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326 results on '"Maeyama K"'

1. Evolution of the electrical characteristics of the ATLAS18 ITk strip sensors with HL-LHC radiation exposure range

Author

Fernandez-Tejero, J., Bach, E., Cindro, V., Fadeyev, V., Federicova, P., Fleta, C., Hirose, S., Kroll, J., Mandic, I., Maeyama, K., Mikestikova, M., Poley, L., Stelzer, B., Tuma, P., Ullan, M., and Unno, Y.

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract

The objective of the study is to evaluate the evolution of the performance of the new ATLAS Inner-Tracker (ITk) strip sensors as a function of radiation exposure, to ensure the proper operation of the upgraded detector during the lifetime of the High-Luminosity Large Hadron Collider (HL-LHC). Full-size ATLAS ITk Barrel Short-Strip (SS) sensors with final layout design, ATLAS18SS, have been irradiated with neutrons and gammas, to confirm the results obtained with prototypes and miniature sensors during the development phase. The irradiations cover a wide range of fluences and doses that ITk will experience, going from 1e13 neq/cm2 and 0.49 Mrad, to 1.6e15 neq/cm2 and 80 Mrad. The split irradiation enables a proper combination of fluence and dose values of the HL-LHC, including a 1.5 safety factor. A complete electrical characterization of the key sensor parameters before and after irradiation is presented, studying the leakage current, bulk capacitance, single-strip and inter-strip characteristics. The results confirm the fulfilment of the ATLAS specifications throughout the whole experiment. The study of a wide range of fluences and doses also allows to obtain detailed results, such as the frequency dependence of the bulk capacitance measurements for highly irradiated sensors, or the evolution of the punch-through protection and inter-strip resistance with radiation., Comment: 25th International Workshop on Radiation Imaging Detectors (iWoRiD2024), Lisbon June 30th - July 4th 2024

Published
2024

24. Draft Genome of the Pearl Oyster Pinctada fucata: A Platform for Understanding Bivalve Biology

Author

Takeuchi, T., primary, Kawashima, T., additional, Koyanagi, R., additional, Gyoja, F., additional, Tanaka, M., additional, Ikuta, T., additional, Shoguchi, E., additional, Fujiwara, M., additional, Shinzato, C., additional, Hisata, K., additional, Fujie, M., additional, Usami, T., additional, Nagai, K., additional, Maeyama, K., additional, Okamoto, K., additional, Aoki, H., additional, Ishikawa, T., additional, Masaoka, T., additional, Fujiwara, A., additional, Endo, K., additional, Endo, H., additional, Nagasawa, H., additional, Kinoshita, S., additional, Asakawa, S., additional, Watabe, S., additional, and Satoh, N., additional

Published
2012
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29. Absence of immature mast cells in the skin of Ws/Ws rats with a small deletion at tyrosine kinase domain of the c-kit gene

Author

Onoue, H., Maeyama, K., Nomura, S., Kasugai, T., Tei, H., Kim, H. M., Watanabe, T., and Kitamura, Y.

Subjects
integumentary system, Base Sequence, Receptors, IgE, Molecular Sequence Data, Protein-Tyrosine Kinases, Rats, Mutant Strains, Rats, Blotting, Southern, Proto-Oncogene Proteins c-kit, Proto-Oncogene Proteins, Animals, Tissue Distribution, Mast Cells, RNA, Messenger, Oligonucleotide Probes, Cellular Senescence, Gene Deletion, In Situ Hybridization, Research Article, Histamine, Skin
Abstract

Ws/Ws rats have a small deletion at the tyrosine kinase domain of the c-kit gene, and practically no mast cells were detectable when the tissues were stained with alcian blue. Because alcian blue stains proteoglycans, there is a possibility that immature mast cells that do not contain a sufficient amount of proteoglycans are not detectable by this method. We examined this possibility by using other markers of mast cells. The histamine content in the skin of Ws/Ws rats was 0.3% that of control normal (+/+) rats. Because the number of alcian blue-positive mast cells in the skin of Ws/Ws rats was also 0.3% that of +/+ rats, histamine in the skin seemed to be concentrated to alcian blue-positive mast cells. Mast cells in the skin of +/+ rats express messenger RNA of Fc epsilon RI beta-subunit and c-kit protein. Because c-kit messenger RNA was normally expressed at least in the brain of Ws/Ws rats despite the small deletion, we examined the expression of Fc epsilon RI beta-subunit and c-kit messenger RNA in the skin and stomach of Ws/Ws rats by reverse transcriptase modification of polymerase chain reaction. Expression of either Fc epsilon RI beta-subunit or c-kit messenger RNA in the skin and stomach of Ws/Ws rats was estimated to be less than 1% that of +/+ rats. Moreover no Fc epsilon RI beta-subunit-expressing and no c-kit-expressing cells were detectable in the skin of Ws/Ws rats by in situ hybridization histochemistry. The present result suggests the absence of immature mast cells in tissues of Ws/Ws rats.

Published
1993

39. Cappuccino mutation in an autoimmune-prone strain of mice suggests a role of platelet function in the progression of immune complex crescentic glomerulonephritis.

Author

Yoshida M, Saiga K, Hato T, Iwaki S, Niiya T, Arita N, Komori H, Tsubaki T, Furukawa H, Terada M, Maeyama K, Nemoto K, Nose M, and Ono M

Abstract

OBJECTIVE: Crescent formation in the renal glomerulus is a typical manifestation of progressive glomerulopathy associated with fatal renal failure; therefore, its prevention is of clinical importance. Little is known about the pathogenic mechanism for crescent formation. This study was undertaken in an attempt to identify the events that are critical for crescent formation in immune complex crescentic glomerulonephritis (CGN) by analyzing a novel mutant strain of mice. METHODS: A spontaneous mutant strain of mice was isolated from the autoimmune-prone strain EOD, which stably develops fatal CGN. The mutant phenotypes were assessed histopathologically, hematologically, and immunologically. The mutation was searched for with positional cloning using microsatellite markers. RESULTS: Compared with wild-type EOD (WT-EOD) mice, mutant EOD (mut-EOD) mice showed marked improvement in CGN in conjunction with an improvement in spontaneous mortality. In WT-EOD mice, an inverse correlation between blood urea nitrogen concentration and blood platelet count and massive accumulation of platelets in the glomerulus were evident, suggesting that an accumulation of platelets in the glomerulus contributes to the progression of CGN. The mutant platelets showed an abnormal aggregation in response to collagen and thrombin, associated with a bleeding tendency in mut-EOD mice. Genetic analysis revealed a deleterious mutation in the cappuccino gene (cno), which encodes a protein that belongs to a complex called the biogenesis of lysosome-related organelle complex 1 and is profoundly involved in platelet function. Morphologic examination revealed a partial defect in dense body formation in the delta-granule of platelets. CONCLUSION: The present findings suggest that platelet functions have a critical role in crescent formation in autoimmune GN. [ABSTRACT FROM AUTHOR]

Published
2006
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42. Non-IgG1 Nature of Cutaneous Basophil Hypersensitivity Factor in Contact Sensitivity

Author

Ichiro Katayama, Kiyoshi Nishioka, Atsushi Yamatodani, Toshiaki Doi, and Maeyama K

Subjects
biology, Immunology, hemic and immune systems, chemical and pharmacologic phenomena, Chemotaxis, General Medicine, Basophil, Basophil degranulation, Guinea pig, chemistry.chemical_compound, medicine.anatomical_structure, chemistry, Basophil chemotaxis, Concanavalin A, Delayed hypersensitivity, parasitic diseases, biology.protein, medicine, Immunology and Allergy, Histamine
Abstract

Cutaneous basophil hypersensitivity factor (CBH-F) from the sera of 1-fluoro-2,4-dinitrobenzene contact-sensitized guinea pigs promoted histamine release from bone marrow basophils in the presence of the antigen, dinitrophenylated epidermal microsomes as well as in vivo activity to induce CBH reaction in naive recipients and in vitro activity to mediate antigen-dependent basophil chemotaxis. The amount of histamine released was around 20% of the total release when compared to that of concanavalin A-induced basophil degranulation (50–60%). Divalent cations were required in this reaction because addition of EDTA completely suppressed histamine release from passively sensitized basophils with CBH-F. Though it is not known at present whether the same molecule is involved in basophil chemotaxis and histamine release, this histamine-releasing activity was recovered in the same preparations with basophil chemotactic activity after several purification steps.

Published
1985

43. Ion-Beam-Induced Dual-Tone Imaging of Polyimide via Two-Step Imidization

Author

Suzuki, Y., Maekawa, Y., Yoshida, M., Maeyama, K., and Yonezawa, N.

Abstract

Dual-tone images in polyimide (Kapton) films were prepared by ion beam irradiation of partially imidized polyamic acid (PAA) films followed by alkaline etching in aqueous tetramethylammonium hydroxide (TMAH) solution. The treated films were heated at a final time for thermal stability. In partially imidized PAA films prepared at 150 °C, ion beam irradiation produced a negative hemispheric structured image with 1.0-μm height and 1.5-μm diameter. In contrast, a positive hole pattern with 0.3-μm diameter appeared on the partially imidized PAA film prepared at 145 °C. By determination of the precise imidization degree of precursor polymer films on the basis of adsorption strength of an imide ring C−N bond (1380 cm-1) in an attenuated total reflection infrared (ATR−IR) spectrum, it was revealed that the image mode of the films switches within a narrow range of imidization degree; positive and negative images were obtained from the PAA films with 67−83% and 89−94% imidization degrees, respectively.

Published
2002
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46. Successful Synthesis of Wholly Aromatic Polyketones via Nickel-Mediated Aromatic Coupling Polymerization

Author

Yonezawa, N., Ikezaki, T., Nakamura, H., and Maeyama, K.

Abstract

Novel aromatic polyketones (8a, 8b) without ether linkage in the main chain were successfully synthesized via nickel-mediated aromatic coupling polymerization of bis(chlorobenzoyl)dimethoxybiphenyls (3a, 3b). The polymers affording flexible films were obtained in the reaction where an excess amount of bipyridyl and a stoichiometric amount of the nickel(II) bromide were present. The resulting polyketones (8a, 8b) have sufficiently high molecular weight (inherent viscosity:  0.59 dL/g for polyketone 8a; 0.35 dL/g for polyketone 8b) and a highly amorphous nature with a rather high glass transition temperature:  218 °C for polyketone 8a; 192 °C for polyketone 8b.

Published
2000

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