• Journal of the Korea Convergence Society
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• v.8 no.8
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• pp.197-202
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• 2017

Three-dimensional melanin granules of mummy's hair analyzed using high voltage electron microscopy at 1250kV. The melanin granules in the cortex of mummy's hair located in close proximity to the outer of cortex in the adjacent place of the cuticles. A lot of melanin granule performed in this area. It is a distinguished difference from modern human. While it rotated up to 60 degree counter-clockwise and taken a photo per one degree using high voltage electron microscopy. The melanin granule displayed with long elliptical and variable at the size. The size of granule is measured from $0.3{\sim}0.6{\mu}m$ in minimum diameter and $0.5{\sim}1{\mu}m$ in maximum diameter. Conclusionally, high voltage electron microscope has higher resolution and penetration power than conventional transmission electron microscope that could be load biological thick specimen.

• Applied Microscopy
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• v.42 no.2
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• pp.105-109
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• 2012

Electron tomography (ET) of biological specimens is performed from a series of images obtained over a range of tilt angles in a transmission electron microscope. When using the high voltage electron microscope (HVEM), various noises appear in EM images acquired from thick sections by high voltage electron beam. In order to obtain an adequate result in electron tomograms that allow visualization of rather complex and mega-cellular structure such as brain tissue, it is necessary to remove the noise in each original tilt images of thick section. Using band-pass filtering of original tilt images, the filtered images are obtained and used to assemble a reconstructed tomogram. The qualified 3D tomogram from filtered images results in a considerable reduction of the noises compared to conventional tomogram. In conclusion, this study suggests that band-pass filtering is effective to improve the brightness and intensity of HVEM produced tomograms acquired from micron-thick sections of biological specimens.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.5
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• pp.181-188
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• 2008

E-Science Grid is designed to cope with computation-intensive tasks and to manage a huge volume of science data efficiently. However, certain tasks may involve more than one grid can offer in computation capability or incur a long wait time on other tasks. Resource sharing among Grids can solve this problem with proper processing-integrity check via audit. Due to their computing-intensive nature, the processing time of e-Science tasks tends to be long. This potential long wait before an audit failure encourages earlier audit mechanism during execution in order both to prevent resource waste and to detect any problem fast. In this paper, we propose a Light-weight, Adaptive and Reliable Audit, LARA, of processing Integrity for e-Science applications. With the LARA scheme. researchers can verify their processing earlier and fast.

• Applied Microscopy
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• v.37 no.1
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• pp.35-42
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• 2007

The late pupal stage of Drosophila melanogaster occurs immediately before the completion of retinal development, during which the rhabdomere rapidly forms. In this period, the photoreceptor cells were fixed and dehydrated using a high-pressure freezer (HPF) and freeze substitution (FS) technique, which is the most effective in preserving the cell structures, and observed using high-voltage electron microscopy (HVEM) at 1000 KV. The rhabdomere was classified structurally into three types of formation patterns using stereo-tiling image of thick sections. Initially, hexagonal arrays of rhabdomere existed in different angles. In addition, small pieces of rhabdomere could be observed in the cytoplasm of the photoreceptor rolls, which were visible during the profess of rhabdomere formation. In addition, multiple layers of rhabdomere strings were observed. We observed there are at least three types of vesicles related to rhabdomere formation in photoreceptor cells. In addition, it was found that these vesicles initiate the formation of the rhabdomeres during the pupal stage. Collectively, these data suggest that rhabdomeres were mainly formed through vesicles, and that parts of the rhabdomere formed first and then gathered and formed rhabdomeres in the late pupal stage.

• IMMUNE NETWORK
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• v.4 no.2
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• pp.116-122
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• 2004

Background: LIGHT (TNFSF14) is a member of tumor necrosis factor superfamily and is the ligand for TR2 (TNFRSF14/HVEM). LIGHT is known to have proinflammatory roles in atherosclerosis. Methods: To find out the expression pattern of LIGHT in atherosclerotic plaques, immunohistochemical analysis was performed on human carotid atherosclerotic plaque specimens. LIGHT induced atherogenic events using human monocytic cell line THP-1 were also investigated. Results: Immunohistochemical analysis revealed expression of LIGHT and TR2 in foam cell rich regions in the atherosclerotic plaques. Double immunohistochemical analysis further confirmed the expression of LIGHT in foam cells. Stimulation of THP-1 cells, which express TR2, with either recombinant LIGHT or immobilized anti-TR2 monoclonal antibody induced interleukin-8 and matrix metalloproteinase(MMP)-9. Electrophoretic mobility shift assay demonstrated that LIGHT induces nuclear localization of transcription factor, nuclear factor $(NF)-{\kappa}B$. LIGHT induced activation of MMP-9 is mediated by $NF-{\kappa}B$, since treatment of THP-1 cells with the $NF-{\kappa}B$ inhibitor PDTC (pyrrolidine dithiocarbamate) completely blocked the activation of MMP-9. Conclusion: These data indicate that LIGHT is expressed in foam cells in atherosclerotic plaques and is involved in atherogenesis through activation of pro-atherogenic cytokine IL-8 and destabilization of plaque by inducing matrix degrading enzyme.

• Applied Microscopy
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• v.39 no.1
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• pp.79-83
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• 2009

We report a useful method to estimate the electron dose rate which may be a decisive factor to characterize sample properties. Even though most mircoscopes have their own exposure meters, there are several practical concerns when such exposure meters are used to measure the electron dose rate: 1) Specimen should be avoided within the entire area of exposure meter; 2) beam current has to be always recorded whenever the operation mode is changed; 3) the electron dose rate can not be calculated for the beam current beyond the detectable range. To overcome these limitations, we suggest a useful method which utilize a CCD (charge coupled device) camera which is now a popular detector to obtain the final electron micrographs. We have evaluated the CCD sensitivity using the linear relationship between electron current on the exposure meter and counter ratio on the CCD camera which are built in KBSI-HVEM (high voltage electron microscope). Applying the new method, we obtained the CCD sensitivity which are approximately 0.039 counts/$e^-$ and 1.37 counts/$e^-$ for the Top-TV and the HV-GIF CCD cameras, respectively.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.11a
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• pp.100-103
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• 2008

한국기초과학지원연구원(KBSI, Korea Basic Science Institute)에서는 국내 유일의 초고전압투과전자현미경(HVEM, High Voltage Electron Microscopy)을 비롯하여 3대의 일반투과 전자현미경을 보유하고 있다. 전자현미경을 통하여 관찰된 이미지는 각 단계별로 tilting 되어 저장된 이미지로서 관찰자에게 보다 나은 관찰 환경의 구성을 위해 3D로의 reconstruction은 필수 과정이라고 할 수 있겠다. 이 과정 중 카메라 중심에서 벋어난 부분의 왜곡을 워핑기법을 통하여 최대한 감소시킨다. 이런 전처리 과정을 통하여 3D 구조물을 구성하게 되면 초기 이미지를 그대로 사용하는 것보다 한 단계 더 나은 결과물을 얻어낼 수 있다. 이미지 전처리를 이용한 전자현미경 볼륨 랜더링 시스템의 구축은 관찰자에게 보다 편리하며 빠른 실험 환경을 제공하여 줄 수 있고, 이해하기 쉽고 실제 모습에 가까운 형태의 실험 결과물을 접할 수 있게 된다.

• Applied Microscopy
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• v.39 no.2
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• pp.185-189
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• 2009

Studies about the structure of Drosophila melanogaster retinal cell using electron microscopy have been carried out in details since 1960s. However, these results can have limitations in functional research because of two-dimensional structure. In this study, the adult retina of Drosophila melanogaster was investigated by employing high pressure freezing method, serial sections, high voltage electron microscopy, and 3-dimensional reconstruction method. From there results, mitochondria, microtubules, and nuclei were reconstructed as 3-dimensional structure using IMOD program. The 3D structure of these organelles showed that mitochondira mainly located in distal region near lens, and microtubule mainly located in distal and basal region. The 3D reconstruction of these organelles can be used for a critical evaluation in the dynamic change of cellular organelles caused by functional abnormality like retinal degeneration.

• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.560-564
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• 2007

Korea Basic Science Institute(KBSI) has three general electron microscopes including High Voltage Electron Microscope(HVEM) which is the only one in Korea. Observed images through an electron microscope are what they are tilted by each step and saved, offering the more better circumstances for observers, a reconstruction to 3D could be a essential process. In this process, a warping method decreases distortions maximumly of avoided parts of a camera's focus. All these image treatment processes and 3D reconstruction processes are based on an accompaniment of a highly efficient computer, a number of Grid Node Personal computers share this process in a short time and dispose of it. Grid Node Personal computers' purpose is to make an owner can share different each other and various computing resources efficiently and also Grid Node Personal computers is applying to solve problems like a role scheduling needed for a constructing system, a resource management, a security, a capacity measurement, a condition monitoring and so on. Grid Node Personal computers accomplish roles of a highly efficient computer that general individuals felt hard to use, moreover, a image treatment using the warping method becomes a foundation for reconstructing to more closer shape with an real object of observation. Construction of the electron microscope volume 랜더링 system based on Grid Node Personal computer through the warping process can offer more convenient and speedy experiment circumstances to observers, and makes them meet with experiment outcome that is similar to real shapes and is easy to understand.

• Applied Microscopy
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• v.39 no.2
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• pp.73-80
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• 2009

The plastid inclusion has long been known to exist in leaves of numerous plant species, especially in those of flowering plants. Among the inclusions, crystalline bodies are the most frequently distinguished structures of the foliar plastids, however, microtubules and phytoferritins are also reported occasionally. The crystalline inclusions vary in shape, and are located either in the stroma or within intrathylakoidal spaces, whereas microtubules and phytoferritins are more uniform in shape and are formed in the stroma. In crystalline structures, the composing elements exhibit a lattice pattern and/or paralleled tubules that are either bounded by membranes or exist without membrane enclosing. Other types of inclusions have not been shown to be enclosed by any membranous structures. According to the current survey, the plastid inclusion, with the exception of phytoferritins, has been shown to exhibit a crystalline or tubular pattern, and has been reported in more than 56 species of various families. Their occurrence is not restricted to any photosynthetic pathway, but is found to be randomly distributed among C-3, C-4 and CAM species, without phylogenetic relationships. The progress in plastid inclusion research reveals more information about the function and complexity, but the need for characterizing the 3-D structure of the crystalline inclusions also has been acknowledged in previous studies. A 3-D characterization would utilize tilting and tomography of serial sections with appropriate image processing that would provide valuable information on the sub-structures of the crystalline inclusions. In fact, recent studies performed on 3-D reconstruction of the plastid inclusions revealed important information about their comprising elements. In this article, the crystals and microtubules that have been reported in various types of plastids have been reviewed, with special consideration given to their possible sub-cellular function within the plastids.