cis/trans-Isomerisation of triolein,trilinolein and trilinolenin induced by heat treatment

To estimate the trans-fatty acid production of edible oils during the frying process, 1.0 g of triolein, trilinolein and trilinolenin, as representative oils, were heated at 180 °C for a defined period. The amounts of trans-fatty acids in heated triacylglycerols were quantitatively determined by gas chromatography after methylation. It was revealed that heating induced cis to trans-isomerisation of unsaturated triacylglycerols, and that trans-fatty acid amounts increased gradually, depending on the heating period. For example, trans-isomer amounts in triolein, trilinolein and trilinolenin (per gram) were 5.8 mg, 3.1 mg and 6.5 mg, respectively, after 8 h incubation at 180 °C. At that time, the contents of polar compounds contained in the heated triolein, trilinolein and trilinolenin were 22%, 27% and 31%, respectively. When triolein was heated under a N₂ stream, neither trans-isomerisation nor polar compounds were detected. The addition of α-tocopherol (1.0%) to triolein significantly prevented not only lipid oxidation but also trans-isomerisation during heating. A commercially available vegetable oil was also heated under the same conditions as these model oils. Compared with the trans-isomerisation in model oils, the degree of trans-isomerisation in the edible oil was relatively low. Tocopherols in the oil would prevent not only lipid oxidation but also isomerisation. These results suggest that the geometric isomerisation of unsaturated fatty acids during heating accompanies lipid oxidation.     

Uptake and utilization of ectoine by halotolerant Brevibacterium sp. JCM 6894 subjected to osmotic downshock

The concentration changes of the cyclic amino acid ectoine (1,4,5,6-tetrahydro-2-methyl-4-pyridine carboxylic acid) in Brevibacterium sp. JCM 6894 cells subjected to an osmotic downshock were investigated. When the cells grown in the presence of 2 M NaCl were suspended in deionized water, they immediately released about 60% of the ectoine synthesized intracellularly. During the subsequent incubation, we observed that both the extra- and intracellular concentrations of ectoine were reduced almost linearly with the incubation time. When ectoine was provided externally to the downshocked cells, a similar reduction in both intra- and extracellular ectoine concentrations was recognized. In addition, we observed an increase in ectoine accumulation at about 10 h of incubation, which indicates that ectoine was taken up by such downshocked cells in the absence of external Na+. Furthermore, the downshocked cells showed higher levels of survival, respiration, and growth in the presence of ectoine than in its absence. The ability to take ectoine up was induced in the cells grown in the presence of >0.25 M NaCl for >12 h. Thus, we conclude that even under the lower osmotic condition ectoine might be taken up and subsequently utilized by strain JCM 6894 subjected to the osmotic downshock, indicating that the uptake of ectoine by such cells occurred for the survival and growth of the cell itself rather than for cellular osmoregulation.     

Production of fruiting-body lectins of Pleurotus cornucopiae in methylotrophic yeast Pichia pastoris

Fruiting-body lectin genes obtained from Pleurotus cornucopiae were expressed in Pichia pastoris Because of glycosylation of the products, their molecular mass was larger than that of the corresponding native lectins. They showed binding activity to porcine stomach mucin in the enzyme-linked lectin assay system, but did not agglutinate red blood cells.     

Comparison of Centralized and Decentralized Systems in Power System Restoration

This paper proposes a multiagent approach to decentralized power system restoration for distribution system networks and presents a comparison of centralized and decentralized systems for power system restoration. Numerous studies have been conducted on power system restoration problems. From the viewpoint of system structures, this research can be divided into two categories: centralized systems and decentralized systems. In this study, we solve a power system restoration problem for a power distribution network by two different methods: mathematical programming (MIP) and the proposed multiagent‐based method (MAS). The proposed multiagent system consists of several distributing substation agents (DSAGs) and load agents (LAGs). An LAG corresponds to the customer load, and a DSAG supplies electricity to the LAG. From the simulation results, it can be seen that the proposed system can reach the right solution by making use of only local information and that the solution quality is better than that of the centralized system (MIP). This means that the proposed multiagent restoration system is a promising approach to larger scale distribution networks.     

Network copolyesters from benzenepolycarboxylic acids and 1,6-hexanediol

Network copolyesters were prepared from trimesic (Y), pyromellitic (X) or mellitic (Y_H) acids and 1,6-hexanediol (6G). Prepolymers prepared by meltpolycondensation were cast from dimethylformamide solution and postpolymerized at 260°C for 6h to form a network. The resultant films were transparent, flexible and insoluble in any organic solvents. Degree of reaction estimated from the infrared absorbance of ester and methylene groups was almost the same for all films, 94–96%. X-ray diffraction intensity curves and densities showed that the ordering of networks was decreased by the copolymerization, which was remarkable for 6G–X/Y_H copolymer films and was consistent with the higher decreases of heat-distortion temperature for these copolymer films. The copolymerization also caused decrease of thermal stability, tensile properties and alkali resistance and increase of dye absorption.     

A new maritime lifesaving multiple-effect solar still design

This paper presents a new maritime lifesaving multiple-effect solar still design where several extended wicks feed seawater to their evaporating areas by capillary force, and the resulting water vapor diffuses and condenses on facing wicks with the condensate flowing through the wicks into storage bags. A theoretical analysis showed that a temperature drop through diffusion layers between evaporating and condensing wicks slowly increases in the main evaporating areas and rapidly near salt depositions whereas the evaporation rate decreases slowly in the main area and rapidly near salt depositions. These changes are caused by increases in salt concentrations and resulting boiling point elevation. With steady-state transfer analysis, the proposed still is predicted to produce about 15 kg m ⁻²d⁻¹ fresh water on a sunny day of 22 MJm⁻²d⁻¹ solar radiation, showing a potential to be a maritime lifesaving desalinator.     

Dietary Guar Gum Reduces Lymph Flow and Diminishes Lipid Transport in Thoracic Duct-Cannulated Rats

Guar gum has a well-recognized hypolipidemic effect. This effect is thought to be due to the physicochemical properties of guar gum, which may cause changes in adsorption of lipids or the viscosity of the intestinal contents. Guar gum is a non-specific absorption inhibitor of any type of lipid-soluble compound. Permanent lymph duct cannulation was performed on rats to investigate the effects of dietary guar gum on lymph flow and lipid transport. Rats fed a 5% guar gum diet were compared with those fed a 5% cellulose diet, and lymph was collected after feeding. The water-holding capacity (WHC), settling volume in water (SV), and viscosity of guar gum were compared with those of cellulose. Rats fed with the guar gum diet had significantly lower lymph flow and lymphatic lipid transport than did rats fed with the cellulose diet. The WHC, SV, and viscosity of guar gum were significantly higher than those of cellulose. We propose that dietary guar gum reduces lymph flow and thereby diminishes lipid transport by means of its physicochemical properties related to water behavior in the intestine.     

An optical field-induced ionization X-ray laser using a preformedplasma scheme

Soft X-ray amplification by optical field-induced ionization (OFI) of a preformed plasma is investigated. A small-signal gain of 20 cm^-1 and a gain-length product of 4 at 13.5 nm on the Lyman-α transition in hydrogen-like lithium have been obtained using the modified OFI scheme. Experimental and numerical results ensure that we have produced a plasma with a significantly lower electron temperature than what is expected by an above-threshold ionization model. To explain the results, a two component plasma model in which relatively high temperature electrons are produced by OFI in a cold electron bath of the preformed plasma is presented. The model indicates that the average electron temperature of the OFI plasma rapidly decreases since a high-temperature part of the electrons escapes from the focal volume without interaction. The initial electrons produced prior to the field ionization, which survive after the OEI, also significantly contribute to the rapid three-body recombination. Based on the ionization-induced refractive index change, the pulse propagation of a high-intensity pump laser during the OFI is also discussed     

Chemical transformation of chiral monolayer-protected gold clusters: observation of ligand size effects on optical and chiroptical responses

Versatile functionalization of metal clusters is a key step in understanding the reactivity of protective monolayers. We here demonstrate that reaction of the outermost amino groups on (S)-/(R)-penicillamine-protected gold clusters with ethyl isocyanate readily modifies the chiral surface structure through carbamoylation. Interestingly, the clusters are electrophoretically separated by the size of the surface ligand, not by the size of the gold core, which is revealed by UV-vis, IR, and energy dispersive X-ray (EDX) spectroscopy as well as SAXS measurements. The ligand size (or length) is extended through additional reactions of the carbamoylated amino groups with isocyanate, while the chemical similarity in ligand structures is realized by their IR spectral similarity. Optical and chiroptical responses of the separated cluster compounds are thus overall similar to each other, but a close inspection reveals that the ligand size has a small but distinct influence on the chiroptical response of the gold clusters.