• Applied Microscopy
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• 제42권4호
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• pp.200-206
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• 2012

Induction of neurogenesis can occur in the hippocampus in response to various pathological conditions, such as Alzheimer's disease. The aim of this study was to investigate the changes that occur in endogenous neural stem cells in response to amyloid beta $(A{\beta})_{25-35}$-induced neuronal cell damage in organotypic hippocampal slice cultures. Cresyl violet staining and Fluoro-Jade B staining were used to detect neuronal cell damage and changes of mossy fiber terminals were observed by Timm's staining. The immunofl uorescence staining was used to detect the newly generated cells in the subgranular zone (SGZ) of the dentate gyrus with specific marker, 5-bromo-2'-deoxyuridine (BrdU), Ki-67, Nestin, and doublecortin (DCX). In compared to control slices, neuronal cell damage was observed and the mossy fibers were expanded to CA3 area by treatment with $A{\beta}_{25-35}$. Ki-67/Nestin- and BrdU/DCX-positive cells were detected in the SGZ. In conclusion, these results demonstrate that $A{\beta}$-induced neuronal damage results in an increase in endogenous neural stem cells in rat hippocampal slice cultures not only for gliosis but also for neurogenesis.

• 한국광학회:학술대회논문집
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• 한국광학회 2009년도 동계학술발표회 논문집
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• pp.529-530
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• 2009

• Journal of the Korean Wood Science and Technology
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• 제36권2호
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• pp.20-28
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• 2008

This study was carried out to provide the so-called circumferential slicing method for investigating radial distributions of the tangential strains and of moisture contents within the log cross section (LC) of Kalopanax pictus during indoor drying it. While the heartwood showed an almost uniform moisture content distribution in the range of about 50~55% in case of the green wood, it has gradually decreased toward the outer side, showing about 19% of moisture content difference from the innermost slice. Although the moisture gradient along the radial direction has gradually become gentle as drying progresses, the sapwood of the outer side represented the moisture contents below the fiber saturation point after 24 hours of drying while the heartwood in the inner part showed the moisture contents higher than the fiber saturation point. The pith side was laid under the tensile stress after 24 hours of drying, and then gradually decreasing toward the bark side, and showed the distribution being switched again to the tensile stress on the bark side. As the drying has progressed, this trend got more intensified, and finally showed the U-shaped distribution model after 48 hours of drying. The circumferential slice test is considered to be suitable in quantitatively determining the tangential strains and moisture content within a LC.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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• pp.939-941
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• 2017

항공우주 구조물은 경량화를 위하여 복합재의 사용이 증가하고 있다. 이러한 구조물 중 추진기관에 해당하는 발사체 동체의 링 프레임 및 부품은 구조적 파손에 덜 취약한 섬유 강화 복합재를 주로 사용한다. 섬유 강화 복합재의 사용이 증가함에 따라 강성 및 강도의 효율적인 설계 방법에 대한 관심이 높아지고 있다. 본 논문에서는 섬유 강화 복합재 중 2차원 3축 브레이딩 복합재의 단위 체적 형상(Repeating Unit Cell, RUC)에 따른 기계적 강도를 예측하였다. 강도 예측 기법으로 섬유다발의 이산화 기법를 통한 섬유조각(Yarn Slice) 정의, 증분 접근법, 강성저하 모델 등을 사용하였다. 마지막으로 예측된 강도와 시험결과를 비교하여 본 논문에서 정의한 예측 기법의 정확도를 검증하였다.

• 대한자기공명의과학회:학술대회논문집
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• 대한자기공명의과학회 2002년도 제7차 학술대회 초록집
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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.

• 대한본초학회지
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• 제22권2호
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• pp.109-114
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• 2007

Objectives : A morphological classification among Sinomenium acutum, Cocculus trilobus and Aristolochia fangchi was made through microscopic observation. Method : The slice of the tested material made by paraffin section technique was colored with Safranine Malachite Green contrast methods, and then observed and photographed by olymphus-BHT. Result : 1. Fiber bundles of pericycle in S. acutum are like a crescent moon, stone cells were found among fiber bundles, and starch grain and raphides of calcium oxalate were included in parenchyma. 2. C. trilobus has the fiber bundle of pericycle resembling a crescent moon, but does not have the raphidesof calcium oxalate. 3. A. fangchi has the raphides of calcium oxalate, but does not have the fiber bundles of pericycle. 4. Stems and roots of S. acutum arc mostly similar, but only stems have the pith. Conclusion :' C. trilobus and A. fangchi can be distinguished from each other by the fiber bundles of pericycle and the raphides of calcium oxalate.

• 한국지진공학회논문집
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• 제19권5호
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• pp.239-246
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• 2015

Reinforced concrete shear walls are effective for resisting lateral loads imposed by wind or earthquakes. Observed damages of the shear wall in recent earthquakes in Chile(2010) and New Zealand(2011) exceeded expectations. Various analytical models have been proposed in order to incorporate such response features in predicting the inelastic response of RC shear walls. However, the model has not been implemented into widely available computer programs, and has not been sufficiently calibrated with and validated against extensive experimental data at both local and global response levels. In this study, reinforced concrete shear walls were modeled with fiber slices, where cross section and reinforcement details of shear walls can be arranged freely. Nonlinear analysis was performed by adding nonlinear shear spring elements that can represent shear deformation. This analysis result will be compared with the existing experiment results. To investigate the nonlinear behavior of reinforced concrete shear walls, reinforced concrete single shear walls with rectangular wall cross section were selected. The analysis results showed that the yield strength of the shear wall was approximately the same value as the experimental results. However, the yielding displacement of the shear wall was still higher in the experiment than the analysis. The analytical model used in this study is available for the analysis of shear wall subjected to high axial forces.

• Journal of the Optical Society of Korea
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• 제19권6호
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• pp.575-585
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• 2015

Magnetic field in magnetic bearings is the physical medium to realize magnetic levitation, the distribution of the magnetic field determines the operating performance of magnetic bearings. In this paper, a thin-slice Fiber Bragg Grating-Giant Magnetostrictive Material magnetic sensor used for the air gap of magnetic bearings was proposed and tested in the condition of dynamic magnetic field. The static property of the sensor was calibrated and a polynomial curve was fitted to describe the performance of the sensor. Measurement of dynamic magnetic field with different frequencies in magnetic bearings was implemented. Comparing with the finite element simulations, the results showed the DC component of the magnetic field was detected by the sensor and error was less than 5.87%.

• 대한자기공명의과학회:학술대회논문집
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• 대한자기공명의과학회 2002년도 제7차 학술대회 초록집
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• pp.86-86
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• 2002

Purpose： To evaluate the white matter fiber configuration in various developmental CNS anomaly 대상 및 방법： Jubert Syndrome, congenital schizencephaly, callosal agenesis and hemiplegic cerebral palsy patients were evaluated by diffusion tensor MRI. 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=600s/$\textrm{mm}^2$. 128 matrix/zero filled to 256, 23cm FOV, 3mm slice thickness were used for imaging parameters. Data were processed on a Window-2000 PC equipped with IDL and PRIDE (Philips Medical System).

• 펄프종이기술
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• 제36권5호
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• pp.1-10
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• 2004

The geometry of headboxes is of great importance in obtaining good formation, even basis weight profile and fiber orientation. Therefore, many attentions have been made to examine the influence of the geometry of headboxes on the flow behavior. In this study, to evaluate flow behavior in headboxes, three types of turbulence generators were examined using pilot headbox. Velocity profiles in MD and CD were measured using a pressure monitoring system and flow in headboxes was visualized by dye injection method. CD velocity profiles at three different locations inside the slice of Type A headbox showed that the velocity increased downstream to slice exit and had a pattern with four humps due to the persisting wall effect of step diffusors. Results from the evaluation of normalized velocity profile and flow visualization showed that L-shaped Type C headbox caused a large pressure drop but it lacked in flow stabilizing ability.