Oxidation progress in an emulsion made from metmyoglobin and different triacylglycerols

Emulsions made using metmyoglobin as emulsifier and different synthetic and natural triacylglycerols (TAG), have been studied with respect to oxidation progress during 48 h at ambient temperature. The investigated model systems contained polyunsaturated TAGs of linolein (C18:2n-6, tri-LIN), arachidonin (C20:4n-6, tri-ARA), docosahexanoin (C22:6n-3, tri-DHA), salmon oil (SO) and cod liver oil (CLO). The synthetic TAGs were added in ratios of one part to nine parts trioctanoin (C8:0), yielding model composite oil systems. The total amount of volatiles, determined using dynamic headspace GC/MS, were relatively larger for tri-LIN and tri-ARA than for the marine systems during the first 6 h of observation. After 48 h of incubation, the marine oils had more total volatiles than had tri-LIN and tri-ARA. Hexanal and propanal were observed as the marker degradation compounds for n-6 and n-3 fatty acids, respectively. Myoglobin tended to aggregate in these model systems, and only for trioctanoin and tri-LIN could the protein monomer be recovered unmodified and subsequently observed using MALDI-TOF MS after 48 h of incubation. Myoglobin was only recovered after 4 h of incubation in the tri-DHA system, and it then appeared adducted with lipid fragments up to ∼1000 Da. Final oxidation (after 48 h) products from the marine lipids were trienes, most likely as alcohols or acids. The natural oils revealed a reaction pattern close to that of tri-DHA.     

Hole‐rich host materials for blue‐phosphorescent OLEDs

Abstract— Stable and efficient organic light‐emitting devices (OLEDs) are an integral part of the future of lighting and displays. The hole accumulation at the hole‐transport/emissive‐layer interface in such devices is considered to be a major pathway for degradation and efficiency loss. Here, the design and synthesis of two charge‐transporting host materials, based on the phosphine oxide (PO) moiety, engineered to improve hole transport of the emissive layer, will be reported. The compounds are an extension of a molecular design strategy which incorporates a hole‐transporting moiety and an electron‐transporting moiety. These materials were designed with two hole‐transport moieties (HTms) to further improve hole transport, compared to the first‐generation host materials that were designed with one hole‐transport functional group. The triplet exciton energy was maintained at a level greater than that of FIrpic (2.7 eV) to prevent exciton quenching. The EHOMO and ELUMO of the two classes of molecules (i.e., 1 HTm vs. 2 HTms) were similar; however, their device performance varied greatly. Emission zone experiments were conducted to further characterize the difference in charge transport between the molecules.     

Modelling of furniture experiments with zone models

The Harvard Computer Fire Code Mark V has been used to simulate full-scale furniture fires. Simulations were run with one sofa burning in the open and another burning in a small room. To obtain better agreement between experiment and simulation, changes were made in the code to include heating of the lower surfaces in the room. A simulation of a mattress test, conducted at NBS, is included. Comparison with a zone model using a different plume equation is also presented.     

A respectable old age.

The author outlines events that led to his interest in aging. His involvement with older people has revealed that too little is known about the later stages of life and the problems with which older people must cope and too few methods of helping them cope with these problems are available. The absolute number of the over-65 yrs cohort and their percentage of the total population are increasing rapidly. This increase in their numbers will force a structural change in society so that the over-65 yrs cohort will be more integrated into the social structure and will participate more actively in all aspects of society. This change will generate a number of problems for psychologists to solve. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Compositional Factors that Influence Lipid Peroxidation in Beef Juice and Standard Sausages

In order to identify how different additives influenced lipid peroxidation formation, a sausage only using beef juice as pigment source and a standard beef–pork meat sausage were studied. The effects of different additives, including fish oil, myoglobin, nitrite, clove extract, and calcium sources on oxidation and sensory properties were examined. Both sausage systems were stored in 3 different manners prior to testing: (1) frozen immediately at ?80 °C; (2) chilled stored for 2.5 weeks followed by fluorescent light illumination at 4 °C for another 2 wk; (3) frozen at ?20 °C for 5 mo. The frozen group 3 showed the highest peroxide formation and thiobarbituric acid reactive substances (TBARS) for both sausage systems. Unpolar peroxides dominated in both systems. The clove extract could offset the peroxide formation from myoglobin/beef juice and/or fish oil, but the addition of clove flavor was recognized by the sensory panelists. Calcium addition reduced lipid peroxide formation. Added nitrite and fish oil seemed to interact to stimulate nitroso‐myoglobin formation. Nitrite was identified to interact with clove addition and thereby, relatively speaking, increased TBARS. The 2 sausage systems generally ranked the additives similarly as pro– and antioxidants.     

Emissions of ultrafine particles from five types of candles during steady burn conditions

Emissions from candles are of concern for indoor air quality. In this work, five different types of pillar candles were burned under steady burn conditions in a new laboratory scale system for repeatable and controlled comparison of candle emissions (temperature ~25°C, relative humidity ~13%, O₂ >18%, air exchange rate 1.9 h⁻¹). Burn rate, particle number concentrations, mass concentrations, and mode diameters varied between candle types. Based on the results, the burning period was divided in two phases: initial (0–1 h) and stable (1–6 h). Burn rates were in the range 4.4–7.3 and 4.7–7.1 g/h during initial and stable phase, respectively. Relative particle number emissions, mode diameters, and mass concentrations were higher during the initial phase compared to the stable phase for a majority of the candles. We hypothesize that this is due to elevated emissions of wick additives upon ignition of the candle together with a slightly higher burn rate in the initial phase. Experiments at higher relative humidity (~40%) gave similar results with a tendency toward larger particle sizes at the higher relative humidity. Chemical composition with respect to inorganic salts was similar in the emitted particles (dry conditions) compared to the candlewicks, but with variations between different candles.     

Do cereal mixed‐linked β‐glucans possess immune‐modulating activities?

β‐glucans are known for their immune‐modulating properties. However, the heterogeneity of these glucose polymers makes a distinction between the different sources and structures necessary—a fact that has been little allowed for in the literature. We have focused on β‐glucans from cereals as they are already used as functional food ingredients due to their established cholesterol lowering effect. Cereal β‐glucans have shown in vitro activity on cytokine secretion, phagocytic activity and cytotoxicity of isolated immune cells, and activation of the complement system. Animal studies suggest a possible protective effect against an intestinal parasite, against bacterial infection, and a synergistic effect in antibody‐dependent cellular cytotoxicity. Animal studies have shown activity of orally applied cereal β‐glucans indicating uptake or interaction with cells of the gastrointestinal tract. However, uptake is still debated, interaction with intestinal epithelial cells has been suggested but not clarified, and mechanisms of action remain largely unknown. So far, cereal β‐glucans have not shown immune modulation in the few conducted human studies and further studies are needed to clarify their effect.     

Optimization of ordered plasmid assembly by gap repair in Saccharomyces cerevisiae

Combinatorial genetic libraries are powerful tools for diversifying and optimizing biomolecules. The process of library assembly is a major limiting factor for library complexity and quality. Gap repair by homologous recombination in Saccharomyces cerevisiae can facilitate in vivo assembly of DNA fragments sharing short patches of sequence homology, thereby supporting generation of high‐complexity libraries without compromising fidelity. In this study, we have optimized the ordered assembly of three DNA fragments into a gapped vector by in vivo homologous recombination. Assembly is achieved by co‐transformation of the DNA fragments and the gapped vector, using a modified lithium acetate protocol. The optimal gap‐repair efficiency is found at a 1:80 molar ratio of gapped vector to each of the three fragments. We measured gap‐repair efficiency in different genetic backgrounds and observed increased efficiency in mutants carrying a deletion of the SGS1 helicase‐encoding gene. Using our experimental conditions, a gap‐repair efficiency of > 10⁶ plasmid‐harbouring colonies/µg gapped vector DNA is obtained in a single transformation, with a recombination fidelity > 90%. Copyright © 2012 John Wiley & Sons, Ltd.