Antioxidative, anticoagulant, and α-glucosidase inhibitory effects of 60% (v/v) ethanolic extract from lotus (Nelumbo nucifera) leaves were investigated in vitro. The yield and polyphenol content of the lotus leaves extract were 35.3±1.1% and 186.2±5.2 μg gallic acid equivalents/mg, respectively. The lotus leaves extract effectively scavenged free and cation radicals, and nitrite in a concentration-dependent manner, and possessed potent reducing power. The lotus leaves extract had remarkable anticoagulant and α-glucosidase inhibitory activities as a function of the extract concentration.

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The purpose of this study was to examine changes in the most comfortable level (MCL) and the uncomfortable level (UCL) depending on hearing threshold level (HTL) by investigating loudness growth among persons with normal hearing (NH) and sensorineural hearing loss (SNHL) at 500 Hz and 3,000 Hz. Based on the results, this study intended to provide useful data to calculate gain or frequency response curve and SSPL90 or OSPL90 of hearing aid that was used by Koreans with hearing loss. The NH group consisted of 17 persons (17 ears) in total who had the pure tone threshold average of 20 dB HL or less and who were 23-33 years old (average: 27.9 years, SD: 4.0 years). The SNHL group consisted of 117 persons (161 ears) in total who had the HTL of 40-75 dB HL at 500 Hz or 3,000 Hz and who were 19-78 years old (average: 55.1 years, SD: 15.4 years). As for presented tone, 5% frequency-modulated tone was used at 500 Hz and 3,000 Hz. Based on the results of study by Allen (1990), loudness category (LC) for loudness growth test was divided to 7 LCs before the HTL of 40-75 dB for NH and SNHL was divided by 5 dB interval at 500 Hz and 3,000 Hz. The results of this study were as follows. First, at 500 Hz and 3,000 Hz, the MCL of NH was 51.5 and 56.8 dB HL while the UCL was 88.5 dB HL and 88.7 dB HL. Consequently, the MCL at 3,000 Hz was found to be higher by 5.3 dB (p < .05). Second, the MCL and the UCL of SNHL persons increased as a function of the HTL. However, slope of regression equation was low in the order of the HTL, the MCL and the UCL. Therefore, it was confirmed that dynamic range became narrow according to increase in the HTL. Third, the MCL showed the higher correlation with the HTL than the UCL. This study was meaningful in that the study intended to measure loudness growth of Koreans with NH and SNHL. The results of this study are expected to have influences on development of hearing aid fitting formula for Koreans with hearing loss.

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We consider the problem to find economic inventory quantity of a single commodity under stochastic demands and order cancellation. In contrast to the traditional economic production quantity (EPQ) model, we assume that once the amount of inventory reaches to a predetermined level of quantity then the production is not halted but its production speed decreases until the inventory level drops to zero. We establish two probabilistic models representing the behaviors of both the high-production period and low-production period, respectively, and derive the relationship between the level of inventory and costs of production, cancellation, and holding, from which the quantity of economic inventory is obtained. †