Bioactive glass-containing toothpastes for treating dentine hypersensitivity work by precipitating hydroxycarbonate apatite (HCA) onto the tooth surface, but concerns exist over the long-term durability of HCA in the mouth. Fluoride-containing bioactive glasses form fluorapatite (FAp) in physiological solutions, which is more chemically stable against acid attack. The influence of phosphate con...

Inorganic phosphate is determined by a molybdenummethodby using atomic absorption spectrophotometry, on the basis of the observations of Berenblum & Chain (1938) and Zaugg & Knox (1966, 1967). The method permits analysis for calcium in the same sample and can detect 0.1 ,ug of P. The procedure given below is designed for automatic diluters and dispensers and uses 0.2ml of plasma. It is suitable...

This paper estimates annual P emission to the Jaguaribe River estuary, NE Brazil, responsible for approximately 30% of the country's farmed shrimp production. Emissions increased three times between 2001 and 2006 and reached 43.9 t.year-1. These emissions make aquaculture the third main source of P for this estuary and are much smaller than emissions from agricultural sources and slightly lower...

Biomimetic coatings constituted of gelatin and nanocrystalline apatite were deposited on titanium substrates from a slightly supersaturated calcium phosphate (CaP) solution enriched with different amounts of gelatin. Although the biopolymer inhibits the crystallization of the inorganic phase, as shown by the reduction of the mean dimensions of the spherical aggregates and of the degree of cryst...

The sea urchin Lytechinus variegatus can survive chronic exposure to sodium phosphate (inorganic phosphate) concentrations as high as 3.2 mg L-1, and triethyl phosphate (organic phosphate) concentrations of 1000 mg L-1. However, chronic exposure to low (0.8 mg L-1 inorganic and 10 mg L-1 organic phosphate), medium (1.6 mg L-1 inorganic and 100 mg L-1 organic phosphate) or high (3.2 mg L-1 inorg...

The present study investigates the changes in microstructure and microchemistry (particularly Ca/P ratio) during whisker formation on the surface of TTCP powder in hydrochloric solution. XRD results indicate that the as-fabricated (non-treated) powder has a monolithic TTCP crystal structure. When the powder is treated for 10min in HCl, a DCPD phase appears on TTCP surface, which increases in in...

[1] The upper basin of Effingham Inlet possesses permanently anoxic bottom waters, with a water column redox transition zone typically occurring at least 40 m above the sediment-water interface. During our sampling campaign in April and July 2007, this redox transition zone was associated with sharp peaks in a variety of parameters, including soluble reactive phosphorus (SRP) and total particul...