• Journal of Microbiology and Biotechnology
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• v.31 no.3
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• pp.419-428
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• 2021

To efficiently recycle GH78 thermostable rhamnosidase (TpeRha) and easily separate it from the reaction mixture and furtherly improve the enzyme properties, the magnetic particle Fe3O4-SiO2-NH2-Cellu-ZIF8 (FSNcZ8) was prepared by modifying Fe3O4-NH2 with tetraethyl silicate (TEOS), microcrystalline cellulose and zinc nitrate hexahydrate. FSNcZ8 displayed better magnetic stability and higher-temperature stability than unmodified Fe3O4-NH2 (FN), and it was used to adsorb and immobilize TpeRha from Thermotoga petrophilea 13995. As for properties, FSNcZ8-TpeRha showed optimal reaction temperature and pH of 90℃ and 5.0, while its highest activity approached 714 U/g. In addition, FSNcZ8-TpeRha had better higher-temperature stability than FN. After incubation at 80℃ for 3 h, the residual enzyme activities of FSNcZ8-TpeRha, FN-TpeRha and free enzyme were 93.5%, 63.32%, and 62.77%, respectively. The organic solvent tolerance and the monosaccharides tolerance of FSNcZ8-TpeRha, compared with free TpeRha, were greatly improved. Using naringin (1 mmol/l) as the substrate, the optimal conversion conditions were as follows: FSNcZ8-TpeRha concentration was 6 U/ml; induction temperature was 80℃; the pH was 5.5; induction time was 30 min, and the yield of products was the same as free enzyme. After repeating the reaction 10 times, the conversion of naringin remained above 80%, showing great improvement of the catalytic efficiency and repeated utilization of the immobilized α-L-rhamnosidase.

• Proceedings of the CALSEC Conference
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• 1998.10a
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• pp.141-148
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• 1998

ㆍ Design Creation is More Efficient ㆍ Large Shared Body of Knowledge Created and Maintained...Reducing Training Time, Re-Training, Costs and Design Efforts. ㆍ Electronic Data Easier to Exchange and Integrate. An Overall Increase in Efficiency, Savings and Competitiveness Will be Achieved(omitted)

• Bulletin of the Korean Chemical Society
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• v.26 no.3
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• pp.377-378
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• 2005

• Bulletin of the Korean Chemical Society
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• v.32 no.2
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• pp.693-696
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• 2011

• Applied Biological Chemistry
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• v.33 no.2
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• pp.174-176
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• 1990

Oxidation of artemisinic acid was attempted with chromium trioxide-pyridine complex. Epi-Deoxyarteannuin B was formed almost quantitatively, while expected keto artemisinic acid was not the major product. The physical and spectral data of the product are presented(Received March 9, 1990, Accepted May 25, 1990)

• Proceedings of the Korean Society of Potoscience Conference
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• 2005.06a
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• pp.85-85
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• 2005

• BMB Reports
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• v.44 no.7
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• pp.446-451
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• 2011

The conversion of fibroblasts into osteoblasts requires the activation of key signaling pathways, including the BMP pathway. Although Runx2 is known to be a component of the BMP pathway, the combination of Runx2 and BMP2 has not yet been examined with respect to the conversion of fibroblasts into osteoblasts. Here, human ligamentum flavum (LF) fibroblast-like cells from six patients were tested for their conversion into osteoblasts using adenoviruses expressing Runx2 or BMP2. The forced expression of Runx2 or BMP2 in primary cultured LF cells resulted in a variety of proliferation and differentiation behaviors. Combined treatment of BMP2 plus Runx2 resulted in better osteoblastic differentiation than treatment with either component alone. These results indicate that the Runx2 and BMP2 pathways possess both common and independent target genes. Collectively, Runx2 plus BMP2 mediated efficient conversion of fibroblast-like LF cells into osteoblast-like cells, suggesting the possible use of these components for clinical applications such as spinal fusion.

• Korean Chemical Engineering Research
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• v.54 no.4
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• pp.519-526
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• 2016

Biomass derived jet fuel is proven as a potential alternative for the currently used fossil oriented energy. The efficient production of jet fuel precursor with special molecular structure is prerequisite in producing biomass derived jet fuel. We synthesized a new jet fuel precursor containing branched $C_{15}$ framework by aldol condensation of furfural (FA) and ethyl levulinate (EL), where the latter of two could be easily produced from lignocellulose by acid catalyzed processes. The highest yield of 56% for target jet fuel precursor could be obtained at the optimal reaction condition (molar ratio of FA/EL of 2, 323 K, 50 min) by using KOH as catalyst. The chemical structure of $C_{15}$ precursor was specified as (3E, 5E)-6-(furan-2-yl)-3-(furan-2-ylmethylene)-4-oxohex-5-enoic acid ($F_2E$). For stabilization, this yellowish solid precursor was hydrogenated at low temperature to obtain C=C bonds saturated product, and the chemical structure was proposed as 4-oxo-6-(tetrahydrofuran-2-yl)-3-(tetrahydrofuran-2-yl)-methyl hexanoic acid ($H-F_2E$). The successful synthesis of the new jet fuel precursors showed the significance that branched jet fuel could be potentially produced from biomass derived FA and EL via fewer steps.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.11B
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• pp.1596-1606
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• 2010

In this paper, we present a new analytical model that can precisely estimate the blocking performance of wavelength-routed WDM networks with sparse-partial-limited wavelength conversion (SPLWC). The proposed model accounts for the two sources of call blocking in a wavelength converter: range blocking originated from the limited conversion range of a wavelength converter; and capacity blocking induced from the limited number of wavelength converters. Based on the proposed model, we also present a new converter placement algorithm that minimizes the amount of wavelength conversion capability, while satisfying the given constraint on the network-wide blocking probability. From the numerical results obtained from the EON, we demonstrate that the blocking probability of the analytical model closely matches with that of the simulation. We also show that, by efficiently combining the existing sparse, partial, and limited wavelength conversion, the SPL WC can achieve the required blocking performance with the least amount of wavelength conversion cost.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.8
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• pp.61-66
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• 2008

Recently, portable devices which require small area and low power consumption employ applications using 3D graphics such as 3D games and 3D graphical user interfaces. We propose an efficient clipping engine algorithm which is suitable in 3D graphics pipeline. The clipping operation is divided into two steps: one is the selection process in the transformation engine and the other is the pixel clipping process in the scan conversion unit. The clipping operation is possible with addition of simple comparator. The clipping for the Y-axis is achieved in the edge walk stage and that for the X and Z-axis is performed in the span processing. The proposed clipping algorithm reduces the operation cycles and the area of of 3D graphics pipelines. We designed a 3D graphics pipeline with the proposed clipping algorithm using Verilog-HDL and verifies the operation using an FPGA.