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Finite Element Analysis of Muscular Contractions from DC Pulses in the Liver

G. Long, D. Plescia, and P. Shires
Ethicon Endo-Surgery, Cincinnati, OH, USA

Thermal ablation of malignant tumors has been conducted in patients who are not candidates for surgery for more than ten years. Recently it has been shown that low energy DC pulses can cause cell necrosis. An undesirable characteristic of DC pulses in-vivo is the stimulation of skeletal muscle. The intensity of the contraction depends in part on the duration and height of the pulse. Through the ...

Simulation of Transport of Lipophilic Compounds in Complex Cell Geometry

Q.A. Chaudhry[1], M. Hanke[1], and R. Morgenstern[2]
[1]School of Computer Science and Communication, Royal Institute of Technology, Stockholm, Sweden
[2]Karolinska Institutet, Stockholm, Sweden

The mathematical modeling of the diffusion and reaction of toxic compounds in mammalian cells is tough task due to their very complex geometry. The heterogeneity of the cell, particularly the cytoplasm, and the variation of the cellular architecture, greatly affects the behavior of these toxic compounds. Homogenization techniques have been implemented for the numerical treatment of the model. ...

Comparison of Computational Methods for the Estimation of the Dielectrophoretic Force Acting on Biological Cells and Aggregates in Silicon Lab-on-chip

S. Burgarella[1], F. Maggioni[2], and G. Naldi[2]
[1]STMicroelectronics, Agrate Brianza, Milan, Italy
[2]Department of Mathematics, University of Milan, Milan, Italy

Dielectrophoresis is a method for cell manipulation in miniaturized devices exploiting the dielectric properties of cells and/or cellular aggregates suspended in a fluid and subjected to a high-gradient electric field. The mathematical expression of the force is obtained by a multipole expansion whose terms involve increasing power of the particle\'s radius. Three methods for the expression ...

A Method for Efficient Calculation of Diffusion and Reactions of Lipophilic Compounds in Complex Cell Geometry

Kristian Dreij[1], Qasim Ali Chaudhry[2], Bengt Jernström[1], Ralf Morgenstern[1], and Michael Hanke[2]
[1]Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
[2]School of Computer Science and Communication, Royal Institute of Technology, Stockholm, Sweden

A general description of effects of toxic compounds in mammalian cells is facing several problems. Firstly, most toxic compounds are hydrophobic and partition phenomena strongly influence their behaviour. Secondly, cells display considerable heterogeneity regarding the presence, activity and distribution of enzymes participating in the metabolism of foreign compounds i.e. bioactivation ...

Simulation of Deformed Solid Particles in Constrained Microfluidic Channel

M. Cartas-Ayala[1], R. Karnik[1]
[1]Massachusetts Institute of Technology, Cambridge, MA, USA

Characterization of particles has numerous applications in science and diagnostics. Recently, particle passage through constrained microchannels has been proposed to characterize particles based on their passage velocity. Nevertheless, there is no clear understanding of how the physics in this system interact. Here we quantify the effects of the flow around the particle by simulating the passage ...

Singlet Oxygen Modeling of BPD Mediated-PDT Using COMSOL

T.C. Zhu[1], B. Liu[1], X. Liang[1]
[1]University of Pennsylvania, Philadelphia, PA, USA

Singlet oxygen (1O2) is the major cytotoxic agent during photodynamic therapy (PDT). A previously developed model that incorporates the diffusion equation for the light transport in tissue and the macroscopic kinetic equations for the generation of the singlet oxygen, can be used to numerically calculate the distance-dependent reacted 1O2 using finite-element method (FEM). The formula of reacted ...

Large Scale Invasion Of New Species And Of Genetic Information

O. Richter, F. Suhling, and S. Moenickes
Technische Universität Braunschweig, Germany

The spatial dynamics of the invasion of new species and genetic dispersal is studied under the presumption of rising temperature by using a coherent approach of coupled partial differential equations of the reaction diffusion type. The nonlinear reaction terms model the population dynamics, genetic exchange and competition. Temperature reaction norms of reproduction rates are conferred by a two ...

Modeling Bacterial Clearance Using Stochastic-Differential Equations

A. Jeremic, and A. Atalla
McMaster University, Hamilton, ON, Canada

In this paper, we develop a mathematical model to simulate the movement of bacteria into and within a capillary segment. Also, we model the transportation through capillary walls by means of anisotropic diffusivity that depends on the pressure difference across the capillary walls. By solving the model using COMSOL, it was possible to predict the concentration of bacteria at points within the ...

Extending Engineering Simulations to Scientists: Food Safety and Quality Prediction Using COMSOL Multiphysics® and LiveLink™ for Excel®

A. Warning[1], A. K. Datta[1]
[1]Cornell University, Ithaca, NY, USA

The objective of this study was to develop an easy to use interface in Excel® that connects to not only the solvers in COMSOL Multiphysics®, but also existing databases of food properties, foodborne pathogenic microorganisms kinetics, and chemical kinetics, creating a comprehensive simulation software to predict food safety and quality. The user interface allows the user to select the food, ...

Modeling Plant Morphodynamics in Predefined COMSOL Multiphysics® Interface

S. Nikolaev[1], A. Trubuil[2]
[1]Institute of cytology and genetics SB RAS, Novosibirsk, Russia
[2]Institut National de la Recherche Agronomique, Jouy-en-Josas, France

We used a predefined COMSOL Multiphysics® interface to imitate biological growth and shape change (morphodynamics). We found a set of parameters that supply observed morphodynamics for an Arabidopsis embryo during its transition from globular to heart stage.