• 제목/요약/키워드: EPI

검색결과 544건 처리시간 0.032초

Reperfusion Hyperemia Demonstrated on Perfusion MRI: It′s Relationship with Programmed Cell Death

  • 이승구;김동익;김상흠;김시연;인연권
    • 대한자기공명의과학회:학술대회논문집
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    • 대한자기공명의과학회 2001년도 제6차 학술대회 초록집
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    • pp.170-170
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    • 2001
  • Purpose: To evaluate the relationship between reperfusion hyperemia in reversible cerebral ischem and the degree of programmed cell death. Method: We produced the animal models of reversible cerebral ischemia in 10 cats by mean of middle cerebral artery (MCA) occlusion with transorbital approach. MCA was occluded b microvascular clamp for an hour. MR imaging was performed at 0, 1, 2 days after ischemi and reperfusion. Perfusion (PWI) [Contrast enhanced GRE EPI, TR/TE= 1500/40, 40 Phases, 128 matrix, 12 cm FOV] and diffusion (DWI) (SE EPI, b=0, 500, 1000) weighted images were obtained using Philips Intera 1.57 system. rCBV and ADC maps were calculated wi IDL based postprocessing program. Tissue slices were obtained after the last MR imagin TUNEL, Calbin and Acid-Fuscin staining were done for corresponding slices as MR imagin We investigated the differences of degree of apoptosis in the area of reperfusion hyperemia.

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Antitumor activity of Trichosanthes kirilowii

  • Ryu, Shi-Yong;Lee, Seung-Ho;Lee, Sang-Un;Lee, Chong-Ock;No, Zaesung;Ahn, Jong-Woong
    • Archives of Pharmacal Research
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    • 제17권5호
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    • pp.348-353
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    • 1994
  • The activity fractionation upon the MeOH extract of the root of trichosanthes kirilowii led to the isolation of eight cucurbitane tritepense namely cucurbitacin .betha. (I), isocucurbitacin .betha.(II), cucurbitacin D(III), isocucurbitacin D(IV), 3-epi-isocucurbitacin .betha(V), dihydrocucurbitain .betha. (VI), dihydroisocucurgbitachin .betha. (VII) and dihydrocucurbitacin E (VIII), as active principles. All isolates were shown to exhibit significant cytotoxicity against cultured human tumor cells, including A-549, Sk-OV-3, Sk-MEL-2, XF-498 and HCT 15, with an exceptionally high potency.

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제어 반전 소자의 제조 및 그 특성 (Fabrication and Characteristics of the Controlled Inversion Devices)

  • 김진섭;이우일
    • 대한전자공학회논문지
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    • 제20권1호
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    • pp.45-49
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    • 1983
  • Metal/insulator/n epi-layer/p+구조의 CID(controlled inversion device)를 제조하였다. I-V 특성 곡선에서 ON상태와 OFF상태사이에 부성저항(negative resistance)영역이 나타났다. CID를 제조하기 위해서 행한 산화층 형성 과정에서 600℃에서 5분간 산화시킨 소자의 스위칭 및 홀딩 전압은 각각 5.0V와 2.5V였다. 그리고 입사된 광에 의해서 스위칭 전압은 감소하였으나 홀딩 전압은 변하지 않았다.

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뇌기능 자기공명 영상장치를 이용한 인간 미각에 대한 기초 연구

  • 김수현;이영우;최기승;조지연;박청수;이현용;신운재;은충기;권오식
    • 대한자기공명의과학회:학술대회논문집
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    • 대한자기공명의과학회 2003년도 제8차 학술대회 초록집
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    • pp.26-26
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    • 2003
  • 목적: 본 연구의 목적은 미각자극에 대한 인간 뇌의 활성화 영역을 측정하고 가시화하여 미각의 뇌 활성화 부위에 대한 기초자료를 마련하는데 있다. 대상 및 방법: 5명의 남자 대학생 (평균 24.8세)을 뇌기능 연구의 실험 대상자로 선정하였고, 대상자들은 미각에 이상이 없고 구강수술 경험이 없는 오른손잡이를 대상으로 3번에 걸쳐 EPI 혈액산 소농도의존(blood oxygen level dependent)법을 이용하여 미각자극에 의한 기능적 자기공명영상 실험을 수행하였다. 미각 자극을 위하여 5%의 saline을 사용하였으며 자체적으로 제작한 Stimulator를 사용하여 자극하였다. 자극은 3회의 휴식기간과 2회의 자극기간에 걸쳐 시행하였으며, 각 자극기간은 30초씩 5초 간격으로 이스 당 42개의 영상을 획득했다. Post-processing은 SPM99 (Statistical Parametric Mapping 99, The Wellcome Department of Cognitive Neurology, Oxford 1999)의 correlation법을 사용하여 threshold 0.4∼0.7의 범위에서 통계처리 하였으며, 활성화 영상은 EPI영상과 같은 부위의 T1 강조영상에 overlapping시켰다. 이렇게 얻어진 fMRI 영상으로 활성 영역의 위치를 분석하였다.

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Epi층의 농도 및 두께 변화에 따른 Multi-RESURF SOI LDMOSFET의 특성분석 (Breakdown and On-state characteristics of the Multi-RESURF SOI LDMOSFET)

  • 김형우;김상철;서길수;김남균;김은동
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2002년도 하계학술대회 논문집 C
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    • pp.1578-1580
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    • 2002
  • The breakdown and on-state characteristics of the multi-RESURF SOI LDMOSFET is presented. P-/n-epi layer thickness and doping concentration is varied from $2{\mu}m{\sim}5{\mu}m$ and $1{\times}10^{15}/cm^3{\sim}9{\times}10^{15}/cm^3$ to obtain optimum breakdown voltage and on-resistance. The breakdown and on-state characteristics of the device is verified by two-dimensional process simulator ATHENA and device simulator ATLAS.

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Hg1-xCdxTe를 이용한 64x1 선형 적외선 감지 소자 제작 (Fabrication of 64x1 linear array infrared detector using Hg1-xCdxTe)

  • 김진상;서상희
    • 센서학회지
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    • 제18권2호
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    • pp.135-138
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    • 2009
  • $64{\times}1$ forcal plane infrared detector has been fabricated by using HgCdTe epi layer. HgCdTe was grown on GaAs substrate by using metal organic chemical vapor deposition. This paper describes key developments in the epi layer growth and device fabrication process. The performance of IR imaging system is summarized.

Epi-Leptosphaerin: A New L-Isoascorbic Acid Derivative from Marine Sponges

  • Kulkarni, Roshan R.;Jo, A Reum;Kim, Young Ho;Na, MinKyun
    • Natural Product Sciences
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    • 제21권4호
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    • pp.293-296
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    • 2015
  • A new L-isoascorbic acid derivative epi-leptosphaerin (1) and two known compounds leptosphaerin (2), and verongamine (3) were isolated from sponges of the orders Verongida and Thorectidae. Compounds 1 and 2 are most likely of sponge-associated fungal origin. In the present study, isolated compounds were investigated for their inhibition of soluble epoxide hydrolase (sEH), which is considered a promising target for the management of pain, inflammation, and comorbidities associated with diabetes. Compound 3, verongamine, displayed weak inhibitory activity against sEH with an $IC_{50}$ value $51.5{\pm}1.0{\mu}M$.

Epi poly를 이용한 MEMS 소자용 웨이퍼 단위의 진공 패키징에 대한 연구 (A Study on Wafer Level Vacuum Packaging using Epi poly for MEMS Applications)

  • 석선호;이병렬;전국진
    • 반도체디스플레이기술학회지
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    • 제1권1호
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    • pp.15-19
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    • 2002
  • A new vacuum packaging process in wafer level is developed for the surface micromachining devices using glass silicon anodic bonding technology. The inside pressure of the packaged device was measured indirectly by the quality factor of the mechanical resonator. The measured Q factor was about 5$\times10^4$ and the estimated inner pressure was about 1 mTorr. And it is also possible to change the inside pressure of the packaged devices from 2 Torr to 1 mTorr by varying the amount of the Ti gettering material. The long-term stability test is still on the way, but in initial characterization, the yield is about 80% and the vacuum degradation with time was not observed.

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식사시의 교감-부신계 활성도와 체온 및 신체계측치와의 관련성 (Relationships between BMI, Body Temperature and Syrnpathoadrenal Activity during a Meal)

  • 김석영;임상선;박필숙
    • Journal of Nutrition and Health
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    • 제31권7호
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    • pp.1130-1138
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    • 1998
  • The objective of this study was to investigate the relationship between changes in body temperature, adiposity and sympathoadrenal activity in normal weight female college students, eating an instant-noodle lunch in a laboratory setting at ambient temperatures of 22-24.8$^{\circ}C$. Preprandial epinephrine(EPI) concentration, as an indicator of adrenal activity, was inversely and significantly correlated with body weight, body mass index(BMI), and waist girth. Changes in pre- and postprandial EPI concentrations showed positive correlations with % body fat, fat mass, waist girth, hip girth, and waist/hip girth ratio(WHR). The preprandial norepinephrine (NE) concentration was negatively correlated with recovery time from the peak postprandial core temperature to the meal-start core temperature(RTST). However, the NE concentration, an indicator of sympathetic neural activity, was not related to anthropometric measurements in normal weight young women. In conclusion, adrenal activity was negatively associated with adiposity and central body fat distribution. Sympathetic activity was related to body temperature regulation capacity after a meal, but was not related to adiposity in normal weight young women. (Korean J Nutrition 31(7) 1130-1138, 1998)

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A Cipadesin Limonoid and a Tirucallane Triterpene from the Fruit of Sandoricum koetjape and their Inhibitory Properties against Receptor Tyrosine Kinases

  • Rachmadhaningtiyas, Dyah Ayu;Heliawati, Leny;Hermawati, Elvira;Syah, Yana Maolana
    • Natural Product Sciences
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    • 제27권2호
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    • pp.134-139
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    • 2021
  • A new cipadesin limonoid, i.e. 3-epi-cipadonoid C (1), and a new tirucallane triterpene, i.e. hispidol B 3-palmitate (3), have been isolated from the seeds and fruit peels extract of Sandoricum koetjape, respectively. Along with these compounds the known limonoid, cipaferen G (2), and two pentacyclic triterpenes, bryonolic (4) and bryononic (5) acids, were also isolated. The strucrures of the new compounds were elucidated by the analysis of NMR and mass spectral data. Compounds 1 - 5 were evaluated as the inhibitor of receptor tyrosine kinases (EGFR, Epidermal Growth Factor Receptor; HER2, HER4, Human Epidermal growth factor Receptor 2, -4; IGFR, Insulin-like Growth Factor Receptor; InsR, Insulin Receptor; KDR, Kinase insert Domain Receptor; PDGFRα, and PDGFRβ, Platelet-Derived Growth Factor Receptor-α and -β). The results showed only 1 and 3 that have weak activity against InsR.