The chemical diffusion master equation (CDME) describes the probabilistic dynamics of reaction–diffusion systems at molecular level [del Razo et al., Lett. Math. Phys. 112, 49 (2022)]; it can be considered as for processes. CDME consists an infinite ordered family Fokker–Planck equations, where each corresponds to a certain number particles and particle represents molecule. equations describe s...

Translational displacement of molecules within cells is a key process in cellular biology. Molecular motion potentially depends on many factors, including active transport, cytosol viscosity and molecular crowding, tortuosity resulting from cytoskeleton and organelles, and restriction barriers. However, the relative contribution of these factors to molecular motion in the cytoplasm remains poor...

The determination of diffusion coefficients from fluorescence recovery data is often complicated by geometric constraints imposed by the complex shapes of intracellular compartments. To address this issue, diffusion of proteins in the lumen of the endoplasmic reticulum (ER) is studied using cell biological and computational methods. Fluorescence recovery after photobleaching (FRAP) experiments ...

Near ambient pressures, molecular diffusion dominates protonic diffusion in ice. Theoretical studies have predicted that protonic diffusion will dominate at high pressures in ice. We measured the protonic diffusion coefficient for the highest temperature molecular phase of ice VII at 400 kelvin over its entire stable pressure region. The values ranged from 10(-17) to 10(-15) square meters per s...

Gas diffusion in nanoporous carbon includes distinct diffusion modes: surface diffusion on the pore walls and non-surface diffusion away from pore walls. We have performed molecular dynamics (MD) simulations of Ar diffusion in disordered nanoporous carbon. The main objective of this work is to separate the surface diffusion and non-surface diffusion contributions so as to comprehend their respe...

In the membrane method for measuring diffusion coefficients (Northrop and Anson (1928-29)) diffusion takes place through a porous disc. Under these conditions convection currents which usually make diffusion measurements difficult are avoided, the time required for a measurement is greatly shortened, and it becomes possible to remove the diffused substance for estimation. Under suitable conditi...

Diffusion coefficients obtained from weighted mean square displacements along probe molecule trajectories within ultrathin liquid TEHOS films show a correlation with film thickness. By studying cumulative distributions obtained with a time resolution of 20 ms, we could show that the diffusion is heterogeneous within our liquid films which consist of a few molecular layers only. We detected two ...

Objectives Diffusion weighted MRI measures molecular displacements by tagging spins phase according to their posthon, consequently, incoherent displacements cause dephasing, which results in a measurable signal attenuation. Usually, in clinical and biological applications, this incoherent motion is attributed to molecular diffusion (i.e., Brownian motion) within hindered and restricted domains....

A study of the microstructure of polymers is essential for the understanding of their anomalous diffusion properties. The concept of free volume may be utilized to study relaxation phenomena and diffusion processes in polymers. Since a quantitative definition of free volume is not possible, a new concept called available volume is introduced. A simple geometric definition of available volume, r...