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Wei Huang^∗,†, Yi Wah Mak^*, Peter C. Y. Chen^‡§
Molecular & Cellular Biomechanics, Vol.8, No.2, pp. 91-104, 2011, DOI:10.3970/mcb.2011.008.091
Abstract A molecular configuration tensor Pij was introduced to analyze the distribution of fibrous proteins in vascular cells for studying cells and tissues biomechanics. We have used this technique to study the biomechanics of vascular remodeling in response to the changes of blood pressure and flow. In this paper, the remodeling of the geometrical arrangement of F-actin fibers in the smooth muscle cells in rat's pulmonary arteries in hypoxic hypertension was studied. The rats were exposed to a hypoxia condition of 10% for 0, 2, 12, and 24 hr at sea level. Remodeling of blood vessels… More >

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Wei Huang^∗,†, Qinlian Zhou^†,‡, Jian Gao^‡, R. T. Yen^‡,§,¶
Molecular & Cellular Biomechanics, Vol.8, No.2, pp. 105-122, 2011, DOI:10.3970/mcb.2011.008.105
Abstract A continuum model was introduced to analyze the pressure-flow relationship for steady flow in human pulmonary circulation. The continuum approach was based on the principles of continuum mechanics in conjunction with detailed measurement of vascular geometry, vascular elasticity and blood rheology. The pulmonary arteries and veins were considered as elastic tubes and the "fifth-power law" was used to describe the pressure-flow relationship. For pulmonary capillaries, the "sheet-flow" theory was employed and the pressure-flow relationship was represented by the "fourth-power law". In this paper, the pressure-flow relationship for the whole pulmonary circulation and the longitudinal pressure More >

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D.D. D’Lima^*, P.C. Chen^†, O. Kessler^‡, H.R. Hoenecke^*, C.W. Colwell Jr.^∗§
Molecular & Cellular Biomechanics, Vol.8, No.2, pp. 123-134, 2011, DOI:10.3970/mcb.2011.008.123
Abstract The menisci are important biomechanical components of the knee. We developed and validated a finite element model of meniscal replacement to assess the effect of surgical fixation technique on contact behavior and knee stability. The geometry of femoral and tibial articular cartilage and menisci was segmented from magnetic resonance images of a normal cadaver knee using MIMICS (Materialise, Leuven, Belgium). A finite element mesh was generated using HyperWorks (Altair Inc, Santa Ana, CA). A finite element solver (Abaqus v6.9, Simulia, Providence, RI) was used to compute contact area and stresses under axial loading and to… More >

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1148

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P.C. Chen^∗,†, C.W. Colwell^†, D.D. D’Lima^†,‡
Molecular & Cellular Biomechanics, Vol.8, No.2, pp. 135-148, 2011, DOI:10.3970/mcb.2011.008.135
Abstract A nonlinear viscoelastic finite element model of ultra-high molecular weight polyethylene (UHMWPE) was developed in this study. Eight cylindrical specimens were machined from ram extruded UHMWPE bar stock (GUR 1020) and tested under constant compression at 7% strain for 100 sec. The stress strain data during the initial ramp up to 7% strain was utilized to model the "instantaneous" stress-strain response using a Mooney-Rivlin material model. The viscoelastic behavior was modeled using the time-dependent relaxation in stress seen after the initial maximum stress was achieved using a stored energy formulation. A cylindrical model of similar… More >

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Ramana M. Pidaparti^∗,†, Kittisak Koombua^∗,‡
Molecular & Cellular Biomechanics, Vol.8, No.2, pp. 149-168, 2011, DOI:10.3970/mcb.2011.008.149
Abstract Better understanding of the stress/strain environment in airway tissues is very important in order to avoid lung injuries for patients undergoing mechanical ventilation for treatment of respiratory problems. Airway tissue strains responsible for stressing the lung's fiber network and rupturing the lung due to compliant airways are very difficult to measure experimentally. A computational model that incorporates the heterogeneity of the airways was developed to study the effects of airway tissue material properties on strain distributions within each layer of the airway wall. The geometry and boundary conditions of the tissue strain analysis were obtained More >

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