• The Korean Journal of Food And Nutrition
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• v.12 no.6
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• pp.564-568
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• 1999

Habituation to alkali condition and susceptibility to antimicrobial agents were investigated to determine methods t inactivation Escherichia coli O157:H7 associated with food poisoning. The investigation showed that Escherichia coli O157:H7growth at pH 9.0 The susceptibilities of Escherichia coli O157:H7 to 13 drugs examined were found highest in regad to saicin and ceftriaxone and lowest in regard to erythromycin and josamycin. No significant changes in minimal inhibitory concen-tration(MIC) values of bactericidal effect was found when saicin and ceftriaxone were irradiated with doses of 5-100KGy.

• Journal of Korean Ophthalmic Optics Society
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• v.9 no.2
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• pp.381-389
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• 2004

To investigate changes of multi-purpose solutions for soft contact lens(MPS) depending on using period or keeping temperature, we evaluate four brands of MPS. No significant difference was seen in protein deposit removing efficacy after samples had used for 24 weeks and kept at $4^{\circ}C$, $20^{\circ}C$ or $30^{\circ}C$. The pH values of the samples of 4 brands measured weekly over the 24 week testing period. The initial average pH value of samples were 7.0, 7.5, 7.6 or 8.2. One brand of MPS was in the range of the threshold for ocular awareness, which is outside the zone of 6.6 ~ 7.8. During the testing period, the pH value were decreased in using period-dependent manner. At the 24th week, the average pH values of samples turned to 6.6, 7.2, 7.2 or 7.7. However, the difference of keeping temperature was not associated with decreased levels of pH values. After 24 weeks, one of total 36 samples was contaminated by bacteria. Furthermore, the change of components was shown after 24 weeks in the analysis using thin layer chromatography and the analysis of UV absorption pattern. The results of our study provides that the keeping temperature of MPS is not the important factor of changes of MPS, but the using period of MPS can cause contact lens wearers discomfort.

• The Korea Journal of Herbology
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• v.38 no.6
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• pp.45-52
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• 2023

Objectives : Effects of baicalein (BA) on oxidative stress in RAW 264.7 mouse macrophages stimulated with peptidoglycan (PG) and lipopolysaccharide (LPS) were investigated. Methods : RAW 264.7 co-stimulated with LPS and PG were incubated with BA at concentrations of 25 and 50 µM. Incubation time was 18 h, 20 h, 22 h, 24 h, and 26 h. After incubation, the production of hydrogen peroxide in RAW 264.7 was measured with dihydrorhodamine 123 assay. Additionally, RAW 264.7 stimulated with PG were incubated with BA at concentrations of 25 and 50 µM for 24 h. After incubation, NO production was evaluated by griess reagent assay. Results : BA significantly inhibited hydrogen peroxide productions (p <0.05). In details, production of hydrogen peroxide in 'LPS and PG'-stimulated RAW 264.7 treated for 18 h with BA at concentrations of 25 and 50 µM was 91.27% and 89.22% of the control group treated with LPS and PG only, respectively; the production of hydrogen peroxide for 20 h was 92.19% and 90.58%, respectively; production of hydrogen peroxide for 22 h was 91.69% and 89.89%, respectively; production of hydrogen peroxide for 24 h was 92.4% and 90.19%, respectively; production of hydrogen peroxide for 26 h was 91.7% and 89.04%, respectively. Additionally, BA at the concentration of 50 and 100 µM significantly inhibited NO production in PG-induced RAW 264.7 (p <0.05). Conclusions : BA might have anti-oxidative activity related to its inhibition of hydrogen peroxide production in 'LPS and PG'-stimulated RAW 264.7 macrophages.

• Journal of Sensor Science and Technology
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• v.23 no.4
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• pp.278-283
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• 2014

In this study, we propose an immunosensor using zinc oxide nanorods (NRs) inside PDMS channel for detecting the influenza A virus subtype H7N9. ZnO with high isoelectric point (IEP, ~9.5) makes it suitable for immobilizing proteins with low IEP. In this proposed H7N9 immunosensor structure ZnO NRs were grown on the PDMS channel inner surface to immobilize H7N9 capture antibody. A sandwich enzyme-linked immunosorbent assay (ELISA) method with was used 3,3',5,5' tetramethylbenzidine (TMB) for detecting H7N9 influenza virus. The immunosensor was evaluated by amperometry at various H7N9 influenza antigen concentrations (1 pg/ml - 1 ng/ml). The redox peak voltage and current were measured by amperometry with ZnO NWs and without ZnO NWs inside PDMS channel. The measurement results of the H7N9 immunosensor showed that oxidation peak current of TMB at 0.25 V logarithmically increased from 2.3 to 3.8 uA as the H7N9 influenza antigen concentration changed from 1 pg/ml to 1 ng/ml. And then we demonstrated that ZnO NRs inside PDMS channel can improve the sensitivity of immunosensor to compare non-ZnO NRs inside PDMS channel.

• Journal of Environmental Health Sciences
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• v.33 no.5
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• pp.403-407
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• 2007

The inhibitory effect of the food processing agent on growth of Escherichia coli O157:H7, Salmonella Enteritidis, and Listeria monocytogenes was performed with organic acid, and combination of citric acid, acetic acid, propionic acid and vanillic acid. The minimun inhibitory concentration(MIC) of propionic acid was 5,000 ppm in E. coli O157:H7, 2,500 ppm in Salmonella Enteritidis and Listeria monocytogenes. MIC of citric acid was 10,000 ppm in E. coli O157:H7 and Salmonella Enteritidis, 2,500 ppm in Listeria monocytogenes. MIC of acetic acid was 2,500ppm, while in vanillic acid was 5,000 ppm in Escherichia coli O157:H7, Salmonella Enteritidis, and Listeria monocytogenes. MIC of combined organc acid in E. coli O157:H7 were 2,500ppm in PC, 1,250 ppm in PA, PV, CA, CV and AV. MIC of combined organc acid in Salmonella Enteritidis were 2,500 ppm in PC, PA, PV, CA, and CV, 1,250 ppm in AV. MIC of combined organc acid in Listeria monocytogenes were 1,250 ppm in all treatment group. MIC of combined treatment of three organc acid in E. coli O157:H7, S. Enteritidis and L. monocytogenes were 1,250 ppm in PCA, PCV, PAV and CAV. The inhibitory effect of organc acid in E. coli O157:H7, S. Enteritidis and L. monocytogenes could be confirmed from the result of this experiment. Therefore, it was expected that the food process would increase or maintain by using organic acid.

• Korean Journal of Veterinary Research
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• v.38 no.1
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• pp.173-181
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• 1998

Esherichia coli O157 : H7의 slt I, slt II, uid A 및 eaeA 4종 유전자를 동시에 검출하기 위한 multiplex PCR 기법을 확립하고 쇠고기중 직접 E coli O157 : H7 검출시험을 실시하였다. 4 set의 primers를 이용한 multiplex PCR 기법으로 31종의 장내세균에 대한 특이성을 조사한 결과 E coli O157 : H7 에서 1,087bp (eae A), 584bp (slt II), 348bp (slt I) 또는 252bp (uid A)크기의 DNA를 동시에 특이적으로 검출할 수 있었다. E coli O157 : H7 15주는 모두 uid A 및 eae A 유전자가 동시에 검출되었고, 다른 장내세균에서는 검출되지 않았다. slt I 또는 slt II 유전자를 가지고 있는 E coli 표준균주 24종을 이용하여 multiplex PCR 기법과 Vero cell cytotoxicity assay을 비교검사한 결과 베로톡신 산생능과 PCR법의 결과는 일치하였다. mutiplex PCR 기법의 쇠고기중 검출한계는 modified EC(mEC)에서 증균없이는 E coli O157 : H7균 $10^4cells/g$ 이상에서 검출이 가능하였으나 mEC에 1차 증균후 modified TSB 증균하였을 경우에는 10cells/g이하까지도 검출이 가능하였다. 개발된 multiplex PCR 기법을 쇠고기 40종에 직접 적용한 결과 E coli O157 : H7은 검출되지 않았으나 slt I 및 slt II유전자를 가지고 있는 E coli 4종이 검출되었으며, 이들의 혈청형은 O6, O112, O115 및 O139 였다. 이 연구에서 개발된 multiplex PCR은 쇠고기중 E coli O157 : H7을 신속하고 특이적으로 검출하는데 사용할 수 있을 것으로 사료된다.

• The Korea Journal of Herbology
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• v.38 no.1
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• pp.1-9
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• 2023

Objectives : The aim of this study was to investigate the effect of baicalein (BA) on the production of hydrogen peroxide in peptidoglycan-stimulated RAW 264.7 mouse macrophages. Methods : Peptidoglycan-stimulated RAW 264.7 were incubated with baicalein at concentrations of 50 and 100 µM. Incubation time is 30 min, 2 h, 12 h, and 18 h. After incubation, The production of hydrogen peroxide in RAW 264.7 was measured with dihydrorhodamine 123 assay. Berberine and gallic acid were used as the comparative materials. Results : BA at the concentration of 50 and 100 µM did not show cytotoxicity on RAW 264.7 for 24 h incubation. For 30 min, 2 h, 12 h, and 18 h incubation, BA at the concentration of 50 and 100 µM significantly inhibited the production of hydrogen peroxide in RAW 264.7 stimulated by peptidoglycan (p<0.05). In details, production of hydrogen peroxide in peptidoglycan-stimulated RAW 264.7 treated for 30 min with BA at concentrations of 50 and 100 µM was 93.91% and 93.52% of the control group treated with peptidoglycan only, respectively; the production of hydrogen peroxide for 2 h was 93.8% and 92.71%, respectively; production of hydrogen peroxide for 12 h was 94.86% and 95.93%, respectively; production of hydrogen peroxide for 18 h was 95.37% and 96.48%, respectively. Conclusions : BA might have anti-oxidative activity related to its inhibition of hydrogen peroxide production in peptidoglycan-stimulated RAW 264.7 macrophages.

• Korean Journal of Food Science and Technology
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• v.31 no.4
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• pp.1024-1028
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• 1999

Green tea infusions were prepared by extracting them with aqueous solution of different pHs and their physicochemical properties were analyzed. Yellowness, chroma and total color difference values were increased as pH increased. The content of total amino acids in the green tea infusion was not influenced by pH values. Total catechin contents of the green tea infusion extracted at pH 4.0, 5.0, 6.0 and 7.0 were 32.28, 31.84, 31.14 and 14.70 mg/g, respectively. Among the four catechins investigated, epigallocatechingallate and epigallocatechin are more unstable as the pH was changed from 6.0 to 7.0. As pH increased, the extraction of caffeine was also increased. In conclusion, extraction at low pH is preferred for the preparation of green tea infusion.

• Food Science of Animal Resources
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• v.25 no.3
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• pp.340-343
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• 2005

The objective of this work was to study separation of short peptide (glycine-tyrosine) by using supported liquid membranes (SLMs) containing Aliquat as a cationic carrier, In the present investigation, the influence of pH of donor phase, concentrations of carrier and salt concentrations of acceptor phase on separation flux rate were investigated. Below pH 7.0 the flux rate was not affected by NaCl concentration or carrier concentration. However, the rate was increased significantly above pH 7.0. The rate with Hossain's SLM(H-SLM) containing $20\%$ Aliquat was about 3-fold higher with pH 9.0 at 0.25 M NaCl and 10-fold higher with pH 8.0 at 1.0 M NaCl than that with Duggan's SLM(D-SLM) containing $8\%$ Aliquat respectively. Furthermore, the rate with H-SLM was 10-fold higher at 1.0 M NaCl than the rate with 0.25 M NaCl, In conclusion, it would appear that the rate of separation was facilitated by using high salt concentrations together with high carrier concentrations above pH 7.0.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.8
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• pp.378-384
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• 2018

$C_9H_7NHCrO_3Cl$ was synthesized by reacting $C_9H_7NH$ with chromium (VI) trioxide. The structure of the product was characterized by FT-IR (Fourier transform infrared) spectroscopy and elemental analysis. The oxidation of benzyl alcohol by $C_9H_7NHCrO_3Cl$ in various solvents showed that the reactivity increased with increasing dielectric constant(${\varepsilon}$) in the following order: DMF (N,N'-dimethylformamide) > acetone > chloroform > cyclohexane. The oxidation of alcohols was examined by $C_9H_7NHCrO_3Cl$ in DMF. As a result, $C_9H_7NHCrO_3Cl$ was found to be an efficient oxidizing agent that converts benzyl alcohol, allyl alcohol, primary alcohols, and secondary alcohols to the corresponding aldehydes or ketones (75%-95%). The selective oxidation of alcohols was also examined by $C_9H_7NHCrO_3Cl$ in DMF. $C_9H_7NHCrO_3Cl$ was the selective oxidizing agent of benzyl, allyl and primary alcohol in the presence of secondary ones. In the presence of DMF with an acidic catalyst, such as $H_2SO_4$, $C_9H_7NHCrO_3Cl$ oxidized benzyl alcohol (H) and its derivatives ($p-OCH_3$, $m-CH_3$, $m-OCH_3$, m-Cl, and $m-NO_2$). Electron donating substituents accelerated the reaction rate, whereas electron acceptor groups retarded the reaction rate. The Hammett reaction constant (${\rho}$) was -0.69 (308K). The observed experimental data were used to rationalize hydride ion transfer in the rate-determining step.