• Asian-Australasian Journal of Animal Sciences
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• v.5 no.3
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• pp.511-517
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• 1992

Ethanol was utilized by mixed rumen microbes, but addition of pentachlorophenol (25 mg/l), a methanogen inhibitor, suppressed the utilization of ethanol. Carbon monoxide (50% of the gas phase), a hydrogenase inhibitor, more strongly suppressed the utilization of ethanol, propanol, and butanol. These results suggest that the major ethanol utilizers are $H_2$ producers. Ethanol utilization was depressed at low pH (below 6.0). Since methanogens were shown to be relatively resistant to low pH, it appears that ethanol utilizers are particularly sensitive to low pH. Ruminococcus albus and R. flavefaciens in mono-culture produced ethanol from carbohydrate (glucose and cellobiose), even when a high level (170 mM) of ethanol was present. Ethanol was not utilized even in the absence of carbohydrate, but the co-culture of these bacteria with methanogens resulted in the utilization of ethanol, i.e., when $H_2$ was rapidly converted to $CH_4$, R. albus and R. flavefaciens utilized ethanol. These results suggest that ethanol is utilized when the electrons liberated by the oxidation of ethanol are rapidly removed, and ready electron disposal in ethanol-utilizing, $H_2$-producing bacteria is accomplished by the interspecies transfer of $H_2$.

• Journal of Food Hygiene and Safety
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• v.9 no.3
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• pp.141-149
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• 1994

To investigate the distribution of Vibrio parahaemopyticus in the southern 4 coastal areas, Vibrio parahaemolyticus was isolated from seawater, shellfish and sediment from May to October in 1991, and antimicrobial effect of grapefruit seed extract (GFSE) on the growth of isolated strains were examined. In the 120 sample from 4 coastal areas, 16 strains of Vibrio parahaemolyticus were isolated and identified. The distribution serotype of isolated strains was 10 types of monovalent k-antiserum. Especially k-5 and k-28 were highly distribyted with 3 and 4 strains. 31.3% of isolated strains showed positive on Kanagawa phenomenon test. All isolated Vibrio parahaemolyticus were sensitive to chloramphenicol and gentamycin, 5 and 6 strains were resistant to streptomycin and colistin, respectively. Isolated strains were compared with geographical, month and sample. The distribution of 16 isolated Vibrio parahamolyticus was high at Hadong with 50%(8 strains), on July with 43.8%(7 strains) and from seawater with 37.5%(6 strains) respectively. Minimal inhibitory level of GFSE to Vibrio parahaemolyticus was 50 ppm. With 100 ppm treatment of GFSE, the destroy of cell membrane function, outflow of cell ingredients and ghost morphology of cell were investigated.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.116.2-117
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• 2003

Late blight, caused by Phytophthora infestans, is one of the most destructive disease on potato and tomato cultivation. To analysis genetic diversity P. infeatans isolates were collected from potato and tomato fields in Korea. These pathogens contained both Al and A2 mating type with metalaxyl-resistant and sensitive isolates. Polymorphisms showed base on RAPD (Random Amplified Polymorphic DNA) in both potato and tomato isolates of P. infestans. Cluster analysis showed high level genetic variation in potato isolates of P. infestans than tomato isolates. P. infestans isolates were observed genetic diversity among them but not grouped among isolates related mating type and metalaxyl response. These results exhibited that P. infestans isolates showing genetic difference among them were distributed in Korea.

• Journal of Microbiology
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• v.42 no.1
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• pp.14-19
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• 2004

Salmonella enterica serovar Typhimurium DT104 (Salmonella Typhimurium DT104 or DT104) has been emerging as a common pathogen for human in Korea since 1997. In order to compare the genomic relationship and to search for the dominant strains in Korea, we conducted pulsed-field gel electrophoresis (PFGE) and IS200 fingerprinting of 25 epidemiological unrelated isolates from human and animals from Korea and cattle from America. Two Salmonella Typhimurium DT104 isolates from human in Korea and all 8 isolates from American cattle had indistinguishable patterns from the PFGE and IS200 fingerprinting but multidrug-resistant Salmonella Typhimurium isolates, including DT104, from Korean animals had diverse genetic patterns. The data suggest that a dominant DT104 strain might have circulated between Korean and American cattle and that it had a high level of clonality.

• Proceedings of the Microbiological Society of Korea Conference
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• 2005.05a
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• pp.143-147
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• 2005

The non-pathogenic, non-glycopeptide-producing actinomycete Streptomyces coelicolor carries a cluster of seven genes (vanSRJKHAX) that confers inducible, high-level resistance to vancomycin. The van genes are organised into four transcription units, vanRS, vanJ, vanK and vanHAX, and these transcripts are induced by vancomycin in a vanR-dependent manner. vanHAX are orthologuous to genes found in vancomycin resistant enterococci that encode enzymes predicted to reprogramme peptidoglycan biosynthesis such that cell wall precursors terminate in D-Ala-D-Lac, rather than D-Ala-D-Ala. vanR and vanS encode a two-component signal transduction system that mediates transcriptional induction of the seven van genes. vanJ and vanK are novel genes that have no counterpart in previously characterised vancomycin-resistance clusters from pathogens. VanK is essential for vancomycin resistance in S. coelicolor and it is required for adding Gly branch to stem peptides terminating D-Ala-D-Lac. Because VanK can recognise D-Lac-containing precursors but the constitutively expressed femX enzyme, encoded elsewhere on the chromosome, cannot recognize D-Lac-containing precursors as a substrate, vancomycin-induced expression of VanHAX in a vanK mutant is lethal. Further, femX null mutants are viable in the presence of glycopeptide antibiotics but die in their absence. Bioassay using vanJp-neo fusion reporter system also showed that all identified inducers for van genes expression were glycopeptide antibiotics, but teicoplanin, a membrane-anchored glycopeptide, failed to act as an inducer.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2004.10a
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• pp.48-52
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• 2004

We have found the role of rice mitogen-activated protein kinase kinase kinase (MAPKKK), OsEDR1, as controling hypersensitive response (HR) and increased disease resistance to rice blast fungus Magnaporthe grisea. Generation of transgenic rice plants through introduction of the over-expression construct of OsEDR1 using Agrobacterium-mediated transformation results in lesion mimic phenotype. Up-regulation of defense mechanism was detected through detection of increased transcription level of rice PBZ1 and PR1a. Inoculation of rice blast fungus on the lesion mimic transgenic lines displayed significantly increased resistance. The disease symptoms were arrested like HR responses which are commonly detected in the incompatible interactions. High accumulation of phenolic compounds around developing lesions was detected under UV light. There was variation among transgenic lines on the timing of lesion progression as well as the lesion numbers on the rice leaves. Transgenic lines with few lesions also show increased resistance as well as equal amount of grain yields compared to that of wild type rice cultivar Nipponbare. This is the first report of the MAPKKK as a positive regulator molecule on defense mechanism through inducing HR-like cell death lesion mimic phenotype. The application of OsEDR1 is highly expected for the development of resistant cultivars against rice pathogens.

• Tribology and Lubricants
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• v.32 no.1
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• pp.32-37
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• 2016

The wear characteristics of metal ball and seat in a metal-seated ball valve significantly affect the performances such as leakage and valve torque. In this work, the wear characteristics of metal ball and seat are experimentally investigated. A stainless steel ball and seat with a high corrosion-resistant coating are prepared and a component level test was performed. The hardness and surface roughness of specimens cut from the metal ball and seat are measured before and after the test using a micro-Vickers hardness tester and confocal microscopy, respectively. In order to assess the wear characteristics, the surfaces of the specimens are carefully examined after the test. The confocal microscope data show that the surface roughness values of both the ball and seat increase by a factor of 3-4, which may lead to an increase in valve torque. However, the wear of the seat is found to be more significant than that of the ball. In addition, a comparison of the surfaces of the ball and seat before and after testing revealed that adhesive and abrasive wear are the major wear mechanisms. The results of this study may aid in the design of metal-seated ball valves from the tribological point of view.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.4
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• pp.1639-1642
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• 2014

The multidrug resistance phenotype is one of the major problems in development of cancer cell resistance to chemotherapy. Some natural compounds from medicinal plants have demonstrated promising capacity in enhancing anticancer effects in drug resistant cancer cells. We aimed to investigate whether mangiferin might have an ability to re-sensitize MCF-7 breast cancer cells previously treated with short-term doxorubicin in vitro, through the modulation of efflux transporters, P-glycoprotein (P-gp), MRP1 and BCRP. We exposed MCF-7 breast cancer cells pretreated with doxorubicin for 10 days to mangiferin (10, 25 or 50 ${\mu}M$) for 96 hours. Afterwards, we evaluated influence on cell viability and level of mRNA expression of P-gp, MRP1 and BCRP. Doxorubicin given in combination with mangiferin at low concentrations (10 and 25 ${\mu}M$) failed to give significant reduction in cell viability, while at the highest concentrations, the combination significantly reduced cell viability. The mRNA expression analysis of P-gp, MRP1 and BCRP showed that mangiferin had inhibitory effects on P-gp but no effects on MRP1 and BCRP. In conclusion, we suggest that mangiferin at high concentrations can be used as chemosensitizer for doxorubicin therapy. This effect might be attributed by inhibitory effects of mangiferin on P-glycoprotein expression.

• JSTS:Journal of Semiconductor Technology and Science
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• v.13 no.6
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• pp.622-634
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• 2013

The circuit level implementation of nanoscale Insulated Shallow Extension Silicon On Nothing (ISE-SON) MOSFET has been investigated and compared with the other conventional devices i.e. Insulated Shallow Extension (ISE) and Silicon On Nothing (SON) using the ATLAS 3D device simulator. It can be observed that ISE-SON based inverter shows better performance in terms of Voltage Transfer Characteristics, noise margin, switching current, inverter gain and propagation delay. The reliability issues of the various devices in terms of supply voltage, temperature and channel length variation has also been studied in the present work. Logic circuits (such as NAND and NOR gate) and ring oscillator are also implemented using different architectures to illustrate the capabilities of ISE-SON architecture for high speed logic circuits as compared to other devices. Results also illustrates that ISE-SON is much more temperature resistant than SON and ISE MOSFET. Hence, ISE-SON enables more aggressive device scaling for low-voltage applications.

• Korean journal of applied entomology
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• v.29 no.3
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• pp.194-200
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• 1990

The diamondback moth (Plutella xylostella L.) was selected over 24 generations with fenvalerate. The resulting resistant strain was tested to study development of insecticide resistance and cross resistance to some insecticides in the laboratory. Insecticide resistance of diamondback moth at the 24th generation devleoped 66.2 fold compared to the parent strain for fenvalerate. The fenvalerate selected strain exhibited 145 fold, a high level of cross resistance to deltamethrin, and also showed 17.4-45.0 fold cross resistance to alphamethrin, cypermethrin, fenvalerate, permethrin, and tetramethrin in the pyrethroid insecticides. The fenvalerate selected strain showed 2.5-4.3 fold, low cross resistance to diazinon, dichlorvos, EPN, BPMC, cabaryl, and methomyl. However, it did not show cross resistance to acephate, fenitrothion, phenthoate, and carbofuran.