The relationship between high-temperature superconductivity and the fractional quantum Hall effect

The case is made that the spin-liquid state of a Mott insulator, hypothesized to exist by Anderson and identified by him as the correct context for discussing high-temperature superconductors, occurs in these materials and exhibits the principles of fractional quantization identified in the fractional quantum Hall effect. The most important of these is that particles carrying a fraction of an elementary quantum number, in this case spin, attract one another by a powerful gauge force, which can lead to a new kind of superconductivity. The temperature scale for the superconductivity is set by an energy gap in the spin-wave spectrum, which is also the fundamental measure of how "liquid" the spins are.     

Levels of selenium in blood and tissues associated with some selenium deficiency diseases in New Zealand sheep

Whole bloods from weaned lambs with severe selenium responsive unthriftiness usually contain <5 ng Se/ml. Mildly or moderately affected lambs have blood levels of 5-10 ng/ml. Selenium responsive infertility in ewes appears to be associated with whole blood selenium levels below 10 ng/ml.     

Endogenous ionic currents traverse intact and damaged bone

Living bone drives an electric current through itself and into sites of damage. Such "fracture currents" consist of two components: an intense, decaying current dependent on bone deformation and a stable, persistent current driven by a cellular battery. The latter is carried by chloride ions and, to a lesser extent, by sodium, magnesium, and calcium ions. Endogenous fracture currents are of the same polarity and similar magnitude as clinically applied currents that are successful in treating chronic nonunions in fractured bones. This suggests that the defect in biological nonunions may reside in the electrophysiology of repair.     

Validation of liquid chromatographic method for assay of calcitriol and alfacalcidol in capsule formulations

The validation of a liquid chromatographic procedure suitable for the determination of calcitriol and alfacalcidol in their respective formulations labeled to contain at least 0.25 micrograms drug per unit is described. The capsule content is diluted and chromatographed in 15-20 min on silica columns (5 micron) with a mobile phase of hexane-tetrahydrofuran-methylene dichloride-isopropanol (72 + 12 + 12 + 4, v/v) with detection at 254 nm. The calibration curve is linear. Recoveries of "spikes" averaged 101% with a standard deviation of 2%. Precision was better than 1.5%.