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Iron(II) oxide, wüstite, is the iron oxide with the lowest oxygen content. Under ambient conditions it is metastable for two reasons: (1) it undergoes eutectoid decomposition to Fe and Fe3O4 below ≈570° C, and (2) depending on temperature, it is thermodynamically stable only for very low oxygen partial pressures, down to below 10−20 bar. Hence, for the growth of single crystals from the melt, the growth atmosphere must contain reducing components to keep the oxygen partial pressure on the required low level. With Ar/CO2/CO mixtures this aim can be reached. It is shown experimentally and by thermodynamic calculation, that the grown crystals contain carbon inclusions. Theoretically it is shown that wüstite crystals without carbon inclusions could be grown in humid N2/H2 mixtures. First experiments are presented in this article, but a further adjustment of experimental parameters is required. [ABSTRACT FROM AUTHOR]

K-rich nepheline with a structural formula of A 2 B 6 T 14 T 24 T 34 T 44O32 (Z = 1) within melilite–olivine nephelinite from Hamada, Shimane Prefecture, Japan, was investigated to clarify its crystal structure and to determine cation distributions in the A and B structural positions of structural channels and tetrahedral T 1– T 4 sites. The chemical formula of a single-crystal sample was (Na5.437K2.248Mg0.034Ca0.031)Σ7.750(Si8.332Al7.445Fe3+0.158Ti0.009Cr0.005)Σ15.949O32, which results in 65.2, 27.8, 2.1, 3.2 and 1.6 mol.% NaAlSiO4, KAlSiO4, NaFe3+SiO4, □Si2O4 and □0.5(Ca,Mg)0.5AlSiO4 end-member components, respectively, where □ is a vacancy. X-ray diffraction data of a single crystal with dimensions of 0.28 mm × 0.15 mm × 0.05 mm measured at 296 K indicate the space group P 63. In the structural refinement, the R 1 factor was reduced to 3.69% by taking twinning by merohedry into the refinement. The refinement accounted for 77.7% of the absolute structure and 22.3% of the a and b axes reversed absolute structure. The atomic populations determined in the A and B positions were 1.834 K + 0.166 □ and 5.705 Na + 0.198 K + 0.031 Ca + 0.034 Mg, respectively, implying the substitution of K for Na in the B position. The a and c dimensions are a = 10.0270(3) and c = 8.4027(3) Å. The average < A –O> and < B –O> distances are 3.009 and 2.65 Å, respectively. The substitution of K for Na in the B channel results in increased volume and bond-length distortion of the B O8 polyhedra, which then reduces distortion of the A O9 polyhedra. The average T –O distances indicate that the T 1 and T 4 sites are essentially filled with Al, whereas the T 2 and T 3 are filled with Si. Despite the deviation of the O1 oxygen from the triad axis and the combination of K+ ions and vacancies in the hexagonal channels, an incommensurate structure was not observed in the X-ray diffraction data or using the electron diffraction technique. [ABSTRACT FROM AUTHOR]

Peripheral arterial disease (PAD) is associated with coronary artery disease (CAD) and stroke, but data on the relationship between PAD and acute ischemic stroke are lacking. Therefore, we investigated this relationship. A total of 101 patients were enrolled on admission to Harasanshin General Hospital (Fukuoka, Japan) with their first ischemic stroke. All 101 patients underwent cranial CT and/or brain magnetic resonance imaging, duplex ultrasonography of the extracranial carotid arteries, and transthoracic echocardiography. The subjects were aged 41 to 92 years. PAD was present in 81/101 patients (80.2%), including 57/73 (78.1%) with small artery occlusion, 11/13 (84.6%) with large artery occlusion, and 13/15 (86.7%) with cardiogenic embolism. In 42 of these 81 patients (51.9%), PAD was asymptomatic. Serum apoprotein A1 levels were significantly higher and the intima-media thickness was significantly greater in the patients with PAD than in those without PAD. The modified Rankin scale score was significantly higher on admission in patients with PAD than in those without PAD. Stepwise logistic regression analysis revealed that the apoprotein A1 level and the modified Rankin scale score on admission were strongly associated with the occurrence of stroke in patients with PAD. Our results suggest that PAD is frequently associated with acute ischemic stroke. It may be important to perform screening for PAD in patients who have suffered an ischemic stroke.