Allergic Skin Reactivity and Chemical Properties of Allergens in Two Grades of Lactose

Skin tests of the nondialyzable fraction of lactose were performed on patients with a clinical diagnosis of cow's milk allergy. The yields of brownish-colored residue, allergens (ALG), were 0.006% from reagent grade lactose (ALG 1) and 0.011% from lactose used in a commercial infant food formula (ALG 2). The ALG was separated into four fractions by chromatography on Sephadex G-75. The highest incidences of positive skin reaction among the four ALG 1 and ALG 2 fractions were 8/9 and 8/12 respectively. The ALG fractions were identified as a sugar protein complex and the protein moiety of ALG contained high amounts of glutamic acid (or glutamine), threonin, asparagic acid (or asparagine) and proline.     

Mechanism of Ni-Zn Ferrite Formation in the Presence of Molten Li2SO4-Na2SO4

Nickel-zinc ferrite powder was prepared from the constituent oxides in the presence of molten Li₂SO₄-Na₂SO₄. The effect of ZnO on the reactivity of NiO was studied. The process of Ni-Zn ferrite formation was followed by X-ray diffraction and thermomagnetic analyses. Particle size and shape of the product were determined by scanning electron microscopy. In the presence of molten salt, ZnO enhances the reactivity of NiO, and Ni-Zn-ferrite formation is completed at lower temperature than Ni ferrite formation. In the reaction for the formation of Ni-Zn ferrite, Zn ferrite forms before NiO is incorporated into the ferrite phase. The reaction between the initially formed Zn ferrite and NiO leads to a rate of Ni-Zn ferrite formation higher than that of Ni ferrite formation from NiO and Fe₂O₃.     

Bioleaching of Sulfide Mineral in Stirred Tank Reactors Operated in a Variety of Modes

Abstract

This paper reviews analysis and modeling for the bioleaching of pyrite in stirred tank reactors operated in a variety of modes: batch, repeated-batch and continuous flow. In a batch reactor, rate data were consistent with a kinetic model assuming that the growth rate of adsorbed bacteria on the mineral surface is proportional to the product of the concentration of adsorbed cells and the fraction of adsorption sites unoccupied by cells. In this modeling, the adsorbed cell concentration was related to the free cell concentration in liquid medium through the Langmuir adsorption isotherm. The reactor model for batch operation is used to investigate the effect of solution replacement on bioleaching rate in repeated-batch reactor. Moreover, the batch model is extended to analyze and model the bioleaching in a continuous-flow tank reactor.     

IDENTIFICATION OF PROTEOLYTIC PRODUCTS AS INDICATORS OF QUALITY IN GROUND AND WHOLE MEAT

This study was devoted to the identification of specific peptides and proteins which can serve as indicators of spoilage in meat. Samples of ground and whole meat were subjected to storage at 4C; at intervals of 0, 2, 4, 8, 12 and 16 days, samples were analyzed for pH and microbial populations and subjected to extraction and separation of individual sarcoplasmic and myofibrillar peptides and proteins by SDS (sodium dodecyl sulfate) and native electrophoresis and by RP-HPLC. Sarcoplasmic protein and peptide fractions from RP-HPLC were collected and identified by (electrospray ionization mass spectrometry) ESI-MS. The results demonstrated substantial differences in microbial population and pH between ground and whole meat during storage. Separation by SDS-electrophoresis showed substantial changes in myofibrillar protein of ground meat after 12 days and of whole meat after 16 days of storage. Separation and identification of sarcoplasmic proteins by SDS-electrophoresis and by RP-HPLC followed by ESI-MS revealed the disappearance of a protein fraction band of MW 36 kDa after 8 days of storage in ground and whole meat.     

一种新型运动电线无接触温度测量系统

在生产电线的过程中，一般需要在电线外部包裹一层不导电的聚合物。为了保证电线和绝缘层的质量，在包裹过程中控制连接电线的温度是至关重要的。     

Novel guidelines for the development of pM-selective glass electrodes from oxide glasses

There have been no guidelines for developing pM-selective (M = alkali metal ions) glass membrane electrodes. One of the key points for developing pM-selective glasses is to make glasses not responsive to changes in pH, since pM-measurements can be disturbed by the pH of the solution. As hydrogen-bonded protons in glasses are mobile and their mobility is thought to be responsible for pH-sensitivity, glasses for pM-selective electrodes should contain no hydrogen-bonded protons and no non-bridging oxygen. In this paper, guidelines for developing pH-selective glasses are proposed by using pNa-selective glasses in the Na₂O–Al₂O₃–SiO₂ system as examples. This revised version was published online in November 2006 with corrections to the Cover Date.     

High-Pressure Synthesis of Perovskites Pb(Li1/4Nb3/4)O3 and Pb(Li1/4Ta3/4)O3

Complex perovskite-type compounds with the general formula Pb(B⁺_1/4B⁵⁺_3/4)O₃, where B⁺= Li⁺ and B⁵⁺= Nb⁵⁺ or Ta⁵⁺, were synthesized using a high-pressure technique and studied by X-ray powder diffraction. The X-ray patterns were indexed on the basis of a cubic cell with a ₀= 4.071 Å for Pb(Li_1/4 Nb_3/4)O₃ and a ₀= 4.052 Å for Pb(Li_1/4Ta_3/4)O₃. Electrical properties of the new perovskites were also studied.     

Determination of Antigenicity by Radioimmunoassay and of Trypsin Inhibitory Activities in Heat or Enzyme Denatured Ovomucoid

The effects of heat treatment and enzymic digestion on the antigenic reactivity of ovomucoid were studied. This reactivity was mainly examined by a solid phase competitive radioimmunoassay. The trypsin inhibitory activity was also measured to elucidate its relationship to the antigenic reactivity. The antigenic reactivity and trypsin inhibitory activity diminished in parallel with increase of heating time. However, enzymic digestion caused a more rapid decrease in antigenic reactivity than in trypsin inhibitory activity. From these results, it is suggested that the structure of the antigenic determinants is destroyed in a similar manner to that of the trypsin inhibitory active site when ovomucoid is heated, while the former structure is destroyed more easily than the latter by enzymic digestion.     

Properties of hydrogels synthesized by freezing and thawing aqueous polyvinyl alcohol solutions and their applications

The hydrogel synthesized by freezing a polyvinyl alcohol (PVA) aqueous solution and thawing it slowly has high water content, excellent mechanical properties of high tensile strength, elongation and good shape recovery by elasticity. The PVA used had a degree of polymerization of 2500 and a degree of saponification of 99.5 mol%. The solution was obtained by dissolving 7.5 g of PVA in 80 g of water, this was frozen at –50°C for 3 h and then warmed up to room temperature over 10h. This freezing–thawing process was repeated once again and a hydrogel was synthesized. The hydrogel had a water content of about 90 wt%. Its tensile strength was 0.6 MPa and the elongation at break was 130%. The shape of the hydrogel which was deformed by an external force recovered in a short time when it was released from the force. This recovery had good persistence and repeatability. Applying these properties a strain sensor and a gas pressure sensor were tested. Furthermore, a PVA hydrogel rod containing polyacrylic acid was used as a bending actuator. This hydrogel had the ability to deform when direct current was applied.