The structural properties resulting from the reciprocal influence between water and three well-known homologous disaccharides, namely, trehalose, maltose, and sucrose, in aqueous solutions have been investigated in the 4-66 wt % concentration range by means of molecular dynamics computer simulations. Hydration numbers clearly show that trehalose binds to a larger number of water molecules than ...

Understanding adaptation to extreme environments remains a challenge of high biotechnological potential for fundamental molecular biology. The cytosol of many microorganisms, isolated from saline environments, reversibly accumulates molar concentrations of the osmolyte ectoine to counterbalance fluctuating external salt concentrations. Although they have been studied extensively by thermodynami...

infection is the primary source of mortality in burn patients. one of the main treatment methods of burn wound infections is topical antimicrobial therapy, in which drugs have to permeate a dead tissue called eschar. unfortunately, most antimicrobial agents can not permeate eschar in therapeutic levels. surprisingly, permeation properties of this barrier and effects of chemical or environmental...

A stable, hydrogen-defect structure of post-perovskite (hy-ppv, Mg1 xSiH2xO3) has been determined by first-principles calculations of the vibrational and elastic properties up to 150 GPa. Among three potential hy-ppv structures analyzed, one was found to be stable at pressures relevant to the lower-mantle D 00 region. Hydrogen has a pronounced effect on the elastic properties of post-perovskite...

A combination of simulations and Fourier transform infrared spectroscopy was used to examine the effect of three ionic solutes ~KCl, NaCl, and KSCN!, the polar solute urea, and the osmolyte trimethylamine-N-oxide ~TMAO! on a water structure. The ionic solutes increase the mean water– water H-bond angle in their first hydration shell concomitantly shifting the OH stretching mode to higher freque...

Different inorganic and organometallic gold(III) and gold(I) complexes have been tested in the addition of water and methanol to terminal alkynes. Anionic and neutral organometallic gold(III) compounds can efficiently mediate these reactions in neutral media in refluxing methanol. The compounds are added in catalytic amounts (1.6-4.5 mol % with respect to the alkyne). Thus, compounds of the gen...

The dimensions of multibilayer stacks of lipids with terminal diene groups were studied before and after polymerization at variable hydration by means of X-ray diffraction, gravimetry, and infrared spectroscopy. The short-range hydration force acting between the bilayers of lipids with phosphatidylcholine and -ethanolamine headgroups is not affected by lipid polymerization. Consequently, contri...

We have studied the effect of humidity on the electronic properties of DNA base pairs. We found that the hydrogen links of the nucleobases with water molecules lead to a shift of the pi electron density from carbon atoms to nitrogen atoms and can change the symmetry of the wave function for some nucleobases. As a result, the orbital energies are shifted which leads to a decrease in the potentia...

Two experiments were conducted to evaluate the relationships between nutrients degradability, kinetics of hydration, functional specific gravity (FSG) of the three types of beet pulp (BP) including fine (FBP), normal (NBP) and pelleted (PBP) BP. In experiment 1, about 3 g of samples was weighed in sealed nylon bags (6 cm×7.5 cm, 40±5 µm pore size), incubated in rumen of two cannulated Holstein ...

physiologists have shown that increased fluids improve skeletal muscle performance in prolonged exercise.typical orders provide for 125 ml of intravenous fluids per hour in patients taking limited oral fluids during labor. our purpose in this study was to determine whether increased intravenous fluids affect the progress of labor. in a prospective randomized institutional clinical trial, one-hu...