bioimages
Print ISSN : 0919-2719
Volume 7 , Issue 4
Showing 1-5 articles out of 5 articles from the selected issue
Regular Article
  • Jeonghoon Kim, Junyoung Lee, Jeongwhan Lee, Myoungho Lee
    1999 Volume 7 Issue 4 Pages 135-141
    Published: 1999
    Released: October 31, 2020
    JOURNALS FREE ACCESS
    This paper presents a new level adaptive image enhancer for blurred or dark areas in endoscopic images using an adaptive histogram equalization method and an adaptive histogram modification method. In general, conventional simple histogram equalization algorithms can degrade original image quality due to saturation of black or white areas. But the proposed processing can show doctors enhanced image information without blurs in dark areas caused by distance limits that light sources or internal shapes affect. For developing the proposed system, we first defined a classification of histogram patterns in three types for images of blurred or dark areas selected. Then we applied an adaptive histogram equalization method and an adaptive histogram modification method to get a good image quality for degrading areas. Using the proposed level adaptive image enhancing method resulted in more accurate diagnosis.
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  • Akihiro Nakaya, Kenji Yamamoto
    1999 Volume 7 Issue 4 Pages 143-150
    Published: 1999
    Released: October 31, 2020
    JOURNALS FREE ACCESS
    Some mutations in an RNA molecule change the secondary structure from the original one. We have defined a new metric among the secondary structures of the mutants of RNA molecules and implemented in a newly developed secondary structures prediction system which uses multiple processors connected by a local area network. This metric shows non-linearity to the number of mutations: in some cases, only a point mutation makes the secondary structure drastically change, while in others, even with more than 10 points mutations, the structure of the mutant strain is almost the same as that of the original one. A phylogenetic tree was constructed with U1 RNAs of 19 species using this system.
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  • Kyeong-Seop Kim, Chul-Gyu Song
    1999 Volume 7 Issue 4 Pages 151-156
    Published: 1999
    Released: October 31, 2020
    JOURNALS FREE ACCESS
    Magnetic Resonance Angiography (MRA) is now an essential magnetic resonance imaging (MRI) pulse sequence technique especially for the diagnosis of intracranial vessel diseases. The intracranial vessels can be depicted by Maximum Intensity Projection (MIP). MIP projects the individual MRA slice and extracts the maximum intensity in a selected projection ray. However, the small intensity of vessels can be ignored in the projected plane. A 3D surface visualization scheme is proposed to encompass the small intensity of intracranial vessels by enhancing the intensity of vessels and integrating the Marching Cube Iso-surface algorithm into SGI Open Inventor framework. The Open Inventor framework's viewer provides the navigation utilities to depict the vessels vividly with an interactive frame rate.
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  • Masanori Ueda, Hirohisa Abe, Hiroki Kuyama, Hiroaki Nakanishi, Akihiro ...
    1999 Volume 7 Issue 4 Pages 157-161
    Published: 1999
    Released: October 31, 2020
    JOURNALS FREE ACCESS
    A laser-induced fluorescence detection system coupled with a highly sensitive silicon intensified target (SIT) video camera has been successfully applied to the imaging of a band for DNA fragment labeled with fluorescence dye and the visualizing of a separation process in the microchannel fabricated on a chip. We demonstrated that the imaging of the sample injection process is a powerful method for optimizing the electric potentials. Moreover, in microfabricated capillary electrophoresis (μ-CE) devices, continuous observation of the sample separation process is available. This direct imaging method is useful for the study of separation dynamics on μ-CE devices.
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  • Seiji Hasegawa, Mamoru Nakanishi
    1999 Volume 7 Issue 4 Pages 163-165
    Published: 1999
    Released: October 31, 2020
    JOURNALS FREE ACCESS
    We reported a novel cationic cholesterol derivative with a hydroxyethylamino head group, cholesteryl-3β-carboxyamidoethylene-N-hydroxyethyl amine (I), for Iiposome-mediated gene transfection in our previous paper (Okayama et al., 1997). In the present study, we found that the transfection efficiency of plasmid DNAs (luciferase pGL3 gene) by the liposome was much greater than that of the commercially available cationic liposome, Lipofectin, or those of many cationic liposomes containing a cationic cholesterol derivative with a dialkylamino head group at their optimum conditions. Confocal laser scanning microscopy revealed that fluorescein-conjugated antisense oligonucleotides (phosphorothioate) were efficiently transferred by this new cationic liposome into the nucleus of mammalian culture cells (NIH3T3, HeLa, and L929). The results showed that this new cationic cholesterol derivative might be very promising for liposome-mediated gene transfection in vitro and in vivo.
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