On the retrograde condensation of one or two liquids

This contribution discusses the phenomena of retrograde condensation of one or two liquids. It w1 be shown that both phenomena can be well understood. Also the relation of retrograde condensation of one liquid phase with the condensation behavior of natural gas will be discussed. Similarly that of two liquid phases with multiple phase behavior occurring in low temperature reservoir fluids will be pointed out.     

Fluid multiphase equilibria and critical phenomena in binary and ternary mixtures of carbon dioxide, certain n-alkanols and tetradecane

Experimental results of fluid multiphase equilibria occurring in ternary mixtures of near-critical carbon dioxide, certain n-alkanols and tetradecane are presented. The following n-alkanols were used in this investigation: decanol, octanol, heptanol, hexanol and pentanol. In the ternary systems with decanol, octanol or heptanol a closed loop liquid-vapor two-phase region in the three-phase surface liquid-liquid-vapor was found. As far as the ternary system with decanol is concerned, this phenomenon is in agreement with an earlier and unexpected finding of Patton et al. (1993). In addition, it was also found in this study that the phase diagrams of the ternary mixtures with hexanol or pentanol as the n-alkanol show further complications.     

Identification of archaeal proteins that affect the exosome function in vitro

Background  

The archaeal exosome is formed by a hexameric RNase PH ring and three RNA binding subunits and has been shown to bind and degrade RNA in vitro. Despite extensive studies on the eukaryotic exosome and on the proteins interacting with this complex, little information is yet available on the identification and function of archaeal exosome regulatory factors.     

Comparison of the V-H and V-D phase diagrams by means of NMR

The phase diagrams of vanadium-hydrogen (V-H) and vanadium-deuterium (V-D) have been investigated by measuring the nuclear magnetic resonance (NMR) spectra of vanadium and deuterium in strongly textured vanadium foils. In the cubic α- and α′-phases both the V and D lines are unsplit. From the orientation dependence of the quadrupole splitting of the two resonances in the tetragonal β-phase it is found that for both atoms the electric field gradient is axially symmetric with its largest component parallel to the c-axis. In contrast to V-H, the β-phase of V-D exists only in a small region near D/V ratios of about 0·4 at 300°K; for higher D concentrations the α′-phase remains stable down to about 200°K, below which the orthorhombic δ-phase is formed. In spite of the nearly cubic arrangement of the V atoms in the δ-phase, the intensity of the vanadium line is reduced corresponding to first-order quadrupole splitting. From the absence of any V satellites in the δ-phase, it follows that the orientation of the principal axes of the field gradient at the V sites deviate strongly from the cube edges of the V lattice. For deuterium the largest component is parallel to one cube edge, which must be the c-axis of the orthorhombic cell. Thus the field gradient at the D sites has the same symmetry in the β- and δ-phase, with quadrupole frequencies of 100 and 55 kHz, respectively. This difference can be attributed to the fact that in the two phases different sites are occupied: octahedral sites in the β-phase and tetrahedral sites in the δ-phase.     

Modulation of humoral immune response to oral BCG vaccination by Mycobacterium bovis BCG Moreau Rio de Janeiro (RDJ) in healthy adults

We hypothesize that the energy strategy of a cell is a key factor for determining how, or if, the immune system interacts with that cell. Cells have a limited number of metabolic states, in part, depending on the type of fuels the cell consumes. Cellular fuels include glucose (carbohydrates), lipids (fats), and proteins. We propose that the cell's ability to switch to, and efficiently use, fat for fuel confers immune privilege. Additionally, because uncoupling proteins are involved in the fat burning process and reportedly in protection from free radicals, we hypothesize that uncoupling proteins play an important role in immune privilege. Thus, changes in metabolism (caused by oxidative stresses, fuel availability, age, hormones, radiation, or drugs) will dictate and initiate changes in immune recognition and in the nature of the immune response. This has profound implications for controlling the symptoms of autoimmune diseases, for preventing graft rejection, and for targeting tumor cells for destruction.     

Phase behaviour of globular protein and flexible polymer in an aqueous medium

A simple model for the phase behaviour of a globular protein and a flexible polymer in an aqueous medium is described, in which both the compact feature of the protein and the flexble feature of the polymer have been included. The phase diagrams calculated by using the model suggest that for a given protein, the behaviour depends strongly on the polymer molecular weight. Fluid-fluid-solid three-phase and fluid-fluid two-phase equilibria can be found only when the polymer molecular weight is sufficiently high; otherwise, the only two-phase region in the phase diagram is a fluid-solid two-phase region.     

Quadrupole coupling in EuO due to lattice imperfections

From ¹⁵³Eu nuclear spin-spin relaxation measurements it is concluded that quadrupole effects observed in ferromagnetic EuO are due to lattice imperfections.     

The influence of the stoichiometry on the Eu nuclear spin-spin relaxation in EuO single crystals

The ¹⁵³Eu spin-spin relaxation for two spherical EuO single crystals of different composition has been measured for two saturating field values of 2 and 6 T. The relaxation can be described by two time constants, a short one increasing with the magnetic field, arising from the Suhl-Nakamura coupling and a long one, due to the dipolar coupling, which is field independent. It is shown that the number of nuclei which are relaxed due to the dipolar coupling increases at increasing magnetic fields, in agreement with the Suhl-Nakamura theory. For the sample which is nearly stoichiometric the relative number of nuclei which is relaxed due to the SN coupling is much larger than for the sample which contains an excess of Eu atoms.