• Food Science and Biotechnology
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• v.15 no.2
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• pp.321-323
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• 2006

A combination of thymol and sodium bisulfate was found to be an effective biocidal agent against strains of Burkholderia cepacia and of Xanthomonas maltophilia that were found in the space shuttle water system. Potassium iodide (KI), the biocidal agent used in the past, had a minimum inhibitory concentration (MIC) of 50,000 ppm against the two B. cepacia (541 STS-81 and 1119 STS-91) strains, whereas that of thymol and sodium bisulfate was 2,400 and 950 ppm, which was 21 and 53 times lower than that of KI for B. cepacia, respectively. The MIC value for the combination of thymol and sodium bisulfate was 4 times lower than that for thymol or sodium bisulfate alone against B. cepacia (541 STS-81, 1119 STS-91) or Pseudomonas cepacia (ATCC 31941). The fractional inhibitory concentration (FIC) of the combination of thymol and sodium bisulfate for all organisms tested was less than 0.5, indicating a strong synergistic effect.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.483-483
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• 2000

The Fuzzy Preview Control (FPC) design methodology using I-PD Preview Control (IPC) and Optimal Preview Control (OPC)[6] are discussed in this paper. First we show a new fuzzy controller with single input single output, and build a relationship between it and the I-PD Control proposed by Kitamari, as well as Optimal Control with some specific equations. We also give the stability analysis with Lyapunov theorem. On this way, we can design a Fuzzy I-PD Controller (FIC) very easier and more effective. Then, preview control element design methodology of FCP was given according to IPC and OPC. Third, to make the system more rapidly and more little overshooting, two factors are given to adjust the controller's properties. At last, the performance of FPC is revealed via computer simulation using a nonlinear plant.

• YAKHAK HOEJI
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• v.46 no.3
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• pp.203-207
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• 2002

The antifungal activities of the essential oils from Anthemis nobilis, Ciderus atlantica, Juniperus communis, Lavandula angustifolia, Pelargonium graveolens, Pogestemon patchouli, Rosmarinus officinalis, and Styrax tonkinensis which are recommended for the treatment of microbial infections in aromatherapy and complementary medicines were tested against Candida spp. The activities were measured by broth dilution method and disk diffusion assay. Most of the test oils inhibited growth of Candida albicans, C. utilis and C. tropicalis. Especially, the essential oil from Pelargonium graveolens and its main component, citronellol showed the strongest activity among the herbs except benzoic acid from Styrax tonkinensis which is well-known antimicrobial compound. As a result of checkerboard microtiter test. synergistic effect of citronellol, was shown when the component was combinated with ketoconazole, displaying a fractional inhibiting concentration (FIC) index of 0.37 against C. albicans.

• Bulletin of the Korean Chemical Society
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• v.35 no.1
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• pp.123-128
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• 2014

In this study, we have investigated the flow rate effects of Ag nanoparticle (NP) suspensions on the progress of the cell cycle by using a microfluidic image cytometry (${\mu}FIC$)-based approach. Compared with the conventional "static" exposure conditions, enhancements in G2 phase arrest were observed for the cells under continuously flowing "dynamic" exposure conditions. The "dynamic" exposure conditions, which mimic in vivo systems, induced an enhanced cytotoxicity by accelerating G2 phase arrest and subsequent apoptosis processes. Moreover, we have also shown that the increases in delivered NP dose due to the continuous supply of Ag NPs contributed dominantly to the enhanced cytotoxicity observed under the "dynamic" exposure conditions, while the shear stress caused by these slowly flowing fluids (i.e., flow rates of 6 and $30{\mu}L/h$) had only a minor influence on the observed enhancement in cytotoxicity.

• The Monthly Technology and Standards
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• s.119
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• pp.32-36
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• 2012

한국산업기술시험원은 1966년 4월 국내 정밀기기산업과 전자산업 육성을 위하여 우리정부와 UNESCO(유엔교육과학문화기구)가 공동 설립한 한국정밀기기센터(FIC)로 발족했다. 1989년 10월 한국생산기술연구원 부설 품질평가센터로 개편된 이후 1999년 3월 한국산업기술평가원 부설 산업기술시험원으로 개편되었고, 2006년 11월 한국산업기술시험원(KTL)으로 독립법인화되었다. 현재는 기술혁신 성과물의 시험 평가와 기술개발 등의 효율적 지원을 위한 적합성평가와 관련 R&D를 수행하고 있는 종합 시험 평가기관으로 성장을 계속하고 있다. 남궁민 한국산업기술시험원 원장으로부터 그 동안의 성과와 앞으로의 비전에 대해 들어보았다.

• Archives of Pharmacal Research
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• v.26 no.5
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• pp.389-393
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• 2003

The essential oils from Cedrus atlantica, Styrax tonkinensis, Juniperus communis, Lavandula angustifolia, Melaleuca alternifolia, Pelargonium graveolens, Pogestemon patchouli and Rosmarinus officinalis were analyzed by GC-MS. Antifungal activities of the oils were investigated by disk diffusion assay and the broth dilution method against Aspergillus niger and A. flavus. The effects of geraniol and the essential oil fraction from P. graveolens on the antifungal activity of amphotericin Band ketoconazole were examined using a checkerboard microtiter assay against both Aspergillus fungi. Most of the tested essential oils, with the exception of C. atlantica, J. communis, and P. patchouli, significantly inhibited growth of A. niger and to a lesser extent that of A. fIavus, with MICs (minimal inhibitory concentrations) in the range 0.78-12.5 mg/mL. The essential oil fraction of P. graveolens and its main components, geraniol and citronellol, exhibited additive effects with amphotericin B and with ketoconazole against both Aspergillus species, resulting in fractional inhibitory concentration (FIC) indices ranging from 0.52 to 1.00.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 1997.11a
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• pp.534-541
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• 1997

Isothermal solubilities of nitrogen in clean fire extinguishing agents, such as bromotrifluoromethane (Halon-1301), bromochlorodifluoromethane (Halon-121 t), 1,1,1,2,3,3,3- heptafluoropropane (HFC-227ea), and trifluoroiodomethane (FIC-13I1) were measured in a circulation-type equilibrium apparatus. The temperature range was (293.2 to 313.2) K and the pressure range was (30 to 100) bar. The experimental data were well correlated with the Peng- Robinson equation of state using the Wong and Sandier mixing rules, and the relevant parameters are presented.

• Microbiology and Biotechnology Letters
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• v.47 no.3
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• pp.459-464
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• 2019

This study aimed to identify and characterize the antimicrobial activity of prodigiosin produced by Serratia sp. $PDGS^{120915}$ isolated from stream water in Busan, Korea; the identification was performed using phonological, biochemical, and molecular techniques, including 16S rRNA sequence analysis. Prodigiosin from the bacterial culture was purified by high-performance liquid chromatography (HPLC), and its antimicrobial activity and minimum inhibitory concentrations (MICs) were evaluated against 10 intestinal pathogenic gram-positive and negative bacteria. The results revealed that the isolated prodigiosin exhibited high antimicrobial activity against Listeria monocytogenes, Bacillus cereus, Pseudomonas aeruginosa, Salmonella typhimurium, Staphylococcus aureus, and Vibrio parahaemolyticus; further, the isolated prodigiosin showed minimum inhibitory concentrations (MICs) between $3{\mu}g/ml$ and 30 mg/ml, but they were not active against Bacillus subtilis, Enterococcus faecalis, Klebsiella pneumonia, and Escherichia coli. In conclusion, prodigiosin isolated from Serratia sp. $PDGS^{120915}$ showed high antimicrobial activity against intestinal pathogenic bacteria and has potential applications in the development of new antimicrobial agents.

• The Journal of Korean Obstetrics and Gynecology
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• v.24 no.2
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• pp.1-12
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• 2011

Objectives: The object of this study was to observe the in vitro antibacterial effects of Chungdae-tang aqueous extracts, traditionally used for treating various gynecological diseases including vaginitis in Korea against Gardnerella vaginalis, and combination effects of Chungdae-tang extracts with Clindamycin were also monitored in this study. Methods: Antibacterial activities against Gardnerella vaginalis of Chungdae-tang aqueous extracts were detected using standard agar microdilution methods. In addition, the effects on the bacterial growth curve were also monitored at MIC and MIC${\times}$2 levels. The combination effects of Chungdae-tang aqueous extracts with Clindamycin were observed by Checkerboard microtiter assay, and the effects of bacterial growth curve treated with or Chungdae-tang aqueous extracts MIC+Clindamycin MIC, 1/2MIC and 1/4MIC, respectively. In the present study, Gardnerella vaginalis were incubated under $37^{\circ}C$, 10% $CO_2$; and bacterial growth curves were calculated at 24, 48, 72, 96 and 120hrs after incubations. Results: MIC of Chungdae-tang aqueous extracts against Gardnerella vaginalis were detected as $3.906{\pm}2.344$(0.782~6.250) mg/$m\ell$, respectively. MIC of Clindamycin was detected as $0.010{\pm}0.006$(0.004~0.016) ${\mu}g/m\ell$ at same conditions. In addition, Clindamycin and Chungdae-tang aqueous extracts also showed marked dosage-dependent inhibition of bacterial growth, and more dramatical inhibitions were detected in Clindamycin+Chungdae-tang aqueous extracts MIC treatment as compared with each of single Clindamycin MIC and Chungdae-tang aqueous extracts MIC treatments, respectively. In addition, quite similar inhibitory effects on bacterial growth were detected in Clindamycin 1/4 MIC+Chungdae-tang aqueous extracts MIC treatment as compared with single Clindamycin MIC treatment in the present study. FIC index in combination of Chungdae-tang and Clindamycin were detected as $0.775{\pm}0.285$ (0.500~1.250) at Checkerboard microtiter assay. Conclusions: The results obtained in this study suggest that Chungdae-tang aqueous extracts showed antibacterial effects against Gardnerella vaginalis, and it also showed dosage-dependent inhibitory effects on the bacterial growth. In addition, combination treatment of Chungdae-tang aqueous extract with Clindamycin showed more potent inhibitory effects on the growth of Gardnerella vaginalis with FIC index $0.775{\pm}0.285$(0.500~1.250), respectively. It means, the combination of Chungdae-tang aqueous extract with Clindamycin is partially synergistic effects. It, therefore, is expected that effective dosages of Clindamycin will be reduced to 1/4 or over 1/4 levels as combination with Chungdae-tang extracts, respectively.

• Microbiology and Biotechnology Letters
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• v.26 no.5
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• pp.387-392
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• 1998

Brevibacterium lactofermentum, a gram-positive bacteria, has both the diaminopimelate (DAP) pathway and meso-DAP-dehydrogenase (DDH) pathway for L-lysine biosynthesis. To investigate importance of DDH pathway and the related ddh gene in lysine production, we introduced site-specific mutagenesis technique. A 300 bp DNA fragment central to the meso-DAP-dehydrogenase gene (ddh) of B. lactofermentum was used to inactive chromosomal ddh gene via homologous recombination. Southern hybridization analysis confirmed that the chromosomal ddh gene was disrupted by the vector sequence. The B. lactofementum ddh mutant obtained have an inactive DDH pathway. The results reveal that inactivation of the ddh gene in B. lactofermentum leads to dramatic reduction of lysine production as well as decrease of the growth rate, indicating that the DDH pathway is essential for high-level lysine production as well as biosynthesis of meso-DAP.