The calcium phosphate composite octacalcium / calcite was obtained at pH 5–7 from the CaCO 3 /Ca(H 2 PO 4 ) aqueous suspension in a galvanostatic mode current density of 20 mA/cm for min. Drying 80 °C without precipitate maturation stage led to powder formation consisting brushite, and small amount phosphate. Prolonged air months hydrolytic transformation brushite into stabilized by calcite. us...

The aim of the present study was to evaluate the effects of experimental saliva substitutes based on carboxymethyl cellulose (CMC) differing in degrees of saturation with respect to calcium phosphates on the mineral loss of enamel in vitro. Demineralized bovine specimens (subsurface lesions) were exposed to one of six experimental CMC-based solutions with theoretical degrees of saturation with ...

Hydroxyapatite (HAp) is a major component of bones and teeth. HAp widely used to repair, fill, extend, reconstruct damaged bone tissue. for dental implants, so it necessary synthesize HAp. synthesis can utilize green mussel shell waste as calcium precursor. This research synthesized from using the sol-gel method. The controlled parameter was pH, variable being compared heating temperature at 90...

In chemistry of inorganic crystals, the octacalcium phosphate (OCP) is an apatite based crystals and having a hydrated layers which used in producing needle or plate-shaped hydroxyapatite (HAP) nanocrystals. Although, prepared by dissolution precipitation reaction. These reaction led to hexagonal HAP nanocrystals formation under hydrothermal condition from OCP at 180 for 3 hours with pH solutio...

T paper develops algorithms for finding Coxian generators to phase-type (PH)-majorize a PH-generator T with only real eigenvalues. In the first part of this paper, we investigate matrices S and P satisfying TP = PS and Pe= e. Conditions on T are identified for S to be an ordered Coxian generator and for P to be nonnegative, which consequently implies that S PH-majorizes T . It is shown that eve...

Dissolution of the (100) face of octacalcium phosphate (OCP) single crystal in weak acidic solutions (pH = 6.5; 25 ̊C) was observed in situ using atomic force microscopy. Monomolecular steps (2.0 nm high) were observed; they originated from etch pits or crystal edges. Advancement of the dissolution process led to precipitation of nanoparticles as small as ~10 nm even though the solution was unde...

The spherical porous granules of octacalcium phosphate (OCP) and hydroxyapatite (HA) have the potential for applications in scaffolds bone regeneration. alpha-tricalcium were immersed a pH 5.0 buffer solution that contained 0.1 mM ascorbic acid (AscP), an osteogenesis-promoting drug, at 60 °C. This resulted fabrication AscP-loaded HA/OCP granules. OCP HA phases concentrated surface interior gra...

Calcium phosphate is attracting attention as a bone repair material and controlled-release carrier of various drugs such disease therapeutic agents anticancer agents. Compared with some bioabsorbable polymers, calcium phosphates have the advantage preventing pH decrease in surrounding body fluid. However, there are few studies comparing effect supporting substances different physicochemical pro...

The strategy in biomineralization of initially depositing a less ordered mineral and then transforming it into a more crystalline mature phase is probably widespread among invertebrates. The report in this issue by N.J. Crane, V. Popescu, M.D. Morris, P. Steenhuis, M.A. Ignelzi, Raman spectroscopic evidence for octacalcium phosphate and other mineral species deposited during intramembraneous mi...

Diel pH changes in lake waters resulting from high photosynthetic activity may regulate water-soluble P concentration (WSP) and P sorption by suspended sediments in shallow eutrophic lakes. Laboratory studies were conducted to determine the pH effect on P fractions and P sorption kinetics in oxidized sediment suspensions from two subtropical lakes (Lake Apopka and Lake Okeechobee, Florida). The...