22 research outputs found

    Yamato nakhlites: Petrography and mineralogy

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    We carried out the petrographical and mineralogical study of new Yamato nakhlites, Yamato 000593 (Y000593), Y000749 and Y000802, with electron probe microanalyser and Fourier transform infrared microspectrometer. Euhedral pyroxenes (En_Fs_Wo_) are the predominant phase with a modal proportion of 75-80 vol% and occur as elongated grains (~1mm x 0.5mm) with thin Fe-rich rims. The chemical composition of the augite cores comprising most of the volume of these pyroxene crystals is homogeneous and nearly identical with those in other nakhlites. Fe-rich rims are present in contact with the mesostasis. Anhedral ferroan olivines (Fa_; 8-18 vol%, ~0.5 mm) and subhedral titanomagnetites (Ab_Or_). Minor phases in the mesostasis are pyrrhotite (Fe_S; smaller than 20μm), apatite (smaller than 20μm), titanomagnetite, Ca-poor pyroxene, fayalitic olivine (Fa_), tridymite and iddingsite. We distinguish these Yamato nakhlites from other nakhlites based on the chemical compositional ranges of the cores and rims of olivine and pyroxene phenocrysts. We suggest that the chemical variations of these minerals for the Yamato nakhlites are intermediate between those of NWA817 and others (Nakhla, Governador Valadares, and Lafayette). The study by Fourier transform infrared microspectrometer of altered phases both on rims and fractures in olivine phenocrysts and in mesostasis revealed the existence of OH-bearing minerals, which might be mixtures of montmorillonite (70%) and goethite (30%). The existence of bubbles in an OH-bearing phase in olivine grains in contact with the fusion crust suggests that the alteration occurred before atmospheric entry (i.e. Martian origin)

    Hospital and clinic cooperation for the treatment of rheumatoid arthritis in Okayama Prefecture, Japan

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    Objective: To survey the current status and problems of cooperation between clinics and hospitals in Okayama Prefecture, Japan for the treatment of rheumatoid arthritis (RA).  Methods: We distributed a questionnaire to 300 of the 983 Okayama Prefecture clinics that had either an internal medicine or orthopedic surgery department, from December 2013 to February 2014. The questionnaire covered practice pattern for RA treatment in clinics, current status of the hospital and clinic cooperation, and acceptance of the biologic therapy.  Results: One hundred clinics responded to the questionnaire. Seventy percent of the clinics reported making referrals to rheumatologists before the initiation of RA treatment, and half of the other 30% of the clinics administered methotrexate as the first-line treatment for RA by their own decision. Sixty-six clinics cooperated with flagship hospitals, conducting medical and laboratory examinations, providing prescriptions, and treating common diseases of patients. These clinics expected the cooperating rheumatologists to follow-up patients every 3 to 6 months and to make the diagnosis, make decisions regarding RA treatment changes, and perform surgery. Seventy-one percent of the clinics responded that cooperation with a hospital is possible even for patients who are administered biologics. As reasons for no cooperation with the flagship hospitals, clinics noted the lack of information about rheumatologists in the area and recent trends in the management of RA.  Conclusion: The current study reported, for the first time, the actual conditions of management of RA in clinics, as well as future problems of hospital and clinic cooperation in Okayama Prefecture

    An Intensity Tensor and Electric Field Gradient Tensor for Fe<sup>3+</sup> at <i>M</i>1 Sites of Aegirine–Augite Using Single-Crystal Mössbauer Spectroscopy

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    An intensity tensor of quadrupole doublets and an electric field gradient tensor for Fe3+ at M1 sites in aegirine–augite ((Ca0.16Na0.86)∑1.02(Mg0.13Fe2+0.04Fe3+0.72 Al0.07)∑0.96Si2.01O6) are determined using single-crystal Mössbauer spectroscopy. The components of the intensity tensor are IXX = 0.670 (19), IYY = 0.353 (14), IXY = −0.113 (37) and IZZ = 0.477 (33). The components of the electric field gradient tensor (VXX, VYY and VZZ) for Fe3+ at M1 sites in aegirine–augite are −5.96 × 109, −4.65 × 1010 and 5.23 × 1010 C/m3, respectively. Comparisons of the intensity tensor of aegirine–augite with those of aegirine and augite (Wo40En45Fs16) that have already been reported and the IXX, IYY, IXY and IZZ intensity tensor components of aegirine–augite in this study are almost the same as those of aegirine, but different from those of augite. While the M2 sites of aegirine–augite and aegirine are fully occupied with Na+ and Ca2+ ions, the M2 sites of augite are not fully occupied with Ca2+. The compositional dependency of the intensity tensor components suggests that the intensity tensor components for Fe3+ at the M1 site of a solid solution between aegirine and augite are dependent on the occupancy of large cations such as Ca2+ and Na+ at M2 sites
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