Phase transformations in bulk nanostructured potassium niobiosilicate glasses.

In potassium niobiosilicate (KNS) glasses, nanostructuring can be driven and controlled by thermal treatments at the glass transition temperature and/or by modulation of the chemical composition. The tight relationship between nanostructure and nonlinear optical properties suggests these bulk nanomaterials as an appealing route to nanophotonics. The focus of this paper is placed on assessing the phase transformations which occur in these materials upon annealing at the glass transition temperature and subsequent heating. High-temperature resolved X-ray diffraction (HTXRD) and high-resolution transmission electron microscopy (HRTEM) experiments are integrated with previously published results for in-depth insight. It will be shown that nanostructuring evolves from nucleation of niobium-rich nanocrystals, which are up to 20 nm large, uniformly distributed in the matrix bulk, and metastable. Formation kinetics as well as phase transformation of the nanocrystals are determined by the glass composition. Depending on it, nanocrystal nucleation can be preceded or not by phase separation, and the nanocrystals' phase transition can be of first or second order.

A comparative study of the permeation of dihexadecyl phosphate vesicles by various carboxylic acids and some of their tetrazole analogues.

The evaluation of the effect that perturbers may have on a membrane model is described. The model was made from dihexadecyl phosphate bilayers. The perturbers used were carboxylic acids and some of their tetrazole analogues. The results show a good correlation between the permeation properties of the carboxylic acids and tetrazole analogues. Moreover, this study reveals that membrane-perturbing effects are mainly under the control of conformational parameters and dependent on the carbon chain length of the permeants.

Inhibition of glyoxalase I by various clinically used anticancer drugs.

The antiglyoxalase activity of eight well-known anticancer drugs has been evaluated, their I50 values were determinated and compared to those of standard inhibitors S-octylglutathione and squaric acid. Among them methotrexate was found to be as potent as S-octylglutathione.