The experimental results were quantitatively compared with the theory based on a physical model representing the reaction and with the experiments involving synthetic hydroxyapatite discs. The experimental initial rates self-consistently compared well with the theoretical predictions. An analysis of the experimental initial rate data yielded a reaction constant, ti. for the reaction representin...

Carbon (C), nitrogen (N), and phosphorus (P) stoichiometry their allometric relationships in soil plants are hot topics that attract a lot of attention, while those rocks form soils often neglected. Weathering is common geological phenomenon may significantly influence the nutrient composition release nutrients from rock its inherent soils. This study presents C, N, P concentrations data as wel...

B iomineralized materials are highly organized composites with hierarchical structures, in which the basic building blocks (apatite crystals) are generally in the nanometer size range to ensure optimum physical and biological functions (1). The biological mechanisms of tissue development have attracted a great deal of recent attention in fields ranging from biology and chemistry to materials sc...

Introduction: The calcium phosphate ceramics, in particular hydroxyapatite ( HA), has shown to be capable of conducting bone formation and forming a chemical bond to bone. Because of this osteoconductivity, HA ceramic has been applied in joint reconstruction in the form of coating on joint implants such as hip stems by plasma spraying technique. Direct bone apposition has been repeatedly demons...

Powder mixtures with a given molar ratio of Ca/P = 1.67 were prepared under mechanical activation conditions from hydroxyapatite powder Ca10(PO4)6(OH)2 and 1M aqueous solution oxalic acid H2C2O4 at Ca10(PO4)6(OH)2/H2C2O4 1:4. The phase composition obtained mixture included brushite (calcium hydrophosphate dihydrate) CaHPO4·2H2O, calcium oxalate monohydrate CaC2O4·H2O in form whewellite weddelli...

The western side of Hong Kong possesses estuarine characteristics (from the Pearl River estuary) and the eastern side is mainly influenced by the oligotrophic South China Sea, while the southern side has intermediate hydrological characteristics. We investigated the concentrations of dissolved inorganic nutrients and limitations to phytoplankton growth at these 3 locations around Hong Kong. As ...

introduction: this study aimed to compare the cytotoxicity of mta fillapex, ah-26 and apatite root canal sealers at different times after mixing. methods and materials: in this in vitro study, mta fillapex, ah-26 and apatite root canal sealer were spilled uniformly by 40 µm mesh in a 96-well plate. then, human fetal foreskin fibroblast cell line (hfff2) were added to each sealer cell culture me...