ALBERT

Notes: : In vitro antioxidant and antibacterial protection of shallot and scallion were examined. Water extract and oil of shallot and scallion significantly delayed lipid oxidation in multilamellar phosphatidylcholine liposomes and human RBC membranes (p 〈 0.05). Shallot oil at 5 and 10 mM showed marked antioxidant activity at 75 °C (p 〈 0.05). Shallot and scallion oils significantly inhibited the growth of 4 food-borne bacteria, Salmonella typhimurium DT104, E.coli O157:H7, Listeria monocytogenes and Staphylococcus aureus, and 4 nosocomial bacteria, methicillin-resistant Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii (p 〈 0.05). All observed antioxidant and antibacterial activities were dose-dependent (p 〈 0.05). These results suggested the use of shallot and scallion oils in food systems could enhance lipid and microbial stability.

Notes: The vapor pressures of acetaldehyde, diacetyl, ethyl benzene, ethyl caproate, ethyl heptanoate, ethyl sulfide, hexanal, trans-2-hexenal, D-limonene, octanone, 1-pentanol, 2-pentanone, and styrene (50 ppm each) over a vegetable oil emulsion, water or selected fat replacer (aqueous solutions, 37°C) was monitored. The five fat replacers were a whey-based and an egg based microparticulated protein, a pregelatinized tapioca maltodextrin, microcrystalline cellulose (MCC) and a MCC/carboxymethyl cellulose blend. The flavor compounds interacted with oil in a predictable manner following Raoult's Law. The fat replacers generally had little influence on vapor pressure of the flavor compounds behaving as in a water system except for the Simplesse products which had substantial interaction with aldehydes.

Notes: Summary The strong excitatory activity of L-glutamic acid on central nervous system neurons is thought to be produced by interaction of this amino acid with specific neuronal plasma membrane receptors. The binding of L-glutamate to these surface receptors brings about an increase in membrane permeability to Na+ and Ca2+ ions presumably through direct activation of ion channels linked to the membrane receptors. The studies described in this paper represent attempts to define the subcellular distribution and pharmacological properties of the recognition site for L-glutamic acid in brain neuronal preparations, to isolate and explore the molecular characteristics of the receptor recognition site, and, finally, to demonstrate the activation of Na+ channels in synaptic membranes following the interaction of glutamate with its receptors. Radioligand binding assays with L-[3H] glutamic acid have been used to demonstrate a relative enrichment of these glutamate recognition sites in isolated synaptic plasma membranes. The specific binding of L-[3H] glutamate to these membrane sites exhibits rapid association and dissociation kinetics and rather complex equilibrium binding kinetics. The glutamate binding macromolecule from synaptic membranes has been solubilized and purified and was shown to be a small molecular weight glycoprotein (MT ≈ 13 000). This protein tends to form aggregates which have higher specific activity at low concentrations of glutamate than the MT 13 000 protein has. The overall affinity of the purified protein is lower than that of the high affinity sites in the membrane. Nevertheless, the purified protein exhibits pharmacological characteristics very similar to those of the membrane binding sites. On the basis of its pharmacological properties this protein belongs in the category of the physiologic ‘glutamate preferring’ receptors. By means of differential solubilization of membrane proteins with Na-cholate, it was shown that this recognition site is an intrinsic synaptic membrane protein whose binding activity is enhanced rather than diminished by cholate extraction of the synaptic membranes. The role of membrane constituents in regulating the binding activity of this protein has been explored and a possible modulation of glutamate binding by membrane gangliosides has been demonstrated. Finally, this glutamate binding glycoprotein is a metalloprotein whose activity is dependent on the integrity of its metallic (Fe) center. This is a clear distinguishing characteristic of this protein vis-à-vis the glutamate transport carriers. The presence of functional glutamate receptors in synaptosomes and resealed synaptic plasma membranes has also been documented by the demonstration of glutamate-activated Na+ flux across the membrane of these preparations. The bidirectionality, temperature independence, and apparent desensitization of this stimulated flux following exposure to high concentrations of glutamate are properties indicative of a receptor-initiated ion channel activation. It would appear, then, that the synaptic membrane preparations provide a very useful system for the study of both recognition and effector function of the glutamate receptor complex.

Notes: Resumen Se describe la sintesis y prueba de estructura del 3-acetato de (20 S, 21 R)-3β-hidroxi-21-amino-14β, 21-oxidonorcolan-23-oico ácido lactama, el cúal es el derivativo lactama de digitoxigenina. Dicho compuesto posée insignificantes efectos inotrópicos, pero inhibe o retarda la acción inotrópica positiva del 3-acetato de digitoxigenina cuando se ensaya en atria izquierda aislada de cochinillo de Indias o conejo.

Notes: Abstract We undertake a study where we examine changes in the profitability, productivity and price recovery of firms in the U.S. telecommunications industry over a sixteen-year period. We assess the performance of thirty-three major companies in the local-exchange sector over six time periods 1975, 1978, 1981, 1984, 1987 and 1990, using a performance analysis model which disaggregates the profitability measure into two components: productivity and price recovery. We demonstrate the computation of performance using this technique. Our study indicates that the opening up of markets has had a significant impact on different dimensions of performance in the telecommunications industry, also validating a number of theoretical assumptions about the impact that industry changes are expected to have on firms.

Notes: PV Fast Maroon HFM based polyurethane ionomers were successfully synthesized at our lab, and these ionomer structures have been proven by infrared spectra. In aqueous solution, the surface tension was found to be lower for the HFM pigment-based polyurethane ionomer made by toluene diisocyanate (TDI), as a result of more hydrophobicity adsorbed at the surface of aqueous solution. The viscosity decreases with increasing the concentration of the HFM pigment used to prepare the HFM pigment based polyurethane ionomer, indicating that the structure of this ionomer is possibly considered to be a type of micelle. In addition, the number-average particle sizes are seen to be decreased with increasing the concentration of HFM pigment employed for making the HFM pigment based polyurethane ionomer. These results also suggest that the HFM pigment based polyurethane ionomer molecule could have a micelle-like sturcture. However, the 100% modulus property for both the IPDI type or the TDI type of PV Fast maroon HFM based PU ionomer molecules appears to increase gradually with increasing the concentration of HFM, as a result of more crosslinking formed. ©1996 John Wiley & Sons, Inc.