A comparison is made between the quantitative predictions of equilibrium ionic distribution in living cells according to the membrane theory (Donnan equilibrium) and according to the association-induction hypothesis. This comparison shows that both theories predict competitive effects of one permeant ion on the equilibrium concentration of another permeant ion; but within the limit of experimen...

The bioelectric phenomena of excitable tissues involve a complex series of events associated with ionic movements across the labile relative barrier of the cell which is termed the excitable membrane. Present day theories postulate that the resting potential is essentially determined by asymmetry in the distribution of different ions between the interior of the cell and its exterior, that asymm...

The movement of fluid and solutes across biological membranes facilitates the transport of nutrients for living organisms and maintains the fluid and osmotic pressures in biological systems. Understanding the pressure balances across membranes is crucial for studying fluid and electrolyte homeostasis in living systems, and is an area of active research. In this study, a set of enhanced Kedem-Ka...

We consider the Poisson-Boltzmann equation in a periodic cell, representative of a porous medium. It is a model for the electrostatic distribution of N chemical species diluted in a liquid at rest, occupying the pore space with charged solid boundaries. We study the asymptotic behavior of its solution depending on a parameter β which is the square of the ratio between a characteristic pore leng...

Flory Fox, Kurata-Stockmayer, Berry, Inagaki-Suzuki-Kurata, Stockmayer-Fixman and Ahmad-Baloch methods based on the excluded volume theory have been applied to poly(vinyl chloride)-cyclohexanone system to obtain Kq and the radius of gyration. A discussion on the reliability of these methods is given. The Stockmayer-Fixman and Ahmad-Baloch methods are found to be...

We developed an optrode sensing device that utilizes a polymerized colloidal array (PCCA) photonic crystal material. This array diffracts light in the visible spectral region due to the periodic spacing of colloidal particles. The PCCA changes diffraction wavelength due to binding of Pb2+ to an 18-crown-6 ether molecular recognition agent. This optrode consists of a probe assembly that contains...

The Poisson-Boltzmann equation is modified to consider charge ionogenicity, steric exclusion, and charge distribution in order to describe the perimembranous electrostatic potential profile in a manner consistent with the known morphology and biochemical composition of the cell's glycocalyx. Exact numerical and approximate analytical solutions are given for various charge distributions and for ...

An AutoAnalyzer method for serum iron was found to be giving erroneously high values owing to a Donnan equilibrium effect on the rate of dialysis of ferrous ions. The addition of neutral salt to the reagent corrected the deficiency. The validity of other assays on the AutoAnalyzer that measure dialyzable ions in the presence of relatively high concentrations of protein should be verified in vie...