-
Fallesen Gold posted an update 1 year, 5 months ago
A mathematical model, in the form of a system of nonlinear ordinary differential equations, that describes the interaction between tumor cells and effective immune cells is proposed. An exact solution cannot be found to this system like many other nonlinear systems. Yet, approximate analytical solution is explored. This solution should have a large interval of convergence to be acceptable because the interaction can take many days to reach its steady state. Power series method is used to obtain a series solution. In this process, some auxiliary variables are used to transform the system of equations to polynomial form. However, this solution has a small radius of convergence, therefore, Padé approximant method is used to extend the domain of convergence. Hence, the obtained approximate analytical solution is valid over a large interval and has a remarkable accuracy when compared with numerical solution.Modeling cardiac cell electrophysiology relies on fitting model equations to experimental data obtained under voltage/current clamping conditions. The fitting procedure for these often-nonlinear ionic current equations are mostly executed by trial-and-error by hand or by gradient-based optimization approaches. These methods, though sometimes sufficient at converging at optimal solutions is based on the premise that the characteristic objective function is convex, which often does not apply to cardiac model equations. Meta-heuristic methods, such as evolutionary algorithms and particle swarm algorithms, have proven resilient against early convergence to local optima and saddle-point parameter solutions. This work presents a genetic algorithm-based approach for fitting the adult cardiomyocyte biophysical model formulations to the experimental data obtained in human induced pluripotent stem cell-derived cardiomyocyte (hiPSC-CM). Specifically, whole-cell patch clamp ionic current data of rapid delayed rectifier potassium current, IKr, transient outward potassium current, Ito and hyperpolarization-activated current, If, was used for fitting. Using a two-point crossover scheme along with initial population and mutation constraints randomly selected from a uniformly distributed constrained parameter space, near-optimal fitting was achieved with R2 values (n = 5) of 0.9960±0.0007, 0.9995±0.0002, and 0.9974±0.0014 for IKr, Ito and If respectively.We have recently postulated that certain bacterial cells within their biofilms are equipped with electrically-polarized and elastic helical fibers called amyloid fibrils which allow the cells to transmit electromagnetic (EM) signal to their surrounding environment through mechanical vibration of these fibrils. A novel and theoretical Multiphysics model based on a coupled system of electrical and mechanical structures is proposed here enabling prediction of efficient signal generation in the radio frequency range among the cells. Next, to demonstrate the advantage of EM-based communication, using communication channel theory, we have compared performance of EM signaling with its biochemical counterpart (quorum sensing) and shown that EM signaling provides much higher data rate, 4 to 5 orders of magnitude. Thus, it could be potentially more efficient and a preferred method for communication among cells. Ivacaftor cost In quorum sensing, biological cells release auto-inducers intercepted by the adjacent cells as a purposeful message signal.Cancer is a complex disease that continues to pose formidable challenges to therapeutic interventions. An increased understanding of cancer complexity and in particular tumor growth dynamics is critical to the development of more effective therapies. In this respect, an agent-based model of tumor growth is explored with the consideration of cancer reprograming of metabolism and the immune response, to seek insight about the coupling between these two key determinants of tumor growth dynamics. Ultimately, this exploration is intended to inform the development of therapies that can induce a more effective immune response despite the metabolic constraints of the tumor microenvironment.A mathematically identical ordinary differential equations (ODEs) model was derived from a multiscale partial differential equations (PDEs) model of hepatitis c virus infection, which helps to overcome the limitations of the PDE model in clinical data analysis. We have discussed about basic properties of the system and found the basic reproduction number of the system. A condition for the local stability of the uninfected and the infected steady states is presented. The local stability analysis of the model shows that the system is asymptotically stable at the disease-free equilibrium point when the basic reproduction number is less than one. When the basic reproduction number is greater than one endemic equilibrium point exists, and the local stability analysis proves that this point is asymptotically stable. Numerical sensitivity analysis based on model parameters is performed and therefore the result describes the influence of each parameter on the basic reproduction number.The application of nanomedicine for diagnosis and treatment of cancer has immense potential, but has witnessed only limited clinical success, in part due to insufficient understanding of the role of nanomaterial properties and physiological variables in governing nanoparticle (NP) pharmacology. Here, we present a multiscale mathematical model to examine the effects of physiological changes associated with patient age on the pharmacokinetics and tumor delivery efficiency of NPs. We show that physiological changes due to aging prolong the residence of NPs in the systemic circulation, thereby improving passive accumulation of NPs in tumors.Clinical Relevance – Understanding the effect of inter-individual variability on the pharmacological behavior of nanomaterials will improve their clinical translatability.Galvanic vestibular stimulation (GVS) involves the application of electrical current through electrodes placed exclusively at the mastoids or in combination with electrodes placed on other regions. It is a simple, safe modality to modulate and probe vestibular function. Despite a long history of use, it continues to be primarily used as a research tool with no fully developed therapeutic use. This is partly due to the fact that to further advance this technique, a better understanding of what structures are stimulated and by how much is needed. While models have been proposed to explain response, cellular and structural substrates confirmed empirically, the exact current flow pattern has not been investigated.The goal of this study is to therefore determine current flow patterns in GVS. In order to do so, we developed the first ultrahigh-resolution finite element model of GVS incorporating the tiny structures of interest in the inner ear. We simulated the Bilateral-Bipolar, Bilateral-Monopolar, and the Unilateral-Monopolar configurations.

