M Ishii

Japan Synchrotron Radiation Research Institute (JASRI), Tatsuno, Hyōgo, Japan

Are you M Ishii?

Claim your profile

Publications (101)243.57 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: The free-electron laser, first proposed by Madey(1) in 1971, has significantly reduced laser wavelengths to the vacuum ultraviolet(2,3) and soft X-ray regions(4). Recently, an X-ray free-electron laser (XFEL) was operated at 1.2 angstrom at the Linac Coherent Light Source (LCLS)(5). Here, we report the successful generation of sub-angstrom laser light using a compact XFEL source, combining a short-period undulator with an 8 GeVelectron beam. The shortest wavelength attained-0.634 angstrom (63.4 pm)-is four orders of magnitude smaller than the 694 nm generated by Maiman's first laser(6). The maximum power exceeded 10 GW with a pulse duration of 10(-14) s. This achievement will contribute to the widespread use of XFEL sources and provide broad opportunities for exploring new fields in science.
    Nature Photonics 08/2012; 6(8-8):540-544. DOI:10.1038/nphoton.2012.141 · 29.96 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We achieved stable operation of a free-electron laser (FEL) based on the self-amplified spontaneous-emission (SASE) scheme at the SPring-8 Compact SASE Source (SCSS) test accelerator in the extremely ultraviolet region. Saturation of the SASE FEL power has been achieved at wavelengths ranging from 50 to 60 nm. The pulse energy has reached similar to 30 mu J at 60 nm. The observed fluctuation of the pulse energy is about 10% (standard deviation) for several hours, which agrees with the expectation from the SASE theory showing the stable operation of the accelerator. The SASE FEL has been routinely operated to provide photon beams for user experiments over a period of a few weeks. Analysis on the experimental data gave the normalized-slice emittance at the lasing part is around 0.7 pi mm mrad. This result indicates that the normalized-slice emittance of the initial electron beam, 0.6 pi mm mrad in a 90% core part, is kept almost unchanged after the bunch compression process with a compression factor of approximately 300. The success of the SCSS test accelerator strongly encourages the realization of a compact XFEL source.
    Physical Review Special Topics - Accelerators and Beams 07/2009; 12(7-7). DOI:10.1103/PhysRevSTAB.12.070701 · 1.52 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We report an event-synchronized data-acquisition sys-tem for the accelerator control of the SPring-8 XFEL. So far, more than 100 signals from the beam monitoring sys-tems and RF systems have been successfully collected in synchronization with beam cycles of up to 60 Hz at the SCSS test accelerator, an XFEL prototype machine. The collected data could be effectively used for the fast feed-back correction of the beam energy and trajectory. The same scheme will be introduced for the 8-GeV XFEL.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Single-pass free-electron lasers based on self-amplified spontaneous emission1, 2, 3, 4 are enabling the generation of laser light at ever shorter wavelengths, including extreme ultraviolet5, soft X-rays and even hard X-rays6, 7, 8. A typical X-ray free-electron laser is a few kilometres in length and requires an electron-beam energy higher than 10 GeV (refs 6, 8). If such light sources are to become accessible to more researchers, a significant reduction in scale is desirable Here, we report observations of brilliant extreme-ultraviolet radiation from a 55-m-long compact self-amplified spontaneous-emission source, which combines short-period undulators with a high-quality electron source operating at a low acceleration energy of 250 MeV. The radiation power reaches saturation at wavelengths ranging from 51 to 61 nm with a maximum pulse energy of 30 J. The ultralow emittance (0.6 mm mrad) of the electron beam from a CeB6 thermionic cathode9 is barely degraded by a multiple-stage bunch compression system that dramatically enhances the beam current from 1 to 300 A. This achievement expands the potential for generating X-ray free-electron laser radiation with a compact 2-GeV machine.
    Nature Photonics 09/2008; 2(9-9):555-559. DOI:10.1038/nphoton.2008.134 · 29.96 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We have been installing a VMEbus system in the equipment control system of SPring-8 as a main stream. On the other hand, we need a compact control system to handle a few I/O signals or a few motor axes. To construct a low-cost portable system that is easy to set up, we developed a PC/104-Plus-based CPU module with Power over Ethernet (PoE, IEEE 802.3af) capability. It is based on a Renesas Technology SH-4 CPU, which is used for embedded applications requiring both high performance and low power consumption. We ported a Linux 2.6 kernel to the CPU module and set it up to run on the diskless environment of NFSroot. By stacking a dedicated PoE power module onto the CPU module, it runs without an external power supply. The PoE capability provides the advantages of reduced use of power cable and remote power management via power sourcing equipment such as a switching hub. We can choose stackable PC/104 or PC/104-Plus peripheral I/O modules from a variety of commercial products such as analog inputs and outputs or digital inputs/outputs. Therefore, we can assemble a flexible, compact and low-cost embedded-measurement instrument. As a first application, we plan to apply the CPU module to a precise analog-signal measurement. We report the effect of the PoE power source on the precision of measurement.
  • [Show abstract] [Hide abstract]
    ABSTRACT: In situ scanning tunneling microscopy (STM) with highly brilliant hard X-ray irradiation was enabled at SPring-8. To obtain a good signal-to-noise ratio for elemental analysis, an X-ray beam with a limited size of phi 10 mu m was aligned to a specially designed STM stage in ultrahigh vacuum. Despite various types of noises and a large radiation load around the STM probe, STM images Were Successfully observed with atomic resolution. The use of a new system for elemental analysis was also attempted, which was based oil the modulation of tunneling signals rather than emitted electrons. Among tunneling signals, tunneling current was found to be better than tip height as a signal to be recorded, because the former reduces markedly the error of measurement. Oil a Ge nanoisland oil a clean Si(111) surface, the modulation Of tunneling current was achieved by changing the incident photon energy across the Ge absorption edge.
    Japanese Journal of Applied Physics 03/2006; 45(3B):1913-1916. DOI:10.1143/JJAP.45.1913 · 1.06 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Differences in cytotoxic T lymphocyte activity in hepatitis C virus infection may account for the outcome of interferon monotherapy. To investigate this hypothesis, we analysed the response of peripheral CD8(+) T cells that recognized epitopes presented by HLA-A*2402. We synthesized HLA/beta2-microglobulin/peptide complexes using two epitopes. Production of interferon-gamma by CD8(+) T cells in response to plastic-bound monomeric HLA/peptide complex was observed frequently in sustained virus responders (SVR) (n = 13) against all the peptides, NS31296-1304 (the percentage of responding patients, 61.5%) and core 129-137 (53.8%), while no interferon-gamma production was observed in non-responders (NR) (n = 13) for any of the peptides. Tetramer-staining showed the presence of CD8(+) T cells specific for all the peptides except NS31296-1304 in two SVR at the end of interferon monotherapy, although hardly any such cells were found in four NR. Specific killing was observed against peptides NS31296-1304 (3/4) and core 129-137 (1/4) in sustained responders but none in non-responders. These results suggest that the responses of cytotoxic T lymphocytes (CTLs) were induced during interferon therapy in these patients and that interferon-gamma production by CD8(+) T lymphocytes against HCV NS31296-1304 and core 129-137 are well maintained in patients with SVR compared with those with NR. These findings emphasize the importance of the CD8(+) T cell response in controlling HCV infection.
    Clinical & Experimental Immunology 08/2005; 141(1):81-8. DOI:10.1111/j.1365-2249.2005.02018.x · 3.28 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The SPring-8 controls network has maintained accelerator operations in high reliability and shown good performance during the past years. To cope with the increase of loads on the network due to faster data acquisition and the addition of equipment data, networking hardware has been installed in the last few years. The upgraded network replaces the original FDDI backbone and switches with mixed FDDI/gigabit ethernet and Layer-3 switches. It is necessary to keep the double ring topology for the FDDI and introduce link aggregation technology for the gigabit ethernet to maintain the full redundancy and bandwidth of the system. This paper will discuss the network performance of the gigabit ethernet including its latency and redundancy. We also discuss a future plan for the network including Quality-of-Service over the gigabit ethernet.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A message oriented software scheme is used for the SPring-8 beamline control. In the early stage, we developed customized control programs for each beamline. As the number of beamlines increased, however, it became necessary to introduce a general software scheme that cloud handle the control sequence for every beamline. We developed a new server program, Command Interpreter (CI), as a software framework. The CI interprets a high-level compound message issued from client programs and decomposes it to a set of primitive control messages. The message are sent to the VME computers afterwards. For flexibility, the operation sequences specific to the individual baemline component are standardized and defined in the interface definition files. Using the CI, the response time overhead is reduced to 26% and the XAFS measurement time also decreases by about 50%.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Beamline interlock systems (BL-IS) in SPring-8 were constructed for respective beamlines in accordance with their own components. The systems are based on same architecture. On the other hand when the electron beam deviates from the central region of the insertion device (ID), the generated light melts the downstream devices. In order to prevent it, The rfBPM interlock system was constructed. When the rfBPM interlock system detects deviation, it aborts the stored electron beam within 0.8 ms. (C) 2001 Elsevier Science B.V. All rights reserved.
    Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 07/2001; 467:816-819. DOI:10.1016/S0168-9002(01)00462-4 · 1.32 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A stacked compound refractive X-ray lens was designed to produce an efficiently focused (j50:1 mm) beam for high-pressure experiments at SPring-8. High-pressure X-ray diffraction requires an intense, high-energy and monochromatic X-ray beam in order to penetrate the absorptive window of a diamond anvil cell (DAC). Our lens, producing a focal spot of 120 Â 275 mm 2 and a peak gain of 12, is well matched to these requirements. It is composed of many plastic chips made by molding, which allows many identical chips to be made precisely. Other advantages of this lens include high throughput, simple energy tunability and easy installation. # 2001 Elsevier Science B.V. All rights reserved.
    Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 07/2001; 42(42). DOI:10.1016/S0168-9002(01)00541-1 · 1.32 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In SPring-8, beamline control system is constructed with a highly available distributed network system. The socket based communication protocol is used for the beamline control mainly. Beamline users can control the equipment by sending simple control commands to a server process, which is running on a beamline-managing computer (Ohata et al,, SPring-8 beamline control system, ICALEPCS'99, Trieste, Italy, 1999). At the beginning the network was based on the shared topology at all beamlines. Consequently, it has a risk for misapplication of the user's program to access different machines on the network system cross over beamlines. It is serious problem for the SPring-8 beamline control system, because all beamlines controlled with unified software interfaces. We introduced the switching technology and the firewalls to support network access control. Also the virtual networking (VLAN: IEEE 802.1Q) and the gigabit Ethernet technology (IEEE 802.3ab) are introduced. Thus the network security and the reliability are guaranteed at the higher level in SPring-8 beamline. (C) 2001 Elsevier Science B.V. All rights reserved.
    Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 07/2001; 467:825-828. DOI:10.1016/S0168-9002(01)00470-3 · 1.32 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective: a part of patients with primary biliary cirrhosis (PBC) has anti-human carbonic anhydrase II (CA II) autoantibodies, although several contradictional reports followed. Since immunization of mice with CA II results in cholangitis in a susceptible strain, PBC with anti-CA II antibody may have distinct clinical features. Thus, we tested the sera of patients with PBC for anti-CA II antibodies and compared clinical characteristics of PBC patients with and without anti-CA II antibodies in Japanese patients. Methods: anti-CA II antibodies were detected in nine of 50 (18%) PBC patients by immunoblotting. The evaluation of these patients included various clinical parameters, autoantibodies, and immunological backgrounds. Results: the levels of serum liver tests and the prevalence of serum anti-mitochondrial antibody (77.8 vs. 92.7%) were not different between the patients with and without anti-CA II antibody. However, the prevalence of anti-nuclear antibody (ANA) was significantly higher in the patients with anti-CA II antibody than that in the patients without anti-CA II antibody (66.7 vs. 25.6%, P=0.044), although their mean titers were not statistically different. Association of Sjøgren's syndrome tended to be more frequent in the patients with anti-CA II antibody than those without it (33.3 vs. 14.6%, P=0.327). Studies of HLA class I allotype revealed that three of five (60.0%) patients with anti-CA II antibodies and one patients from 34 (3.0%) patients without anti-CA II antibodies had HLA B51 allotype; the difference in the prevalence of this allotype was significant (P=0.004, Pc=0.01), and the prevalence of other HLA class I and HLA DR allotypes was similar between the patients with and those without anti-CA II antibody. Administration of ursodeoxycholic acid (600 mg per day) was accompanied by change in liver tests in a similar way between the two patient groups. Conclusions: These results suggest that, although clinical features are not distinctive, PBC patients with anti-CA II antibody may have a genetic background, which may contribute to a susceptibility to immune-mediated cholangitis.
    Hepatology Research 06/2001; 20(1):18-27. DOI:10.1016/S1386-6346(00)00128-5 · 2.22 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background: The cyclin dependent kinase p21(waf1) plays a crucial role in the regulation of cell cycle. The family of p53 proteins has the ability to induce p21(waf1), whereas p16(INK4a) modulates post-transcriptionally the expression of p21(waf1). Methods: Total 36 hepatocellular carcinomas (HCCs) and 24 paired adjacent liver tissues were evaluated for the following: (1) expression of p21(waf1) and p16(INK4a); (2) that of p21(waf1), p73 and p63 mRNAs; (3) genomic mutations and the loss of heterozygosity of p73 and p53; and (4) frequency of methylation in the 5'CpG promoter region of p16(INK4a). Results: In HCCs compared with the adjacent non-cancerous liver tissues, the expression of p21(waf1) and p16(INK4a) was reduced. Indeed, p21(waf1) was not detected in 36% (8/22) of HCCs in spite of the presence of p21(waf1) mRNA: among them, mutations of p53 gene were found in 50%, whereas a lack of p16(INK4a) expression in all of them. p21(waf1) and p16(INK4a) were reduced in proportion to the degree of methylation in p16(INK4a) gene. p73 did not mutated, and p63 did not expressed in HCCs. Conclusion: Methylation status of p16(INK4a) gene will play a part for reducing constitutive expression of p16(INK4a) and of p21(waf1) coordinately in HCCs.
    Hepatology Research 06/2001; 20(1):52-67. DOI:10.1016/S1386-6346(00)00122-4 · 2.22 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We observed the x-ray-excited optical luminescence (XEOL) of erbium-doped silicon (Si:Er) thin films to make a site-selective x-ray absorption fine structure (XAFS) measurement of an optically active Er atom. The undulator beam was used for the increment of the electron population in the excited state, and following XEOL at an infrared wavelength of 1.54 microm with minimum absorption loss in the host Si was detected. The edge-jump and XAFS oscillation were successfully obtained at the Er L(III)-edge. This spectrum originated from inner-shell excitation and relaxation of only the optically active Er atom, indicating that site-selectivity at an atomic level was achieved.
    Journal of Synchrotron Radiation 04/2001; 8(Pt 2):372-4. DOI:10.1107/S0909049500014564 · 3.02 Impact Factor
  • Gastroenterology 04/2001; 120(5):A356-A356. · 13.93 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The X-ray-excited optical luminescence (XEOL) of erbium-doped silicon (Si:Er) thin film is observed for the site-selective X-ray absorption spectroscopy (XAS) of an optically active Er atom. In order to achieve the site-selectivity at the atomic level, intense X-ray from an undulator is used for the excitation of Er. Indirect excitation caused by X-ray absorption at Si around Er is investigated, and X-ray induced luminescence independent of the inner-shell excitation of Er is observed. A possible mechanism is proposed, in which the formation of an electron-hole pair in Si and the subsequent transfer of recombination energy excite the valence electron of Er. According to this model, energy back-transfer with phonon absorption is used to suppress the indirect excitation, resulting in the site-selective XAS of Er atom.
    Journal of Electron Spectroscopy and Related Phenomena 03/2001; DOI:10.1016/S0368-2048(00)00237-1 · 1.55 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A controlled trial was conducted to compare the efficacy of interferon (IFN) between two groups of patients with type C liver. Thirty-five patients were randomly assigned to group A (17 patients) or group B (18 patients). The former received 3 megaunits (MU) of human lymphoblastoid IFN six days per week for two weeks, followed by three days per week for 50 weeks; the latter group received 6 MU six days per week for two weeks followed by three days per week for 24 weeks. The percentages of biological sustained responders (B-SR) and virological sustained responders (V-SR) were 29.4 and 23.5%, respectively, in group B, and 17.6% for both in group A. The therapeutic effects were not different between two groups. HCV genotype 2 accounted for significantly higher percentage of B-SR and V-SR (both 57.1%, respectively). These findings indicate that IFN is effective in type C cirrhosis with genotype 2.
    Digestive Diseases and Sciences 04/2000; 45(3):575-80. · 2.55 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Alterations in carbohydrate metabolism associated with liver cirrhosis are characterized by a high serum insulin level and prolonged hyperglycemia on oral glucose tolerance test (OGTT). We measured plasma glucose, immunoreactive insulin (IRI), and C-peptide immunoreactivity (CPR) levels during a 75-g OGTT before and after varices obliteration in 10 cirrhotic patients with gastric varices. After obliteration, the indocyanine green retention rate was decreased and the portal flow velocity was increased. A significant decline in plasma glucose and IRI levels was also noted on OGTT. Moreover, the plasma glucose and IRI levels declined at 90 and 120 min in OGTT while they increased progressively by 120 min before obliteration. The levels of CPR were similar before and after treatment. These results indicate that decreased portal flow due to extrahepatic shunt and consequent impairment of insulin metabolism play a role in glucose intolerance observed in cirrhotic patients and that shunt occlusion improves glucose metabolism.
    Digestive Diseases and Sciences 04/2000; 45(3):581-6. DOI:10.1023/A:1005461611262 · 2.55 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: DX state is strongly localized. This nature could be investigated by observing relaxation process of localized electrons to emptied inner shells. We have found two different optical ionization processes of the DX center in AlxGa1−xAs:Se (x=0.33, NSe=5×1017(cm−3)) by using synchrotron radiation (SR). They are tentatively assigned to be a direct lift of an inner-shell electron to the conduction band (CB) followed by a capture of an electron at the DX center to the emptied inner shell (DX−+hν(L, K-edge)→DX0+eCB) and the Auger ionization of one electron of the DX center to the CB followed by a capture of another electron to the emptied inner shell (DX−+hν(L, K-edge)→DX++eCB+evacuum).
    Physica B Condensed Matter 12/1999; 273:781-783. DOI:10.1016/S0921-4526(99)00648-1 · 1.28 Impact Factor

Publication Stats

1k Citations
243.57 Total Impact Points

Institutions

  • 2001–2009
    • Japan Synchrotron Radiation Research Institute (JASRI)
      Tatsuno, Hyōgo, Japan
    • Kurume University
      Куруме, Fukuoka, Japan
    • SPring-8
      Saitama, Saitama, Japan
  • 1994–2001
    • RIKEN
      Вако, Saitama, Japan
  • 1977–1997
    • Hirosaki University
      • • School of Medicine
      • • Department of Neurosurgery
      Khirosaki, Aomori, Japan
  • 1995
    • Osaka University
      Suika, Ōsaka, Japan
  • 1990
    • Hosei University
      • Research Center of Ion Beam Technology
      Edo, Tōkyō, Japan
  • 1980
    • Országos Idegsebészeti Tudományos Intézet
      Budapeŝto, Budapest, Hungary