• Investigative Magnetic Resonance Imaging
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• v.11 no.1
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• pp.39-48
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• 2007

Purpose : To determine the diagnostic accuracy of four different sequences : moderately T2 weighted, two heavily T2-weighted single shot turbo spin-echo sequence and breath-hold axial-2D balanced turbo field-echo sequence(bFFE) for characterization of focal lesions. Materials and Methods : During the 3-month period between June and August 2005, seventy-six patients were proved to have ninety-three focal hepatic lesions on MR imaging. The patients consisted of 49 men and 27 women (age range, 15-75 years; mean age, 56.23 years). All MR images were acquired on a 1.5-T MR using the following sequences: 1. A breath-hold axial T2-weighted single shot turbo spin-echo sequence, 2. a breath-hold axial-2D balanced turbo field-echo sequence. Two radiologists performed quantitative analysis. Another radiologist measured the lesion-to-liver contrast-to-noise ratio at the region-of-interest in the four sequences. Results : There was no significant difference in inter-observer variability between the four sequences. The accuracy for both cyst and malignancy of moderate T2 weighted MRI (echo time: 80 msec) was also highest. There was significant difference for lesion characterization between moderate T2 weighted MRI and balanced steady state procession (p-value: 0.004) in the second reader. For longer echo time, the CNR of cystic lesions were markedly increased in comparison to lesions of other component. Conclusion : The accuracy and inter-observer variability of single shot turbo spin echo T2 weighted sequence was higher than bFFE. Although there was no statically significant difference, moderate T2 weighted MRI (echo time: 80 msec) was more accurate than heavily T2 weighted sequence (echo time: 300 msec). If the results for lesion characterization is equivocal in TE 80, the addition of heavily T2 weighted MRI (echo time: 180 msec) can be helpful.

• Microbiology and Biotechnology Letters
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• v.1 no.1
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• pp.51-57
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• 1973

2,2'-Methylene bis (3,4,6-trichloroacetoxy benzene) had been synthesized from Hexachlorophene. The eleven new derivatives -(2,2'Methylene bis [3,4,6-trichloro o-(${\beta}$-anilinopropionoxy) benzene]: m. p 173∼4$^{\circ}C$, C$\_$31/H$\_$24/N$_2$O$_4$Cl$\_$6/, 2,2' Methylene bis [3,4,6-trichloro (${\beta}$-Cyclohexylaminopropionoxy) benzene]: M. P, 187∼8$^{\circ}C$, C$\_$31/H$\_$36/N$_2$O$_4$Cl$\_$6/, 2,2'-Methylene bis [3,4,6-trichloro (${\beta}$-phenyl hydrazinopropionoxy) benzene]; M. P. 151∼3$^{\circ}C$, C$\_$33/H$\_$28/N$_2$O$_4$Cl$\_$6/, 2,2'-Methylene bis [3,4,6-trichloro (${\beta}$-o-toluidinopropionoxy) benzene]: M. P. 172∼3$^{\circ}C$, C$\_$33/H$\_$28/N$_2$O$_4$Cl$\_$6/, 2,2'-Methylene bis [3,4,6-trichloro (${\beta}$-p-todudinopropionoxy) benzene]: 153∼4$^{\circ}C$, C$\_$33/H$\_$28/N$_2$O$_4$Cl$\_$6/, 2,2'-Methylene bis [3,4,6-trichloro (${\beta}$-o-chloro anilinopropionoxy) benzene]: 170∼2$^{\circ}C$, C$\_$31/H$\_$27/N$_2$O$_4$Cl$\_$8/, 2,2'-Methylene bis [3,4,6-trichloro (${\beta}$-p-sulfamilinopropionoxy) bengene]: M. P. 310-5$^{\circ}C$, C$\_$31/H$\_$24/N$_2$S$_2$O$\_$10/Cl$\_$8/, 2,2'-Methylene bis [3,4,6-trichloro (${\beta}$-piperidinopropionoxy) benzene]: M. P. 168∼2$^{\circ}C$, C$\_$29/H$\_$32/N$_2$O$_4$Cl$\_$6/, 2,2'-Methylene bis (3,4,6-trichloro (${\beta}$-morpholinopropionoxy) benzene]: M. P. 226∼8$^{\circ}C$, C$\_$27/H$\_$28/N$_2$O$\_$6/Cl$\_$6/, 2,2'-Methylene bis (3,4,6-trichloro (${\beta}$-2-amino pyridino propionoxy) benzene]; M. P. 145∼6$^{\circ}C$, C$\_$29/H$\_$22/N$_4$O$_4$Cl$\_$5/-were synthesized by Mannichs reaction as potential antimicrobial agents and their antimicrobial activity were tested against Bacillus subtilis, Pseudomonas ovalis, Escherichia coli, Staphylococcus aureus, aerogenes, Bacillus Acerobacter Polymyxa, Bacillus brevis, Streptomyces griseus, Candida troficalis, Rhodotorula glutinis, Candida utilis, Hansenula anamola, Saccharomyces cerevisiae in vitro. Among them, compounds of benzylamine and p-toludine showed an effective antimibrobial activity againt Bacillus subtilis and Pseudomonas ovalis.

• Korean Journal of Food Science and Technology
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• v.41 no.3
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• pp.296-301
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• 2009

In order to investigate the effect of different yeasts (La Parisienne (LP), Y18-2, Y54-3, Y90-2, Y90-9 and Y272-7) from nuruks on the quality of Glutinous rice wines, physicochemical properties and volatile flavor components were evaluated. Glutinous rice wines prepared with different yeasts were analyzed for ethanol, pH, total acid, amino acid, soluble solid, coloring degree, UV absorbance, reducing sugar, organic acid, free sugar and volatile compounds. After fermentation for 17 days, the ethanol contents ranged from 13.40 to 14.50%, while the total acid levels were from 0.33 to 0.44%. The amino acid contents in six samples ranged from 0.13 to 0.18%, while soluble solid contents ranged from 12.1 to $14.7^{\circ}Bx$. The glutinous rice wine prepared with LP showed the highest level of coloring degree, soluble solid and reducing sugar among six samples. Organic acid contents of the glutinous rice wine prepared with LP had the highest levels of lactic acid and acetic acid, while the glutinous rice wine prepared with Y90-9 had the highest level of succinic acid. In all glutinous rice wines tested, the most abundant free sugars were glucose followed by maltose. Volatile flavor components in the glutinous rice wines were identified by using GC-MSD. Nineteen esters, ten alcohols, eight acids, one aldehyde and one miscellaneous compound were identified in the glutinous rice wines. Using relative peak area, it was found that other than ethyl alcohol, hexadecanoic acid ethyl ester was the major component, predominantly found in the range of 2.73-10.41%. Phenylethyl alcohol, isoamyl alcohol, ethyl oleate, ethyl linoleate and tetradecanoic acid ethyl ester were some of the major volatile components present through the fermentation, respectively. Overall, it was shown that different yeast strains from nuruks greatly affected chemical and volatile characteristics of the glutinous rice wines.

• Pediatric Infection and Vaccine
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• v.24 no.3
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• pp.168-177
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• 2017

Purpose: The purpose of this study was to analyze the clinical features and risk factors of invasive infections caused by Lactobacillus spp. and Saccharomyces spp., components of commercially available probiotics. Methods: We analyzed demographic and clinical data from children ${\leq}18$ years of age with an invasive infection caused by Lactobacillus spp. or Saccharomyces spp. at the Asan Medical Center Children's Hospital from January 1998 to June 2016. Probiotic consumption data were also analyzed. Results: During the study period, a total of 24 episodes of invasive infections were caused by Lactobacillus spp. (n=16) and Saccharomyces cerevisiae (n=8). Along with the increase of probiotic use (755,594 [days/1,000 patient-admission days] in 2001 to 2005, 1,444,066 in 2006 to 2010, and 6,904,736 in 2011 to 2016), the incidence of probiotic-associated invasive infection increased ($R^2=0.70$). The median age of the patients was 1.8 years (range, 2 months to 17 years), and most of them had underlying medical conditions. The 30-day mortality rate was 20.8% (5/24), and 11 (45.8%) of these patients resulted from a severe invasive infection. We determined the risk factors for invasive infection to be: previous intensive care unit stay (odds ratio [OR], 3.0; 95% confidence interval [CI], 1.5 to 6.1] and the presence of a central venous catheter (OR, 2.2; 95% CI, 1.2 to 4.3). Conclusions: Although the probiotic-associated invasive infections rarely occurred in children, the incidence has increased along with probiotic pressure. Judicious use of probiotics is mandatory, especially in young children with underlying medical conditions and continuous surveillance will be needed to minimize the safety concerns.

• Journal of Food Hygiene and Safety
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• v.35 no.5
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• pp.503-512
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• 2020

To enhance the usability of puffed rice, we evaluated the quality characteristics and antioxidant activity of vinegar made with puffed rice and lemon balm. First, puffed rice containing lemon balm extracts was fermented for alcohol production. The alcoholic fermented liquid was adjusted to an alcohol content of 6% and an initial acidity of 2% for vinegar fermentation. The pH and alcohol content of the lemon balm vinegar decreased overall as fermentation progressed. The total acidity was 5.20±0.01% (2.0% lemon balm) to 5.80±0.01% (0.0% lemon balm) on the 15th day of fermentation, and the total acidity was slightly lower as the amount of added lemon balm was increased. Citric, succinic, and acetic organic acids were detected in the vinegar and the acetic acid content was highest at 4.81% to 5.37% on the 15th day of fermentation. We found that the total polyphenol and total flavonoid content of the lemon balm vinegar increased as we added lemon balm, and the content on the 15th day of fermentation was 179.4±4.5 (0.0% lemon balm) - 340.8±2.6 mg/kg (2.0% lemon balm) and 1.5±0.3 (0.0% lemon balm) - 31.7±0.3 mg/kg (2.0% lemon balm), respectively. The higher the amount of lemon balm added, the higher the DPPH radical scavenging activity, the FRAP (reducing power), and the ABTS radical scavenging activity. Moreover, those activities after 2.0% lemon balm treatment were 82.99±0.61%, 1.08±0.01 abs., and 87.67±0.68%, respectively, on the 15th day of fermentation. These results suggest that vinegar with added lemon balm may be used as an antioxidant agent.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.8B
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• pp.691-700
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• 2006

Based on the destination IP address of incoming packets, the Internet routers determine next hops and forward packets toward final destinations through If address lookup. The bandwidth of communication links increases exponentially fast as well as the routing table size grows significant as the number of single host networks attached to the Internet increases. Since packets should be processed at wire-speed, the increased link speed reduces the processing time of a packet in routers, and hence more efficient and fast IP address lookup algorithms and architectures are required in the next generation routers. Most of the previous IP lookup schemes compare routing prefixes of shorter length first with a given input IP address. Since IP address lookup needs to find the most specific route of the given input, search continues until the longest matched prefix is found while it keeps remembering the current test matching prefix. In this paper, based on binary search on prefix length, we proposed a new IP address lookup algorithm which compares longer prefixes first. The proposed scheme is consisted of multiple tries with prefixes on leaves only. The trie composed of the longest prefixes is primarily searched whether there is a match with the given input. This processing is repeated for the trio of the next longer prefixes until there finds a match. Hence the proposed algorithm provides the fast search speed. The proposed algorithm also provides the incremental update of prefixes while the previous binary search on length scheme does not provide the incremental update because of pre-processing requirement. In this paper, we performed extensive simulations and showed the performance comparisons with related works.

• Microbiology and Biotechnology Letters
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• v.38 no.2
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• pp.190-197
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• 2010

To develop the safe and natural antimicrobial agents, the 68 ethanol extracts from the 61 different kinds of oriental herbal medicine were prepared and their antimicrobial activities were evaluated. The herbal medicine used were from China (46 kinds), South Korea (14 kinds), North Korea (5 kinds) and Vietnam (3 kinds), respectively, and the root (27 species) was popular part in this study. The average water content and extraction ratio for ethanol were 7.10% and 6.75%, respectively. Determination of antimicrobial activity by disc-diffusion assay at 0.5 mg/disc concentration showed that the extract of Angelica tenuissima Nakai (china), Illicium verum, Junci medulla, Rhus javanica L., Salvia miltiorrhiza Bunge and Syzygium aromaticum has strong antimicrobial activities against different food spoilage and pathogenic bacteria and fungi. Determination of MIC and MBC/MFC further showed that the extract of Syzygium aromaticum has MIC of 1.25 mg/mL and MBC/MFC of 1.25~5.00 mg/mL against Listeria monocytogenes, Bacillus subtilis, Staphylococcus epidermidis, Staphylococcus aureus, Salmonella typhimurium, Proteus vulgaris, Escherichia coli, Pseudomonas aeruginosa, Candida albicans and Saccharomyces cerevisiae. And, the extract of Junci medulla, Rhus javanica L. and Salvia miltiorrhiza Bunge showed strong antibacterial activities with MIC of 0.08~0.63 mg/mL and MBC/MFC of 0.08~2.50 mg/mL against the tested bacteria except E. coli and P. aeruginosa. In a while, the results of hemolytic activity of 68 different herbal extracts against human red blood cells showed that the extract of Angelica tenuissima Nakai has hemolytic activity at 0.5 mg/mL concentration. Therefore, Illicium verum, Junci medulla, Rhus javanica L., Salvia miltiorrhiza Bunge and Syzygium aromaticum were finally selected for natural antimicrobial resources. Further research on active substances and the mode of action of the selected herbal medicine is necessary.

• Korean Journal of Food Science and Technology
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• v.42 no.2
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• pp.155-159
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• 2010

The antimicrobial activity of Sargassum fulvellum (SF) was investigated using the agar diffusion assay and MIC test. In addition, the stability of this activity under extreme heat and pH conditions was examined. The SF ethanol extract was shown to display strong antimicrobial activities against B. subtilis, C. perfringens, L. plantarum, S. aureus, L. monocytogenes, S. cerevisae and C. tropicalis in the agar diffusion assay at the concentration of 4 mg/mL. The MIC value of the SF ethanol extract against the tested microbes ranged from 0.05 to 0.0063%. In the heat and pH stability test, the antimicrobial activity of the SF ethanol extract was not altered when the temperature was maintained at $121^{\circ}C$ for 15 min, and it was also not affected in the pH range of 2-10. These results suggest that the SF ethanol extract is highly stable against drastic changes in temperature and pH.

• Korean Journal of Food Science and Technology
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• v.49 no.4
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• pp.383-389
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• 2017

This study aimed to select a yeast strain for optimizing the quality of distilled spirits. The brewing and distilling properties of 4 KFRI (Korea Food Research Institute) yeasts (Y88-4, Y98-4, Y172-6, Y192-4) and 2 industry yeasts (C1, C2) were compared. For investigating the possibility of using these strains on an industrial scale, diverse analytical methods were applied to assess parameters associated with distilled spirit quality such as alcohol content, pH, total acidity, and soluble solid content. After 11 days of fermentation, the alcohol strength obtained using six yeast strains reached 13.9-16.4% (v/v), while pH was 3.9-4.0, and total acid was 0.40-0.52%. To compare GC-MSD Volatile flavor components, all the distilled spirit samples were diluted to 20% (v/v) alcohol strength. Seven fusel alcohols, 26 esters, 2 acids, and 3 miscellaneous compounds were detected in the distilled spirits. Y88-4 had the most abundant volatile flavor component and scored the highest overall preference in sensory evaluation. After analyzing the various properties of yeasts, strain Y88-4 was finally selected as the best strain for producing distilled spirits.

• Korean Journal of Food Science and Technology
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• v.50 no.1
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• pp.98-104
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• 2018

Oxyresveratrol (trans-2, 3', 4, 5'-tetrahydroxystilbene), found in many plants including grape, peanut and mulberry, is a phytoalexin, an antimicrobial and antioxidative substance that rapidly accumulates in areas infected by the pathogen. We examined the accumulation of oxyresveratrol in nine Morus alba L. cultivars with respect to storage time and temperature postharvest and infection with GRAS microorganisms. Among the nine cultivars, the Suwon cultivar showed the highest oxyresveratrol content (9.6-fold increase) postharvest, when stored at $30^{\circ}C$ for 7 days. The optimal temperature and postharvest storage time for oxyresveratrol accumulation was $30^{\circ}C$ and 6 days. When Ramulus mori was infected with five microorganisms, the accumulation of oxyresveratrol increased over 4-fold in response to B. coagulans infection. These results suggest that oxyresveratrol accumulation is influenced by storage temperature, storage time, Ramulus mori cultivars, and microbial attack. Therefore, postharvest storage for an appropriate time period at a suitable temperature might be a useful way to industrially produce Ramulus mori cultivars with high oxyresveratrol content.