• Applied Biological Chemistry
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• v.41 no.4
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• pp.246-250
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• 1998

The cytotoxic activity of methanol extracts of 25 leguminous seeds in vitro was evaluated by sulforhodamine B assay, using the five human solid A549 lung, SK-OV-2 ovarian, SK-MEL-2 melanoma, XF-498 CNS and HCT-15 colon tumor cell lines. The responses varied with both cell line arid leguminous seed used. Extracts of Canavalia lineata and Glycine soja revealed potent cytotoxic activity against A549 arid SK-MEL-2 cell lines. Moderate activity was observed in the extracts of Cassia obtusifolia and Glyeine max var. chungtae, and C. lineata and Vigna angulasis against SK-MEL-2 and HCT-15 cell lines, respectively. The other seed extracts were ineffective against model tumor cell lines. Because of their potent cytotoxic activities, the activity of each solvent fraction from C. lineata and G. soja was determined and the potent activity was produced from their chloroform fractions. As a naturally occurring therapeutic agent, leguminous seeds described could be useful for developing new types of anti-tumor agents.

• Phonetics and Speech Sciences
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• v.7 no.4
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• pp.27-33
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• 2015

This paper proposes an audio event classification method using Deep Neural Networks (DNN). The proposed method applies Feed Forward Neural Network (FFNN) to generate event probabilities of ten audio events (dog barks, engine idling, and so on) for each frame. For each frame, mel scale filter bank features of its consecutive frames are used as the input vector of the FFNN. These event probabilities are accumulated for the events and the classification result is determined as the event with the highest accumulated probability. For the same dataset, the best accuracy of previous studies was reported as about 70% when the Support Vector Machine (SVM) was applied. The best accuracy of the proposed method achieves as 79.23% for the UrbanSound8K dataset when 80 mel scale filter bank features each from 7 consecutive frames (in total 560) were implemented as the input vector for the FFNN with two hidden layers and 2,000 neurons per hidden layer. In this configuration, the rectified linear unit was suggested as its activation function.

• Toxicological Research
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• v.19 no.1
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• pp.45-50
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• 2003

The purpose of this study was to determine the role of substituted groups in phenolic compounds to develop an anticancer agent having strong cytotoxicity against cancer cells but weak against normal cells. The phenolic compounds used in this study were gallic acid and ferulic acid with hydroxyl and carboxyl groups, syringic acid with hydroxyl, carboxyl and methoxy groups, and pyre-gallol with hydroxyl groups. Cytotoxicities of these compounds were evaluated by MTT assay for cell viability and XTT assay for cell adhesion activity in normal human skin fibroblast (Detroit 551) and human skin melanoma (SK-MEL-3) cells. Syringic acid, gallic acid and ferulic acid decreased the cell viability and cell adhesion activity in SK-MEL-3 cells but not in Detroit 551 cells while pyrogallol decreased in both cells. The susceptibility of cell viability based on the $IC_{50}$ values of MTT assay in Detroit 551 cells was in the following order: pyrogallol > gallic acid > ferulic acid > syringic acid, while it was in SK-MEL-3 cells: Syringic acid > progallol > ferulic acid > gallic acid. These results suggest that carboxyl and methoxy groups of these compounds play an important role in selectivity of cytotoxicity in normal and cancer cells.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.1
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• pp.86-91
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• 2012

To provide high voice quality of real-time voice communication based on telematics exposed to various noise environments, the noise reduction algorithm with low computing load is required to effectively remove the noise. In this paper, we propose a noise reduction algorithm based on Mel-Filter and illustrate the proposed algorithm comparing with conventional noise reduction algorithms. As a experimental result that evaluates the performance of the noise reduction algorithms under the car and babble noise environments, the proposed noise reduction algorithm has the lower computing load with the similar PESQ score compared to the conventional noise reduction algorithms. It proves that the proposed noise reduction algorithm can efficiently remove the noise in mobile telematics.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.20 no.3
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• pp.14-28
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• 2007

Objective : Hwagi-Jokyeong-Tang (化氣調經湯, HJT) was described in DongeuiBogam(東醫寶鑑). This remedy has been used to treat patients with Naryeok, which is similar as tuberculous cervical lymphadenitis in western medicine. Methods : In this study, the present author investigated the effects of HJT on on Human HaCaT keratinocyte and malignant melanoma cells such as SK-MEL-2 and B16F10 in terms of cell viabilities, proliferations, DPPH free radical scavenging activities, oxygen free radical productions and inhibitory action on elastase activities. Results : HJT acceleated proliferation of HaCaT keratinocytes dose-dependantly. HJT also prevented cell death of HaCaT induced by Hydrogen peroxide, which products oxygen free radicals. On the contrary, HJT did not affect proliferations of SK-MEL-2 or B16F10. In addition, HJT was shown to have DPPH free radical scavenging activities and also have inhibitory effects on elastase activities too. On the fluorescent examinations, the present author know that HJT did not affect production levels of oxygen free radicals in malignant melanoma cell, SK-MEL-2. Conclusions : These results suggest that HJT has possibilities of usage for functional cosmetics which have skin regeneration or prevention from skin tissue injury.

• The Journal of the Acoustical Society of Korea
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• v.13 no.1E
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• pp.71-81
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• 1994

In this paper, we propose a pseudo-cepstral representation of line spectrum pair(LSP) frequencies and evaluate speech recognition performance with cepstral lift using the pseudo-cepstrum. The pseudo-cepstrum corresponding to LSP frequencies is derived by approxmating the relationship between LPC-cepstrum and LSP frequencies. Three cepstral liftering procedures are applied to the pseudo-cepstrum to improve the performance of speech recognition. They are the root-power-sums ligter, the general exponential lifter, and the bandpass lifter. Then, the liftered psedudo-cepstra are warped into a mel-frequency scale to obtain feature vectors for speech recognition. Among the three lifters, the general exponential lifter results in the best performance on speech recognition. When we use the proposed pseudo-cepstra feature vectors for recognizing noisy speech, the signal-to-noise ratio (SNR) improvement of about 5~10dB LSP is obtained.

• Biomolecules & Therapeutics
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• v.9 no.4
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• pp.249-257
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• 2001

The effect of oxidative stress on the alterations of different antioxidant enzyme activities was investigated in human skin melanoma cell line (SK-MEL-2). Oxidative stress was induced by the exposure to hydrogen peroxide ($H_2O$$_2$). SK-MEL-2 cells were treated with antioxidants such as vitamin E and selenomethionine in combination with $H_2O$$_2$. SK-MEL-$_2$ cells were exposed to various concentrations of $H_2O$$_2$ and measured the time course of changes in cell viability and antioxidant enzyme activities for 24 hr. Oxidative stress was induced by the exposure to 2.5mM hydrogen peroxide ($H_2O$$_2$) resulted in declining significantly for 24 hr. GPX and CAT activities peaked at 3 hr and returned to control levels by 24 hr. On the contrary, SOD activity was inactive before 6 hr but recovered at 24 hr. In case vitamin E (Vit E) and selenomethionine (Se-Met) were used at nontoxic concentrations (25$\mu$M Vit E/500$\mu$M Se-Met) to oxidative stress was induced by the exposure to hydrogen peroxide ($H_2O$$_2$) led to a 3- and 5-fold increase on the viability comparing to control and caused an increase in GPX activity respectively.

• The Korean Journal of Physiology and Pharmacology
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• v.2 no.4
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• pp.411-417
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• 1998

The role of phospholipase ($A_2\;PLA_2$) in tumor cell growth was investigated using SK-N-MC human neuroblastoma cells. 4-Bromophenacyl bromide (BPB) and mepacrine (Mep), known $PLA_2$ inhibitors, suppressed growth of the tumor cells in a dose-dependent manner without a significant cytotoxicity. Melittin (Mel), a $PLA_2$ activator, enhanced the cell growth in a concentration-dependent fashion. The growth-enhancing effects of Mel were significantly reversed by the co-treatment with $PLA_2$ inhibitors. In addition, Mel induced intracellular $Ca^{2+}$ release from internal stores like as did serum, a known intracellular $Ca^{2+}$ agonist in the tumor cells. Intracellular $Ca^{2+}$ release induced by these agonists was significantly blocked by $PLA_2$ inhibitors at growth-inhibitory concentrations. Arachidonic acid (AA), a product of the $PLA_2-catalyzed$ reaction, induced cell growth enhancement and intracellular $Ca^{2+}$ release. These effects of AA were significantly blocked by BAPTA/AM, an intracellular $Ca^{2+}$ chelator. Taken together, these results suggest that the modulation of $PLA_2$ activity may be one of the regulatory mechanisms of cell growth in human neuroblastoma cells. Intracellular $Ca^{2+}$ may act as a key mediator in the $PLA_2-induced$ growth regulation.

• Carbon letters
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• v.9 no.3
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• pp.200-202
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• 2008

In order to improve the thermal stability of PAN-based electrospun fibers, AP-PER-MEL and $TiO_2$ were added in to the fibers as additives. The polymer composite with uniformly mixed additional agents was obtained. In case of non-treated sample, the fibers were burn off completely with high rate within $620^{\circ}C$. But in case of treated samples (EF-M and EF-MT), it is sure that the thermal stability was improved by studying TGA data and ISO flammability test about 20 and 30%, respectively. A synergy effect of adding two kinds of agents (AP-PER-MEL and $TiO_2$) into PAN-based electrospun fibers was confirmed. Through SEM images, it is confirmed that the fiber shape can be kept even after addition of agents (AP-PER-MEL and $TiO_2$). Finally the thermal stability of fibers was largely developed with keeping the nature of PAN-based fibers effectively.

• Journal of Microbiology and Biotechnology
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• v.29 no.8
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• pp.1204-1211
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• 2019

Fungal exopolysaccharides are important natural products having diverse biological functions. In this study, exopolysaccharides from Fomitopsis castanea mycelia (FEPS) were prepared, and the highest mushroom tyrosinase inhibitory activity was found. FEPS were prepared from cultivation broth by ethanol precipitation method. The extraction yield and protein concentration of FEPS were 213.1 mg/l and 0.03%, respectively. FEPS inhibited mushroom tyrosinase with the half maximal inhibitory concentration ($IC_{50}$) of 16.5 mg/ml and dose-dependently inhibited cellular tyrosinase activity (63.9% at $50{\mu}g/ml$, and 83.3% at $100{\mu}g/ml$) in the cell-free extract of SK-MEL-5 human melanoma cell and ${\alpha}$-melanocyte-stimulating hormone (${\alpha}-MSH$)-stimulated melanin formation in intact SK-MEL-5 human melanoma cell. The $IC_{50}$ of FEPS against NO production from RAW264.7 macrophage cells was $42.8{\pm}0.64{\mu}g/ml$. By in vivo study using a zebrafish model, exposure of FEPS at $400{\mu}g/ml$ to dechorionated zebrafish embryos for 18 h decreased the pigment density, compared to that without FEPS-treated control.