• The Transactions of the Korean Institute of Power Electronics
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• v.17 no.5
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• pp.438-444
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• 2012

This paper deals with the active and reactive power control of Grid connected system. It was shown that active power and reactive power can be dependently controlled with two individually adaptable parameters. The two parameters are power angle and voltage magnitude. Transient state will occur with active or reactive power reference value variation. This paper presents a new control strategy for active and reactive power control of less interaction and improved transient response. The paper details the control technique by the mathematical and electrical network analysis of the methodology. The performance was verified through computer simulation using MATLAB Simulink and experiment.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.8
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• pp.1351-1359
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• 2007

In this paper, we have studied the power quality(PQ) diagnosis system with the two methods for PQ diagnosis. One to Apply a regulation value in compliance with mathematics calculation, and the other Automatic identification using Neural network algorithm. Neural network algorithm is used for an automatic diagnosis of the PQ. The regulation proposed by IEEE 1159 Working group is applied for the precision of the diagnosis. In order to divide accurate segmentation, the algorithm for a computer training used the back propagation out of several neural network algorithms. We have configured the proto-type sample by using Labview and a programmed Neural Networks Algorithm using with C. And arbitrary electric Signal generated by OMICRON Company's CMC 256-6 for an efficiency test.

• Tuberculosis and Respiratory Diseases
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• v.39 no.4
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• pp.325-333
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• 1992

Background and Methods: To study the effects of corticosteroid (CS) on the parquat (PQ) induced lung injury, serial cellular analyses of bronchoalveolar lavage (BAL) fluid were done with simultaneous histopathologic examination after intraperitoneal injection of PQ on the rats. The sacrificed animals were divided into three groups; control group, PQ group received intraperitoneal injection of 20 mg/kg of PQ, and CS group received daily injection of Methylprednisolone sodium succinate (20 mg/kg) in addition to PQ. Results: 1) Cellular analyses of BAL fluid: The total cell count in the BAL fluid were increased gradually from 6 hours after PQ administration (p<0.05), and was decreased at 3 days after (p<0.05). These changes were mainly due to the effects of PQ on the neutrophil influx (p<0.05). But, the number of macrophage and the percentage of lymphocyte in total cells showed little changes. The CS administration showed the suppression of neutrophil influx in the BAL fluid (p<0.05), but could not show any significant effect on the number of macrophage and lymphocyte. 2) Histopathologic examination: In the PQ group, inflammatory changes especially with prominant neutrophil infiltration were gradually progressed over time. Those changes were found in both alveolar space and interstitium with resultant alveolar structural changes, but subsided from 3 days after. CS suppressed inflammatory changes in the alvolar space and interstitium, especially with decreased infiltration of neutrophil. Conclusion: CS suppressed neutrophil infiltration in the acute lung injury induced by PQ, those findings were ascertained by serial cellular analyses of BAL fluid and histopathologic examination.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.4
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• pp.2189-2198
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• 2014

Paraquat (PQ) is a very effective and widely used herbicide that was commercially introduced in 1962. In this study, instead of using antioxidants like in the past, to inhibit the formation of PQ-induced ROS, we attempted to reduce the oxygen concentration by using non-lethal hypoxia therapy. Therefore, we studied the toxicity of PQ in vivo, analyzed the major effects of ROS on the targeted lung tissue and compared the results with the gross histological changes after the cell protective effect of non-lethal hypoxia therapy. In vivo studies demonstrated that low-concentration oxygen therapy (i.e., 10-12% oxygen) in rats administered with PQ was associated with a higher survival rate than in rats that received only PQ. In vivo non-lethal hypoxia treatment showed better survival and less lung tissue damage. Using a hypoxic/anaerobic incubator with integrated multifaceted molecular analysis, including MDA assay, glutathione assay, and SOD assay, we established an optimal, significantly reduced in vivo non-lethal hypoxia treatment by exploiting the PQ-induced cytotoxicity responses.

• Journal of Microbiology and Biotechnology
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• v.27 no.5
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• pp.1023-1031
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• 2017

The conformational change of cellular prion protein ($PrP^C$) to its misfolded counterpart, termed $PrP^{Sc}$, is mediated by a hypothesized cellular cofactor. This cofactor is believed to interact directly with certain amino acid residues of $PrP^C$. When these are mutated into cationic amino acid residues, $PrP^{Sc}$ formation and prion replication halt in a dominant negative (DN) manner, presumably due to strong binding of the cofactor to mutated $PrP^C$, designated as DN PrP mutants. Previous studies demonstrated that plasminogen and its kringle domains bind to PrP and accelerate $PrP^{Sc}$ generation. In this study, in vitro binding analysis of kringle domains of plasminogen to Q167R DN mutant PrP (PrPQ167R) was performed in parallel with the wild type (WT) and Q218K DN mutant PrP (PrPQ218K). The binding affinity of PrPQ167R was higher than that of WT PrP, but lower than that of PrPQ218K. Scatchard analysis further indicated that, like PrPQ218K and WT PrP, PrPQ167R interaction with plasminogen occurred at multiple sites, suggesting cooperativity in this interaction. Competitive binding analysis using $\small{L}$-lysine or $\small{L}$-arginine confirmed the increase of the specificity and binding affinity of the interaction as PrP acquired DN mutations. Circular dichroism spectroscopy demonstrated that the recombinant PrPs used in this study retained the ${\alpha}$-helix-rich structure. The ${\alpha}$-helix unfolding study revealed similar conformational stability for WT and DN-mutated PrPs. This study provides an additional piece of biochemical evidence concerning the interaction of plasminogen with DN mutant PrPs.

• Korean Journal of Food Science and Technology
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• v.28 no.5
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• pp.865-869
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• 1996

Biological effect of aqueous extracts of 12 plants which showed superoxide dismutase (SOD)-like activity in vitro was evaluated using Drosophila melanogaster. Survival percentage of the flies was a criterion of effect when the flies were exported to paraquat, which generated superoxide anion radical in vivo. When flies were co-administered with paraquat and aqueous extracts of garlic, lettuce, kiwi, and nameko, they showed no defensive effect against of oxygen toxicity. If flies were exposed to 60 mM paraquat after adaptation to feed containing plant extracts with SOD-like activity for 10 days, however, survival percentage of flies fed with phytochemicals was $35{\sim}63%$ while that percentage of flies fed without phytochemical was only 11%. This result indicated that adaptation of flies to plant extracts with SOD-like activity could prevent the flies from oxidative injury. On the other hand, lettuce, kiwi, nameko, onion, persimmon, fern brake and cauliflower showed a reparative effect on an oxidative stress. Dropwort, shiitake, agaric mushroom and broccoli did not show such an effect.

• Journal of Microbiology and Biotechnology
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• v.15 no.3
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• pp.616-625
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• 2005

It is likely that maltose could provide a good substrate for the bacteria in the intestine, when the pathogenic bacteria invade and colonize in human gut. For better understanding of this organism's maltose metabolism, a mutant that was not able to grow with maltose as a sole carbon source was screened from a library of mutants constructed by a random transposon mutagenesis. By a transposon-tagging method, malPQ genes encoding a maltodextrin phosphorylase and a 4-${\alpha}$-glucanotransferase, were identified and cloned from Vibrio vulnificus. The deduced amino acid sequences of malPQ from V. vulnificus were 48 to $91\%$ similar to those of MalP and MalQ reported from other Enterobacteriaceae. Functions of malPQ genes were assessed by the construction of mutants whose malPQ genes were inactivated by allelic exchanges. When maltose was used as the sole carbon source, neither malP nor malQ mutant was able to grow to a substantial level, revealing that the MalP and MalQ are the only enzymes for metabolic utilization of maltose. The malQ mutant exhibited decreased adherence toward intestinal epithelial cells in vitro, but there was no difference in the $LD_{50}s$ of the wild-type and the malQ mutant in mice. Therefore, it appears that MalQ is less important in the pathogenesis of V. vulnificus than would have been predicted by considering maltose as a most common sugar in the intestine, but not completely dispensable for virulence in mice.

• Journal of Life Science
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• v.22 no.3
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• pp.354-359
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• 2012

In our study, we investigated the antioxidant effect of methanol extract from the leaves of Picrasma quassioides (PQ) and Chamaecyparis obtuse (S. et Z.) ENDL (CO). Total polyphenol contents of methanol extracts from PQ and CO varied from 138.3 to $367.52{\mu}g/mg$ and total flavonoid contents varied from 8.12 to $46.41{\mu}g/mg$. Contents of polyphenol and flavonoid in PQ were found to be extremely high. In addition, the methanol extract of PQ had a higher antioxidant activity in both DPPH ($4.79{\mu}g/ml$) and ABTS ($7.21{\mu}g/ml$) compared to other plants (CO). Based on the results of the FRAP assay, PQ showed a value of $8.52{\mu}mol/{\mu}g$ and CO exhibited a value of $1.77{\mu}mol/{\mu}g$. The methanol extracts from the leaves of PQ showed the highest radical-scavenging activity in various antioxidant systems.

• Toxicological Research
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• v.7 no.2
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• pp.151-155
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• 1991

Thirty six crude drug samples have been prepared from different parts of twenty five plants belonging to different families, and antimutangenic activities were studied by using SOS chromotest (E. coli PQ 37). The following crude extracts of PNG medicinal plants which had a appreciable antimutagenic activity against mitomycin C were: Artocarpus communis (stem bark), Cycas circinalis (leaves), Merremia peltata (leaves), Intsia palembanica (leaves), Annona muricata (stem bark), and Artocarpus altilis (root bark).

• 월간 기계설비
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• s.31
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• pp.64-70
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• 1993