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51.
The properties of a cermet solid body containing 34% Al2O3 and 66% 80Cr–20Mo alloy (50Al2O3-50 alloy by volume) are given as firing shrinkage, density, modulus of rupture, tensile strength, stress-rupture life, modulus of elasticity, oxidation resistance, thermal-shock resistance, and thermal expansion. It is shown that substitutions of the 80Cr-20Mo alloy for Cr in a similar cermet developed earlier substantially improved thermal-shock resistance.  相似文献   
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Wine yeast, in common with other industrial Saccharomyces cerevisiae yeast, can produce hydrogen sulfide during alcoholic fermentation. The aim of this work was to evaluate a genetic strategy for reducing hydrogen sulfide production by lowering the activity of NADPH-dependent sulfite reductase, a key enzyme in the biosynthesis of the sulfur-containing amino acids. The role of amino acids predicted to be necessary for cofactor binding was investigated by comparisons with other proteins in the ferredoxin family. Substitutions in the glycine-rich loop domain (glycines 891 and 893) and at serine 953 of the alpha subunit, Met10p, appear to strongly affect NADPH binding. However, mutations in two amino acids that are completely conserved within the NADPH binding domain of the ferredoxin reductase family, lysine 959 and cysteine 987, have minimal effect on enzyme activity. Serine 820 is indicated to be essential for efficient FAD binding. The two-hybrid system was used to confirm that Met 1 0p interacts with Met5p, the predicted beta subunit of sulfite reductase. Binding of the subunits could only be demonstrated in the absence of methionine, indicating that an additional factor, possibly siroheme, is required to mediate this interaction. Strategies to decrease, but not eliminate, sulfite reductase activity in the cell using identified mutants were tested, and the findings are discussed with the a view to producing improved wine strains.  相似文献   
54.
The milk fat globule membrane (MFGM) surrounds fat globules, protects them against lipolysis and disperses the milk fat in the milk plasma. Besides their structural and emulsifying roles, in vivo and in vitro studies have demonstrated that phospholipids and sphingolipids of MFGM possess cancer risk‐reducing properties. Several reports attribute its chemopreventive activity to products of sphingomyelin hydrolysis, which affect multiple cellular targets that control cell growth, differentiation and apoptosis. With knowledge on the potential health benefits of MFGM lipids and proteins, dairy industries could in the future address their research in developing new functional dairy products enriched in beneficial MFGM components.  相似文献   
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Porous glasses produced by phase separation and leaching are used as substrates for the exchange of metal cations from a basic solution for the protons of silicon-bonded hydroxyl ions on the pore surfaces and on residual silica gel present in the pores. This method yields extremely homogeneous, fully dense high-silica glasses with low to moderate concentrations of metal dopants after sintering to collapse the pores. The quantity and rate of ion exchange are studied as a function of time, solution pH, and solution ion concentration for various dopant salts. In addition, a double ion-exchange method is described whereby, during the second exchange, ions which have a relatively low solubility in basic solutions can be exchanged from a neutral or acidic solution onto the glass surface.  相似文献   
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The protein content, baking characteristics, physical characteristics, and sensory characteristics of gingerbread cookies supplemented with sunflower protein concentrate were examined. Protein content increased from 7.2% to 15.9% as the substitution level increased from 0% to 30%. Supplementation resulted in higher moisture loss during baking and more compact inner structure of the cookies. Although the texture of supplemented cookies was slightly crispier and harder, evaluation showed that sensory characteristics were not significantly affected by the addition of sunflower protein concentrate.  相似文献   
57.
This study explores the impacts of publicly and privately funded housing rehabilitation efforts in Cleveland, Ohio. The results show that (1) selective census tracts receiving publicly funded home owner rehabilitation assistance did not experience demographic, economic or property stabilization; (2) private borrowing for housing renovation increases as the number of home owners, median gross rents, median family incomes, median values of owner-occupied housing and median sales-to-median assessed market ratios increase and (3) heterogeneous populations, poverty incomes, high unit vacancies, high tax delinquencies and housing demolitions decrease home owner propensities to borrow for repairs and maintenance. Many neighborhoods have experienced incumbent upgrading, but housing disinvestment and property tax delinquency threatens neighborhood stability. Public intercession is unlikely to influence these real estate market processes because housing disinvestment is merely symptomatic of a deeper economic malaise. Only a dramatic economic upturn can possibly slow housing disinvestment. Otherwise, housing unit removal shall continue unabated, inevitably wrecking neighborhoods and frustrating public efforts.  相似文献   
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Whole‐wheat muffins and batter were prepared with 0–5% flaxseed meal or by direct substitution of vegetable oil with flaxseed oil, and were evaluated for physicochemical properties. The storage properties of muffins were evaluated over 5 days at 0.44 relative vapor pressure (RVP) and ambient temperature. Batter viscosity increased from 2730 ± 530 to 12,775 ± 4425 cps with increasing flaxseed meal content while other properties were unaffected. When flaxseed meal was added at 5%, the maximum force for compression of freshly baked muffins increased from 369.6 ± 3.0 to 594.6 ± 10.2 g while the internal elasticity decreased from 60.2 ± 0.5 to 55.4 ± 1.6. Freshly baked muffins with flaxseed meal had lower color scores, L, and a values than control muffins. The storage stability of muffins was unaffected by the addition of flaxseed meal. Flaxseed meal or oil can be used in muffins to enhance the nutritional value without detrimentally changing the freshness or storage properties.  相似文献   
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SUMMARY— Guava puree concentrate, containing 1000 ppm potassium sorbate, showed no gross signs of spoilage during storage for 5 months at 45°F. During this period, the initial number of yeasts (the predominant spoilage organisms) decreased steadily to an insignificant level. Flavor and aroma quality were good and did not deteriorate appreciably until the fourth month of storage. Browning of the concentrate was apparent after 2 months and became more pronounced with continued storage. The browning may be related to a rapid loss of ascorbic acid that was virtually complete after 1 month. The carotenoid level, on the other hand, remained constant during the 5-month storage period.  相似文献   
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