Solid UO dissolution and uranium speciation in aqueous solutions that promote formation of uranyl peroxide macroanions was examined, with a focus on the role of alkali metals. UO powders were dissolved in solutions containing XOH (X = Li, Na, K) and 30% HO. Inductively coupled plasma optical emission spectrometry (ICP-OES) measurements of solutions revealed linear trends of uranium versus alkali concentration in solutions resulting from oxidative dissolution of UO, with X:U molar ratios of 1.0, showing that alkali availability determines the U concentrations in solution. The maximum U concentration in solution was 4.20 × 10 parts per million (ppm), which is comparable to concentrations attained by dissolving UO in boiling nitric acid, and was achieved by lithium hydroxide promoted dissolution. Raman spectroscopy and electrospray ionization mass spectrometry (ESI-MS) of solutions indicate that dissolution is accompanied by the formation of various uranyl peroxide cluster species, the identity of which is alkali concentration dependent, revealing remarkably complex speciation at high concentrations of base.

Vitamin D3 has been called the “sunshine” vitamin since the formation of vitamin D is mediated by exposure to sunlight. Vitamin D3 is linked to many health benefits, however serum levels of vitamin D3 have been decreasing over the last few decades and the lower levels of vitamin D3 may have consequences on normal physiology. We investigated the association between serum 25-hydroxyvitamin D (25(OH)D) levels and stratum corneum conductance as well as the effect of topical application of cholecalciferol (vitamin D3) on dry skin. Eighty three subjects were recruited and blood serum levels and skin conductance measurements were taken after a one week washout. A correlation was observed between vitamin D levels and skin moisture content, individuals with lower levels of vitamin D had lower average skin moisture. Subsequently, a 3-week split leg, randomized, vehicle controlled clinical study was conducted on a subset of 61 of the above individuals who were identified with non-sufficient vitamin D serum levels. Topical supplementation with cholecalciferol significantly increased measurements of skin moisturization and resulted in improvements in subjective clinical grading of dry skin. Taken together our finding suggest a relationship between serum vitamin D3 (25(OH)D) levels and hydration of the stratum corneum and further demonstrate the skin moisture benefit from topical application of vitamin D3.

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