ABSTRACT
Fabricating large, high-crystalline-quality single-crystal samples of hexagonal ferrite Ba(Fe1-x Sc x )12O19 is the first important step to elucidating its helimagnetic structure and developing it for further applications. In this study, single crystals of Ba(Fe1-x Sc x )12O19 of various Sc concentrations x were successfully grown by the spontaneous crystallization method using Na2O-Fe2O3 flux. We determined the optimal starting composition of reagents for Ba(Fe1-x Sc x )12O19 growth as a function of x. In situ monitoring of the crystal nucleus generation accelerated the success of crystal growth. The obtained crystals comprised black and lamellate structures with a size of 13 mm × 8 mm × 2 mm and a surface of {001} orientation. X-ray diffraction and elemental analysis revealed that the obtained crystals were composed of single-phase Ba(Fe1-x Sc x )12O19 of high crystalline quality. The lattice constants a and c increased linearly with increasing x, thereby following Vegard's law. The temperature dependence of magnetization and the magnetization curves at 77 K of the x = 0.128 crystal exhibited behavior characteristics of helimagnetism. Neutron diffraction measurements of the x = 0.128 crystal exhibited magnetic satellite reflection peaks below 211 K, providing evidence that Ba(Fe1-x Sc x )12O19 behaves as a helimagnetic material.
ABSTRACT
PURPOSE: We have fabricated, for clinical application, artificial oral mucosa that totally excludes both heterogenic protein interaction and xenotransplantation. The purpose of this study is to compare the fatty acid composition of cell membrane phospholipids related to post-transplantation epithelial regeneration. MATERIALS AND METHODS: Cultured keratinocytes, keratinocytes at 2, 3, 4, and 9 weeks after transplantation, and normal oral keratinocytes were compared by gas chromatography for the composition of 23 fatty acids. The relation between the composition of cell membrane fatty acids, and the glucose metabolism was immunohistochemically analyzed. RESULTS: 1. Even after transplantation, cultured keratinocytes retained the same ratio of palmitic acid as that of normal oral keratinocytes. 2. Essential fatty acids decreased markedly in cultured keratinocyte membranes to the same composition as that of normal oral mucosa 2 weeks after transplantation. 3. The percent composition of palmitoleic acid in cultured keratinocytes was significantly higher than that in post-transplanted keratinocytes; it decreased 2 weeks after artificial mucosa transplantation, but became similar to that in 3 weeks thereafter. 4. The entire population of stratified keratinocytes in EVPOME before transplantation expressed GLUT-1 protein. CONCLUSION: Our findings suggest that post-artificial mucosa epithelialisation allows keratinocytes to proliferate while consuming palmitic acid, and then diet-provided essential fatty acids induce the keratinocytes to differentiate. Complete clinical epithelialisation of the transplant wound requires 4 weeks; however, within 3 weeks of transplantation, cultured cells of a specific metabolic mechanism change into or are replaced by keratinocytes of a normal metabolic mechanism similar to that of surrounding tissue.
