Eduardo M. B. Campello^1,2, Tarek I. Zohdi³

CMES-Computer Modeling in Engineering & Sciences, Vol.98, No.2, pp. 221-245, 2014, DOI:10.3970/cmes.2014.098.221

Abstract This work deals with the bombardment of a stream of particles possessing varying mean particle size, velocity and aspect ratio into a cell that has fixed (known) compliance characteristics. The particles are intended to penetrate the cell membrane causing zero or minimum damage and deliver foreign substances (which are attached to their surfaces) to the interior of the cell. We adopt a particle-based (discrete element method) computational model that has been recently developed by the authors to describe both the incoming stream of particles and the cell membrane. By means of parametric numerical simulations, treating… More >

Liqiang Lin¹, Xianqiao Wang², Xiaowei Zeng^1,3

CMES-Computer Modeling in Engineering & Sciences, Vol.98, No.2, pp. 203-220, 2014, DOI:10.3970/cmes.2014.098.203

Abstract The Voronoi tessellation is employed to describe cellular patterns and to simulate cell division and cell remodeling in epithelial tissue. First, Halton sequence is utilized to generate the random generators of Voronoi cell points. The centroidal Voronoi cell center is obtained by probabilistic Lloyd's method and polygonal structure of cell distribution is modeled. Based on the polygonal shape of cells, the instantaneous mechanism of cell division is applied to simulate the cell proliferation and remodeling. Four kinds of single-cell division algorithms are designed with the consideration of cleavage angle. From these simulations, we find that… More >

S.M. Pradhan¹, K.S.Katti¹, D.R. Katti¹

CMES-Computer Modeling in Engineering & Sciences, Vol.98, No.2, pp. 181-201, 2014, DOI:10.3970/cmes.2014.098.181

Abstract Multiscale modeling of collagen fibril is carried out by incorporating the material properties of collagen obtained from steered molecular dynamics into the finite element model of collagen fibril with inclusion of crosslinks. The results indicate that the nonbonded interactions between collagen and mineral contribute to the significant enhancement of the elastic modulus of collagen fibril at all the crosslink densities in both the low strain and high strain regimes. The crosslinks are found to play an important role in the mechanical response of collagen fibril, the enhancement in elastic modulus ranging from 5-11% for various More >

E. P. Yalcintas¹, J. Hu¹, Y. Liu^1,2, A. Voloshin^1,2,3

CMES-Computer Modeling in Engineering & Sciences, Vol.98, No.2, pp. 151-180, 2014, DOI:10.3970/cmes.2014.098.151

Abstract Mechanical behavior of cells plays a crucial role in response to external stimuli and environment. It is very important to elucidate the mechanisms of cellular activities like spreading and alignment as it would shed light on further biological concepts. In this study, a multi-scale computational approach is adopted by modeling the cytoskeleton of cell as a tensegrity structure. The model is based on the complementary force balance between the tension and compression elements, resembling the internal structure of cell cytoskeleton composed of microtubules and actin filaments. The effect of surface topology on strain energy of… More >

J.B. Alford¹, D.C. Simkins¹, R.A. Rembert¹, L. Hoyte, MD²

CMES-Computer Modeling in Engineering & Sciences, Vol.98, No.2, pp. 129-149, 2014, DOI:10.3970/cmes.2014.098.129

Abstract Mechanical deformation of tissues in the female pelvic floor is believed to be central to understanding a number of important aspects of women’s health, particularly pelvic floor dysfunction. A 2008 study of US women reported the prevalence of pelvic floor disorders in the 20 and 39 years range as 9.7% with the prevalence increasing with age until it reaches roughly 50% in the 80 and older age group [Nygaard, Barber, Burgio, and et al (2008)]. Clinical observation indicates a strong correlation between problems such as pelvic organ prolapse/urinary incontinence and vaginal childbirth. It is thought… More >

Louis C. Foucard¹, John Pellegrino¹, Franck J. Vernerey^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.98, No.1, pp. 101-127, 2014, DOI:10.3970/cmes.2014.098.101

Abstract Many colloidal-sized particles encountered in biological and membranebased separation applications can be characterized as soft vesicles such as cells, yeast, viruses and surfactant micelles. The deformation of these vesicles is expected to critically affect permeation by accommodating pore shapes and sizes or enhancing the adhesion with a pore surface. Numerical and theoretical modelings will be critical to fully understand these processes and thus design novel filtration membranes that target, not only size, but deformability as a selection criterion. The present paper therefore introduces a multiscale strategy that enables the determination of the permeability of a… More >

Ankush Aggarwal¹, Jiun-Shyan Chen², William S. Klug³

CMES-Computer Modeling in Engineering & Sciences, Vol.98, No.1, pp. 69-99, 2014, DOI:10.3970/cmes.2014.098.069

Abstract Mechanical properties of proteins play an important role in their biological function. For example, microtubules carry large loads to transport organelles inside the cell, and virus shells undergo changes in shape and mechanical properties during maturation which affect their infectivity. Various theoretical models including continuum elasticity have been applied to study these structural properties, and a significant success has been achieved. But, the previous frameworks lack a connection between the atomic and continuum descriptions. Here this is accomplished through the development of a meshfree framework based on reproducing kernel shape functions for the large deformation… More >

Chu Wang, Lucy T. Zhang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.98, No.1, pp. 41-67, 2014, DOI:10.3970/cmes.2014.098.041

Abstract Bloodstain pattern analysis (BPA) in forensic science is an important tool to solve crime scenes. The complex dynamic behavior of blood drops poses great challenges for accurate fluid dynamic simulations. In this paper, we specifically focus on simulations of blood drop spreading and impact, which may involve contact line hysteresis and spattering of drops as they interact with solid surfaces. Here, we set up a numerical framework that combines (1) the connectivity-free front tracking (CFFT) method for modeling multiphase (air and liquid) flows and (2) a dynamic contact line model for modeling fluid-solid contact line.… More >

R.A. Regueiro^1,2, B. Zhang², S.L. Wozniak³

CMES-Computer Modeling in Engineering & Sciences, Vol.98, No.1, pp. 1-39, 2014, DOI:10.3970/cmes.2014.098.001

Abstract The paper presents three-dimensional, large deformation, coupled finite element analysis (FEA) of dynamic loading on soft biological tissues treated as biphasic (solid-fluid) porous media. An overview is presented of the biphasic solidfluid mixture theory at finite strain, including inertia terms. The solid skeleton is modeled as an isotropic, compressible, hyperelastic material. FEA simulations include: (1) compressive uniaxial strain loading on a column of lung parenchyma with either pore air or water fluid, (2) out-of-plane pressure loading on a thin slab of lung parenchyma with either pore air or water fluid, and (3) pressure loading on More >

K.P. Baxevanakis¹, A.E. Giannakopoulos²

CMES-Computer Modeling in Engineering & Sciences, Vol.97, No.6, pp. 535-544, 2014, DOI:10.3970/cmes.2014.097.535

Abstract This article has no abstract. More >