Isothermal switching of perpendicular exchange bias by pulsed high magnetic field

Isothermal switching of a perpendicular exchange bias by a strong pulsed magnetic field has been investigated using a Pt/Co/α-Cr₂O₃ thin film system. The switching of the perpendicular exchange bias is accompanied by the spin reversal of interfacial uncompensated antiferromagnetic Cr spins. We have also demonstrated that the switching of the exchange bias is reversible by changing the pulsed magnetic field direction. The mechanism of the demonstrated switching is discussed from the viewpoint of the spin flop transition of the α-Cr₂O₃ layer.Yu Shiratsuchi, Kohei Wakatsu, Tetsuya Nakamura, Hiroto Oikawa, Satoru Maenou, Yasuo Narumi, Kou Tazoe, Chiharu Mitsumata, Toyohiko Kinoshita, Hiroyuki Nojiri, and Ryoichi Nakatani, Appl. Phys. Lett. 100, 262413 (2012); https://doi.org/10.1063/1.4731643

Detection and in situ switching of unreversed interfacial antiferromagnetic spins in a perpendicular-exchange-biased system

By using the perpendicular-exchange-biased Pt/Co/α-Cr₂O₃ system, we provide experimental evidence that the unreversed uncompensated Cr spins exist at the Co/α-Cr₂O₃ interface. The unreversed uncompensated Cr spin manifests itself in both the vertical shift of an element-specific magnetization curve and the relative peak intensity of soft-x-ray magnetic circular dichroism spectrum. We also demonstrate an in situ switching of the interfacial Cr spins and correspondingly a reversal of the exchange bias without interfacial atomic diffusion. Such switching shows the direct relationship between the interfacial antiferromagnetic spins and origin of the exchange bias. The demonstrated switching of exchange bias would likely offer a new design of advanced spintronics devices, using the perpendicular-exchange-biased system, with low power consumption and ultrafast operation.Y.Shiratsuchi, H.Noutomi, H.Oikawa, et al. Detection and in situ switching of unreversed interfacial antiferromagnetic spins in a perpendicular-exchange-biased system. Physical Review Letters 109, 077202 (2012); https://doi.org/10.1103/PhysRevLett.109.077202

Development of a soft X-ray angle-resolved photoemission system applicable to 100 µm crystals

A soft X-ray angle-resolved photoemission system applicable to 100 µm crystals has been developed

Magnetic-Domain Structure Analysis of Nd-Fe-B Sintered Magnets Using XMCD-PEEM Technique

A combination of X-Ray Magnetic Circular Dichroism and PhotoEmission Electron Microscopy (XMCD-PEEM) was applied to the magnetic domain analysis of Nd-Fe-B sintered magnets. The XMCD-PEEM high-resolution images revealed both the magnetic domain structures and the microstructural morphologies. In the thermally demagnetized state, each grain in a polycrystalline sample exhibits a multidomain structure, which is magnetically coupled across grain boundaries. After the DC field-demagnetization, it changed to a single domain structure. The magnetization vector in each surface grain reversed to the negative direction during the field-demagnetization procedure because of the small coercivity in the surface region. In the present study, we observed this surface domain reversal for the first time by means of XMCD-PEEM imaging method, which is important in order to understand the surface phenomena of Nd-Fe-B magnets

Recent Advances in Sensing Oropharyngeal Swallowing Function in Japan

Dysphagia (difficulty in swallowing) is an important issue in the elderly because it causes aspiration pneumonia, which is the second largest cause of death in this group. It also causes decline in activities of daily living and quality of life. The oral phase of swallowing has been neglected, despite its importance in the evaluation of dysphagia, because adequate protocols and measuring devices are unavailable. However, recent advances in sensor technology have enabled straightforward, non-invasive measurement of the movement of important swallowing-related organs such as the lips and tongue, as well as the larynx. In this article, we report the present state and possibility of clinical application of such systems developed in Japan

コウガクブ トクベツケンキュウ ホウコクショ コウガク ニ オケル リッタイガゾウ カイセキシステム ノ カイハツ オウヨウ ニ カンスル ケンキュウ

The great development of computers and their rconnected terminals is producing the development of image technology and also the easy operation by networks for users. Given assistance of the special fiscal 1988 and 1989 budgets in the Faculty of Engineering, Tokyo Institute of Polytechnics, this project started in cooperation with the laboratories interested in the application of the image information. In order to fulfill graphic functions and image processor simultaneously by one system, which will be the most powerful research tool in the near future, IRIS 4D/50GT graphic computer and NEXUS image processor were purchased and connected with VME BUS so that a part of the multi-functional system was completed. As several analysis about the information of the three-dimensional image were conducted using the system, the abstract is reported

An approach for genogrouping of Japanese isolates of aquabirnaviruses in a new genogroup, VII, based on the VP2/NS junction region

Aquabirnaviruses, represented by Infectious pancreatic necrosis virus (IPNV), have been isolated from epizootics in salmonids and a variety of aquatic animals in the world; six genogroups of aquabirnaviruses have been identified. In comparisons of nucleotide sequences of the VP2/NS junction region, maximum nucleotide diversities of 30·8 % were observed among 93 worldwide aquabirnavirus isolates. A phylogenetic tree revealed the existence of a new genogroup, VII, for Japanese aquabirnavirus isolates from marine fish and molluscan shellfish. Nucleotide diversities between genogroups VII and I–VI were 18·7 % or greater. At the nucleotide level, Japanese IPNV isolates from epizootics in salmonids were nearly identical to a genogroup I strain from the USA or Canada. It is suggested that Japanese IPNV isolates belonging to genogroup I were originally introduced from North American sources, whereas Japanese aquabirnavirus isolates of genogroup VII were from marine aquatic animals indigenous to Japan

Japan Synchrotron Radiation Research Institute and ORCID

“Japan Synchrotron Radiation Research Institute” was presented by <a href="https://orcid.org/0000-0002-8030-0796">Toyohiko Kinoshita</a> (Japan Synchrotron Radiation Research Institute) on April 17, 2018 at the ORCID Japan Member Meeting in Tokyo

Enhanced propagation of fish nodaviruses in BF-2 cells persitently infected with snakehead retrovirus (SnRV)

Fish nodaviruses are causative agents of viral nervous necrosis causing high mortality in cultured marine fishes around the world. The first successful isolation of fish nodavirus was made with SSN-1 cells, which are persistently infected with snakehead retrovirus (SnRV). In the present study, a BF-2 cell line persistently infected with SnRV (PI-BF-2) was established to evaluate the influence of SnRV on the production of fish nodavirus. The PI-BF-2 cells were slightly more slender than BF-2 cells, but no difference was observed in propagation rate between both cell lines. No difference was observed in production of SnRV between PI-BF-2 and SSN-1 cell lines. Although both PI-BF-2 and BF-2 cell lines showed no cytopathic effect (CPE) after inoculation of striped jack nervous necrosis virus (SJNNV) and redspotted grouper nervous necrosis virus (RGNNV), these fish nodaviruses could be amplified in BF-2 cells, and moreover, production of fish nodaviruses in the PI-BF-2 cell line was more than 40 times higher than in BF-2 cells. Thus, it was concluded that BF-2 cell permissiveness to fish nodaviruses was enhanced by persistent infection with SnRV. Furthermore, homologous cDNA to genomic RNA of SJNNV was detected from both PI-BF-2 and SSN-1 cell lines persistently infected with SnRV. The amount of nodavirus cDNA in SJNNV-inoculated PI-BF-2 cells was clearly lower than that in SJNNV-inoculated SSN-1 cells