• The Korean Journal of Pesticide Science
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• v.4 no.1
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• pp.26-31
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• 2000

An analytical method was approached to determine the residues of benzimidazole fungicides in soybean sprouts and was compared with traditional solvent-based method of extraction, solid phase extraction(SPE) and matrix solid phase dispersion(MSPD). The recoveries of carbendazim for liquid-liquid extraction (LLE), SPE and MSPD in soybean sprouts were $69.25{\sim}79.16$, $79.99{\sim}90.42$ and $92.40{\sim}98.48%$, respectively. The recoveries of thiabendazole for LLE, SPE and MSPD in soybean sprouts were $64.86{\sim}83.26$, $79.12{\sim}94.04$ and $65.44{\sim}73.92%$, respectively. The residues of carbendazim by elapsed time under our cultivated soybean sprouts program found $0.10{\sim}0.25$ mg/kg after 5 days and trace concentration of carbendazim was detected after 7 days. Of the 448 samples analyzed, less than 1.5% had residues of carbendazim ranged from 0.05 to 0.37 mg/kg.

• Korean Journal of Food Science and Technology
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• v.39 no.1
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• pp.71-76
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• 2007

Foodborne illness caused by Noroviruses (NVs) is increasing rapidly in Korea. This study developed an effective detection protocol for NVs found in contaminated oysters and lettuce through an investigation using the major steps of virus particle separation, concentration and RT-PCR. As a surrogate model for NVs, the cultivable feline calicivirus (FCV) that belongs to the same Caliciviridae family was used. Instead of using a time-consuming ultracentrifugation method, efficient methods based on solvent extraction and PEG precipitation procedure were applied. Direct homogenization of a 25g sample of whole oyster and lettuce in 175mL PBS provided the simplicity that would be needed in the actual field of food product examination. The overnight PEG precipitation step at $4^{\circ}C$ was reduced to 3 h by placing the reaction tube in ice and by adjusting the PEG concentrations. The application of the use of chloroform and 0.2 ${\mu}m$ syringe filtration together showed a better detection efficiency than the use of chloroform alone in removing PCR inhibitors for both oyster and lettuce samples. Also, dilution of the extracted RNA solution before PCR provided increased sensitivity. The improved detection protocol developed in this study could be efficiently applied to detect FCV and most likely NVs from oysters and lettuce.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.9
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• pp.1006-1015
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• 2005

We investigated the effect of hydroxyl radicals on the photolysis of triclosan (TCS), which is a potent broad-spectrum antimicrobial agent. TCS degradation during the initial reaction time of 5 min followed a pseudo-first order kinetic model ai all light intensities at a wavelength of 365 nm and at the low light intensities at a wavelength of 254 nm. The photodegradation rate significantly increased with decreasing wavelength and increasing the UV intensities. The activity of hydroxyl radicals was suppressed when methanol was used as the solvent instead of water. An increase in the photon effect was observed when the UV intensity was higher than $5.77{\times}10^{-5}$ einstein $L^{-1}min^{-1}$ at 254 nm, and lower than $1.56{\times}10^{-4}$ einstein $L^{-1}min^{-1}$ at 365 nm. The quantum yield efficiency for the photolysis of TCS was higher at 365 nm than at 254 nm among the above mentioned UV intensities. Dibenzodichloro-p-dioxin (DCDD) and dibenzo-p-dioxin were detected as intermediates at both UV intensities of $1.37{\times}10^{-4}$ and $1.56{\times}10^{-4}$ einstein $L^{-1}min^{-1}$ at 365 nm. Dichlorophenol and phenol were also detected in all cases. Based on our findings, we presented a possible mechanism of TCS photolysis.

• Journal of the Korean Applied Science and Technology
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• v.36 no.4
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• pp.1303-1311
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• 2019

This study was to investigate the antioxidant, anti-inflammatory and neuronal cell protective effects of Poria cocos Wolf and Corni fructus extracted by water and 70% ethanol. Total polyphenol content in water extract of Poria cocos Wolf was significantly higher than those of other extracts. DPPH and ABTS free radical scavenging activity in water extract of Corni fructus was higher than those of other extracts. DPPH and ABTS free radical scavenging activity were increased in a dose-dependent manners. In order to effectively extract total polyphenol contents and anti-oxidant components in Poria cocos Wolf and Corni fructus, hot water extraction method is more efficient than ethanol extraction method. Poria cocos extracts were found to be a superior NO production inhibitory effect compared to Corni fructus extracts. In a neuronal cell viability assay using MPP⁺, the water extract of Poria cocos Wolf protected against MPP⁺-induced neurotoxicity than those of Corni fructus extract. It is considered to be a potential functional material with antioxidant, anti-inflammatory and neuronal protective effect against to oxidative stress according to the extract methods of extracting Poria cocos Wolf and Corni fructus.

• Journal of Korea Technology Innovation Society
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• v.10 no.2
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• pp.183-205
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• 2007

An investigation was undertaken of the optimal discriminant model for predicting the likelihood of insolvency in advance for medium-sized firms based on the technology evaluation. The explanatory variables included in the discriminant model were selected by both factor analysis and discriminant analysis using stepwise selection method. Five explanatory variables were selected in factor analysis in terms of explanatory ratio and communality. Six explanatory variables were selected in stepwise discriminant analysis. The effectiveness of linear discriminant model and logistic discriminant model were assessed by the criteria of the critical probability and correct classification rate. Result showed that both model had similar correct classification rate and the linear discriminant model was preferred to the logistic discriminant model in terms of criteria of the critical probability In case of the linear discriminant model with critical probability of 0.5, the total-group correct classification rate was 70.4% and correct classification rates of insolvent and solvent groups were 73.4% and 69.5% respectively. Correct classification rate is an estimate of the probability that the estimated discriminant function will correctly classify the present sample. However, the actual correct classification rate is an estimate of the probability that the estimated discriminant function will correctly classify a future observation. Unfortunately, the correct classification rate underestimates the actual correct classification rate because the data set used to estimate the discriminant function is also used to evaluate them. The cross-validation method were used to estimate the bias of the correct classification rate. According to the results the estimated bias were 2.9% and the predicted actual correct classification rate was 67.5%. And a threshold value is set to establish an in-doubt category. Results of linear discriminant model can be applied for the technology financing banks to evaluate the possibility of insolvency and give the ranking of the firms applied.

• YAKHAK HOEJI
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• v.48 no.6
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• pp.328-334
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• 2004

Cervical cancer is one of the leading causes of female death. Viral oncoproteins E6 and E7 are selectively retained and expressed in carcinoma cells infected with HPV (Human pa pilloma virus) type 16 and cooperated in immotalization and transformation of primary keratinocyte. E6 and E7 oncoproteins interfere the functions of tumor suppressor proteins p53 and retinoblasoma protein (pRb), respectively. Among a lots of natural products, Mentha arvensis Linne var.piperascens have inhibitory effects on bindings between E6 oncoprotein and tumor suppressor p53, E3 ubiqutin- protein ligase (E6AP). HPV oncoprotein inhibitors from Mentha piperita L. were isolated by solvent partition and column chromatography (Silica gel, RP-18) and inhibitory compounds were finally purified by HPLC using an ELISA screening system based on binding between E6 and E6AP. The aim of this study is to identify the structure of inhibitory compounds and to investigate whether these compounds have inhibitory effects on functions of E6 oncoprotein. We investigated whether caffeic acid methyl ester (CAM) extracted from Mentha piperita L. could inhibit the function of E6 oncoprotein. CAM inhibited the in vitro binding of E6 and E6AP which are essential for the binding and degradation of the tumor suppressor p53 and also inhibited the proliferation of human cervical cancer cell lines (SiHa and CaSKi) in a dose response manner. These results suggest that CAM inhibited the function of E6 oncoprotein, suggesting that it can be used as a potential drug for the treatment of cervical cancers infected with HPV.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.1
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• pp.1-7
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• 2016

Highly porous polymethyl methacrylate (PMMA) microspheres impregnated by $TiO_2$ powder were prepared by spray drying method. The particle size and the porosity were controlled by optimizing the co-solvent ratio and the polymer concentration. $TiO_2$ powder was impregnated into the microspheres upto 74.6 wt% content based on the weight of the resultant $PMMA/TiO_2$ microspheres. SEM images showed that $TiO_2$ powder was well distributed throughout the inside of the microsphere. EDX mapping showed that the Ti signal was well detected from every part of the microspheres, which was the evidence of the formation of the $PMMA/TiO_2$ composite. Hg porosimetry result showed that the porosity was found to be over 50% regardless of the $TiO_2$ contents. The final product was found to have high oil-absorbing capacity and great hiding power, both of which are key properties in designing the microsphere materials for make-up cosmetics application.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.43 no.1
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• pp.35-41
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• 2017

Melanin synthesis inhibition activities were investigated for the extracts prepared from the leaves of Carpinus turczaninowii (C. turczaninowii) by using B16F10 melanoma cells. As a result, the ethanol extract ($100{\mu}g/mL$) showed 72.2% inhibition activities without cell toxicities in MTT assays. For the solvent fractions (n-hexane, ethyl acetate, n-butanol, water), the most potent activities were observed at the ethyl acetate fraction. To isolate the active constituents, the ethyl acetate fraction was further purified to afford four compounds; ethyl gallate (1), quercetin rhamnose (2), kaempferol rhamnose (3) and quercetin galloylrhamnose (4). The identification of the isolates was made by spectroscopic data including NMR spectra, and all of the compounds 1-4 were isolated for the first time from the leaves of C. turczaninowii. Anti-melanogenesis activities were studied for the isolates 1-4, and the compound 4 was determined to decrease the melanin synthesis dose-dependently without causing cell toxicities. ELISA measurement indicated that the isolate 4 decreased the contents of cell tyrosinase, a critical enzyme in melanogenesis. Based on these results, the extracts of C. turczaninowii were found to be applicable as whitening ingredients in cosmetic formulations.

• Membrane Journal
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• v.26 no.4
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• pp.318-327
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• 2016

In this study, alginate/poly(ethylene oxide) (PEO), and chitosan/PEO solution are prepared by dissolving alginate and chitosan into specific solvent for electrospinning. Solutions are poured into 10 mL plastic syringes with a metal nozzle supplied a high voltage power. The solution of alginate and chitosan is controlled by polymer concentration, temperature, relative humidity, applied voltage, distance from nozzle and flow rate of solution. Morphologies of fabricated nanofiber are observed by scanning electron microscopy (SEM). Optimal conditions for electrospinning of alginate nanofiber membrane are 2 wt% of alginate, 2 wt% of PEO at $60^{\circ}C$, 15 cm from the nozzle, $8{\mu}m/min$ flow rate and 20~24 kV. The conditions for elctrospinning of chitosan nanofiber membrane are 2 wt% of chitosan, 2 wt% PEO at $25^{\circ}C$, 15 cm from the nozzle, $8{\mu}m/min$ flow rate and 24 kV. The fabrication conditions of complex nanofiber prepared with chitosan and alginate are 20 cm from the nozzle, $8{\mu}m/min$ flow rate and 26 kV.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.27 no.5
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• pp.235-242
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• 2017

In order to prepare porous scaffolds capable of pore control, PMMA powder serving as a pore-forming agent was added to HA powder to synthesize a slurry containing TBA as a solvent. And then, porous HA scaffolds where pillarshaped pore channels interconnected with each other were fabricated by freeze-casting and sintering. The crystal structure of the HA scaffolds according to the addition amount of PMMA powder was measured by XRD and the surface and inner cross section of the scaffolds were analyzed through SEM. It was found that removal of PMMA during sintering affects the internal structure of the scaffolds and the crystallinity of the HA powder. Furthermore, through evaluating the physical and mechanical properties of the scaffolds, it was confirmed that the porosity, pore size and compressive strength can be controlled by controlling the addition amount of the pore-forming agent. It was also found that the HA scaffolds produced in this study were similar in structure and properties to the natural cancellous bone. This suggests that porous HA scaffolds with PMMA can be used as an alternative to autogenous bone for tissue engineering as an artificial bone scaffold.