Phase equilibria among η-Fe2Al5 and its higher-ordered phases.

Phase equilibria among the η-Fe2Al5 phase and its higher-ordered phases with the η framework structure were determined experimentally. The solubility range of the η phase at elevated temperature does not differ remarkably from that in previous studies, but this phase is found to undergo complicated phase transformations upon cooling. Four phases are present, namely η', η", η"' and η m, with higher-order atomic orderings in the c-axis chain sites of the orthorhombic crystal structure of the parent η phase. The η" and η"' phases form on the Al-poor and Al-rich sides, respectively, in equilibrium with the ζ-FeAl2 phase below ~415°C and θ-Fe4Al13 phase below ~405°C. The η' and η m phases become stable below 312°C and 343°C with the peritectoid reactions η' → η m + Î·"' and η m → η + Î·", respectively. The η phase is not stable below 331°C with the eutectoid reaction of η m + Î·"' → η. On the basis of these findings, we unraveled the phase equilibria among the η-Fe2Al5 phase and its higher-ordered phases with the η framework structure.

Crystal structure of η″-Fe3Al7+x determined by single-crystal synchrotron X-ray diffraction combined with scanning transmission electron microscopy.

The crystal structure of η″-Fe3Al7+x , the low-temperature phase of η-Fe2Al5 with a composition on the Fe-rich side of the solid solubility range, has been determined by synchrotron X-ray single-crystal diffraction combined with scanning transmission electron microscopy. The η″ phase possesses commensurate long-period-ordered superlattice structures (space group Pmcn) based on the parent orthorhombic unit cell of η-Fe2Al5, consisting of twin domains (orientation variants) alternately stacked along the long-periodicity axis. Each of the twin domains possesses a motif structure belonging to the base-centered monoclinic space group C2/m, with a cell volume twice that of the parent orthorhombic unit cell (space group Cmcm). One-fourth of the c-axis chain sites corresponding to Al2- and Al3-sites in the η phase are respectively occupied by both Fe and Al atoms and exclusively by Al atoms in a regular manner. This regularity is disturbed in the twin-boundary region, giving rise to structural/compositional modulation. Because of the different chemical compositions between the motif structure and twin-boundary region, the η″ phase with various compositions can be constructed only by changing the number of the parent orthorhombic unit cells to be stacked along the orthorhombic c-axis, without changing the atomic arrangements for the motif structure or the twin boundary to account for the observed solid solubility range. The chemical formula of the η″ phase can thus be expressed as Fe3Al7+x under a simple assumption on the occupancies for Al/Fe atoms in the c-axis chain sites.

Huge right ventricular mass lesion associated with genital malignant tumor: a case report.

BACKGROUND: Primary heart tumors are rare, whereas metastatic heart tumors occur more frequently. CASE PRESENTATION: We report a case of a 75-year-old Japanese woman who had metastatic heart tumors of the right ventricle. Although she initially received antibiotic therapy following a diagnosis of pneumonia and pleuritis, her symptoms worsened, and she developed dyspnea and bilateral lower limb edema. Echocardiography showed a huge mass lesion occupying the entire right ventricle. Because the patient's tumor markers were elevated, we used computed tomography to search for the primary lesion, which was located in the vagina or the uterus. Histology demonstrated the presence of basaloid squamous cell carcinoma in the vaginal tissue. Chemotherapy with paclitaxel and carboplatin was initiated. CONCLUSIONS: These data suggest that the tumor in the right ventricle metastasized from the genital organs.

Sinus dysfunction after stent implantation in the right coronary artery immediately recovered after reflow in the sinus node artery.

A 67-year-old man who had a history of syncope was admitted because of effort angina. The sinus node (SN) was the single blood supply from the right coronary artery (RCA). After we implanted 2 everolimus-eluting stents for RCA, slow-flow occurred and the SN artery was occluded, and junctional escape rhythm was sustained. After the wiring to the occluded SN artery, junctional escape rhythm immediately recovered to sinus rhythm, and the patient achieved continuous sinus rhythm and stable hemodynamics. Given that acute SN ischemia is a possible cause of sinus dysfunction, careful choice of a percutaneous coronary intervention strategy should be taken into consideration if the SN artery is the single blood supply from the RCA and if syncopal history is present.