The relation between methods of coping during adulthood with a history of childhood sexual abuse and current psychological adjustment.

With a community sample of 192 women who had been sexually abused during childhood, the investigators determined if methods of coping in adulthood with the aftermath of child sexual abuse were associated with current symptoms of psychological distress. Multiple regression analyses indicated that disengagement methods of coping with the sexual abuse accounted for unique variance in general psychological distress even after controlling for characteristics of the abuse and methods of coping with other stressors. Disengagement methods of coping were also used more often to deal with the stressful aspects of having been sexually abused than to deal with other stressful events. In contrast, engagement methods of coping were used more often to deal with the other stressors than with sexual abuse. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of EPM long chain branching on TPO properties

In this paper the effects of EPM long chain branching are examined in terms of reheological, processing, and physical property responses in mechanically blended TPOs. Morphological effects induced by this polymer variable as indicated by SEM are detailed as well. The EPMs used in this study were produced by DSM Copolymer, Inc., in Baton Rouge, Louisiana.     

Transformation of fatty acid hydroperoxides by alkali and characterization of products

It has previously been determined that (13S,9Z,11E)-13-hydroperoxy-9,11-octadecadienoic acid was mainly converted into (13S,9Z,11E)-13-hydroxy-9,11-octadecadienoic acid by 5 N KHO with preservation of the stereochemistry of the reactant [Simpson, T.D., and Gardner, H.W. (1993)Lipids 28, 325–330]. In addition, about 20–25% of the reactant was converted into several unknown by-products. In the present work it was confirmed that the stereochemistry was conserved during the hydroperoxy-diene to hydroxydiene transformation, but also, novel by-products were identified. It was found that after only 40 min reaction (9Z)-13-oxo-trans-11,12-epoxy-9-octadecenoic acid accumulated to as much as 7% of the total. Later, (9Z)-13-oxo-trans-11,12-epoxy-9-octadecenoic acid began to disappear, and several other compounds continued to increase in yield. Two of these compounds, 2-butyl-3,5-tetradecadienedioic acid and 2-butyl-4-hydroxy-5-tetradecenedioic acid, were shown to originate from (9Z)-13-oxo-trans-11,12-epoxy-9-octadecenoic acid, and they accumulated up to 2–3% each after 4 to 6 h. Some other lesser products included 11-hydroxy-9,12-heptadecadienoic acid, 3-hydroxy-4-tridecenedioic acid, 13-oxo-9,11-octadecadienoic acid and 12,13-epoxy-11-hydroxy-9-octadecenoic acid. Except for the latter two, most or all of the compounds could have originated from Favorskii rearrangement of the early product, (9Z)-13-oxo-trans-11,12-epoxy-9-octadecenoic acid, through a cyclopropanone intermediate.     

Cyclic Lean Reduction of NO by CO in Excess H2O on Pt–Rh/Ba/Al2O3: Elucidating Mechanistic Features and Catalyst Performance

This study provides insight into the mechanistic and performance features of the cyclic reduction of NO_x by CO in the presence and absence of excess water on a Pt–Rh/Ba/Al₂O₃ NO_x storage and reduction catalyst. At low temperatures (150–200 °C), CO is ineffective in reducing NO_x due to self-inhibition while at temperatures exceeding 200 °C, CO effectively reduces NO_x to main product N₂ (selectivity >70 %) and byproduct N₂O. The addition of H₂O at these temperatures has a significant promoting effect on NO_x conversion while leading to a slight drop in the CO conversion, indicating a more efficient and selective lean reduction process. The appearance of NH₃ as a product is attributed either to isocyanate (NCO) hydrolysis and/or reduction of NO_x by H₂ formed by the water gas shift chemistry. After the switch from the rich to lean phase, second maxima are observed in the N₂O and CO₂ concentrations versus time, in addition to the maxima observed during the rich phase. These and other product evolution trends provide evidence for the involvement of NCOs as important intermediates, formed during the CO reduction of NO on the precious metal components, followed by their spillover to the storage component. The reversible storage of the NCOs on the Al₂O₃ and BaO and their reactivity appears to be an important pathway during cyclic operation on Pt–Rh/Ba/Al₂O₃ catalyst. In the absence of water the NCOs are not completely reacted away during the rich phase, which leads to their reaction with NO and O₂ upon switching to the subsequent lean phase, as evidenced by the evolution of N₂, N₂O and CO₂. In contrast, negligible product evolution is observed during the lean phase in the presence of water. This is consistent with a rapid hydrolysis of NCOs to NH₃, which results in a deeper regeneration of the catalyst due in part to the reaction of the NH₃ with stored NO_x. The data reveal more efficient utilization of CO for reducing NO_x in the presence of water which further underscores the NCO mechanism. Phenomenological pathways based on the data are proposed that describes the cyclic reduction of NO_x by CO under dry and wet conditions.     

Prediction of the structures of proteins with the UNRES force field, including dynamic formation and breaking of disulfide bonds

The presence of disulfide bonds is essential for maintaining the structure and function of many proteins. The disulfide bonds are usually formed dynamically during folding. This process is not accounted for in present algorithms for protein-structure prediction, which either deduce the possible positions of disulfide bonds only after the structure is formed or assume fixed disulfide bonds during the course of simulated folding. In this work, the conformational space annealing (CSA) method and the UNRES united-residue force field were extended to treat dynamic formation of disulfide bonds. A harmonic potential is imposed on the distance between disulfide-bonded cysteine side-chain centroids to describe the energetics of bond distortion and an energy gain of 5.5 kcal/mol is added for disulfide-bond formation. Formation, breaking and rearrangement of disulfide bonds are included in the CSA search by introducing appropriate operations; the search can also be carried out with a fixed disulfide-bond arrangement. The algorithm was applied to four proteins: 1EI0 (alpha), 1NKL (alpha), 1L1I (beta-helix) and 1ED0 (alpha + beta). For 1EI0, a low-energy structure with correct fold was obtained both in the runs without and with disulfide bonds; however, it was obtained as the lowest in energy only with the native disulfide-bond arrangement. For the other proteins studied, structures with the correct fold were obtained as the lowest (1NKL and 1L1I) or low-energy structures (1ED0) only in runs with disulfide bonds, although the final disulfide-bond arrangement was non-native. The results demonstrate that, by including the possibility of formation of disulfide bonds, the predictive power of the UNRES force field is enhanced, even though the disulfide-bond potential introduced here rarely produces disulfide bonds in native positions. To the best of our knowledge, this is the first algorithm for energy-based prediction of the structure of disulfide-bonded proteins without any assumption as to the positions of native disulfides or human intervention. Directions for improving the potentials and the search method are suggested.     

Improved conformational space annealing method to treat β-structure with the UNRES force-field and to enhance scalability of parallel implementation

Successful application of physics-based protein-structure prediction methods depends on sophisticated computational approaches to global optimization of the conformational energy of a polypeptide chain. One of the most effective procedures for the global optimization of protein structures appears to be the Conformational Space Annealing (CSA) method. CSA is a hybrid method which combines genetic algorithms, essential aspects of the build-up method and a local gradient-based minimization. CSA evolves the population of conformations through genetic operators (mutations, i.e. perturbations of selected geometric parameters, and crossovers, i.e. exchange of selected subsets of geometric parameters between conformations) to a final population optimizing their conformational energy. Implementation of the CSA method with the united-residue force field (UNRES, in which each amino-acid residue is represented by two interaction sites, namely the united peptide group and the united side-chain) was enhanced by introducing new crossover operations consisting of (i) copying β-hairpins, (ii) copying remote strand pairs forming non-local β-sheets, and (iii) copying α-helical segments. A mutation operation, which shifts the position of a β-turn, was also introduced. The new operations promote β-structure, and are essential for searching the conformational space of proteins containing both α- and β-structure; without these operations, excessive preference of α-helical structures is obtained, even though these structures are high in energy. Parallelization of the CSA method has also been enhanced by removing most of the synchronization steps; the improved algorithm scales almost linearly up to 1,000 processors with over 75% average performance.     

High Dose trans-10,cis-12 CLA Increases Lean Body Mass in Hamsters, but Elevates Levels of Plasma Lipids and Liver Enzyme Biomarkers

The current study examined the efficacy of graded doses of c9,t11 and t10,c12 CLA isomers on body composition, energy expenditure, hepatic and serum lipid liver biomarkers in hamsters. Animals (n = 105) were randomized to seven treatments (control, 1, 2, 3% of c9,t11; 1, 2, 3% of t10,c12) for 28 days. After 28 days treatment, 1–3% of t10,c12 lowered (p < 0.05) body fat mass compared to the control group. The 1–3% t10,c12 and 3% c9,t11 fed groups showed higher (p < 0.05) lean mass compared to other groups. We observed unfavorable changes in plasma total cholesterol and non-HDL cholesterol levels in animals fed with 3% t10,c12 CLA isomers. The 2%, 3% t10,c12 groups presented elevated (p < 0.05) ALT levels. The present data suggest that a diet enriched with more than 2% t10, c12 led to liver malfunction and poses unfavorable changes on plasma lipid profiles. The 1% t10,c12 CLA lowered (p < 0.05) body fat mass and increased (p < 0.05) lean body mass. The c9,t11 CLA has less potent actions than t10,c12 CLA. We conclude that the actions of CLA on energy and lipid metabolism are form and dose dependent in the hamster model.     

The Brain Oxylipin Profile Is Resistant to Modulation by Dietary n-6 and n-3 Polyunsaturated Fatty Acids in Male and Female Rats

Oxylipins are bioactive lipids formed by the monooxygenation of polyunsaturated fatty acids (PUFA). Eicosanoids derived from arachidonic acid (ARA) are the most well-studied class of oxylipins that influence brain functions in normal health and in disease. However, comprehensive profiling of brain oxylipins from other PUFA with differing functions, and the examination of the effects of dietary PUFA and sex differences in oxylipins are warranted. Therefore, female and male Sprague–Dawley rats were provided standard rodent diets that provided additional levels of the individual n-3 PUFA α-linolenic acid (ALA), eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA), or the n-6 PUFA linoleic acid (LNA) alone or with ALA (LNA + ALA) compared to essential fatty acid-sufficient control diets. Oxylipins and PUFA were quantified in whole brains using HPLC-MS/MS and GC, respectively. Eighty-seven oxylipins were present at quantifiable levels: 51% and 17% of these were derived from ARA and DHA, respectively. At the mass level, ARA and DHA oxylipins comprised 81–90% and 6–12% of total oxylipins, while phospholipid ARA and DHA represented 25–35% and 49–62% of PUFA mass, respectively. Increasing dietary n-3 PUFA resulted in higher levels of oxylipins derived from their precursor PUFA; otherwise, the brain oxylipin profile was largely resistant to modulation by diet. Approximately 25% of oxylipins were higher in males, and this was largely unaffected by diet, further revealing a tight regulation of brain oxylipin levels. These fundamental data on brain oxylipin composition, diet effects, and sex differences will help guide future studies examining the functions of oxylipins in the brain.