The effects of niobium ions released from 60CaO-30P(2)O(5)-(10-x)Na(2)O-xNb(2)O(5) (mol %, x = 0-10) glasses on MC3T3-E1 cell functions were evaluated by culture tests with two systems; cell culture on glass plates, or in culture media containing glass extracts. Alkaline phosphatase (ALP) activity in the cells cultured on the glass plates containing 3 and 5 mol % of Nb(2)O(5) was significantly higher than that on the Nb(2)O(5)-free glass, although proliferation was not enhanced on all glasses containing Nb(2)O(5). Cells cultured in the medium containing 3 × 10(-7) M niobium ions showed the highest ALP activity in comparison with other Nb-containing media or normal medium, regardless of the presence of osteogenic factors (ascorbic acid, β-glycerophosphate and dexamethasone) in the media. Calcium deposition by the cells cultured in the medium containing 3 × 10(-7) M niobium ions was twice as high as those cultured in medium containing no niobium ions. The effects of niobium ions were thought to depend on ion concentration, and to enhance differentiation and mineralization of osteogenic cells rather than their initial adhesion or proliferation.

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Superconducting joints have been demanded to lengthen REBa 2 Cu 3 O y -coated conductors for electrical power applications. In this study, we propose a new joint method for GdBa 2 Cu 3 O y -coated conductors via crystallizing precursor films additionally deposited on the conductors. Two GdBa 2 Cu 3 O y -coated conductors with precursor films were placed in a face-to-face manner in a furnace, then they were crystallized under mechanical pressure to joint them. A superconducting joint was achieved with a high critical temperature of 90.8 K. Microstructural observation by a transmission electron microscope revealed that there were only a few pores at the joint boundary without a secondary phase having c-axisoriented GdBa 2 Cu 3 O y .

New types of calcium phosphate glass-ceramics were prepared with the addition of Nb 2 O 5 to the pyrophosphate region. The glassceramics contained ¡-Ca 2 P 2 O 7 , ¢-Ca 2 P 2 O 7 , and orthorhombic Nb 2 O 5 . The concentrations of Ca, P and Nb elements released from the glass-ceramics were lower than those released from glass of the same chemical composition. Apatite formed on the surface of the glass-ceramics after soaking in 1.5 simulated body fluid for 7 days. The crystal phases of the glass-ceramics improved the chemical durability and apatite forming ability of the material.