No abstract

The process of palate fusion was examined in 13- and 14-day-old mouse fetuses by using in situ staining for nuclear DNA fragmentation (TUNEL method) and immunofluorescent staining for keratin, with special reference to the disruption of the midline epithelial seam. TUNEL-positive cells were found in the disappearing midline seam and the oral and nasal epithelial triangles at some late stages of palate fusion, but not in the palatal shelves prior to contact or in the intact midline epithelial seam. It seems that DNA fragmentation or apoptosis is required for the midline epithelial seam to disrupt, but may not be necessary for initial contact of palatal shelves or for the epithelial fusion of opposing palatal shelves. A similar sign of apoptotic cell death was observed in the disappearing epithelial seam between the fusing nasal septum and dorsal palate. We have demonstrated that apoptotic programmed cell death does occur at some stages of palate fusion, although the present results do not exclude the possibility of epithelial-mesenchymal transformation and the oral and nasal migration of midline epithelial cells.

Based on a fourth generation single crystal (SC) superalloy, TMS-138, we designed new SC alloys that contain higher amount of refractory elements, Nb, Ta, Mo, or Re, for strengthening. The Ru content was also increased to improve the phase stability. The creep strength and microstructure of these alloys were examined and compared with those of the base alloy TMS-138 and a third generation SC superalloy, CMSX-10K. As predicted by our alloy design program, TMS-162 (Mo and Ru addition) and TMS-173 (Re and Ru addition) exhibited excellent creep properties. Their times to 1% creep deformation at 1100 C/137MPa were about 2.5 times as long as that of TMS-138 and 5 times as long as that of CMSX-10K. The temperature capability of TMS-162 has reached a project target of 1100 C under stress at 137MPa and a creep rupture life as long as 1000 h, which is the highest ever reported.

No abstract

We report 2 cases of Legionella pneumonia in individuals who were exposed to aerosols during maintenance of a cooling tower at a waste processing plant. This report documents the first known occupation-related outbreak of Legionella pneumonia in Japan.