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31.
32.
The lipolytic and proteolytic activity of Penicillium camemberti PC TT033 and Penicillium roqueforti PR G3, cultured on the whey solids or simulated cheese media, were compared under several pH reaction conditions. Lipolytic activity was higher when both strains had been cultured on the whey medium than on the simulated cheese medium, whereas proteolytic activity was less influenced by the culture medium. The relationship between the reaction pH and these enzyme activities was dependent on the culture medium, which suggested that the expression level and balance of isozyme rely on the culture substrate.  相似文献   
33.
There are many dried foods of hollow cylinder-shapes in the market. Hygrostress cracks form in these foods during drying without a careful process control. The objective of the present work was to develop a simulation method for heat and moisture transfer in hollow cylinder-food coupled with hygrophysical changes. A modified Luikov's model was used for the development together with a virtual work minimization principle, critical tensile stress criterion for crack formation, and critical crack-tip-opening angle criterion for crack propagation. The developed, computerized simulation model was validated through drying experiments of samples made from a starch hydrate.  相似文献   
34.
The gelation of myosin has a very important role in meat products. We have already shown that myosin in low ionic strength solution containing l ‐histidine forms a transparent gel after heating. To clarify the mechanism of this unique gelation, we investigated the changes in the nature of myosin subfragments during heating in solutions with low and high ionic strengths with and without l ‐histidine. The hydrophobicity of myosin and heavy meromyosin (HMM) in low ionic strength solution containing l ‐histidine was lower than in high ionic strength solution. The SH contents of myosin and HMM in low ionic strength solution containing l ‐histidine did not change during the heating process, whereas in high ionic strength solution they decreased slightly. The heat‐induced globular masses of HMM in low ionic strength solution containing l ‐histidine were smaller than those in high ionic strength solution. These findings suggested that the polymerization of HMM molecules by heating was suppressed in low ionic strength solution containing l ‐histidine, resulting in formation of the unique gel.  相似文献   
35.
Vaccination with peptides that induce a specific immune response is a potential prophylactic or therapeutic strategy against viral infections and tumors. Because of the extensive polymorphism of the HLA loci, synthetic peptide vaccines must consist of a cocktail of peptides that bind specifically to different HLA molecules. Such cocktails should be optimized for the target population as each population has its specific HLA gene frequencies. To achieve maximum population coverage with a minimum number of peptides, information is needed on the ranking of the most frequent HLA phenotypes. We introduce the minimal phenotype panel, which is the smallest combination of HLA antigens selected so that the proportion of individuals in a population that express at least one of the antigens in the panel exceeds a desired minimum value. We developed a method for assembling minimal phenotype panels based on known HLA class I gene frequencies. We give an example based on a set of 2446 well-defined HLA-typed, random, healthy, unrelated, Dutch Caucasoid individuals. In addition, we discuss the possibility of assembling minimal phenotype panels based on two-locus haplotypes, which enables the assembly of phenotype panels from the antigens of both loci.  相似文献   
36.
We evaluated portal and peripheral blood immunoreactive insulin concentrations (IRI) after glucose infusion in patients undergoing gastrectomy. Seventy-four patients were divided into following two groups: 68 received 25g glucose infusion in an hour (glucose group), and the remainder received no glucose (control group). Portal blood IRI level in glucose group was about thirty-fold higher than that in control group. However, peripheral blood IRI did not correlate with portal blood IRI in glucose group. In addition, significant negative correlation between portal blood IRI and blood glucose was observed in glucose group. Our results reveal that adequate pancreatic insulin secretion occurs after glucose infusion during gastrectomy, but peripheral blood IRI does not reflect this pancreatic insulin secretion. The results also suggest that blood glucose may be regulated by the liver under these conditions.  相似文献   
37.
Comprehensive analyses of mitochondrial (mt)DNA of a recipient of heart transplantation at age 7 because of severe cardiomyopathy revealed three germ line point mutations, each one in the 12S rRNA gene, in the CO1 gene and in the cytochrome b gene, respectively. As the somatic mutation, extensive fragmentation of mtDNA associated with 212 kinds of deletions was detected in contrast to 5 kinds in an age-matched negative control. A recipient's positive control having almost the same base-substitutions and mutations with the recipient except one in the CO1 gene also developed severe cardiomyopathy died at age 20. The close relation between phenotype and mtDNA genotype provides the basis of our understanding of cell death and premature ageing.  相似文献   
38.
39.
Diesel exhaust particulates were extracted with benzene-ethanol (3:1, v/v) and separated into five fractions by silica-gel column chromatography. Direct-acting mutagenic activity was assayed by the Ames test using the Salmonella typhimurium YG1024 strain. The total activity of five fractions was about four times greater than that of the crude extract, suggesting that the activities in the fractions were suppressed in the crude extract. Strong activity was observed in fraction 4 which was eluted with dichloromethane (61.5% of the total activity) and fraction 5 which was eluted with ethanol (35.3%). Nitropolycyclic aromatic hydrocarbons (NPAHs) were determined by high-performance liquid chromatography with chemiluminescence detection. They were found mainly in fraction 4, although one NPAH was in fraction 3 which was eluted with n-hexane-dichloromethane (3:1, v/v). Based on these results, 53.1% of the activity in fraction 4 was attributed to NPAHs. The contribution of 1-nitropyrene and 1,3-, 1,6- and 1,8-dinitropyrenes was great and that of the other NPAHs was small. The mutagenic compound in fraction 5 was not identified. Fractions 1 and 2, which were eluted with n-hexane, and fraction 3 suppressed the activity of fraction 4. Polycyclic aromatic hydrocarbons in fractions 2 and 3 were considered as possible suppressors of NPAHs.  相似文献   
40.
Friction coefficients in cold forging: A global perspective   总被引:1,自引:0,他引:1  
Worldwide, at least twenty different tribological tests have been proposed for the empirical determination of friction coefficients in cold forging processes. Due to the varying test setups, means of measurement, and level of abstraction, the comparability of the outcomes is, however, disputable. Within this work, six established test principles are compared using identical tribological systems. Large differences between the empirically determined friction coefficients are observed but can be explained under consideration of the respective tribological loads. Additional investigations of an extrusion process reveal that friction models also have to take into account the varying local thickness of the lubricant film.  相似文献   
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