(n.) Calcium carbonate, or carbonate of lime. It is rhombohedral in its crystallization, and thus distinguished from aragonite. It includes common limestone, chalk, and marble. Called also calc-spar and calcareous spar.
Example Sentences:
(1) The crystallographic orientation of the calcite also appears to be independent of these fibrils.
(2) The calcium carbonates-calcite, aragonite, and vaterite-constitute most of the remainder of the calculi.
(3) Crystallographic analysis of stones from patients with nutritional pancreatitis (NP), as well as alcoholic pancreatitis (AP), revealed that the main constituent was calcite (CaCO3).
(4) Calcite was present in all stones, vaterite in 12%, and a central amorphous material in 30%.
(5) X-ray diffraction showed that calcite (CaCO3) was the major crystalline constituent of the calcareous deposits.
(6) When the doped glasses have been immersed in a physiological solution (199 medium), a film of calcite forms on the glass surface and this modification is related to the type of doping agent used, decisive for close linking between metal supports and the glass.
(7) We suggest that precipitation of calcite in the pancreatic duct occurs as the primary event in the formation of pancreatic calculi and that it may continue until the duct is completely occluded.
(8) 5-7): calcite and quartz are the principal components of the sinters, additional diffuse apatite lines appear in bone samples.
(9) These features are characteristic of sea urchin (Echinoderm) spines which are composed of ornately formed calcite crystals covered by an epithelium.
(10) Its absence in all analyzed invertebrate tissues (including calcitic, aragonitic, and apatitic mineral phases) indicates that matrix protein-bound gamma-carboxyglutamic acid is not obligatory for the calcification process in the invertebrates.
(11) Quantitatively, phosphate is by far the most important inhibitor of calcite precipitation present in saliva, suggesting that inhibition of calcite precipitation by the macromolecules may be of secondary significance.
(12) Plates of calcite (CaCO3) were implanted in rabbit tibiae, and their biocompatibility and bonding ability to bone were studied.
(13) Subsequent increase in diameter of the rod involves the radial development of irregular columns of calcite which arise from the peripheral nodules.
(14) The phenomenon of dissolution and recrystallisation in situ of the calcite can be a trap because it can be a reservoir for micro-organisms.
(15) Synechococcus strain GL24 was isolated from Fayetteville Green Lake, New York, where it has a demonstrated role in the formation of calcitic minerals.
(16) Pancreatic stones are observed in both humans and cattle, and are approximately 95% CaCO3 (calcite) in both species.
(17) Skeletal walls of more than one mineralogy have the magnesium-rich layer (calcite) surrounding the living chamber and the strontium-rich layer (aragonite) on the outside.
(18) Here we report on the ability of a soil bacterium to synthesize calcite in a calcium-stressed environment.
(19) Formation of inner protein nidus in the form of a cobweb is the first stage, then calcite is deposited on this fibrous network as tiny crystals.
(20) The biocompatibility of mammal bone with aragonite and calcite skeletons of aquatic invertebrates (Corals, Molluscs) led us, after animal experimentation, to implant in humans artificial dental roots derived from such invertebrates.
Magnesite
Definition:
(n.) Native magnesium carbonate occurring in white compact or granular masses, and also in rhombohedral crystals.
Example Sentences:
(1) The issues related to dust are divided into two problem areas: a) dust aerosol arising in the process of ore mining and consisting largely of magnesite (MgCO3) and b) dust aerosol originating during ore baking in rotatory furnaces and made up mostly of MgO.
(2) In Experiment 2, urinary Mg excretion on d 4 and 5 of the collection was lower for sheep fed the brine oxide than for those fed sulfate or oxide from calcined magnesite.
(3) The characteristic features of chlorite, asbestos, magnesite, quartz and other minerals recognizable through these methods are described.
(4) Several animal species (domestic rabbits, Wistar rats, cattle) were used to biologically monitor the accumulation and effects of inhaled magnesite aerosol in two actual locations of the magnesite industry.
(5) Changes induced by magnesite dusts on the mucosa relief of the airways of rabbits are described.
(6) The present paper is an overview of the experimental research into the effects of flue magnesite dust in the magnesite industry in which the raw material (magnesite) is processed into refractory magnesite clinker.
(7) Experimental research carried out on laboratory animals after chamber exposure provided findings on the deposition, retention and elimination of magnesite dust, on impaired balance between magnesium and calcium leading to damage of biological membranes, on how the immune profile or reproduction and embryogenesis is impacted as well as on the possible interaction with sodium salicylate as a result of an impaired acid base balance.
(8) Experiments were performed to try to reproduce this effect of high magnesium (from added calcined magnesite) on the incidence of urolithiasis in lambs.
(9) In Experiments 1 and 2, absorption of Mg from the oxide of brine origin and larger particle size distribution was lower than that from sulfate, but there was no difference in absorption for sheep fed oxides derived from sea water or calcined magnesite.
(10) Magnesite waste containing largely magnesium oxide (MgO) and a mixture of other metals forms aerosols with a considerable portion of respirable particles when released into the atmosphere.
(11) Rats and rabbits were exposed through the respiratory system to industrial dusts (magnesite emissions, solid wastes from nickel refinery dump, cement emissions) at biomonitory stations or in experimental chamber.
(12) Three types of industrial emissions were investigated: magnesite emissions, wastes from nickel refinery and cement emissions, respectively.