• Title/Summary/Keyword: CTA

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Radius Intermedius Stenosis Induced Myocardial Perfusion Defect: Provened by the Fusion Images of Myocardial Perfusion SPECT and 64 Channel CTA (심근관류 SPECT와 64채널 전산화 단층혈관 촬영 사진 융합으로 증명된 radius intermedius 협착에 의한 심근관류 저하)

  • Kong, Eun-Jung;Cho, Ihn-Ho;Chun, Kyung-Ah;Won, Kyu-Chang;Lee, Hyung-Woo;Park, Jong-Seon
    • Nuclear Medicine and Molecular Imaging
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    • v.42 no.1
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    • pp.77-78
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    • 2008
  • A 71-year-old woman was assigned to our department for Tc-99m myocardial perfusion SPECT(MPS) and coronary CT angiography. She admitted for substernal pain, via the ER, 2 days ago. The heart was scanned after intravenous injection of 925 MBq of $^{99m}Tc$-sestamibi adenosine-induced stress SPECT using dual head gamma camera (Hawkeye, GE healthcare. USA). The MPS shows decreased tracer uptake in the apical & mid area of anterior & lateral wall and mid & basal inferior wall. Coronary CT angiograph was obtained using Discovery VCT (GE healthcare). 3D angiography portrayed significant stenosis of ramus intermedius(RI) and posterolateral branch of right coronary artery(PLB) with fibrocalcified plaque. Two images were fused using Cardiac IQ fusion softwear package (Advantage workstation 4.4, GE healthcare) The fusion images explain the perfusion defect of anterior, lateral and inferior wall is due to stenosis of the RI and PLB. And 3 days later, coronary angiography was done and revealed the marked stenosis of RI and PLB. Then balloon angioplasty and stent was instituted in RI. Cardiac SPECT/CT fusion imaging provides additional information about hemodynamic relevance and facilitates lesion interpretation by allowing exact allocation of perfusion defects to its subtending coronary artery.

Influence of carrier suppressors on electrical properties of solution-derived InZnO-based thin-film transistors

  • Sim, Jae-Jun;Park, Sang-Hui;Jo, Won-Ju
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.262-262
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    • 2016
  • 최근 고해상도 디스플레이가 주목받으면서 기존 비정질 실리콘(a-Si)을 대체할 수 있는 재료에 관한 연구가 활발히 진행되고 있다. a-Si의 경우 간단한 공정 과정, 적은 생산비용, 대면적화가 가능하다는 장점이 있지만 전자 이동도가 매우 낮은 단점이 있다. 반면, 산화물 반도체는 비정질 상태에서 전자 이동도가 높으며 큰 밴드갭을 가지고 있어 투명한 특성을 나타낼 뿐만 아니라, 저온공정이 가능하여 기판의 제한이 없는 장점을 가지고 있다. 대표적으로 가장 널리 연구되고 있는 산화물 반도체는 a-IGZO(amorphous indium-gallium-zinc oxide)이다. 그러나 InZnO(IZO) 기반의 산화물 반도체에서 carrier suppressor 역할을 하는 Ga(gallium)은 수요에 대한 공급이 원활하지 못하여 비싸다는 단점이 있다. 그러므로 경제적이면서 a-IGZO와 유사한 전기적 특성을 나타낼 수 있는 suppressor 물질이 필요하다. 따라서 본 연구에서는 IZO 기반의 산화물 반도체에서 Ga을 Hf(hafnium), Zr(zirconium), Si(silicon)으로 대체하여 용액증착(solution-deposition) 공정으로 각각의 채널층을 형성한 back-gate type의 박막 트랜지스터(thin-film transistor, TFT) 소자를 제작하였다. 용액증착 공정은 물질의 비율을 자유롭게 조절할 수 있고, 대기압의 조건에서도 공정이 가능하기 때문에 짧은 공정시간과 저비용의 장점이 있다. 제작된 소자는 p-type Si 위에 게이트 절연막으로 100 nm의 열산화막이 성장된 기판을 사용하였다. 표준 RCA 클리닝 후에 각 solution 물질을 spin coating 방식으로 증착하였다. 이후, photolithography, develop, wet etching의 과정을 거쳐 채널층 패턴을 형성하였다. 또한, 산화물 반도체의 전기적 특성을 향상시키기 위해서 후속 열처리 과정(post deposition annealing, PDA)은 필수적이다. CTA 방식은 높은 열처리 온도와 긴 열처리 시간의 단점이 있다. 따라서, 본 연구에서는 $100^{\circ}C$ 이하의 낮은 온도와 짧은 열처리 시간의 장점을 가지는 MWI (microwave irradiation)를 후속 열처리로 진행하였다. 그 결과, 각 물질로 구현된 소자들은 기존 a-IGZO와 비교하여 적은 양의 carrier suppressor로도 우수한 전기적 특성 및 안정성을 얻을 수 있었다. 따라서, Si, Hf, Zr 기반의 산화물 반도체는 기존의 Ga을 대체하여 저비용으로 디스플레이를 구현할 수 있는 IZO 기반 재료로 기대된다.

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Buoyancy-Affected Separated Laminar Flow over a Vertically Located, Two-Dimensional Backward-Facing Step (수직으로 놓인 후향계단위를 흐르는 유체유동에 미치는 부력의 영향에 관한 연구)

  • 백병준;박복춘;김진택
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.5
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    • pp.1253-1261
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    • 1993
  • Numerical analysis and measurements of the velocity and temperature distributions in buoyancy assisting laminar mixed convection flow over a vertically located, two-dimensional backward-facing step are reported. Laser-Doppler Velocimeter and Constant Temperature Anemometer operated in constant current were used to measure simultaneously the velocity and temperature distributions in the recirculation region downstream of the step. The reattachment length was measured by using flow visualization technique for different inlet velocities, wall temperatures and step heights. While the reattachment length $X_r$ increases as the inlet velocity or step height increase, it decreases as the buoyancy force increases, causing the size of the recirculation region to decrease. For the experimental range of $Gr_s$/$Re_{s}^{2}$$\times$$10^3$<17, a correlation equation for the reattachment length can be given by $X_{r}=1.05(2.13+0.021 Re_{s})exp$ $(-33.7_s^{-0.186}/Gr_{s}/Re_{s}^2).$ The Nusselt number is found to increase and the location of its maximum value moves closer to the step as the buoyancy force increases. The location of the maximum Nusselt number occurs downstream of the reattachment point, and distance between the reattachment point and the location of the maximum Nusselt mumber increases as the buoyancy force increases. Computational prediction agrees favorably well with measured results.

Transcript accumulation of carotenoid biosynthesis genes in the cyanobacterium Synechocystis sp. PCC 6803 during the dark-to-light transition is mediated by photosynthetic electron transport

  • Ryu, Jee-Youn;Song, Ji-Young;Chung, Young-Ho;Park, Young-Mok;Chow, Wah-Soon;Park, Youn-Il
    • Plant Biotechnology Reports
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    • v.4 no.2
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    • pp.149-155
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    • 2010
  • Expression of the genes for carotenoid bio-synthesis (crt) is dependent on light, but little is known about the underlying mechanism of light sensing and signalling in the cyanobacterium Synechocystis sp. PCC 6803 (hereafter, Synechocystis). In the present study, we investigated the light-induced increase in the transcript levels of Synechocystis crt genes, including phytoene synthase (crtB), phytoene desaturase (crtP), ${\zeta}$-carotene desaturase (crtQ), and ${\beta}$-carotene hydroxylase (crtR), during a darkto-light transition period. During the dark-to-light shift, the increase in the crt transcript levels was not affected by mutations in cyanobacterial photoreceptors, such as phytochromes (cph1, cph2 and cph3) and a cryptochrome-type photoreceptor (ccry), or respiratory electron transport components NDH and Cyd/CtaI. However, treatment with photosynthetic electron transport inhibitors significantly diminished the accumulation of crt gene transcripts. Therefore, the light induction of the Synechocystis crt gene expression is most likely mediated by photosynthetic electron transport rather than by cyanobacterial photoreceptors during the dark-to-light transition.

Delayed Diagnosis of Cerebral Infarction after Complete Occlusion of ICA due to Blunt Head Trauma: A Case of Report (두부둔상 후 내경동맥손상으로 인한 뇌경색의 지연진단: 증례보고)

  • Yun, Jung-Ho;Ko, Jung Ho;Cho, Chun-Sung
    • Journal of Trauma and Injury
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    • v.28 no.3
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    • pp.190-194
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    • 2015
  • Blunt cerebrovascular injury is defined as a vertebral or carotid arterial structural wall injury resulting from nonpenetrating trauma. Complete traumatic internal carotid artery occlusion is very rare condition accounting for 0.08~0.4 0f all trauma patients and believed to be associated with the greatest risk of ischemic stroke reported in 50~90% in a few small series. A 55-year-male was admitted with drowsy mentality and severe headache after a fall down accident. Brain computed tomography showed a subdural hematoma at the both frontal area with a fracture of the occipital skull bone. Two days after admission, he suddenly complained with a right side hemiparesis of motor grade 2. Brain magnetic resonance diffusion demonstrated multiple high flow signal changes from the left frontal and parietal lesion. Computed tomographic angiogram (CTA) revealed absence of the left ICA flow. Trans femoral cerebral angiography (TFCA) showed complete occlusion of the left internal carotid artery (ICA) at ophthalmic segment in the left ICA angiogram and flows on the left whole hemispheric lesions through the anterior communicating artery in the right ICA angiogram. We decided to conduct close observations as a treatment for the patient because of acute subdural hematoma and sufficient contralateral cerebral flow by perfusion SPECT scan. Two weeks after the accident, he was treated with heparin anticoagulation within INR 2~4 ranges. He recovered as the motor grade 4 without another neurologic deficit after 3 months.

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A Study on the characteristics of space design in the colonial period in Indonesia (인도네시아 식민시대의 공간양식 특성에 관한 연구)

  • Kang, Yu-Na;Oh, Hye-Kyung
    • Korean Institute of Interior Design Journal
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    • v.20 no.3
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    • pp.190-197
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    • 2011
  • The purpose of this study is to examine the characteristics of space design appearing in facade and interior composition factors of buildings in the colonial period in Indonesia. Research method is a field study, and subjects of the study is 14 buildings built in the colonial period located in Jakarta. The research result is as follows. First, Facade is divided into C type (colonial style), CT type (colonial style + traditional style), CA type (colonial style + art deco style), and CTA type (colonial style + traditional style + art deco style). Among them, CT type which shows both a colonial style and traditional style accounts for the most. As for Java traditional style mainly shows Joglo roof style and bratticing decoration on top of gates, and the colonial style presents both an Amsterdam canal housing style such as narrow Facade and unusual Gable, and a classical style such as pediment, entablature, and columns. Second, interior space is divided into C type (colonial style), CT type (colonial style + Indonesian traditional style), A type (art deco style), and CA type (colonial style + art deco style). Among them, CT type was also accounted for the most. Selected traditional style is a shape of bratticing decoration on top of gates and a shape of tenon of Joglo housing structure. Colonial style showed classical style such as exposed crossbeams, columns, and pilasters, and as for unique decoration, there are Ancona decoration and Delft tile decoration. On one hand, art deco style used typical art deco factors such as contrast of various materials and complementary color or golden color use as well as zigzag or vertical lines and geometric ornament by combining with colonial style or traditional style. It is expected that such research result will be a practical reference data when Korean construction companies or interior design companies advance Indonesia.

Torsional Vibration Control of a Rotating Chamber Shaft System Using Electrorheological Fluid (ER 유체를 이용한 회전식 약실 축계의 비틀림 진동 제어)

  • Lim, Seung-Chul;Kim, Ki-Kap;Kil, Seong-Jin;Shim, Jeong-Soo;Cha, Ki-Up
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.35 no.1
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    • pp.17-24
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    • 2011
  • It is reported that an intermittently rotating chamber system will improve the ratio of firepower to armament space in the case of mid-calibre automatic guns. However, the parallel index, which is a main component of the system, tends to be torsionally flexible due to the low lateral stiffness of cam followers on the index turret. This may cause the shaft system connecting the turret with the chamber prone to considerable residual torsional vibration so that serious misalignment problems occur during ammunition loading and firing processes. Herein, an electrorhelogical (ER) fluid actuator that can suppress such vibrations and the associated semiactive control algorithm are proposed. By mathematical modeling and computer simulations, the performance of the entire system is proved satisfactory.

Dynamic Allocation of Channel Times based on Link Quality of HR-WPAN (HR-WPAN에서 링크 상태에 따른 동적 채널 타임 할당 기법)

  • Kang, Jae-Eun;Byun, Sung-Won;Lee, Jong-Kyu
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.3B
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    • pp.264-273
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    • 2009
  • For IEEE 802.15.3 HR-WPAN, we propose the DABL algorithm that PNC can allocate the channel times to the DEV in super frame in order that system frame throughput is increased and the delay is decreased. In detail, the DABL algorithm allows to dynamically allocate channel time as well as to adaptively apply the modulation and coding scheme based on the link quality of the DEV. In addition, due to the facts that QoS is quite different depending on service types, we provide the DABL algorithm taking into account RT(Real Time) traffic and Non-RT traffic respectively. Finally, we show simulation results of the DABL algorithm compared to the conventional algorithm that the PNC equally allocates channel times to the DEV regardless of the link quality of the DEV.

A Genetic Marker Associated with the A1 Mating Type Locus in Phytophthora infestans

  • KIM KWON-JONG;EOM SEUNG-HEE;LEE SANG-PYO;JUNG HEE-SUN;KAMOUN SOPHIEN;LEE YOUN SU
    • Journal of Microbiology and Biotechnology
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    • v.15 no.3
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    • pp.502-509
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    • 2005
  • Sexual reproduction plays an important role in the biology and epidemiology of oomycete plant pathogens such as the heterothallic species Phytophthora infestans. Recent worldwide dispersal of A2 mating type strains of P. infestans resulted in increased virulence, gene transfer, and genetic variation, creating new challenges for disease management. To develop a genetic assay for mating type identification in P. infestans, we used the Amplified Fragment Length Polymorphism (AFLP) technique. The primer combination E+AT/M+CTA detected a fragment specific to A1 mating type (Mat-A1) of P. infestans. This fragment was cloned and sequenced, and a pair of primers (INF-1, INF-2) were designed and used to differentiate P. infestans Mat-A1 from Mat-A2 strains. The Mat A1-specific fragment was detected using Southern blot analysis of PCR products amplified with primers INF-1 and INF-2 from genomic DNA of 14 P. infestans Mat-A1 strains, but not 13 P. infestans Mat-A2 strains or 8 other isolates representing several Phytophthora spp. Southern blot analysis of genomic DNAs of P. infestans isolates revealed a 1.6 kb restriction enzyme (EcoRI, BamHI, AvaI)-fragment only in Mat-A1 strains. The A1 mating type-specific primers amplified a unique band under stringent annealing temperatures of $63^{\circ}C-64^{\circ}C$, suggesting that this PCR assay could be developed into a useful method for mating type determination of P. infestans in field material.

New Carotid Artery Stenosis Measurement Method Using MRA Images (경동맥 MRA 영상을 이용한 새로운 내경 측정 방법)

  • 김도연;박종원
    • Journal of KIISE:Software and Applications
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    • v.30 no.12
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    • pp.1247-1254
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    • 2003
  • Currently. the north american symptomatic carotid endarterectomy trial, european carotid surgery trial, and common carotid method are used to measure the carotid stenosis for determining candidate for carotid endarterectomy using the projection angiography from different modalities such as digital subtraction angiography. rotational angiography, computed tomography angiography and magnetic resonance angiography. A new computerized carotid stenosis measuring system was developed using MR angiography axial image to overcome the drawbacks of conventional carotid stenosis measuring methods, to reduce the variability of inter-observer and intra-observer. The gray-level thresholding is one of the most popular and efficient method for image segmentation. We segmented the carotid artery and lumen from three-dimensional time-of-flight MRA axial image using gray-level thresholding technique. Using the measured intima-media thickness value of common carotid artery for each cases, we separated carotid artery wall from the segmented carotid artery region. After that, the regions of segmented carotid without artery wall were divided into region of blood flow and plaque. The calculation of carotid stenosis degree was performed as the following; carotid stenosis grading is(area measure of plaque/area measure of blood flow region and plaque) * 100%.