• Journal of Welding and Joining
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• v.18 no.6
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• pp.62-67
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• 2000

Metallurgical characteristics of bonded region and high temperature mechanical properties of heat resistant alloy, Fe-35Ni-26Cr during liquid phase diffusion bonding were investigated employing AM17 insert metal. The insert metal for bonding, AM17 was newly developed Ni-base metal using interpolation method. Bonding of specimens were carried out at 1,403~1,463K for 600s in vacuum. The microconstituents in the bonded interlayer disappeared in the bonding temperature over 1,423K. The microstructures, alloying elements and hardness distribution in the base metal. The tensile strength and elongation of the joints at elevated temperatures were the same level as one of the base metal in the bonding temperature over 1,423K. The creep rupture strength and rupture lives of joints were almost identical to those of base metal.

• Parasites, Hosts and Diseases
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• v.44 no.1 s.137
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• pp.43-48
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• 2006

Experimental murine models with high, intermediate and low levels of genetically based susceptibility to Leishmania major infection reproduce almost entire spectrum of clinical manifestations of the human disease. There are increasing non-comparative studies on immune responses against isolated antigens of L. major in different murine strains. The aim of the present study was to find out whether there is an antigen that can induce protective immune response in resistant and susceptible murine strains. To do that, crude antigenic extract of procyclic and metacyclic promastigotes of L. major was prepared and subjected to SDS-PAGE electrophoresis. Western-blotting was used to search for antigen(s) capable of raising high antibody level of IgG2a versus IgG1 in the sera of both infected resistant and susceptible strains. Two novel antigens from metacyclic promastigotes of L. major (140 and 152 kDa) were potentially able to induce specific dominant IgG2a responses in BALB/c and C57BU6 mice. The 2 antigens also reacted with IgG antibody of cutaneous leishmaniasis patients. We confirm that 140 and 152 kDa proteins of L. major promastigotes are inducing IgG production in mice and humans.

• Journal of Welding and Joining
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• v.18 no.4
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• pp.96-103
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• 2000

This study investigated the effects of bonding temperature and bonding atmosphere on high temperature mechanical properties of transient liquid phase(TLP) bonded joints of heat resistant alloy using MBF-50 insert metal. Specimens were bonded at 1,423~1,468K for 600s. Microconstituents of {TEX}$Cr_{7}(C,B)_{3}${/TEX}were formed in the bonded region when the bonding temperature was low. The amount of microcostituents in the bonded layer decreased with increasing the bonding temperature, and the microconstituents in the bonded layer disappeared at the bonding temperature above 1,468K. The tensile strength of the joints at elevated temperatures increased with the increase the bonding temperature and was the same level as one of the base metal in the bonding temperature over 1,453K. Microstructure and alloying element distributions of the bonded region bonded in Ar and $N_2$atmosphere were similar to those of the bonded in vacuum. The creep rupture strength and rupture lives of joints were almost identical to those of base metal.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.27 no.4
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• pp.439-451
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• 1982

In fact, rice cultivation technique from 1962 to 1970 was very slight, but this technique from 1970 to now was remarkably developed in Korea, it was due to development of high fretilizer responsive and lodging resistant variety, Tongil; ie. Ind. ${\times}$ Japonica remote-cross rice variety. The main factors of this development is as follow: Firstly the most farmer (more than 90%) used newly developed seedling growth method; polyethylene film covered protected nursery bed. Secondly date of transplanting (middle or late part. of May) was earlier 10-15days than before 1970. Thirdly new varieties were highly lodging resistant at high fertilizer level $(N-P_2O_5-K_2O:15-9-11 kg/l0a)$. However, this level is 50% increased one than it for Japonica varieties. At forth planting density increased up to 75-80 hills per $3.3m^2$. Added to these factors, farm labor shortage and wage increase due to economic development gave a chance for introduction of transplanting machine to farmer in 1977. It's use increased for 100, 800 ha in 1981. The most of farmers are using herbicides and weed control system dependoing on wood composition has been established and disseminated to farmer.

• Journal of Korean Society of Forest Science
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• v.85 no.3
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• pp.372-380
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• 1996

This study was carried out to study the resistant substances to pine needle gall midge and seasonal variation of phenolic compounds in pine needles among susceptible and resistant species to pine needle gall midge. Free and water soluble phenolic compounds contained in pine needles showed seasonal variations among pine species. But, catechol, vanillic acid and syringic acid including phenolic compounds showed no variation between pine species, even the amount of those component varied by the seasons. Salicylic acid in pine needles showed 140ppm in Pinus virginiana, 35ppm in Pinus thunbergii and 72ppm in hybrid pine, Pinus thunbergii${\times}$P. virginiana, but traces in Pinus densiflora on May and June, hatching season in larvae of pine needle gall midge. There was high level of salicylic acid in resistant species to pine needle gall midge but traces in susceptible species. As our previous researches, the necrosis rate of larvae of pine needle gall midge showed high level on the solution of phenolic compounds extracted from needles of P. virginiana and salicylic acid, and there was no gall formation in P. virginiana, so that salicylic acid in pine needles seems to have relation with those results. Therefore, it is estimated that salicylic acid is resistant substance to pine needle gall midge.

• Korean journal of applied entomology
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• v.23 no.2 s.59
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• pp.89-95
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• 1984

Sixty isolates of Dendrophoma obscurans isolated from 19 important strawberry growing areas of Korea were tested in vitro for resistance to thiophanate-methyl and iprodione. Naturally-occurring thiophanate-methyl-resistant isolates were about 43 percents of isolates tested, whereas iprodione-resistant isolates were 10 percents. All these resistant isolates except SU 1 and SU 2, which were highly resistant to thiophanate-methyl, showed a week level of resistance. Iprodione-resistant isolates were readily obtained in vitro, when mycelial disk of the fungus was incubated on PDA media containing iprodione at the concentrations of $1{\mu}g/ml\;and\;10{\mu}g/ml$, but no thiophanate-methyl-resistant isolate from the mycelia with or without UV irradiation. All these artificially-obtained iprodione-resistant isolates were showed a high degree of resistance. On the strawberry leaves, thiophanate-methyl and iprodione were no longer effective to all resistant isolates at the recommended concentration, and the protective value to highly resistant isolates was much less than that of weakly resistant isolates. Isolates resistant to thiophanate-methyl were also resistant to benomyl but iprodione-resistant isolates did not show cross-resistance to thiophanate-methyl, benomyl, captan and zineb. Captan controlled both thiophanate methyl-resistant and iprodione-resistant isolates as effectively as sensitive isolates.

• Nutrition Research and Practice
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• v.3 no.2
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• pp.149-155
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• 2009

In this study, we investigated the heat effect of digestion-resistant fraction (RF) from soybean on retarding bile acid transport in vitro. The RFs from soybean retarded bile acid transport. A raw, unheated RF of soybean (RRF-SOY) was significantly more effective than the heated RF of soybean (HRF-SOY). The RS1 which physically trapped in milled grains and inaccessible to digestive enzyme after 18 hrs incubation level of content in RRF-SOY was found to be as high as 24.1% and after heating the RS1 of HRF-SOY was significantly reduced to 16.8%. The X-ray diffraction pattern of RF from soybean was altered after heat treatment. The RFs from soybean were characterized by peak at diffraction angles of $12.0^{\circ}$ and $20.0^{\circ}$ corresponding to RS content. Cellulose contents of RRF-SOY was 5% higher than that of HRF-SOY and pentosan contents of RRF-SOY was 5% higher than that of HRF-SOY, too. Whereas the hemicellulose content of RRF-SOY was 13% lower than HRF-SOY.

• Biomedical Science Letters
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• v.5 no.1
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• pp.95-100
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• 1999

It is generally difficult, time-consuming, and expensive for the clinical laboratory to detect vancomycin resistant enterococci (VRE). The aim of this study was to develop and evaluate the multiplex polymerase chain reaction (PCR) assay system as a diagnostic tool for the rapid detection of VRE from clinical samples and/or for the identification of VRE from the bacterial strains isolated from clinical specimens. Specific primers, designed from the nucleotide sequences respectively encoding the vanA, vanB, vanC-1, vanC-2/3 genes in enterococci, were coupled in a multiplex PCR assay system. With this multiplex PCR assay system, we investigated the incidence rates and types of VRE isolated from clinical samples. A total of 75 strains of enterococci were isolated in 3 general hospitals in Korea. Of these isolates, 36 strains showed a pattern of high-level vancomycin resistance which associated with vanA gene, whereas 18 strains showed low-level vancomycin resistance associated with vanC-1 or vanC-2/3 gene. Thus, multiplex PCR assay method established in this study could be applied for the rapid detection of VRE.

• Korean Journal of Breeding Science
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• v.42 no.3
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• pp.207-211
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• 2010

'Taedong Valley' is a high yielding and processing potato cultivar, which is a clonal selection resulting from a cross between 'W870' and 'A88431-1'. It is a medium maturating cultivar with medium plant height and light green foliage. 'Taedong Valley' has profuse flowering habit and light purple flowers. Tubers are smooth, round, and with yellow skin, light yellow flesh, medium eye depth. Tubers have medium dormancy and good keeping quality. 'Taedong Valley' has stable yield under wide range of climatic conditions. It is resistant to common scab and potato virus Y, but moderately susceptible to late blight. It is also resistant to most of the disorders, particularly dehiscence, hollow heart and internal brown spots. This cultivar has high level of tuber uniformity and capable of yielding 43.6 t/ha which is about 9.0% higher than the control potato cultivar 'Atlantic' under optimum agronomical practices.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.1
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• pp.52-58
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• 1995

5-methyltryptophan（5MT） resistant mutant plants （MRl） were analyzed for characterization of anthranilate synthetase （AS） and tryptophan synthetase （TS） enzymes. The enzyme was measured in crude extracts from MR1 and control seedlings of Danggin inbred line. There was no significant difference in the level of AS between MR1 and control seedlings when grown on MS medium without 5MT. However, MR1 seedlings grown on MS medium with 25mg/L 5MT showed the level of AS twice higher than that of control seedlings. The activity of AS was inhibited to 50％ in untreated plants when 4mg /L L-tryptophan was added to their extracts. Extracts from MR1 plants required about four times higher concentration of amino acid to cause equal inhibition. In the TS assay, the activity observed in MR1 seedlings was four times higher than that of control seedlings. We have also isolated and sequenced the gene which encoding the tryptophan synthetase B subunit （TSB） from maize. The gene encodes polypeptides with high homology to TSB isolated from other plants, and is expressed in all the developmental stages examined. Northern hybridization analysis indicated that the gene expression in MR1 seedlings grown on MS medium showed a higher level than in control seedlings.