We present a novel microscopic tridomain model describing the electrical activity in cardiac tissue with dynamical gap junctions. The system consists of three PDEs modeling conduction intra-and extra-cellular domains, supplemented by nonlinear ODE for dynamics ion channels and establish global existence uniqueness weak solutions to our model. solution, which constitutes main result this paper, ...

in this study, thermo-mechanical nonlinear vibration of a polyethylene (pe) cylindrical shell embedded in an elastic foundation was investigated. the shell is reinforced by armchair carbon nanotubes (cnts) where characteristics of the equivalent composite being determined using mori-tanaka model. the elastic medium is simulated using the spring constant of the winkler-type,  . employing nonline...

A tissue interaction model for skin organ pattern formation is presented. Possible spatially patterned solutions on rectangular domains are investigated. Linear stability analysis suggests that the model can exhibit pattern formation. A weakly nonlinear two-dimensional perturbation analysis is then carried out. This demonstrates that when bifurcation occurs via a simple eigenvalue, patterns suc...

The signal and idler beams from a picosecond, synchronously pumped optical parametric oscillator (OPO) provide the two colors necessary for coherent anti-Stokes Raman scattering (CARS) microscopy. The OPO provides a continuously tunable frequency difference between the two beams over a broad range of Raman shifts (100-3700 cm(-1)) by varying the temperature of a single nonlinear crystal. The ne...

Physically based modeling of deformable objects such as cloth or human tissue has grown to be very important for virtual simulations. However, interactive simulation of these nonlinear deformable objects require high computational power in order to achieve the level of detail and realism required by typical applications. In this paper we introduce a high performance interactive simulation syste...

In this study, a framework for understanding the propagation of stress waves in brain tissue under blast loading has been developed. It was shown that tissue nonlinearity and rate dependence are the key parameters in predicting the mechanical behavior under such loadings, as they determine whether traveling waves could become steeper and eventually evolve into shock discontinuities. To investig...

We present equivalent circuit models of skeletal muscle tissue for the directions parallel and transverse to the fiber. The parallel model is based on a distributed parameter equivalent circuit approach where the tissue between the electrodes is divided into small segments, each of which is represented by an equivalent circuit. Parameters for the equivalent circuits are calculated from the elec...

PURPOSE This paper is the first report on the monitoring of tissue ablation using ultrasound RF echo time series. METHODS We calcuate frequency and time domain features of time series of RF echoes from stationary tissue and transducer, and correlate them with ablated and non-ablated tissue properties. RESULTS We combine these features in a nonlinear classification framework and demonstrate ...

We present a Landau-type theory for the nonlinear elasticity of biopolymer gels with a part of the order parameter describing induced nematic order of fibers in the gel. We attribute the nonlinear elastic behavior of these materials to fiber alignment induced by strain. We suggest an application to contact guidance of cell motility in tissue. We compare our theory to simulation of a disordered ...

This paper presents the estimation methods of subtle hypodense changes of brain tissue in noncontrast CT scans. The purpose of reported research is improved detection of direct signs of hyperacute ischemic stroke. Proposed tool is nonlinear approximation in base of multiscale functions with respective thresholding. Different rationales for best basis selection were considered. Several local bas...