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41.
Susana Criado Norman A. García Maria I. Gutirrez Vicente Avila Sonia G. Bertolotti Rio Cuarto 《European Journal of Lipid Science and Technology》1996,98(5):172-175
The ability of mono-, di-, tri-and tetra-hydroxyflavones (7-and 3-hy-droxyflavones, 7, 8-dihydroxyflavone, baicalein and fisetin) to act as photoprotectors against singlet molecular oxygen [O2(Δg)]-initiated photooxidation of fats has been established by a kinetic study. The overall quenching rate constants for a series of five hydroxyflavones perfectly parallel their respective behaviour as inhibitors of the sensitized photooxidation of linoleic acid. The best antioxidative effect was exerted by 7-hydroxyflavone which does not chemically react with O2(1Δg). Nevertheless for the remaining flavonoids of the series, the physical deactivation of O2(1Δg) largely prevails over the chemical process. As for the cases of phenols and related hydroxy-aromatic derivatives, the ionization of the -OH group in the flavones, dramatically accelerates the rate of photooxidation. Under these conditions, the 7-hydroxyflavone also reacts effectively with O2(1Δg). Given that flavonoids are natural oil components, this medium effect should be taken into account during the oil-refining process, in order to avoid the flavonoid photodestruction. 相似文献
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The effects of cooking temperature, time and temperature of brine-salting, and temperature of ripening on the behavior of Enterobacteriaceae in Manchego cheese were studied. Fifty lots of cheese from raw ewe's milk manufactured and ripened under different conditions were investigated throughout a 60-day ripening period. Differences in pH values due to temperature-dependent whey retention accounted for the effect of cooking temperature on coliform and fecal coliform counts. Temperature of brine-salting had no effect on Enterobacteriaceae counts, but a significant effect of salting time on Enterobacteriaceae and fecal coliform counts was detected. Ripening temperature was the manufacturing variable with greatest influence (P<.01) on Enterobacteriaceae and coliform counts during the whole curing period. 相似文献
47.
P Sánchez García 《Canadian Metallurgical Quarterly》1997,114(1):157-63; discussion 164-7
48.
The first Brazilian uranium mine and mill are located on the Poços de Caldas plateau, in the Central State of Minas Gerais. The pre-operational environmental survey was carried out over a period of two years by the Brazilian Nuclear Energy Commission (CNEN), through the Instituto de Radioproteção e Dosimetria (IRD). The selection of the materials to be monitored, the sampling points and the radionuclides to be analysed were based on critical parameters taking into account the meteorological and hydrological characteristics of the site as well as land use. The results obtained are sufficient to characterize the environmental background of the area, and will allow an assessment of the environmental impact due to the operation of the facility and an evaluation of the adequacy of the effluent emmission control measures. In relation to their contribution to the population dose, the results indicated that 226Ra and 210Pb will be the important radionuclides. 相似文献
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We describe a patient with aspergillosis of the maxillary antrum, and systemic affectation (anemia, anorexia, fever). Through a Caldwell-Luck approach, the maxillary antrum was opened and an irregular mass removed, postoperatively the patient has done well, disappearing in two months the ORL and systemic symptoms. 相似文献
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