The effects of Naþ, Kþ, Caþþ and Mgþþ cations on the sol–gel transitions of high acyl (HA) gellan dispersions were investigated. Gelling temperatures of 1% HA gellan dispersions containing selected cations (monovalent cations, 10–200 mM; divalent cations, 2–80 mM) were determined using dynamic rheological analysis. Gelling temperatures increased with cation concentrations. Divalent cations exhi...

We specify the black box behavior of data ow components by characterizing the relation between the input and the output histories We distinguish between three main classes of such speci cations namely time independent speci cations weakly time dependent speci cations and strongly time dependent speci cations Data ow components are semantically modeled by sets of timed stream processing function...

The interaction of a series of alkylamines with muscle pyruvate kinase was investigated by kinetic and physical studies in order to understand the mechanisms by which certain monovalent cations can activate the enzyme and to define several of the important conformational changes necessary for catalytic activity. Monomethylammonium ion interacts with pyruvate kinase to activate the enzyme. Dimet...

K+ is required for the stimulation by the antibiotic nigericin of adenosine triphosphate hydrolysis in rat liver mitochondria. This action does not occur when K+ is replaced by other monovalent cations. It requires slightly hypotonic conditions and is not related to the swelling phenomena linked to the accumulation of K+ in mitochondria. ATPase is inhibited by small anion molecules to which the...

K+ is required for the stimulation by the antibiotic nigericin of adenosine triphosphate hydrolysis in rat liver mitochondria. This action does not occur when K+ is replaced by other monovalent cations. It requires slightly hypotonic conditions and is not related to the swelling phenomena linked to the accumulation of K+ in mitochondria. ATPase is inhibited by small anion molecules to which the...

The effect of interactions of various Ia and IIa cations with two positions of the adenine-thymine (A−T) and guanine-cytosine (G−C) base pairs on the geometries and individual hydrogen bond (HB) energies have been investigated by using the atoms in molecules (AIM) method at the B3LYP/6-311++G(d,p) level of theory. The cations that possess higher charge/radius (q/rad) ratio make higher changes o...

The aim of this study was to develop an extended-release tablet formulation using a new in situ cross-linking method. The effects of polyvalent cations on theophylline release from tablets made with the polyanionic polymers sodium alginate and sodium carboxymethylcellulose, were investigated. Different miliequivalents of the di and tri-valent cation, Ca2+ and Al3+, were added to tablet form...