• Title/Summary/Keyword: acid-resistance

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Development of Streptococcus faecalis Strains Resistant to Rifampicin (리팜피신에 내성인 Streptococcus faecalis 균주의 개발)

  • 최응칠;김승호;권애란;이미정;오정자;김병각
    • YAKHAK HOEJI
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    • v.37 no.4
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    • pp.350-355
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    • 1993
  • The preparation of Streptococcus faecalis RSI is used as a medicinal preparation for human intestinal disorders. But the microbe in this preparation is very sensitive to rifampicin. If this preparation is taken with rifampicin, its therapeutic effect can not be expected. To develope rifampicin resistant mutants, the rifampicin sensitive strain S. faecalis RSI was treated with Nmethyl-N'-nitro-N-nitrosoguanidine(MNNG). Twelve strains of the MNNG-induced mutants showed distinct resistance to rifampicin and five mutants were selected for further studies. They also exhibited identical characteristics with the parent S. faecalis RSI when they were tested for lactic acid formation and growth inhibition of E. coli. From in vitro test, it was identified that rifampicin is not inactivated by certain factors of the rifampicin resistant mutants. Conclusively, the rifampicin resistant mutants are efficient strains that have insensitivity against rifampicin and original biochemical characteristics of the parent strain.

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Transdermal permeation-enhancing activity of N-adamantyl n-alkanamides for lbuprofen in the rabbit

  • Han, Suk-Kyu;Park, Yong-Hoon;Ko, Young-Ill;Kim, Young-Mi
    • Archives of Pharmacal Research
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    • v.19 no.2
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    • pp.95-99
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    • 1996
  • Four N-adamantyl n-alkanamides were prepared by amide condensation reaction between amantadine and n-alkanoic acid. Their enhancing activity on the penetration of ibuprofen through rabbit skin from petrolatum ointment was evaluated in in-vivo experiment. The experiments showed that the compounds have a strong transdermal penetration-enhancing activity, and their activities were comparable with that of Azone. The measurements of the fluorescence polarization of DP[-i-labelled DPPC liposomes showed that these compounds considerablly decreased the phase transition temperature of the liposomes. The mechanism of the transdermal penetration-enhancing activity of the compounds was ascribed to the reduction of the resistance to drug flux of the stratum corneum lipid layers due to the loose packing of the layers when the bulk head group of the enhancers inserts into the layers.

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Operational Study of the Phosphoric Acid Type Unit Fuel Cell (인산형 단위 연료전지의 조업 연구)

  • Lee, Kapsoo;Kim, Hwayong
    • Transactions of the Korean hydrogen and new energy society
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    • v.3 no.2
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    • pp.63-69
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    • 1992
  • Two unit cells were made and operated with oxygen and air as oxidants After 350 hours operation with oxygen, the open circuit voltage drop of unit cell was 30 mV and internal resistance increased. After 250 hours operation with air, the open circuit voltage drop was 130mV. And the open circuit voltage difference of two cases was 90mV. In order to improve the performance of the unit cell with air, the supplying method of the electrolyte and the mass transfer characteristics of the electrode should be studied.

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Synthesis and Antibacterial Activity of Chitosan-Phthalylsulfathiazole (Chitosan-phthalylsulfathiazole의 합성과 항균성)

  • 최봉종;이기창;황성규;오세영;김판기
    • Journal of Environmental Health Sciences
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    • v.23 no.4
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    • pp.50-56
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    • 1997
  • Applied for Drug Delivery System, polymer drug was prepared with chitosan and phthalylsulfathiazole. In spite of various application of chitin derivatives, commercial use of chitin has been limited due to highly resistance to chemicals and the absense of proper solvents. In this study, Chitosan were prepared from chitin which were deacetylated under various condition. The synthetic procedures of polymer drug were performed by acid chloride methods. The antibiotic activities of polymer drug exhibited growth-inhibitory activity against Staphylococcus aureus, Staphylococcus epidermidis, E. coli, Salmonella typhimurium, Klebsiella pneumoniae at the concentration of 471-514 $\mu$g/ml in general. Comparatively, Polymer drug exhibited broad antibacterial activity on MICs 897-1280 $\mu$g/ml against Gram-positive and Gram-negative bacteria including Staphylococcus aureus, Staphylococcus epidermidis and E. coli.

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A Study on the Micropores of BTCA Finished Cotton Fabrics (BTCA로 방추가공된 면직물의 미세기공구조 측정)

  • 최연주;유효선
    • Journal of the Korean Society of Clothing and Textiles
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    • v.26 no.7
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    • pp.1078-1084
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    • 2002
  • Cotton fabrics were treated with 1,2,3,4-butanetetracarboxylic acid(BTCA) to impart durable press performance, which is formaldehyde-free DP finishing reagent. The pore structures of BTCA treated cottons were compared using a reverse gel permeation chromatographic technique(reverse GPC). A series consisting 4 kinds of water soluble sugars was used to study the elution characteristics of columns prepared from cotton fibers. From these data, differences in pore size distribution in the control and BTCA treated cottons were distinguished. BTCA crosslinks cellulose molecules provided wrinkle resistance to the treated cotton fabrics through ester linkages. Although crosslinking of cotton with BTCA reduced accessible internal volume across the entire range of pore size, differences in line pores were larger than in small pores. BTCA treated cotton exhibited reductions over 40% in large pore sizes.

A Study on the Surface Properties of Wool Fabric Treated with Enzyme (효소가공 양모직물의 표면 성질에 관한 연구)

  • 박미라;김환철;박병기
    • Textile Coloration and Finishing
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    • v.13 no.4
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    • pp.227-233
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    • 2001
  • Wool fabrics were pre-treated with corona prior to treating with enzyme for shrinkage resistance. Commercial protease and cellulase were used for degradation of wool and the treatment conditions such as enzyme amount, treating time, and assistant chemicals. Friction coefficient and zeta-potential were measured to certificate an effect of treatment condition on the handle of wool fabric. Corona pretreatment make the wool fabric soft, which result in the decrease of friction coefficient and zeta-potential. Scale removal of wool surface was observed by scanning electron microscope. Amino acid analysis shows the effectiveness of enzyme, and corona pretreatment does not cause severe internal damage.

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The Effect of Complexing Agent on the Deposit Charateristics in the Electroless Nickel Plating Solution (무전해 니켈 도금액에서 착화제가 도금피막에 미치는 영향)

  • Jeon Jun-Mi;Koo Suck-Bon;Lee Hong-Kee;Park Hae-Duck;Shim Su-Sap
    • Journal of the Korean institute of surface engineering
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    • v.37 no.6
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    • pp.326-334
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    • 2004
  • Deposit charateristics of Electroless nickel(EN) were investigated with various complexing agents. As expected, the deposition rate of nickel is increased with pH and that of Phosphorous is decreased with pH. The result of SEM investigation shows that the rough surface crystallization is appeared with pH. It is show that the surface resistance of EN deposit is decreased with pH at 85$^{\circ}C$.

Molecular Cloning and Characterization of Soybean Cinnamoyl CoA Reductase Induced by Abiotic Stresses

  • So, Hyun-Ah;Chung, Eun-Sook;Cho, Chang-Woo;Kim, Kee-Young;Lee, Jai-Heon
    • The Plant Pathology Journal
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    • v.26 no.4
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    • pp.380-385
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    • 2010
  • Suppression subtractive hybridization was used to isolate wound-induced genes from soybean. One of the wound-induced genes, gmwi143 designated as GmCCR, showed high homology with genes encoding cinnamoyl-CoA reductase (CCR; EC 1.2.1.44). Deduced amino acid sequences encoded by GmCCR showed the highest identity (77%) with those of Acacia CCR. There are 2 CCR genes highly homologous to GmCCR in soybean genome based on Phytozome DB analysis. RNA expression of GmCCR was specifically induced by local and systemic wounding, drought, high salinity or by ultraviolet stress. Our study suggests that GmCCR may be involved in resistance mechanism during abiotic stresses in plants.

A Study of Mechanical Properties in Compression on High density Graphite Products with Expanded Graphite (고밀도 팽창흑연 성형품의 압축 특성에 관한 연구)

  • Shin, Y.W.
    • Journal of Power System Engineering
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    • v.10 no.1
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    • pp.52-59
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    • 2006
  • Graphite is well known as a material which has high-temperature thermostable property, chemical resistance against acid and alkaline state also is very easy to environment. Nowadays the need of graphite product is increasing rapidly because of its advantages. In this paper, the mechanical property of newly developed graphite products with high density is investigated with especially in compression test. I introduced the graphite specimens for this study by NGF method with two expandable graphite and compared to the specimens of commercial graphite sheet from expanded graphite which made by the rolling process. I investigated the characteristics of these materials by measuring specific weight, hardness, compressive strength and investigating structures by SEM, It is verified that the graphite products with NGF method has superior properties for using gasket materials than that of commercial graphite sheet.

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Characterization of a New Leuconostoc Species Isolated from Fresh Garlic

  • Lee, Se-Hi;Choi, Jong-Hoon;Kim, Youn-Soon;Kyung, Kyu-Hang
    • Food Science and Biotechnology
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    • v.14 no.3
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    • pp.416-419
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    • 2005
  • Unknown bacterium isolated from garlic was characterized using phenotypic methods, phylogenetic analysis, DNA-DNA hybridization, and cultural methods. The strain was identified as typical leuconostoc; Gram-positive, non-sporeforming, heterofermentative, catalase-negative and spherical. Although its 16S rRNA gene sequence showed high homology to Leuconostoc argentinum DSM $8581^T$(99.8%), DNA-DNA hybridization experiments indicated it represents novel genomic species in the genus Leuconostoc. The garlic-specific leuconostoc was more resistant to antimicrobial activity of garlic compared to other common laboratory lactic acid bacteria, and was even stimulated by low concentrations (1-2%) of garlic extract supplemented in trypticase soy broth. Growth stimulation was concentration-dependent when tested with residual aqueous layer after solvent extraction of fresh whole garlic extract.