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Lead lanthanum zirconate titanate (PLZT, (Pb,La)(Zr,-Ti)O3) ceramic fibers were prepared by the sol-gel method from a solution of lead acetate trihydrate, lanthanum isopropoxide, zirconium n-propoxide, and titanium isopropoxide that contained 2-methoxyethanol as the solvent. The sols obtained from the solution were concentrated at 156°-174°C for 2 h. Concentration at higher temperatures resulted in more-viscous sols of higher specific gravities. The concentration resulted in the formation of spinnable sols, which had viscosities >105mPas and exhibited Newtonian flow properties. These spinnable sols were formed to be so stable that no change in viscosity and spinnability was observed for more than three months when stored in a sealed container at room temperature. Gel-to-ceramic fiber conversion was investigated by means of X-ray diffractometry, infrared spectroscopy, and thermal analysis. Single-phase perovskite PLZT ceramic fibers 5-200 ?m in diameter and >20 cm in length were obtained. Scanning electron microscopy (SEM) observation and Brunauer-Emmett-Teller (BET) measurement showed that heat treatment of the fibers at a lower rate resulted in the formation of fibers of denser microstructure. Although the SEM image of the cross section of the fibers revealed a relatively dense microstructure and a laser beam could be transmitted through a fiber 6 mm in length, BET measurement of the fibers indicated that the fibers had more than a few percent of open porosities, and scattering of light was observed in the laser-beam guiding test.

The differences in the morphodifferentiation of subneural apparatuses (SNAs) at neuromuscular junctions (NMJs) in the extensor digitorum longus muscle of normal and dystrophic (mdx) mice were examined by scanning electron microscopy. In normal mice, primitive shallow cup-like synaptic troughs present at birth had developed to anastomosing grooves containing both pitlike and slit-like junctional folds (JFs) during the 2nd postnatal week. At the 35th day, the SNAs had developed to almost the adult forms, consisting of labyrinthine synaptic grooves with exclusively slit-like JFs. In the mdx mice, the SNAs showed transformation similar to those in the normal mice until the 35th postnatal day. After this period, SNAs with a number of cup-like depressions occurred and increased in number. These morphological changes seemed to be found on regenerating muscle fibers after necrosis, probably indicating the remodelling of their NMJs.