Associations between Brain Perfusion and Sleep Disturbance in Patients with Alzheimer's Disease

Im, Jooyeon J.,Jeong, Hyeonseok S.,Park, Jong-Sik,Na, Seung-Hee,Chung, Yong-An,Yang, YoungSoon,Song, In-Uk Korean Dementia Association 2017 Dementia and Neurocognitive Disorders Vol.16 No.3

<P><B>Background and Purpose</B></P><P>Although sleep disturbances are common and considered a major burden for patients with Alzheimer's disease (AD), the fundamental mechanisms underlying the development and maintenance of sleep disturbance in AD patients have yet to be elucidated. The aim of this study was to examine the correlation between regional cerebral blood flow (rCBF) and sleep disturbance in AD patients using technetium-99m hexamethylpropylene amine oxime single-photon emission computed tomography (SPECT).</P><P><B>Methods</B></P><P>A total of 140 AD patients were included in this cross-sectional study. Seventy patients were assigned to the AD with sleep loss (SL) group and the rest were assigned to the AD without SL group. SL was measured using the sleep subscale of the Neuropsychiatric Inventory. A whole-brain voxel-wise analysis of brain SPECT data was conducted to compare the rCBF between the two groups.</P><P><B>Results</B></P><P>The two groups did not differ in demographic characteristics, severity of dementia, general cognitive function, and neuropsychiatric symptoms, with the exception of sleep disturbances. The SPECT imaging analysis displayed decreased perfusion in the bilateral inferior frontal gyrus, bilateral temporal pole, and right precentral gyrus in the AD patients with SL group compared with the AD patients without SL group. It also revealed increased perfusion in the right precuneus, right occipital pole, and left middle occipital gyrus in the AD with SL group compared with the AD without SL group.</P><P><B>Conclusions</B></P><P>The AD patients who experienced sleep disturbance had notably decreased perfusion in the frontal and temporal lobes and increased rCBF in the parietal and occipital regions. The findings of this study suggest that functional alterations in these brain areas may be the underlying neural correlates of sleep disturbance in AD patients.</P>

Cerebral Perfusion Changes after Acetyl-L-Carnitine Treatment in Early Alzheimer's Disease Using Single Photon Emission Computed Tomography

Jeong, Hyeonseok S.,Park, Jong-Sik,Yang, YoungSoon,Na, Seung-Hee,Chung, Yong-An,Song, In-Uk Korean Dementia Association 2017 Dementia and Neurocognitive Disorders Vol.16 No.1

<P><B>Background and Purpose</B></P><P>Although acetyl-L-carnitine (ALC) treatment may have beneficial effects on Alzheimer's disease (AD), its underlying neural correlates remain unclear. The purpose of this study was to investigate cerebral perfusion changes after ALC treatment in AD patients using technetium-<SUP>99</SUP>m hexamethylpropylene amine oxime single photon emission computed tomography (SPECT).</P><P><B>Methods</B></P><P>A total of 18 patients with early AD were prospectively recruited and treated with ALC at 1.5 g/day for 1.4±0.3 years. At baseline and follow-up, brain SPECT, Mini-Mental State Examination (MMSE), Clinical Dementia Rating (CDR), Global Deterioration Scale (GDS), and Neuropsychiatric Inventory (NPI) were used to assess participants. After ALC administration, changes in brain perfusion, severity of dementia, cognitive performance, and neuropsychiatric disturbances were examined.</P><P><B>Results</B></P><P>After ALC administration, changes in scores of MMSE, CDR, GDS, and NPI were not statistically significant (<I>p</I>>0.05). Voxel-wise whole-brain image analysis revealed that perfusion was significantly (<I>p</I><0.001) increased in the right precuneus whereas perfusion was reduced in the left inferior temporal gyrus (<I>p</I><0.001), the right middle frontal gyrus (<I>p</I><0.001), and the right insular cortex (<I>p</I>=0.001) at follow-up.</P><P><B>Conclusions</B></P><P>Although previous studies have suggested that AD patients generally demonstrate progressive deterioration in brain perfusion and clinical symptoms, this study reveals that the perfusion of the precuneus is increased in AD patients after ALC administration and their cognitive and neuropsychiatric symptoms are not aggravated. Further studies are warranted to determine the potential association between perfusion increase in the precuneus and clinical symptoms after ALC treatment in AD patients.</P>

Hematological adverse effects of ribavirin in pigs following intramuscular administration

Dong Uk Lee,Sang H. Je,Sung J. Yoo,Tae yong Kwon,Jeong Y. Shin,Jeong J. Byun,Young S. Lyoo 대한수의학회 2016 대한수의학회 학술대회발표집 Vol.2016 No.-

Methane-Augmented Microwave Plasma Burner

Chan Uk Bang,Yong Cheol Hong,Soon Cheon Cho,Uhm, H.S.,Won Ju Yi IEEE 2006 IEEE transactions on plasma science Vol.34 No.5

<P>In this paper, a microwave plasma burner for generating an enlarged high-temperature and large-volume plasma flame by injecting methane gas into the microwave plasma torch was presented. The air microwave plasma torch explosively burned out the hydrocarbon fuel by high atomic oxygen density. It was observed that the volume of the plasma-burner flame was more about ten times than that of the plasma-torch flame, showing an expanded burner flame. In the comparison of flames, while a conventional CH<SUB>4</SUB> burner reveals the flame of blue color, the CH<SUB>4</SUB> microwave plasma burner shows milky white flame. Also, preliminary experiments were carried out by measuring the temperature profiles of flames along axial and radial directions. Also, we measured the combustion efficiency and reduction rate of NO<SUB>2</SUB> for CH<SUB>4</SUB> plasma burner by employing gas chromatography and Fourier transform infrared</P>

다중 메모리 모델의 CLUMP 시스템을 이용하기 위한 병렬 프로그래밍 기법과 성능 평가

이용욱(Yong-Uk LEE),라마크리쉬나(R. S. Ramakrishna) 한국정보과학회 2000 한국정보과학회 학술발표논문집 Vol.27 No.2Ⅲ

클러스터를 구성하는 단위 노드로 SMP가 새로운 대안으로 시장에 등장하였다. 이러한 멀티프로세서 클러스터(CLUMP)는 하나의 시스템에 다중 메모리 구조를 가지는데, CLUMP가 가지는 다중 메모리 구조를 효과적으로 사용하기 위해서 본 논문에서는 중첩된 병렬화 프로그램의 모델을 제안하였다. 중첩된 병렬화 모델은 중첩된 루프 레벨의 병렬화, 중첩된 태스크 레벨의 병렬화, 그리고 다중 중첩된 병렬화로 나뉜다. 본 논문에서는 중첩된 루프 레벨의 병렬화를 실험대상으로 하여 그 성능을 평가하고 단일 메모리 구조의 병렬화 프로그램과 성능을 비교하였다. 실험 결과 시험한 중첩된 병렬화 모델이 단일 메모리 구조의 병렬화 프로그램에 비하여 좋은 성능을 나타내었지만, 실험대상이 된 루프 레벨 병렬화의 잠재적인 특징으로 인해 실행에 참여하는 노드 수가 많아질수록 성능 향상 폭이 감소하는 결과를 보았다. 프로그램의 성능 향상 폭과 확장성은 문제 크기가 클수록 좋은 특성을 보였다.

진행성 간세포암종의 성공적 외과적 절제술 및 장기 생존 예 우심방 종양혈전을 동반한 간세포암종의 수술적 절제

조용범 ( Yong Beom Cho ),이건욱 ( Kuhn Uk Lee ),이효석 ( Hyo Suk Lee ),안혁 ( Hyuk Ahn ),이해원 ( Hae Won Lee ),조응호 ( Eung Ho Cho ),양성훈 ( Sung Hoon Yang ),조재영 ( Jai Young Cho ),이남준 ( Nam Joon Yi ),서경석 ( Kyung Suk S 대한간암학회 2006 대한간암학회지 Vol.6 No.-

온라인 전기자동차의 상용화를 위한 인프라 구축비용 타당성에 대한 연구

송용욱(Yong Uk Song),박상언(Sangun Park),김우주(Wooju Kim),홍준석(June S. Hong),전동규(DongKyu Jeon),이상헌(Sangheon Lee),박종한(Jonghan Park) 한국전자거래학회 2013 한국전자거래학회지 Vol.18 No.1

본 연구는 온라인 전기자동차를 상용화하기 위해 필요한 인프라 구축비용의 타당성을 알아보기 위한 연구이다. 이를 위해 서울시의 버스노선을 대상으로, 온라인 전기자동차 운영을 위해 필요한 인프라의 구축비용에 대해 연구하였다. 현재 전기자동차 운영방식의 대안으로는 OLEV 방식과 PEV 방식이 고려되고 있으며, 각 방식은 충전지 비용과 충전기 비용에서 각기 장점을 갖고 있다. 두 방식의 총비용을 비교하기 위해 본 논문에서는 온라인 전기버스의 급전장치 설치비용을 최소화하기 위한 급전 장치 최적 배치 모형을 제시하였다. 이를 위하여 먼저 버스정류장에 서로 다른 길이의 급전장치를 설치할 경우의 총 설치비용을 최소화하는 혼합정수계획법(Mixed Integer Programming) 모형을 모델링하였다. 모형에서 사용하는 계수를 구하기 위해 각 버스정류장에서의 평균 정차시간을 구하는 시뮬레이터를 개발하였으며, 계산된 계수와 최적화모형을 이용하여 시내버스 노선 전체에 대하여 최적화된 인프라의 배치 개수와 위치를 결정할 수 있는 시스템을 개발하였다. 서울시의 실제 자료를 대상으로 OLEV 방식과 PEV 방식에서의 총비용을 계산하고 비교한 결과 OLEV 방식의 총 비용이 저렴하게 나타났으며, 결과적으로 OLEV 방식의 상용화 타당성을 입증할 수 있었다. This study aims to validate the cost of building the infrastructure to commercialize online electric vehicles. For that purpose, we probe the cost to construct the necessary infrastructure for online electric vehicles regarding Seoul area public bus transit. OLEV and PEV are considered as alternative electric vehicle schemes, and each of them has their own cons and pros in terms of rechargeable battery cost and charger cost. An optimization model which minimizes the cost to install online electric bus feeding devices is proposed in order to compare the total costs of the two alternative schemes. We developed a Mixed Integer Programming model to locate the feeding devices of several different lengths at each bus stops. Furthermore, we implemented a computer simulator to obtain the parameters which will be used in the MIP model and a Web-based system which determines the optimal location of infrastructure for the whole city area from a result of the MIP model. The cost comparison result shows that the total cost of OLEV is cheaper than that of PEV considering the real data of Seoul area public transit, and, as a result, confirms the feasibility of the commercialization of OLEV.

Differences in Brain Glucose Metabolism During Preparation for ¹³¹I Ablation in Thyroid Cancer Patients: Thyroid Hormone Withdrawal Versus Recombinant Human Thyrotropin

Jeong, Hyeonseok S.,Choi, Eun Kyoung,Song, In-Uk,Chung, Yong-An,Park, Jong-Sik,Oh, Jin Kyoung Mary Ann Liebert 2017 Thyroid Vol.27 No.1

Sequential separation of immunoglobulin Y and phosvitin from chicken egg yolk without using organic solvents.

Lee, Hyun Yong,Abeyrathne, E D N S,Choi, Inwook,Suh, Joo Won,Ahn, Dong Uk Poultry Science Association, etc 2014 Poultry science Vol.93 No.10

<P>A study was conducted to develop a simple sequential separation protocol to separate phosvitin and IgY from egg yolk without using organic solvents. Egg yolk was diluted with 2 volumes of distilled water (DW), homogenized, and centrifuged. The precipitant was collected and homogenized with 4 volumes of 10% NaCl (wt/vol) in 0.05 N NaOH solution to extract phosvitin. The pH of the homogenate was adjusted to 4.0 and the precipitate was removed by centrifugation. The supernatant was collected and then heat-treated at 70C for 30 min and centrifuged to remove impurities. The supernatant containing phosvitin was collected, had salts removed, and was concentrated and then freeze-dried. The supernatant from the centrifugation of diluted egg yolk was diluted again with 3 volumes of DW, and the precipitate was removed by centrifugation. The resulting supernatant was concentrated using ultrafiltration and then IgY was precipitated using 20% saturated (NH4)2SO4+ 15% NaCl (wt/vol). The precipitant was collected after centrifugation at 3,400 g for 30 min at 4C and dissolved with DW, had salts removed, and then was freeze-dried. The purity of separated phosvitin and IgY was checked using SDS-PAGE and the proteins were verified using Western blotting. The purity of phosvitin and IgY was 97.2 and 98.7%, and the yield was 98.7 and 80.9%, respectively. The ELISA results indicated that the activities of separated IgY and phosvitin were 96.3 and 98.3%, respectively. This study proved that both phosvitin and IgY can be separated in sequence from egg yolk without using an organic solvent. Also, the method is very simple and has a high potential for scale-up processing.</P>

Experimental Study of Flow Fields around a Perforated Breakwater

Ariyarathne, H.A. Kusalika S.,Chang, Kuang-An,Lee, Jong-In,Ryu, Yong-Uk Korean Society of Ocean Engineers 2012 International journal of ocean system engineering Vol.2 No.1

This study investigates flow fields and energy dissipation due to regular wave interaction with a perforated vertical breakwater, through velocity data measurement in a two-dimensional wave tank. As the waves propagate through the perforated breakwater, the incoming wave energy is reflected back to the ocean, dissipated due to very turbulent flows near the perforations and inside the chamber, and transmitted through the perforations of the breakwater. This transmitted energy is further reduced due to the presence of the perforated back wall. Hence most of the energy is either reflected or dissipated in the vicinity of the structure, and only a small amount of the incoming wave energy is transmitted through the structure. In this study, particle image velocimetry (PIV) technique was employed to measure two-dimensional instantaneous velocity fields in the vicinity of the structure. Measured velocity data was treated statistically, and used to calculate mean flow fields, turbulence intensity and turbulent kinetic energy. For investigation of the flow pattern, time-averaged mean velocity fields were examined, and discussed using the cross-sections through slot and wall for comparison. Flow fields were obtained and compared for various cases with different regular wave conditions. In addition, turbulent kinetic energy was estimated as an approach to understand energy dissipation near the perforated breakwater. The turbulent kinetic energy was distributed against wave height and wave period to see the dependence on wave conditions.