• 한국정보과학회논문지:소프트웨어및응용
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• 제32권7호
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• pp.612-624
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• 2005

본 논문에서는 PET-CT 뇌 영상융합을 위해 가우시안 가중치 거리지도를 이용한 표면기반 영상정합을 제안한다. 제안방법은 중요 세 단계로 표면 특징점 추출, 가우시안 가중치 거리지도 생성, 가중치기반 유사도 평가로 구성된다. 첫째, PET 영상과 CT 영상에서 삼차원 역 영역성장법을 이용하여 머리영역을 분할하고 머리 영역과 같이 분할된 잡음 영역을 영역성장법기반 레이블링을 이용한 영역 크기 비교를 통해 제거한 후 선명화 처리 필터를 적용하여 머리 표면 특징점을 추출한다. 둘째, CT 영상에서 추출한 표면 특징점에 가우시안 가중치 거리지도를 생성하여 큰 변위에서도 최적의 위치로 견고하게 수렴하도록 한다. 셋째, 가중치기반 상호상관관계는 PET 영상에서 추출한 표면 특징점과 대응되는 CT 영상의 가우시안 가중치 거리지도를 이용하여 최적 위치를 탐색한다. 본 논문에서는 제안방법의 정확성과 견고성 검사를 위해 인공데이타를 이용하고, 수행시간과 육안평가를 위해 임상데이타를 이용한다. 정확성 검사는 임의로 변환된 인공데이타에 제안방법을 적용한 후 추출된 최적화 변환벡터와의 오차를 제곱근평균제곱오차를 이용하여 평가한다. 견고성 검사는 큰 변위와 잡음을 가지는 인공데이타에서 가중치기반 상호상관관계가 최적의 위치에서 최대를 이루는지를 평가한다 실험 결과 제안한 표면기반 영상정합이 기존 표면기반 영상정합보다 정확하고 견고하게 수렴됨을 알 수 있다.

• Molecules and Cells
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• 제28권3호
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• pp.201-207
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• 2009

Silibinin is a polyphenolic flavonoid compound isolated from milk thistle (Silybum marianum), with known hepatoprotective, anticarcinogenic, and antioxidant effects. Herein, we show that silibinin inhibits receptor activator of $NF-{\kappa}B$ ligand (RANKL)-induced osteoclastogenesis from RAW264.7 cells as well as from bone marrow-derived monocyte/macrophage cells in a dose-dependent manner. Silibinin has no effect on the expression of RANKL or the soluble RANKL decoy receptor osteoprotegerin (OPG) in osteoblasts. However, we demonstrate that silibinin can block the activation of $NF-{\kappa}B$, c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein (MAP) kinase, and extracellular signal-regulated kinase (ERK) in osteoclast precursors in response to RANKL. Furthermore, silibinin attenuates the induction of nuclear factor of activated T cells (NFAT) c1 and osteoclast-associated receptor (OSCAR) expression during RANKL-induced osteoclastogenesis. We demonstrate that silibinin can inhibit $TNF-{\alpha}$-induced osteoclastogenesis as well as the expression of NFATc1 and OSCAR. Taken together, our results indicate that silibinin has the potential to inhibit osteoclast formation by attenuating the downstream signaling cascades associated with RANKL and $TNF-{\alpha}$.

• Asian-Australasian Journal of Animal Sciences
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• 제13권11호
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• pp.1529-1535
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• 2000

The aim of the present study was to determine whether brain corticotropin-releasing factor (CRF) and a new peptide, urocortin (UCN) have a direct action in brain mechanisms controlling feed, water and salt intake in sheep. We gave a continuous intracerebroventricular (ICV) infusion of the peptide at a small dose of $5{\mu}g/0.2ml/hr$ for 98.5 hrs from day 1 to day 5 in sheep not exposed to stress. Feed and water intake during ICV infusion of CRF or UCN decreased significantly compared to those during artificial cerebrospinal fluid (CSF) infusion. NaCl intake during infusion of CRF or UCN was the same as that during CSF infusion. Mean carotid arterial blood pressure (MAP) and heart rate during ICV infusion of CRF or UCN were not significantly different from that during CSF infusion. On the other hand, the plasma glucose concentration during ICV infusion of CRF or UCN tended to be higher than that during CSF infusion. These observations indicate that decreased feed intake induced by CRF and UCN infusion is not mediated by the activation of both the pituitary-adrenal axis and the sympathetic nervous system. The results suggested that brain CRF and UCN act directly in brain mechanisms controlling ingestive behavior to decrease feed and water intake, but do not alter salt intake in sheep.

• Journal of Acupuncture Research
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• 제20권1호
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• pp.22-34
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• 2003

Objective : To ascertain whether the concept of the treatment side is associated with changes in the blind spot mapping that represents the brain function. Methods : Among the outpatients who visited to Department of Acupuncture & Moxibustion, National Medical Center from March 2002 to October 2002, we selected 40 clinical trial volunteers that showed right side physiological blind spot more enlarged than left, and underwent the examinations of Department of Opthalmology, National Medical Center for ruling out the pathological conditions. Physiological blind spot maps were used as an integer of brain activity before and after electroacupuncture application on the unilateral ST36 meridian point by dividing 40 subjects into two comparative groups for double-blind controlled study. Results: The significant changes in the blind spots were observed. Electroacupuncture application on the ipsilateral or contralateral ST36 of an enlargement cortical map were associated with the concept of determining the treatment side. In the case of electroacupuncture application on the ipsilateral side of an enlarged blind spot, there were decrease of $4.11{\pm}8.56cm$(17.3%) in blind spot perimetry length(p < 0.05). In the case of contralateral side, there were increase of $3.19{\pm}5.40cm$(13.7%) in blind spot perimetry length(p<0.05). The Differences were statistically significant(p<0.05). Conclusions: We found that eletroacupuncture application was associated with an increase or decrease in the brain function in the view of blind spot changes depending on the treatment side. These results suggest that the traditional acupuncture therapeutic strategy with determining the treatment side has clinical significance in the view of the brain function.

• 한국동물학회지
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• 제38권3호
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• pp.348-355
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• 1995

배추흰나비 유충 뇌에 분포하는 세로토닌 면역반응성 신경원(이하 세로토닌 세포)이 발생에 따라 형태학적으로 어떻게 분화해 나가는지를 조사하였다. 1령 유충뇌와 2령 유충뇌는 각각 20개의 세로토닌 세포를 포함하였다. 1령 유충뇌에서는 세로토닌 면역 반응성 섬유(이하 세로토닌 섬유) 한무리가 뇌교련을 형성하였고 이같은 섬유의 대부분은 반대쪽 중앙 신경망에 종지하였다. 2령 유충의 뇌에서는 세로토닌 섬유의 대부분이 뇌교련을 형성하였고 1령 유충뇌에서 보다는 그들의 수가 더 많이 관찰되었다. 이 섬유의 종말이 형성하는 보다 풍부한 arborization은 중앙 신경망의 상당한 부분을 차지하였다. 3령 유충뇌의 세로토닌 세포는 22개 였고 세로토닌 섬유들의 구성하는 뇌교련수도 3개로 증가되었으며 세로토닌 섬유의 대부분은 뇌교련을 형성하였다. 30개의 세로토닌 섬유뿐만 아니라 뇌의 전후 방향으로 달리는 세로토닌 섬유도 포함하였다.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 추계학술대회
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• pp.537-540
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• 1997

The quantitative comparison of brain architecture across different subjects requires a common coordinate system, with respect to which the spatial variability of features form different individuals can be expressed. We have developed and implemented an image warping technique which is based on an elastic body deformation. The resulting 2D deformation map can be used to quantify anatomic differences between subjects. The technique's accuracy is tested, by warping 2D magnetic resonance images of age seventies into Talairach atlas.

• Investigative Magnetic Resonance Imaging
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• 제23권2호
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• pp.148-156
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• 2019

Hyperglycemia-induced hemichorea (HGHC) is a rare but characteristic hyperkinetic movement disorder involving limbs on one side of the body. In a 75-year-old woman with a left-sided HGHC, conventional brain MR imaging showed very subtle T1-hyperintensity and unique gadolinium enhancement in the basal ganglia contralateral to movements. Multi-parametric MRI was acquired using pulse sequence with quantification of relaxation times and proton density by multi-echo acquisition. Myelin map was reconstructed based on new tissue classification modeling. In this case report of multi-parametric MRI, quantitative measurement of myelin change related to HGHC in brain structures and its possible explanations are presented. This is the first study to demonstrate myelin loss related to hyperglycemic insult in multi-parametric quantitative MR imaging.

• Investigative Magnetic Resonance Imaging
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• 제26권1호
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• pp.1-9
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• 2022

Artificial intelligence (AI) powered by deep learning (DL) has shown remarkable progress in image recognition tasks. Over the past decade, AI has proven its feasibility for applications in medical imaging. Various aspects of clinical practice in neuroimaging can be improved with the help of AI. For example, AI can aid in detecting brain metastases, predicting treatment response of brain tumors, generating a parametric map of dynamic contrast-enhanced MRI, and enhancing radiomics research by extracting salient features from input images. In addition, image quality can be improved via AI-based image reconstruction or motion artifact reduction. In this review, we summarize recent clinical applications of DL in various aspects of neuroimaging.

• Mass Spectrometry Letters
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• 제14권3호
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• pp.57-78
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• 2023

Understanding the chemical composition of the brain helps researchers comprehend various neurological processes effectively. Understanding of the fundamental pathological processes that underpin many neurodegenerative disorders has recently advanced thanks to the advent of innovative bioanalytical techniques that allow high sensitivity and specificity with chemical imaging at high resolution in tissues and cells. Mass spectrometry imaging [MSI] has become more common in biomedical research to map the spatial distribution of biomolecules in situ. The technique enables complete and untargeted delineation of the in-situ distribution characteristics of proteins, metabolites, lipids, and peptides. MSI's superior molecular specificity gives it a significant edge over traditional histochemical methods. Recent years have seen a significant increase in MSI, which is capable of simultaneously mapping the distribution of thousands of biomolecules in the tissue specimen at a high resolution and is otherwise beyond the scope of other molecular imaging techniques. This review aims to acquaint the reader with the MSI experimental workflow, significant recent advancements, and implementations of MSI techniques in visualizing the anatomical distribution of neurochemicals in the human brain in relation to various neurogenerative diseases.

• 정보처리학회논문지B
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• 제9B권1호
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• pp.35-46
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• 2002

뇌파(Electroencephalogram, EEG)는 뇌에서 막대한 수의 뉴런들의 전위차의 합으로 표현되는 시계열 전위차이다. 규칙적인 시간 간격으로 깊이를 가진 전극 측정에 의한 EEG로부터 서로 다른 구조를 가진 뇌에서의 뉴런 집단의 동역학을 평가할 수 있다. 최근에는 비선형 동역학 연구를 통해 뇌 기능 연구를 정량적으로 분석할 수 있는 방법이 개발되고 있다. 본 논문은 뇌파 신호를 분석함에 있어서 독립성분분석(Independent Component Analysis, ICA)의 적합성을 고려해 보았고, 15명의 정상인의 발가락 자극에 대한 EEG 신호에 이를 적용하여 독립 소스들을 분리해 내었다. 또한 Topological Hawing을 이용하여 각각의 독립 소스들의 기여도를 나타내었다. 이를 통하여 EEG에 독립성분분석을 적용함으로써 뇌 활동의 시간적, 공간적 분석이 가능하고 유용함을 나타내었다.