• The Korean Journal of Physiology and Pharmacology
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• v.7 no.1
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• pp.29-31
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• 2003

It is well known that different expression of Apo-1/Fas (CD95) plays important roles in various tumors and hepatocellular carcinoma (HCC) pathogenesis. Apo-1/Fas mediated apoptosis is one of the important pathways of apoptosis and is known to mediate apoptotic cell death by fas ligand (FasL). To examine the possible relationship between Apo-1/Fas gene polymorphism and HCC susceptibility, MvaI restriction fragment length polymorphism (RFLP) of Apo-1/Fas gene was examined in 94 Korean HCC patients and 240 control subjects. No statistically significant difference in the genotypic distribution and allelic frequencies was found between the control and the HCC. It is, therefore, concluded that Apo-1/Fas gene polymorphism is not associated with HCC susceptibility. Further studies are needed in order to clarify the relationships between genotypes of Apo-1/Fas gene and HCC pathogenesis.

• The Korean Journal of Mycology
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• v.22 no.3
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• pp.254-259
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• 1994

The ever increasing demand for energy and the shortage of resources all over the world have generated interest in recycling renewable sources such as lignocelluloses which otherwise would go to waste and cause environmental pollution. Lignin is the incrustation material for cellulose and hemicellulose, therefore, cellulose and hemicellulose are not easily degraded. Recycling lignocellulosic wastes as agricultural material are benefit to everybody and everything. In order to improve ligninase and laccase production of Phanerochaete chrysosporium, BKM-F-1767 and Ceriporiopsis subvermispora, FP 90031-SP, were compared. The ligninase activity of P. chrysosporium was maximum on day 4.5 of shaking culture at 150 rpm 2.5 cm in a back and forth cycle. The laccase activity of C. subvermispora was maximum on day 5.5 for 2% malt extract+0.1% yeast extract+0.1% Tween 20+6 mM Benzyl alcohol culture medium at stationary state.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.1
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• pp.85-91
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• 2009

This paper proposes a simulation method of the internal winding fault to calculate the short-circuit current, electromagnetic force and vibration mode in a distribution power transformer by using FEM program(FLUX2D) and analytic algorithm. A usage of the Transfer matrix method is also presented for the vibration mode analysis of the cable-type winding of power transformer. The equations of the winding are approximated by the series expansions of the distributed mass mode and Timoshenko's beam theory. The simulation examples are provided for the cable type winding of the transformer(22.9[kV]/220[V], 1,000[kVA]) to verify the method. The proposed Transfer Matrix Method is also verified by the ANSYS program for the vibration mode of the transformer winding. The method presented may serve as one of the useful tools in the electromagnetic force and vibration analysis of the transformer winding under the short circuit condition.

• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.5
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• pp.424-431
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• 2007

This thesis proposed H-Bridge Multi-Level Inverter for Fluidized Bed Combustion Boiler Secondary Air Fan in 200MW thermal power plant. The adjustable speed drive systems improve the efficiency in lightly load condition and extend the life span of motor by limiting the over current at starting. H-Bridge Multi-level Inverter is composed of the several series low voltage power cell inverters, which have the independent isolated do link, in each phase. KEPRI(Korea Electric Power Research Institute) has successfully completed to develop, install, and commission H-Bridge Multi-level Inverter(6.6kV, 1MVA). This thesis gives a full detail about H-Bridge Multi-level Inverter, proposed boiler DCS(Distributed Control System) logic, and commissioning test result.

• Journal of Korea Society of Industrial Information Systems
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• v.25 no.1
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• pp.25-30
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• 2020

Three-phase multi-layer high temperature superconducting coaxial (TPMHTSC) cable is being actively studied due to advantages such as the reduction of the amount of superconducting wire usage and the miniaturization of the cable. The electrical characteristics of TPMHTSC cables differ from those of conventional superconducting cables, so sufficient analysis is required to apply them to the actual system. In this paper, the authors modeled 22.9 kV, 60 MVA TPMHTSC cable and analyzed the transient characteristics using a PSCAD/EMTDC-based simulation. As a result, when a fault current flows in TPMHTSC cable, most of the fault current is bypassed through the copper former layers. At this time, the total cable temperature increased by about 5 K. Through this study, we can verify the reliability of the TPMHTSC cable against the transient state, and it can be helpful for the practical application of the cable in the future.

• Journal of IKEEE
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• v.24 no.1
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• pp.216-224
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• 2020

This paper proposes an impedance design method of the test device for evaluating Low Voltage Ride Through(LVRT) and High Voltage Ride Through(HVRT) functions. The LVRT/HVRT test device should have ability to generate the fault voltage specified in the grid code for a certain period and to limit the magnitude of the fault current with the design specification. In this paper, the impedance design method for auto transformer is proposed based on a equivalent model of a tap-change auto-transformer during LVRT/HVRT operation. In addition, to generate various fault voltages required the LVRT/HVRT test, tap impedance design in the auto transformer is considered. To verify the validity of the proposed design method, the design process of the 10MVA LVRT/HVRT test device was conducted and the design results was verified through simulation models.

• Journal of Ginseng Research
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• v.42 no.3
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• pp.277-287
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• 2018

Background: Temperature is an essential condition in red ginseng processing. The pharmacological activities of red ginseng under different steam temperatures are significantly different. Methods: In this study, an ultrahigh-performance liquid chromatography quadrupole time-of-flight tandem mass spectrometry was developed to distinguish the red ginseng products that were steamed at high and low temperatures. Multivariate statistical analyses such as principal component analysis and supervised orthogonal partial least squared discrimination analysis were used to determine the influential components of the different samples. Results: The results showed that different steamed red ginseng samples can be identified, and the characteristic components were 20-gluco-ginsenoside Rf, ginsenoside Re, ginsenoside Rg1, and malonyl-ginsenoside Rb1 in red ginseng steamed at low temperature. Meanwhile, the characteristic components in red ginseng steamed at high temperature were 20R-ginsenoside Rs3 and ginsenoside Rs4. Polar ginsenosides were abundant in red ginseng steamed at low temperature, whereas higher levels of less polar ginsenosides were detected in red ginseng steamed at high temperature. Conclusion: This study makes the first time that differences between red ginseng steamed under different temperatures and their ginsenosides transformation have been observed systematically at the chemistry level. The results suggested that the identified chemical markers can be used to illustrate the transformation of ginsenosides in red ginseng processing.

• Journal of Microbiology and Biotechnology
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• v.29 no.10
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• pp.1656-1664
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• 2019

Isoprene has the potential to replace some petroleum-based chemicals and can be produced through biological systems using renewable carbon sources. Ralstonia eutropha can produce value-added compounds, including intracellular polyhydroxyalkanoate (PHA) through fatty acid and lipid metabolism. In the present study, we engineered strains of R. eutropha H16 and examined the strains for isoprene production. We optimized codons of all the genes involved in isoprene synthesis by the mevalonate pathway and manipulated the promoter regions using pLac and pJ5 elements. Our results showed that isoprene productivity was higher using the J5 promoter ($1.9{\pm}0.24{\mu}g/l$) than when using the lac promoter ($1.5{\pm}0.2{\mu}g/l$). Additionally, the use of three J5 promoters was more efficient ($3.8{\pm}0.18{\mu}g/l$) for isoprene production than a one-promoter system, and could be scaled up to a 5-L batch-cultivation from a T-flask culture. Although the isoprene yield obtained in our study was insufficient to meet industrial demands, our study, for the first time, shows that R. eutropha can be modified for efficient isoprene production and lays the foundation for further optimization of the fermentation process.

• Journal of Trauma and Injury
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• v.20 no.1
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• pp.19-25
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• 2007

Purpose: Trauma surgery is not an official medical specialty in the Republic of Korea (South Korea). Thus, a trauma victim transported to an emergency room (ER) is resuscitated and surveyed by an intern, a resident, or an emergency physician (EP) at first. Currently an operative management is decreasing because of multiple factors. Nevertheless, trauma surgery is the key for some patients. Does the EP's treatment in the ER delay the surgeon's emergency operation? Methods: A retrospective study was performed for trauma victims who underwent trauma surgery from March 2004 to February 2005 in a local emergency center of Daegu-city. We reviewed the medical records and analyzed the trauma victim's age, sex, cause of injury, method of transport, time from the trauma to the operation, EP's treatment, surgical department, mortality, and injury severity score (ISS). Results: Of the 223 trauma victims included in this study, males were predominant (83.4%). The mean age was 37.98 years of age. The main Causes of trauma were trauma NOS (not otherwise specified) and motor vehicle accidents (MVA). The main methods of transport was privately owned automobile. The mean time from trauma to operation was 617.46 min. The mean ISS was 7.67. Trauma surgery with the EP's treatment group included 40 trauma victims with higher ISS, and the time from trauma to operation was shorter than it was for the 183 trauma victims not in that group. Conclusion: The EP's treatment of high-ISS multiple-injury trauma victims can shorten the time from trauma to trauma surgery and will help the surgical department treatment. In the trauma care system of the Republic of Korea, and increased role should be encouraged for emergency physician.

• BMB Reports
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• v.40 no.6
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• pp.861-869
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• 2007

The enzyme 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR; EC1.1.1.34) catalyzes the first committed step of isoprenoids biosynthesis in MVA pathway. Here we report for the first time the cloning and characterization of a full-length cDNA encoding HMGR (designated as CgHMGR, GenBank accession number EF206343) from hazel (Corylus avellana L. Gasaway), a taxol-producing plant species. The full-length cDNA of CgHMGR was 2064 bp containing a 1704-bp ORF encoding 567 amino acids. Bioinformatic analyses revealed that the deduced CgHMGR had extensive homology with other plant HMGRs and contained two transmembrane domains and a catalytic domain. The predicted 3-D model of CgHMGR had a typical spatial structure of HMGRs. Southern blot analysis indicated that CgHMGR belonged to a small gene family. Expression analysis revealed that CgHMGR expressed high in roots, and low in leaves and stems, and the expression of CgHMGR could be up-regulated by methyl jasmonate (MeJA). The functional color assay in Escherichia coli showed that CgHMGR could accelerate the biosynthesis of $\beta$-carotene, indicating that CgHMGR encoded a functional protein. The cloning, characterization and functional analysis of CgHMGR gene will enable us to further understand the role of CgHMGR involved in taxol biosynthetic pathway in C. avellana at molecular level.