• The Korean Journal of Mycology
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• v.37 no.1
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• pp.65-72
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• 2009

For the breeding purpose, in this study we attempted to select a new Lentinula edodes strain by comparing mycelial growth rate, fruit-body quality and mushroom productivity per substrate weight of hybrid strains with parent strains. Nineteen hybrid strains were made by cross of di-karyotic and mono-karyotic to develop strains suitable for sawdust cultivation of L. edodes. Among the nineteen strains, ten were selected by comparing mycelial growth rate on PDA media and wood rot on sawdust-based substrates. The most mushroom harvesting was achieved by 100 days incubation from KFRI 960, KFRI 961, KFRI 962, KFRI 963, KFRI 964, KFRI 971, KFRI 973 and 125 days from KFRI 968, 970. Experiment of incubation periods with the ten strains showed that there were productivity differences between 100 and 150 days incubations. Through comparison of hybrid strains' mushroom productivity it was found that there was no difference in mushroom productivity through crossing high temperature types with high temperature types, crossing low temperature types with high temperature types and crossing unknown temperature types with high temperature types, but there was difference through crossing middle temperature types with high temperature types. Hybrid strains showed better productivity compared with parent strains. Fruiting temperature type analysis of hybrid strains confirmed that strains of high temperature types have a dominant character.

• Journal of Mushroom
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• v.13 no.1
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• pp.41-49
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• 2015

In order to breed new strains of oak mushroom, Lentinula edodes, on the sawdust cultivation, we collected 10 from Korea, Taiwan and China respectively and examined somatic incompatibility, morphological features of fruiting body and productivity. Four strains(SANJO701HO, FMRI2534, FMRI2337 and FMRI2613) shown remarkable results, were confirmed with parental strains. 80 monokaryotic strains derived from the selected 4 parental strains, were selected and 117 hybrid strains were made by mono-mono mating. Aslo, Physiological characteristics were investigated. Average of the mycelial growth of hybrid strains of mating combination SANJO701HO-FMRI2337 was approximately 10% lower than other mating combinations. Overall, This study was founded to develop new varieties of L. edodes. The productivity of new 117 strains on sawdust cultivation needs continued research.

• Journal of Mushroom
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• v.13 no.4
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• pp.294-300
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• 2015

We cultivated 117 hybrid strains of Lentinula edodes in greenhouse. 5 hybrid strains(07-55, 07-66, 07-84, 07-93 and 07-117) were selected from comparison of their characteristics of fruiting body and productivity. Biological efficiency of 5 hybrid strains was investigated 36.1(07-66), 35.6(07-117), 27.1(07-93), 25.7(07-84) and 6.5%(07-55), respectively. Selected strains 07-66, 07-117 and 07-93 showed high biological efficiency but observed commercially low quality fruiting body. Temperature type of fruiting body of 5 hybrid strains observed as follows high temperature type(07-117), mid temperature type(07-66 and 07-84) and low temperature type(07-55 and 07-93). Temperature type of fruiting body of 07-93 strain has wide range relatively. In the results, 07-84 strain was selected finally with consideration for quality of fruiting body, productivity and temperature type($8-21^{\circ}C$) in farm test.

• The Korean Journal of Mycology
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• v.39 no.2
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• pp.99-104
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• 2011

Shiitake breeding requires the procedures of mating of two different parental strains and selection of hybrid strains that have good traits for the mushroom production. In this study, we tested the possibility of the use of chromogenic plate-based assay for extracellular enzyme production in order to assess and find good biochemical properties-possessed hybrid strains that were generated from genetic cross of the monokaryotic strains derived from two different parental strains of Lentinula edodes Sanjo-101ho and Sanjo-108ho. We observed that there was difference in the ability of producing ${\beta}$-glucosidase, avicelase, CM-cellulase, amylase, pectinase, xylanase, and protease among the monokaryotic strains. We could also comparatively assess that the ability of the seven extracellular enzymes production in the hybrid strains depended on the mating combination of the monokaryotic strains. Our results demonstrate that the assessment method for extracellular enzyme production using chromogenic plate assay could be usefully applied to the assessment of the hybrid strains derived from the breeding procedure of L. edodes.

• Transactions of Materials Processing
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• v.12 no.1
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• pp.49-59
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• 2003

To reduce the cost of finite element analyses for sheet forming, a 3D hybrid membrane/shell method has been developed to study the springback of anisotropic sheet metals. In the hybrid method, the bending strains and stresses were analytically calculated as post-processing, using incremental shapes of the sheet obtained previously from the membrane finite element analysis. To calculate springback, a shell finite element model was used to unload the final shape of the sheet obtained from the membrane code and the stresses and strains that were calculated analytically. For verification, the hybrid method was applied to predict the springback of a 2036-T4 aluminum square blank formed into a cylindrical cup. The springback predictions obtained with the hybrid method was in good agreement with results obtained using a full shell model to simulate both loading and unloading and the experimentally measured data. The CPU time saving with the hybrid method, over the full shell model, was 75% for the punch stretching problem.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.03b
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• pp.62-65
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• 1999

To reduce the cost of finite element analyses for sheet forming a 3D hybrid membrance/sheel method has been developed to study the springback of anisotropic sheet metals. in the hybrid method the bending strains and stresses were analytically calculated as post-processing using incremental shapes of the sheet obtained previously from the membrane finite element analysis. To calculate springback a shell finite element model was used to unload the final shape of the sheet obtained from the membran code and the stresses and strains that were calculated analytically. For verification the hybrid method was applied to predict the springback of a 2036-T4 aluminum square blank formed into a cylindrical cup. the springback predictions obtained with the hybrid method was in good agreement with results obtained using a full shell model to simulateboth loading an unloading and the experimentally measured data. The CPU time saving with the hybrid method over the full shell model was 75% for the punch stretching problem.

• Korean Journal of Microbiology
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• v.24 no.3
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• pp.211-220
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• 1986

Nitrogen fixation (nif) genes of Rhizobium leguminosarum were transferred to nif Klebsiella pneumoniae and E. coli by conjugation after partial heat induction of $RP_4$ :: Mu cts in Rhizobium $R^+$ transconjugant, and the hybrid plasmids in the transconjugant strains were isolated and characterized. In order to transfer the nif genes from Rhizobium, the hybrid plasmid $RP_4$ :: Mu cts was transferred by conjugation from E. coil to the symbiotic nitrogen fixer, R. leguminosarum. After stabillity test, the $RP_4$ :: Mu cts in Rhixobium $R^+$ transconjugant was subjected to partial heat induction by culturing it statically at $38^{\circ}C$ for 16 hours, and then conjugated with the nif defective mutant strains of K. pneumoniae or nif mutant strains of E. coli having whole nif gene plasmid. Recombinant strains of K. pneumoniae, which could grow in a N-free medium and exhibit the nitrogenase activity were selected. However, in the case of E. coli, they could grow well in a NA medium containing antibiotices, but hardly frow in a N-free medium. The hybrid plasmids in these transconjugal strains were isolated by gel electrophoresis and compared their molecular sizes.

• Composites Research
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• v.13 no.3
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• pp.21-29
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• 2000

The optimum design of hybrid laminated composites for iso-strain structure has been studied by controling fiber orientations and thicknesses of each layer. Fiber orientations and thicknesses of each layer for iso-strain structure were designed. Combining the laminates of each layer of different reinforcing material, the constitutions of hybrid laminated composite for iso-strain structure were obtained. All these calculations were formed on computer systems, automatically for the hybridization. Using the data of some specific laminated composite such as glass and aramid reinforced composites, the constitutions of hybrid laminated composites for iso-strains structure were designed and verified by lamination theory. The strains of each layer of hybrid laminated composites are calculated and they turned out to be good agreements with the results obtained lamination theory.

• Journal of Environmental Health Sciences
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• v.50 no.4
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• pp.274-281
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• 2024

Background: One of the major causes of pathogenic E. coli is the feces of infected livestock, and the management of the livestock environment is necessary to prevent pathogenic E. coli. Objectives: The prevalence of pathogenic E. coli was identified from livestock environments, and the molecular characteristics and antibiotic resistance profiles of the isolated pathogenic E. coli strains were analyzed. Methods: In 2022 and 2023, nine points of livestock houses at sites in Chungcheongnam-do Province were selected, and 100 cow feces or soil samples around the livestock houses were collected once per month. Pathogenic E. coli was isolated by selective culture and identified using multiplex PCR. Antibiotic resistance was tested on the isolated strains by using VITEK-2, and candidate strains were selected to perform 16s rRNA sequencing and phylogenetic analysis. Results: A total of 100 samples were tested, and 60 pathogenic E. coli strains were isolated. Of these, 45 and 15 isolates were determined to be single and hybrid pathogenic E. coli , respectively. Among the 15 hybrid pathogenic E. coli strains, eight, five, and two strains were respectively identified as EHEC/ETEC, EHEC/EPEC, and EHEC/ETEC/EPEC hybrids. All 45 isolates showed resistance to at least one antibiotic, and they were susceptible to cefotaxime, amikacin, nalidixic acid, and ciprofloxacin. The highest resistance was against cefalotin, tetracyclin, and ampicillin (20.0%~58.3%). The 16s rRNA sequences of candidate isolates revealed nucleotide sequence identities of 99.1% to 100%. Conclusions: In order to manage pathogenic E. coli from the One Health animal environment perspective, the characteristics of the occurrence of pathogenic E. coli from the livestock environment and molecular biology and antibiotic resistance to isolated strains were analyzed. In order to prevent and manage the occurrence of pathogenic E. coli, these monitoring studies must be continuously conducted.

• Journal of Sericultural and Entomological Science
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• v.40 no.1
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• pp.27-32
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• 1998

One indigenous polyvoltine strain (Nistari) and two bivoltine strains viz. P5 and NB18 along with one bivoltine hybrid (P5$\times$NB18) were subjected for studies on the differences on some physiologically important biomolecules like protein, nucleic acids and cholesterol. Ovarian protein and RNA content remained significantly high in the bivoltine races and their hybrid over multivoltine breed, while, DNA and cholesterol content remained significantly low in all the breeds and the hybrid as compared to Nistari strain. However, the ovarian weight was higher in both the bivoltine breeds and their hybrid than that of Nistari. Higher ovarian weight together with more protein and RNA concentrations reflect the preparatory phase for production of diapausing eggs by the bivoltine silknoths and their hybrid. The variations in biochemical parameters studied herein, thus establish a distinct difference in the overt reproductive physioiogy between multivoltine and bivoltine silkworms.