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ABSTRACT: Spores of Penicilliumexpansum are the most important airborne component of fungal contamination and are commonly present in the moist air in cold storage rooms where fruits and vegetables are stored. To improve the ability of activated carbon felt-supported titanium dioxide (TiO2/ACF) to remove spores of P. expansum from the atmosphere, measurements for the removal efficiency of the spores at a temperature of 3 degrees C+/-1 degrees C and relative humidity of 90%+/-3% had been made on photocatalytically-activated (PC) silver-doped TiO2/ACF prepared by ion sputtering in two different modes and photoelectrocatalytically-activated (PEC) TiO2/ACF films. The Weibull distribution model was used to define the degree of microbial inactivation attributable to the PC or PEC films. The key parameters of the PC or PEC affecting the disinfection efficiency in terms of the reliable life (t(R) value) of this model were studied. Both silver-doped TiO2/ACF and PEC on TiO2/ACF improved destruction of this airborne microbe. Silver deposited on the surface of the prepared ACF-supported TiO2 films (Ag/Ti=0.012, atomic ratios) dramatically reduced t(R) value. With respect to the PEC, a model was established using response surface methodology to describe the relationship between the t(R) value and the key affecting parameters, including light intensity and bias voltage. The optimized parameters were found to be a light intensity of 2.3 mW x cm(-2) with a bias voltage of 66.7 V.
International journal of food microbiology 10/2009; 136(3):332-9. · 3.01 Impact Factor
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ABSTRACT: Previous data demonstrated that hydroxysafflor yellow A (HSYA), a yellow color pigments extracted from the safflower, was an effective agent against focal cerebral ischemia. In the present study we demonstrated that HSYA prevented the injury in cultured cerebral cortical neurons induced by oxygen-glucose deprivation and increased the cell viability, as shown by the inhibition of both LDH and NO efflux. Further, HSYA administered orally 3 d before middle cerebral artery occlusion has the capacity to reduce cerebral infarct size and edema after 2 h cerebral ischemia followed by 24 h reperfusion in rats, and to significantly improve neurological behavior scores. Mean while, treatment with HSYA significantly decreased both mRNA and protein levels of IL-1beta, TNF-alpha in ischemic brain tissue. These results suggested that the protection of HSYA results from, at least in part, suppression of inflammatory responses following focal ischemia reperfusion.
Archives of Pharmacal Research 09/2008; 31(8):1010-5. · 1.59 Impact Factor
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ABSTRACT: The processing parameters for ultrasound and 60Co-γ irradiation were optimized for their ability to inactivate Lactobacillus sporogenes in tomato paste using a systematic experimental design based on response surface methodology. Ultrasonic power, ultrasonic processing time and irradiation dose were explored and a central composite rotation design was adopted as the experimental plan, and a least-squares regression model was obtained. The significant influential factors for the inactivation rate of L. sporogenes were obtained from the quadratic model and the t-test analyses for each process parameter. Confirmation of the experimental results indicated that the proposed model was reasonably accurate and could be used to describe the efficacy of the treatments for inactivating L. sporogenes within the limits of the factors studied. The optimized processing parameters were found to be an ultrasonic power of 120 W with a processing time of 25 min and an irradiation dose of 6.5 kGy. These were measured under the constraints of parameter limitation, based on the Monte Carlo searching method and the quadratic model of the response surface methodology, including the a/b value of the Hunter color scale of tomato paste. Nevertheless, the ultrasound treatment prior to irradiation for the inactivation of L. sporogenes in tomato paste was unsuitable for reducing the irradiation dose.
Radiation Physics and Chemistry. 78(3):227-233.
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ABSTRACT: Postharvest loss of quality is an important problem in the food and horticultural product industry. One of the major factors contributing to loss of quality is the uncontrolled exposure of the products to small amounts of ethylene gas during storage. In this study we investigated the photoelectrocatalytic (PEC) degradation of ethylene gas at a temperature of 3 ± 1 °C and relative humidity of 90 ± 3% on an activated carbon felts (ACF)-supported photocatalyst titanium dioxide photoelectrode [TiO2/ACF] or on a photoelectrode which had been modified by coating the ACF support with platinum [TiO2/ACF-Pt]. The apparent pseudo-first-order kinetic model was used to describe the PEC degradation of ethylene. The key designing parameters for a PEC reactor affecting the degradation efficiency in terms of the rate constant of this model were studied, including the bias voltage and the light intensity. Degradation of ethylene by applying a bias voltage to the [TiO2/ACF] |Nafion|[TiO2/ACF] electrode-membrane assembly or to the [TiO2/ACF-Pt] |Nafion|[TiO2/ACF-Pt] electrode-membrane assembly enhanced the efficiency of photocatalytic (PC) degradation. The combination of the ACF support modified with platinum and the applied bias voltage were found to have an additive enhancement effect on the rate constant compared to PEC degradation carried out using the unmodified ACF support. With respect to the [TiO2/ACF-Pt] |Nafion|[TiO2/ACF-Pt] electrode-membrane assembly, a kinetic model was established using response surface methodology to describe the relationship between the rate constant and the affecting parameters. Optimized parameters were found to be a light intensity of 3.1 mW cm−2 with a bias voltage of 47.5 V.
Journal of Photochemistry and Photobiology A: Chemistry. 208(1):27-35.
