A dual-pathway model is proposed for transport across the tight junction (TJ) in rat proximal tubule: large slit breaks formed by infrequent discontinuities in the TJ complex and numerous small circular pores, with spacing similar to that of claudin-2. This dual-pathway model is developed in the context of a proximal tubule model (Weinstein AM. Am J Physiol Renal Fluid Electrolyte Physiol 247: ...

BACKGROUND Increasing cell membrane permeability to water and cryoprotectants is critical for the successful cryopreservation of cells with large volumes. Artificial expression of water-selective aquaporins or aquaglyceroporins (GLPs), such as mammalian aquaporin-3 (AQP3), enhances cell permeability to water and cryoprotectants, but it is known that AQP3-mediated water and solute permeation is ...

Caveolae are invaginated membrane structures with high levels of cholesterol, sphingomyelin, and caveolin protein that are predicted to exist as liquid-ordered domains with low water permeability. We isolated a caveolae-enriched membrane fraction without detergents from rat lung and characterized its permeability properties to nonelectrolytes and protons. Membrane permeability to water was 2.85...

for better understanding the effect of nanofluid flow in a porous medium, a set of experiments were conducted on a horizontal glass micromodel for al2o3-water nanofluids. to characterize the flow of nanofluids the same experiment was done by pure water. the glass micromodel was constructed by a photolithography technique. the al2o3-water nanofluids were produced by a two-step method and no surf...

A comprehensive experimental investigation has been conducted to determine the effective permeability of fluid saturated porous media consisting of small and large spherical particles. Small and large particles were mixed uniformly at a certain mixture ratio so as to form a vertical porous column. Water was drawn from a reservoir to flow through the vertical tube filled with particles of differ...

Naturally occurring pores show a variety of polarities and sizes that are presumably directly linked to their biological function. Many biological channels are selective toward permeants similar or smaller in size than water molecules, and therefore their pores operate in the regime of single-file water pores. Intrinsic factors affecting water permeability through such pores include the channel...

The mechanisms by which fluid moves across the luminal membrane of cholangiocyte epithelia are uncertain. Previous studies suggested that aquaporin-1 (AQP1) is an important determinant of water movement in rat cholangiocytes and that cyclic AMP mediates the movement of these water channels from cytoplasm to apical membrane, thereby increasing the osmotic water permeability. To test this possibi...

The relationship of freezing resistance to water permeability of cortex cells was studied in stems of red osier dogwood (Cornus stolonifera Michx.). Permeability was estimated by determining the diffusion flux of tritiated water from cortex slices previously equilibrated in tritiated water. Energy of activation and diffusion time comparisons of tritiated water flux from living cortex slices and...

the effects of zinc oxide nanorod (zno-n) incorporation on thephysicochemical properties of tapioca starch / bovin gelatin composite film such as water absorption capacity (wаc), water solubility and permeability to water vapour (wvp) were investigated. in this search, zno-n was homogenized by sonication and added into tapioca starch / bovine gelаtin dispersions аt different concentrations (e.g...

Porous concrete is a mixture of cement and water that may contain fine grains, which play a role in water transfer and permeability. Porous concrete can act as a drain to pass rainwater and recharge groundwater. In this study, 25%, 50%, 75%, and 100% zeolite were used to replace the coarse aggregates in porous concrete. The effects of the zeolite on the compressive strength, permeability coeffi...