Residue ionization states were calculated in nine crystal structures of bacteriorhodopsin trapped in bR, early M, and late M states by multiconformation continuum electrostatics. This combines continuum electrostatics and molecular mechanics, deriving equilibrium distributions of ionization states and polar residue and water positions. The three central cluster groups [retinal Schiff base (SB),...

The energetics, geometrical and electronic structure, ionization processes, dynamics, and dissociation pathways of neutral and singly and doubly ionized water dimers are investigated with simulations employing the BomOppenheimer local-spin-density functional molecular dynamies (BO-LSD-MD) method. Vertical and adiabatic ionization potentials and dissociation energies and barriers are calculated ...

Energetics and geometrical structures of neutral, (H2O)n, and ionized, (H2O)n, water clusters, with n ) 2-5, are investigated using local-spin-density functional electronic structure calculations with exchange-correlation gradient corrections. While the ground-state structures of the neutral clusters are hydrogen-bonded cyclic ones, those of the molecular ions are noncyclic. The lowest energy i...

In laboratory sandpack tests for heavy oil recovery by alkaline flooding, it was found that wettability alteration of the sand had a significant impact on oil recovery. In this work, a heavy oil of 14 API was used to examine the effect of organic acids in the oil and water chemistry on wettability alteration. From interfacial tension measurements and sand surface composition analysis, it was c...

The effects of various additives on the physical properties of an amorphous sugar matrix were compared. Amorphous, sugar-additive mixtures were prepared by freeze-drying and then rehumidified at given RHs. Sucrose and eighteen types of substances were used as the sugar and the additive, respectively, and water sorption, glass-to-rubber transition, and protein stabilization during freeze-drying ...

magnesium hydroxide mg(oh)2 nanorods with diameters of 90±10nm and lengths of more than 2μms were prepared by a simple route at ~75oc in ambient air. the approach is based on reaction of magnesium powder and de-ionized water without the use of any harmful, toxic or corrosive reagents. characterization using x-ray diffraction (xrd) shows single crystalline structure of mg(oh)2 (brucite) whereas ...

Of the three magnesium fractions in plasma, free ionized magnesium (Mg2+) has the greatest biological activity. Accordingly, information concerning this form in plasma is of cardinal importance to investigations in biometry and human pathology. For this reason, we developed an indirect assay for ionized magnesium in which Mg2+ is determined as the difference between ultrafiltrable magnesium, as...

The optical and electrical characteristics of a graphene oxide solution (GS) with different graphene oxide (GO) concentrations in de-ionized water are investigated via the electrochemical impedance spectroscopy (EIS) method. The measurement results produced by the EIS for the GS are represented with both Bode and Nyquist plots in a frequency range from 1 kHz to 10 MHz. Using these results, we d...

During pregnancy, maternal calcium needs increase as a result of increasing calcium requirements for fetal bone development. These needs have to be completely supplied by the mother via placental transfer. Several studies link low serum ionized calcium concentrations with the development of hypertension and pregnancy-induced hypertension. We hypothesized that maternal hypocalcemia would develop...