(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.
Crystalline
Definition:
(a.) Consisting, or made, of crystal.
(a.) Formed by crystallization; like crystal in texture.
(a.) Imperfectly crystallized; as, granite is only crystalline, while quartz crystal is perfectly crystallized.
(1) In addition to the phase diagrams reported here for these two binary mixtures, a brief theoretical discussion is given of other possible phase diagrams that may be appropriate to other lipid mixtures with particular consideration given to the problem of crystalline phases of different structures and the possible occurrence of second-order phase transitions in these mixtures.
(2) In 0.17 M Na+(aq), tRNA(Phe) exists in its native conformation and the number of strong binding sites (Ka greater than or equal to 10(4)) was estimated to be 3-4 by titration experiments, in agreement with X-ray structural data for crystalline tRNA(Phe) (Jack et al., 1977).
(3) Electron microscopy revealed the presence of a hitherto unreported peculiar "pilovacuolar" inclusion in numerous mitochondria, composed of an electron dense pile or rod within a vacuole, while globular or crystalline inclusions were absent.
(4) The advantages of the incision through the pars plana ciliaris are (1) easier approach to the vitreous cavity, (2) preservation of the crystalline lens and an intact iris, and (3) circumvention of the corneal and chamber angle complications sometimes associated with the transcorneal approach.
(5) These two crystallins were compared with respect to their native molecular masses, subunit structures, peptide mapping and amino acid compositions in order to establish the identity of each crystallin.
(6) Freeze-dried mannitol preparations were shown to be of a crystalline nature.
(7) Antigenic properties of crystalline pepsin, trypsin and chymotrypsin were studied in 9 rabbits immunised with these enzymes.
(8) X-ray diffraction spectrum of 1:8 coprecipitate (COPPT) showed no crystalline structure of AD.
(9) However, significant differences in the formation and melting of the highly crystalline phase were evident between the two polar headgroup stereoisomers.
(10) Degradation studies of the crystalline antibiotic, m.p.
(11) Crystalline derivatives of the amino sugar i. e. methyleremosaminide and methyl-N,O-acetyleremosaminide (alpha- and beta-anomers) were prepared.
(12) A systematic structural comparison of several carp gamma-crystallins with high methionine contents was made by the secondary-structure prediction together with computer model-building based on the established X-ray structure of calf gamma-II crystallin.
(13) The lens cell-free system synthesizes in addition to the crystallins, polypeptides which co-electrophorese with lens plasma membrane protein components.
(14) Arrhenius plots of the leakage rates showed breaks in the 20-25 degrees C temperature range, which correspond to the gel-liquid crystalline phase transition of the target liposomes.
(15) These results suggest that ATP modulates the functional behavior of alpha-crystallin.
(16) Because anesthetics transform the solid-gel membrane into a liquid-crystalline state, and because phospholipid membranes display an anomaly in permeability at the phase transition, dimyristoylphosphatidylcholine vesicles were studied at temperatures above the main phase transition to avoid this anomaly.
(17) By monitoring the synthesis of specific lens crystallin proteins, and the morphological and cellular changes associated with this differentiated system, we have demonstrated a close correlation between statin expression and cell commitment to the G0 nonreplicative cell cycle state.
(18) Developmental regulation of crystallin protein synthesis was observed in rat lenses between embryonic day 19 and postnatal day 21.
(19) Bovine lens calf gamma-II crystallin contains five histidine residues at sequence positions 14, 53, 84, 117, and 122.
(20) A second crystalline material was observed within cells in the 15,000 X g pellet from spinal fluid.