength of their tendons. These data indicate that tendons in women have a lower rate of new connective tissue formation, respond less to mechanical loading, and have a lower mechanical strength, which may leave the tissue more susceptible to injury.  相似文献
6.
脊髓损伤继发骨质疏松动物模型骨力学性质实验研究   总被引:2,自引:0,他引:2  
目的 研究正常大鼠骨和脊髓损伤所致大鼠骨质疏松骨力学性质,为临床提供生物力学参数.方法 选用280~320 g,4~5月龄wistar雄性大鼠77只,随机分为0周空白对照组11只,3周对照组11只,7周对照组11只,11周对照组11只,三周实验组11只,7周实验组11只,11周实验组11只.0周空白组于0周处死,解剖取大鼠股骨、胫骨、肱骨,以生理盐水浸温的纱布包裹,置-20℃冰箱内保存备用.对3、7、11周对照组大鼠以咬骨钳将其椎板咬开,不破坏硬膜和脊髓,人为造成脊髓损伤后饲养,复制骨质疏松模型.分别于3、7、11周处死对照组和实验组大鼠.取大鼠股骨进行压缩实验,取肱骨进行剪切实验,取胫骨进行扭转实验.结果 得出了各组大鼠股骨压缩力学性能指标、肱骨剪切力学性能指标和胫骨扭转力学性能指标.结论 实验组和对照组的各项力学性能指标显著低于0周空白组(P<0.05).  相似文献
7.
The new generation of metallic biomaterials for prosthesis implantation (orthopedic and dental) typically have a Ti base with fully biocompatible alloying additions such as Nb, Ta, Zr, Mo, Fe and Sn. While the binary Ti-Ta and the ternary Ti-Nb-Ta systems are promising, the large composition space afforded by these systems offers tremendous scope in terms of alloy design via optimization of alloy composition and thermomechanical treatment. In the present paper a novel combinatorial approach has been developed for rapidly exploring the microstructural evolution and microstructure-microhardness (or elastic modulus) relationships in these systems. Using directed laser deposition, compositionally graded alloy samples have been fabricated and subsequently heat-treated to affect different microstructures in terms of the volume fraction and distribution of the alpha phase in the beta matrix as a function of composition. Subsequently, composition-specific indentation-based hardness and modulus information has been obtained from these graded samples, and the resulting data have been used to develop relationships between the composition, microstructure and mechanical properties. Such rapid combinatorial assessments can be very useful in optimizing not only the alloy composition but also the desired microstructure for achieving the best combination of properties for specific orthopedic or dental applications.  相似文献
8.
环氧改性牦牛心包材料的力学性能   总被引:1,自引:1,他引:0  
本文研究了经新型生物材料交联剂——乙二醇二缩水甘油醚(ethylene diglycidyl ether)处理牦牛心包材料的粘弹性,并与新鲜样品及戊二醛处理样品进行比较。环氧交联剂主要在胶原纤维的分子链间形成交联键,材料的应力松驰速率下降;通过对应力——应变曲线,材料的模量和断裂强度等分析,证明环氧交联剂处理的牦牛心包较用戊二醛处理的有较高的抗张强度和断裂伸长率,并具有一定弹性,作为人工心瓣的瓣叶,在力学性能上是有利的。  相似文献
9.
体内组织工程材料-小肠粘膜下层的力学性能   总被引:1,自引:1,他引:5  
目的对体内组织工程材料-小肠粘膜下层的力学性能进行检测.方法用岛津AG20KNA材料试验机对完成所有处理的SIS进行测试.结果管壁不剖开组的屈服应力为7.72±0.70MPA,应变为42.66±14.69;剖开管壁,平行于管腔纵轴拉伸组的屈服应力为7.57±1.94MPA,应变为42.34±8.29;剖开管壁,垂直于管腔纵轴拉伸组的屈服应力为3.91±0.91MPA,应变为71.59±3.64.结论SIS 在纵轴方向(无论是否剖开管壁)的抗拉强度相当于肌腱和韧带组织的1/7到1/14.SIS具有各向异性的力学特点,无论管壁剖开与否,沿SIS管腔纵轴方向拉伸两组的屈服应力和最大应力比剖开管壁,垂直于管腔纵轴拉伸组的屈服应力和最大应力大两倍.而垂直管腔纵轴拉伸组的屈服应变和最大应变较大,达70%以上.  相似文献
10.
医用Ta5+掺杂TiO2生物薄膜材料的合成与性能研究   总被引:1,自引:1,他引:4  
利用射频控溅射技术合成Ta^5 掺杂的TiO2薄膜材料。采用X射线衍射(XRD)和电子能谱(XPS)等技术对薄膜的成分和结构进行了分析,并利用动态凝血时间测定法和血小板粘附试验研究了薄膜的血液相容性,同时对薄膜的硬度、耐磨性等力学特性进行了研究和评价。结果表明,Ta^5 掺杂的TiO2薄膜不仅具有良好的血液相容性,同时还具有较优的力学耐久性能。  相似文献
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