• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2004년도 춘계 학술발표대회 개요집
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• pp.314-315
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• 2004

As environmental issue threatens to be aggravated, applications of bio-degradable plastic (Polybutylene Succinate:PBS) tend to be increased. However, improvement of mechanical characteristics of PBS is indispensable for further widespread actual applications. Therefore, in order to produce further functional P8S with improved mechanical characteristics, TiO$_2$ coatings on PBS substrate were prepared under various spraying conditions using plasma and HVOF spraying techniques. The effects of thermal spraying methods and spraying parameters on coating properties could be confirmed. Moreover, wear behavior for TiO$_2$ coatings on PBS substrate has been also reviewed and characterized.

• 한국세라믹학회지
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• 제25권3호
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• pp.300-306
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• 1988

The catalytic effect of salts on formation of ${\alpha}$-calcium sulfate hemihydrate under water vapor at atmospheric pressure was studied and the formation of q-calcium sulfate hemilydrate from by-product gypsum of phosphoric acid process was investigated. The order of catalytic effect of salts are as follow: Ammonium chloride>Sodium succinate>Calcium chloride>Sodium tartrate>Magnesium chloride The prismatic crystals was formed when ammonium chloride, calcium chloride and magnesium chloride was added, whereas the needle crystals was formed when sodium tartrate was added. Ammonium chlorideis most successful in catalytic effects in formation of ${\alpha}$-calcium sulfate hermihydrate for the by-product gypsum of phosphoric acid process.

• 한국수소및신에너지학회논문집
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• 제21권1호
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• pp.12-18
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• 2010

Photobiological hydrogen production using Rhodobacter sphaeroides KD131 was studied on the effect of light intensities and nitrogen sources. Media containing malate and glutamate were shown higher hydrogen production rate than that containing succinate and $(NH_4)_2SO_4$ at the $110\;W/m^2$ illumination by halogen lamp at $30^{\circ}C$. Media lacking glutamate as the nitrogen source exhibited higher hydrogen production than that containing glutamate. Initial cell concentration was optimized to 1.0 at the absorbance of 660 nm. Hydrogen production was increased by increasing the light intensity from 0 to $216\;W/m^2$ but the increasing rate declined over $108\;W/m^2$.

• Journal of Pharmaceutical Investigation
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• 제14권2호
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• pp.76-85
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• 1984

Antibiotic activity and antipyretic effect of three synthetic prodrugs, chloramphenicol acetylsalicylate (CAF-ASP), chloramphenicol naproxenate(CAF-NAX) and chloramphenicol acetaminophen succinate (CAF-SUC-ACET), were studied in vitro and in vivo. In the experimental results, the CAF-NAX showed the moat rapid absorption and the highest blood levels, and the CAF-SUC-ACET and CAF-ASP also were more rapid absorption and higher blood levels than controls, chloramphenicol and chloramphenicol palmitate. The synthetic prodrugs also showed the antipyretic effect by modified Roszkowski method using endotoxin.

• Biomolecules & Therapeutics
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• 제16권1호
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• pp.1-8
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• 2008

Mitochondria are important sensor of apoptosis. $H_2O_2-induced$ cell death rate was enhanced by serum deprivation. In this study, we investigated whether serum deprivation using 0.5 or 3 % FBS induces apoptotic cell death through mitochondrial enzyme activation as compared to 10 % FBS. Apoptotic cell death was observed by chromosome condensation and the increase of sub-G0/G1 population. Serum deprivation reduced cell growth rate, which was confirmed by the decrease of S-phase population in cell cycle. Serum deprivation significantly increased caspase-9 activity and cytochrome c release from mitochondria into cytosol. Serum deprivation-induced mitochondrial changes were also indicated by the increase of ROS production and the activation of mitochondrial enzyme, succinate dehydrogenase. Mitochondrial enzyme activity increased by serum deprivation was reduced by the treatment with rotenone, mitochondrial electron transport inhibitor. In conclusion, serum deprivation induced mitochondrial apoptotic cell death through the elevation of mitochondrial changes such as ROS production, cytochrome c release and caspase-9 activation. It suggests that drug sensitivity could be enhanced by the increase of mitochondrial enzyme activity in serum-deprived condition.

• 한국식물병리학회지
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• 제14권6호
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• pp.598-602
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• 1998

Twenty two rhizobacteria were isolated from the roots and rhizosphere of radish, carnation, potato and tomato. There isolates produced a fluorescent pigment in King's B medium and identified as Pseudomonas spp. These isolates colonized roots and rhizosphere of the host plants. In the study of cultural characteristics of the bacteria, the pH of the culture broth was changed from neutral (7.0) to alkali (8.8∼9.41) and the numbers of cells were increased from 106 to 108 after 40 hr of incubation in basal standard succinate medium. The salicylic acid production identified by pink color reaction were observed in 7 bacteria. Out of these 7 salicylic acid producing bacteria, only 2 strains of bacteria such as Pseudomonas fluorescens RS006, and Pseudomonas sp. EN401 were confirmed as salicylic acid producers by optical density measurement. Therefore, for screening of salicylic acid producing bacteria from the roots and rhizosphere, color reaction of the culture medium should be done in the first step, and then optical density measurement of culture extract should be made for the confirmation of salicylic acid production.

• Journal of Microbiology
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• 제39권4호
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• pp.334-337
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• 2001

The degradative pathway of homoprotocatechuate (HPC) is the bacterial routhe wherby 3,4-dihydrox-yphenylactic acid is catabolized to pyruvate and succinate by a series of sequential reactions . The HPC is catalzed by homoprotocatechuate 2, 3-dioxygenase(HPC-2,3O) to from 5-carboxymethy1-2-hydroxy-muco semialdehyde. In this study, the hha D gene encoding. HPC, 2, 3O was Cloned from the chromo-somal DNA of Pseudomonas sp. DJ-12 and its nucleotide sequence was analyzed. The open reding frame of hpaD gene was found to be composed of 864 nucleotide pairs and to encode a poypetide with 287 amino acide residues. The deduced amino acid sequence of the HPC-2,3O from Pseudomonas. sp. DJ-12 exhibited 60~64% homology with those of the corresponding enzymes from E. coli. Salmonella enterica, and Klebsiella pneumoniae.

• 공업화학
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• 제5권2호
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• pp.209-214
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• 1994

Mono alkyl glycerides have bean obtained in good yield by enzyme catalyst from soybean oil. The reaction was carried out in an oil rich microemulsion formula. Best results were obtained with sodium bis(2-ethyl hexyl) sulfo succinate(AOT), isooctane as hydrocarbon component and buffer of pH 7. The enzyme used was a 1,3-specific lipase which leaves the 2-position intact. However, the 2-monoglyceride formed slowly undergoes long chain acyl migration to 1-mono-glyceride. Optimal reaction time at $35^{\circ}C$ reaction temperature was found to be three hour.

• Journal of Microbiology and Biotechnology
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• 제15권2호
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• pp.281-286
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• 2005

We created a new graphite-Cu(II) electrode and found that the electrode could catalyze FADH$_2$ oxidation and FAD reduction coupled to electricity production and consumption, respectively. In a fuel cell with graphite-Cu(II) anode and graphite-Fe(III) cathode, the electricity was produced by coupling to the spontaneous oxidation of FADH$_2$ Fumarate and xylose were not produced from the enzymatic oxidation of succinate and xylitol without FAD, respectively, but produced with FAD. The production of fumarate and xylose in the reactor with FAD electrochemically regenerated was maximally 2- 5 times higher than that in the reactor with FAD. By using this new electrode with catalytic function, a bioelectrocatalysts can be engineered; namely, oxidoreductase (e.g., lactate dehydrogenase) and FAD can function for biotransformation without an electron mediator and second oxidoreductase for cofactors recycling.

• Journal of Ginseng Research
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• 제9권2호
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• pp.221-231
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• 1985

The effect of ginseng saponin on the activities of isocitrate lyase, palate synthase, succinate dehydrogenase, malate dehydrogenase and lipase have been investigated at the early phase of germinating soy-bean sprout and found that all the above enzymes were stimulated when the bean was rinsed for 24 hours with 10-4% saponin solution. The length of the saponin treated group was not longer than that of control group but the weight of the former was heavier (15%) than the latter. Total sugar content of test group was always much higher than that of control. From the above results, it was concluded that ginseng saponin might stimulate several enzymes of Soybean sprout during germination resulting in rapid growth of the Soybean sprout.