• Journal of fish pathology
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• v.27 no.2
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• pp.99-105
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• 2014

Biosensors consist of biochemical recognition agents like antibodies immobilized on the surfaces of transducers that change the recognition into a measurable electronic signal. Here we report a piezoelectric immunosensor made to detect Vibrio vulnificus. A 9MHz AT-cut piezoelectric wafer attached with two gold electrodes of 5mm diameter was used as the transducer of the QCM biosensor with a reproducibility of ${\pm}0.1Hz$ in frequency response. We have tried different approaches to immobilize antibody on the sensor chip. Concerning the orientation of antibody for the best antigen binding capacity, the antibody was immobilized by specific binding to protein G or by cross-linking through hydrazine. In addition, protein G was cross-linked on glutaraldehyde activated immine layer (PEI) or EDC/NHS activated sulfide monolayer (MPA). PEI was found to be more effective to immobilize protein G following glutaraldehyde activation than MPA. However, hydrazine chip showed a better capability to immobilize more IgG than protein G chip and a higher sensitivity. The sensor system was able to detect V. vulnificus in dose dependent manner and was able to detect bacterial cells within 5 minutes by monitoring frequency shifts in real time. The detection limit can be improved by preincubation to enrich the bacterial cell number.

• Journal of Microbiology and Biotechnology
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• v.5 no.5
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• pp.245-249
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• 1995

Expression of the adjacent but divergently transcribed glpD and glpE gene is positively regulated by cAMP-CRP. In this study, we constructed several mutants in which a CRP-binding site is placed at different distances upstream of the glpD promoter. The effect of the spacer length on transcription activation by cAMP-CRP was tested in vivo by $\beta$-galactosidase. The cAMP-CRP complex activated transcription from glpD when bound at a number of positions, all of which lay on the same face of the DNA helix, although the degree of activation varied with the length of the spacer. By contrast, the insertion of spacer length with non-integral turns of the DNA helix extremely inhibited the activation of transcription. The observed transcription activation by cAMP of the glpD promoter was influenced by the distance between the CRP binding site and the transcription start point.

• Animal cells and systems
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• v.1 no.4
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• pp.647-651
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• 1997

We have used a transient expression assay employing Drosophila S2 cells to study the transcriptional repression activity of a 27 amino acid residue-long repression domain FS1 which was generated by a frame-shift in a pair-rule gene, even-skipped of Drosophila melanogaster. In an attempt to define a minimal requirement for the repression activity, we constructed a series of truncation mutant forms of the FS1, fused to a heterologous GAL4 DNA-binding domain, and measured their activities. All of the mutant forms, including the GAL4-FS1 (5-23) which retains the smallest number (19) of amino acid residues of FS1, were found to repress an initiator, a minimal TATA-lacking promoter, in a GAL4-binding-site-dependent manner. These findings suggest that a 19 amino acid residue-long region, rich in proline and leucine residues, is a transcriptional repression domain and may interact with the general transcription machinery.

• Journal of the East Asian Society of Dietary Life
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• v.7 no.3
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• pp.315-324
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• 1997

Physicochemical properties of potato starches oxidized with sodium hypochlorite containing 1.5, 3.0, 4.5, and 6.0% active Cl/g starch at pH 7.0 were examined. Carboxyl group contents of oxidized potato starches were proportional to active chlorine concentration in use and water binding capacity, alkali number, and solubility increased with increasing the degree of oxidation. Blue value and iodine binding property indicated the change of amylose structure by the oxidation. Gelatinization trends obtained from transmittance and DSC thermograms showed that gelatinization temperature was lower as starch was oxidized higher. X-ray diffraction patterns and scanning electron micrographs implied oxidation might occur on the surface amorphous regions of starch granule.

• Bulletin of the Korean Chemical Society
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• v.27 no.11
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• pp.1851-1853
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• 2006

We herein report a new analytical application of XPS to the identification of organic molecules in room temperature ionic liquid for the first time. An organic compound, propargylamine (1), produced in 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][$PF_6$]), which is one of the room temperature ionic liquids (RTILs), via $A^3$ coupling reaction, is characterized by means of x-ray photoelectron spectroscopy (XPS) rather than using conventional organic compound analysis techniques. There are four non-equivalent carbons in RTILs and 1 each. The ratios of normalized integrated areas of the deconvoluted binding energy of core electron of carbon (C1s) peaks are well matched to the number of carbons in those compounds. The binding energies of C1s of the featured carbons in 1, C4 (sp carbons in acetylene group) and C5 ($sp^2$ carbons in benzene ring), are assigned 286.2 and 285.4 eV, respectively. These results will be able to provide an important tool and a new strategy for the analysis of organic molecules

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.340-340
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• 2010

Various structures of vacancy defects in graphene layers and carbon nanotubes have been reported by high resolution transmission electron microscope (HR-TEM) and those arouse an interest of reconstruction processes of vacancy defects. In this talk, we present reconstruction processes of vacancy defects in a graphene and a carbon nanotube by tight-binding molecular dynamics (TBMD) simulations and by first principles total energy calculations. We found that a structure of a dislocation defect with two pentagon-heptagon (5-7) pairs in graphene becomes more stable than other structures when the number of vacancy units is ten and over. The simulation study of scanning tunneling microscopy reveals that the pentagon-heptagon pair defects perturb the wavefunction of electrons near Fermi level to produce the $\sqrt{3}\;{\times}\;\sqrt{3}$ superlattice pattern, which is in excellent agreement with experiment. It is also observed in our tight-binding molecular dynamics simulation that 5-7 pair defects play a very important role in vacancy reconstruction in a graphene layer and carbon nanotubes.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.05a
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• pp.1035-1038
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• 2008

Network mobility (NEMO) has been studied extensively due to its potential applications in military and public transportation. NEMO Basic Support Protocol (NBSP) [1], the current NEMO standard based on mobile IPv6, can be readily deployed using the existing mobile IPv6 infrastructure. However, for Nested network mobility, multi-level tunnel and too many Binding Update packets results in substantial performance overhead, generally known as route sub-optimality, especially in the bottleneck root mobile router (root-MR) and Access Router. In this paper, we propose a route optimization mechanism for nested network mobility management to reduce the overhead of root-MR. In this system, Mobile Router (MR) has a cache that stores Mobile Network Nodes' (MNN) information, Correspondent Nodes' (CN) information for every MNN，and the attachments information with its subnet MRs. Home Agent performs Binding Update with CNs responsible for MRs. Through this mechanism, the number of tunnel is limited between CN and MR and the overhead of root-MR is reduced obviously.

• Journal of the Korean Chemical Society
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• v.68 no.1
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• pp.32-39
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• 2024

Glycerol dehydrogenase (GlyDH) plays a crucial role in the glycerol metabolism pathway by catalyzing the oxidation of glycerol to dihydroxyacetone (DHA). Previous studies of GlyDH have predominantly focused on unraveling the structural features of the active site and its binding interactions with ligand. However, the structural details of GlyDH in complex with both NAD⁺ and the substrate bound have remained elusive. In this study, we present the crystal structures of Klebsiella pneumoniae GlyDH (KpGlyDH) in the absence and presence of NAD⁺ at a resolution of 2.1 Å. Notably, both structures reveal the binding of the substrate, ethylene glycol, to the zinc ion. Interestingly, a significant change in the coordination number of the zinc ion is observed, with three in the absence of NAD⁺ and four in its presence. These findings shed light on the structural aspects of GlyDH and its interactions with NAD⁺ and the substrate.

• Journal of Applied Biological Chemistry
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• v.66
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• pp.186-196
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• 2023

Dyglomera^® is an aqueous ethanol extract derived from the fruit and pods of Dichrostachys glomerata. A previous study has revealed that Dyglomera regulates adipogenesis and lipolysis by modulating AMP-activated protein kinase (AMPK) phosphorylation and increased expression levels of lipolysis-related proteins in white adipose tissue of high fat diet-induced mice and 3T3-L1 adipocyte cells. To further investigate mechanisms of Dyglomera, additional studies were performed using 3T3-L1 cells. Results revealed that Dyglomera downregulated adipogenesis by inhibiting the protein kinase B/mammalian target of rapamycin signaling pathway and reconfirmed that it downregulated gene expression levels of proliferator-activated receptor (PPAR)-γ, CCAAT enhancer binding protein α, sterol-regulation element-binding protein-1c. Dyglomera also reduced adipokines such as tumor necrosis factor alpha, interleukin-1β, and interleukin 6 by regulating leptin expression. Moreover, Dyglomera promoted beige-and-brown adipocyte-related phenotypes and regulated metabolism by increasing mitochondrial number and expression levels of genes such as T-box protein 1, transmembrane protein 26, PR domain 16, and cluster of differentiation 40 as well as thermogenic factors such as uncoupling protein 1, proliferator-activated receptor-gamma co-activator-1α, Sirtuin 1, and PPARα through AMPK activation. Thus, Dyglomera not only can inhibit adipogenesis, but also can promote lipolysis and thermogenesis and regulate metabolism by affecting adipokine secretion from 3T3-L1 adipocytes.

• The Transactions of the Korea Information Processing Society
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• v.5 no.9
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• pp.2395-2403
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• 1998

Memory allocation problem has two independent goals: minimization of number of memories and minimization of number of registers in one memory Our concern is the ordering of the bindings during memory allocation. We formulate and analyze three different memory allocation algorithms b) changing their binding order. It is shown that when we combine these subtasks and solve them simultaneously by heuristic cost function significant savings (up to 20%) can be obtained in the total area of memories.