• 천문학회보
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• 제45권1호
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• pp.70.3-70.3
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• 2020

Previous numerical simulations on planet-disk interactions revealed a lot of interesting phenomena including the planetary migration and the formation of many sub-structures inside the disks. However, these simulations were limited to an isothermal or adiabatic equation of state which does not account for various heating and cooling processes in the disks. Recent studies showed that the behavior of the planet-disk interaction can be significantly influenced by the disk thermodynamics. We develop a radiative diffusion module based on the two-temperature flux-limited diffusion approximation accounting for viscous heating and the accretion feedback. In this presentation, we describe our radiative diffusion solver, present some test results, and discuss potential applications of the module to planet-disk interactions,

• Journal of Microbiology and Biotechnology
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• 제9권3호
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• pp.328-333
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• 1999

Susceptibility of 61 strains of Helicobacter pylori to metronidazole was examined by both the disk diffusion method using a cut-off of 15㎜ for resistance and the E test with a cut-off of 8㎎/l. The MIC/sub 50/ and MIC/sub 90/ by the E test were 2 ㎎/l and 256㎎/l, respectively. Metronidazole resistance was found in 22 (36％) out of the 61 H. pylori strains by the E test and in three additional strains by the disk diffusion method. Amongst the latter three isolates, the MICs by the E test were 4 ㎎/l, 6㎎/l, and 6㎎/l, respectively. These figures are one log₂ or half log₂ dilution lower than the cut-off of 8㎎/l recommended as resistance for the E test. All 22 metronidazole resistant H. pylori isolates by the E test that were subjected to random amplified polymorphic DNA (RAPD) fingerprinting showed different DNA fingerprints. Interestingly, >90％ of resistant isolates possess two common DNA bands of 0.4 and 0.9 kb. This study demonstrates that the results of the disk diffusion method for testing H. pylori susceptibility to metronidazole correlates well with that of the E test. The criteria for interpretation need to be internationally standardized so that the results from different centers can be compared.

• 대한화장품학회지
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• 제24권1호
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• pp.100-112
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• 1998

향 비듬 샴푸에 대한 비중이 증가되는 현 샴푸시장에서 향 비듬력을 측정할 수 있는 간단한 in vitro 실험법의 요구가 증대되고 있다. 기존의 향 비듬력의 측정을 위하여 사용되고 있는 방법으로는 Pityrosporum ovale에 대한 MIC test와 halo test가 널리 쓰이고 있으나, Pityrosporum 배지의 자체 탁도 때문에 균의 성장 여부를 육안으로 관찰하기 어렵고, 종이 디스크와 두피와의 차이에 의하여 실제 사용과 효과가 다르다는 단점이 있었다. 저자들은 임상 실험을 거치기 전 간단히 향 비듬력을 측정할 수 있는 in vitro 방법으로 skin disk diffusion method를 개발하였다. SDDM에서는 종이 디스크 대신 기니픽의 피부 조직을 사용하고, 향 비듬 제제의 처리 후 세척 단계를 포함시켜 실제 사용과의 차이를 줄였다. SDDM의 유용성을 확인하기 위하여 향 비듬 제제로 2.0% ketoconazole, 분산된 상태의 zinc pyrithion, 분자화 기술로 활성을 높인 ZPT에 대해 기존의 in vitro 시험법과 함께 향 비듬력을 측정하였다. 결과는 SDDM 시험에서만 20% ketoconazole 제제와 분자화된 0.5% ZPT제제의 억제대가 비슷한 것으로 나타나 임상 시험에서 두 제제 모두 비듬에 대해 개선 효과가 있었으며 향 비듬 효과에 차이가 없다는 결과와 일치하였다. 본 시험의 결과로 SDDM이 향 비듬 샴푸와 같은 wash-off 제품의 효능 측정에 간단하고 효과적인 적절한 in vitro 시험법으로 생각되어 SDDM 시험과 임상 시험결과를 소개한다.

• Elastomers and Composites
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• 제56권4호
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• pp.254-263
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• 2021

In this study, chitosan obtained after varying extents of deacetylation (i.e., 10%, 30%, and 47%) was employed to introduce antibacterial properties to chitin. The deacetylation reaction completion, wherein the amino group content of chitin was reduced, was ascertained from the FT-IR and NMR analyses. The 47%-deacetylated chitosan exhibited superior antibacterial properties against Bacillus in a disk diffusion test. To further improve these properties, chitosan derivatives were grafted by acrylic acid and acrylamide. The varying concentrations of carboxyl groups, primary amines, and -CH₂-CH₂- with increasing acrylic acid and acrylamide contents were determined by FT-IR and NMR analyses. The enhanced antibacterial properties of the chitosan derivatives, owing to the increased acrylic acid and acrylamide contents, were revealed by the disk diffusion test. In particular, the derivatives with 1.3% acrylic acid and acrylamide showed the highest antibacterial activity, the bacterial reduction rate against Staphylococcus aureus and Escherichia coli being 99.9%, as observed through the ASTM E2149 standard test.

• 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.

• Restorative Dentistry and Endodontics
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• 제19권2호
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• pp.568-584
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• 1994

Bacteria have been regarded as major etiolgic factors in root canal infections. Infected root canal flora from thirteen patients who had visited to conservative department of Wonkwang dental hospital were cultured on blood agar plates. Cultued microorganisms were isolated and identified with Gram stain and biochemical tests using Vitek Systems(BioMeriux, MO, USA); Antibiotic susceptibillity was performed with disk diffusion and broth microdilution using Vitek Systems. Gram positive cocci(65 %) were predominant, which were composed of 6 Streptococcus viridans group, 5 Staph. spp., and 4 Enterococcus faecium, in the isolatd 23 strains. Gram negative rods (26 %) were the next common bacteria, which were composed of 5 non - fermentative Gram negative rods, and 1 Enterobacter cloacae. Most strains of S. viridans group and E. faecium were susceptible to antibiotics including penicillin. But strains of Staphylococcus spp. and non - fermentative Gram negative rods showed marked resistance to antibiotics except tetrancyclin and cefotaxime. Most results between disk diffusion and microdilution were all agreed, but the results of non - fermentative Gram negative rods were susceptible to cefotaxime in disk diffusion method but resistant in microdilution.

• 대한임상검사과학회지
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• 제38권1호
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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 Preventive Veterinary Medicine
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• 제42권4호
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• pp.148-156
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• 2018

Clostridium perfringens (C. perfringens) may cause diarrhea and enterotoxemia in adult and young livestock, leading to problems in the production and management of farms. Four hundred fecal samples were collected from 25 goat farms located in Gyeongsangbuk-do Province in the Republic of Korea. Sixteen C. perfringens strains were isolates from fecal samples, and the isolates were identified as type A (n=11) and type D (n=5). Additionally, ${\alpha}$- and ${\varepsilon}$-toxin genes were detected in 16 and 5 strains by PCR, respectively, and the enterotoxin gene was presented in 2 strains. The antibiotic susceptibility test was performed using the disk diffusion method and E-test method. In the disk diffusion method, ampicillin (n=16) and chloramphenicol (n=15) were highly susceptible to 16 C. perfringens isolates. In the E-test method, ampicillin, amoxicillin, amoxicillin/clavulanic acid and meropenem were susceptible to more than 14 of 16 C. perfringens isolates. This study indicates that administration of antibiotics such as ampicillin, amoxicillin/clavulanic acid and meropenem can prevent and treat C. perfringens infections in goats.

• Archives of Pharmacal Research
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• 제25권6호
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• pp.860-864
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• 2002

In this study the composition and antimicrobial properties of essential oils obtained from Origanum onites, Mentha piperita, Juniperus exalsa, Chrysanthemum indicum, Lavandula hybrida, Rosa damascena, Echinophora tenuifolia, Foeniculum vulgare were examined. To evaluate the in vitro antibacterial activities of these eight aromatic extracts; their in vitro antimicrobial activities were determined by disk diffusion testing, according to the NCCLS criteria. Escherichia coli (ATTC 25922), Staphylococcus aureus (ATCC 25923) and Pseudomonas aeruginosa (ATTC 27853 were used as standard test bacterial strains. Origanum onites recorded antimicrobial activity against all test bacteria, and was strongest against Staphylococcus aureus. For Rosa damascena, Mentha piperita and Lavandula hybrida antimicrobial activity was recorded only to Staphylococcus aureus. Juniperus exalsa, and Chrysanthemum indicum exhibited antibacterial activities against both Staphylococcus aureus and Escherichia coli. We also examined the in vitro artimicrobial activities of some components of the essential oils and found some components with antimicrobial activity.

• 대한임상검사과학회지
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• 제50권4호
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• pp.431-437
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• 2018

Acinetobacter baumannii는 광범위한 항생제에 대한 저항성으로 인해 감염된 환자의 사망률이 높아지는 적색 경보 병원체로 분류됩니다. 이 연구에서 다제 내성 A. baumannii(MRAB)의 18가지 임상 분리 균주에 대해 일부 에센셜 오일(티트리, 로즈마리, 라벤더 오일)의 항균 활성을 평가하고자 하였다. Carbapenemase 선별을 위한 Hodge 시험법은 A. baumannii의 20 가지 균주가 모두 imipenem에 내성이 있음을 보여주었습니다. 다제 내성 미생물의 확인은 VITEK 시스템을 통해 수행하였다. 에센셜 오일의 항균 활성은 MRAB에 대한 디스크 확산 방법으로 평가하였다. 디스크 확산 방법에서 tee tree는 라벤더 오일에 비해 억제 크기가 가장 크게 증가했으며, 로즈마리는 항균 효과가 없었다. 티 트리 오일은 가장 일반적인 인간 병원균 및 MRAB 감염의 치료 및 예방을 위한 대체 천연 제품으로 유용할 것으로 보인다. 따라서 이 연구의 결과는 다제 내성 A. baumannii의 항균 효과를 입증했으며, 미래에 천연 에센셜 오일을 사용하는 손 소독제와 같은 항균제로 사용될 것으로 예상됩니다.