We developed mathematical models that predict equilibrium distribution of water and electrolytes (proteins and simple ions), metabolites, and other species between plasma and erythrocyte fluids (blood) and interstitial fluid. The models use physicochemical principles of electroneutrality in a fluid compartment and osmotic equilibrium between compartments and transmembrane Donnan relationships f...

A mathematical model has been developed which describes the mass transfer across monovalent-ionpermselective membranes as used in an electrodialysis cell. The mass transfer model is based on the StefanMaxwell transport equations. The latters are derived in the membrane phase with two unstirred layers on each side. Donnan equilibrium is used to describe the concentration and the potential discon...

The synthesis and physicochemical properties of hydrogels with interpenetrated physical chemical networks were considered in relation to their prospective application as biomimetic materials biomedicine bioengineering. study was focused on combined based natural polysaccharide—calcium alginate (CaAlg) a synthetic polymer–polyacrylamide (PAAm). series varying proportions among polyacrylamide hav...

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...

We have studied theoretically the partition equilibrium of a cationic drug between an electrolyte solution and a membrane with pH-dependent fixed charges using an extended Donnan formalism. The aqueous solution within the fixed charge membrane is assumed to be in equilibrium with an external aqueous solution containing six ionic species: the cationic drug (DH(+)), the salt cations (Na(+) and Ca...

1. These experiments confirm the conclusion that protein solutions are true solutions consisting of isolated ions and molecules, and that these solutions may or may not contain in addition solid submicroscopic particles capable of occluding water. 2. The typical influence of electrolytes on the osmotic pressure of protein solutions is due to the isolated protein ions since these alone are capab...

Nguyen, Minhtri K., and Ira Kurtz. Determinants of plasma water sodium concentration as reflected in the Edelman equation: role of osmotic and Gibbs-Donnan equilibrium. Am J Physiol Renal Physiol 286: F828–F837, 2004. First published January 20, 2004; 10.1152/ajprenal.00393.2003.—Edelman et al. have empirically shown that plasma water sodium concentration ([Na ]pw) is equal to 1.11(Nae Ke)/TBW ...

An extension of the stoichiometric displacement (SD) model for the ion-exchange adsorption of dilute proteins is developed which accounts for the effects of hydrogen ion Donnan equilibrium on the protein charge. The ability of the new model to fit retention data when the fluid phase pH is near the protein pI and the effects of hydrogen ion Donnan equilibrium are important is examined using four...