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  1. Article: Evaluation of a Generative Adversarial Network to Improve Image Quality and Reduce Radiation-Dose during Digital Breast Tomosynthesis.

    Gomi, Tsutomu / Kijima, Yukie / Kobayashi, Takayuki / Koibuchi, Yukio

    Diagnostics (Basel, Switzerland)

    2022  Volume 12, Issue 2

    Abstract: In this study, we evaluated the improvement of image quality in digital breast tomosynthesis under low-radiation dose conditions of pre-reconstruction processing using conditional generative adversarial networks [cGAN (pix2pix)]. Pix2pix pre- ... ...

    Abstract In this study, we evaluated the improvement of image quality in digital breast tomosynthesis under low-radiation dose conditions of pre-reconstruction processing using conditional generative adversarial networks [cGAN (pix2pix)]. Pix2pix pre-reconstruction processing with filtered back projection (FBP) was compared with and without multiscale bilateral filtering (MSBF) during pre-reconstruction processing. Noise reduction and preserve contrast rates were compared using full width at half-maximum (FWHM), contrast-to-noise ratio (CNR), peak signal-to-noise ratio (PSNR), and structural similarity (SSIM) in the in-focus plane using a BR3D phantom at various radiation doses [reference-dose (automatic exposure control reference dose: AECrd), 50% and 75% reduction of AECrd] and phantom thicknesses (40 mm, 50 mm, and 60 mm). The overall performance of pix2pix pre-reconstruction processing was effective in terms of FWHM, PSNR, and SSIM. At ~50% radiation-dose reduction, FWHM yielded good results independently of the microcalcification size used in the BR3D phantom, and good noise reduction and preserved contrast. PSNR results showed that pix2pix pre-reconstruction processing represented the minimum in the error with reference FBP images at an approximately 50% reduction in radiation-dose. SSIM analysis indicated that pix2pix pre-reconstruction processing yielded superior similarity when compared with and without MSBF pre-reconstruction processing at ~50% radiation-dose reduction, with features most similar to the reference FBP images. Thus, pix2pix pre-reconstruction processing is promising for reducing noise with preserve contrast and radiation-dose reduction in clinical practice.
    Language English
    Publishing date 2022-02-14
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2662336-5
    ISSN 2075-4418
    ISSN 2075-4418
    DOI 10.3390/diagnostics12020495
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: The Biosynthesis of the Pyrimidine Moiety of Thiamin in Halobacterium salinarum.

    Kijima, Yukie / Hayashi, Maria / Yamada, Kazuko / Tazuya-Murayama, Keiko

    Journal of nutritional science and vitaminology

    2016  Volume 62, Issue 2, Page(s) 130–133

    Abstract: The biosynthetic pathway of the pyrimidine moiety of thiamin was studied in the archaean Halobacterium salinarum. Thiamin is biosynthesized from 4-amino-5-hydroxymethyl-2-methylpyrimidine (pyrimidine) and 5-(2-hydroxyethyl)-4-methylthiazole (thiazole). ... ...

    Abstract The biosynthetic pathway of the pyrimidine moiety of thiamin was studied in the archaean Halobacterium salinarum. Thiamin is biosynthesized from 4-amino-5-hydroxymethyl-2-methylpyrimidine (pyrimidine) and 5-(2-hydroxyethyl)-4-methylthiazole (thiazole). The pyrimidine and the thiazole are biosynthesized de novo in microorganisms. The biosynthetic routes of pyrimidine in microorganisms differ between eukaryote and eubacteria. In the eukaryote Saccharomyces cerevisiae, histidine and pyridoxine are the precursors of pyrimidine, while in the eubacterium Escherichia coli, pyrimidine is biosynthesized from 5-aminoimidazole ribonucleotide (AIR), an intermediate of purine biosynthesis. Tracer investigations revealed that [(15)N]-, [1-(13)C]- and [2-(13)C] glycine, precursors of AIR, were incorporated into the pyrimidine in H. salinarum. These results suggested that the biosynthetic route of the pyrimidine in H. salinarum is similar to that of E. coli.
    MeSH term(s) Biosynthetic Pathways ; Escherichia coli/metabolism ; Glycine/metabolism ; Halobacterium salinarum/metabolism ; Histidine/metabolism ; Purines/metabolism ; Pyridoxine/metabolism ; Pyrimidines/metabolism ; Ribonucleotides/metabolism ; Saccharomyces cerevisiae/metabolism ; Thiamine/biosynthesis ; Thiazoles/metabolism
    Chemical Substances Purines ; Pyrimidines ; Ribonucleotides ; Thiazoles ; aminoimidazole ribotide (25635-88-5) ; 2-(4-methyl-1,3-thiazol-5-yl)ethanol (3XYV4I47I8) ; Histidine (4QD397987E) ; pyrimidine (K8CXK5Q32L) ; Pyridoxine (KV2JZ1BI6Z) ; Glycine (TE7660XO1C) ; purine (W60KTZ3IZY) ; Thiamine (X66NSO3N35)
    Language English
    Publishing date 2016
    Publishing country Japan
    Document type Journal Article
    ZDB-ID 191366-9
    ISSN 1881-7742 ; 0301-4800
    ISSN (online) 1881-7742
    ISSN 0301-4800
    DOI 10.3177/jnsv.62.130
    Database MEDical Literature Analysis and Retrieval System OnLINE

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    In stock of ZB MED Cologne/Königswinter

    Zs.B 596: Show issues Location:
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  3. Article ; Online: The Biosynthesis of the Thiazole Moiety of Thiamin in the Archaeon Halobacterium salinarum.

    Hayashi, Maria / Kijima, Yukie / Tazuya-Murayama, Keiko / Yamada, Kazuko

    Journal of nutritional science and vitaminology

    2015  Volume 61, Issue 3, Page(s) 270–274

    Abstract: The biosynthetic pathways of the thiazole moiety of thiamin were studied in the archaeon Halobacterium salinarum. Thiamin is generated by the union of 4-amino-5-hydroxymethyl-2-methylpyrimidine (pyrimidine) and 5-(2-hydroxyethyl)-4-methylthiazole ( ... ...

    Abstract The biosynthetic pathways of the thiazole moiety of thiamin were studied in the archaeon Halobacterium salinarum. Thiamin is generated by the union of 4-amino-5-hydroxymethyl-2-methylpyrimidine (pyrimidine) and 5-(2-hydroxyethyl)-4-methylthiazole (thiazole). The biosynthesis of thiazole is different in facultative anaerobes, aerobes and eukaryotes. In eukaryotes, the C-4, -4', -5, -5' and -5" of the thiazole is biosynthesized from nicotinamide adenine dinucleotide (NAD), with cysteine as S donor and the C-2 and N atoms of glycine. In facultative anaerobic bacteria, such as Escherichia coli, the precursors of the thiazole are the N and C-2 atoms from tyrosine and C-4, -4', -5, -5' and -5" from 1-deoxy-D-xylurose-5-phosphate, again with cysteine as S donor. In aerobic bacteria, such as Bacillus subtilis, L-tyrosine is replaced by glycine. In Archaea, known as the third domain of life, the biosynthetic pathway of thiamin has not yet been elucidated. In the present study in the archaeon H. salinarum, it was shown that both the N and C-2 from glycine are incorporated into the thiazole, rather than the N atom coming from L-tyrosine. These results show that thiazole biosynthesis in H. salinarum more closely resembles the biosynthetic pathway found in eukaryotes.
    MeSH term(s) Biosynthetic Pathways ; Glycine/chemistry ; Halobacterium salinarum/metabolism ; Pyrimidines/biosynthesis ; Thiamine/biosynthesis ; Thiazoles/chemical synthesis
    Chemical Substances 4-amino-5-hydroxymethyl-2-methylpyrimidine ; Pyrimidines ; Thiazoles ; 2-(4-methyl-1,3-thiazol-5-yl)ethanol (3XYV4I47I8) ; Glycine (TE7660XO1C) ; Thiamine (X66NSO3N35)
    Language English
    Publishing date 2015
    Publishing country Japan
    Document type Journal Article
    ZDB-ID 191366-9
    ISSN 1881-7742 ; 0301-4800
    ISSN (online) 1881-7742
    ISSN 0301-4800
    DOI 10.3177/jnsv.61.270
    Database MEDical Literature Analysis and Retrieval System OnLINE

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    In stock of ZB MED Cologne/Königswinter

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  4. Article: The direct precursor of the pyrimidine moiety of thiamin is not urocanic acid but histidine in Saccharomyces cerevisiae.

    Ishida, Shiho / Tazuya-Murayama, Keiko / Kijima, Yukie / Yamada, Kazuko

    Journal of nutritional science and vitaminology

    2007  Volume 54, Issue 1, Page(s) 7–10

    Abstract: The biosynthetic route of the pyrimidine moiety of thiamin is different in prokaryotes and eukaryotes. In prokaryotes, the pyrimidine moiety is synthesized from aminoimidazole ribonucleotide, an intermediate of purine biosynthesis, while in eukaryotes, ... ...

    Abstract The biosynthetic route of the pyrimidine moiety of thiamin is different in prokaryotes and eukaryotes. In prokaryotes, the pyrimidine moiety is synthesized from aminoimidazole ribonucleotide, an intermediate of purine biosynthesis, while in eukaryotes, we have reported that the N-1, C-2, and N-3 atoms of the imidazole ring of histidine are incorporated into N-3, C-4, and the amino group attached to the C-4 atoms of the pyrimidine moiety, respectively, as a unit; the rest of the atoms of the pyrimidine moiety originate from pyridoxine as a unit. It has been reported that urocanic acid, the deaminated compound of histidine, is the direct precursor of the pyrimidine moiety. In the present report, we have investigated whether histidine or urocanic acid is the direct precursor of the pyrimidine moiety in Saccharomyces cerevisiae, using tracer experiments with 1) (13)C-formate and urocanic acid, 2) (15)N-NH(4)Cl and urocanic acid, 3) (15)N-NH(4)Cl and histidine, and 4) (13)C-histidine and urocanic acid. The GC-MS analysis revealed that the incorporation of the (15)N atom of (15)NH(4)Cl was not affected by the presence of urocanic acid, although it was affected by histidine, and the incorporation of (13)C-histidine was not affected by the presence of urocanic acid. These results confirm that histidine is the direct precursor of the pyrimidine moiety of thiamin in S. cerevisiae.
    MeSH term(s) Eukaryotic Cells/metabolism ; Gas Chromatography-Mass Spectrometry ; Histidine/metabolism ; Molecular Structure ; Prokaryotic Cells/metabolism ; Pyrimidines/biosynthesis ; Pyrimidines/chemistry ; Saccharomyces cerevisiae/metabolism ; Thiamine/biosynthesis ; Thiamine/chemistry ; Urocanic Acid/metabolism
    Chemical Substances Pyrimidines ; Histidine (4QD397987E) ; Urocanic Acid (G8D26XJJ3B) ; Thiamine (X66NSO3N35)
    Language English
    Publishing date 2007-11-06
    Publishing country Japan
    Document type Journal Article
    ZDB-ID 191366-9
    ISSN 1881-7742 ; 0301-4800
    ISSN (online) 1881-7742
    ISSN 0301-4800
    DOI 10.3177/jnsv.54.7
    Database MEDical Literature Analysis and Retrieval System OnLINE

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