Defect-controlled softness, diffusive permeability, and mesh-topology of metallo-supramolecular hydrogels

In a model 4-arm pEG supramolecular network, connectivity defects are systematically introduced with different ratios of 8-arm pEG, resulting in intra-molecular loops, and providing a softer polymer network and higher self-diffusion coefficients.

Простая теория многокомпонентной диффузии и моделирование горения стехиометрической смеси H-=SUB=-2-=/SUB=-/O-=SUB=-2-=/SUB=-

A theory of multicomponent diffusion based on Fick's law is proposed, where, when writing the Maxwell-Stephen equations, a multicomponent mixture is represented as consisting of two components: the isolated substance and all the others with average characteristics. The number of diffusion coefficients is significantly reduced, the method for their calculation is indicated, and they strongly depend on the concentration of the mixture components. Based on the results of this theory, the combustion of an H2/O2 mixture with an equivalence ratio equal to unity was simulated. For each component, great chemical work is carried out with alternating signs, but in total they partially destroy each other. Also, in the chemical reaction zone, there is a strong change in the stoichiometric ratio of the H2 and O2 components.

Regression Analysis of Confocal FRAP And Its Application To Diffusion In Membranes

In most biological processes, diffusion plays a critical role in transferring various bio-molecules to transfer desirable locations in an effective and energy-efficient manner. How fast molecules are transferred is measured by diffusion coefficients. Since each bio-molecules, in particular, signaling molecules have their unique diffusion coefficients and quantifying the diffusion coefficients help us to understand various time scales of both physiological and pathological processes in biological systems. Moreover, since diffusion profiles of a diffusant vary in different micro-environments of cell membranes, accurate diffusion coefficient also can provide a good picture of membrane landscapes as well as interactions of different membrane constituents. Currently, only a few experimental methods are available to assess the diffusion coefficient of a biomolecule of interest in live cells including Fluorescence Recovery After Photobleaching (FRAP). FRAP was developed to study diffusion processes of biomolecules in the cell membranes in the 1970s. Albeit its long history, the main principle of FRAP analysis has remained unchanged since its inception: fitting FRAP data to a theoretical diffusion model for the best fitting diffusion coefficient or using the relation between the half time of recovery and ROI size. In this study, we developed a flexible yet versatile confocal FRAP data analysis framework based on linear regression analysis which allows FRAP users to determine the diffusion from either single or multiple FRAP data points without data fitting. We also validated this approach for a series of fluorescently labeled soluble and membrane-bound proteins and lipids.