Effect of Gadolinium(III) Ions on the Phase Behaviour of Dimyristoylphosphatidyl Serine Multilamellar Liposomes

The effects of low concentrations of Gd³⁺ on dimyristoylphosphatidyl serine (DMPS) multilamellar liposomes were studied by differential scanning calorimetry (DSC). At low ionic strength merely a shifting upscale and a broadening of the main transition peak were observed. At high ionic strength, Gd³⁺ provoked the formation of a few clearly-discernible high-temperature components. Increase of the Gd level affected the relative intensities of these components, whereas the corresponding midpoints and half-widths remained unchanged. At the same time, in the presence of about 20 mol% dimyristoylphosphatidyl choline in the mixture with DMPS, similar secondary peaks appeared, but their positions were markedly shifted, to extents dependent on the Gd concentration. Interpretation of the data in terms of two-dimensional crystal structures is suggested. This revised version was published online in July 2006 with corrections to the Cover Date.     

An intermediate radial distribution curve maximum of water and its relation to the topology of the network of H-bonds in liquid water

The structure of a complex of a water molecule with first and second coordination sphere molecules was analyzed. Model structures were calculated using the TIP3P and Poltev-Malenkov potentials. It was found that stable structures of four water molecules could exist. In these structures, oxygen atoms are situated at characteristic distances of 0.37 nm from each other. This distance corresponds to the “intermediate” maximum of the radial distribution curve. The existence of such structures correlates with the formation of bifurcated bonds in liquid water. This result can be obtained by changing the topology of the water structure while retaining the tetrahedral character of structural elements.     

Dielectric Characteristics of Highly Diluted Aqueous Diclofenac Solutions in the Frequency Range of 20 Hz to 10 MHz

Physics of Wave Phenomena - It is found that electrical conduction of highly diluted aqueous diclofenac solutions nonmonotonically depends on their concentration under serial centesimal dilutions...