The recent controversy over whether the photon diffusion coefficient depends on absorption is addressed by use of the analytical solution of the photon transport equation in an infinite homogeneous scattering medium. The diffusion coefficient is found to be independent of absorption but temporally dependent. After a long period of time, the photon diffusion coefficient approaches D=1/3mu(s)(?) ...

Diffusion-weighted magnetic resonance imaging data obtained early in the course of therapy can be used to estimate tumor proliferation rates, and the estimated rates can be used to predict tumor cellularity at the conclusion of therapy. Six patients underwent diffusion-weighted magnetic resonance imaging immediately before, after one cycle, and after all cycles of neoadjuvant chemotherapy. Appa...

BACKGROUND AND PURPOSE The aim of this study was to measure apparent diffusion coefficients in rat brain tissue exposed to ouabain, glutamate, and N-methyl-D-aspartate and to compare them with apparent diffusion coefficients found in acute cerebral ischemia. METHODS The apparent diffusion coefficient was measured using magnetic resonance microscopy in four groups of Sprague-Dawley rats after ...

As the technology of enhanced oil recovery by gas injection has already been applied worldwide, the research of the transmit mechanism between injected-gas and oil is important to the optimization of gas injection plan. Diffusion is an important phenomenon during the process of gas injection displacement. Because of diffusion, gas molecules will penetrate into the oil phase, while the oil will ...

Oxygen diffusion in polymer membranes has great significances on the choice of packaging materials. In this work, molecular dynamics simulations and Grand canonical Monte Carlo were used to study the diffusion of oxygen in polymer membranes. It is found that the diffusion coefficient of oxygen in polymer membranes increases as the temperature increases. And the diffusion coefficient of oxygen i...

To research rumor diffusion in social friend network, based on interests, a dynamic friend network is proposed, which has the characteristics of clustering and community, and a diffusion model is also proposed. With this friend network and rumor diffusion model, based on the zombie-city model, some simulation experiments to analyze the characteristics of rumor diffusion in social friend network...

Abstract. Dynamical zeta functions provide a powerful method to analyze low dimensional dynamical systems when the underlying symbolic dynamics is under control. On the other hand even simple one dimensional maps can show an intricate structure of the grammar rules that may lead to a non smooth dependence of global observable on parameters changes. A paradigmatic example is the fractal diffusio...

OBJECTIVE To assess the feasibility and reliability of apparent diffusion coefficient (ADC) measurements of normal adrenal glands. MATERIALS AND METHODS This was a retrospective study involving 32 healthy subjects, divided into two groups: prepubertal (PreP, n = 12), aged from 2 months to 12.5 years (4 males; 8 females); and postpubertal (PostP, n = 20), aged from 11.9 to 61 years (5 males; 1...