• 생약학회지
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• 제35권3호통권138호
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• pp.244-249
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• 2004

The effects of hesperetin and naringenin on $NF-{\kappa}B$ activation were investigated in normal rat kidney cells transformed by temperature sensitive Rous Sarcoma Virus (tsNRK). The flavonoids, naringenin and hesperetin, significantly reduced v-Src-induced $NF-{\kappa}B$ activation as well as phosphorylation of Akt and GSK-3 in tsNRK cells, whereas these compounds did not effect on platelet-derived growth factor (PDGF)-induced $NF-{\kappa}B$ activation in $NIH3T3{\gamma}l$ cells. In addition, the DNA binding activity of SP-I was also reduced but that of AP-1 was not affected by the compounds. Our study suggests that Src-induced $NF-{\kappa}B$ activation could occur via Akt-GSK-3 pathway without $IkB{\alpha}$ degradation and that naringenin and hesperetin could be used in the treatment of cancer through the inhibition of $NF-{\kappa}B$ activation.

• 천문학논총
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• 제30권2호
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• pp.119-120
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• 2015

We report results of the measurement of the trigonometric parallax of an $H_2O$ maser source in IRAS 22555+6213 with the VLBI Exploration of Radio Astrometry (VERA). The annual parallax was determined to be $0.278{\pm}0.019$ mas, corresponding to a distance of $3.66^{+0.30}_{-0.26}kpc$. Our results confirm that IRAS 22555+6213 is located in the Perseus arm. We computed the peculiar motion of IRAS 22555+6213 to be ($U_{src}$, $V_{src}$, $W_{src}$) = ($0{\pm}1$, $-32{\pm}1$, $9{\pm}1$) $km\;s^{-1}$, where $U_{src}$, $V_{src}$, and $W_{src}$ are directed toward the Galactic center, in the direction of Galactic rotation and toward the Galactic north pole, respectively. IRAS 22555+6213, NGC7538 and Cepheus A lie along the same line of sight, and are within $2^{\circ}$ on the sky. Their parallax distances, with which we derived their absolute position in the Milky Way, show that IRAS 22555+6213 and NGC7538 are associated with the Perseus arm, while Cepheus A is located in the Local arm. We compared the kinematic distances of IRAS 22555+6213 derived with flat and non-flat rotation curve with its parallax distance and found the kinematic distance derived from the non-flat rotation assumption ($-32km\;s^{-1}$ lag) to be consistent with the parallax distance.

• 전력전자학회논문지
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• 제4권5호
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• pp.397-404
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• 1999

본 연구에서는 선형화 소신호 모델을 이용하여 불연속 모드 펄스폭 공진회로의 다양한 제어방법에 대하여 조사 하였다. 각 제어방식에 따른 시스템의 안정도와 동적 특성을 분석하기 위하여 정규화 출력 전류와 전압을 사용한 근궤적을 나타내었다. 또한, 최적의 궤적 특성을 가지는 제어기를 새로이 제안하였으며, 이러한 제어의 우수한 특성을 다른 형태의 제어방식과 비교함으로써 입증하였다.

• 전기학회논문지
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• 제61권3호
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• pp.394-400
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• 2012

In this paper, charging modes of series resonant converter for a high voltage energy storage capacitor are compared in terms of charging time, peak resonant current, normalized peak resonant current and voltage in each operation mode. Operating principles of the full bridge series resonant converter with capacitor load are explained and analyzed in discontinuous and continuous operation mode. Based on the analysis and simulation result, $0.6{\omega}_r$ < ${\omega}_s$ < $0.75{\omega}_r$ and $1.3{\omega}_r$ < ${\omega}_s$ < $1.4{\omega}_r$ are evaluated to the best range of switching frequency for charging of an high voltage energy storage capacitor. 1.8 kJ/s SRC prototype is assembled with TI 28335 DSP controller and 40 kJ, 7 kV energy storage capacitor. Design rules based on the comparative analysis are verified by experiment.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2020년도 전력전자학술대회
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• pp.255-256
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• 2020

본 논문은 0V에서 100V까지 매우 높은 승·강압비를 갖는 양방향 DC-DC 컨버터를 제안한다. 제안하는 시스템은 2-Stage 구조로 SRC(Series Resonant Converter)와 DBC(Differential Buck Converter)로 구성된다. 제안하는 컨버터의 출력 전압은 두 개의 각 벅 컨버터 출력 전압의 전위차로 결정되기 때문에 0V에서도 높은 전압으로 승압이 가능하다. 본 논문에서는 제안하는 컨버터의 타당성을 검증하기 위하여 15kW급 시작품을 제작하였고 96.27%의 최고효율을 달성하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2019년도 전력전자학술대회
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• pp.356-357
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• 2019

본 논문에서는 넓은 충전 전압 범위와 V2G 기능을 갖는 급속 충전기용 DC-DC 컨버터를 제안한다. 제안한 컨버터는 SRC(Series Resonant Converter)와 2상 Buck/Boost 컨버터로 구성된 2-stage 구조로써 넓은 충전 전압 범위에 적합하며, 배터리 충전뿐만 아닌 V2G(Vehicle to Grid) 동작이 가능하다. 또한 2상 인터리빙 방식을 사용함으로써 전류 분담을 통해 소자의 전류 정격 및 출력 필터 사이즈를 낮출 수 있다. 제안하는 컨버터의 시작품 실험을 통해 타당성을 검증하였다.

• 전력전자학회논문지
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• 제20권1호
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• pp.31-37
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• 2015

This paper proposes a 3.3-kW bi-directional EV charger with V2G and V2H functions. The bi-directional EV charger consists of a DC-DC converter and a DC-AC inverter. The proposed EV charger is suitable for wide battery voltage control due to the two-stage configuration of the DC-DC converter. By employing a fixed-frequency series loaded resonant converter as the isolated DC-DC converter, zero-current-switching can be achieved regardless of battery voltage variation, load variation, and power flow. A 3.3-kW prototype of the proposed EV charger has been built and verified with experiments, and indicates a maximum efficiency of 94.39% and rated efficiency of 94.23%.

• Genomics & Informatics
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• 제9권3호
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• pp.102-113
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• 2011

C-terminal SRC kinase (CSK) is a ubiquitously expressed, cytosolic enzyme that phosphorylates and inactivates several SRC family protein tyrosine kinases. Recent genomewide association studies have implicated CSK in the regulation of blood pressure. The current study aim is to determine the blood pressure association of the genes regulated by CSK down-regulation. The CSK mRNA expression was downregulated in vascular smooth muscle cells using small interfering RNA (siRNA). CSK mRNA levels fell by 90% in cells that were treated with CSK siRNA; the RNA from these cells was examined by microarray using the Illumina HumanRef-8 v3 platform, which comprises 24,526 reference mRNA probes. On treatment with CSK siRNA, 19 genes were downregulated by more than 2-fold and 13 genes were upregulated by more than 2-fold. Three (CANX, SLC30A7, and HMOX1) of them revealed more than 3 fold differential expression. Interestingly, the HMOX1 SNPs were associated with diastolic blood pressure in the 7551 Koreans using Korea Association REsource data, and the result was supported by the other reports that HMOX1 linked to blood vessel maintenance. Among the remaining 29 differentially expressed genes, seven (SSBP1, CDH2, YWHAE, ME2, PFTK1, G3BP2, and TUFT1) revealed association with both systolic and diastolic blood pressures. The CDH2 gene was linked to blood pressures. Conclusively, we identified 32 differentially expressed genes which were regulated by CSK reduction, and two (HOMX1 and CDH2) of them might influence the blood pressure regulation through CSK pathway.

• The Korean Journal of Physiology and Pharmacology
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• 제20권3호
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• pp.253-259
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• 2016

Previously, we found that KTH-13 isolated from the butanol fraction of Cordyceps bassiana (Cb-BF) displayed anti-cancer activity. To improve its antiproliferative activity and production yield, we employed a total synthetic approach and derivatized KTH-13 to obtain chemical analogs. In this study, one KTH-13 derivative, 4-(tert-butyl)-2,6-bis(1-phenylethyl)phenol (KTH-13-t-Bu), was selected to test its anti-cancer activity. KTH-13-t-Bu diminished the proliferation of C6 glioma, MDA-MB-231, LoVo, and HCT-15 cells. KTH-13-t-Bu induced morphological changes in C6 glioma cells in a dose-dependent manner. KTH-13-t-Bu also increased the level of early apoptotic cells stained with annexin V-FITC. Furthermore, KTH-13-t-Bu increased the levels of cleaved caspase-3 and -9. In contrast, KTH-13-t-Bu upregulated the levels of pro- and cleaved forms of caspase-3, -8, and -9 and Bcl- 2. Phospho-STAT3, phospho-Src, and phospho-AKT levels were also diminished by KTH13-t-Bu treatment. Therefore, these results strongly suggest that KTH-13-t-Bu can be considered a novel anti-cancer drug displaying pro-apoptotic activity.

• Biomolecules & Therapeutics
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• 제20권4호
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• pp.393-398
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• 2012

Recently, we reported that defective autophagy may contribute to the inhibition of the growth in response to PP2 (4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine), a selective SFK inhibitor, in multidrug-resistant v-Ha-ras-transformed NIH 3T3 cells (Ras-NIH 3T3/Mdr). In this study, we demonstrated that PP2 induces LC3 conversion via a mechanism that is uncoupled from autophagy and increases apoptosis in Ras-NIH 3T3/Mdr cells. PP2 preferentially induced autophagy in Ras-NIH 3T3 cells rather than in Ras-NIH 3T3/Mdr cells as determined by LC3-I to LC3-II conversion and GFP-LC3 fluorescence microscopy. Beclin 1 knockdown experiments showed that, regardless of drug resistance, PP2 induces autophagy via a Beclin 1-dependent mechanism. PP2 induced a conformational change in Beclin 1, resulting in the enhancement of the pro-autophagic activity of Beclin 1, in Ras-NIH 3T3 cells. Further, PI3K inhibition induced by wortmannin caused a significant increase in apoptosis in Ras-NIH 3T3 cells, as demonstrated by flow cytometric analysis of Annexin V staining, implying that autophagy inhibition through PI3K increases apoptosis in response to PP2 in Ras-NIH 3T3 cells. However, despite the fact that wortmannin abrogates PP2-induced GFP-LC3 punctae formation, some LC3 conversion remains in Ras-NIH 3T3/Mdr cells, suggesting that LC3 conversion may occur in an autophagy-independent manner. Taken together, these results suggest that PP2 induces LC3 conversion independent of PI3K, concomitant with the uncoupling of LC3 conversion from autophagy, in multidrug-resistant cells.