Using unfertilized eggs of Arbacia punctulata as natural osmometers an attempt has been made to account for the course of swelling and shrinking of these cells in anisotonic solutions by means of the laws governing osmosis and diffusion. The method employed has been to compute permeability of the cell to water, as measured by the rate of volume change per unit of cell surface per unit of osmoti...

Solution is developed for the build!up\ steady and post!arrest dissipative pore ~uid pressure _elds that develop around a conical penetrometer advanced in a poroelastic medium[ The analog with cone penetrometer testing is direct\ and is used to enable continuous distributions of permeability and di}usivity to be determined\ with depth[ Solution for a point normal dislocation migrating in a poro...

Effects of the diuretic ethacrynic acid on osmotic water permeability were investigated in the isolated perfused collecting tubule of the rabbit kidney. The base-line water permeability of the collecting tubule was not affected when the drug (10(-4)M) alone was added to the bathing medium. Vasopressin alone in the bathing medium (2, 5 muU/ml) elicited a significant increase in osmotic water abs...

Polyacrylonitrile (PAN) membranes with nano-porous surface and high hydrophilicity were fabricated by addition of polyoxyethylene (40) nonylphenyl ether (IGEPAL) as an additive in the casting solution. The membranes were prepared from PAN/IGEPAL/1-Methyl-2-pyrrolidone (NMP) via phase inversion induced by immersion precipitation technique. Pure water was used as coagulation medium. The effects o...

Practical design parameters of resonant metamaterials, such as loss tangent, are derived in terms of the quality factor Q of the resonant effective medium permeability or permittivity. Through electromagnetic simulations of loopbased resonant particles, it is also shown that the Q of the effective medium response is essentially equal to the Q of an individual resonant particle. Thus, by measuri...

L cells have a resting potential of about -16 mv (internal negative) at 37 degrees C in Dulbecco's modified Eagle's medium containing 10% fetal calf serum and a potassium concentration of 5.4 mM. Membrane resistivity is about 20,000 ohmcm(2) when the surface filopodia described by others are taken into account. Mechanical and electrical stimuli can evoke an active response from mouse L cells, c...

To determine if histamine acts directly on the vascular endothelium, the effect of histamine on the permeability of cultured human endothelial cell monolayers and the role of second messengers were examined. The addition of 10(-6) to 10(-4) M histamine to the culture medium decreased the endothelial cell monolayer permeability and increased both cyclic AMP and free-calcium levels. The decrease ...

The hepatic blood circulation is complex, particularly at the microcirculatory level. Previously, 2D liver lobule models using porous media and a 3D model using real sinusoidal geometries have been developed. We extended these models to investigate the role of vascular septa (VS) and anisotropic permeability. The lobule was modelled as a hexagonal prism (with or without VS) and the tissue was t...

A passive, matched two-time-derivative Lorentz material medium is designed to have its equivalent permittivity and permeability smaller than their values in free space over a large range of frequencies. Superluminal pulse propagation in this medium and consequent superluminal information exchange without a violation in causality are demonstrated. Additional properties of this medium are develop...