R. Allena^*,†

Molecular & Cellular Biomechanics, Vol.11, No.3, pp. 185-208, 2014, DOI:10.3970/mcb.2014.011.185

Abstract Confined migration is a crucial phenomenon during embryogenesis, immune response and cancer. Here, a two-dimensional finite element model of a HeLa cell migrating across constricted–curved micro-channels is proposed. The cell is modelled as a continuum with embedded cytoplasm and nucleus, which are described by standard Maxwell viscoelastic models. The decomposition of the deformation gradient is employed to define the cyclic active strains of protrusion and contraction, which are synchronized with the adhesion forces between the cell and the substrate. The micro-channels are represented by two rigid walls and exert an additional viscous force on the… More >

S.F. Moreira^∗, J. Belinha^{∗,† ,‡}, L.M.J.S. Dinis^∗,†, R.M. Natal Jorge^∗,†

Molecular & Cellular Biomechanics, Vol.11, No.3, pp. 151-184, 2014, DOI:10.3970/mcb.2014.011.151

Abstract In this work the maxillary central incisor is numerically analysed with an advance discretization technique – Natural Neighbour Radial Point Interpolation Method (NNRPIM). The NNRPIM permits to organically determine the nodal connectivity, which is essential to construct the interpolation functions. The NNRPIM procedure, based uniquely in the computational nodal mesh discretizing the problem domain, allows to obtain autonomously the required integration mesh, permitting to numerically integrate the differential equations ruling the studied physical phenomenon. A numerical analysis of a tooth structure using a meshless method is presented for the first time. A two-dimensional model of More >

Zheng-qi Liu^∗, Ying Liu^∗,†, Tian-tian Liu^∗, Qing-shan Yang^‡

Molecular & Cellular Biomechanics, Vol.11, No.2, pp. 129-149, 2014, DOI:10.3970/mcb.2014.011.129

Abstract In this paper, the hemodynamic characteristics of blood flow and stress distribution in a layered and stenotic aorta are investigated. By introducing symmetrical and unsymmetrical stenosis, the influence of stenosis morphology and stenotic ratio on the coupled dynamic responses of aorta is clarified. In the analysis, the in-vivo pulsatile waveforms and fully fluid–structure interaction (FSI) between the layered elastic aorta and the blood are considered. The results show that the fluid domain is abnormal in the stenotic aorta, and the whirlpool forms at the obstructed and downstream unobstructed regions. The maximum wall shear stresses appear… More >

Hassan P. Modarres^∗, Mohammad R. K. Mofrad^†

Molecular & Cellular Biomechanics, Vol.11, No.1, pp. 39-65, 2014, DOI:10.3970/mcb.2014.011.039

Abstract Focal adhesions are the immediate sites of the cell’s adhesive interaction with the extracellular matrix and as such play a key role in mechanosensing and mechanotransduction at the edge of the cell interface with its surrounding microenvironment. A multitude of proteins orchestrate this mechanochemical communication process between the cell and its outside world. Filamin is a member of focal adhesion protein machinery that also plays a key role in regulating and bundling the acting filament network. A brief review is presented here on filamin and its important protein partners with the aim to shed light More >

Norizadeh Abbariki Tannaz^*,†, Shokrgozar Mohammad Ali^†,‡, Haghighipour Nooshin^*,§, Aghdami Nasser^¶, Mahdian Rezak^II, Amanzadeh Amir^*, Jazayeri Maryam^*,†

Molecular & Cellular Biomechanics, Vol.11, No.1, pp. 19-37, 2014, DOI:10.3970/mcb.2014.011.019

Abstract Background: Environmental factors affect stem cell differentiation. In addition to chemical factors, mechanical signals have been suggested to enhance myogenic differentiation of stem cells. Therefore, this study was undertaken to illustrate and compare the effect of chemical and mechanical stimuli on Myogenin (MyoG) and Myosin heavy chani 2 (Myh2) expression of mouse bone marrowderived mesenchymal stem cells (BMSCs) and embryonic stem cells (ESCs). Methods: After isolation and expansion of BMSCs and generation of embryoid bodies and spontaneous differentiation of ESCs, cells were examined in 4 groups: (1) control group: untreated cells; (2) chemical group: cells… More >

JA. Herzog^∗, TR. Leonard^†, A. Jinha^†, W. Herzog^†,‡

Molecular & Cellular Biomechanics, Vol.11, No.1, pp. 1-17, 2014, DOI:10.3970/mcb.2014.011.001

Abstract Titin is the third most abundant protein in sarcomeres and fulfills a number of mechanical and signaling functions. Specifically, titin is responsible for most of the passive forces in sarcomeres and the passive visco-elastic behaviour of myofibrils and muscles. It has been suggested, based on mechanical testing of isolated titin molecules, that titin is an essentially elastic spring if Ig domain un/refolding is prevented either by working at short titin lengths, prior to any unfolding of Ig domains, or at long sarcomere (and titin) lengths when Ig domain un/refolding is effectively prevented. However, these properties… More >

Rui Fan¹, Dalin Tang^2,3, Jing Yao⁴, Chun Yang⁵, Di Xu⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.99, No.6, pp. 491-508, 2014, DOI:10.3970/cmes.2014.099.491

Abstract Identifying ventricle material properties and its infarct area after heart attack noninvasively is of great important in clinical applications. An echo-based computational modeling approach was proposed to investigate left ventricle (LV) mechanical properties and stress conditions using patient-specific data. Echo data was acquired from one healthy volunteer (male, age: 58) and a male patient (age: 60) who had an acute inferior myocardial infarction one week before echo image acquisition. Standard echocardiograms were obtained using an ultrasound machine (E9, GE Mechanical Systems, Milwaukee, Wisconsin) with a 3V probe and data were segmented for model construction. Finite… More >

Zhuo-Jia Fu¹, Wen Chen^1,2, Jeng-Tzong Chen³, Wen-Zhen Qu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.99, No.5, pp. 417-443, 2014, DOI:10.3970/cmes.2014.099.417

Abstract This study investigates the singular boundary method (SBM) with three regularization approaches for solving 2D and 3D exterior wave problems. The singular boundary method is a recent meshless boundary collocation method, which introduces the concept of source intensity factors to eliminate the singularity of the fundamental solutions. Recently, three approaches, the inverse interpolation technique (IIT), the semi-analytical technique with boundary IIT (SAT1) and the semi-analytical technique with integral mean value (SAT2), have been proposed to determine the source intensity factors for removing the singularities of Helmholtz fundamental solutions at origin. This study compares numerical accuracy… More >

Chein-Shan Liu ¹

CMES-Computer Modeling in Engineering & Sciences, Vol.99, No.5, pp. 371-391, 2014, DOI:10.3970/cmes.2014.099.371

Abstract We recover an unknown initial temperature for a nonlinear heat conduction equation u_t(x,t) = u_xx(x,t) + H(x,t,u,u_x), under the Cauchy boundary conditions specified on the left-boundary. The method in the present paper transforms the Cauchy problem into an inverse heat source problem to find F(x) in T_t(x,t) = T_xx(x,t) + H + F(x). By using the GL(N,R) Lie-group differential algebraic equations (LGDAE) algorithm to integrate the numerical method of lines discretized equations from sideways heat equation, we can fast recover the initial temperature and two boundary conditions on the right-boundary. The accuracy and efficiency are confirmed by comparing the More >

Ş. Emrah Amrahov¹, N. A. Gasilov², A. G. Fatullayev²

CMES-Computer Modeling in Engineering & Sciences, Vol.99, No.5, pp. 351-369, 2014, DOI:10.3970/cmes.2014.099.351

Abstract In this paper, we present a new approach to a time-optimal control problem with uncertainties. The dynamics of the controlled object, expressed by a linear system of differential equations, is assumed to be crisp, while the initial and final phase states are fuzzy sets. We interpret the problem as a set of crisp problems. We introduce a new notion of fuzzy optimal time and transform its calculation to two classical time-optimal control problems with initial and final sets. We examine the proposed approach on an example which is a problem of fuzzy control of mathematical More >