Hydroxyapatite (HAp) is widely used as bioceramics for bone and dental tissue reconstructions due to its excellent biocompatibility with hard tissues and high osteoconductivity. Although it is well known that HAp has the high adsorbed ability, its ability is decreased in high ionic solution. To immobilize protein on the HAp surface, this study demonstrates that Collagen (Col) and fibronectin (Fnt) were immobilized on the surface of hydroxyapatite (HAp) sintered body with and without the silane coupling agent of aminopropyltriethoxysilane (APS). The proteins immobilized on the HAp and APS/HAp surfaces were investigated by atomic force microprobe (AFM, Simadzu; SPM 9500) analyses and Ζ potential measurements. The stability of protein/APS/HAp and protein/HAp composites was evaluated after immersion in phosphate buffer and NaCl solutions with various concentrations. AFM analyses and Ζ potential measurements revealed that proteins immobilized on the APS/HAp are more stable than those immobilized on the HAp in high ionic solutions.

This study aimed to assess the visuospatial abilities of five children with Williams syndrome (four males aged 9 years 3 months, 7 years 11 months, 8 years 1 month, and 10 years 8 months respectively, and one female aged 6 years 3 months). First, the children's visuospatial abilities were examined by asking them to copy a figure. Second, their cognitive processing abilities were assessed using the Japanese Kaufman Assessment Battery for Children. This test was used because it is an objective one, standardized in Japan, and is a measure of fluid ability including spatial localization. Participants scored significantly low on the spatial memory subtest indicating that there was a deficit in spatial localization. Children's performance in line copying tasks improved when the dots were in colour. Results suggest a deficit in the dorsal stream of visual cognition, with a relatively preserved ventral stream.