79 research outputs found

    Piezoelectric properties of high Curie temperature barium titanate-bismuth perovskite-type oxide system ceramics

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    Barium titanate (BaTiO3, BT)-bismuth magnesium titanium oxide [Bi(Mg0.5Ti0.5)O-3, BMT] system ceramics were prepared in an ambient atmosphere in order to increase the Curie temperature (T-c) of BT above 132 degrees C. A single perovskite phase was observed for BT-BMT ceramics with BMT compositions less than 50 mol %, and their relative densities were greater than 94%. Synchrotron measured x-ray diffraction patterns revealed that all the cations in the ceramics were homogeneously distributed. The temperature dependence of the dielectric properties revealed that the BT-BMT system ceramics exhibited relaxorlike characteristics with a dielectric maximum temperature as high as 360 degrees C for the 0.5BT-0.5BMT ceramic. The apparent piezoelectric constant (d*) was 60 pC/N for the 0.4BT-0.6BMT ceramic. Based upon these results, the BT-BMT system shows potential as a new type of lead-free material for high T-c piezoelectric applications

    A humanized mouse model identifies key amino acids for low immunogenicity of H7N9 vaccines

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    Influenza vaccines of H7N9 subtype are consistently less immunogenic in humans than vaccines developed for other subtypes. Although prior immunoinformatic analysis identified T-cell epitopes in H7 hemagglutinin (HA) which potentially enhance regulatory T cell response due to conservation with the human genome, the links between the T-cell epitopes and low immunogenicity of H7 HA remains unknown due to the lack of animal models reproducing the response observed in humans. Here, we utilized a humanized mouse model to recapitulate the low immunogenicity of H7 HA. Our analysis demonstrated that modification of a single H7 epitope by changing 3 amino acids so that it is homologous with a known H3 immunogenic epitope sequence significantly improved the immunogenicity of the H7 HA in the humanized mouse model, leading to a greater than 4-fold increase in HA-binding IgG responses. Thus, we provide experimental evidence for the important contribution of this H7-specific T cell epitope in determining the immunogenicity of an influenza vaccine. Furthermore, this study delineates strategies that can be used for screening and selecting vaccine strains using immunoinformatics tools and a humanized mouse model

    Thermal Infrared Imaging Experiments of C-Type Asteroid 162173 Ryugu on Hayabusa2

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    The thermal infrared imager TIR onboard Hayabusa2 has been developed to investigate thermo-physical properties of C-type, near-Earth asteroid 162173 Ryugu. TIR is one of the remote science instruments on Hayabusa2 designed to understand the nature of a volatile-rich solar system small body, but it also has significant mission objectives to provide information on surface physical properties and conditions for sampling site selection as well as the assessment of safe landing operations. TIR is based on a two-dimensional uncooled micro-bolometer array inherited from the Longwave Infrared Camera LIR on Akatsuki (Fukuhara et al., 2011). TIR takes images of thermal infrared emission in 8 to 12 μm with a field of view of 16×12∘ and a spatial resolution of 0.05∘ per pixel. TIR covers the temperature range from 150 to 460 K, including the well calibrated range from 230 to 420 K. Temperature accuracy is within 2 K or better for summed images, and the relative accuracy or noise equivalent temperature difference (NETD) at each of pixels is 0.4 K or lower for the well-calibrated temperature range. TIR takes a couple of images with shutter open and closed, the corresponding dark frame, and provides a true thermal image by dark frame subtraction. Data processing involves summation of multiple images, image processing including the StarPixel compression (Hihara et al., 2014), and transfer to the data recorder in the spacecraft digital electronics (DE). We report the scientific and mission objectives of TIR, the requirements and constraints for the instrument specifications, the designed instrumentation and the pre-flight and in-flight performances of TIR, as well as its observation plan during the Hayabusa2 mission

    Identification of tumour-associated and germ line p53 mutations in canine mammary cancer

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    Mutations of the tumour suppressor p53 gene are found in a number of spontaneous canine cancers and may contribute to increased cytogenetic alterations and tumour formation. Using reverse transcription and DNA amplification, we isolated p53 cDNA from normal and tumour tissue of ten canine mammary cancer patients. DNA sequencing identified p53 mutations in three of the ten patients. These included tumour-associated p53 gene mutations within exons 2 and 5 and a germ line deletion of exons 3 to 7. These results support a role for p53 inactivation in canine mammary tumour formation and breed predisposition to cancer. Such information could prove invaluable in the successful outbreeding of inherited predisposition to cancer in the dog. A putative polymorphism was also identified at codon 69 in exon 4 and we discuss the possibility that similar polymorphisms may be associated with human breast cancer. © 1999 Cancer Research Campaig

    The CD45+ fraction in murine adipose tissue derived stromal cells harbors immune-inhibitory inflammatory cells

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    金沢大学医薬保健研究域医学系Stromal cells in adipose tissue are useful for repair/regenerative therapy as they harbor a substantial number of mesenchymal stem cells; therefore, freshly isolated autologous uncultured adipose tissue derived stromal cells (u-ADSCs) are useful for regenerative therapy, and obviate the need for mesenchymal stem cells. We evaluated the therapeutic effect of murine u-ADSCs and sorted subsets of u-ADSCs in a concanavalin A (ConA) induced murine model of hepatitis, as well as their characteristics. We found that 10–20% of u-ADSCs expressed the CD45 leukocyte-related antigen. CD68, which is a marker of macrophages (MΦs), was expressed by 50% of CD45+ u-ADSCs. About 90% of CD68+CD45+ cells expressed CD206 antigen, which is a marker of inhibitory M2-type MΦs. Genes related to M2-type MUs were especially more highly expressed by CD45+CD206+ u-ADSCs than by CD45− u-ADSCs. CD45+ u-ADSCs inhibited the expression of cytokines/chemokines and suppressed the proliferation of splenocytes stimulated with ConA. We observed that not only whole u-ADSCs, but also the CD45+ subset of u-ADSCs ameliorated the ConA-induced hepatitis in mice. In conclusion, we show that freshly isolated murine u-ADSCs were effective against acute hepatitis, and CD45+ u-ADSCs acting phenotypically and functionally like M2-type MΦs, contributed to the repair of liver tissue undergoing inflammation. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, WeinheimEmbargo Period 12 month

    Spatial patterns in the diet of the Japanese macaque M acaca fuscata and their environmental determinants

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    Article first published online: 24 AUG 20151. ≪1≫We aimed to ascertain the environmental determinants of the diets of Japanese macaques Macaca fuscata in relation to geographical variables (latitude and elevation) and environmental variables [annual rainfall, mean temperature, snow characteristics and normalized difference vegetation index (We NDVI), a proxy for primary productivity] ≪2≫We collected dietary data from the entire range of Japanese macaques (29 study sites) and extracted each dietary component to determine spatial patterns over the species' range and between forest types. We then conducted model selection to identify the environmental determinants of staple diets and dietary diversity. ≪3≫Japanese macaques' diets were mainly composed of 1) foliage, 2) fruits and seeds, and 3) bark and leaf buds, throughout the entire range. Percentages of bark and buds were greater in deciduous forests than in evergreen forests; significant differences in the proportions of the other two major components and in dietary diversity were not observed in different forest types. ≪4≫Macaques inhabiting forests with higher NDVI and with less snow fed more on fruits and seeds, and a high dietary diversity was observed. In snowy forests, macaques inhabiting higher elevation fed more on foliage, while those inhabiting lower elevations fed mainly on bark and buds. ≪5≫When studying spatial patterns in the feeding behaviour of mammals, both environmental and geographical variables should be treated equally since the effect of environmental variables may be independent of the effect of geographical variables. In addition, more emphasis should be placed on snow characteristics, because snow cover leads to decreased availability of terrestrial food items and to increased energy costs (for locomotion and body temperature regulation), which can affect feeding behaviour and dietary diversity
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