ductance of layer. These dependencies showed that hybridization appears when sheet conductance of layer (σ) exceeds some critical value σcr), the magnitude of which changes in wide range and depends on material and plate orientation. For example, for aforementioned hybrid pair A0 SH0 in potassium niobate σcr = 10−3S. If σ < σcr modes are not coupled, i.e. their dispersion curves do not repulse....

Background We aimed to describe urinary sodium and potassium excretion and their ratio in a representative sample of Portuguese elderly population, according to sociodemographic characteristics and weight status. Methods A cluster sampling approach was used, representing older Portuguese adults (≥65 years) according to age, sex, education level, and regional area within the Nutrition UP 65 st...

One-dimensional potassium niobate nanowires are of interest as building blocks in integrated piezoelectric devices, exhibiting large nonlinear optical and piezoelectric responses. Here we present femtosecond measurements of light-induced polarization dynamics within an optically trapped ferroelectric nanowire, using the second-order nonlinear susceptibility as a real-time structural probe. Larg...

We report the generation of complex soliton-like patterns in noncritically-phase-matched potassium niobate which occur in random spatial patterns from shot-to-shot. Up to five spots have been generated at input intensities of 10's GW/cm2, many times the single soliton threshold. The mechanism which leads to the symmetry breaking required for the complex patterns is interpreted to be random nois...

The stationary intracellular potassium concentration in E. coli B 525 has been studied as a function of the extracellular potassium and sodium concentrations. The ratio of extracellular to intracellular potassium concentration is shown to be a linear function of the extracellular potassium concentration if the extracellular sodium concentration is low (20 mmoles/1). In the case of high sodium c...

Nanoparticles of potassium tantalate (KTaO3) and potassium niobate (KNbO3) were synthesized by oxidation of metallic tantalum in molten potassium nitrate with the addition of potassium hydroxide. Magnetization curves obtained on these ferroelectric nanoparticles exhibit a weak ferromagnetism, while these compounds are nonmagnetic in a bulk. The experimental data are used as a start point for th...

The interactions of potassium ions and ATP on transport ATPase activity are discussed, and the interpretation of these interactions is shown to be often ambiguous. Caldwell's (1968) Physiological Review model is discussed with particular reference to the observed kinetics of sodium: sodium exchange in red cells. Recent experimental work on the properties of the ouabain-sensitive component of po...

Estimates of initial binding rates for [3H]ouabain interaction with (Na+ + K+)-ATPase were obtained in the presence of ATP, magnesium, sodium, and potassium by using short assay times at 30”. The reactions were terminated by the rapid addition of excess unlabeled ouabain; this did not appear to displace bound [3H]ouabain during subsequent treatment of the suspensions (prior to assay). Initial b...