Hydrogen-Bond Rearrangement and Intermolecular Proton Transfer in Protonated Methanol Clusters

Vibrational predissociation spectra (VPS) of hydrogen-bonded and non-hydrogen-bonded (free) OH stretches within the frequency range of 2700–3800 cm⁻¹ are closely analyzed to determine the isomeric structures and proton location in protonated methanol clusters, H⁺(CH₃OH)_n. The present report emphasizes protonated methanol tetramers and pentamers, which are predicted by ab initio calculations to exist in linear and cyclic forms. Only one isomer with linear structure was identified in the VPS of protonated methanol tetramers in a supersonic expansion. Both linear and cyclic configurations were found for protonated methanol pentamers, and an isomeric transition between these two structures due to hydrogen-bond rearrangement was observed at a cluster temperature of 190 K. Ab initio calculations indicated that the excess proton in these clusters can be either localized on one methanol unit, as in cyclic H⁺(CH₃OH)₄ and linear H⁺(CH₃OH)₅ isomers, or delocalized between two methanol molecules, as in linear H⁺(CH₃OH)₄ and cyclic H⁺(CH₃OH)₅ isomers. Such unique proton delocalization behavior is revealed in the VPS of cyclic H⁺(CH₃OH)₅, which is recognized as a symmetric five-membered pentamer by its characteristic free-OH stretching absorption at 3647 cm⁻¹ and hydrogen-bonded OH stretches at 3448 and 3461 cm⁻¹. Using protonated methanol pentamers as a model system, a proton transfer mechanism is suggested to involve intracluster proton transfer mediated by a sequence of hydrogen-bond breaking and reforming processes. This appealing mechanism can be closely associated with the exceptionally high proton mobility in liquid methanol.     

A comparison of posttraumatic stress disorder in veterans with and without spinal cord injury.

The authors assessed effects of paraplegic and quadriplegic spinal cord injuries (SCls) on posttraumatic stress disorder (PTSD) by comparing severity and prevalence of PTSD in these groups to a sample of controls who experienced traumatic injuries other than SCI. The authors found that veterans with quadriplegia reported significantly less severe current PTSD symptoms than controls who were not significantly different from veterans with paraplegia. These results suggest that sustaining a quadriplegic SCI decreases risk of current PTSD, whereas sustaining a paraplegic SCI is associated with greater risk of PTSD, although the risk is no greater than that incurred from experiencing the trauma itself. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

EFFECTS OF H2S ADDITION ON THE PERFORMANCE OF FRESH VS. USED CoMo CATALYSTS

When a Co/Mo catalyst is used for processing vanadium-containing heavy oils, vanadium deposits on the catalyst. As the amount of vanadium on the CoMo catalyst increases, the catalytic effects of CoMo decline and the presence of vanadium starts to influence the hydroprocessing products. Model feeds have been used to explore the changes in the catalytic activity of CoMo, aged CoMo, and VS_x on alumina. Desulfurization, denitrogenation, deoxygenation, aromatics hydrogenation, and metals removal were monitored. Upon the addition of hydrogen sulfide to hydrogen, improvements in the catalysts for aromatics hydrogenation, denitrogenation and metals removal were observed.     

Sex differences in psychotherapy with older people.

Examines sex-related differences in late-middle and old age that influence the initiation, process, and goals of psychotherapy with older patients. These differences include demographic characteristics, responses to health problems and physical changes, psychiatric symptoms and diagnoses, and strengths. Possible barriers to these therapeutic goals and implications of historical shifts in sex roles in society are discussed. (68 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A multimodal treatment model for a mental hospital: Designing specific treatments for specific problems.

Describes a program based on A. A. Lazarus's (see PA, Vol 57:6345) multimodal behavior therapy, which provides specific treatments identified across 7 major modalities: behavior, affect, sensory, imagery, cognition, interpersonal, and drugs (BASIC ID). The advantages of utilizing the multimodal concept in a hospital setting with a large pool of therapy resources are examined. A "treatment module" approach to accomplish multimodal therapy is introduced and discussed. The BASIC ID profile and the treatment module are presented as the structure for systematic treatment planning and evaluation. (13 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of different culture conditions on biological potential and metabolites production in three Penicillium isolates

The genus Penicillium is well known for its importance in drug and food production. Certain species are produced on an industrial scale for the production of antibiotics (e.g. penicillin) or for insertion in food (e.g. cheese). In the present work, three Penicillium species, part of the natural mycobiota growing on various food products were selected – P. ochrochloron, P. funiculosum and P. verrucosum var. cyclopium. The objective of our study was to value these species from the point of view of production of bioactive metabolites. The species were obtained after inoculation and growth in Czapek and Malt media. Both mycelia and culture media were analyzed to monitor the production of different metabolites by each fungus and their release to the culture medium. The concentrations of sugars, organic acids, phenolic acids and tocopherols were determined. Antioxidant activity of the phenolic extracts was evaluated, as also the antimicrobial activity of phenolic acids, organic acids and tocopherols extracts. Rhamnose, xylose, fructose and trehalose were found in all the mycelia and culture media; the prevailing organic acids were oxalic and fumaric acids, and protocatechuic and p-hydroxybenzoic acids were the most common phenolic acids; γ-tocopherol was the most abundant vitamin E isoform. Generally, the phenolic extracts corresponding to the mycelia samples revealed higher antioxidant activity. Concerning the antimicrobial activity there were some fluctuations, however all the studied species revealed activity against the tested strains. Therefore, the in-vitro bioprocesses can be an alternative for the production of bioactive metabolites that can be used by pharmaceutical industry.