• 생약학회지
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• 제49권3호
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• pp.231-239
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• 2018

Parkinson's disease (PD), one of common neurodegenerative diseases, is caused by the death of dopaminergic neurons in the substantia nigra pars compacta. The loss of dopaminergic neurons in PD is associated with oxidative stress and mitochondrial dysfunction. Hyperoside (quercetin 3-O-${\beta}$-D-galactopyranoside) was reported to have protective properties against oxidative stress by reducing intracellular reactive oxygen species (ROS) and increasing antioxidant enzyme activity. In this study, we examined the neuroprotective effect of hyperoside against 1-methyl-4-phenyl pyridinium ($MPP^+$)-induced cell model of PD and the underlying molecular mechanisms. Hyperoside significantly decreased $MPP^+$-induced cell death, accompanied by a reduction in poly ADP-ribose polymerase (PARP) cleavage. Furthermore, it attenuated $MPP^+$-induced intracellular ROS and disruption of mitochondrial membrane potential (MMP), with the reduction of Bax/Bcl-2 ratio. Moreover, hyperoside significantly increased the phosphorylation of Akt, but it has no effects on $GSK3{\beta}$ and MAPKs. Pharmacological inhibitor of PI3K/Akt abolished the cytoprotective effects of hyperoside against $MPP^+$. Taken together, these results demonstrate that hyperoside significantly attenuates $MPP^+$-induced neurotoxicity through PI3K/Akt signaling pathways in SH-SY5Y cells. Our findings suggest that hyperoside might be one of the potential candidates for the treatment of PD.

• 약학회지
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• 제30권6호
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• pp.352-355
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• 1986

Methyl-6-deoxy-$\beta$-L-idopyranoside was prepared in good yield by treatment of methyl 2,3,4-tri-O-benzyl-6-deoxy-$\alpha$-D-xylo-hex-5-enopyranoside with H$_2$ on pd, followed by reaction of Na/NH$_3$ at $-50^{\circ}C$. The ratio of L-idopyranoside and D-glucopyranoside was 7 to 1 in 80.7%. It was confirmed that L-idopyranoside was 1C conformation as being expected.

• Transactions on Electrical and Electronic Materials
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• 제7권6호
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• pp.313-318
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• 2006

This paper introduces a partial discharge (PD) severity metric, S, based on the evaluation of time-sequence PD data capture and resulting Time-Sequence-Analysis Discharge (TSAD) level distributions. Basically based on an IEC60270 measurement technique, each PD event is time stamped and the discharge level noted. By evaluating the time differences between a previous and subsequent discharge, a 3D plot of time-sequence activity and discharge levels can be produced. From these parameters a measurement of severity, which takes into account dynamic or instantaneous variations in both the time of occurrence and the level of discharge, rather than using standard repetition rate techniques, can be formulated. The idea is to provide a measure of the severity of PD activity for potentially measuring the state of insulation within an item of plant. This severity measure is evaluated for a simple point-plane geometry in $SF_{6}$ as a function of gap distance and applied high voltage. The results show that as the partial discharge activity increases, the severity measure also increases. The importance of future investigations, quantifications and evaluations of the robustness, sensitivity and importance of such a severity measurement, as well as comparing it with typical repetition rate assessment techniques, and other monitoring techniques, are also very briefly discussed.

• Korean Chemical Engineering Research
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• 제45권4호
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• pp.351-355
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• 2007

$C_4$ 잔사유에 포함되어 있는 2-부텐을 부가가치가 더 높은 1-부텐으로 위치 이성화하는 공정의 개발이 필요하다. 본 연구에서는 2-부텐을 1-부텐으로 전환하기 위하여 상업용 Pd/alumina 촉매를 사용하여 수첨이성화반응 실험을 수행하였다. 상업용 Pd 촉매인 LD-265 촉매가 같은 반응조건에서 다른 상업용 촉매들보다 1-부텐 수율이 높았다. 1-부텐의 최적반응조건은 반응온도 $75^{\circ}C$, 반응압력 150 psig, 2-부텐의 유량 48 cc/h, $H_2$ 유량 48 cc/h이었으며, 이 조건하에서 1-부텐의 수율이 5.3%로 최대임을 알 수 있었다. 수첨이성화 반응기와 증류탑으로 구성된 공정의 모사를 수행하였다. 순도 99.0% 이상의 1-부텐을 얻기 위해서 단 효율이 78% 일 때 환류비가 120이고 171 단의 증류탑이 필요한 것으로 나타났다.

• 한국전기전자재료학회논문지
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• 제31권3호
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• pp.160-164
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• 2018

We have proposed a hydrogen detection sensor based on a Pd (palladium)-coated, single-mode, optical fiber. The experimental results demonstrated that the sensor could detect hydrogen in air as well as in insulation oil. The influence of Pd film thickness and environmental temperature on response time and sensitivity was analyzed. The reflected optical power at the optical-fiber/Pd interface decreased as the concentration of hydrogen increased, in both air and the insulation oil. The sensor showed 0.75 dB of optical power variation when the concentration of dissolved hydrogen was saturated in the insulation oil.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
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• pp.506-509
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• 2003

In this paper, the $\Phi$-q-n pattern and average discharge power of silicone rubber have investigated effect of inter impurities. It's changed impurities by silicone oil, water and copper. Applied voltage is AC 3, 4, 4.5, 5, 5.5[kV]. And data acquisition time is 10 second(600 cycles). These results suggest that partial discharge(PD) is shower negative polar than positive polar at 3[kV]. Positive polar's PD value increased with increase of applied voltage. The Conductivities expressed same $\Phi$-q-n pattern in positive polar and negative polar at phase region.

• 한국안광학회지
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• 제20권1호
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• pp.61-66
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• 2015

목적: 본 연구에서는 하워드-돌먼 입체검사(Howard-Dolman test, HDTEST, Bernell, U.S.A)를 이용하여 20대 성인의 동적 입체시를 측정하여 남녀 간의 동적 입체시를 비교하고, 동공 간거리(PD; pupillary distance)와 좌우안의 구면굴절력의 차이로 인한 굴절부등과 동적 입체시의 상관관계를 분석해 보고자 하였다. 방법: 평균연령이 $22.68{\pm}0.50$(20~29)세인 20대 성인 63명(남자 30명, 여자 33명)을 대상으로 실험을 실시하였다. 굴절이상자는 완전교정을 한 후에 Howard-Dolman test(H-D Test)를 이용하여 2.5 m 검사거리에서 동적 입체시를 각각 5회 측정하였다. 결과: 전체 대상자의 동적 입체시의 평균은 $28.44{\pm}25.03$초였고, 이들 중 남자는 $28.23{\pm}23.34$초, 여자는 $28.63{\pm}26.83$초였다. PD 범위를 기준으로 한 동적 입체시에 있어서 PD가 59.80 mm이하 범위에서는 $33.87{\pm}18.53$초, 59.81~66.15 mm의 범위에서는 $26.24{\pm}25.26$초, 66.15 mm를 초과하는 범위에서는 $34.60{\pm}25.65$초로 나타났고, 유의한 차이는 보이지 않았다(P=0.73, r=0.03). 굴절부등의 차이를 기준으로 할 때 동적 입체시는 굴절부등이 1 D미만인 경우 $26.81{\pm}24.86$초, 1 D이상인 경우는 $1.45{\pm}24.18$초였고 유의한 차이는 없었다(P=0.15, r=0.15). 결론: H-D test를 이용해 20대 성인의 동적 입체시를 평가해 보았을 때, 남녀 간에 큰 차이가 없고, PD와 굴절부등은 동적 입체시에 큰 영향을 주지 않는 것으로 나타났다.

• 대한방사선치료학회지
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• 제20권1호
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• pp.11-15
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• 2008

목 적: 방사선치료계획에 있어서 정상조직과 치료부위의 선량 분포는 매우 중요하다. 이에 본원에서는 유방암 환자를 대상으로 Three-dimensional conformal radiation therapy (3D-CRT), Helical tomotherapy (TOMO)의 방법으로 방사선치료계획을 세웠으며 이에 선량분포를 분석하여 실제 임상에서의 적용여부를 알아보고자 한다. 대상 및 방법: 20명의(좌측: 10명, 우측: 10명) 유방보존절제술 환자를 대상으로 시행하였으며 방법으로는 같은 조건에서 3D-CRT는 Philips사의 Pinnacle을, TOMO는 TomoTherapy사의 TOMO Planning System을 이용해 치료계획을 세웠다. Dose-Volume Histogram (DVH)의 prescribed dose (PD)에 대한 PTV의 Homogeneity index (HI)와 Conformity index (CI)를 구하였고, 정상조직의 dose- volume 관계를 비교하였다. 결 과: Homogeneity index (HI)와 Conformity, index (CI)는 TOMO에서 우수한 결과를 나타났다. $V_{-50-IB-NPTV}$ (the percentage ipsilateral non-PTV breast volume that was delivered 50% of the prescribed dose)는 3D-CRT: 40.4%, TOMO: 18.3%, $V_{20-IL}$ (the average ipsilateral lung volume percentage receiving 20% of the prescribed dose)는 3D-CRT: 4.8%, TOMO: 14.2%, $V_{20-10H}$ (the average heart volume percentage delivered 20% and 10% of the prescribed dose in left breast cancer)는 3D-CRT: 1.6%, 3% TOMO: 9.7%, 26.3%의 결과를 보여준다. 결 론: 유방암 환자의 방사선치료계획 방법들은 PTV에서 원하는 선량분포를 보여줬다. 그러나 TOMO는 좋은 Homogeneity index (HI), Conformity index (CI)와 Breast를 보호하는 장점이 있는 반면에 Lung과 Heart에서는 많은 피폭선량이 있음을 알 수 있기에 TOMO의 방사선치료계획시 주의해야 할 점으로 사료된다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
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• pp.2265-2267
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• 2005

We present detailed studies of externally applicable UHF PD sensors for a metal covered epoxy barrier with a small opening of epoxy injection-hole. The sensors were attached at the surface of injection hole of a metal covered epoxy barrier. 3-Dimensional electro magnetic simulations were performed to analyze electric-field distribution of the GIS and epoxy barrier with injection hole. Sensor structures were designed and analyzed using the 3-D EM simulator then fabricated for experimental verification. Sensor performance was measured in terms of spectral response and detected peak power. Real scale GIS and epoxy barriers were used to test and measure various aspect of performance of the sensors.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 Techno-Fair 및 추계학술대회 논문집 전기물성,응용부문
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• pp.163-164
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• 2007

In this study, we developed intelligent spacer built in the internal type UHF PD sensors. 3-Dimensional electro-magnetic simulations were performed to analyze electric-field distribution of the single-phase GIS and three-phase GIS. After considering the spacer's specification, Sensor structures were designed and analyzed using the 3-D EM Simulator. As a result of the simulation the internal type UHF PD sensors were built in. Performance of the sensor built into real scale GIS spacer was measured in terms of return loss and detected Max voltage. And we identified a character of the intelligent spacer by using 5pC partial discharge ceil.