A Q- and X-band pulsed electron nuclear double resonance study of the structure and location of the vanadyl ions in the Cs salt of heteropolyacid PVMo11O40.

The location and coordination geometry of vanadium(IV) ions in the cesium salt of molybdovanadophosphoric heteropolyacid Cs(4)PVMo(11)O(40) were studied using orientation-selective pulsed ENDOR (electron nuclear double resonance) experiments. To enhance the orientation selectivity for the paramagnetic vanadyl species, these investigations were done at Q-band frequencies. It was possible to resolve interactions of the paramagnetic vanadyl ions (VO(2+)) with all relevant nuclei, (1)H, (31)P, (51)V, and (133)Cs.

The effects of hyaluronan and its fragments on lipid models exposed to UV irradiation.

The effects of hyaluronan and its degradation products on irradiation-induced lipid peroxidation were investigated. Liposomal skin lipid models with increasing complexity were used. Hyaluronan and its fragments were able to reduce the amount of lipid peroxidation secondary products quantified by the thiobarbituric acid (TBA) assay.

Role of ascorbic acid in stratum corneum lipid models exposed to UV irradiation.

Purpose: The effects of ascorbic acid on Stratum corneum lipid models following ultraviolet irradiation were studied adding iron ions as transition metal catalysts.

Methods: Lipid peroxidation was quantified by the thiobarbituric acid assay. The qualitative changes were studied on a molecular level by mass spectrometry.