Sparingly dissoluble calcium salts were studied as reactants in the synthesis of needlelike precipitated calcium carbonate (PCC). Morphology and aspect ratio of the PCC particle were characterized with SEM. Polymorphs and crystal size were characterized using x-ray diffraction. The counter-ions of the sparingly dissoluble salts influenced growth kinetics of PCC as well as the polymorphs and mor...

Global databases of calcium carbonate concentrations and mass accumulation rates in Holocene and last glacial maximum sediments were used to estimate the deep-sea sedimentary calcium carbonate burial rate during these two time intervals. Sparse calcite mass accumulation rate data were extrapolated across regions of varying calcium carbonate concentration using a gridded map of calcium carbonate...

Background: Hyperphosphatemia remains a common problem in patients on maintenance dialysis and contributes to the development of secondary hyperparathyroidism. Current therapies for the treatment of hyperphosphatemia are frequently insufficient to achieve the recommended K/DOQI goal of maintaining serum phosphorus level between 3.5 and 5.5 mg/dl. Niacinamide inhibits intestinal sodium/ phosphor...

BACKGROUND Calcium and vitamin D play an essential role in bone metabolism but deficiency and/or inadequate intake are common. OBJECTIVES To describe a practical approach based on the literature regarding clinically important aspects of calcium and vitamin D supplementation. METHODS A systematic evaluation of relevant literature in Medline was conducted. We included physiological studies, p...

Both K and Ca supplementation may have beneficial effects on bone through separate mechanisms. K in the form of citrate or bicarbonate affects bone by neutralising the acid load caused by a high protein intake or a low intake of alkalising foods, i.e. fruits and vegetables. Ca is known to decrease serum parathyroid hormone (S-PTH) concentration and bone resorption. We compared the effects of ca...

The stimulation of bacterial activities that convert hexavalent uranium, U(VI), to tetravalent uranium, U(IV), appears to be feasible for cost-effective remediation of contaminated aquifers. However, U(VI) reduction typically results in the precipitation of U(IV) particles less than 5 nanometers in diameter, except for environmental conditions enriched with iron. Because these tiny particles ar...

BACKGROUND Recent reports highlighting the role of particle geometry have suggested that anisotropy can affect the rate and the pathway of particle uptake by cells. Therefore, we investigate the internalization by cells of porous calcium carbonate particles with different shapes and anisotropies. RESULTS We report here on a new method of the synthesis of polyelectrolyte coated calcium carbona...

BACKGROUND Lanthanum carbonate (FOSRENOL(®), Shire Pharmaceuticals) is an effective non-calcium, non-resin phosphate binder for the treatment of hyperphosphataemia in patients with chronic kidney disease (CKD). In this study, we used a rat model of chronic renal failure (CRF) to examine the long-term effects of controlling serum phosphorus with lanthanum carbonate treatment on the biochemical a...

The Eocene-Oligocene transition (EOT), ~34Ma, marks a tipping point in the long-term Cenozoic greenhouse to icehouse climate transition. Paleorecords reveal stepwise rapid cooling and ice growth across the EOT tightly coupled to a transient benthic δC excursion and a major and permanent deepening of the carbonate compensation depth (CCD). Based on biogeochemical box modeling, Merico et al. (200...