• 한국정밀공학회지
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• 제33권7호
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• pp.601-606
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• 2016

In this paper, an energy harvester is developed that has advantages regarding piezoelectric noise minimization, mass production, and an easily available environmental energy source, electromagnetic induction, as well as low-frequency bandwidth and high amplitude. A process for fabricating a three-dimensional multilayered planar coil using micro-electro-mechanical systems (MEMS) on a flexible printed circuit board FPCB is introduced. Optimal shape and size were calculated via internal resistance and inductance, and a prototype was fabricated through the MEMS procedure while considering the possibility of mass production. Although the internal resistance matched the designed value, the electromotive force generated did not reach the intended amount. The main reason for the decrease in efficiency was the low area of coil outskirt exposed to the magnetic field while there was relative motion between the magnet and the coil.

• Molecules and Cells
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• 제43권10호
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• pp.841-847
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• 2020

Histone acetylation and deacetylation play central roles in the regulation of chromatin structure and transcription by RNA polymerase II (RNA Pol II). Although Hda1 histone deacetylase complex (Hda1C) is known to selectively deacetylate histone H3 and H2B to repress transcription, previous studies have suggested its potential roles in histone H4 deacetylation. Recently, we have shown that Hda1C has two distinct functions in histone deacetylation and transcription. Histone H4-specific deacetylation at highly transcribed genes negatively regulates RNA Pol II elongation and H3 deacetylation at inactive genes fine-tunes the kinetics of gene induction upon environmental changes. Here, we review the recent understandings of transcriptional regulation via histone deacetylation by Hda1C. In addition, we discuss the potential mechanisms for histone substrate switching by Hda1C, depending on transcriptional frequency and activity.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 춘계학술대회
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• pp.51-54
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• 2005

Generator efficiency optimization is important for economic saving and environmental pollution reduction. In general, the machine loss can be reduced by the decreasing the flux level, resulting in the significant reduction of the core loss. This paper proposesan model-based controller is used to decrement the excitation current component on the basis of measured stator current and machine parameters and the q-axis current component controls the generator torque, by which the speed of the induction generator iscontrolled according to the variation of the wind speed in order to produce the maximum output power. The generator reference speed is adjusted according to the optimum tip-speed ratio. The generated power flows into the utility grid through the back-to-back PWM converter. The grid-side converter controls the dc link voltage and the line-side power factor by the q-axis and the d-axis current control, respectively. Experimental results are shown to verify the validity of the proposed scheme.

• 한국재료학회지
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• 제14권9호
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• pp.655-658
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• 2004

Lithium ferrites are a low-cost material which have been prominent in the high frequency core industry because of their excellent temperature performance and high squareness ratio. In order to develope the lithium ferrites with the high squareness and low coercive force, the ferrites of $Li_{0.48}Bi_{0.02}Ni_{0.04}Fe_{2.46-x}O_4$ were investigated the by varying composition, temperature and frequency. Electric loss of the Li-ferrite was lowered with the substitution of $Mn_{2}O_3$. The addition of $Mn_{2}O_3$ increased the magnetic induction (Bm&Br) but decreased the coercive force (Hc) and the squareness ratio (R=Br/Bm). Also, the Br value was stable at environmental temperature variation.

• Toxicological Research
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• 제27권3호
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• pp.167-172
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• 2011

We demonstrate that glycoprotein isolated from Dioscorea batatas (GDB) activates macrophage function. Analysis of the infiltration of macrophages into peritoneal cavity showed GDB treatment significantly increased the recruitment of macrophages into the peritoneal cavity. In order to further confirm and investigate the mechanism of GDB on macrophage activation, we analyzed the effects of GDB on the cytokine expression including IL-$1{\beta}$, TNF-${\alpha}$, and IL-6 in mouse peritoneal macrophages. GDB increased the expression of IL-$1{\beta}$, TNF-${\alpha}$, and IL-6. Cytokine induction by GDB was further confirmed by RT-PCR and ELISA in mouse macrophage cell line, RAW264.7 cells. Treatment of RAW264.7 cells with GDB produced strong induction of NF-${\kappa}B$ DNA binding and MAPK phosphorylation, markers for macrophage activation and important factors for cytokine gene expression. Collectively, this series of experiments indicates that GDB stimulates macrophage activation.

• Toxicological Research
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• 제25권4호
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• pp.195-201
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• 2009

Recent publications showed that metal nanoparticles which are made from $TiO_2,\;CeO_2,\;Al_2O_3,\;CuCl_2,\;AgNO_3$ and $ZnO_2$ induced oxidative stress and pro-inflammatory effects in cultured cells and the responses seemed to be common toxic pathway of metal nanoparticles to the ultimate toxicity in animals as well as cellular level. In this study, we compared the gene expression induced by two different types of metal oxide nanoparticles, titanium dioxide nanoparticles (TNP) and cerium dioxide nanoparticles (CNP) using microarray analysis. About 50 genes including interleukin 6, interleukin 1, platelet-derived growth factor $\beta$, and leukemia inhibitory factor were induced in cultured BEAS2B cells treated with TNP 40 ppm. When we compared the induction levels of genes in TNP-treated cells to those in CNP-treated cells, the induction levels were very correlated in various gene categories (r=0.645). This may suggest a possible common toxic mechanism of metal oxide nanoparticles.

• Toxicological Research
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• 제7권1호
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• pp.93-112
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• 1991

This study was carried out to investigate the various factors on induction of experimental hepatocarcinogenesis in Sprauge-Dawley rats. The experimental animals were divided into three Experiment. Experiment I, II and III were began rats with initial age of 6, 16 and 55 weeks, respectively. All Experiment were injected intrapertioneal with diethylnitrosamine (DENA` 200 mg/kg) as an intiator and group 3, 4 of Experiment I, II and III were fed on diet containing 0.02% 2-acetylaminofluorene (2-AFF) as a promoter for 6 weeks. Three weeks after two-thirds partial hepatectomy was performed in group 2, 4 of Experiment I & II and group 3 of Experiment III.

• Toxicological Research
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• 제11권2호
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• pp.235-239
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• 1995

This study was conducted to investigate the metallothionein (MT) induction by Panax ginseng C. A. Meyer in cadmium chloride intoxication. The results were as follows: Generally, detoxicatlon effects by Panax ginseng C. A. Meyer extract increased proportionally to the increase of cadmium concentrations. When a 8 mg/g dosage of cadmium was administered, formation of the cadmium and EDTA complex showed the highest antitoxic effect. Also, when a 4 mg/g dosage of cadmium was administered, Panax ginseng C. A. Meyer extract showed the highest antitoxic effect in metallothionein induction. According to the above results, Panax ginseng C. A. Meyer extract administered with cadmium increased metallothionein concentration and decreased the toxicity of cadmium in liver.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2002년도 Current Trends in Toxicological Sciences
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• pp.78-78
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• 2002

Microsomal epoxide hydrolase (mEH), an epoxide detoxifying enzyme and putative cell surface autoantigen, is inducible by xenobiotics and by certain pathophysiological conditions. The present study was designed to determine mEH expression in H4IIE cells during cell death initiated by sulfur amino acid deprivation (SAAD) and to identify the signaling pathway for the enzyme induction.(omitted)

• 한국독성학회:학술대회논문집
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• 한국독성학회 2002년도 Current Trends in Toxicological Sciences
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• pp.87-87
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• 2002

We have investigated the effects of genistein on induction of cyclooxygenase-2 (COX-2) that plays an important role in the pathophysiology of carcinogenesis as well as in cellular response to inflammatory stimuli. Treatment of MCF10A cells with 12-O-Tetradecanoylphorbol-13-acetate (TPA) or TNF-$\alpha$ resulted in increased COX-2 expression and PGE$_2$ production, which was inhibited by genistein.(omitted)