Rubidium dicalcium triniobate(V), RbCa(2)Nb(3)O(10), has been synthesized by solid-state reaction and its crystal structure refined from X-ray powder diffraction data using Rietveld analysis. The compound is a three-layer perovskite Dion-Jacobson phase with the perovskite-like slabs derived by termination of the three-dimensional CaNbO(3) perovskite structure along the ab plane. The rubidium io...

In the absence of calcium, the penetration of sucrose and viannitol into the rat lens is increased, while that of inulin remains unchanged. The extracellular space of the lens, estimated with inulin, is 6 per cent of the wet iveight of the lens. The active accumulation of potassium and rubidium is 65 per cent of normal in the absence of calcium, while the uptake of a-aminoisobutyric acid (AIB) ...

Potassium-free artificial sea water causes a loss of cell potassium and a gain of cell sodium in Porphyra perforata, which is not attributable to an inhibition of respiration. On adding KCl or RbCl to such low potassium, high sodium tissues, net accumulation of potassium or rubidium takes place, accompanied by net extrusion of sodium. Rates of potassium or rubidium accumulation and sodium extru...

Valinomycin-induced uptake of rubidium by membrane vesicles prepared from Escherichia coli, Staphylococcus QUreus, and Micrococcus denifrificans is analogous in nearly all respects to the transport of sugars or amino acids, or both, by these membrane vesicles. In E. coli membrane vesicles, concentrative rubidium uptake is stimulated maximally by D-lactate and by the artificial electron donor as...

The effects of extracellular rubidium chloride (1, 2, 4, and 8 HIM) on simultaneously recorded transmembrane action potentials and contractions of human papillary muscle in potassium-free solutions were investigated. In KCl-free solution, reduction in the duration of the action potential at the 25% and 50% levels of repolarization was associated with an increase in the force of contraction. Exp...

1. The midgut contains a 'pool' which must mix with tracer added to the blood-side, before the transported potassium reaches a steady specific activity. The size and mixing time of the pool can be deduced from the time-course of rate of appearance of tracer on the lumen-side, the tracer influx. The theory has been extended to cover cases where the pool-size and the transport rate vary with time...