In the spinel titanate MgTi 2 O 4 , the tetragonal phase collapses upon substitution of a tiny amount of Mg ions at the Ti site, and the cubic phase with the geometrical frustration is resurrected. The atomic pair distribution function (PDF) and the extended x-ray absorption fine structure (EXAFS) reveal the nanoscale structural fluctuation, in which the Ti atomic displacement has the two-in two-out configuration in the cubic phase. We argue that the geometrical frustration plays an essential role in the collapse of the tetragonal phase and the resultant nanoscale ice-type structural fluctuation.

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Expression of ABH, Lewis, and sialyl Lea antigens was studied in five combined hepatocellular-cholangiocarcinomas. Formalin-fixed liver tissues were immunostained for those antigens using well-characterized monoclonal antibodies and an avidin-biotin-peroxidase complex (ABC) method. Results were compared with those obtained in normal liver tissues and cholangiocarcinomas, and also with the previous observations of the authors on hepatocellular carcinomas. Although not detected in normal parenchymal liver cells, A, H, Lewis, and sialyl Lea antigens were found in combined hepatocellular-cholangiocarcinoma cells. Incompatible A antigen also was detected in one blood type O patient. Distribution and intensity of the antigens were similar to those in hepatocellular carcinomas and different from those in cholangiocarcinomas. No preferential accumulation of blood-group antigens could be found in the area of cholangiocarcinoma-like differentiation of the combined hepatocellular-cholangiocarcinoma. The observations suggested that Regional morphological differentiation of the hepatocellular-cholangiocarcinoma might not be always associated with the change in the expression of the blood group antigens. Moreover, the expression was essentially the same between the hepatocellular-cholangiocarcinoma and the typical hepatocellular carcinoma. The hepatocellular-cholangiocarcinoma, therefore could be a variant of the hepatocellular carcinoma.

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Molecular hybridization methods for determination of hepatitis B virus DNA (HBV-DNA) in serum were studied. A simple method by which serum was treated with sodium hydroxide, followed by dot hybridization procedure on filter sheets provides a sensitive and direct result for detecting HBV-DNA. Another method in which DNAs extracted from Dane particle fraction were subjected to the molecular hybridization method on a filter membrane, provided similar results although this method is time consuming. The third method in which serum was directly spotted on filter sheets, followed by alkaline-treatment seems to be less sensitive. Three filter papers, NC filter, Zeta-Probe and Biodyne, on which molecular hybridization was performed, gave similar sensitivity.