• Microbiology and Biotechnology Letters
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• v.30 no.4
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• pp.380-387
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• 2002

To investigate the effects of xylooligosaccharides on the in vitro growth of intestinal bacteria, various species were cultivated individually on the m-PYF medium containing a carbon source (0.5% w/v) such as xylooligosaccharides, isomaltooligosaccharides, fructooligosaccharides and sucrose, respectively. The health-promoting microorganisms such as Bifidobacterium bifidum, Bifidobacterium infantis, Bifidobacterium longum, Lactobacillus casei and Lactobacillus acidophilus grew more effectively by xylooligosaccharides than by other carbon source, though xylooligosaccharides inhibited the growth of Clostridium perfringens, Bacteroides fragilis, Escherichia coli, Staphylococcus aureus and Salmonella typhumurium. At the mixed culture xylooligosaccharides exerted a preferential stimulatory effects on numbers of the health-promoting microorganisms, while xylooligosaccharides inhibited populations of potential pathogens at relatively low level. Xylooligosaccharides also maintained the acidity of culture with Streptococcus mutans, caries-inducing bacteria, over pH 5.0. These results suggest that xylooligosaccharides selectively promote the growth of the health-promoting microorganisms in human intestine and prevent caries by inhibiting acid production from Streptococcu mutans.

• Korean Journal of Microbiology
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• v.43 no.3
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• pp.227-231
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• 2007

Many of antimicrobial components used in the mouthwash have disadvantages such as coloring of periodontal tissue and homing sensation. To find the more biocompatible antimicrobial agent, we have screened the 2,125 kinds of natural plant extracts obtained from by the Plant Extract Bank (Daejeon, Korea). The antimicrobial activity was determined by spectrophotometric growth inhibition assay for the major dental pathogens. For the Porphyromonas gingivalis, 19 plant extracts had an antimicrobial activity, 17 plant extracts for the Prevotella intermedia, 45 plant extracts for the Haemophilus actinomycetemcomitans and 85 plant extracts for the Streptococcus mutans. Among these effective extracts, 8 kind of natural plant extracts had an antimicrobial activity for more than 3 species of dental pathogens. In our experiment, Cudrania tricuspidata, Morus bombycis and Mallotus japonicas have antibacterial effects on the all kinds of major dental pathogens. Therefore these plant extracts have a possibility to be a candidate for major antibacterial components in dental products.

• Journal of Life Science
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• v.20 no.3
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• pp.321-325
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• 2010

Among endogenous oral microflora, Streptococcus mutans plays a critical role in dental plaque formation, which mainly contributes to the development of caries and periodontal disease. Phytochemicals are plant-derived chemical compounds that have been studied as beneficial nutrients to human health. The purpose of this study was to determine the effects of phytochemicals against S. mutans. Among them, oleanolic acid (OA) and 5-(hydroxymethyl)-2-furfural (HF) from Thomson seedless raisins were tested for anti-microbial effects against various clinically important bacteria. OA inhibited the growth of Gram-positive bacteria, but not Gram-negative bacteria. However, HF did not display any antibacterial effect against any of the strains tested. OA also exhibited inhibitory effects in surface adherence and biofilm formation of S. mutans. The results suggest that OA can be utilized as a potential anti-plaque and anti-caries agent by controlling the physiological characteristics of S. mutans on teeth.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.3
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• pp.399-404
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• 2002

The fermented fruit and vegetable mixed broth was prepared by using bacteriocin-producing lactic acid bacteria to evaluate the possibility of developing isotonic beverage with anticariogenic activity. Optimum conditions were also established to produce bacteriocin by a mixed culture system consisting of Lc. lactis and Leu. mesenteroides in a fruit and vegetable mixture. Production of bacteriocin was not observed when both strains were simultaneously innoculated, but pH adjustment of the broth fermented by Leu. mesenteroides to nearneutral pH stimulated the production of bacteriocin by Lc. lactis. The concentration of sodium of the fermented broth was higher than those of commercial products. Color change of the fermented broth was not observed during storage. The fermented broth showed strong inhibitory effect against Streptococcus mutans which is an oral inhabitant with a cariogenic activity. Bacteriocin activity in the fermented broth was retained very stable for 4 weeks at 4$\^{C}$. The results indicated that bacteriocin-producing lactic acid bacteria can be used for the preparation of a Korean style thirst-quenching beverage containing bacteriocin.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.3
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• pp.284-293
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• 2006

We have tested 41 herbal medicines to search for a natural substance with antimicrobial activity against Streptococcus mutans and five types of oral bacteria. We have also investigated antioxidative activity of these herbal medicines. Antimicrobial activity against Streptococcus mutans and five types of oral bacteria was analyzed using ethanol extracts of herbal medicines. Extracts from Illicium verum and Amomum xanthioides showed 98% inhibitory activity against Sterptococcus mutans. The effect of Thuja orientalis on S-1 and Thuja orientalis and Amomum xanthioides on S-2 were 95% and 94%, respectively. Nelumbo nucifera was 94% effective on S-5. The inhibitory activities of the herbal medicines against glucosyltransferase (GTase) were determined using purified from Streptococcus mutans and five types of oral bacteria. Extract from Illicium verum and Amomum xanthioides showed 94% effectiveness on Streptococcus mutans. Amomum xanthioides showed 95% effectiveness on S-1 and Thuja orientalis showed 96% effectiveness on S-5. In antioxidant activities of the herbal medicines, extract from Thuja orientalis showed the highest level of 81.08% DPPH radical scavenging activity and Illicium velum extract also showed high antioxidative activity of 80.45%. Thuja orientalis had a large amount of phenolic compound with $115.24\;{\mu}g/mL$ among the herbal medicines.

• Journal of Technologic Dentistry
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• v.19 no.1
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• pp.175-184
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• 1997

The purpose of this study is to examine the effect of parents knowledge on oral health status toward their children. This study was carried out to investigate and analyze the congnitive degree of dental subjects and public who have an experience to be treated for their teeth on the dental knowledge, operative dentistry, and dental prothesis in the oral health care through the questionnaires. The results are as follows; 1. In questioning the fundamental knowledges, 47.6% of respondents in their thirties said that milk tooth of their children are number 20. Although schooling level of their parents is not rel evant to this survey, 21.9% who have only high-school diploma, said also "number 20". As a conclusion, most parents have a big concern in their children's teeth. 2. 44.0% parents answered, asked "who do decayed teeth sping up, and 26.4% said" It is why children eat sugary. Asked "What is efficient preventive measures decayed teeth", 26.5% said it is very relevant to be in the utilization of F-tooth-paste. 3. For children's good theeth, periodically brushing is the important. Most parents recognized brushing efficient. 4. In questioning the possession amount of decayed teeth, 45.8% have more than four. Usually those parents who have children filled their decayed teeth with artificial or installed with dental prosthesis. As a conclusion age is relevant in this study in P<0.05 level. 5. In asking for efficient starting-year of tooth brushing, 42.6% said that 2 or 3 year age is the most efficient, and especially 80.6% teath children to learn brushing themselves(P<0.05) 6. In surveying the way they obtained dental information, 38.9% were given from mass media, but 90% were once not delivered with the education of dental health. Because parents have been know narrow and deficient information of dental health mass media, experts in dental health have to deliver help their parents to be delivered with systematical dental information. The conclustion of this study can summarized that parent's role very important to their children's tooth health and the education program for systematical dental information should be delivered to their parents.

• Journal of the Korean Society of School Health
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• v.5 no.1
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• pp.20-23
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• 1992

충치등의 구강질병은 예방이 가능하며 일단 발생하면 자연치유란 없고 질병의 진행만 있는 질병으로서 조기발견과 조기치료가 필요하다. 특히 학교연령층에서 폭발적으로 발생되고 있 기 때문에 학교구강보건관리가 중요하지만 선진국처럼 학교구강건강 관리실을 운영하고 전문인력을 상주 배치할 수 없는 현시점에서 예방교육과 조기발견, 조기치료를 위한 정기구강검사 제도는 필수적이다. 현행학교정기구강검사는 결핵, 간염, AIDS 등 질병의 전염문제와 검진비가 현실적이지 못하며 치과의사의 봉사강요형태로 진행되고 있는 문제 등이 있다. 그러므로 래원검진제 같은 의견도 있으나 현행 정기구강검진제를 개선하여 실시하는 것이 현실적이라고 본다. 기수소독문제는 치과의사 1인당 50개 정도의 기구가 준비되고 화학소독제로서 Glutal-dehyde(와이멕스)사용으로 해결될 수 있으며 기타 문제는 검진수가의 현실적 인상과 연계되어 근본적으로 해결될 수 있다.

• Korean Journal of Microbiology
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• v.30 no.3
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• pp.213-217
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• 1992

Glucosyltransferase of Streptococcus mutans NCTC 10449 was purified and characterized. It relates with production of insoluble glucan in dental caries. The molecular weight was estimated to be 152.000. The optimum pH and temperature was 6.5 and $35^{\circ}C$. respectively. The enzyme was stable in alkaline pH. The Michaelis constants of the enzyme for releasing of fructose were 48 mM. Hydrolysis rate of insolut~le glucan by tlextranase was higher in S. mutuns NCTC 10449 than that of strains isolated from saliva.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06a
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• pp.438-441
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• 2011

가상현실기반 충치치료 훈련 시스템에서 필수적으로 구현되어야 하는 부문은 절삭도구인 버(bur)를 이용하여 치아를 삭제하는 과정이다. 치아에 비하여 시술도구의 크기가 상대적으로 매우 작기 때문에 보다 정교한 충돌감지뿐만 아니라 치아 삭제에 따른 형태변형에 동기화된 정확한 충돌 모델이 요구된다. 따라서 본 논문에서는 디스턴스 필드를 이용한 볼륨 모델을 치아에 적용하고 이를 형태변형 시각화와 햅틱 렌더링에 함께 이용하는 실시간 충돌 모델을 제안한다. 또한 안정적인 햅틱 피드백을 위해 버의 포인트 쉘 생성 방법과 시간 응집도에 따른 점 접촉 모델 가속화 방법을 제시한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.11B
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• pp.974-979
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• 2004

In the IEEE 802.1 Ib, DCF provides contention based services and PCF provides contention free services for QoS suppof. DCF uses CSMA/CA (Carrier Sense Multiple Access/collision Avoidance) as an access protocol. In this paper, an enhanced PCF, which gives weights to channels with heavy traffic load, was proposed. The weight is depending on the partial queue length information from STAs. NS-2 simulation results show that the proposed scheme is an promising approach for enhancing the PCF.