• The Korean Journal of Physiology and Pharmacology
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• v.26 no.5
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• pp.347-355
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• 2022

Abdominal aortic aneurysm (AAA) is a life-threatening disorder worldwide. Fibroblast growth factor 21 (FGF21) was shown to display a high level in the plasma of patients with AAA; however, its detailed functions underlying AAA pathogenesis are unclear. An in vitro AAA model was established in human aortic vascular smooth muscle cells (HASMCs) by angiotensin II (Ang-II) stimulation. Cell counting kit-8, wound healing, and Transwell assays were utilized for measuring cell proliferation and migration. RT-qPCR was used for detecting mRNA expression of FGF21 and activating transcription factor 4 (ATF4). Western blotting was utilized for assessing protein levels of FGF21, ATF4, and markers for the contractile phenotype of HASMCs. ChIP and luciferase reporter assays were implemented for identifying the binding relation between AFT4 and FGF21 promoters. FGF21 and ATF4 were both upregulated in Ang-II-treated HASMCs. Knocking down FGF21 attenuated Ang-II-induced proliferation, migration, and phenotype switch of HASMCs. ATF4 activated FGF21 transcription by binding to its promoter. FGF21 overexpression reversed AFT4 silencing-mediated inhibition of cell proliferation, migration, and phenotype switch. ATF4 transcriptionally upregulates FGF21 to promote the proliferation, migration, and phenotype switch of Ang-II-treated HASMCs.

• Nuclear Engineering and Technology
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• v.52 no.3
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• pp.614-620
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• 2020

In a previous study, delayed hydride cracking (DHC) assessment of pressurized water reactor (PWR) spent fuel during dry storage using the threshold stress intensity factor (K_IH) was performed. However, there were a few limitations in the analysis of the cladding properties, such as oxide thickness and mechanical properties. In this study, those models were modified to include test data for irradiated materials, and the cladding creep model was introduced to improve the reliability of the DHC assessment. In this study, DHC susceptibility of PWR spent fuel during dry storage depending on the axial elevation was evaluated with the improved assessment methodology. In addition, the sensitivity of affecting parameters such as fuel burnup, hydride thickness, and crack aspect ratio are presented.

• Journal of Life Science
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• v.28 no.4
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• pp.415-420
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• 2018

Schisandra chinensis (Turcz.) Baill. (omija) is often used in Chinese medicine to treat various human diseases, and is known to possess various bioactive components such as schizandrin and gomisin A. In the present study, we prepared ethanol extracts of pomace of Schisandra chinensis (PSC) and investigated their effects on cell viability and expression changes of pro-apoptotic genes such as ATF3, NAG-1 and p21 in human colorectal cancer HCT116 cells. PSC significantly reduced cell viability in a dose-dependent manner, and also dramatically induced the expression of ATF3, NAG-1 and p21 genes, with resveratrol used as a positive control. We also assessed the effects of pure compound schizandrin (SZ) derived from Schisandra chinensis on cell viability and expression of pro-apoptotic genes such as ATF3, NAG-1 and p21. The results showed that SZ also decreased cell viabilities in a dose-dependent manner and increased the expression of ATF3, NAG-1 and p21 genes. In addition, apoptosis was detected in SZ-treated HCT116 cells, which was confirmed with PARP cleavage. PARP cleavage was recovered in part by the transfection of NAG-1 siRNA. The results indicate that NAG-1 is one of the genes responsible for apoptosis induced by SZ. Overall, our findings may contribute to understanding the molecular mechanisms of anti-proliferative and pro-apoptotic activities mediated by PSC and SZ.

• Korea lubricating oil industries association bulletin
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• no.60
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• pp.3-12
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• 1993

• Defense and Technology
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• no.9 s.103
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• pp.44-56
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• 1987

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.2
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• pp.591-595
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• 2016

The liver is one of the most common sites of cancer in the world, hepatocellular carcinoma (HCC) predominating. Chronic hepatitis B virus infection (CHB) is considered as an important potential risk factors for HCC. Different people have diverse responses to HBV infection regarding the likelihood of HCC development, and host factors such as single nucleotide polymorphisms (SNPs) might account for this. The present study was conducted to evaluate any association between SNP frequencies in two genes, XRCC4 (rs1805377) and ATF6 (rs2070150), and the risk of CHB and HCC development in Thai patients. The study covered 369 subjects including 121 HCC patients, 141 with chronic hepatitis B virus infection (CHB) and 107 healthy controls. With TaqMan real-time PCR, the results showed that no significant association between XRCC4 (rs1805377) and ATF6 (rs2070150) and risk of HCC in the Thai population. From this first study of the 2 polymorphisms and HCC in Thailand it can concluded that rs1805377 and rs2070150 polymorphisms may not be applicable as genetic markers in the Thai population for HCC assessment.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.97-97
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• 2018

Honey used as conventional medicine has various pharmacological properties. In the honey and anti-inflammatory effect, Gelam honey and Manuka honey has been reported to exert anti-inflammatory activity. However, the anti-inflammatory effect and potential mechanisms of acacia honey (AH) are not well understood. In this study, we investigated anti-inflammatory activity and mechanism of action of AH in LPS-stimulated RAW264.7 cells. AH attenuated NO production through inhibition of iNOS expression in LPS-stimulated RAW264.7 cells. AH also decreased the expressions of $IL-1{\beta}$, IL-6 and $TNF-{\alpha}$ as pro-inflammatory cytokines, and MCP-1 expression as a pro-inflammatory chemokine. In the elucidation of the molecular mechanisms, AH decreased LPS-mediated $I{\kappa}B-{\alpha}$ degradation and subsequent nuclear accumulation of p65, which resulted in the inhibition of $NF-{\kappa}B$ activation in RAW264.7 cells. AH dose-dependently suppressed LPS-mediated phosphorylation of ERK1/2 and p38 in RAW264.7 cells. In addition, AH significantly inhibited ATF2 phosphorylation and nuclear accumulation of ATF2 in LPS-stimulated RAW264.7 cells. These results suggest that AH has an anti-inflammatory effect, inhibiting the production of pro-inflammatory mediators such as NO, iNOS, $TNF-{\alpha}$, IL-6, $IL-1{\beta}$ and MCP-1 via interruption of the $NF-{\kappa}B$ and MAPK/ATF2 signaling pathways.

• Tribology and Lubricants
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• v.33 no.6
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• pp.269-274
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• 2017

Currently, fuel efficiency becomes one of critical issues for automotive industries as concerns about environmental and energy problems grow. In an automatic transmission of an automobile, a drag torque due to a viscous drag of a fluid between friction and clutch plates is one of factors that degrade fuel economy. In this work, the drag torque characteristics of a wet clutch was experimentally investigated with respect to rotational speed, temperature of automatic transmission fluid (ATF), and gap between friction and clutch plates. The experimental results showed that drag torque increases to a certain level, and then decrease to the steady state value with increasing rotational speed. This behavior may be associated with two-phase flow of air and ATF at gap between friction and clutch plates. Also, it was found that the maximum drag torque value decreased as ATF viscosity decreases with increasing temperature. However, it was shown that the point at which the maximum drag torque occurs was not significantly affected by the ATF temperature. In addition, maximum drag torque was found to decrease as the gap between friction and clutch plates increased from 0.1 mm to 0.2 mm. Furthermore, it was observed that the generation of maximum drag torque was delayed as the gap increased. The outcomes of this work are expected to be helpful to gain a better understanding of drag torque characteristic of a wet clutch, and may therefore be useful in the design of wet clutch systems with improved performance.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.44 no.3
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• pp.58-63
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• 2007

GPS signal is vulnerable to intentional and unintentional interferences since it has a very weak signal power and its structure is well-known. Among the interference rejecting techniques, the ATF is being generally used as a pre-correlation technique. However, it does not have a design parameter relating to the notch width, resulting in the spectral loss around frequency of the interference. The IIR notch filter has a design parameter relating to the notch width and can generate a sharp notch for the CW interference. In this paper, an adaptive IIR notch filter is proposed and the performance is evaluated using software signal generator and real measurements.

• Nuclear Engineering and Technology
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• v.48 no.1
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• pp.16-25
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• 2016

In severe loss of coolant accidents (LOCA), similar to those experienced at Fukushima Daiichi and Three Mile Island Unit 1, the zirconiumalloy fuel claddingmaterials are rapidlyheateddue to nuclear decay heating and rapid exothermic oxidation of zirconium with steam. This heating causes the cladding to rapidly react with steam, lose strength, burst or collapse, and generate large quantities of hydrogen gas. Although maintaining core cooling remains the highest priority in accident management, an accident tolerant fuel (ATF) design may extend coping and recovery time for operators to restore emergency power, and cooling, and achieve safe shutdown. An ATF is required to possess high resistance to steam oxidation to reduce hydrogen generation and sufficient mechanical strength to maintain fuel rod integrity and core coolability. The initiative undertaken by Electric Power Research Institute (EPRI) is to demonstrate the feasibility of developing an ATF cladding with capability to maintain its integrity in $1,200-1,500^{\circ}C$ steam for at least 24 hours. This ATF cladding utilizes thin-walled Mo-alloys coated with oxidation-resistant surface layers. The basic design consists of a thin-walled Mo alloy structural tube with a metallurgically bonded, oxidation-resistant outer layer. Two options are being investigated: a commercially available iron, chromium, and aluminum alloy with excellent high temperature oxidation resistance, and a Zr alloy with demonstratedcorrosionresistance.Asthese composite claddings will incorporate either no Zr, or thin Zr outer layers, hydrogen generation under severe LOCA conditions will be greatly reduced. Key technical challenges and uncertainties specific to Moalloy fuel cladding include: economic core design, industrial scale fabricability, radiation embrittlement, and corrosion and oxidation resistance during normal operation, transients, and severe accidents. Progress in each aspect has been made and key results are discussed in this document. In addition to assisting plants in meeting Light Water Reactor (LWR) challenges, accident-tolerant Mo-based cladding technologies are expected to be applicable for use in high-temperature helium and molten salt reactor designs, as well as nonnuclear high temperature applications.