Atomic force microscopy studies on whey proteins

β-Lactoglobulin, standard whey protein concentrate (WPC 80) and cold-gelling whey protein concentrate (mWPC 80) were dried onto mica sheets at 0.03-3 μg cm⁻² surface load and imaged with atomic force microscopy (AFM) in tapping mode. β-Lactoglobulin and WPC 80 spread to a fairly even 2.5 nm thick layer at about monolayer surface load, while mWPC showed particle sizes of 20-30 nm laterally. There is little difference in the observed structures between 0.3 and 3 μg cm⁻² apart from the higher surface load. At 0.03 μg cm⁻², β-lactoglobulin spread somewhat more thinly than WPC 80. With the addition of DTT, mWPC spread evenly with only few particles in evidence. AFM appears to be a convenient method for the characterization of aggregation states of sub-micrometer protein particles.     

Computerized smoking cessation program for the worksite: Treatment outcome and feasibility.

This study demonstrated the effectiveness of a computer-delivered smoking cessation program for the worksite. 58 VA Medical Center employees were randomly assigned to a computer group (computerized nicotine fading and stop-smoking contest) or a contest-only group. In comparison with the contest-only group, the computer group had nonsignificantly higher abstinence rates across follow-up, had marginally lower CO levels at the 3- and 6-month follow-ups, and smoked cigarettes with lower nicotine levels at the 10-day and 6-month follow-ups. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Smoking following myocardial infarction: A critical review of the literature.

Reviews studies on the effects of quitting smoking following acute myocardial infarction (MI). Topics discussed include definitions of abstinence used in the literature, reliance on patient self-reports, and personality and environment variables. Findings indicate that a significant number of MI patients quit smoking without receiving formal training and that those who quit suffer less subsequent mortality from coronary heart disease. It is argued that studies have overestimated cessation rates and underestimated negative effects of continued smoking due to their methodology. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Thermal Motion and Conformational Disorder in Protein Crystal Structures: Comparison of Multi-Conformer and Time-Averaging Models

Models describing thermal motion and conformational variability in protein crystal structures were applied to the refinement of a 1.8 Å crystal structure of penicillopepsin. Three methods were tested: conventional refinement using restrained B factors, multiple-conformer refinement, and time-averaging refinement using molecular dynamics. The information content of the models was assessed by cross-validation and by estimating the phase accuracy of the model using phases obtained by multiple isomorphous replacement. The R value always decreased when using multi-conformer and time-averaging methods, as compared to conventional refinement. In contrast, the cross-validated (“free”) R value and the phase accuracy worsened for time-averaging in vacuum. Inclusion of solvent produced a slight improvement of both measures compared to conventional refinement. Multi-conformer refinements always improved both measures. An optimum was reached for simultaneous refinement of between four and eight conformers. At the resolution limit of the penicillopepsin data, multi-conformer refinement is an efficient method to describe conformational variability and thermal motion.     

Why do people need self-esteem? Converging evidence that self-esteem serves an anxiety-buffering function.

Three studies were conducted to assess the proposition that self-esteem serves an anxiety-buffering function. In Study 1, it was hypothesized that raising self-esteem would reduce anxiety in response to vivid images of death. In support of this hypothesis, Ss who received positive personality feedback reported less anxiety in response to a video about death than did neutral feedback Ss. In Studies 2 and 3, it was hypothesized that increasing self-esteem would reduce anxiety among individuals anticipating painful shock. Consistent with this hypothesis, both success and positive personality feedback reduced Ss' physiological arousal in response to subsequent threat of shock. Thus, converging evidence of an anxiety-buffering function of self-esteem was obtained. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A controlled smoking cessation trial for substance-dependent inpatients.

Smoking treatment for newly recovering drug and alcohol-dependent smokers in a residential rehabilitation program was examined. The randomly assigned conditions (n?=?50 each) were multicomponent smoking treatment (MST), MST plus generalization training of smoking cessation to drug and alcohol cessation (MST+G), or usual care (UC). Fifty participants who declined smoking treatment (treatment refusers) also were studied. Both treatment conditions achieved continuous smoking abstinence rates (MST: 12%. MST+G: 10%, at 12-month follow-up) that were significantly higher than in the UC condition (0%). The MST condition had a continuous drug and alcohol abstinence rate that was significantly higher than that of the MST+G condition (40% vs. 20% at 12-month follow-up) although neither differed significantly from that of the UC condition (33%). These results support the feasibility of smoking treatment for this population and provide information regarding appropriate treatment components. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Milk – A new source for bioactive phospholipids for use in food formulations

The fat globules of milk are surrounded by a membrane, which contains a triple layer of phospholipids. Concentrated cream is thus a very good raw material for further processing in order to make a powder, enriched in phospholipids. A powder can in this way easily be produced with 20% phospholipids using only common dairy processes such as centrifugation and membrane filtration. Milk phospholipids differ in compositions from existing commercial sources such as soybean lecithins and egg lecithins particularly with respect to the content of two bioactive phospholipids namely sphingomyelin (about 24%) and phosphatidylserine (12%). Sphingomyelin is an active agent controlling the intestinal uptake of cholesterol and triacylglycerols in human nutrition. Intake of phosphatidyl serine has clinically documented effects in maintaining cognitive performance like memory and stress control. A milk phospholpids enriched product thus offers a 100% natural alternative to the well‐established, semi‐synthetic head‐group exchanged phosphatidyl serine from soy lecithin now existing on the market for functional foods formulations.     

Manganese speciation in dilute waters of the Precambrian shield, Canada

In contrast to its physical state in some geographical areas, manganese in waters draining the Precambrian shield in Canada is mostly non-particulate. Using a differential pulse anodic stripping voltammetry speciation technique, we demonstrate a trend from ionic Mn(II) dominance at low pH to an increasing proportion of colloidal manganese oxyhydroxides at pH 5.5 in non-dystrophic waters. The relationship of Mn(II) with pH in the oxic, non-dystrophic samples is consistent with a Hausmannite or Feitknechtite controlling phase.     

Direct and Transfer Hydrogenation of Ketones and Imines with a Ruthenium N‐Heterocyclic Carbene Complex

The dihydride ruthenium N‐heterocyclic carbene complex Ru(IMes)(PPh₃)₂CO(H)₂ ( 1 ) (IMes=1,3‐dimesityl‐1,3‐dihydro‐2H‐imidazol‐2‐ylidene) is an efficient catalyst for both direct hydrogenation and transfer hydrogenation of ketones and imines, in the absence of base.