• 한국식품위생안전성학회지
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• 제37권5호
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• pp.328-331
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• 2022

병원성 미생물에 의한 감염을 일으키는 주요 독성인자 중 하나인 응집 물질은 자가응집 및 미생물막 형성으로 인체 건강에 부정적인 영향을 미칠 수 있다. 본 연구에서 Lacticaseibacillus rhamnosus LRH020 (DSM25568) 균주의 독성 유전자 분석을 통해 asa1 유전자를 확인하였고, 표현형으로의 발현 여부 확인을 위하여 미생물막 형성능과 자가응집능 활성실험을 진행하였다. 실험결과 LRH020은 양성대조군 Escherichia. faecalis ATCC 19433과 비교하였을 때 유의적으로 미생물막 형성능이 낮으며, 비교균주 Lacticaseibacillus rhamnosus GG (LGG)와 자가응집능에 차이가 없음을 확인하였다. 균주 LRH020은 asa1 유전자는 가지고 있으나, 표현형으로는 상업균주 LGG와 유사함으로 잠재적인 프로바이오틱스로서의 안전성을 확인하였다.

• 한국정보시스템학회지:정보시스템연구
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• 제13권2호
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• pp.155-172
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• 2004

The purpose of this study is to investigate factors which can lead small buyers to participate in a Reverse Aggregation Electronic Market (RAEM). Five factors including search, selection, price, delivery, and Internet literacy were selected as possible factors which are expected to influence small buyers' participation in a RAEM. This paper focused on a RAEM of the Korean automotive industry in which the third party aggregator formed a group of small automobile repair shops (ARS) and amassed buying power for them by building a buyer' oriented electronic market (EM). Survey data were collected from small ARS in South Korea. The results of the empirical analysis indicated that fast delivery and support for Internet illiteracy are potential incentives that could influence buyers' decisions to join a RAEM.

• KSBB Journal
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• 제32권2호
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• pp.146-152
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• 2017

Vulvovaginal candidiasis (VVC) is one of the urogenital infections occurring in women worldwide. Candida albicans is generally observed among various types of microorganisms causing VVC. Antibiotic therapy is typical, and the use of Lactobacilli probiotics is to be recognized as a promising alternative. The aim of this study was to select vaginal lactobacilli with probiotic properties against C. albicans. In a previous study, we isolated 38 lactobacilli from vagina of Korean women and 20 isolates were shown to inhibit C. albicans. We further selected 10 isolates which were able to inhibit C. albicans less than $10^5CFU/mL$. Among these selected strains, Lactobacillus salivarius MG242 (identified by 16s rRNA sequencing) was finally selected based on its strong anti-candidal activity, acid/bile salt resistance and adhesion property. Indirect adhesion activity of MG242 measured by auto-aggregation assay showed more than 60% auto-aggregation after 5 h standing. Taken these results together, the selected strain MG242 may have potential for application in vagina health related products.

• Journal of Microbiology and Biotechnology
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• 제32권1호
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• pp.56-63
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• 2022

This study aims to determine the antibiofilm effect of cell-free supernatant (CFS) of Lactobacillus brevis strains against Streptococcus mutans strains. To study the antibiofilm mechanism against S. mutans strains, antibacterial effects, cell surface properties (auto-aggregation and cell surface hydrophobicity), exopolysaccharide (EPS) production, and morphological changes were examined. The antibiofilm effect of L. brevis KCCM 202399 CFS as morphological changes were evaluated by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM), compared with the control treatment. Among the L. brevis strains, L. brevis KCCM 202399 showed the highest antibiofilm effect on S. mutans KCTC 5458. The antibacterial effect of L. brevis KCCM 202399 against S. mutans KCTC 5458 was investigated using the deferred method (16.00 mm). The minimum inhibitory concentration of L. brevis KCCM 202399 against S. mutans KCTC 5458 was 25.00%. Compared with the control treatment, L. brevis KCCM 202399 CFS inhibited the bacterial adhesion of S. mutans KCTC 5458 by decreasing auto-aggregation, cell surface hydrophobicity, and EPS production (45.91%, 40.51%, and 67.44%, respectively). L. brevis KCCM 202399 CFS inhibited and eradicated the S. mutans KCTC 5458 biofilm. Therefore, these results suggest that L. brevis KCCM 202399 CFS may be used to develop oral health in the probiotic industry.

• 대한본초학회지
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• 제25권4호
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• pp.1-6
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• 2010

Objective : The purpose of this study is to compare anti-thrombotic activities of 4 Rhubarb species. Methods : Rhubarb has been used as medical and edible resources worldwide for the therapy of cancer, constipation and inflammation, etc. To compare the anti-thrombotic activities among the species within rhubarb, we investigated and compared the inhibitory properties of water extracts from R. palmatum(RPE), R. officinale(ROE), R. nobile(RNE), and R. franzenbachii (RFE) on the fibrinolysis, blood coagulation and platelet aggregation. APTT and PT, blood coagulation time, were measured by apparatus of auto blood coagulation analysis that called ACL-7000. The measurement of fibrinolysis was measured and compares with the width of clear zone from melted fibrin plate. The platelet aggregation was measured and compared with inhibition rate of aggregation. Results : We found out the best species from rhubarb showing the significant fibrinolytic, anti-coagulant and anti-platelet aggregation activity. Our results show that Rheum nobile (RNE) has the most effective anti-thrombotic activity among 4 tested rhubarb. Conclusions : This study, therefore, RNE will be able to be used the development of drug which is thrombosis treatment.

• 한국축산식품학회지
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• 제35권3호
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• pp.339-349
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• 2015

The objective of this study was to identify lactic acid bacteria (LAB) isolated from kimchi and to evaluate its characteristics and functional properties for application in fermented dairy products as a probiotic or commercial starter culture. Eight stains isolated from kimchi were selected through an investigation of phenotypic characteristics. Two strains (DK211 and DK303) were identified as Lactobacillus plantarum, another two (DK207 and DK215) as Lactobacillus paracasei, and one (DK301) as Lactobacillus sakei. The remaining three strains were identified as species of Weissella. All selected Lactobacillus strains had acid and bile tolerance, even though there was wide variation in the ability of each strain. DK303 showed a remarkably higher proteolytic activity. There were no significant differences in β-galactosidase activity among the tested strains, except that DK301 showed no activity. Auto-aggregation varied between 82.1 and 90.0%, and hydrophobicity values ranged from 0.5 to 51.6%.The strongest auto-aggregation and hydrophobicity were observed in DK211. All selected strains showed better 1,1-diphenyl-2-picrylhydrzyl (DPPH) scavenging activity than commercial strains. DK211, DK215, DK301, and DK303 had effective inhibitory activity against all pathogens tested except E. coli. When selected strains were used for yogurt preparation as a single starter culture, the time required to reach target titratable acidity (0.9) was 11-12 h. The yogurt fermented with DK211 had favorable panelists ratings for most sensory attributes, which were comparable with yogurt fermented with a commercial strain. The results suggest that strains isolated from kimchi could be potential probiotic and starter cultures for use in yogurt manufacturing.

• Journal of Microbiology and Biotechnology
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• 제29권8호
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• pp.1177-1183
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• 2019

Grapefruit seed extract (GSE) is a safe and effective preservative that is used widely in the food industry. However, there are few studies addressing the anti-biofilm effect of GSE. In this study, the anti-biofilm effect of GSE was investigated against biofilm-forming strains of Staphylococcus aureus and Escherichia coli. The GSE minimum inhibitory concentration (MIC) for S. aureus and E. coli were $25{\mu}g/ml$ and $250{\mu}g/ml$, respectively. To investigate biofilm inhibition and degradation effect, crystal violet assay and stainless steel were used. Biofilm formation rates of four strains (S. aureus 7, S. aureus 8, E. coli ATCC 25922, and E. coli O157:H4 FRIK 125) were 55.8%, 70.2%, 55.4%, and 20.6% at $1/2{\times}MIC$ of GSE, respectively. The degradation effect of GSE on biofilms attached to stainless steel coupons was observed (${\geq}1$ log CFU/coupon) after exposure to concentrations above the MIC for all strains and $1/2{\times}MIC$ for S. aureus 7. In addition, the specific mechanisms of this anti-biofilm effect were investigated by evaluating hydrophobicity, auto-aggregation, exopolysaccharide (EPS) production rate, and motility. Significant changes in EPS production rate and motility were observed in both S. aureus and E. coli in the presence of GSE, while changes in hydrophobicity were observed only in E. coli. No relationship was seen between auto-aggregation and biofilm formation. Therefore, our results suggest that GSE might be used as an anti-biofilm agent that is effective against S. aureus and E. coli.

• ETRI Journal
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• 제35권6호
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• pp.1011-1020
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• 2013

In this paper, we present a method for obtaining a high-quality 3D depth. The advantages of active pattern projection and passive stereo matching are combined and a system is established. A diffractive optical element (DOE) is developed to project the active pattern. Cross guidance (CG) and auto guidance (AG) are proposed to perform the passive stereo matching in a stereo image in which a DOE pattern is projected. When obtaining the image, the CG emits a DOE pattern periodically and consecutively receives the original and pattern images. In addition, stereo matching is performed using these images. The AG projects the DOE pattern continuously. It conducts cost aggregation, and the image is restored through the process of removing the pattern from the pattern image. The ground truth is generated to estimate the optimal parameter among various stereo matching algorithms. Using the ground truth, the optimal parameter is estimated and the cost computation and aggregation algorithm are selected. The depth is calculated and bad-pixel errors make up 4.45% of the non-occlusion area.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 추계종합학술대회 논문집(1)
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• pp.481-484
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• 2000

In this paper, we describe the design and implementation of IPv6 LAN. The legacy protocol for Internet is IPv4(IP version 4). The ability of IPv4 is not enough for modern real time multimedia communication services. So IPv6(IP version 6) protocol was suggested to resolve the problems of IPv4. We implemented IPv6 LAN using sTLA(sub Top Level Aggregation identifier) address and KOREN(KOrea Research and Experimental Network). Our IPv6 LAN is connected with 6TAP(Chicago), WIDE(Tokyo), and SingAREN(Singapore). We used a dedicated router, Windows 2000 PC host FreeBSD PC host, Solaris 7 workstation and Solaris 8 workstation for IPv6 NDP(Neighbor Discovery Protocol) protocol test. To support all data services including voice and video, IP protocol should be enhanced because the characteristics of modern network services are requiring QoS(Quality of Service) functions, auto-configuration, security, mobility and so on. So a new IP protocol, IPv6, has been developing to meet the requirements. In this paper, we introduce the implementation method and configuration information of IPv6 LAN.

• Journal of Microbiology and Biotechnology
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• 제30권12호
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• pp.1854-1861
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• 2020

Staphylococcus aureus is one of the most common microorganisms and causes foodborne diseases. In particular, biofilm-forming S. aureus is more resistant to antimicrobial agents and sanitizing treatments than planktonic cells. Therefore, this study aimed to investigate the anti-biofilm effects of cell-free supernatant (CFS) of Saccharomyces cerevisiae isolated from cucumber jangajji compared to grapefruit seed extract (GSE). CFS and GSE inhibited and degraded S. aureus biofilms. The adhesion ability, auto-aggregation, and exopolysaccharide production of CFS-treated S. aureus, compared to those of the control, were significantly decreased. Moreover, biofilm-related gene expression was altered upon CFS treatment. Scanning electron microscopy images confirmed that CFS exerted anti-biofilm effects against S. aureus. Therefore, these results suggest that S. cerevisiae CFS has anti-biofilm potential against S. aureus strains.