• Journal of Digital Convergence
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• v.15 no.1
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• pp.347-353
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• 2017

This study aims to figure out how green tea leaves, mulberry leaves, and mate leaves that are often taken around in drinking tea influence on S. mutans known as dental caries causative bacteria. After vaccinating 1% of S. mutans on the extract added badge and incubating 6 hours and 10 hours in $37^{\circ}C$, it calculated absorbance and bacterial colony number. Extract of green tea leaves and mate leaves were added with 0, 0.5, 1.0, 2.0, and 4.0% of concentration. As a result of growth suppressive effect of S. mutans, it may be observed that colony number significantly decreases in higher concentration. When it calculated bacterial colony number with adding 2% extract after 10 hours, 99.0% for green tea leaves, 97.1% for mulberry leaves, and 89.6% for mate leaves appeared.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.3
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• pp.213-219
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• 2013

We have investigated the correlation between odorous compounds and actinomycetes in drinking water source of Nakdong River in 2011. Geosmin was mainly detected in the spring and summer seasons (Mar, Aug, and Sep) and 2-MIB was mainly detected in the winter and spring seasons (Feb, Mar and May). The odorous compounds concentrations were highest on March which also overlapped with the peak of actinomycetes, geosmin and 2-MIB were detected highly in the diluted culture solution of isolated actinomycetes strains from Nakdong River. For these reasons we could confirm that odorous compounds on March and August are closely related with actinomycetes. Meanwhile, geosmin increase on September supposed to relate with Microcystis.

• Korean Journal of Food Science and Technology
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• v.23 no.6
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• pp.711-716
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• 1991

Various multivariate statistics were applied to determine the relationships between sensory properties of 9 pre-cooked foods. Twelve sensory terms were selected to differentiate the food samples in stepwise discriminant analysis. Three factors accounted for 61.9% of total variation of 12 sensory attributes detected. Factor I was highly related to the qualitative sensory terms, while factor II to the quantitative ones. The principal component plot made it possible to define the relationships between sensory properties and food samples. In cluster analysis using average linkage and Ward's method, nine pre-cooked foods were classified into three clusters in terms of their sensorial similarities.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.4
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• pp.516-523
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• 2015

This study investigated the antimutagenic and anticancer effects of Platycodon grandiflorum extract (PGE) and its fractions against carcinogenic N-nitrosodimethylamine (NDMA) and genotoxicity. The Ames Salmonella mutagenicity test employing histidine mutants of Salmonella Typhimurium TA98 and TA100 was used to examine the mutagenicity of PGE and its fractions. Bacterial reversion assay with S. Typhimurium TA98 and TA100 did not show a significantly increased number of revertant colonies. The same test was used to examine the ability of PGE and its fractions to prevent acquisition of N-methyl-N'-nitro-N-nitrosoguanidine- and 4-introquino-line-1-oxide-induced mutations. PGE and its fractions inhibited mutagenesis in a dose-dependent manner. Among the fractions, ethyl acetate fraction from PGE (PGEA) exhibited a higher antimutagenic effect than other fractions. PGE and its fractions suppressed the growth of cancer cell lines, including human cervical adenocarcinoma, human hepatocellular carcinoma, human breast adenocarcinoma, human lung carcinoma, and transformed primary human embryonic kidney cells. In addition, we evaluated the antitumor activity of PGEA and its fractions in sacorma-180 solid tumor-bearing mice. In vivo anticancer activity results showed that PGE and its fractions could more effectively suppress tumor growth than the control. PGEA showed higher in vitro and in vivo anticancer effects than PGE and other fractions, and PGEA inhibited NDMA formation. Thus, we showed that PGEA has antimutagenic and anticancer activities, making it a candidate anticancer material under these experimental conditions.

• The Journal of Korean Society for School & Community Health Education
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• v.20 no.3
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• pp.83-90
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• 2019

Purpose: This study is a repetitive comparative analysis of a qualitative case study that carried out a home visiting oral health education program. Method: This study conducted an interview survey through medical examination by interview before and after the home visiting oral health education and measured some pathogenic microorganism counts in the denture. Results: There was a positive change in the self oral care ability of the elderly at home after home visiting oral health education, including the behavior of self management of dentures, and some pathogenic microorganism counts in the dentures. Conclusion: The home visiting oral health education of home care service centers can improve oral health care for the elderly at home.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.203-203
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• 1994

3) 결과 및 고찰 : 급성독성시험 : 대조군 및 G009투여군(최저 312.5mg/kg, 최고 5000mg/kg) 5용량에서 모두 사망예가 관찰되지 않았다 체중변화에 있어서도 대조군과 투여군 사이에 유의성 있는 차이는 없었다. 육안적 소견은 생존동물 모두에 약물에 기인한 내부장기의 이상이 관찰되지 않았다. 유전독성시험 : 마우스 골수세포를 이용한 소핵시험에서 약물 투여에 의한 어떠한 독성의 징후도 관찰되지 않았다. 포유류 배양세포를 이용한 염색체이상 시험에서 모든 농도에서 염색체 이상을 가진 세포의 출현빈도가 3% 이하로서 G009는 CHL세포에 대하여 염색체 이상유발성이 없었다. 살모넬라균을 이용한 복귀돌연변이 시험에서 투여군은 음성대조와 같은 정도 또는 그 이하의 복귀변이 집락수를 나타내었다.

• The Journal of Korean Academy of Prosthodontics
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• v.62 no.2
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• pp.95-103
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• 2024

Purpose. With the advancement of digital technology, 3D printing is being utilized in the fabrication of denture base. Nevertheless, increasing microbial adhesion to the surface of denture base has been reported as the disadvantage of 3D-printed denture base. The purpose of this study is to investigate the antifungal properties and flexural strength of 3D-printed denture base resin according to the different contents of titanium dioxide nanoparticles. Materials and methods. Titanium dioxide nanoparticles were mixed with the 3D printing resin at the ratios of 0.5, 1, 1.5, and 2 wt%. Twenty specimens per each group were printed in the form of cylindrical shape (diameter: 20 mm, height: 3 mm) to evaluate antifungal properties. Ten specimens from each group underwent polishing using autogrinder, while the remaining ten specimens did not. Candida albicans in hyphae form was inoculated onto each specimen, optical density and colony-forming unit were analyzed. The surface of the specimen was observed using scanning electron microscopy. To evaluate the flexural strength, twenty specimens per each group were 3D printed in the form of rectangular prism shape (length: 64 mm, height: 10 mm, width: 3 mm) and three-point bending tests were conducted using universal testing machine according to ISO 20795-1. Results. Colony-forming unit of C.albicans and optical density of culture medium showed no difference between non-polished groups, but decreased in the polished groups at concentration of 1, 1.5, 2 wt% titanium dioxide nanoparticles. Flexural strength increased with titanium dioxide nanoparticle at concentration of 0.5, 1, 1.5 wt%, but decreased at 2 wt% compared to 1.5 wt%. Conclusion. When 1.5 wt% of titanium dioxide nanoparticles were added to the 3D-printed denture base resin with polishing, antifungal properties were increased.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.6
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• pp.909-915
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• 2014

This study was carried out to evaluate the genotoxicity of imported oranges irradiated with ionizing energy (0.5 and 1 kGy). In bacterial reversion assays with Salmonella Typhimurium TA98, TA100, TA1535, and TA1537, imported oranges irradiated with ionizing energy (0.5 and 1 kGy) showed no significant increase in the number of revertant colonies in both the absence and presence of the S9 metabolic activation system. In chromosomal aberration tests with Chinese hamster ovary (CHO) cells, imported oranges irradiated with ionizing energy (0.5 and 1 kGy) showed no increase in the frequency of chromosomal aberrations. In in vivo mouse micronucleus assay, imported oranges irradiated with ionizing energy (0.5 and 1 kGy) showed no increase in the frequency of polychromatic erythrocytes with micronucleus. These results indicate that imported oranges irradiated with ionizing energy (0.5 and 1 kGy) showed no genotoxic effects under these experimental conditions.

• Food Science and Preservation
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• v.13 no.4
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• pp.524-529
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• 2006

Gamma irradiation at 30 kGy was applied to cereal powders to evaluate their possible genotoxicity. The genotoxicity of 30 kGy-irradiated cereal powders was evaluated by Salmonella typhimurium reversion assay, chromosomal aberration test and in vivo micronucleus assay. The result were negative in the bacterial reversion assay with S. typhimurium TA98, IA100, TA1535 and TA1537. No mutagenicity was detected in the assay with and without metabolic activation. In chromosomal aberration tests with CHL cells and in vivo mouse micronucleus assay, no significant difference in the incidences of chromosomal aberration and micronuclei was observed between non-irradiated and 30 kGy-irradiated cereal powders. These result indicate that cereal powders irradiated at 30 kGy did not show any genotoxic effect under these experimental conditions.

• Korean Journal of Food Science and Technology
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• v.30 no.4
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• pp.775-780
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• 1998

Gamma irradiation at 5 kGy was applied to beefs for evaluation of their possible genotoxicity and acute oral toxicity. The genotoxicity of 5 kGy irradiated beef was evaluated by Salmonella typhimurium reversion assay and in vivo micronucleus assay using mouse bone marrow cells. The results were negative in the bacterial reversion assay with S. typhimurium TA98, TA100, TA1535, TA1537. Clastogenic effects were not shown in vivo mouse micronucleus assay at 5 kGy dose tested. In an acute toxicity test, 5 kGy-irradiated beef was administrated orally at a dose level of 313 to 5,000 mg/kg, and then number of deaths, clinical signs, body weights, and pathological examinations were examined daily for 14 days post-administration. The results indicate that 5 kGy irradiated beef did not show any toxic effect on mice and oral $LD_{50}$ value was over 5,000 mg/kg on ICR mice.