• Korean Journal of Agricultural and Forest Meteorology
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• v.8 no.3
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• pp.174-182
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• 2006

This study was to clarify the effects of forest stand changes on hydrological components of evapotranspiration and discharge. The forest-hydrological experimental stations in Gwangneung and Yangju, Gyeonggido near metropolitan Seoul have been operated by the Korea Forest Research Institute since 1979 to clarify the effects of forest types and practices on the water resources and nutrient cycling and soil loss. The hydrological regime of the forested catchments may change as forests develop. The ranges of change may be different depending on forest types. Evapotranspiration can be estimated to 679mm, 580mm and 368mm in planted young coniferous (PYC), natural old-growth deciduous (NOD) and rehabilitated young mixed (RYM), respectively. The slope of the discharge-duration curve shows the capacity of discharge control in a specific catchment. The slope tended to be steeper in RYM than NOD, the better forest condition. The slope in RYM became more gentle as the forest stand developed. Forests can modulate peak flows through interception, evapotranspiration and soil storage opportunity. PYC and RYM showed 100 and 50mm of threshold rainfall for modulating peak flows, respectively. The deciduous forest did not represent sudden changes of peak flow rates to rainfall, even 200 mm rainfall Forest development in PYC may play an important role in modulation of peak flows because peak flow rates reduced after 10 years.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.1240-1246
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• 2006

Generally, there are two types of main factors to affect output power quality of a auxiliary power supply an EMU(electric multiple unit). One is a voltage flicker by amplitude modulation of short time and air compressors. The other is repetitive motion of large capacity motor such as air compressors, HVAC unit etc. in main factors. This paper compared two kinds of fluorescent lamp, 32W (after remodeling interior) and 40W(before remodeling interior) and measured the light output varying input power(AC220V) for a flicker phenomenon related power supply of lamps in EMU. Also, we analyzed a flicker considering EMU operating time and density in order to grasp main factors of a load change to cause a voltage change. As a results of test, a 40W fluorescent lamp was more insensitive with 20.26% degree an eye recognition degree sides about changes of the input power and lower with 19.9% voltage side generating flicker compare with fluorescent lamp 32W. Also, we confirmed the fact which the fluorescent lamp flicker was generated by varying fluorescent lamp output voltage when the commercial EMU was in high driving density and at the busy time. Additionally, we confirmed the frequency band which an EMU passenger could feel sensitively blinking of a fluorescent lamp was visually $8Hz{\sim}15Hz$.

• Journal of Life Science
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• v.17 no.6 s.86
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• pp.748-755
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• 2007

The in vitro activity of ST1571, an inhibitor of the Abl group of protein-tyrosine kinases, alone or in combination with camptothecin (CPT), a specific topoisomerase I inhibitor, was evaluated against human cancer cells with different metastatic capacity and drug resistance potency. These cell lines showed different sensitivity to ST157 on growth inhibition, and the expression of DNA-dependent protein kinase (DNA-PK), which interacts constitutively with c-Abl, was significantly decreased in drug sensitive CEM and MCF-7 cells and poorly metastatic PC3 and KMl2 cells as compared with that of multidrug resistant CEM/MDR and MCF-7/MDR cells and highly metastatic PC3-MM2 and KM/L4a cells, respectively. These results suggest differential modulation of DNA-PK by ST1571 treatment in drug resistance and metastatic degree dependent manner. We showed that CPT as well as ST1571 significantly inhibits the expression of DNA-PK. The combined treatment with ST15fl and CPT revealed synergistic effect, and the effect was accompanied by inhibition of cell proliferation due to significant reduced expression of DNA-PK components, which resulted in CPT sensitizes human cancer cells resistant to ST1571. Therefore, the results of our study suggested that the suppression of DNA-PK using combination of ST1571 and CPT could be a novel molecular target for against drugresistant and metastatic cancer cells.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.3
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• pp.317-329
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• 1998

In this paper, we have analyzed the packet error probability of DS/CDMA-Trellis Coded QPSK modulation signal with MRC(Maximum Ratio Combining) diversity reception in Rician fading, multi-user interferences and multipath channel. And then we have evaluated the performance and capacity of DS/CDMA-Trellis Coded QPSK system using the MRC diversity reception as a function of direct power to indirect power ratio ($K_R$), the number of diversity branch(M), the number of multi-user(U), PN chip rate(PN), the number of multipath channel($L_P$), and packet length(PL). From the results, we know that the coding gain of DS/CDMA-Trellis Coded QPSK system with 2 branch MRC diversity is about 6 dB against uncoded DS/CDMA BPSK system with 2 branch MRC diversity in Rician fading ($K_R=6dB), 5 multi-user interferences, and 3 multipath channel. And, we know that coded QPSK signal designed for the AWGN channel also perform well on a Rician fading channel with MRC diversity reception. Consequently, we expected that proposed system structure is reliable to the wireless data communication system in Rician fading, multi-user interferences, and multipath channel.

• Childhood Kidney Diseases
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• v.14 no.1
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• pp.32-41
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• 2010

Purpose : Glomerulonephropathy (GN) often manifests as proteinuria and progresses to chronic renal failure without specific therapy. Mesenchymal stem cell (MSC) has been tried as a therapeutic agent in experimental GN, and previous studies showed that administration of MSC concomitantly to the insult inducing GN or via intra-renal administration ameliorated proteinuria. The purpose of this study was to test the therapeutic potential of MSC administered via intravenous route at the time of clinically evident proteinuria. Methods : MSCs were administered intravenously via tail vain into the mice with adriamycin (ADR) induced nephropathy (ADR-GN), two weeks after ADR injection when massive proteinuria was evident. To test the capacity of MSC modulate the cytokine production in the inflammatory milieu, the concentrations of IFN-$\gamma$ and IL-10 were measured in the supernatant of in vitro mixed lymphocyte culture (MLC) with or without additional MSC. Results : MSCs administered intravenously into the proteinuric mice with ADR-GN accelerated the recovery of this experimental GN with disappearance of proteinuria in two weeks when the saline treated (control) mice still showed significant proteinuria. The mice treated with MSC also had a tendency of better survival. Addition of MSC decreased IFN-$\gamma$ and increased IL-10 in the supernatant of MLC. Conclusion : This study showed that MSC had a therapeutic potential even when administered in a more clinically relevant setting into a proteinuric glomerulonephropathy model. Further study to verify the mechanism and long-term safety of this phenomenon is required.

• Journal of Animal Environmental Science
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• v.18 no.sup
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• pp.55-64
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• 2012

We investigated the effect of the clay mineral fortified with complex trace elements by specific fermentation microbes on growth performance and a quality of pork in this study. For the declared experimental animal, 80 heads of crossbred with Large White and Yorkshire were randomly splitted into a control group and a test group. Each group were assigned with 4 replicates and 10 heads of each replicate. When 0.3% of the fermentation product of the clay mineral (FCM) was added into feed stuff and fed for 9 weeks of experimental feeding period, the results of the feed intake, weight gains, pH of carcass, lightness of meat color, and brightness of the muscle semimembranosus were similar to those of the control group. However, dressing percentage, reddishness of carcass, and water holding capacity were improved, respectively, as much as 2.7%, 12%, and 10%, and reduced by 6% in cooking loss. In order to investigate the immune modulatory effect of fermented clay mineral, pheripheral blood mononuclear cells (PBMC) were isolated and Immune modulatory parameters were measured. The proliferation activity of PBMC from pigs fed the fermented clay mineral were significantly increased compared to control group pigs, and also those results were more clearly observed as activated with lipopolysaccharide and concanavaline A. The secretion of TNF-${\alpha}$ of the FCM group pigs showed an increasing tendency. Therefore it was suggested that the feeding of FCM which was high in cation metathesis and the value of infrared ray, activated the immune responses, and thus the production of the environment-friendly high quality pork without the use of antibiotics would be possible.

• Nutrition Research and Practice
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• v.13 no.4
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• pp.302-309
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• 2019

BACKGOURND/OBJECTIVES: Vascular inflammation is an important feature in the atherosclerotic process. Recent studies report that leaves and branches of Carpinus turczaninowii (C. turczaninowii) have antioxidant capacity and exert anti-inflammatory effects. However, no study has reported the regulatory effect of C. turczaninowii extract on the arterial inflammatory response. This study therefore investigated modulation of the arterial inflammatory response after exposure to C. turczaninowii extract, using human aortic vascular smooth muscle cells (HAoSMCs). MATERIALS/METHODS: Scavenging activity of free radicals, total phenolic content (TPC), cell viability, mRNA expressions, and secreted levels of cytokines were measured in LPS-stimulated (10 ng/mL) HAoSMCs treated with the C. turczaninowii extract. RESULTS: C. turczaninowii extract contains high amounts of TPC ($225.6{\pm}21.0mg$ of gallic acid equivalents/g of the extract), as well as exerts time-and dose-dependent increases in strongly scavenged free radicals (average $14.8{\pm}1.97{\mu}g/mL$ $IC_{50}$ at 40 min). Cell viabilities after exposure to the extracts (1 and $10{\mu}g/mL$) were similar to the viability of non-treated cells. Cytokine mRNA expressions were significantly suppressed by the extracts (1 and $10{\mu}g/mL$) at 6 hours (h) after exposure. Interleukin-6 secretion was dose-dependently suppressed 2 h after incubation with the extract, at $1-10{\mu}g/mL$ in non-stimulated cells, and at 5 and $10{\mu}g/mL$ in LPS-stimulated cells. Similar patterns were also observed at 24 h after incubation with the extract (at $1-10{\mu}g/mL$ in non-stimulated cells, and at $10{\mu}g/mL$ in the LPS-stimulated cells). Soluble intracellular vascular adhesion molecules (sICAM-1) secreted from non-stimulated cells and LPS-stimulated cells were similarly suppressed in a dose-dependent manner after 24 h exposure to the extracts, but not after 2 h. In addition, sICAM-1 concentration after 24 h treatment was positively related to IL-6 levels after 2 h and 24 h exposure (r = 0.418, P = 0.003, and r = 0.524, P < 0.001, respectively). CONCLUSIONS: This study demonstrates that C. turczaninowii modulates the arterial inflammatory response, and indicates the potential to be applied as a therapeutic use for atherosclerosis.

• Animal Bioscience
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• v.34 no.3_spc
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• pp.393-404
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• 2021

Objective: This study compared the catechin composition of different tea byproducts and investigated the effects of dietary supplementation with green tea byproducts on the accumulation of abdominal fat, the modulation of lipid metabolism, and the inflammatory response in red feather native chickens. Methods: Bioactive compounds were detected, and in vitro anti-obesity capacity analyzed via 3T3-L1 preadipocytes. In animal experiments, 320 one-day-old red feather native chickens were divided into 4 treatment groups: control, basal diet supplemented with 0.5% Jinxuan byproduct (JBP), basal diet supplemented with 1% JBP, or basal diet supplemented with 5×106 colony-forming unit (CFU)/kg Bacillus amyloliquefaciens+5×106 CFU/kg Saccharomyces cerevisiae (BA+SC). Growth performance, serum characteristics, carcass characteristics, and the mRNA expression of selected genes were measured. Results: This study compared several cultivars of tea, but Jinxuan showed the highest levels of the anti-obesity compound epigallocatechin gallate. 3T3-L1 preadipocytes treated with Jinxuan extract significantly reduced lipid accumulation. There were no significant differences in growth performance, serum characteristics, or carcass characteristics among the groups. However, in the 0.5% JBP group, mRNA expression of fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC) were significantly decreased. In the 1% JBP group, FAS, ACC and peroxisome proliferator-activated receptor γ levels were significantly decreased. Moreover, inflammation-related mRNA expression levels were decreased by the addition of JBP. Conclusion: JBP contained abundant catechins and related bioactive compounds, which reduced lipid accumulation in 3T3-L1 preadipocytes, however there was no significant reduction in abdominal fat. This may be due to a lack of active anti-obesity compounds or because the major changes in fat metabolism were not in the abdomen. Nonetheless, lipogenesis-related and inflammation-related mRNA expression were reduced in the 1% JBP group. In addition, dietary supplementation with tea byproducts could reduce the massive amount of byproducts created during tea production and modulate lipid metabolism and the inflammatory response in chickens.

• Journal of IKEEE
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• v.25 no.2
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• pp.399-407
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• 2021

This paper proposes the DC-link voltage design method of Type 4 wind turbine that minimizes power loss and satisfies the High Voltage Ride Through(HVRT) function requirements of the transmission system operator. The Type 4 wind turbine used for large-capacity offshore wind turbine consists of the Back-to-Back converter in which the converter linked to the power grid and the inverter linked to the wind turbine share the DC-link. When the grid high voltage fault occurs in the Type 4 wind turbine, if the DC-link voltage is insufficient compared to the fault voltage level, the current controller of the grid-side converter can't operate smoothly due to over modulation. Therefore, to satisfy the HVRT function, the DC-link voltage should be designed based on the voltage level of high voltage fault. However, steady-state switching losses increase further as the DC-link voltage increases. Therefore, the considerations should be included for the loss to be increased when the DC-link voltage is designed significantly. In this paper, the design method for the DC-link voltage considered the fault voltage level and the loss is explained, and the validity of the proposed design method is verified through the HVRT function simulation based on the PSCAD model of the 2MVA Type 4 wind turbine.

• Journal of Environmental Health Sciences
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• v.49 no.1
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• pp.22-29
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• 2023

Background: The existing research results on the combined toxicity of these pollutants using mammals, such as rodents, are insufficient, especially in relation to changes in the immune system. Objectives: This study aims at evaluating the cellular immune response to PE-MPs solely or when combined with Pb, which possess excellent adsorption capacity with PE-MPs and is commonly co-exposed in our daily lives. Methods: The study investigated the cellular immune function of 9-week ICR mice with 28 days exposure to PE-MPs (2 mg/mouse/day) and Pb (0.1 mM in distilled water) individually and in combination. PE-MPs were administered via gastric intubation while the lead intake was conducted via the oral drinking water route. Cellular immunity was evaluated by analyzing the production for T_H1 cytokines namely, TNF-α and IFN-𝛾 and T_H2 cytokines, IL-4 and IL-6 in culture supernatants from polyclonally activated splenic mononuclear cells ex vivo. Results: Both the PE-MPs only and the PE-MPs+Pb exposure group revealed an increased T_H1 response with elevated TNF-α and IFN-𝛾 levels and downregulated T_H2 response with low IL-4, and IL-6 production levels compared to the control group. Furthermore, an increased IFN-𝛾/IL-4 ratio was found in the PE-MPs only and PE-MPs+Pb exposure groups, which indicated the skewedness to T_H1 response. Meanwhile, reduced blood hemoglobin levels and increased levels of IL-4, the dominant T_H2 cytokine in the Pb-only exposure group, were observed. Conclusions: Our current findings on the predominance of T_H1 immune response in the PE-MPs and PE-MPs+Pb groups suggest that PE-MPs could be responsible for the predominant induction of the cellular immune changes. This finding could be used as an important landmark in research related to T_H1 predominance, such as autoimmune diseases. It suggests that additional research on immune modulation using longer exposure durations or the same exposure route is required to elucidate stronger findings.