What's the difference between calcium and whewellite?
Calcium
Definition:
(n.) An elementary substance; a metal which combined with oxygen forms lime. It is of a pale yellow color, tenacious, and malleable. It is a member of the alkaline earth group of elements. Atomic weight 40. Symbol Ca.
Example Sentences:
(1) In studies of calcium metabolism in 13 unselected patients with untreated sarcoidosis all were normocalcaemic but five had hypercalcuria.
(2) After stimulation with lipopolysaccharide and calcium ionophore A23187, culture supernatants of clones c18A and c29A showed cytotoxic activity against human melanoma A375 Met-Mix and other cell lines which were resistant to the tumor necrosis factor, lymphotoxin and interleukin 1.
(3) The half-life of 45Ca in the various calcium fractions of both types of bone was 72 hours in both the control and malnourished groups except the calcium complex portion of the long bone of the control group, which was about 100 hours.
(4) Calcium alginate dressings have been used in the treatment of pressure ulcers and leg ulcers.
(5) of PLA2 caused marked degranulation of mast cells in the rat mesentery which was facilitated by addition of calcium ion (10 mM) but antagonized by pretreating with three antiinflammatory agents.
(6) Thus adrenaline, via pre- and post-junctional adrenoceptors, may contribute to enhanced vascular smooth muscle contraction, which most likely is sensitized by the elevated intracellular calcium concentration.
(7) It includes preincubation of diluted plasma with ellagic acid and phospholipids and a starting reagent that contains calcium and a chromogenic peptide substrate for thrombin, Tos-Gly-Pro-Arg-pNA.
(8) The results show that endolymph is extremely inhomogenous with respect to calcium potentials.
(9) The occupation of the high affinity calcium binding site by Ca(II) and Mn(II) does not influence the Cu(II) binding process, suggesting that there is no direct interaction between this site and the Cu(II) binding sites.
(10) This was unlike the action of the calcium channel blocker, cadmium, which reduced the calcium action potential and the a.h.p.
(11) Increases in extracellular calcium antagonized the negative inotropic effect.
(12) Plasma membranes were isolated from rat kidney and their transport properties for sodium, calcium, protons, phosphate, glucose, lactate, and phenylalanine were investigated.
(13) In experiments performed to determine whether PtdIns(4,5)P2 hydrolysis induced by TRH may have been caused by the elevation of [Ca2+]i, the following results were obtained: the effect of TRH to decrease the level of PtdIns(4,5)P2 was not reproduced by the calcium ionophore A23187 or by membrane depolarization with 50 mM K+; the calcium antagonist TMB-8 did not inhibit the TRH-induced decrease in PtdIns(4,5)P2; and, most importantly, inhibition by EGTA of the elevation of [Ca2+]i did not inhibit the TRH-induced decrease in PtdIns(4,5)P2.
(14) The distribution of gelsolin, a calcium-dependent actin-severing and capping protein, in the retina of the developing and adult rabbit was studied.
(15) In K+-depolarized basilar arteries, ifenprodil competitively antagonized the response to Ca2+, and this was enhanced by pre-incubation in calcium hopantenate.
(16) Thirty of the 32 women of the calcitonin group and 27 of 28 women of the calcium group finished treatment.
(17) The influence of calcium ions on the electrophoretic properties of phospholipid stabilized emulsions containing various quantities of the sodium salts of oleic acid (SO), phosphatidic acid (SPA), phosphatidylinositol (SPI), and phosphatidylserine (SPS) was examined.
(18) Hypercalcitoninemia was the most pronounced in patients with cardiac rhythm disorders and a simultaneous reduction in total serum calcium.
(19) The effects of low doses of dihydropyridine (DHP) calcium channel antagonists nimodipine, nifedipine, (-)-R-202-791, and amlodipine, the DHP calcium channel agonist BAY K 8644 were investigated on clonic convulsions to pentylenetetrazole (PTZ) in mice.
(20) A comprehensive review of the roentgenographic features of calcium pyrophosphate crystal deposition disease (pseudogout) is presented.
Whewellite
Definition:
(n.) Calcium oxalate, occurring in colorless or white monoclinic crystals.
Example Sentences:
(1) A large number of trace elements has been found in calcium stones (whewellite, weddellite, and apatite) and in struvite.
(2) These included diverse mono-, di- and trimineral stones, spontaneously excreted and surgically removed whewellite and weddellite calculi.
(3) The technique involves determining the surface elemental (hence chemical) composition of fractured whewellite stones.
(4) Calcium oxalate stones more often showed a whewellite texture (Type 2) and a less frequent occurrence of weddellite (Type 4) as compared to the control groups.
(5) The investigation of the degree of interpenetration between the two component phases of whewellite kidney stones, the protein matrix and calcium oxalate monohydrate crystallites, is extended by a technique of microchemical analysis, employing X-ray photoelectron spectroscopy (XPS).
(6) In solution a sequential series of phase transitions according to the steps calcium oxalate trihydrate-weddellite-whewellite is not likely to be energetically favoured; direct conversion of calcium oxalate trihydrate to whewellite should be, instead, ordinarily expected.
(7) SEM examination revealed structures similar to human stones such as bipyramidal weddellite, pseudomorphs from whewellite to weddellite, apatite deposits in cystine stones and characteristic mono-ammonium-urate needles.
(8) As transformation products are found fine-grained polycrystalline as well as due to recrystallisation larger monocrystalline whewellite.
(9) In patients with oxalate calculi the absorption of oxalic acid is totally increased and also in such ones with Whewellite-calculi.
(10) The prevalent types of calcium oxalate stones are: whewellite of concentric structure (linked with hyperuricemia) in Kirghizia; whewellite of small randomly orientated crystals (linked with hypercalciuria) and stones with signs of transformation of weddellite to whewellite in Moscow; (2) lesser distribution of phosphate lithiasis in Berlin than in Kirghizia and particularly in Moscow.
(11) Whewellite was the major component of calculi in all cases but the stones exhibited a peculiar morphological arrangement, with multiple small indentations and a fine mamillary structure.
(12) Tests were made, using both Vickers and Knoop indenters, on three compositions of calculi: 100% calcium oxalate monohydrate (whewellite), 100% uric acid, and 98% magnesium ammonium phosphate hexahydrate (struvite) mixed with 2% carbonate apatite.
(13) When the ratio of the weddellite content to the total of weddellite and whewellite (weddellite ratio) calculated using Oka's method on the infrared spectra was compared with that determined previously by TG, the correlation coefficient between these ratios was 0.734.
(14) In addition to tetragonal bipyramids, weddellite forms further crystal shapes that have been heretofore interpreted exclusively as whewellite crystals.
(15) It is formally demonstrated that along two axial directions a set of atoms is in essentially identical positions in both weddellite and whewellite.
(16) Whewellite may precipitate in the same or a similar condition as uric acid precipitates, whereas weddellite may precipitate in a different condition.
(17) Powder samples of 56 calcium oxalate stones the contents of weddellite, whewellite and apatite of which had been determined by thermogravimetry (TG) were studied by infrared spectroscopy (IR).
(18) The necessity of operative removal of calculi is still relatively high in the most frequent species of calculi whewellite, weddellite, uric acid, struvite and carbonate apatite.
(19) Whewellite (calcium oxalate monohydrate) crystals were found to induce epitaxially the heterogeneous nucleation of brushite (calcium monohydrogen phosphate dihydrate) from its metastable supersaturated solution in approximately one-quarter of the time required for spontaneous precipitation in the absence of added nucleating agents.
(20) Whewellite calculi were equally distributed in both race groups, while weddelite stones appeared to be much less common amongst blacks; the opposite applied for struvite and the rare ammonium acid urate stones.