• Molecules and Cells
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• v.43 no.3
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• pp.276-285
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• 2020

Circadian rhythm is an endogenous oscillation of about 24-h period in many physiological processes and behaviors. This daily oscillation is maintained by the molecular clock machinery with transcriptional-translational feedback loops mediated by clock genes including Period2 (Per2) and Bmal1. Recently, it was revealed that gut microbiome exerts a significant impact on the circadian physiology and behavior of its host; however, the mechanism through which it regulates the molecular clock has remained elusive. 3-(4-hydroxyphenyl)propionic acid (4-OH-PPA) and 3-phenylpropionic acid (PPA) are major metabolites exclusively produced by Clostridium sporogenes and may function as unique chemical messengers communicating with its host. In the present study, we examined if two C. sporogenes-derived metabolites can modulate the oscillation of mammalian molecular clock. Interestingly, 4-OH-PPA and PPA increased the amplitude of both PER2 and Bmal1 oscillation in a dose-dependent manner following their administration immediately after the nadir or the peak of their rhythm. The phase of PER2 oscillation responded differently depending on the mode of administration of the metabolites. In addition, using an organotypic slice culture ex vivo, treatment with 4-OH-PPA increased the amplitude and lengthened the period of PER2 oscillation in the suprachiasmatic nucleus and other tissues. In summary, two C. sporogenes-derived metabolites are involved in the regulation of circadian oscillation of Per2 and Bmal1 clock genes in the host's peripheral and central clock machineries.

• Development and Reproduction
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• v.16 no.4
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• pp.265-270
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• 2012

Ethanol actions in the amygdala formation may underlie in part the reinforcing effects of ethanol consumption. Previously a physiological phenomenon in the basolateral amygdala (BLA) that is dependent on neuronal network activity, compound postsynaptic potentials (cPSPs) were characterized. Effects of acute ethanol application on the frequency of cPSPs were subsequently investigated. Whole cell patch clamp recordings were performed from identified projection neurons in a rat brain slice preparation containing the amygdala formation. Acute ethanol exposure had complex effects on cPSP frequency, with both increases and decreases dependent on concentration, duration of exposure and age of the animal. Ethanol produces complex biphasic effects on synaptically-driven network activity in the BLA. These findings may relate to subjective effects of ethanol on arousal and anxiolysis in humans.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2005.10a
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• pp.62-63
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• 2005

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2005.10a
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• pp.62-63
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• 2005

• 대한생식의학회:학술대회논문집
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• 2005.11a
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• pp.139-139
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• 2005

• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.1
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• pp.38-43
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• 2004

We designed and implemented a medical image query system, including a relational database and DBMS (database management system), which can visualize image data and can achieve spatial, attribute, and mixed queries. Image data used in querying can be visualized in slice, MPR(multi-planner reformat), volume rendering, and overlapping on the query system. To reduce spatial cost and processing time in the system. brain images are spatially clustered, by an adaptive Hilbert curve filling, encoded, and stored to its database without loss for spatial query. Because the query is often applied to small image regions of interest(ROI's), the technique provides higher compression rate and less processing time in the cases.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11b
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• pp.904-906
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• 2005

본 논문에서는 뇌 CT 혈관조영영상에서 슬라이스 정보를 이용한 뇌 분할 방법을 제안한다. 뇌 분할 과정은 현재 슬라이스와 이전 슬라이스 간 분할 영역의 크기 정보를 가지고 영역 성장 단계와 전파 단계로 구분하여 수행된다. 영역 성장 단계에서는 이차원 영역성장법을 통해 뇌 분할을 수행하고 누출이 발생하는 슬라이스에 대하여 방사선 투과 기법을 통해 영역보정을 수행한다. 전파 단계에서는 이전 슬라이스에서 분할된 뇌 영역을 현재 슬라이스로 전파함으로써 장벽을 생성하고 장벽 내에서 이차원 영역성장법을 수행함으로써 누출을 최소화한다. 또한 뇌 영역과 유사한 밝기값을 형성하고 있는 미세 요소들을 제거하기 위해 이차원 연결화소군 레이블링 기법을 통해서 최종적으로 뇌 분할을 수행한다. 본 논문의 실험을 위하여 뇌 CT 혈관조영영상을 사용하여 정확한 뇌분할 결과를 얻었다.

• Proceedings of the KSMRM Conference
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• 2002.11a
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• pp.85-85
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• 2002

Purpose： To evaluate the white matter fiber connectivity of normal human using diffusion tensor MRI. Method： Normal young healthy volunteers (2 women and 1 man) and 3 brain tumor patients participated in this study. All studies were performed using a 1.5T Philips Gyroscan Intern system. Diffusion weighted imaging was performed using single-shot echo planar imaging, with navigator echo phase correction and SENSE. Diffusion weighting was performed along six independent axes, using diffusion weighting of b=800s/$\textrm{mm}^2$. 128matrix, 23cm FOV, 2.5mm slice thickness were used for Imaging parameters. Data were processed on a Window-2000 PC equipped with IDL and PRIDE (Philips Medical System). Corticospinal tract was traced from mid-pons level via posterior limb of internal capsule. Corpus callosum, cerebellar peduncles and frontal fibers were traced by fiber tractography.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.05a
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• pp.405-408
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• 2003

영상의 구성물질에 따른 정확한 분할은 질병의 유무를 판단하는데 매우 중요하다. 그러나 영상에서 구성물질들을 정확하게 분할하기란 쉬운 문제가 아니다. 그리고 많은 연구들이 뇌의 실질적인 량을 고려하지 못한 상태서 분할이 이루어지고 있다. 따라서 뇌의 실질적인 량과 비교할 때 가장 근접한 방법 의 개발이 필요하다고 볼 수 있다. 본 논문은 fat을 소거한 T2 영상과 T1 영상을 이용하여 조직에 따르는 명암 분포가 각각 다르게 분포되어 있는 것을 이용하여 평활화한 후 두 영상의 차로 백질, 회백질, 뇌척수액을 분리하는 방법을 제안한다. 이 방법을 이용하여 정상이의 뇌 MR 영상 이용하여 (19 Slice) 백질, 회백질, 뇌척수액을 분리하는 방법을 제시하였다.

• Journal of Korea Multimedia Society
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• v.21 no.2
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• pp.147-157
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• 2018

Alzheimer's disease has the significant factors for the both specific and characteristic features according to the disease progressing that are the volumetry and surface area by the brain hippocampus shrinking and thinning. However, we have suggested a shape analysis to calculate the variance by the roughness, coarseness or uneven surface on 3D MR images. For the reasons we have presented two methods: the first method is the distance calculation from major axis to edge points and the second method is the distance calculation from centroidal point to edge points on a coronal plane. Then we selected the shortest distance and the longest distance in each slice and analyzed the ANOVA and average distances. Consequently we obtained the available and great results by the longest distance of the axial and centroidal point. The results of average distances were 44.85(AD), 45.04(MCI) and 49.31(NC) from the axial points and 39.30(AD), 39.58(MCI) and 44.78(NC) from centroidal points respectively. Finally the distance variations for the easily recognized visualization were shown by the color mapping. This research could be provided an indicator of biomarkers that make diagnosis and prognosis the Alzheimer's diseases in the future.