The transport of macromolecules across the renal glomerular capillary wall has been described theoretically using flux equations based on (a) restricted transport through small pores, and (b) the Kedem-Katchalsky formulation. The various assumptions and limitations inherent in these two approaches are discussed. To examine the coupling between macromolecular solute transport and the determinant...

Transport in porous media is quite complex, and still yields occasional surprises. In geological porous media, the rate at which chemical reactions (e.g., weathering and dissolution) occur is found to diminish by orders of magnitude with increasing time or distance. The temporal rates of laboratory experiments and field observations differ, and extrapolating from laboratory experiments (in mont...

8 9 The objective of this work is to discuss solute transport phenomena in fractured porous 10 media, where the macroscopic transport of contaminants in the highly permeable inter11 connected fractures can be strongly affected by solute exchange with the porous rock 12 matrix. We are interested in a wide range of rock types, with matrix hydraulic 13 conductivities varying from almost impermeabl...

Transport of solutes through brain involves diffusion and convection. The importance of convective flow in the subarachnoid and paravascular spaces has long been recognized; a recently proposed 'glymphatic' clearance mechanism additionally suggests that aquaporin-4 (AQP4) water channels facilitate convective transport through brain parenchyma. Here, the major experimental underpinnings of the g...

A mathematical solution for solute transport in a three-dimensional porous medium with a patch source under steady-state, uniform ground water flow conditions was developed by Domenico (1987). The solution derivation strategy used an approximate approach to solve the boundary value problem, resulting in a nonexact solution. Variations of the Domenico (1987) solution are incorporated into the so...

More ecient methods are needed for the in situ evaluation of solute sorption to aquifer sediments. The objective of this study was to develop a simpli®ed method for estimating retardation factors for injected solutes from ``push±pull'' test extraction phase breakthrough curves (BTCs). Sensitivity analyses based on numerical simulations were used to evaluate the method performance for a variety...

A mathematical model of solute transient diffusion across the cornea to the anterior chamber of the eye was developed for topical drug delivery. Solute bioavailability was predicted given solute molecular radius and octanol-to-water distribution coefficient (Phi), ocular membrane ultrastructural parameters, tear fluid hydrodynamics, as well as solute distribution volume (Vd) and clearance rate ...

BACKGROUND AND OBJECTIVES Insulin resistance has been associated with cardiovascular disease in peritoneal dialysis patients. Few studies have addressed the impact of fast transport status or dialysis prescription on insulin resistance. The aim of this study was to test whether insulin resistance is associated with obesity parameters, peritoneal transport rate, and glucose absorption. DESIGN,...

The objectives of this study were to: (i) examine the efficacy of two sampling techniques for characterizing solute transport under steady-state water flow, (ii) study the variation in transport model parameters with increasing depth of solute leaching, and (iii) perform model discrimination to examine the transport process operative within a field plot. Bromide, NO?, and Clwere applied sequent...

The contributions of mechanisms by which chelators influence metal translocation to plant shoot tissues are analyzed using a combination of numerical modelling and physical experiments. The model distinguishes between apoplastic and symplastic pathways of water and solute movement. It also includes the barrier effects of the endodermis and plasma membrane. Simulations are used to assess transpo...