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Kumada, Takayuki; Nakagawa, Hiroshi; Miura, Daisuke; Sekine, Yurina; Motokawa, Ryuhei; Hiroi, Kosuke; Inamura, Yasuhiro; Oku, Takayuki; Oishi, Kazuki*; Morikawa, Toshiaki*; et al.
Hamon, 34(2), p.50 - 53, 2024/05
Spin-contrast-variation (SCV) small-angle neutron scattering (SANS) enabled us to determine structure of nano-ice crystals that were generated in rapidly frozen sugar solution. In the frozen glucose solution, we found that the nano-ice crystals formed a planar structure with a radius larger than several tens of nanometers and a thickness of 2-3 nm, which was close to the critical nucleation size of ice crystals in supercooled water. This result suggests that the glucose molecules were preferentially bound to a specific face of nano-ice crystals, and then blocked the crystal growth perpendicular to that face.
Aoki, Hiroyuki
Hamon, 33(4), p.142 - 145, 2023/11
Endo, Shunsuke; Okudaira, Takuya*
Hamon, 33(2), p.68 - 72, 2023/05
no abstracts in English
Kawamura, Seiko
Hamon, 33(1), P. 33, 2023/02
no abstracts in English
Kumada, Takayuki; Miura, Daisuke*; Akutsu, Kazuhiro*; Oku, Takayuki; Torikai, Naoya*; Niizeki, Tomotake*
Hamon, 32(4), p.165 - 168, 2022/11
We demonstrated the advantage of spin-contrast-variation neutron reflectometry on the structure analysis of buried interface between resin and porous silica layers. The interface structure was not reproduced by the normal Gaussian model, but by the asymmetric interface model where crosslinked polymer chains neither permeate the pore nor follow the surface roughness of the silica layer.
Metoki, Naoto
Hamon, 32(4), p.173 - 176, 2022/11
Nuclear spin polarization and the hyperfine splitting of Nd compounds were studied by means of neutron scattering. We can determine the magnetic moment from the unusual upturn of the antiferromagnetic Bragg intensities due to the interference with the nuclear spin contribution and the magnetic moment.
Nakagawa, Hiroshi; Matsuo, Tatsuhito*
Hamon, 32(1), p.12 - 15, 2022/02
To elucidate, predict, and control the biological functions of proteins, it is important to clarify their solution structure and dynamics. Small-angle scattering is one of effective methods for examining the changes in their structures and dynamics due to their binding with target molecules under physiological conditions, although its resolution is lower than that of crystallography, which provides structural information at atomic resolution. In addition, neutron spin echo is the only technique that can measure the conformational dynamics of proteins in the Q-region, which is covered by small-angle scattering. In this paper, we will introduce some of our recent studies using small-angle scattering and neutron spin echo.
Matsuo, Tatsuhito*; Nakagawa, Hiroshi
Hamon, 32(1), p.8 - 11, 2022/02
Incoherent neutron scattering is a powerful tool to investigate the dynamics of biomolecules and water. In this article, a new dynamical model called Matryoshka model is first described, which provides detailed information on the motions contained in the phospholipid molecules based on the scattering spectra. In the latter half of the article, a relationship between water activity and water mobility, and the effects of pressure and hydration on protein dynamics are discussed. These studies demonstrate the advancement of analytical methods which provide ever more detailed information for elucidating the mechanism of biological functions.
Osawa, Takahito
Hamon, 31(3), p.117 - 120, 2021/08
Muonic X-ray analysis is an elemental analysis method by detecting characteristic X-rays emitted from muonic atoms and has various advantages, for example, it can detect light elements such as carbon non-destructively. Our research group has been studying to apply this new analytical method to the sample of the asteroid Ryugu brought back by the asteroid explorer Hayabusa2. This paper outlines the research conducted at J-PARC muon facility so far and the preparation status of the experiment on Ryugu samples scheduled to be conducted from June to July 2021. To make this experiment successful, a device with a glove box has been developed that can analyze microsamples in a helium atmosphere, achieving very low background levels.
Osawa, Takahito
Hamon, 31(1), p.7 - 8, 2021/02
Prompt Gamma-ray activation Analysis system (PGA) installed in JRR-3 is explained.
Matsue, Hideaki
Hamon, 31(1), p.3 - 4, 2021/02
no abstracts in English
Osakabe, Toyotaka
Hamon, 31(1), p.14 - 17, 2021/02
no abstracts in English
Kurita, Keisuke; Iikura, Hiroshi
Hamon, 31(1), p.11 - 13, 2021/02
no abstracts in English
Kumada, Takayuki; Motokawa, Ryuhei; Nakagawa, Hiroshi; Oba, Yojiro; Sekine, Yurina
Hamon, 31(1), p.5 - 6, 2021/02
no abstracts in English
Takeda, Masayasu
Hamon, 31(1), p.18 - 19, 2021/02
no abstracts in English
Oigawa, Hiroyuki
Hamon, 31(1), P. 1, 2021/02
We have been proceeding with aseismic reinforcing work of the research reactor JRR-3 at the Nuclear Science Research Institute aiming at its restart in February, 2021. All the users of JRR-3 are kindly requested to create innovation with paying attention to safety. For this purpose, we would like to make improvements in safety management, administration system, exchange of researchers, and so on.
Kumada, Takayuki; Miura, Daisuke*; Akutsu, Kazuhiro*; Suzuki, Junichi*; Torikai, Naoya*
Hamon, 30(4), p.207 - 211, 2020/11
We developed a technique of spin-contrast-variation neutron reflectivity (SCV-NR) for structural analyses of multilayer films. The SCV-NR curves of the polystyrene monolayer film were precisely reproduced using a common set of structural parameters and neutron scattering length density at each proton polarization. This result ensures that SCV-NR curves are not deformed by inhomogeneous PH due to the spin-diffusion mechanism. The number of structural parameters of the lamellar microphase-separated poly(styrene-block-isoprene) thin film is too large to determine with a single unpolarized reflectivity curve only. However, these parameters converged through the global analysis of the SCV-NR curves. In this manner, SCV-NR determines the structure of multilayer films while excluding the incorrect structural model that accidentally accounts for a single unpolarized reflectivity curve only.
Kaneko, Koji; Kakihana, Masashi*; Hedo, Masato*; Nakama, Takao*; Onuki, Yoshichika*
Hamon, 30(3), p.160 - 165, 2020/08
no abstracts in English
Nishimura, Tomoki*; Akiyoshi, Kazunari*; Sekine, Yurina
Hamon, 30(2), p.102 - 105, 2020/05
The development of drug delivery systems (DDS) that enable encapsulation of drugs, selective delivery to target tissues or organs has improved therapeutic effect and reduced side effects. DDS carriers are mainly based on the self-assembled nanoparticles, and their size and shape have significant influences on the therapeutic effect and side effects. However, their small sizes preclude from obtaining structural data with high accuracy by using conventional structural analysis techniques. We thus have analyzed the structures of supramolecular assemblies under the same conditions in actual use by neutron and synchrotron radiation small-angle X-ray scattering. Here, we review our recent studies on the structural analysis of supramolecular assemblies, including nanogels and polymer vesicles using contrast-variation neutron scattering and X-ray small-angle scattering measurements.
Oba, Yojiro
Hamon, 30(2), p.90 - 93, 2020/05
no abstracts in English
