Severity of delayed (“secondary”) cerebral energy failure after acute hypoxia-ischemia is related to the time integral of acute ATP depletion

The aim of this study was to reproduce the delayed (secondary) cerebral energy failure previously described in birth-asphyxiated newborn infants and to investigate relationships between primary insult severity and the extent of the delayed energy failure. Phosphorus (³¹P) magnetic resonance spectroscopy (MRS) at 7 T was used to study the brains of 12 newborn piglets during an acute, reversible, cerebral hypoxic-ischemic episode which continued until nucleotide triphosphates (NTP) were depleted. After reperfusion and reoxygenation, spectroscopy was continued for 48 h. High-energy metabolite concentrations returned to near normal levels after the insult, but later they fell as delayed energy failure developed. The time integral of NTP depletion in the primary insult correlated strongly with the minimum [phosphocreatine (PCr)]/[inorganic orthophosphate (P_i)] observed 24–48 h after the insult. (Linear regression analysis gave slope –8.04 h^–1; ordinate intercept=1.23;r=0.92;P<0.0001.) This model is currently being used to investigate the therapeutic potential of various cerebroprotective strategies including hypothermia.     

Basic dyeability and acid content of high-conversion polyacrylonitrile

Previous data have shown that the basic dyeability of acrylic polymers increases at a given specific viscosity as the peroxydisulfate-to-bisulfite ratio, that is, the catalyst-toactivator (C/A) ratio, is increased. This study represents an effort to understand better the role of the initiator system on the basic dyeability, the acid group composition, and the chain composition of acrylic polymers by preparing model polymers with radioactive initiators. As the C/A ratio is increased, the molecular weight distribution broadens as measured by the M?_v/M?_n ratio, the latter obtained by osmometry. There is also a significant effect of both C/A ratio and molecular weight on the sulfate group content per molecule, but there is no effect of C/A ratio on the number of basic dye sites per molecule, the number of sulfonate groups per molecule, or the weak acid groups per molecule. These effects can be explained by invoking a chain transfer to activator reaction in addition to the usual method of chain termination by recombination. The basic dyeability is found to correlate with the number-average molecular weight and with the number of strong acid groups plus the nonchromophoric weak acid groups.     

The adaptive aspects of the Golden Fantasy.

Reviews S. Smith's (1977) contribution regarding the "golden fantasy" phenomenon of many infantile and narcissistic patients, which is viewed as a manifestation of deficits associated with self-definition and interpersonal relatedness. Reasons are suggested as to why such fantasies are often difficult to coax to consciousness and are unyielding to subsequent interpretive efforts. The adaptive, life-sustaining aspects of such golden fantasies, via their ego-integrative and self-defining properties, are highlighted. Clinical vignettes illustrate the dangers in establishing real object ties. Subsequent treatment implications regarding the importance of dealing with golden fantasies as bridges to treatment alliance formation are elaborated. The importance is emphasized of the holding environment in treatment, the shift to developmentally more mature forms of the therapeutic alliance, and countertransference dilemmas. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Physicochemical and toxicological properties of commercial carbon blacks modified by reaction with ozone

Ozonation of two commercial carbon blacks (CBs), Printex 90 (P90) and Flammruss 101 (F101), was carried out and changes in their morphology, physical properties, and cytotoxicity were examined. The hypothesis examined was that different methods of manufacture of CBs influence their chemical reactivity and toxicological properties. Structural changes were examined by X-ray photoelectron spectroscopy, infrared spectroscopy, Raman spectroscopy, and electron paramagnetic resonance spectroscopy (EPR). Introduction of surface oxygen functionality upon ozonation led to changes in surface charge, aggregation characteristics, and free radical content of the CBs. However, these changes in surface functionality did not alter the cytotoxicity and release of inflammation markers upon exposure of the CBs to murine macrophages. Interaction of macrophages with F101 resulted in higher levels of inflammatory markers than P90, and the only structural correlation was with the higher persistent radical concentration on the F101.     

A high-power CH3F laser for plasma diagnostics

A high-power, optically pumped, methyl fluoride laser operating at 496 μm has been developed for plasma diagnostic applications. An output power of 100 mW has been measured directly on a calorimeter. The high-pump power utilized in this experiment has also allowed the first observation of saturation in far-infrared output power resulting from severe vibrational bottlenecking. The effect of buffer gases in relieving this bottlenecking is described and compared to a simple rate-equation model     

Carbon mesophase-substrate interactions

The formation, growth and coalescence of mesophase materials have been followed by hot stage microscopy and by room temperature examination of polished surfaces for various mesophase-forming materials and in the presence of various substrates. The appearance of mesophase particles should be preceded by polymerization of isotropic material into sheet-like molecules, followed by orientation of the sheet-like molecules into ordered regions. Precipitation, growth and coalescence should require ordering of small molecules in a viscous medium. Our results indicate that dynamic motion in the fluid, rather than the presence of nucleating particles, is the controlling factor, very likely reflecting a small mesophase-isotropic liquid interfacial energy. Where dynamic motion is restricted, as in the interstices of a yarn, mesophase formation and growth are also restricted. Alignment of mesophase material with a substrate is primarily controlled by the motion of the mesophase droplets as they flow across the substrate. In general, substrates are not wetted by mesophase in the presence of isotropic material. Certain surfaces are wetted by the mesophase droplets but alignment appears to be controlled more by flow orientation than by surface energy interaction.