Re-assembled casein micelles and casein nanoparticles as nano-vehicles for ω-3 polyunsaturated fatty acids

Food enrichment with nutraceuticals is an important goal, but its effectiveness in preventing diseases depends on preserving the functionality and bioavailability of the bioactive nutraceuticals. Omega-3 polyunsaturated fatty acids, such as docosahexaenoic acid (DHA), are important nutraceutical lipids, providing protection against cardiovascular and other diseases. Caseins are the major milk proteins whose biological function is to transport calcium, protein and phosphate from mother to the neonate. Our goal was to harness the natural self-assembly properties of caseins for protecting and delivering this important, but sensitive nutraceutical, DHA. Using spectrofluorescence we have shown, apparently for the first time, that casein can bind DHA with a relatively high affinity (K_b = (8.38 ± 3.12) × 10⁶ M⁻¹), and the binding ratio was 3–4 DHA molecules per protein molecule on average. Moreover, DLS particle characterization experiments have shown the formation of nanoparticles upon addition of DHA (predissolved in ethanol) to a casein solution. When calcium and phosphate were added (at 4 °C), DHA-loaded re-formed casein micelles (r-CM) with a size of 50–60 nm were obtained and there was no significant effect of the thermal treatment (74 °C, 20 s) on particle size. When casein nanoparticles (CNP) were prepared (at room temperature and without adding calcium and phosphate), DHA-loaded CNP with a diameter of 288.9 ± 9.6 nm were formed. Both the DHA-loaded r-CM and the DHA-loaded CNP systems showed a remarkable protective effect against DHA oxidation, demonstrating good colloidal stability and bioactive conservation throughout shelf life at 4 °C. These nanotechnologies may enable the enrichment of foods and beverages for promoting health of wide populations.     

Decay of the HO2 and O−2 Radicals Catalyzed by Superoxide Dismutase. A Pulse Radiolytic Investigation

The pulse radiolysis technique has been employed in the investigation of the dismutation of superoxide radicals, O^?₂ and HO₂, in the presence of superoxide dismutase in aqueous solutions. The decay of superoxide radicals in the presence of the enzyme was found to be first order in both enzyme and superoxide concentrations. An apparent second order reaction rate constant was found to be about 2 × 10⁹ M^?1 sec^?1, decreasing slightly as the pH is increased from 5 to 9.5. A mechanism which accounts for all our observations is proposed. It includes two steps: (1) formation of a product (EO^?₂ or E^?) from one enzyme (E) molecule and one O^?₂ radical ion; (2) regeneration of E by a reaction of this product with an additional O^?₂ ion radical. The reaction rate constants k = (1.4 ± 0.2) × 10⁹ and k = (1.9 ± 0.6) × 10⁹ M^?1 sec^?1 were measured at pH = 7 in an oxygenated 0.16 M sodium formate solution.     

Life cycle assessment of Jatropha biodiesel as transportation fuel in rural India

Since 2003 India has been actively promoting the cultivation of Jatropha on unproductive and degraded lands (wastelands) for the production of biodiesel suitable as transportation fuel. In this paper the life cycle energy balance, global warming potential, acidification potential, eutrophication potential and land use impact on ecosystem quality is evaluated for a small scale, low-input Jatropha biodiesel system established on wasteland in rural India. In addition to the life cycle assessment of the case at hand, the environmental performance of the same system expanded with a biogas installation digesting seed cake was quantified. The environmental impacts were compared to the life cycle impacts of a fossil fuel reference system delivering the same amount of products and functions as the Jatropha biodiesel system under research. The results show that the production and use of Jatropha biodiesel triggers an 82% decrease in non-renewable energy requirement (Net Energy Ratio, NER = 1.85) and a 55% reduction in global warming potential (GWP) compared to the reference fossil-fuel based system. However, there is an increase in acidification (49%) and eutrophication (430%) from the Jatropha system relative to the reference case. Although adding biogas production to the system boosts the energy efficiency of the system (NER = 3.40), the GWP reduction would not increase (51%) due to additional CH₄ emissions. For the land use impact, Jatropha improved the structural ecosystem quality when planted on wasteland, but reduced the functional ecosystem quality. Fertilizer application (mainly N) is an important contributor to most negative impact categories. Optimizing fertilization, agronomic practices and genetics are the major system improvement options.     

Social desirability effects on computerized and paper-and-pencil questionnaires

The objectives of the present study were to determine the impact of computer administration of questionnaires on impression management (IM) and self-deceptive enhancement (SDE) and on the disclosure of sensitive information such as alcohol use and risky sex. College students (N = 301) completed several questionnaires in either a computer-administered or paper-and-pencil condition. Respondents who completed the survey on the computer scored significantly higher on SDE than those completing the survey on paper. No differences were found for IM. Respondents in the computer condition also reported a higher level of alcohol consumption and riskier sexual behaviors than those in the paper-and-pencil condition. It is possible that computer administration of surveys creates a social situation that produces a sense of disinhibition in respondents, and this sense of disinhibition may lead to greater reports of risky behaviors.     

Membrane‐Surface Anchoring of Charged Diacylglycerol‐Lactones Correlates with Biological Activities

Synthetic diacylglycerol‐lactones (DAG‐lactones) are effective modulators of critical cellular signaling pathways, downstream of the lipophilic second messenger diacylglycerol, that activate a host of protein kinase C (PKC) isozymes and other nonkinase proteins that share similar C1 membrane‐targeting domains with PKC. A fundamental determinant of the biological activity of these amphiphilic molecules is the nature of their interactions with cellular membranes. This study examines the biological properties of charged DAG‐lactones exhibiting different alkyl groups attached to the heterocyclic nitrogen of an α‐pyridylalkylidene chain, and particularly the relationship between membrane interactions of the substituted DAG‐lactones and their respective biological activities. Our results suggest that bilayer interface localization of the N‐alkyl chain in the R² position of the DAG‐lactones inhibits translocation of PKC isoenzymes onto the cellular membrane. However, the orientation of a branched alkyl chain at the bilayer surface facilitates PKC binding and translocation. This investigation emphasizes that bilayer localization of the aromatic side residues of positively charged DAG‐lactone derivatives play a central role in determining biological activity, and that this factor contributes to the diversity of biological actions of these synthetic biomimetic ligands.     

Formation Routes of Nanocomposite Coatings in Detonation Spraying of Ti3SiC2-Cu Powders

In thermally sprayed coatings, nano-sized features of the microstructure may be either inherited from the nanostructured agglomerates of the feedstock powder or form as a result of rapid cooling of molten particles upon deposition. Applying a process of the computer-controlled detonation spraying (CCDS) to Ti₃SiC₂-Cu composite powders produced by high-energy mechanical milling, we show that both routes are possible depending on the spraying conditions. When the nanostructure of the Ti₃SiC₂-Cu coating is inherited from the feedstock powder—under very mild conditions of detonation spraying, which exclude melting, so is the phase composition of the coating. In higher-temperature conditions of spraying, a significant fraction of the copper matrix melts and the interaction between Ti₃SiC₂ and Cu occurs. The TiC _x -Cu(Si) coatings that form show crystallites of both phases in the nano-range. In this case, rapid solidification of the molten fraction of the particles is responsible for the formation of the coatings with a nanostructured matrix. Due to the flexibility of the CCDS process, conditions of spraying were found such that a composite coating with very fine crystallites of the Cu(Si) matrix (30 nm) and a hardness of 273 HV could be obtained.     

Influence of Surface Topography on the Tribological Behaviour of Aluminium Alloy 5182 with EDT Surface

Friction is one of the most important parameters in sheet metal forming. Friction conditions are influenced by the texture of the sheet surface, by the surface or coating of the tools and by the lubrication. The aluminium alloy AA 5182 with EDT surface has been studied and tested at various angles between rolling and sliding direction. The friction behaviour observed in experiments at different normal pressures based on Coulomb’s friction law are shown and discussed in this article. Moreover, local surface topography and lubricant distribution in the contact area are described.     

Use of Time Series Analysis to Evaluate the Impacts of Underground Mining on the Hydraulic Properties of Groundwater of Dysart Woods,Ohio

Mine Water and the Environment - Dysart Woods is the largest (≈ 23 ha) old-growth forest in southeastern Ohio. It was donated to Ohio University for research purpose and public...     

Depressive symptomatology in maritally discordant women and men: The role of individual and relationship variables.

Marital discord and depressive symptomatology have repeatedly been found to be associated, but little is known about variables that influence this relationship. Data were collected from 139 couples seeking marital therapy, and analyses were conducted separately by gender. For wives, lower problem-solving ability, physical aggression by the partner, and 1 relationship belief predicted depressive symptomatology after the variance due to marital discord was removed in regression analyses. In addition to these predictors, less spouse-specific assertiveness, unemployment, and 1 other relationship belief were associated with depressive symptomatology for women after the variance due to marital discord was removed in partial correlation analyses. For men, only lower problem-solving ability added to the prediction of depressive symptomatology. (PsycINFO Database Record (c) 2010 APA, all rights reserved)