Preservation of freshness of rainbow trout fillets packaged with carbon dioxide-nitrogen gas mixture (studies on gas-exchange packaging of fresh fish,part 2)

Gas-exchange packaging was applied to preserve freshness of rainbow trout fillets. The fillets were packaged in pouches of coextruded laminate (ethylene vinyl acetate/ polyvinylidene chloride-polyolefin) with a carbon dioxide-nitrogen gas mixture (N₂ : CO₂ = 6 : 4). Other fillets were wrapped with polyvinyl chloride film as a reference group. Changes in sensory score of colour and flavour, K-value and bacterial counts of the fillets were investigated during storage at 5°C. After 2 days the fillets wrapped with polyvinyl chloride film lost their gloss. In addition, an amine-like odour was detected after 3 days. The gas-packaged fillets, however, showed little change in colour, flavour and bacterial counts, and retained their fresh appearance for 3 days.     

Lifespan extension by caloric restriction: an aspect of energy metabolism

Caloric restriction (CR) may retard aging processes and extend lifespan in organisms by altering energy-metabolic pathways. In CR rodents, glucose influx into tissues is not reduced, as compared with control animals fed ad libitum (AL), although plasma concentrations of glucose and insulin are lower. Gene expression profiles in rodents have suggested that CR promotes gluconeogenesis and fatty acid biosynthesis in skeletal muscle. In the liver, CR promotes gluconeogenesis but decreases fatty acid synthesis and glycolysis. In lower organisms such as yeasts and nematodes, incomplete blocks in steps of insulin/insulin-like growth factor-1 (IGF-1) signal pathway extend lifespan. The life-prolonging effect of CR in yeasts requires NPT1 and SIR2 genes, both of which relate to sensing energy status and silencing genes. These findings stress the substantial role of energy metabolism on CR. Future studies on metabolic adaptation and gene silencing with regard to lower caloric intake will be warranted to understand the mechanisms of the anti-aging and life-prolonging effects of CR.     

Electrogenerated chemiluminescence. 68. Detection of sodium ion with a ruthenium(II) complex with crown ether moiety at the 3,3'-positions on the 2,2'-bipyridine ligand

We show here how a Ru(bpy)2(CE-bpy) complex can be used for the ECL detection of sodium ion in both aqueous and nonaqueous media. Recognition of Na+ by the crown ether moiety in CE-bpy results in a significant increase in the ECL emission intensity of the complex.     

State-of-the-Art on numerical simulation of fiber-reinforced thermoplastic forming processes

Summary Short fiber reinforced composites have gained increasing technological importance due to their versatility that lends them to a wide range of applications. These composites are useful because they include a reinforcing phase in which high tensile strengths can be reached, and a matrix that allows to hold the reinforcement and to transfer applied stress to it. It is a well-known fact, that such materials can have excellent mechanical, thermal and electrical properties that make them widely used in industry. During the manufacture process, fibers adopt a preferential orientation that can vary significantly across the geometry. Once the suspension is cooled or cured to make a solid composite, the fiber orientation becomes a key feature of the final product since it affects the elastic modulus, the thermal and electrical conductivities, and the strength of the composite material. In this work we analyzed the state-of-the-art and the recent developments in the numerical modeling of short fiber suspensions involved in industrial flows.     

Analysis and characteristics of a permanent magnet-type bearingless motor

Super-high-speed and high-power electric machines are required for turbomolecular pumps and spindle drives. High rotational speed and high-power drives can be achieved with bearingless motors. In this paper, a bearingless motor with principles of permanent magnet-type synchronous motors is proposed. High-power factor and high efficiency can be expected in permanent magnet-type bearingless motors. The proposed bearingless motor is a 4-pole permanent magnet synchronous motor, in which additional 2-pole windings are wound together with 4-pole motor windings in stator slots. With currents of 2-pole windings, radial magnetic forces are produced to support a rotor shaft. Principles of radial force production of surface-mounted permanent magnet bearingless motors are analyzed mathematically. The relationships between radial forces and the permanent magnet thickness were derived. From these relationships, the optimal permanent magnet thickness to produce radial forces efficiently is found. A test machine was built to confirm the relationships of radial forces, currents and voltages.     

Digital input filters for measurement,control and protection of electric power systems

Power system control and protection equipment has required higher sensitivity and operational reliability than conventional one. Studies of digital signal processing suitable for electric power systems fulfill this objective using fast sampling and digital filtering by a 32-bit floating point DSP (Digital Signal Processor). The sampling rate of 3 kHz is carefully selected in order to separate the power spectrums of the A-D conversion output errors from the signal bandwidth. The new 12-bit A-D conversion unit equipped with a recursive-type digital filter achieved the equivalent high resolution of 14-bit conversion. This paper describes the design concept and the characteristics showing applications to current differential relays, distance relays and power system controllers.     

Microtiter plate immunoassay for the evaluation of platelet adhesion to fibronectin

This study shows the effects of a selective endothelin ET(B) receptor agonist, IRL 1720 {Ac-[Ala11,15]endothelin-1-(8-21)}, on cardiovascular responses in anesthetized spontaneously hypertensive rats and Wistar-Kyoto rats. Single intravenous bolus injection of IRL 1720 caused a dose-related short-lasting fall in blood pressure, left ventricular pressure and myocardial contractility. However, repeated intravenous bolus injection of 10(-5) mol/kg IRL 1720 produced a biphasic response consisting of an initial short-lasting decrease followed by a sustained increase in these parameters. The initial decrease was reduced, whereas the following increase was enhanced with the repeated injections of IRL 1720. The cardiovascular pressor response was not inhibited by the endothelin ET(A) receptor antagonist, FR139317 ((R)2-[(R)-2-[(S)-2-[[1-(hexahydro-1H-azepinyl)]carbonyl] amino-4-+methylpentanoyl] amino-3-[3-(1-methyl-1H-indolyl)]propionyl]amino -3- (2-pyridyl)propionic acid). The effects of IRL 1720 were qualitatively similar but more potent in spontaneously hypertensive rats than in Wistar-Kyoto rats. These results suggest the existence of two types of endothelin ET(B) receptor for IRL 1720: a tachyphylactic endothelin ET(B) receptor that mediates cardiovascular depressor responses and a less tachyphylactic endothelin ET(B) receptor that mediates pressor responses in the rat.     

Chemical reactions in foods II

Chemical reactions in foods II