• Journal of the Korean Society of Food Culture
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• v.20 no.5
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• pp.603-607
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• 2005

Fourteen phenolic compounds(benzoic acid, p-hydroxybenzoic acid, protocatechuic acid, vanillic acid, syringic acid, gallic acid, caffeic acid, ferulic acid, (+)-catechin, quercetin, rutin, catechol, chlorogenic acid and L-ascorbic acid) were examined for their effects on the anticarigenic activity. Among tested samples, catechol was significantly inhibited the S. mutans, exhibiting an clear zone 18.5-19.5mm by 10 mg/disc level. The minimal inhibition concentration(MIC) of the phenolic compounds for Streptococcus mutans, M1 and M2 strain were determined as 2,000 ppm, whereas catechol was 1,000 ppm. The activity of glucosyltransferase(GTase) was significantly inhibited by catechol, at 10 ppm(58.7%), 50 ppm(60.7%) and 100 ppm(88.4%) and 500 ppm(89.6%), respectively. Among them, catechol showed most significant anticariogenic activity as well as inhibition of GTase activity.

• Journal of dental hygiene science
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• v.9 no.5
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• pp.485-490
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• 2009

The purpose of this study was to obtain basic data for improvement about oral health education, contents and method for college and university students. A question was used 10 questionnaire by 332 college and university students in the Tae gu-city and Gu mi-city. In conclusion, 1. They answered that dental caries cause is 'No-brushing'(88.3%). The man respondents answered that the cause of periodontal disease is 'weak disease'(39.2%). 2. The reason about visit to dental clinic is 'for treatment'(72.0%) and they answered that the tooth is 'very important in their life'(82.5%). 3. They answered that the frequency of tooth-brushing is 'two times in a day'(44.8%) and using auxiliary oral hygiene material is 'dental floss' by male(15.2%) and female(16.6%). 4. In the case of high oral health knowledge level showed high response rate about level of oral health attitude and oral health recognition.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.2
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• pp.149-154
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• 2007

An antibacterial substance to the Streptococcus mutans, a causative bacterium for decayed teeth, was isolated from the dried sea mustard, Undaria pinnatifida, and identified by GC and GC/MS. Acetone extract from the sea mustard (10.4 kg), was evaporated and partitioned to 4 fractions such as hexane, chloroform, butanol and water. The most active chloroform fraction were further purified through basic alumina, silicic acid and ODS column, successively, and finally, 3 antibacterial substances were isolated on the HPLC attached ODS column by using 95% MeOH and guided with UV detector (254 nm). Antibacterial substances (total 160mg, yield $1.5\times10^{-3}$%) had the same Rf value (0.42) on the TLC developed hexane diethyl ether acetic acid (80:30:1) and those methyl esters moved to 0.95. They were identified as the same unsaturated fatty acid, $C_{18:4,\;n-3}$ (3,6,9,12-octadecatetraenoic acid, stearidonic acid) compared relative retention times (15.5 min) with authentic fatty acid on the GC chromatogram. It was further confirmed unambiguously on the GC/MS giving molecular ion peak at m/z 290 which coincided with its methyl ester.

• Journal of dental hygiene science
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• v.6 no.1
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• pp.47-53
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• 2006

This study is performed both for notification of knowledge level about water fluoridation program for residents of Haeundae, Busan and for finding out the purpose of solving methods of problems which could appeared in water fluoridation program, it has resulted by the survey of 460 Haeundae citizens from August 5, 2005 thru 20th of same month. 1. The drinking water for Haeundae Residents is occupied of 42.8% of the purified water and 31.3% of public tap water, among these, the cooking water is consist of 48.3% of the tap water and 35.4% of the purified water. 2. 35.7% of participants has already known about the water fluoridation program, but 42.0% hasn't, 22.4% were no answer. 3. For the question why water fluoridation program has done 42.0% answered for caries prevention, 32.3% for disinfection of tap water and 15.0% for tap water purification. 4. For water fluoridation program, 78.0% approved and 22.0% disapproved, among reasons 51.0% of approvals were caries prevention and 38.6% of disapproval were that fluorine can be harmful for the human body. 5. There is a fact that fluorine is contained in food, beverage, water, and air, only 21.3% has notified that fact, on the other hand 78.7% hasn't, among teens, 93.5% doesn't know the fluorine containing facts. 6. In the safety notification rate of water fluoridation program, 39.3% notifies it safe, 55.7% showed unknown response, and the speech 28.3% may be the best way to notify it.

• Journal of Korean society of Dental Hygiene
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• v.23 no.5
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• pp.343-350
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• 2023

Objectives: Water constitutes a majority of the human body and is essential for health. In addition, water intake can prevent dental caries by improving salivary lubrication and self-cleaning. This study aimed to determine the relationship between the amount of daily water intake and the symptoms of oral disease in Korean adolescents. Methods: We used data from the Korea Youth Risk Behavior Web-based Survey (KYRBS), conducted in Korea in 2021, and identified the relationship between daily water intake and oral disease symptoms in Korean adolescents. KYRBS is a nationwide cross-sectional survey conducted by the Korea Disease Control and Prevention Agency (KDCA), and a total of 54,848 participants were included in this study. Results: After adjusting for confounding factors, logistic regression analysis showed that tooth pain was more often experienced by those who drank less than two cups of water per day (odds ratio [OR]: 1.14; 95% confidence interval [CI]: 1.01-1.30) than those who drank five or more cups of water per day. Conclusions: A low daily water intake is associated with tooth pain, a symptom of dental caries. The results of our study suggest that increasing water intake may reduce dental caries. Therefore, adequate water intake may help prevent dental caries.

• The Journal of the Korean dental association
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• v.50 no.9
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• pp.544-551
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• 2012

Dental caries is a biofilm-related oral disease, and continues to afflict the majority of the world's population. Although fluoride, delivered in various modalities, remains the mainstay for the prevention of caries, additional approaches are required to enhance its effectiveness. Natural products have been used as a major source of innovative and effective therapeutic agents throughout human history, and have shown promise as a source of components for the development of new drugs. In addition. studies using natural products to prevent or treat oral diseases such as dental caries have received a great deal of attention. A number of compounds, such as epicatechin, allicin and sanguinarine, isolated from natural products, have also been investigated for their efficacy against oral microbial pathogens. However, the use of natural products as an anti-caries agent in clinical practice was controversial because of inadequate knowledge concerning their mechanisms of action and chemical characterization. This study focuses on the current knowledge of natural products in dental caries prevention and suggests natural products are importance sources for the prevention of dental caries.

• Journal of the Korean Institute of Intelligent Systems
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• v.7 no.4
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• pp.74-81
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• 1997

This paper proposes an evolutionary learning algorithm to discipline the projection neural nctworks (PNNs) with special type of hidden nodes which can activate radial basis functions as well as sigmoid functions. The proposed algorithm not only trains the parameters and the connection weights hut also c~ptimizes the network structure. Through the structure optimization, the number of hidden node:; necessary to represent a given target function is determined and the role of each hidden node is decided whether it activates a radial basis function or a sigmoid function. To apply the algorithm, PNN is realized by a self-organizing genotype representation with a linked list data structure. Simulations show that the algorithm can build the PNN with less hidden nodes than thc existing learning algorithm using error hack propagation(EE3P) and network growing strategy.

• Journal of Korean Society for Atmospheric Environment
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• v.17 no.3
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• pp.251-258
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• 2001

Indoor and outdoor nitrogen dioxide(NO$_2$) concentrations of 122 houses were measured and compared with measurements of personal NO$_2$ exposure simultaneously . Time activity patterns were used to determine the impacts on NO$_2$ exposure assessment and time weighed average model to estimate the personal NO$_2$ exposure. Most people spent their times more than 80% of indoor and more than 50% in home, respectively. Personal NO$_2$ esposure was found to be significantly associated with both indoor NO$_2$ concentration(r=0.70) and outdoor NO$_2$ concentration (r=0.68). Using time weighted average model, personal NO$_2$ exposure was estimated with NO$_2$ measurements in indoor home, indoor workplace and outdoor home. The estimated NO$_2$ measurements were significantly correlated with measured personal exposures(r=0.69, N=122). For the difference between measured and estimated NO$_2$ exposures by multiple regression analysis showed that NO$_2$ concentrations in near workplace and other outdoors of no NO$_2$ measurements affected the personal NO$_2$ exposures(p=0.023).

• YAKHAK HOEJI
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• v.34 no.2
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• pp.106-111
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• 1990

The isolation and identification of an antibacterial component, from the leaves of Liriodendron tulipifera. K. Kotch against a cariogenic bacterium Streptococcus mutans OMZ 176, were carried out for developing of anticariogenic agents. The bioactive component was elucidated as ${\beta}-liriodenolide$, which was isolated newly from the leaves of L. tulipifera. The minimal inhibitory concentration (MIC) of ${\beta}-liriodenolide$ was $100\;{\mu}g/ml$ and the antibacterial activity was stronger than that of berberine. ${\beta}-Liriodenolide$ inhibited ${\beta}-lactamase$ activity, 50, 100 and $200\;{\mu}M$ ${\beta}-liriodenolide$ did ${\beta}-lactamase$ activity as 0.7, 3.5 and 19.7%, respectively. The toxicity of ${\beta}-liriodenolide$ was not found with the method of photohemolysis.

• Korean Journal of Pharmacognosy
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• v.22 no.4
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• pp.249-251
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• 1991

The cytotoxic and antibacterial activities of the leaf, the stem and the seed extracts of Luffa cylindrica were evaluated against L1210 cells and Streptococcus mutans OMZ176, respectively. Among hexane, ether, butanol and water fractions, the ether fraction demonstrated the most potent cytotoxic activity, and the $ED_{50}$ values of the ether extract from the leaf, the stem and the seed were 3.5, 3.7 and $13.7{\mu}g/ml$, respectively. Meanwhile, the other fractions showed negligible effect. Separately, it was found that the antibacterial activity of the respective fraction from three parts was insignificant.