• Smart Structures and Systems
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• v.5 no.1
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• pp.43-54
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• 2009

This study introduces a novel approach for locating damage in a structure using wireless sensor system with local level computational capability to alleviate data traffic load on the centralized computation. Smart wireless sensor systems, capable of iterative damage-searching, mimic an optimization process in a decentralized way. The proposed algorithm tries to detect damage in a structure by monitoring abnormal increases in strain measurements from a group of wireless sensors. Initially, this clustering technique provides a reasonably effective sensor placement within a structure. Sensor clustering also assigns a certain number of master sensors in each cluster so that they can constantly monitor the structural health of a structure. By adopting a voting system, a group of wireless sensors iteratively forages for a damage location as they can be activated as needed. Since all of the damage searching process occurs within a small group of wireless sensors, no global control or data traffic to a central system is required. Numerical simulation demonstrates that the newly developed searching algorithm implemented on wireless sensors successfully localizes stiffness damage in a plate through the local level reconfigurable function of smart sensors.

• Korean Journal of Metals and Materials
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• v.46 no.3
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• pp.144-149
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• 2008

Equal channel angular pressing (ECAP) has been studied intensively over the decade as a typical top-down process to produce ultrafine/nano structured materials. ECAP has successfully been applied for a processing method of severe plastic deformation to achieve grain refinement of magnesium and to enhance its low ductility. However, difficult-to-work materials such as magnesium and titanium alloys were susceptible to shear localization during ECAP, leading to surface cracking. The front pressure, developed by Australian researchers, can impose hydrostatic pressure and increase the strain level in the material, preventing the surface defect on workpiece. In the present study, we investigated the deformation and fracture behavior of pure magnesium using experimental and numerical methods. The finite element method with different ductile fracture models was employed to simulate plastic deformation and fracture behavior of the workpiece.

• Mycobiology
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• v.50 no.1
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• pp.79-85
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• 2022

Strawberries are a popular economic crop, and one of the major plantations and exporting countries is Korea in the world. The Fusarium oxysporum species complex (FOSC) is a soil-borne pathogen with genetic diversity, resulting in wilt disease in various crops. In Korea, strawberries wilt disease was first reported in the 1980s due to the infection of FOSC, causing significant economic damage every year. The causal agent, F. oxysporum f. sp. fragariae, is a soil-borne pathogen with a characteristic of FOSC that is difficult to control chemically and mutates easily. This study obtained genetic polymorphism information that was based on AFLP, of F. oxysporum f. sp. fragariae 91 strains, which were isolated from strawberry cultivation sites in Gyeongsangnam-do and Chungcheongnam-do, and compared strains information, which was the isolated location, host variety, response to chemical fungicide, and antagonistic bacteria, and mycelium phenotype. As a result, AFLP phylogeny found that two groups were mainly present, and group B was present at a high frequency in Gyeongsangnam-do. Group B proved less sensitive to tebuconazole than group A through Student's t-test. In addition, the fractions pattern of AFLP was calculated by comparing the strain information using PCA and PERMANOVA, and the main criteria were separated localization and strawberry varieties (PERMANOVA; p< 0.05). And tebuconazole was different with weak confidence (PERMANOVA; p< 0.10). This study suggests that the F. oxysporum f. sp. fragariae should be continuously monitored and managed, including group B, which is less chemically effective.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.4
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• pp.805-817
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• 2009

This study was to investigate central localization of neurons projecting to the urinary bladder and urinary bladder-related acupoints(Wijung, $BL_{40}$) and neurons of immunoreactive to hormones and hormone receptors regulating urinary bladder function by using peudorabies virus(PRV). In this experiment, Bartha's strain of pseudorabies virus was used in rats to trace central localization of urinary bladder-related neurons and urinary bladder-related acupoints($BL_{40}$) which can regulate urinary system. PRV was injected into the urinary bladder and acupoints($BL_{40}$) related urinary system. After six days survival of rats, mainly common labeled neurons projecting to the urinary bladder and urinary bladder-related acupoints were identified in spinal cord, medulla, pons and diencephalon by PRV immunohistochemical staining method. First-order PRV labeled neurons projecting to urinary bladder and urinary bladder-related acupoints were found in the cervical, thoracic, lumbar and sacral spinal cord. Commonly labeled preganglionic neurons were labeled in the lumbosacral spinal cord and thoracic spinal cord. They were found in the lateral horn area(sacral parasympathetic nucleus and intermediolateral nucleus), lamina V-X, intermediomedial nucleus and dorsal column area. The area of sensory neurons projecting to urinary bladder and Wijung($BL_{40}$) was L5-S2 spinal ganglia and T12-L1 spinal ganglia, respectively. In the brainstem, the neurons were labeled most evidently and consistently in the nucleus of tractus solitarius, area postrema, dorsal motor nucleus of vagus nerve, reticular nucleus, raphe nuclei(obscurus, magnus and pallidus), C3 adrenalin cells, parapyramidal area(lateral paragigantocellular nucleus), locus coeruleus, subcoeruleus nucleus, A5 cell group, Barrington's nucleus and periaqueductal gray matter. In the diencephalon, PRV labeled neurons were marked mostly in the paraventricular nucleus and a few ones were in the lateral hypothalamic nucleus, posterior hypothalamic nucleus, ventromedial hypothalamic nucleus, arcuate nucleus, median eminence, perifornical nucleus, periventricular nucleus and suprachiasmatic nucleus. In cerebral cortex, PRV labeled neurons were marked mostly in the frontal cortex, 1,2 area, hind limb area, agranular insular cortex. Immunoreactive neurons to Corticotropin releasiing factor(CRF), Corticotropin releasiing factor-receptor(CRF-R), c-fos and serotonin were a part of labeled areas among the virus-labeled neurons of urinary bladder and Wijung($BL_{40}$). The commonly labeled areas were nucleus tractus solitarius, area postrema, reticular nucleus, raphe nuclei(obscurus, magnus and pallidus), locus coeruleus, A5 cell group, Barrington,s nucleus, arcuate nucleus, paraventricular nucleus, frontal cortex 1, 2 area, hind limb, and perirhinal(agranular insular) cortex. These results suggest that overlapped CNS locations are related with autonomic nuclei which regulate the functions of urinary bladder-relate organs and it was revealed by tracing PRV labeled neurons projecting urinary bladder and urinary bladder-related acupoints. These commonly labeled areas often overlap with the neurons connected with hormones and hormone receptors related to urination.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.78.2-79
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• 2003

Pepper defensin ( CADEFl) clone was isolated from cDNA library constructed from pepper leaves infected with avirulent strain Bv5-4a of Xanthomonu campestris pv. vesicatoria. The deduced amino acid sequence of CADEFl is 82-64％ identical to that of other plant defensins. Putative protein encoded by CADEFl gene consists of 78 amino acids and 8 conserved cysteine residues to form four structure-stabilizing disulfide bridges. Transcription of the CADEF1 gene was earlier and stronger induced by X campestris pv. vesicatoria infection in the incompatible than in the compatible interaction. CADEF1 mRNA was constitutively expressed in stem, root and green fruit of pepper. Transcripts of CADEFl gene drastically accumulated in pepper leaf tissues treated With Salicylic acid (SA), methyl jasmonate (MeJA), abscisic acid (ABA), hydrogen Peroxide (H$_2$O$_2$), benzothiadiazole (BTH) and DL-${\beta}$-amino-n-butyric acid (BABA). In situ hybridization results revealed that CADEF1 mRNA was localized in the phloem areas of vascular bundles in leaf tissues treated with exogenous SA, MeJA and ABA. Strong accumulation of CADEF1 mRNA occurred in pepper leaves in response to wounding, high salinity and drought stress. These results suggest that bacterial pathogen infection, abiotic elicitors and some environmental stresses may play a significant role in signal transduction pathway for CADEF1 gene expression.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.78.1-78
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• 2003

An osmotin-like protein (CAOSMl) gene was isolated from pepper leaves infected with the avirulent strain Bv5-4a of Xmthomonas campestris pv. vesicatoria. The cDNA encodes a polypeptide of 250 amino acids with a molecular mass of 27, 361 Da. Its amino acid sequence is highly homologous to various osmotin-like proteins from other plant species. The CAOSMl gene expression was organ- and tissue-specifically regulated In pepper plants. The CAOSMl mRNA was intensely localized in the endodermis area of root tissue and in the phloem cells of vascular bundles of red fruit tissue, but not in leaf, stem, and green fruit tissues of healthy pepper plants. Infection by X. c. pv vesintoria, Colletotrichum coccodes, or Phytopkhora capsici iinduced CAOSMl transcription in the leaf or stem tissues. Expression of the CAOSMl gene was somewhat higher in the incompatible than the compatible interactions of pathogens with pepper. The CAOSMl mRNA was prevalently localized in the phloem cells of the vascular bundle of leaf tissues infected by C. coccodes. The CAOSMl gene was activated in leaf tissues by treatment with ethylene, methyl jasmonate, high salinity, cold acclimation and mechanical wounding, but not by abscisic acid (ABA) and drought. These results indicate that the pepper CAOSMl protein functions in response to Pathogens and some abiotic stresses in pepper plants

• Maxillofacial Plastic and Reconstructive Surgery
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• v.20 no.2
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• pp.173-183
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• 1998

$TGF-{\beta}$ is one of growth factors that may be involved in the formation of bone and cartilage. Multiple studies demonstrate that $TGF-{\beta}$ is involved in regulating cell proliferation, differentiation and matrix synthesis, events observed in frature healing. The apperance of $TGF-{\beta}$ in the fracture during healing was evaluated by immunohistologic localization of $TGF-{\beta}$ using antibody. Twenty Sprauge-Dawley strain white male rats, each weiging about 150grams were used and divided two groups. The one group, the $2{\times}2mm$ bony defect was formed in the right femur. The other group, $4{\times}2mm$ bony defect was formed in right femur. Both group were sacrificed at 3day, 1, 2, 3, 4 week and femur were harvested, paraffin sections were stained with H & E, MT stain, immunihistochemical staining with $TGF-{\beta}$ antibody and observed under light microscope. The result were as follows: 1. New bone formation and cartilagenous tissue was seen at 3day. And in the $2{\times}2mm$ bony defect group, $TGF-{\beta}$ stained the cell surounding new bone. 2. The osteoclast and trabecular was seen at 1week. $TGF-{\beta}$ stained the osteoblast and in the $2{\times}2mm$ bony defect group was stained more than $4{\times}2mm$ bony defect group. 3. The lamella bone and trabecule was seen from 3, 4week, and $TGF-{\beta}$ stained almost negative. From the above finding, we could concluded that $TGF-{\beta}$ stained the osteoblast at early stage and 1week, the peak stain was seen from 1week, and then decreased, almost negative stain was seen at 3, 4week.

• KSBB Journal
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• v.11 no.3
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• pp.270-275
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• 1996

Heterologous expression of glucose oxidase gene using recombinant yeast has been carried out. Polymerase chain reaction was conducted to obtain the gene encoding glucose oxidase from Aspergillus niger and sequence comparison indicated the cloned 1.9kb DNA fragment appeared to be the glucose oxidise structural gene containing a signal sequence for extracellular location. Transforming shuttle vector was constructed with YEp352 to express the cloned glucose oxidase gene under the control of either GAL1 or GAL10 promoter. Plate assay of recombinant yeasts has shown that GAL1 promoter was more effective in yielding glucose oxidise than GAL10 promoter. Among the five different concentrations of galactose tried, 1% galactose showed the highest induction of glucose oxidase. Cellular localization experiment of recombinant enzyme using spheroplast revealed that most of enzymes (80%) were secreted into culture media in contrast to A. niger. There is no difference in heat-stability of recombinant enzyme up to $50^{\circ}C$ compared to the glucose oxidase from A. niger However, a dramatic reduction of enzyme activity was observed in both enzymes at $60^{\circ}C$.

• Journal of Microbiology and Biotechnology
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• v.30 no.8
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• pp.1142-1148
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• 2020

Mitochondria play a vital role in iron uptake and metabolism in pathogenic fungi, and also influence virulence and drug tolerance. However, the regulation of iron transport within the mitochondria of Cryptococcus neoformans, a causative agent of fungal meningoencephalitis in immunocompromised individuals, remains largely uncharacterized. In this study, we identified and functionally characterized Mrs3/4, a homolog of the Saccharomyces cerevisiae mitochondrial iron transporter, in C. neoformans var. grubii. A strain expressing an Mrs3/4-GFP fusion protein was generated, and the mitochondrial localization of the fusion protein was confirmed. Moreover, a mutant lacking the MRS3/4 gene was constructed; this mutant displayed significantly reduced mitochondrial iron and cellular heme accumulation. In addition, impaired mitochondrial iron-sulfur cluster metabolism and altered expression of genes required for iron uptake at the plasma membrane were observed in the mrs3/4 mutant, suggesting that Mrs3/4 is involved in iron import and metabolism in the mitochondria of C. neoformans. Using a murine model of cryptococcosis, we demonstrated that an mrs3/4 mutant is defective in survival and virulence. Taken together, our study suggests that Mrs3/4 is responsible for iron import in mitochondria and reveals a link between mitochondrial iron metabolism and the virulence of C. neoformans.

• Korean Journal of Materials Research
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• v.22 no.1
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• pp.16-23
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• 2012

Research into the development of high strength (1 GPa) and superior formability, such as total elongation (10%), and stretch-flangeability (50%) in hot-rolled steel was conducted with a thermomechanically controlled hot-rolling process. To improve the overall mechanical properties simultaneously, low-carbon steel using precipitation hardening of Ti-Nb-V multimicroalloying elements was employed. And, ideal microstructural characteristics for the realization of balanced mechanical properties were determined using SEM, EBSD, and TEM analyses. The developed steel, 0.06C-2.0Mn-0.5Cr-0.2(Ti + Nb + V), consisted of ferrite as the matrix phase and second phase of granular bainite with fine carbides (20-50 nm) in both phases. The significant factor of the microstructural characteristics that affect stretch-flangeability was found to be the microstructural homogeneity. The microstructural homogeneity, manifest in such characteristics as low localization of plastic strain and internally stored energy, was identified by grain average misorientation method, analyzed by electron backscattered diffraction (EBSD) and hardness deviation between the phases. In summar, a hot-rolled steel having a composition 0.06C-2.0Mn-0.5Cr-0.2(Ti + Nb + V) demonstrated a tensile strength of 998 MPa, a total elongation of 19%, and a hole expansion ratio of 65%. The most important factors to satisfy the mechanical property were the presence of fine carbides and the microstructural homogeneity, which provided low hardness deviation between the phases.