Riccardo Sacco

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  Modeling and Simulation of Ion Flow in Biological Channels Including Electrochemical, Fluid, Thermal and Mechanical Forces
  Riccardo Sacco
  In this communication we propose a multiphysics model for the simulation of biological ion channels using a continuum-based approach that self-consistently combines ion electrodiffusion, channel fluid motion, thermal self-heating and mechanical deformation. The mathematical formulation consists of a system of nonlinearly coupled partial differential equations in conservation form that includes: the thermo-velocity-extended Poisson-Nernst-Planck equations; the Stokes equations; the Navier-Lame' equations; and the heat equation.
  
  Extensive computational examples are illustrated to provide a validation of models and methods in the simulation of two realistic channel geometries under quite different operation regimes. In the first case study we consider a cylindrical voltage operated ion nanochannel transporting K+ and Na+ ions. In the second case study we consider the interplay between the motion of K+, Na+, Cl- and HCO-_3 ions and the active secretion of aqueous humor across the (non-pigmented) epithelial cells of the ciliary body in the eye. Obtained results are in very good agreement with available experimental data and biophysical conjectures.