[en] Synchrotron radiation has been used in biological and medical experiments for nearly 30 years. Recently, the applications have changed considerably because of the availability of third-generation sources. In imaging experiments, refraction and diffraction of x-ray are now made use of to obtain images with high contrast. Phase-contrast imaging is also employed. In the field of radiation biology, biological effects of microbeam radiation on tissues have been studied extensively and the results show that microbeam may ablate tumors effectively while considerably reducing damages on normal tissues. (author)

[en] SPring-8/SACLA Research Frontiers, covers the outstanding scientific outcomes achieved at SPring-8 and SACLA in 2014 and 2015. Articles in a wide range of scientific fields are included. Most notably, there are more reports each year on experiments performed at SACLA. Articles in SACLA New Apparatus, Upgrades and Methodology describe new technical developments, but more importantly, there are six excellent articles in Life Science, Physical Science and Chemical Science, proving that SACLA is a versatile experimental tool for leading-edge science. Because the scope of the science covered by SPring-8 and SACLA is rapidly expanding, a small change has been made to the index in this issue. This year, the scientific articles are sorted in five major categories. To help readers find articles of their interest, a keyword or key phrase is given to each article. This was not an easy task, since they must attract the attention of readers in particular fields but should not be too specific for readers with a wide scientific interest. The editors put their heads together to find adequate words and phrases. (J.P.N.)

[en] Short communication

[en] Results are reported of static and time-resolved X-ray diffraction studies on muscle fibers using a hard X-ray undulator installed in the Tristan main ring at KEK, as an innovative source of synchrotron radiation more intense and better collimated than that available with the Photon Factory bending-magnet beamline. The low divergence of the source made it possible to obtain high-quality diffraction patterns from static state of muscles, clearly resolving, with an angular resolution of ca. 700 nm, closely spaced diffraction peaks arising from the two symmetrical halves of the thick filaments centered on the M lines in a sarcomere. The detailed analysis of the meridional pattern lead to a more precise modeling of the complicated molecular packing of myosin molecules and C-proteins in the thick filaments. Time-resolved experiments using a focusing mirror aimed to prove crossbridge behaviors in muscle fibers by collecting X-ray diffraction data at a 185 μs time resolution. When sinusoidal length changes at 500 Hz with an amplitude of 0.3% of the muscle length were applied to a bundle of several single fibers during active contraction, the intensity of the 14.5 nm meridional reflection changed out of phase with the tension change during the oscillating length change, contrasting to the response in the rigor muscle. The high time-resolved experiments provided an important insight to the molecular mechanism of force generation in muscle. These studies yield a preview of the expected gains for muscle studies from the more widespread use of undulator radiation at third-generation synchrotron source. (author)

[en] The downsizing of a Johansson-type X-ray fluorescence (XRF) spectrometer has been examined as a way of enhancing detection efficiency with a tolerable loss of energy resolution. A compact spectrometer equipped with a Ge(2 2 0) analyzing crystal with a Rowland radius of 120 mm has been tested with a highly brilliant helical undulator source at BL40XU, SPring-8. The energy resolution obtained for cobalt Kα₁ (6930.32 eV) was 8.8 eV, which is 10-20 times better than that obtained using a Si(Li) detector, and effectively improved the signal-to-background ratio for XRF spectra. The combination of the present spectrometer and a third generation synchrotron source could provide new opportunities for trace analytical applications, which have been difficult so far by conventional synchrotron XRF experiments based on a Si(Li) detector system. The detection limit obtained for solid bulk samples has reached a level of several tens of ppb

[en] The conventional x-ray imaging for soft tissue often produced some adverse effects because of contrast medium and high-dose radiation. This report outlines the recently developed a very sensitive x-ray imaging method called as refraction contrast method or x-ray Schlieren method, which allows to detect density difference and irregularity in the soft tissue. In the apparatus (SPring-8 BL47XU), a light emitted from undulator was monochromatized by two-crystal x-ray spectroscope and x-ray passed through a sample was caught by imaging detector equipped with a combination of relay lens and CCD. When a glass capillary (outer diameter: 660 μm, inner diameter: 220 μm) was used as a measuring sample, it was confirmed that the image through geometrical refraction was obtained. When x-ray images of a dragonfly wing obtained by the Schlieren method (sample-detector distance: 5 m) and the conventional contact method were compared, it was demonstrated that reticulate structure of the wing was clearly observed by the former method but not at all by the latter one. At present, the study on efficacy of the refraction contrast imaging is under way using rodents. (M.N.)

[en] The 2016 issue of SPring-8/SACLA Research Frontiers covers outstanding scientific outcomes of SPring-8 and SACLA in 2015 and 2016. The number of reports on experiments made at SACLA has been increasing since it started operation in 2011. In this issue, there are eight excellent articles (six last year) in Life Science, Physical Science and Chemical Science, proving that SACLA is becoming a common experimental tool for leading-edge sciences. SPring-8/SACLA Research Frontiers is made of two parts. The first is the scientific results (Scientific Frontiers) and the second is additional information on hard and soft infrastructures that support scientific research. (J.P.N.)

No abstract available

[en] SPring-8 Research Frontiers 2013 covers advances made mainly in the second half of 2012 (2012B) and the fi rst half of 2013 (2013A). Remarkable scientific achievements at SPring-8 and SACLA in diverse scientific fields, including industrial applications, are described. The development of accelerators, beamlines, and experimental apparatus, and the present status of the SPring-8 and SACLA facilities are also presented. In addition, the activities using NewSUBARU, which forms an integral part of the research complex, are introduced. Although this report is called SPring-8 Research Frontiers, it is meant to include all activities at the SPring-8 site. This is a historic year for SACLA because this is the fi rst time scientific reports from experiments conducted at SACLA are included. The two reports in Chemical Science are on the photoionization processes caused by a very short, intense X-ray pulse. Such experiments are only possible with the laser pulse of SACLA. Additional information about SACLA’s operational status and ongoing technical developments are described in the Facility Status and Accelerator and Beamline Frontiers, respectively. (J.P.N.)

[en] SPring-8 Research Frontiers 2014 covers outstanding scientific outcomes of SPring-8 made mainly in the last two consecutive research periods, the second half of 2013 (2013B) and the first half of 2014 (2014A). Scientific achievements at SPring-8 and SACLA in a wide range of basic and applied sciences including industrial applications are described. The development of accelerators, beamlines and experimental apparatus, and the present status of the SPring-8 and SACLA facilities are also presented. In addition, the activities using NewSUBARU, which forms an integral part of the SPring-8 research complex, are included. This volume of SPring-8 Research Frontiers has some different features from the previous ones. There are two review articles at the first part of the volume, which are on Earth Science and Cardiovascular Medicine. Advances in these fields made by using SPring-8 in the last few years are summarized. It is planned to have such reviews for next several years to cover a variety of scientific activities at SPring-8. SACLA has been operating for three years now. In this volume, as was the case in last year, two outstanding scientific reports are included in Chemical Sciences. On top of these, the SACLA Accelerators and Beamlines Frontiers section of this volume contains twelve notable developments that have been made since SACLA became operational. As usual in a new facility, many new techniques have been developed and reported for SACLA, but these have not been included in the previous issues of SPring-8 Research Frontiers. Thus, they are all included in this volume. These techniques have been developed for user experiments, so that, I would expect, there will be less articles in this section and more in the Scientific Frontiers sections in future. A similar transition from a technical development phase to an application phase indeed happened in the early days of SPring-8, leading to a vast number of scientific outputs, as partly described in the two opening reviews. A similar course of development is anticipated in SACLA. (J.P.N.)