• Design & Manufacturing
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• v.11 no.3
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• pp.19-24
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• 2017

In these days, increase requirement of TEM (Transmission Electro Microscope) in not only scientific field but also industrial field. Because TEM can measure inner-structure of specimen a variety of materials like metal, bio. etc. When use TEM, specimen should be thin about 50nm. So making for thin specimen, use Ion milling device that include specimen holder. The holder generally made of Aluminium Aluminium holder is worn away easily. For this reason, using time of ion milling with aluminum holder is too short. To solve the problem, we replace aluminium holer to molybdenum alloy holder. In this paper, we design molybdenum alloy holer for CAM and modify CAD modeling for effective machining process. So we array a specimen 3 by 4 and setup orientation for one-shot machining process. Next we make a CAM program for machining. we making a decision two machining strategy that chose condition of tool-path method, step-down, step-over. etc. And then conduct machining using CNC milling machining center. To make clear difference between case.1 and case.2, we fixed machining conditions like feed-rate, main spindle rpm, etc. After machining, we confirm the condition of workpiece and analysis the problems case by case. Finally, case.2 work piece that superior than case.1 cutting with WEDM because that method can not ant mechanical effect on workpiece.

• Korean Journal of Environmental Biology
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• v.22 no.3
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• pp.472-477
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• 2004

To study the radiation related gene expression in mutants of Bacillus lentimorbus WJ5 induced by gamm radiation, the simultaneous gene expression was analyzed by DNA micro array. We constructed DNA chips including two thousand randomly digested genome spots of B. lentimorbus WJ5 and compared its quantitative aspect with seven mutants induced by gamma radiation $(^{60}/Co)$. From the cluster analysis of gene expression pattern, totally 408 genes were expressed and 27 genes were significantly upregulated by the gamma radiation in all mutants. Especially, genes involved in repair (mutL, mutM), energy metabolism (acsA, sdhB, pgk, yhjB, citB), protease (npr), and reduction response to oxidative stress (HMM) were simultaneously upregulated. It seems that the induction of the direct and/or indirect repair related genes in mutants induced by gamma radiation could be remarkably different from the adaptive responses against acute exposure to radiation.

• Polymer(Korea)
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• v.26 no.5
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• pp.634-643
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• 2002

Ultrathin film of polyamic acid having benzene and sulfonyloxyimide moieties was prepared using the Langmuir-Blodgett (LB) technique, and then photosensitive polyimide LB film was obtained by the thermal treatment of precursor polyamic acid multilayers at 200$\^{C}$ for 1 hr. The polyamic acid was synthesized by condensation polymerization under THF and pyridine cosolvent. All monomers and polymers were identified through elemental analysis, FT-IR and $^1$H-NMR spectroscopic measurements. The microarray patterning of photosensitive polyimide LB film on a gold substrate was generated with a deep UV lithography technique. The well-characterized monolayer of cytochrome c was immobilized on the microarray patterns using two different self-assembly processes. Physical and electrochemical properties of the self-assembled cytochrome c monolayer were investigated based on cyclic voltammetry and atomic force microscopy (AFM). Also, its application in bioelectronic device was examined.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.275-275
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• 2013

Osteoblast is one of cells related with osseointegration and many research have conducted the adhesion of osteoblast onto the surface of implant. In the osseointegration, biocompatibility of the implant and cell adhesion to the surface are important factors. The researches related to cell adhesion have a direction from micro-scaled surface roughness to nano-scaled surface roughness with advancing nanotechnology. A cell reacts and sense to stimuli from extracellular matrix (ECM) and topography of the ECM [1]. Thus, for better osseointegration, we should provide an environment similar to ECM. In this study, we synthesize TiO2 nanowires using hydrothermal reaction because TiO2 provides inertness to titanium on its surface and enables it used as an implant material for the orthopedic treatment such as fixation of the bone fracture [2]. Ti substrate is immersed into NaOH aqueous solution. The solution are heated at $140{\sim}200^{\circ}C$ for various time (10~720 minutes). After heat treatment, we take out the sample and immerse it into HCl aqueous solution for 1 hour. The acid treated sample is heated again at $500^{\circ}C$ for 3 hours [3]. Then, we culture osteoblast on the TiO2 nanowires. For investigating cell adhesion onto nanostructured surface, we conduct several tests such as MTT assay, ALP (Alkaline phosphatase) activity assay, measuring calcium expression, and so on. These preliminary results of the cell culture on the nanowires are foundation for investigating cell-material interaction especially with nanostructure interaction.

• Biomolecules & Therapeutics
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• v.31 no.1
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• pp.27-39
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• 2023

Extensive research supported the therapeutic potential of curcumin, a naturally occurring compound, as a promising cytokine-suppressive anti-inflammatory drug. This study aimed to investigate the synergistic anti-inflammatory and anti-cytokine activities by combining 6-shogaol and 10-shogaol to curcumin, and associated mechanisms in modulating lipopolysaccharides and interferon-γ-induced proinflammatory signaling pathways. Our results showed that the combination of 6-shogaol-10-shogaolcurcumin synergistically reduced the production of nitric oxide, inducible nitric oxide synthase, tumor necrosis factor and interlukin-6 in lipopolysaccharides and interferon-γ-induced RAW 264.7 and THP-1 cells assessed by the combination index model. 6-shogaol-10-shogaol-curcumin also showed greater inhibition of cytokine profiling compared to that of 6-shogaol-10-shogaol or curcumin alone. The synergistic anti-inflammatory activity was associated with supressed NFκB translocation and downregulated TLR4-TRAF6-MAPK signaling pathway. In addition, SC also inhibited microRNA-155 expression which may be relevant to the inhibited NFκB translocation. Although 6-shogaol-10-shogaol-curcumin synergistically increased Nrf2 activity, the anti-inflammatory mechanism appeared to be independent from the induction of Nrf2. 6-shogaol-10-shogaol-curcumin provides a more potent therapeutic agent than curcumin alone in synergistically inhibiting lipopolysaccharides and interferon-γ induced proinflammatory mediators and cytokine array in macrophages. The action was mediated by the downregulation of TLR4/TRAF6/MAPK pathway and NFκB translocation.

• The Korea Journal of Herbology
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• v.22 no.4
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• pp.253-260
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• 2007

Objectives : Intracerebral hemorrhage (ICH) is characterized by breakdown of blood vessels within the brain parenchyma. Fundamental therapeutic strategies for ICH, particularly those aimed at neuroprotection, have to be established. So in this experiment, the effects of Woowhangchongshim-won, a traditional prescription formula for treating Cerebral Apoplexy in Asian countries, were investigated. Methods : After intraperitoneal injection of chloralhydrate, rats were placed in a stereotaxic frame. ICH was induced by injection of 1 U collagenase type IV and drug was administered orally for 10 days. The molecular profile of cerebral hemorrhage in rat brain tissue was measured using micro array technique to identify up- or down- regulated genes in brain tissue. These genes induced by brain damage were mainly concerned with general metabolic process such as primary metabolic process, cellular metabolic process, macromolecule metabolic process, and biosynthetic process. Results : The number of genes increased in control and not-changed in experiment was 374, and decreased in control and not-changed in experiment was 527. We are concerned with genes that can be recovered by treatment with medicine, it is especially interesting to above types of genes. Conclusions : Upon medicine treatment to the rat having cerebral hemorrhage, expressions of some genes were restored to normal level. Further analysis using protein interaction database identified some key molecules that can be used for elucidation of therapeutical mechanism of medicine in future.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.311-311
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• 2009

Carbon nanotubes (CNTs) belong to an ideal material for field emitters because of their superior electrical, mechanical, and chemical properties together with unique geometric features. Several applications of CNTs to field emitters have been demonstrated in electron emission devices such as field emission display (FED), backlight unit (BLU), X-ray source, etc. In this study, we fabricated a CNT cathode by using filtration processes. First, an aqueous CNT solution was prepared by ultrasonically dispersing purified single-walled CNTs (SWCNTs) in deionized water with sodium dodecyl sulfate (SDS). The aqueous CNT solution in a milliliter or even several tens of micro-litters was filtered by an alumina membrane through the vacuum filtration, and an ultra-thin CNT film was formed onto the alumina membrane. Thereafter, the alumina membrane was solvated by acetone, and the floating CNT film was easily transferred to indium-tin-oxide (ITO) glass substrate in an area defined as 1 cm with a film mask. The CNT film was subjected to an activation process with an adhesive roller, erecting the CNTs up to serve as electron emitters. In order to measure their luminance characteristics, an ITO-coated glass substrate having phosphor was employed as an anode plate. Our field emitter array (FEA) was fairly transparent unlike conventional FEAs, which enabled light to emit not only through the anode frontside but also through the cathode backside, where luminace on the cathode backside was higher than that on the anode frontside. Futhermore, we added a reflecting metal layer to cathode or anode side to enhance the luminance of light passing through the other side. In one case, the metal layer was formed onto the bottom face of the cathode substrate and reflected the light back so that light passed only through the anode substrate. In the other case, the reflecting layer coated on the anode substrate made all light go only through the cathode substrate. Among the two cases, the latter showed higher luminance than the former. This study will discuss the morphologies and field emission characteristics of CNT emitters according to the experimental parameters in fabricating the lamps emitting light on the both sides or only on the either side.

• Journal of Microbiology and Biotechnology
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• v.14 no.6
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• pp.1239-1248
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• 2004

The methylotrophic yeast Hansenula polymorpha has been extensively studied as a model organism for methanol metabolism and peroxisome biogenesis. Recently, this yeast has also attracted attention as a promising host organism for recombinant protein production. Here, we describe the fabrication and evaluation of a DNA chip spotted with 382 open reading frames (ORFs) of H. polymorpha. Each ORF was PCR-amplified using gene-specific primer sets, of which the forward primers had 5'-aminolink. The PCR products were printed in duplicate onto the aldehyde-coated slide glasses to link only the coding strands to the surface of the slide via covalent coupling between amine and aldehyde groups. With the partial genome DNA chip, we compared efficiency of direct and indirect cDNA target labeling methods, and found that the indirect method, using fluorescent-labeled dendrimers, generated a higher hybridization signal-to-noise ratio than the direct method, using cDNA targets labeled by incorporation of fluorescence-labeled nucIeotides during reverse transcription. In addition, to assess the quality of this DNA chip, we analyzed the expression profiles of H. polymorpha cells grown on different carbon sources, such as glucose and methanol, and also those of cells treated with the superoxide­generating drug, menadione. The profiles obtained showed a high-level induction of a set of ORFs involved in methanol metabolism and oxidative stress response in the presence of methanol and menadione, respectively. The results demonstrate the sensitivity and reliability of our arrays to analyze global gene expression changes of H. polymorpha under defined environmental conditions.

• Journal of Convergence for Information Technology
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• v.8 no.5
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• pp.45-50
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• 2018

The functional nanomaterials of fluorescent dye-doped silica nanoparticles(NPs) are applied to bio applications such as bio-labeling of DNA micro-array, and bio-imaging. Organic dye-doped fluorescent silica NPs exhibit excellent bio-compatibility, non-toxic, and highly hydrophilic properties. In this study, organic fluorescent dyes were dissolved in ethanol, and deionized(DI) water. Organic fluorescent dyes were physically adsorbed to silica NPs and chemically doped to silica NPs. The fluorescence characteristics(FLC) was investigated by UV lamp irradiation of 365 nm wavelength. As results, the FLC of dye-doped silica NPs exhibits better than dye-adsorbed silica NPs and the FLC was improved with the increase of concentration of doped-dyes. The fluorescent organic dyes were well dissolved in ethanol than DI water. The photostability of dye-doped silica NPs was superior than pure fluorescent organic dye. The FLC of optimized dye-doped silica NPs would be applied to agent of non-invasive fluorescence bio-imaging in live cell and in vivo.

• Journal of Gastric Cancer
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• v.6 no.3
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• pp.181-188
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• 2006

Purpose: Heregulin is a natural ligand for erbB3 and erbB4. However, very little is known about their roles in the gastric cancer This retrospective study was performed to evaluate the frequencies of heregulin and erbB family protein expression and to compare their expressions with clinicopathologic parameters. Materials and Methods: Immunohistochemical expressions of heregulin and erbB family proteins were examined with tissue micro-array slides. A total of 251 gastric adenocarcinomas were classified as early cancers and advanced cancers and as having and not having lymph node metastases. Results: The positive rates of the heregulin, erbB1, erbB2, erbB3, and erbB4 protein stainings were 64%, 68%, 6%, 88%, and 76%, respectively. Intestinal type gastric adenocarcinomas showed higher expression of heregulin, erbB2, erbB3, and erbB4 proteins. Heregulin and erbB4 proteins showed lower expressions in advanced gastric carcinomas. However, erbB2 protein showed higher expression in advanced gastric carcinomas. The protein expressions of heregulin and erbB family proteins showed no relationship with survival rate. Co-expression groups of heregulin and erbB3 proteins or heregulin and erbB4 proteins showed higher expressions in intestinal type adenocarcinomas and early gastric carcinomas. Conclusion: Heregulin, erbB3, and erbB4 proteins may play a role in the early stage of adenocarcinomas.