• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.04b
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• pp.157-159
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• 2000

Vanadate glass in the $Li_2O-P_2O_5-V_2O_5$ system with 60mol% $V_2O_5$ was prepared by melting the bath in pt. crucible followed by quenching on the copper plate. We found that $Li_2O-P_2O_5-V_2O_5$ glass ceramics obtained from nucleation of $Li_2O-P_2O_5-V_2O_5$ glass showed significantly higher capacity and longer cycle life than conventionally made crystalline $LiV_3O_8$. In the present paper, We describe the charge/discharge properties during crystallization process and find the best crystallization condition of $Li_2O-P_2O_5-V_2O_5$ glass as cathode material. The Charge and discharge capacity of $Li_2O-P_2O_5-V_2O_5$ glass was about 220mAh/g for the cell heat-treated at $250^{\circ}C$ for 2.5hr.

• Korean Journal of Food Science and Technology
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• v.45 no.4
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• pp.526-529
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• 2013

This study was conducted to evaluate the disinfection effects of Staphylococcus aureus, and Escherichia coli treated with 461-nm LED and pH 5 at $15^{\circ}C$ for 10 h. S. aureus strains were decreased by about 4 log CFU/mL after 461-nm LED irradiation treatment alone for 10 h. E. coli strains were inactivated by irradiation. However, when microorganisms were subjected to a combined treatment of 461-nm LED and pH 5, both strains were inactivated by irradiation for 7 h. The highest D-value was 5.05 h for S. aureus ATCC 27664 and the lowest D-value was 1.39 h for E.coli O157: H7 ATCC 35150 (p<0.05) with 461-nm LED irradiation. For the combined treatment (461-nm LED and pH 5), the highest D-value was 1.58 h for S. aureus ATCC 19095, whereas the lowest D-value was 0.83 h for S. aureus ATCC 27664 (p<0.05). These data showed that bactericidal effects of a combination of pH 5 with 461-nm LED irradiation were enhanced compared to 461-nm LED irradiation alone.

• Preventive Nutrition and Food Science
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• v.15 no.3
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• pp.239-243
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• 2010

The antimicrobial effects of a commercially available, buffered sodium citrate (BSC) were evaluated for the reduction of total aerobic bacteria count, Salmonella Typhimurium, Escherichia coli O157:H7, Listeria monocytogenes and Staphylococcus aureus in a liquid medium and ground beef. BSC at 0, 1, 2 and 4.8% (wt/vol) or 0, 3, and 4.8% (wt/wt) was mixed into inoculated brain heart infusion (BHI) broth and ground beef (80% lean), respectively. BSC at concentrations of 1 and 2% did not inhibit growth of the pathogens tested in BHI broth. E. coli O157:H7 in BHI broth with 4.8% BSC was significantly reduced (p<0.05) by 3～4 log CFU/mL compared with the control for up to 4 days. At 4.8%, BSC treatment of ground beef most significantly reduced (p<0.05) total aerobic count and E. coli O157:H7 by 2.1 and 2.0 log CFU/g, respectively. This study indicates that the legally allowable level of 1.3% (wt/wt) BSC is not effective for reducing the pathogens tested in ground beef stored at $7^{\circ}C$.

• Journal of Food Hygiene and Safety
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• v.32 no.1
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• pp.64-69
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• 2017

This study was conducted to investigate the effect of cold plasma combined with UV-C irradiation against Escherichia coli O157:H7, Salmonella enterica serovar Typhimurium, and Listeria monocytogenes on lettuce. E. coli O157:H7, S. Typhimurium, and L. monocytogenes, corresponding to approximately 5.82, 5.09, 5.65 log CFU/g, were inoculated on lettuce, respectively. Then, the lettuce was treated with cold plasma, UV-C and combination (cold plasma + UV-C), respectively. The treated lettuce was stored for 9 days at $4^{\circ}C$ for microbiological analysis and sensory evaluation. Cold plasma reduced the populations of E. coli O157:H7, S. Typhimurium, and L. monocytogenes by 0.26, 0.65, and 0.93 log CFU/g, respectively. Each microorganism were reduced by 0.87, 0.88, and 1.14 log CFU/g after UV-C treatment. And, the combined treatment that was treated by cold plasma after UV-C treatment reduced the populations of inoculated microorganisms by 1.44, 2.70, 1.62 log CFU/g, respectively. The all treatment significantly (p < 0.05) reduced the populations of all inoculated bacteria compared to untreated lettuce. UV-C combined with cold plasma was the most effective for reducing the pathogenic bacteria on lettuce, by showing log-reductions of ${\geq}2.0\;log\;CFU/g$. All treatment was not significantly different until 6 day storage compared to control group in terms of appearance, texture and overall acceptability. Therefore, the combined treatment will be an effective intervention method to control the bacteria on lettuce.

• Korean Journal of Plant Resources
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• v.23 no.5
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• pp.430-435
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• 2010

This study was performed to investigate the antimicrobial effects of Ampelopsis brevipedunculata ethanol-extract on food spoilage or foodborne disease microorganism. The antimicrobial activity of Ampelopsis brevipedunculata extract was determined by a paper disc method. The extract exhibited growth inhibiting activities in a concentration dependent manner on 7 species of microorganisms. The extract of Ampelopsis brevipedunculata showed the highest antimicrobial activity against Escherichia coli O157:H7. The growth inhibitory effects of the extract at the concentration of 250, 500, 1,000, 2,000 mg/L on food poisoning microorganism were determined against Salmonella typhimurium, Yersinia enterocolitica, Escherichia coli O157:H7 and Staphylococcus aureus. The growth of microorganisms was not affected by the extract at the concentration up to 250 mg/L, but was significantly (p<0.05) inhibited by the extract at the concentration higher than 500 mg/L. The results in the present study demonstrate antimicrobial effects of Ampelopsis brevipedunculata ethanol-extract against foodborne pathogens, suggesting that Ampelopsis brevipedunculata could be an effective natural antibacterial agent in food.

• Korean Journal of Veterinary Research
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• v.41 no.2
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• pp.189-195
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• 2001

Single base substitution and deletion mutation have been introducted into the verotoxin 2 (VT2)A subunit gene from O157:H7 isolates to reduce cytotoxicity of VT2 and the cytotoxicity between wild type toxin and mutant toxoid were compared. A M13-derived recombinant plasmid pEP19RF containing a 940bp EcoRI-PstI fragment of VT2A gene was constructed for oligonucleotide-directed mutagenesis. The duoble mutant pDOEX was constructed by point and deletion mutation of two different highly conserved regions of VT2A encoding active site cleft of enzymatic domain. The key residue, Glu 167(GAA) and the pentamer(WGRIS) consisting of the enzymatic domain were replaced by ASP(GAC) and completely deleted in nucleotide sequence analysis of mutant, respectively. In the comparision of vero cell cytotoxicity between wide type toxin and toxoid from mutant, the wild type toxin expressed cytotoxicity in dilution of $10^{-6}$, but the toxid from mutant did not show cytotoxicity to vero cells.

• Journal of Food Hygiene and Safety
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• v.22 no.3
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• pp.151-158
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• 2007

Among 68 strains of lactic acid bacteria (LAB) isolated from Dongchimi, a strain K11 was selected due to its bactericidal activity against Escherichia coli O157 The strain K11 was identified as Lactobacillus plantarum, based on physiological and biochemical characteristics. In the late exponential phase, La. plantarum K11 showed maximum bacteriocin activity (12,800 BU/mL) and maintained until the early stationary phase. The bacteriocin activity was completely inactivated by all the proteolytic enzymes such as pepsin, protease, proteinase K, papain, chymotrypsin, and trypsin, but the activity was not affected by catalase, a-amylase, lysozyme, and lipase, suggesting proteinaceous nature of the bacteriocin. Additionally, this activity was not affected in the pH range from 3.0 to 9.0 and under storage conditions like 30 days at -20,4, or $25^{\circ}C$. Although the bacteriocin activity was absolutely lost after 15 min treatment at 121, it was relatively stable at $70^{\circ}C$ for 60 min or $100^{\circ}C$ for 30 min. The activity was disappeared by treatment with acetone, benzene, ethanol, or methanol, but it was not affected by treatment with chloroform or hexane. The antibacterial activity of the bacteriocin was good against some LAB including Lactobacillus spp., Enterococcus spp., and Streptococcus spp., but not against food-borne pathogens such as Bacillus spp., Listeria spp., and Staphylococcus spp. as well as yeasts and molds. Especially, some intestinal bacteria such as Enterobacter aerogenes and E. coli were significantly affected by the bacteriocin of La, plantarum K11. Furthermore, the addition of 640 BU/mL resulted in the complete clearance of E. coli O157 after 10 hr.

• Journal of the Korea Convergence Society
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• v.8 no.2
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• pp.157-162
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• 2017

Inorganic stiffening agents were prepared by mixing paper sludge incineration ash, blast furnace slag fine powder quicklime, anhydrous gypsum and fly ash. The main components of the solidifying agent developed for sludge treatment were SiO, $Al_2O_3$, $TiO_2$, $Fe_2O_3$, $Mn_2O_3$, CaO, MgO, $Na_2O$, $K_2O$, $P_2O$, and $SO_3$. Unlike cement, the developed solidifying agent did not contain $Cr^{6+}$, which is known as a carcinogen. Heavy metals and oil contaminated soil were mixed with solidifying agent and cured for 7 days and the heavy metal content was below the environmental standard. Sewage sludge cake, food waste and solidifying agent were mixed with each other, and after 7 days curing, soil component test showed that the heavy metal content was below the environmental standard. After mixing the sludge, solidifying agent and additive mixture into the beaker, the ammonia concentration was measured to be 0 after 3 days.

• Korean Journal of Plant Resources
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• v.15 no.1
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• pp.67-71
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• 2002

In order to determine the optimum level of three major fertilizers for Saururus chinensis, we applied to the soil at a rate of N(0, 4, 7, 10kg/10a), P$_2$O$\_$5/(0, 1.5, 3, 4.5kg/10a) and K$_2$O(0, 3, 6, 9kg/10a) prior to seeding. Regarding physical properties after the application, the values of pH, OM, Mg, CEC and EC were higher than those of the pre-application, but the contents of P$_2$O$\_$5/, K and Ca were lower. With application of three major fertilizers, dry weight of leaves per 10a was 26∼108kg greater than that of control(281kg) and dry weight of root tuber was higher by 19∼157kg than that of control(610kg). In regression equation of fertilizer recommendation for two-year-old Saururus chinensis, the optimum level of N-P$\_$2/O$\_$5/-K$\_$2/O fertilizer was determined by 7.1, 2.5, 4.2kg/10a, respectively.

• Journal of the East Asian Society of Dietary Life
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• v.22 no.1
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• pp.109-119
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• 2012

This study analyzed the antibacterial activity of the ethanol extract of Schizandra chinensis Baillon against food pathogenic microorganisms to determine its capabilities as a natural antimicrobial agent. A paper disc diffusion test, minimum inhibitory concentration (MIC) determination, and time-kill assay showed that the ethanol extract strongly inhibits the growth of Listeria monocytogenes, Bacillus cereus, Escherichia coli O157:H7, and Pseudomonas aeruginosa. Release of cytoplasmic ${\beta}$-galactosidase was detected in E. coli, E. coli O157:H7, S. aureus, and P. aeruginosa treated with the ethanol extract. An increase of outer membrane permeability caused by the ethanol extract was also observed. An outward flow of cell constituents was detected in the Gram negative strains treated with the ethanol extract. These results imply that the inner and outer membranes of cells were partially destroyed and cell constituents were released by the treatment of the S. chinensis Baillon ethanol extract. The results of this study indicate that ethanol extract of S. chinensis Baillon evidences a fairly good antibacterial effect.