• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 추계학술대회 논문집 전기물성,응용부문
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• pp.140-145
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• 2001

In order to apply for silane crosslinking process to PTC products, especially. self-regulating heater, silane crosslinked samples were compared with radiation crosslinked sample in terms of PTC characteristic and PTC stability. Silane crosslinked samples have lower PTC intensity than radiation crosslinked sample. It can be explained that multiple networks of silane crosslink restrict the movement of molecules in the composite as the sample is heating. As a result of heat cycles at $140^{\circ}C$, the changes of volume resistivity and PTC intensity for radiation crosslinked sample were higher than those of silane crosslinked samples. Whereas, in the case of heat cycles at $85^{\circ}C$, which is limiting temperature for self-regulating heater, both silane and radiation crosslinked samples show stable results without pronounce changes of resistivity up to five cycles.

• 한국자동차공학회논문집
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• 제9권5호
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• pp.179-187
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• 2001

In this paper, a primary pressure regulating type ratio control system is developed for a metal belt CVT, and the CVT ratio changing characteristics are investigated by simulation and experiment. The hydraulic part of the ratio control system has a simple structure with one 3-way spool valve as a main ratio control valve and one bleed type variable force solenoid as a pilot valve. The mathematical modelling of the CVT hydraulic system is derived by considering the CVT shift dynamics. Simulation results of CVT speed ratio and the primary pressure agree with the experimental results demonstrating the validity of the dynamic models. It is found from the simulation and experimental results that the response time of speed ratio and primary pressure can be shortened by increasing the ratio control valve port area, and the size of feedback orifice of ratio control valve gives a damping effect on the primary pressure oscillation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1716-1717
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• 2007

In this paper, a second order fuzzy sliding mode control that combines with a adaptive self-regulating technique is proposed for a nonlinear system with unknown dynamics. The chattering effect that is a representative disadvantage of the sliding mode control is avoided by using the second order sliding mode control instead of the first order sliding mode control. The proposed sub-controller is composed of the equivalent control that is approximated by an online rule regulation sheme and the hitting control that is used to constrain the states of the sub-system to maintain on the sub-sliding surface and used to guarantee the system robustness. Simulation results are presented to show the effectiveness of the proposed controller

• 한국식품과학회지
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• 제51권6호
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• pp.558-564
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• 2019

Hypertriglyceridemia is one of the metabolic syndrome that is often observed as a result of lipid abnormalities. It is associated with other lipids, metabolic disorders, cardiovascular disease and liver disease. Korean red ginseng is known to affect obesity, dyslipidemia, liver disease and liver function, but the mechanism of its effect is not clear. This study examined the beneficial effects of hypertriglyceridemia and the mechanism of action of Jinan red ginseng extract (JRG) in hepatoma cells. To measure the levels of triglyceride accumulation, we studied the expression of proteins and mRNAs related to lipidogenesis in hepatoma cells (Huh7 and HepG2). JRG decreases the lipidogenic markers, peroxisome proliferator-activated receptor γ (PPARγ), CCAAT-enhancer-binding proteins α (C/EBPα) and C/EBPβ which are major regulators of triglyceride synthesis in hepatoma cells. We also found that JRG reduced sterol regulatory element binding proteins 1c (SREBP-1c), C/EBPα and C/EBPβ by regulating liver X receptor (LXR) and stearoyl CoA desaturase (SCD) expressions. In addition, the first-limited step of synthesis triglyceride (TG), glycerol-3-phosphate (G3P) is decreased by JRG. These results suggest that the anti-hypertriglyceride effect of JRG in hepatoma cells could be accompanied with the inhibition of lipidogenic transcription factors by regulating LXR and SCD expression.

• 동의생리병리학회지
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• 제27권2호
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• pp.202-211
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• 2013

The purpose of this study is to investigate the apoptotic effect of Phellodendri Cortex water extract (PCWE) on pancreatic cancer cells and to find out the regulating mechanisms. Human-derived pancreatic cancer cell line, MIA PaCa-2 cells were treated by PCWE with various concentrations and the cytotoxicity was determined by MTT assay. The activation of Annexin V, DNA fragmentation, cell cycle arrest and caspase activation were observed to investigate the role of PCWE in pancreatic cancer cells. Also, to find out the regulating mechanisms, we examined the ROS production. The treatment of PCWE induced the cell death in both concentration and time dependent manner. The treatment of PCWE also increased the expression of Annexin V, DNA fragmentation, cell cycle arrest, and cleavage of caspase, which means cell-death PCWE induced was apoptosis but not necrosis. The ROS production was increased by PCWE treatment and the blockade of ROS inhibited the PCWE-induced cell death. These results could suggest that PCWE induced apoptosis via ROS release in pancreatic cancer cell.

• Asian Pacific Journal of Cancer Prevention
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• 제13권7호
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• pp.3259-3264
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• 2012

Curcumin (CM) possesses anti-cancer activity against a variety of tumors. Matrix metalloproteinases (MMPs) play an important role in remodeling the extracellular matrix and their activities are regulated by tissue inhibitor of metalloproteinases (TIMPs) family. Control of MMP and TIMP activity are now of great significance. In this study, the effect of CM is investigated on metastatic MMPs and anti-metastatic TIMPs genes on MDA breast cancer cells cultured in a mixture of DMEM and Ham's F12 medium and treated with different concentrations of CM (10, 20 and $40{\mu}M$ for various lengths of time. Reverse transcription followed by quantitative real time PCR was used to detect the gene expression levels of MMPs and TIMPs in CM-treated versus untreated cases and the data were analyzed by one-way ANOVA. At high concentrations of curcumin, TIMP-1, -2, -3 and -4 genes were up-regulated after 48 hours of treatment, their over-expression being accompanied by down-regulation of MMP-2 and MMP-9 gene expression levels in a concentration- and time-dependent manner. These results suggest that curcumin plays a role in regulating cell metastasis by inhibiting MMP-2 and MMP-9 and up-regulating TIMP1 and TIMP4 gene expression in breast cancer cells.

• 한국식품영양학회지
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• 제21권2호
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• pp.204-209
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• 2008

The present study examined the ex vivo effect of Job's tear on immune function. Seven to eight week old mice(Balb/c) were fed a chow diet ad libitum two different concentrations (50 and 500 mg/kg BW) of water extract of Job's tear were orally administ every other day for two weeks. The results indicated that macrophage activation had occurred in the mice receiving 50 mg/kg B. W. of Job's tear water extract. Overall, using a mouse model, this study demonstrated that Job's tear extract may enhance immune function by regulating the $IL-1{\beta}$, IL-6, $TNF-{\alpha}$ and IL-10 cytokine production capacity of activated macrophages in mice. This study may suggest that supplementation of Job's tear water extracts may enhance the immune function by regulating the enhancing the cytokine production by activated macrophage ex vivo.

• 혜화의학회지
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• 제9권2호
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• pp.197-209
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• 2001

In the Literal Study on the Effect of Acupuncture and Moxibustion Treatment on the Bungru, the results were as follows. 1. The Bungru means an abnormal bleeding of femail genetalia. and is devided to Bungjung and Bungha. 2. The etiological factors of Bungru are heat of blood, asthenic coldness. asthenia of chong and ren channels. deficiency of blood, deficiency of vital energy, stagnated blood. and asthenia of spleen & stomach. 3. In the frequency of practical use in Acupuncture treatment, the order was Ren channel, Bladder meridian. Liver meridian, Spleen meridian and Kidney meridian. 4. In the frequency of practical use in Moxibustion treatment, the order was Extra Points, Ren channel, Bladder meridian, Spleen meridian, Liver meridian and Kidney meridian. 5. The most using points of Acupuncture and Moxibustion Treatment on the Bungru were Samumgyo(Sp6), Taechung(Liv3), Hyoihae(Sp10), Umgok(B10), Kihae(CV6), Chung-guk(CV3), Kwanwon(CV4), Unbaek(Spl) and etc. 6. The charicteristics of the most used points were nourishing the spleen, regulating the middle warmer, cleaning the blood, promoting blood circulation, activating blood circulation, promoting the vital energy, regulating the obstruction of vital energy, nourishing the kidney and so on. 7. In the new Acupuncture therapy, Ear-acupuncture, Head-acupuncture, Foot-acupuncture and Skin-acupuncture were used.

• Biomolecules & Therapeutics
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• 제31권3호
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• pp.306-311
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• 2023

The current study aimed to reveal the potential effect of meclofenamate, a nonsteroidal anti-inflammatory drug, on the gene expression of airway MUC5AC mucin. Human pulmonary mucoepidermoid NCI-H292 cells were pretreated with meclofenamate for 30 min and stimulated with phorbol 12-myristate 13-acetate (PMA) for 24 h. Thereafter, the effect of meclofenamate on the PMA-induced nuclear factor kappa B (NF-kB) signaling pathway was assessed. Meclofenamate inhibited glycoprotein production and mRNA expression of MUC5AC mucins induced by PMA by inhibiting the degradation of inhibitory kappa Bα (IkBα) and NF-kB p65 nuclear translocation. These results suggest meclofenamate suppresses mucin gene expression by regulating NF-kB signaling pathway in human pulmonary epithelial cells.

• Journal of Microbiology and Biotechnology
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• 제28권1호
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• pp.40-49
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• 2018

We evaluated the antioxidant activity and neuronal cell-protective effect of fucoidan extract from Ecklonia cava (FEC) on hydrogen peroxide ($H_2O_2$)-induced cytotoxicity in PC-12 and MC-IXC cells to assess its protective effect against oxidative stress. Antioxidant activities were examined using the ABTS radical scavenging activity and malondialdehyde-inhibitory effect, and the results showed that FEC had significant antioxidant activity. Intracellular ROS contents and neuronal cell viability were investigated using the DCF-DA assay and MTT reduction assay. FEC also showed remarkable neuronal cell-protective effect compared with vitamin C as a positive control for both $H_2O_2$-treated PC-12 and MC-IXC cells. Based on the neuronal cell-protective effects, mitochondrial function was analyzed in PC-12 cells, and FEC significantly restored mitochondrial damage by increasing the mitochondrial membrane potential (${\Delta}{\Psi}m$) and ATP levels and regulating mitochondrial-mediated proteins (p-AMPK and BAX). Finally, the inhibitory effects against acetylcholinesterase (AChE), which is a critical hydrolyzing enzyme of the neurotransmitter acetylcholine in the cholinergic system, were investigated ($IC_{50}$ value = 1.3 mg/ml) and showed a mixed (competitive and noncompetitive) pattern of inhibition. Our findings suggest that FEC may be used as a potential material for alleviating oxidative stress-induced neuronal damage by regulating mitochondrial function and AChE inhibition.