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Since the discovery of the Y-Ba-Cu-O superconductors, their physical properties have been investigated by various methods. The chemical state of Cu in Y-Ba-Cu-O compounds la one of the greatest issues because the mechanism of superconductivity in Y-Ba-Cu-O is not understood theoretically. We are analyzing X-ray fluorescence spectra of Cu compounds including superconductors, intending to analyze the chemical state of Cu in Y-Ba-Cu-O. As for other 3d transition elements, structures due to unpaired electrons appear clearly on the lower energy side of the Kα1 line of the element. However there are little differences observed among Cu Kα spectra of Cu compounds even if they are measured by a high-resolution two-crystal spectrometer (see Fig. 1). Although Cu is a member of 3d transition elements, its Kα spectrum shows somewhat different behavior compared with other 3d transition elements. This point is one subject we are interested in.
Translational regulation of mRNAs is crucial for promoting various cellular and developmental processes. Pumilio1 (Pum1) has been shown to play key roles in translational regulation of target mRNAs in many systems of diverse organisms. In zebrafish immature oocytes, Pum1 was shown to bind to cyclin B1 mRNA and promote the formation of cyclin B1 RNA granules. This Pum1-mediated RNA granule formation seemed critical to determine the timing of translational activation of cyclin B1 mRNA during oocyte maturation, leading to activation of maturation/M-phase-promoting factor (MPF) at the appropriate timing. Despite its fundamental importance, the mechanisms of translational regulation by Pum1 remain elusive. In this study, we examined the phosphorylation of Pum1 as a first step to understand the mechanisms of Pum1-mediated translation. SDS-PAGE analyses and phosphatase treatments showed that Pum1 was phosphorylated at multiple sites during oocyte maturation. This phosphorylation began in an early period after induction of oocyte maturation, which preceded the polyadenylation of cyclin B1 mRNA. Interestingly, depolymerization of actin filaments in immature oocytes caused phosphorylation of Pum1, disassembly of cyclin B1 RNA granules, and polyadenylation of cyclin B1 mRNA but not translational activation of the mRNA. Overexpression of the Pum1 N-terminus prevented the phosphorylation of Pum1, disassembly of cyclin B1 RNA granules, and translational activation of the mRNA even after induction of oocyte maturation. These results suggest that Pum1 phosphorylation in the early period of oocyte maturation is one of the key processes for promoting the disassembly of cyclin B1 RNA granules and translational activation of target mRNA.
Pneumococcal serotype replacement is an important issue after the introduction of pneumococcal conjugate vaccine (PCV) in children. After the introduction of 13-valent PCV, the incidence of invasive pneumococcal diseases (IPD) caused by Streptococcus pneumoniae serotype 12F (Sp12F) have increased in some countries; however, an outbreak of Sp12F has not reported in the post-13-valent PCV era. We experienced a local outbreak of Sp12F during March through May 2016 in Tsuruoka city, Japan after the introduction of 13-valent PCV in 2013. The IPD patients were two children and seven adults, three of whom died with a rapid disease progress. Although the clear transmission route was not determined, eight of the nine patients (89%) had close contact with children, which suggests that transmitted colonisation of Sp12F among children and adults might be the source of transmission. Continuous monitoring of IPDs, along with the determination of pneumococcal serotypes, is warranted in the post–13-valent PCV era. New IPD control strategies may be needed if this fatal outbreak continues to occur.
In the previous work, it is reported that the Spin-Seebeck effect (SSE), which refer to the generation of a spin current from a temperature gradient, can be enhanced by Fe interface treatment. Here, we investigated the Fe thickness (dFe) dependency of spin-Seebeck voltage (VSSE) and mixing conductance (gr) in Pt/Fe/Bi:YIG/SGGG system. As a result, magnitude of VSSE had a peak at dFe ≓ 1 ML (monolayer , ≓ 0.3 mm), and also increase of gr was saturated at this point. It suggests that VSSE increase with increasing gr when dFe is smaller than 1.0 ML. For the case in which dFe is larger than 1.0ML, however, VSSE decreases due to a spin current decay in Fe layer with a constant gr. These experimental results are consistent with previous theoretical works.
We focused on the stellar age-velocity dispersion relation (AVR). We performed the N-body/SPH simulations to investigate the origin of AVR. As a results, we found that AVR is not consistent with simple stellar heating.
Yttria (Y2O3) films were deposited on stainless steel substrates from ethylenediaminetetraacetic·yttrium·hydrogen (EDTA·Y·H) complexes by flame spraying. The gas mixtures of acetylene-oxygen (C2H2-O2) or hydrogen-oxygen (H2-O2) were used for the combustion flame and the effects of the combustion gas species on Y2O3 films were investigated. Experiments revealed that the particles propelled in the H2-O2 flame had lower temperature and higher velocity compared with the particles in the C2H2-O2 flame. The existence of Y2O3 crystalline phases and complete decomposition of the EDTA·Y·H were confirmed. The porosity of the film was 25% when the H2-O2 flame was used and 32% when the C2H2-O2 flame was used. In addition, the Y2O3 films showed excellent adherability in tape tests. The H2-O2 flame is thus considered suitable for fabricating dense Y2O3 films.
Shiga-toxin-producing Escherichia coli (STEC) infections usually cause haemolytic uraemic syndrome (HUS) equally in male and female children. This study investigated the localization of globotriaosylceramide (Gb3) in human brain and kidney tissues removed from forensic autopsy cases in Japan. A fatal case was used as a positive control in an outbreak of diarrhoeal disease caused by STEC O157:H7 in a kindergarten in Urawa in 1990. Positive immunodetection of Gb3 was significantly more frequent in female than in male distal and collecting renal tubules. To correlate this finding with a clinical outcome, a retrospective analysis of the predictors of renal failure in the 162 patients of two outbreaks in Japan was performed: one in Tochigi in 2002 and the other in Kagawa Prefecture in 2005. This study concludes renal failure, including HUS, was significantly associated with female sex, and the odds ratio was 4·06 compared to male patients in the two outbreaks. From 2006 to 2009 in Japan, the risk factor of HUS associated with STEC infection was analysed. The number of males and females and the proportion of females who developed HUS were calculated by age and year from 2006 to 2009. In 2006, 2007 and 2009 in adults aged >20 years, adult women were significantly more at risk of developing HUS in Japan.
Neutron star mergers are one of the candidate astrophysical site(s) of r-process. Several chemical evolution studies however pointed out that the observed abundance of r-process is difficult to reproduce by neutron star mergers. In this study, we aim to clarify the enrichment of r-process elements in the Local Group dwarf galaxies. We carry out numerical simulations of galactic chemo-dynamical evolution using an N-body/smoothed particle hydrodynamics code, ASURA. We construct a chemo-dynamical evolution model for dwarf galaxies assuming that neutron star mergers are the major source of r-process elements. Our models reproduce the observed dispersion in [Eu/Fe] as a function of [Fe/H] with neutron star mergers with a merger time of 100 Myr. We find that star formation efficiency and metal mixing processes during the first ≲ 300 Myr of galaxy evolution are important to reproduce the observations. This study supports that neutron star mergers are a major site of r-process.
In 2013, an unusual increase of paratyphoid fever cases in travellers returning from Cambodia was reported in Japan. From December 2012 to September 2013, 18 cases of Salmonella Paratyphi A infection were identified. Microbiological analyses revealed that most isolates had the same clonal identity, although the epidemiological link between these cases remains unclear. It was inferred that the outbreak was caused by a common and persistent source in Cambodia that was likely to have continued during 2014. The information of surveillance and laboratory data from cases arising in travellers from countries with limited surveillance systems should be timely shared with the country of origin.
Accumulating evidence suggests an association between gut microbiota and the development of obesity, raising the possibility of probiotic administration as a therapeutic approach. Bifidobacterium breve B-3 was found to exhibit an anti-obesity effect on high-fat diet-induced obesity mice. In the present study, a randomised, double-blind, placebo-controlled trial was conducted to evaluate the effect of the consumption of B. breve B-3 on body compositions and blood parameters in adults with a tendency for obesity. After a 4-week run-in period, the participants were randomised to receive either placebo or a B-3 capsule (approximately 5 × 1010 colony-forming units of B-3/d) daily for 12 weeks. A significantly lowered fat mass was observed in the B-3 group compared with the placebo group at week 12. Improvements were observed for some blood parameters related to liver functions and inflammation, such as γ-glutamyltranspeptidase and high-sensitivity C-reactive protein. Significant correlations were found between the changed values of some blood parameters and the changed fat mass in the B-3 group. These results suggest the beneficial potential of B. breve B-3 in improving metabolic disorders.
We prepared silicon hyperdoped with sulfur by ion-implantation followed by pulsed laser melting. Effects of laser fluence during pulsed laser melting and of post-annealing on the silicon hyperdoped with sulfur are investigated. The structure of hyperdoped layer changes from poly-to mono-crystal with increasing laser fluence. Interface between sulfur-implanted-layer and single-crystal substrate disappear above 1.1 J/cm2. The spectral intensity of mid-infrared (MIR) optical absorption increases with crystallinity and spectral shape depends on whether the melt depth during pulsed laser melting reaches interface between implanted layer and single-crystal silicon substrate or not. The MIR absorption intensity rapidly decreases with thermal annealing temperature and almost disappears at 750 °C. The activation energy of conductivity decreases with increasing laser fluence and further decreases with increasing post thermal-annealing temperature. The insulator-metal transition is observed for the sample annealed at 750 °C. These results indicate that there is no direct correlation between MIR optical absorption band and insulator-metal transition.
We performed 3D N-body/hydrodynamic simulations of local and high-z (z ∼ 2) star-forming galaxies (SFGs) to investigate the structure and kinematic properties of the different ISM phases (i.e., ionized, atomic, and molecular gases). We took into account, for the first time, a fully non-equilibrium radiative cooling by solving the non-equilibrium chemistries of atoms (H, He, C and O) and molecules (H2 and CO), as well as radiative heating, star formation, heating by HII region and supernova explosions.
Two-dimensional electron gas transport properties have been investigated in nitride double-heterostructures. A striking effect has been observed that the two-dimensional electron gas mobility has been drastically enhanced in the AlGaN/GaN/AlGaN double-heterostructure, compared with that in the conventional AlGaN/GaN single-heterostructure. The observed mobility enhancement has been shown to be mainly due to the enhanced polarization-induced electron confinement in the double-heterostructure, and additionally due to the improvement of the interface roughness in the structure. Device operation of an AlGaN/GaN/AlGaN double-heterostructure field effect transistor has been demonstrated: a maximum transconductance of 180 mS/mm has been obtained for a 0.4 μm-gate-length device. In the double-heterostructure using InGaN channel, the increased capacity for the two-dimensional electron gas has been observed. The AlGaN/(In)GaN/AlGaN double-heterostructures are effective for improving the electron transport properties.