17/06/13 meb. Open access paper, OK to pub

Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) nanocomplexes have been shown to prevent demineralization and promote remineralization of enamel subsurface lesions in animal and in situ caries models. The aim of this study was to determine the effect of incorporating CPP-ACP into a self-cured glass-ionomer cement (GIC). Incorporation of 1.56% w/w CPP-ACP into the GIC significantly increased microtensile bond strength (33%) and compressive strength (23%) and significantly enhanced the release of calcium, phosphate, and fluoride ions at neutral and acidic pH. MALDI mass spectrometry also showed casein phosphopeptides from the CPP-ACP nanocomplexes to be released. The release of CPP-ACP and fluoride from the CPP-ACP-containing GIC was associated with enhanced protection of the adjacent dentin during acid challenge in vitro.

We present the free surface response of 2, 5, and 8 m aluminum films to shocks generated from chirped ultrafast lasers. We find two distinct steps to the measured free surface velocity that indicate a separation of the faster elastic wave from the slower plastic wave. We resolve the separation of the two waves to times as short as 20 ps. We measured peak elastic free surface velocities as high as 1.4 km/s corresponding to elastic stresses of 12 GPa. The elastic waves rapidly decay with increasing sample thickness. The magnitude of both the elastic wave and the plastic wave and the temporal separation between them was strongly dependent on the incident laser drive energy.

Mixtures of flake-shaped nickel and spherical aluminum powders have been subjected to shock-loading up to 6 GPa to investigate the occurrence of shock-induced chemical reactions. The high-pressure Hugoniot state is determined through time-resolved measurements of the input stress and shock transit time through the specimen. An increase in shock velocity is observed above stress levels of 3.5 GPa, suggesting the initiation of an ultrafast shock-induced chemical reaction and formation of Ni-Al compound͑s͒ occurring in the time scale of the high-pressure shock state.