Inorganic carbonate in soil occurs predominantly as the sparingly soluble alkaline-earth carbonates, calcite (CaCOs) and dolomite (CaMg(CO,),). Calcite is usually the dominant form in active pedogenic environments (Doner & Lynn, 1977; Nelson, 1982). There are only a few reported occurrences of aragonite (CaCOs) and vaterite (CaCOs) in soils. Sodium carbonate and magnesium carbonate and hydroxyc...

A new diagnostic concept based on deep Raman spectroscopy is proposed permitting the non-invasive determination of the level of carbonate substitution in type II calcifications (HAP). The carbonate substitution has shown to be directly associated with the pathology of the surrounding breast tissue and different pathology groups can therefore be separated using specific features in the Raman spe...

BACKGROUND There are not many studies evaluating the effects of surface treatments at the molecular level. The aim of this in vitro study was to analyze the concentration of carbonate molecules in dental enamel by Raman spectroscopy after the application of in-office and home whitening agents. MATERIAL AND METHODS Sixty human teeth were randomly divided into six groups and exposed to three di...

Laboratory column tests conducted to gain insight regarding the biological and chemical clogging mechanisms in a porous medium are presented. To seed the porous medium with landfill bacteria, a mixture of Keele Valley Landfill and synthetic leachate permeated through the column under anaerobic conditions for the first 9 days of operation. After this, 100% synthetic leachate was used. The synthe...

Carbonated hydroxylapatite (C-OHAp) and carbonate apatite (CAp; x 0.5) in the composition series Ca10(PO4)6–y[(CO3)x+(3/2)y(OH)2–2x], x = 0.0–0.7, y = 0.0–0.6, have been synthesized at 2–4 GPa, and studied by FTIR spectroscopy and single-crystal X-ray diffraction. Three structural locations for the carbonate ion have been identifi ed: (1) apatite channel, oriented with two oxygen atoms close to...

Studies of the average crystal structure properties of human dental apatite as a function of age in the range of 5-87 years are reported. The crystallinity of the dental hydroxyapatite decreases with the age. The a-lattice constant that is associated with the carbonate content in carbonate apatite decreases with age in a systematic way, whereas the c-lattice constant does not change significant...

Geochemical models for Mars predict carbonate formation during aqueous alteration. Carbonate-bearing rocks had not previously been detected on Mars' surface, but Mars Reconnaissance Orbiter mapping reveals a regional rock layer with near-infrared spectral characteristics that are consistent with the presence of magnesium carbonate in the Nili Fossae region. The carbonate is closely associated w...

This study was designed to determine the effects of an aluminum hydroxide antacid and a calcium carbonate antacid on the bioavailability of ciprofloxacin (Cipro). Cipro (750 mg) was administered orally to 12 healthy volunteers in a three-way randomized crossover design. The three treatments included Cipro alone, four 850-mg calcium carbonate tablets taken 5 min before Cipro, and three 600-mg al...

Aluminium- or calcium-based phosphate-binding agents traditionally have been used to treat hyperphosphataemia in patients with end-stage renal disease. Although these agents effectively lower serum phosphorus levels, they are associated with serious side effects. Aluminium-based agents are associated with bone toxicity, renal osteodystrophy and encephalopathy, and calcium-based agents increase ...