• Journal of the Society of Cosmetic Scientists of Korea
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• v.32 no.1 s.55
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• pp.53-58
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• 2006

Agrimonia pilosa Ledeb. is a perennial plant, which naturally habitats in whole area of Korea, and where it is popularly used for the traditional remedies. In the present study, A. pilosa Ledeb. extract was prepared to determine the anti-acne effects and application possibility as a cosmetic resource. A pilosa Ledeb. was extracted with methanol and its anti-acne effect against Propionibacterium acnes was investigated via minimum inhibitory concentration (MIC) and paper disk diffusion method. The MIC of A. pilosa Ledeb. extract and triclosan was 0.05 mg/mL and 0.04 mg/mL, respectively. This implies that A. pilosa Ledeb. extract nay be an efficient anti-acne ingredient for cosmetics, considering that it is a crude extract. The paper disk diffusion assay showed that its anti-acne effect was similar to that of triclosan. Furthermore, A. pilosa Ledeb. extract effectively inhibited the growth of several aerobic microorganisms including Staphylococcus aureus. Finally, we examine the stability of the extract to temperature and pH. The extract was very stable to high temperatures ($70{\sim}121^{\circ}C$) and to pH ($pH 2{\sim}11$), suggesting its utilization for cosmetics.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.2
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• pp.55.1-55.1
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• 2016

We have developed a module for the dust continuum radiative transfer calculation as part of "Packages of Unified modeling for Radiative transfer, gas Energetics, and Chemistry (PUREC)". PUREC will be applied to interprete observations of protoplanetary disks. When a disk is under the hydrostatic equilibrium condition, the dust temperature and the vertical density structure should be calculated simultaneously. This module calculates the dust temperature by using the method of mean intensity (Lucy et al. 1999). In the very optically thick mid-palne, the Monte-carlo method is not efficient, thus, we apply "modified random walk" and "Partial Diffusion Approximation" to the module. The module has been verified by bechmark tests.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.6
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• pp.1509-1513
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• 2003

Antifungal activities of the extracts from 26 medicinal plants were investigated utilizing paper-disk diffusion method and (1,3)β-glucan synthase inhibitory assay. (1,3)β-glucan synthase is considered as valuable target in the development of antifungal agents. Among the screened extracts, the ethyl acetate extract of Equisetum arvense, the ethyl acetate extract of Polygonum aviculare, the butanol extract of Crataegus pinnatifida and the n-hexane extract of Saussurea lappa showed significant antifungal activities on Candida albacans in both disk diffusion and enzyme assays.

• Korean Journal of Clinical Laboratory Science
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• v.38 no.1
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• pp.38-44
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• 2006

A simple and easy modification of AST by disk diffusion was tested for the detection of induced clindamycin resistant Staphylococci and their antimicrobial susceptibility at the same time. The incidence of inducible clindamycin resistant staphylococci in blood culture and their MIC characterization at Seoul National University Hospital was analyzed by an AST contained disk approximation test (D-zone test) and Etest, respectively. Of the total 309 staphylococcal isolates, 139 (45%) isolates presented constitutive resistance to ERY and CLI (ERY-R, CLI-R phenotype), and 59 were ERY-I/R and CLI-S phenotypes. Of the 59 isolates, 19 (32%) isolates were inducible resistant to CLI. The incidence was higher in S. aureus (66.7%) than coagulase-negative staphylococci (CNS, 26.0%). Especially, methicillin-resistant staphylococci (MRSA, 100%; MRCNS, 45.5%) presented higher inducibility than methicillin susceptible (MSSA, 50%; MSCNS, 20%). For most of the inducible clindamycin resistant staphylococci (15 of 19 isolates), their ERY MIC were high (>$128_{\mu}g/mL$) and were methicillin resistant. The remaining 4 isolates were methicillin susceptible and their ERY MIC were of intermediate concentrations ($1-4_{\mu}g/mL$). We concluded that suscetibility testing of staphylococci, especially methicillin resistant, should include the D-zone test.

• Journal of Surface Science and Engineering
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• v.27 no.4
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• pp.223-233
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• 1994

It is well known that compositionally modulated Cu-Ni alloy can be produced by an electrochemical method in Ni sulfate solution containing trace amount of Cu. a mathematical model is presented to describe the current distribution and weight percent of Cu in Ni layer on the rotating disk electrode. The model includes convective-diffusion equation, the Laplace's equation and various overpotentials, and is solved numerically. The thickness of Cu layer is almost uniform whereas the thickness of Ni layer as well as the Ni/Cu weight ratio are increased approaching to the edge of the disk. These results agree well with the experimental values. The ohmic potential drop is suggested as a major cause of a nonuniformity in Ni layer. The optimum plating condition for the fabrication of susperlattice is proposed based on the results of this study.

• Microbiology and Biotechnology Letters
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• v.39 no.4
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• pp.387-389
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• 2011

A previous study of ours indicated that Citrus auranifoli oil possesses antifungal activity against Malassezia furfur and Malassezia pachydermatis. In this study, we evaluated the anti-M. furfur and M. pachydermatis activities of limonene, which is a major component of C. aurantifolia oil, using the disk diffusion method. We also examined cytotoxicity against human normal epithelial (Beas-2B) cells using the cytopathic effect reduction (CPE) method. The results revealed that the minimum fungicidal concentration (MFC) value of limonene is lower than the value for itraconazole. The MFC value of limonene was seen to be 7.81 ${\mu}g$/mL against M. furfur and 3.90 ${\mu}g$/mL against M. pachydermatis. MFC values of itraconazole against M. furfur and M. pachydermatis were 62.50 ${\mu}g$/mL and 31.25 ${\mu}g$/mL, respectively. In addition, it was noted that limonene was not toxic to Beas-2B cells with normal morphology at a concentration of 100 ${\mu}g$/mL. However, itraconazole exhibited weak toxicity at the same concentration. Therefore, our results indicate that limonene could potentially be effective at controlling M. furfur and M. pachydermatis infections with no cytotoxicity.

• Nutrition Research and Practice
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• v.6 no.3
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• pp.187-194
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• 2012

In this study, the antibacterial effect was evaluated to determine the benefits of high speed drying (HSD) and far-infrared radiation drying (FIR) compared to the freeze drying (FD) method. Citrus press-cakes (CPCs) are released as a by-product in the citrus processing industry. Previous studies have shown that the HSD and FIR drying methods are much more economical for drying time and mass drying than those of FD, even though FD is the most qualified drying method. The disk diffusion assay was conducted, and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined with methanol extracts of the dried CPCs against 11 fish and five food-related pathogenic bacteria. The disk diffusion results indicated that the CPCs dried by HSD, FIR, and FD prevented growth of all tested bacteria almost identically. The MIC and MBC results showed a range from 0.5-8.0 mg/mL and 1.0-16.0 mg/mL respectively. Scanning electron microscopy indicated that the extracts changed the morphology of the bacteria cell wall, leading to destruction. These results suggest that CPCs dried by HSD and FIR showed strong antibacterial activity against pathogenic bacteria and are more useful drying methods than that of the classic FD method in CPCs utilization.

• Journal of Korean Academy of Oral Health
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• v.42 no.4
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• pp.210-215
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• 2018

Objectives: The main objectives of this study were to verify the antibacterial activity of two essential oils, lavender and peppermint, against dental caries and to review their synergistic effect when used in combination. Our results provide basic data for the evaluation of the use of these two substances towards the prevention and cure of dental caries. Methods: The sample solutions of lavender and peppermint oils were prepared in three different concentrations (30%, 50%, and 70% (v/v)) by diluting them with third-distilled water and Tween 20. Streptococcus mutans was selected as the bacterial species for testing. The disk diffusion method was used to measure the antibacterial activity of the sample solutions. For generating growth curves and measuring the number of clusters of the bacterial, the liquid medium-dilution method was used; the absorbance of the medium was measured at 600 nm after 3, 6, 12 and 24 hours. Results: When the antibacterial activity of the oils was tested via the disk diffusion method, the activity improved with increasing concentrations of all the sample solutions of peppermint, lavender, and the blend, but there was no significant difference between them with respect to the type of oil. In the growth curves of S. mutans, growth inhibition was observed after 12 hours. The inhibitory effect of 30% lavender oil on growth was 64.9% and 80.1% after 12 and 24 hours of treatment, respectively whereas that of peppermint oil was 71.3% and 80.1% after 12 and 24 hours of treatment, respectively. The inhibitory effect of the blended oil was 71.9% and 81.0% after 12 and 24 hours of treatment, respectively. Conclusions: Further research is still required in order to determine the efficacy of lavender and peppermint oils, as well as other essential oils, for wider use in preventing dental caries.

• Journal of The Korean Society of Integrative Medicine
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• v.11 no.2
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• pp.149-157
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• 2023

Purpose : In this study, to prove the antibacterial effect of Disocorea batatas, which is widely used for food, and to confirm the growth inhibitory effect, the antibacterial activity against L. gasseri, S. mutans, and P. gingivalis was verified. Based on this, it is intended to verify the utility as a preventive and therapeutic composition for dental caries and periodontal disease. Methods : RAW 264.7 cells were used to verify the cell survival rate and NO (Nitric Oxide) inhibitory effect on Disocorea batatas ethanol extract (DBEE). In order to verify the antibacterial effect against L. gasseri, S. mutans, and P. gingivalis, concentrations of 125, 250, and 500 ㎎/㎖ of DBEE were used and measured by the disk diffusion method. In order to confirm the growth inhibitory effect, the absorbance was measured at 600 ㎚ at 3, 6, 12, 18, and 24 hours using the liquid medium dilution method, and the growth inhibitory effect was measured compared to the control group. Results : The cell viability for DBEE was 91 % at 50 ㎎/㎖, and there was no cytotoxicity. The NO production inhibitory effect was shown from 10 ㎍/ml, and the higher the concentration, the greater the inhibitory effect. As for the antimicrobial effect using the disk diffusion method, the higher the concentration, the higher the antibacterial effect. At 125 ㎎/㎖ and 250 ㎎/㎖, S. mutans and L. gasseri showed high antimicrobial activity, and at 500 ㎎/㎖, the antibacterial effect was higher in L. gasseri. The growth inhibitory effect in DBEE was concentration-dependent as the higher the concentration, the higher the growth inhibitory effect, and all of them began to show growth inhibitory effects from 6 hours. Conclusion : Considering that it is widely used as an edible and medicinal material, Disocorea batatas has shown the potential to be used as a substance to prevent and alleviate dental caries and periodontal diseases, and it is believed that further research can be applied to oral health care products.

• Advances in Traditional Medicine
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• v.6 no.4
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• pp.306-311
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• 2006

This communication emphasized upon the sensitivity of the crude extracts of clerodendrum inerme against some of the human pathogenic bacteria. Five plant extracts (Petrol, Benzene, Methanol, Ethly acetate and Aqueous) under six different concentrations(500 ${\mu}g/ml$, 1 mg/ml, 2 mg/ml, 5 mg/ml, 10 mg/ml and 15 mg/ml) were tested by disk diffusion method. Methanol, Ethyl acetate and Aqueous extracts of the plant showed significant inhibition against fifteen of the eighteen bacteria tested. No earlier report on antibacterial activity of this taxon could be found in literature.