CONTEXT The effect of calcium carbonate on the absorption of levothyroxine has not been studied systematically. Such a potential drug interaction merits investigation because concurrent treatment with both drugs is common, particularly in postmenopausal women. OBJECTIVE To investigate the potential interference of calcium carbonate in the absorption of levothyroxine. DESIGN Prospective coho...

introduction individual x-ray diffraction patterns of biological tissues are obtained via interference of coherent scattering with their electrons. many scientists have distinguished normal and cancerous breast tissue, bone density, and urinary stone types using the x-ray diffraction patterns resulting from coherent scattering. the goal of this study was to introduce an optimized method for obt...

Patients with chronic kidney disease (CKD) are given calcium carbonate to bind dietary phosphorus, reduce phosphorus retention, and prevent negative calcium balance; however, data are limited on calcium and phosphorus balance during CKD to support this. Here, we studied eight patients with stage 3 or 4 CKD (mean estimated glomerular filtration rate 36 ml/min) who received a controlled diet with...

in this study argillic horizons in calcareous soils of a semiarid region, with xeric and mesic soil moisture and temperature regimes, in the west of urmia lake were studied. thus, a toposequence in different physiographic positions including piedmont plains, plateau, hills and mountains was investigated. in each land type, three soil profiles were dug and described and their morphological prope...

Although the polymorphism of calcium carbonate is well known, and its polymorphs--calcite, aragonite, and vaterite--have been highly studied in the context of biomineralization, polyamorphism is a much more recently discovered phenomenon, and the existence of more than one amorphous phase of calcium carbonate in biominerals has only very recently been understood. Here we summarize what is known...

Calcium carbonate nano particles were synthesized using precipitation method from cockle shells by employing chitosan as precursor. Synthesized Calcium carbonates were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), UV-Visible and FTIR Spectroscopy. The results were compared with commercial calcium carbonate nano particles. Cockle shells are the potential source...

In this study, calcium carbonate crystals were obtained by mixing of calcium chloride and sodium carbonate in the presence of biopolymer, carboxymethyl inulin (CMI). The effect of the feed rate of reactant and the initial [Ca] concentration was investigated. The produced calcium carbonate (CaCO3) crystals were characterized by scanning electron microscopy (SEM), Fourier transform infrared spect...

BACKGROUND Calcium-based and non-calcium-based phosphate binders have similar efficacy in the treatment of hyperphosphatemia; however, calcium-based binders may be associated with hypercalcemia, vascular calcification, and adynamic bone disease. SCOPE A post hoc analysis was carried out of data from a 16-week, Phase IV study of patients with end-stage renal disease (ESRD) who switched to lant...

We compared the effectiveness of calcium acetate as a phosphate binder with that of calcium carbonate by substituting one for the other in patients undergoing continuous ambulatory peritoneal dialysis. Twenty patients who had been receiving calcium carbonate as a phosphate binder were instead given calcium acetate, initially with two thirds of the previous dose of elemental calcium. The calcium...

Calcium carbonate forms scales, geological deposits, biominerals, and ocean sediments. Huge amounts of carbon dioxide are retained as carbonate ions, and calcium ions represent a major contribution to water hardness. Despite its relevance, little is known about the precipitation mechanism of calcium carbonate, and specified complex crystal structures challenge the classical view on nucleation c...