Laser scanning confocal microscopy combined with fluorescence recovery after photobleaching is an effective tool to measure the diffusion coefficients of macromolecules in cross-linked hydrogels and polymer solutions. In this study, the effects of enzyme treatment on the diffusion of macromolecules (FITC-dextran) in guar solutions and titanium-guar hydrogels are examined. Enzyme treatment with ...

A diagonally implicit method is shown to be an effective method for integrating the multicomponent species conservation equations. The constitutive equation for multicomponent diffusion is recast into a form analogous to that for binary diffusion, except that the diffusion coefficient is replaced with a matrix of effective multicomponent diffusion coefficients. The resulting matrix has properti...

In this paper we revisit the problem of Brownian motion in a tilted periodic potential. We use homogenization theory to derive general formulas for the effective velocity and the effective diffusion tensor that are valid for arbitrary tilts. Furthermore, we obtain power series expansions for the velocity and the diffusion coefficient as functions of the external forcing. Thus, we provide system...

We consider traveling wave solutions of the Korteveg-deVries-Burgers equation and set up an analogy between the spatial averaging of these traveling waves and real-space renormalization for Hamiltonian systems. The result is an effective equation that reproduces means of the unaveraged, highly oscillatory, solution. The averaging enhances the apparent diffusion, creating an "eddy" (or renormali...

We consider many-particle diffusion in 2D colloidal suspensions with hydrodynamic interactions within a mode-coupling approach. We focus on the behaviour of the effective scaled collective diffusion coefficient DC(ρ)/D0 as a function of the density of the colloids ρ, where D0 is the single-particle diffusion coefficient. We find that DC(ρ) is strongly coupled to hydrodynamical conservation laws...

We developed a new pulse sequence and investigated whether the anisotropic diffusion in the human brain can be detailed with a standard whole-body MR imager. Apparent diffusion coefficient maps were produced by the proposed sequence using a 1.5-T MR unit. The sequence employed simultaneous application of three orthogonal gradients to achieve an optimal signal attenuation for imaging the brain w...

Ap effective pore area CAM chorioallantoic membrane CO cardiac output CO2 carbon dioxide dCO2 carbon dioxide diffusion coefficient dH2O water vapor diffusion coefficient dO2 oxygen diffusion coefficient DO2 oxygen diffusing capacity EP external pipping FcOX mean corpuscular oxygenation velocity GCO2 carbon dioxide conductance GH2O water vapor conductance GO2 oxygen conductance Hb hemoglobin Hct...

results a low adc value was associated with lymph node metastasis (p < 0.01) and with high ki-67 protein levels (p = 0.03). there were no significant differences in the adc values among the histological grade (p = 0.48), molecular subtype (p = 0.51), tumor size (p = 0.46), and p53 protein level (p = 0.62). conclusion the pre-operative use of the 3.0 tesla dwi could provide information about the...