• Natural Product Sciences
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• 제10권6호
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• pp.325-329
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• 2004

The composition of essential oil from O. javanica was analyzed by gas chromatography-mass spectrometry. Using the broth dilution method and disk diffusion test, anti-microbial activities of the oil fraction and its main components were evaluated against various antibiotic-susceptible and resistant strains of pathogenic microorganisms. As a result of GC-MS analysis, 57 compounds, including ${\alpha}-terpinolene$ (28.1%), dl-limonene (16.0%), ${\gamma}-terpinene$ (10.3%), ${\beta}-pinene$ (9.7%) and ${\alpha}-pinene$ (6.0%) were identified in the essential oil fraction. The essential oil fraction of O. javanica and its main components exhibited significant inhibitory activities, particularly against Candida albicans (antibiotic-susceptible strains) and Streptococcus pneumoniae (antibiotic- susceptible and resistant strains). The main components of the O. javanica oil fraction displayed different patterns of activity against the three tested Candida species as exemplified by the differential minimum inhibiting concentration (MIC) values. The disk diffusion test showed that the activities were dose dependent.

• 융합신호처리학회논문지
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• 제8권4호
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• pp.249-254
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• 2007

본 논문은 실명(loss of eyesight)의 원인 중 하나인 녹내장의 진행과 진단 등의 의료 정보제공을 목적으로 양방향 곡선 전개 방식을 이용하여 망막 영상에서 시신경 원판(optic disk)의 경계를 검출하는 방법을 제안한다. 정확한 경계 검출을 위하여 PDE 기반의 Image inpainting 방법으로 시신경 원판 위를 지나는 혈관을 제거하고 전처리 과정에서 발생하는 잡음제거와 경계의 보존을 위해 비등방성 필터링(anisotropic filtering)을 행한다. 혈관이 제거된 망막 영상에서 시신경 원판의 경계 검출은 초기 곡선에 강인한 양방향 곡선 방식으로 검출한다. 실험결과, 제안한 방법이 전체영상의 블러링 현상뿐만 아니라 시신경 원판 경계의 블러링 현상을 줄일 수 있었고, 기존의 방법에 비하여 정확한 경계를 검출할 수 있었다.

• Journal of Periodontal and Implant Science
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• 제26권1호
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• pp.202-215
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• 1996

The purpose of this study was to an in estigate the antibiotic susceptibiliity of Actinoobacillus actinomycetemcomitans isolated from the subgingival plaque to adult periodontitis. Seven bacterial strains were tested for their susceptibility to 10 antimicrobial agents under disk diffusion method and broth dilution methold, Seven patients with deep pocket(6mm) were selected for this study. They had not taken antibiotics for 6 months and no history of dental treatment for 6 months and no history of dental treatment for 6 months before this study. The results were as follows : 1. For the antibiotic disk diffusion method, seven A. actinimycetemcomitans were tested with 10 antimicrobial agents which comprised penicillin, gentamycin, clindamycin, lincomycin, ampicillin, erythromycin, tetracycline, amikacin, chloramphenicol, and vancomycin. The sensitive antibiotics were tetracycline, vancomycin, and chloramphenicol and the resistant antibiotics were clindamycin, and lincomycin. The other antimicrobial agents were less active. 2. From the study of determination on the minimal inhibitory concentration(MIC) by broth dilution method, the MIC of tetracycline to seven strains of the A. actinomycetemcomitans was $0.5-1.0{\mu}g/ml$, that of clindamycin was $32{\mu}g/ml$. These data suggest that tetracycline may be valuable drugs in the elimination of A. actinimycetemcomitans from the patients with adult periodontitis

• 대한화장품학회지
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• 제25권3호
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• pp.87-99
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• 1999

천연 물질로 지용성인 뉴질랜드산 차나무 정유(Manuka oil), 그 구성 성분인 $\alpha$-pinene, Oxy’less clear, 수용성인 자몽 종자 추출물(Citrex) 및 그 구성성분인 R-limonene의 항균력 을 측정 평가하여 항균력을 보다 향상시키고 광범위하게 사용할 수 있는 방부제의 처방을 제안하였다. 항균력 측정에는 disk diffusion법이 사용되었으며, 균주로는 그람 음성균인 Escherichia coli와 그람 양성균인 Staphylococcus aureus을 사용하였다. Manuka oil과 $\alpha$-pinene은 항균력이 10${\mu}\ell$/paper disk일 때에는 큰 차이가 없었으나 2${\mu}\ell$/paper disk이하의 소량의 시료에서는 Manuka oil이 $\alpha$-pinene에 비해 월등하게 우수하였다. Citrex가 R-limonene보다 두 균주에 대하여 항균력이 모든 농도에서 우수한 성능을 보였다 Oxy’less clear은 두 균주에 대하여 모든 농도에서 파라벤류 propyl para hydroxybenzoate(PPHB)나 R-limonene보다는 항균효과가 우수하며 $\alpha$-pinene과는 비슷하게 나타났고, Manuka oil과 Citrex보다 약간 낮게 나타났다. 이상을 종합해 본 결과 Manuka oil과 Citrex가 다른 물질들에 비해 항균력이 가장 우수한 것으로 나타났다. 항균력이 우수한 지용성 물질 Manuka oil과 확산도가 큰 수용성 물질 Citrex를 적절히 혼합하여 항균력을 향상시키고 광범위하게 사용할 수 있는 이상적인 혼합비(Manuka oil : Citrex)를 구하였는데 Escherichia coli에 대해서는 75 : 25이었고 Staphylococcusureus에 대해서는 25 : 75 이었다.

• Food Science and Biotechnology
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• 제15권5호
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• pp.817-819
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• 2006

8-Quinolinol and other quinolinol derivatives were evaluated with regard to their growth-inhibitory effects against intestinal bacteria, using the paper disk-agar diffusion method. The observed growth responses varied according to the chemicals and dosages used, as well as the bacterial species tested. 8-Quinolinol showed a significant inhibitory effect against Clostridium difficile, C. perfringens, and Escherichia coli, at 5, 2, 1, and 0.5 mg/disk, and also exhibited a very strong inhibitory effect at 0.25 mg/disk. At low concentrations, 8-quinolinol had strong inhibitory effects against C. perfringens at 0.1 and 0.05 mg/disk; 8-quinolinol also manifested a moderate inhibitory effect against C. perfringens at 0.025 mg/disk. Furthermore, 8-quinolinol revealed moderate and weak growth inhibition against C. difficile and E. coli at concentrations of 0.1 and 0.05 mg/disk, respectively, but 2-quinolinol, 4-quinolinol, and 6-quinolinol evidenced no growth inhibition against B. bifidum, B. longum, C. difficile, C. perfringens, E. coli, or L. casei. The inhibitory effects of 8-quinolinol against C. difficile, C. perfringens, and E. coli lead to its consideration as a possible therapeutic modality for the treatment of diseases associated with harmful intestinal bacteria.

• 동의생리병리학회지
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• 제18권5호
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• pp.1490-1493
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• 2004

We investigated antifungal and antioxidant activity of Equsetum arvense L. The sterile stems of Equsetum arvense L. were extracted with methanol and then fractionated with n-hexane, ethyl acetate, butanol, and water. And their antifungal activities were determined by using paper disk diffusion method and (1. 3)β-glucan synthase inhibitory activity assay, and antioxidant activities were determined by using DPPH method. The ethyl acetate fraction showed antifungal activity on Candidas albacans in both disk diffusion and enzyme assays. This also showed antioxidant activity in DPPH assay. Further fractionation with ethyl acetate fraction was performed to obtain effective fractions. 4, 5, 6 and 7 fractions showed the significant antifungal antivities, and, 4 and 5 fractions showed the strongest antioxidative activity.

• Journal of the Korean Wood Science and Technology
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• 제22권2호
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• pp.61-70
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• 1994

This study was executed to find the applicability of press drying of tree disk by investigating the shrinkage and drying defect and to form appropriate model by comparing the actual moisture content(MC) and internal temperature in respect of drying time with calculated values based computer simulation to which was applied finite difference method. In press drying disk, heating period, constant drying rate period maintained plateau temperature at 100$^{\circ}C$ and falling drying rate period were significantly distinguished. Actual MC and internal temperature were analogous to those calculated at comparing points. Heat transfer model formed by Fourier's law using specific heat of moist wood and conduction coefficient considering fractional volume of each element of wood cell wall, bound water, free water and air showed applicability as basic data to developing heat expansion, shrinkage and drying stress during press drying. Also mass transfer model formed by Fick's diffusion law using water vapor diffusion coefficient showed applicability. Longitudinal shrinkage was developed by pressure of hot press and tangential shrinkage was restrained by hygrothermal recovery. The heart check, surface check and ring failure were occurred differently in species, but V-shaped crack didn't develop.

• 약학회지
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• 제34권3호
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• pp.161-165
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• 1990

An automated, simple, and reliable method was developed for determining in vitro drug release rate from transdermal delivery dosage forms. The patch is held in position in the heating block by sandwiching it between the middle plate and the bottom plate of diffusion cell. The dissolution profile of the commercially available transdermal scopolamine patch was determined over a 72-h period, and the results were compared with those obtained with other methods; paddle-over-disk method, reciprocating method, and diffusion cell method. It was demonstrated that the flow-through method is equivalent in terms of release rate profile and accumulated released drug amount over the lifetime of the dosage form tested. Also this method is simple, reliable and reproducible. Therefore, this technique can be used in a quality control for assuring product uniformity.

• 치위생과학회지
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• 제18권3호
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• pp.147-154
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• 2018

This study aimed to evaluate the antimicrobial effects of Acanthopanax sessiliflorum fruit (ASF; Ogaza) extracts on Streptococcus mutans and Streptococcus sobrinus, which are agents that cause dental caries, and on Streptococcus mitis and Streptococcus salivarius, the microbial flora of the oral cavity. The ASF extracts obtained using 70% ethanol were fractionated in the order of ethyl acetate and n-Butanol, concentrated under reduced pressure, and lyophilized to give powdery solvent extracts. The antimicrobial activity of ASF extracts from each solvent was examined using the disk diffusion method. As a result, only those extracts obtained using an ethyl acetate solvent showed antimicrobial activity. These extracts were selected, and the minimum inhibitory concentration was measured by disk diffusion method at various extract concentrations. Results showed a minimum inhibitory concentration of 32 mg/ml. The viable cell count was measured to confirm the minimum bactericidal concentration. Results showed a minimum bactericidal concentration of 64 mg/ml. In the cytotoxicity test using normal human dermal fibroblast cells, the absorbance value of the test group was similar to that of the control group at 0.64, 1.28, and 6.4 mg/ml. The bacteria and their colonies were examined using a scanning electron microscope. Boundaries between the antimicrobial activity region and non-antimicrobial activity region were observed around the paper disk, which was immersed in the extract with 32 mg/ml concentration. Bacterial colonization was not observed in the area with antimicrobial activity. This finding suggests that ASF extracts can inhibit the growth of some microorganisms in the oral cavity, in addition to the effects of these extracts known to date. In particular, ASF extracts may be used as a preparation for preventing dental caries by adding the extract to the toothpaste or oral mouthwash.

• 대한화장품학회지
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• 제32권3호
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• pp.201-208
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• 2006

본 연구는 예로부터 민간요법 및 한방에 유용한 약재로 사용되어지고 있는 관중(Dryopteris crassirhizoma Nakai)을 이용하여 Propionibacterium acnes에 대한 항균활성을 평가하고, 이를 토대로 여드름 억제 및 치료에 관련된 화장품 소재를 개발하는데 그 목적이 있다. P. acnes에 대한 관중 crude 추출물 및 헥산분획물의 minimum inhibitory concentration (MIC) 및 paper disk diffusion assay로 항균 효과를 측정하였으며, 추출물에 대한 온도 및 pH 변화에 따른 안정성을 평가하였다 추출물을 이용한 P. acnes에 대한 MIC 값은 관중 crude 추출물은 0.008 mg/mL, 헥산추출물은 0.001 mg/mL로 측정되었으며, 이는 대조군으로 사용한 항생제인 triclosan의 MIC 값(0.004 mg/mL)과 비교했을 때 시료가 관중 crude 추출물 및 헥산 분획물임을 고려하면 매우 항균활성이 높은 것으로 평가되었다. 추출물에 대한 paper disk diffusion assay를 수행한 결과, 대조군으로 사용한 triclosan과 대비, 높은 활성을 나타내는 것으로 측정되었으며, HaCaT 세포에 대한 독성은 $20{\mu}g/mL$ 이하의 농도에서는 나타나지 않았다. 관중추출물의 온도, pH 안정성을 평가한 결과, 25, 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.