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We have developed a new half-membrane-electrode assembly (MEA)-type cell that allows us to conduct attenuated total reflectance–Fourier transform infrared (ATR-FTIR) measurements at the Pt/Nafion interface under humidified N2/O2atmosphere. The cell consists of a gas-diffusion type anode placed on a carbon separator with a gas flow field, a Pt film cathode deposited chemically on an Si ATR prism and a Nafion NRE®211 electrolyte sandwiched between them. The construction allows the control of the atmosphere at the cathode by those at the anode viathe electrolyte of 20-μm thickness.An infrared absorption band was observed at 1400–1403 cm−1under humidified oxygen atmosphere in close association with the appearance of ORR current. Its absence under N2atmosphere and insensitivity to the change from H2O to D2O humidification led us to ascribe the band to the O–O vibration of the adsorbed oxygen molecule O2(ads). The band intensity increased with increasing ORR current but decreased significantly in the limiting current region. However, the stability of the species at potentials as high as 1.1 V vs.the reversible hydrogen electrode (RHE) led us to rule out the possibility that the band could be due to adsorbed superoxide O2−. [ABSTRACT FROM AUTHOR]

Porous hydroxyapatite (HAp) ceramics possessing well-controlled porosities and pore sizes were developed by firing apatite-fiber compacts mixed with carbon beads and agar. The total porosities could be controlled in the range from 40 to 85% by varying compaction pressure (20–40 MPa), firing temperature (1000–1300 °C) and carbon/HAp ratio (0/10–10/10 (w/w)). Most of the pores were regarded as open pores. The pore sizes were mainly affected by the carbon-bead diameter (5, 20 or 150 μm) and partly by the compaction pressure and the firing temperature. The pore sizes of the porous HAp ceramics derived from the carbon beads of 150 μm in diameter were distributed in the two separate ranges of several micrometers and more than 100 μm. [ABSTRACT FROM AUTHOR]

RX J0046.5−7308 is a shell-type supernova remnant (SNR) in the Small Magellanic Cloud (SMC). We carried out new 12CO(J = 1–0, 3–2) observations toward the SNR using Mopra and the Atacama Submillimeter Telescope Experiment. We found eight molecular clouds (A–H) along the X-ray shell of the SNR. The typical cloud size and mass are ∼10–15 pc and ∼1000–3000 M☉, respectively. The X-ray shell is slightly deformed and has the brightest peak in the southwestern shell where two molecular clouds A and B are located. The four molecular clouds A, B, F, and G have high intensity ratios of 12CO(J = 3–2)/12CO(J = 1–0) > 1.2, which are not attributable to any identified internal infrared sources or high-mass stars. The H i cavity and its expanding motion are found toward the SNR, which are likely created by strong stellar winds from a massive progenitor. We suggest that the molecular clouds A–D, F, and G and H i clouds within the wind-blown cavity at VLSR = 117.1–122.5 km s−1 are associated with the SNR. The X-ray spectroscopy reveals the dynamical age of yr and the progenitor mass of ≳30 M☉, which is also consistent with the proposed scenario. We determine physical conditions of the giant molecular cloud LIRS 36A using the large velocity gradient analysis with archival data sets of the Atacama Large Millimeter/submillimeter Array; the kinematic temperature is K and the number density of molecular hydrogen is cm−3. The next generation of γ-ray observations will allow us to study the pion-decay γ-rays from the molecular clouds in the SMC SNR. [ABSTRACT FROM AUTHOR]

Charge exchange (CX) is an important process in shock physics because it indicates an interaction between downstream ions and ambient neutral hydrogen, suggesting the presence of a collisionless shock. We present a high-resolution spectroscopy of an X-ray bright spot in a nearby supernova remnant (SNR), the Cygnus Loop, with the Reflection Grating Spectrometer (RGS) on board XMM-Newton. The target is a compact knotty structure called the “southwestern knot” (SW-K) located at the outer edge of the shell, where the blast wave is likely interacting with dense surrounding materials. The RGS spectrum of the SW-K shows details of the line features below ∼1 keV, where we discover a high forbidden-to-resonance line ratio of O vii Heα. The soft-band (10–35 Å) spectrum is well explained by a thermal component with a CX X-ray emission obscured by neutral and ionized absorbers. The presence of the CX X-ray emission will provide new insights into the shock physics of SNRs. The high-resolution spectroscopy also reveals that the CNO, Ne, and Fe abundances are truly lower than the solar values (0.2–0.4 solar) at the SW-K region. Our result gives a clue to solving the previously known “low-abundance problem” reported from a number of evolved SNRs. [ABSTRACT FROM AUTHOR]

We propose a novel scintillation detector design for positron emission tomography (PET), which has depth of interaction (DOI) capability and uses a single-ended readout scheme. The DOI detector contains a pair of crystal bars segmented using sub-surface laser engraving (SSLE). The two crystal bars are optically coupled to each other at their top segments and are coupled to two photo-sensors at their bottom segments. Initially, we evaluated the performance of different designs of single crystal bars coupled to photomultiplier tubes at both ends. We found that segmentation by SSLE results in superior performance compared to the conventional method. As the next step, we constructed a crystal unit composed of a 3  ×  3  ×  20 mm3 crystal bar pair, with each bar containing four layers segmented using the SSLE. We measured the DOI performance by changing the optical conditions for the crystal unit. Based on the experimental results, we then assessed the detector performance in terms of the DOI capability by evaluating the position error, energy resolution, and light collection efficiency for various crystal unit designs with different bar sizes and a different number of layers (four to seven layers). DOI encoding with small position error was achieved for crystal units composed of a 3  ×  3  ×  20 mm3 LYSO bar pair having up to seven layers, and with those composed of a 2  ×  2  ×  20 mm3 LYSO bar pair having up to six layers. The energy resolution of the segment in the seven-layer 3  ×  3  ×  20 mm3 crystal bar pair was 9.3%–15.5% for 662 keV gamma-rays, where the segments closer to the photo-sensors provided better energy resolution. SSLE provides high geometrical accuracy at low production cost due to the simplicity of the crystal assembly. Therefore, the proposed DOI detector is expected to be an attractive choice for practical small-bore PET systems dedicated to imaging of the brain, breast, and small animals. [ABSTRACT FROM AUTHOR]

To prepare garnet (Bi : YIG) composite films with Au particles, we used a repetitive formation method to increase the number density of particles. On increasing the number of repetitions, the diameter distribution of the particles changed. After five repetitions using 5 nm Au films, the diameter distribution separated into two size groups. Shift of wavelength-excited localized surface plasmon resonance is discussed relative to the diameter distribution. In the composite films, enhancement of Faraday rotation associated with surface plasmons was observed. With six repetitions, a maximum enhanced rotation of [?]1.2deg was obtained, which is 20 times larger than that of a single Bi : YIG film. The figures of merit for the composite films are discussed. The thickness of a Bi : YIG composite film working for enhanced Faraday rotation was examined using an ion milling method. [ABSTRACT FROM AUTHOR]

FSH-secreting pituitary adenoma (FSHoma) is often associated with increased levels of serum FSH and ovarian hyperstimulation syndrome (OHSS). The OHSS has historically been attributed to elevated FSH production by the FSHoma; however, some FSHoma patients with OHSS have normal serum FSH levels. OHSS may result not from increased FSH levels, but also from increased bioactivity of the FSH derived from the adenoma. To address this, we measured the FSH bioactivity in the serum of a 40-year-old woman with an FSHoma and OHSS, whose FSH levels were normal. Chinese hamster ovary cells stably expressing FSH receptors were prepared and transfected with a cAMP-responsive element-driven luciferase reporter plasmid. Cells were then treated with recombinant human FSH (rhFSH), the patient’s sera, or sera from controls, collected at different time points, and subjected to a luciferase assay. Luciferase activity was increased in response to rhFSH in a dose-dependent manner. The responsiveness was further augmented by co-addition of a 3-methyl isobutylxanthine, which improved the sensitivity of our assay. Unexpectedly, the serum FSH bioactivity/immunoactivity ratio of the patient was mostly equal to that of normal subjects. This was confirmed with a granulosa cell aromatase assay. This case report suggests that alternate explanations may exist for the OHSS phenotype seen in some FSHoma patients. [ABSTRACT FROM AUTHOR]