• 대한화장품학회지
• /
• 제32권1호
• /
• pp.53-58
• /
• 2006

본 연구는 우리나라의 야산이나 길가, 들판 등에 흔히 자라는 여러해살이 풀이며, 오래 전부터 민간요법 및 한방에 유용 한 약재로 사용되어 지고 있는 선학초(Agrimonia pilosa Ledeb.)를 이용하여 여드름 유발균에 대한 항균활성을 평가하고, 이를 토대로 항여드름 관련 화장품 소재를 개발하는데 그 목적이 있다. 선학초를 methanol로 추출한 후, 이 추출물을 여드름 유발균주인 P. acne를 이용하여 minimum inhibitory concentration (MIC) 및 paper disk diffusion assay로 항균 효과를 측정하였으며, 추출물에 대한 온도 및 pH 변화에 따른 안정성을 평가하였다. 추출물을 이용하여 P. acne에 대한 MIC 값은 0.005 mg/mL로 측정되었으며, 이는 대조군으로 사용한 항생제인 triclosan의 MIC 값(0.004 mg/mL)과 비교했을 때 시료가 선학초 전초에 대한 crude extract임을 고려하면 매우 항균활성이 높은 것으로 평가되었다. 추출물에 대한 paper disk diffusion assay를 수행한 결과, 대조군으로 사용한 triclosan 처럼 높은 활성을 나타내는 것으로 측정되었으며, Staphylococcus aureus를 비롯한 여러 종의 호기성 균주에도 선학초추출물은 항균활성이 우수한 것으로 평가되었다. 선학초 추출물의 온도, pH 안정성을 평가한 결과, 70, 80, 90, 100, $121^{\circ}C$ 등 다양한 온도 조건과 $pH 2{\sim}pH 11$의 변화에 있어서도 그 효능이 변하지 않고 안정된 상태로 유지되는 것으로 관찰되었다.

• 천문학회보
• /
• 제41권2호
• /
• pp.55.1-55.1
• /
• 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.

• 동의생리병리학회지
• /
• 제17권6호
• /
• pp.1509-1513
• /
• 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.

• 대한임상검사과학회지
• /
• 제38권1호
• /
• pp.38-44
• /
• 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.

• 한국표면공학회지
• /
• 제27권4호
• /
• pp.223-233
• /
• 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.

• 한국미생물·생명공학회지
• /
• 제39권4호
• /
• pp.387-389
• /
• 2011

우리의 이전의 연구에서 Citrus auranifoli 오일은 Malassezia furfur와 Malassezia pachydermatis에 대해 항곰팡이 활성을 나타낸다는 것을 보여주었다. 본 연구에서 Citrus auranifoli 오일의 주요 성분인 리모넨(limonene)의 M. furfur와 M. pachydermatis에 대한 저해효과를 디크스 확산 방법(disk diffusion method)에 의해 측정하였고, Beas-2B 세포에 대한 세포독성을 cytopathic effect reduction 방법에 의해 측정하였다. Limonene의 최소곰팡이저해농도(minimum fungicidal concentration)는 양성대조구인 itraconazole보다 더 낮았고, 100 ${\mu}g$/mL의 농도에서 Beas-2B cells에 대한 세포독성을 나타내지 않았다. 그러나 itraconazole은 같은 농도에서 약한 세포독성을 나타내었다. 그러므로, 우리의 결과에서 limonene는 비세포독성과 함께 M. furfur and M. pachydermatis의 성장저해를 하는데 효과적이라는 것을 보여준다.

• Nutrition Research and Practice
• /
• 제6권3호
• /
• pp.187-194
• /
• 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
• /
• 제42권4호
• /
• pp.210-215
• /
• 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.

• 대한통합의학회지
• /
• 제11권2호
• /
• pp.149-157
• /
• 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
• /
• 제6권4호
• /
• pp.306-311
• /
• 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.