(n.) A common mineral embracing many varieties varying in color and in composition. It occurs in monoclinic crystals; also massive, generally with fibrous or columnar structure. The color varies from white to gray, green, brown, and black. It is a silicate of magnesium and calcium, with usually aluminium and iron. Some common varieties are tremolite, actinolite, asbestus, edenite, hornblende (the last name being also used as a general term for the whole species). Amphibole is a constituent of many crystalline rocks, as syenite, diorite, most varieties of trachyte, etc. See Hornblende.
Example Sentences:
(1) Three subcohorts were defined: 3212 men whose only exposure to asbestos was to amosite; 3430 exposed to crocidolite; and 675 to both amphiboles.
(2) Amphibole fibre counts were raised when compared with a non-occupationally exposed group and matched those seen in cases of pleural plaques, mild asbestosis, and mesothelioma.
(3) The second, with amphibole or glassy fibres, is mediated by fibronectin which first binds to the fibre.
(4) Six measures of asbestos-in-air concentration were considered: (1) total asbestos structures per cubic centimeter: (2) chrysotile structures per cubic centimeter; (3) amphibole structures per cubic centimeter; (4) structures per cubic centimeter at least 0.5 micron long and at least five times wide; (5) structures per cubic centimeter at least 5 microns long; and (6) structures per cubic centimeter at least 5 microns long and at least 0.2 micron wide.
(5) The ingestion of filtered water results in the eventual disappearance of amphibole fibers from urine.
(6) When fibre-length distributions were calculated using a scanning electron microscope, however, it was found that the chrysotile clouds used in this study contained many more fibres over 20 microgram long than either of the amphibole clouds.
(7) A suitable quarry was found about 11 km from the port but unfortunately the rock was found to be contaminated to a small extent with a fibrous mineral identified with the analytical transmission electron microscope as a non-commercial type of fine amphibole with many long fibres.
(8) The most positive lavages, probably reflecting exposure to industrial amphiboles, were found in patients presenting with radiological evidence of asbestosis.
(9) The amphibolic asbestos types lie in the upper half and the rock wool sample in the lower half of the range.
(10) Based on the results obtained, the following metabolic pathway is proposed: isopropylbenzene----2,3-dihydro -2,3-dihydroxyisopropylbenzene----3-isopropylcatechol----2 -hydroxy-6-oxo-7-methylocta-2,4-dienoate----isobutyrate + 2-oxopent-4-enoate----amphibolic intermediates.
(11) While amphibole cleavage fragments are usually visible by PCM, asbestos fibers (such as amosite and chrysotile) have finer widths that may render them invisible by PCM.
(12) In general, chrysotile had a toxic effect on the macrophages, whereas amphibole varieties did not.
(13) Of particular importance is an apparent increase in the proportion of mesothelioma risk attributable to tremolite, since the fibers heretofore most responsible for that disease--commercial amphiboles--have been or are being severely regulated or completely eliminated in production and use.
(14) The first reported case was a village woman whose lung tissue contained amphibole asbestos fibres, which were later identified as tremolite.
(15) Crocidolite fiber, a commercial amphibole not native to the region, was nonetheless identified in lung tissue from 15 of 23 chrysotile miners and millers.
(16) There was a rather good correlation between numbers of amphibole fibers and asbestos bodies, with an average ratio of 10:1.
(17) Chrysotile asbestos was much more active in binding IgG than was amphibole asbestos.
(18) Analytical electron microscopy of asbestos body cores showed that in the BL group 95.6% were chrysotile fibres whereas in the AC group amphiboles accounted for 93.1%.
(19) The magnesium amphibole contained the longest (6.03 microns) fibres, and the nickel amphibole contained the shortest (2.7 microns) fibres, resembling those of crocidolite.
(20) Electron microscopic examination of these water samples confirms the presence of asbestiform amphibole fibers.
Silicate
Definition:
(n.) A salt of silicic acid.
Example Sentences:
(1) Folch extraction and partition followed by silicic acid column chromatography revealed the antigens to be glycolipids.
(2) The UE and KE fractions were then separated by silicic acid column chromatography with a stepwise elution method using ether-hexane.
(3) Increased levels of influenza virus multiplication concomitant with decreased levels of interferon occurred in cell monolayers pretreated with silicates.
(4) The dissolution t50 and various pharmacokinetic parameters showed directly compressible starch and carboxymethylstarch to be the most effective disintegrants in the concentrations employed while magnesium aluminum silicate and microcrystalline cellulose were about equal but less effective than the previous disintegrants.
(5) As with SRS-A, pSRS could be absorbed onto Amberlite XAD-2 and silicic acid.
(6) The in vivo experiments confirmed previous reports concerning unfavourable pulp reaction caused by silicate cement, while the glass ionomer cement caused mainly a mild pulp reaction after 8 days of observation.
(7) The results are negative in swampy meadow -- habitats on siliceous soils.
(8) The origin of aluminum silicate inclusions in pulmonary macrophages has yet to be determined, although preliminary evidence strongly suggests that they are derived from inhaled tobacco smoke.
(9) Purification was achieved by sequential use of partitioning in solvents, DEAE-Sephadex chromatography, base treatment, and silicic acid chromatography.
(10) Chromatography of rat-liver lipids on a column of silicic acid or a mixture of silicic acid and Hyflo Super-Cel, with chloroform-methanol mixtures, gave monophosphoinositide-containing fractions which were invariably contaminated by the presence of nitrogen-containing phospholipids.
(11) Hemolysis from silicates is decreased by interventions which remove superoxide anion or hydrogen peroxide from the medium, or by pretreatment of dusts with iron chelators.
(12) Condensation of 1,2,3,4,6-penta-O-acetyl-beta-D-galactopyranose with benzyl 2-azido-4,6-di-O-benzyl-2-deoxy-beta-D-galactopyranoside in the presence of trimethylsilyl triflate gave crystalline benzyl 2-azido-4,6-di-O-benzyl-2-deoxy-3-O-(2,3,4,6-tetra-O-acetyl-beta-D-ga lactopyranosyl)-beta-D-galactopyranoside (76%), which was converted into benzyl 2-azido-4,6-di-O-benzyl-2-deoxy-3-O-(2,6-di-O-benzyl-beta-D-galactopy ranosyl)-beta-D-galactopyranoside and condensed with 3,4,6-tri-O-acetyl-2-azido-2-deoxy-alpha-D-galactopyranosyl bromide in the presence of silver silicate on alumina and molecular sieve 4 A to give 61% of benzyl O-(3,4,6-tri-O-acetyl-2-azido-2-deoxy-beta-D-galactopyranosyl)-(1----4)- O-(2,6-di- O-benzyl-beta-D-galactopyranosyl)-(1----3)-2-azido-4,6-di-O-benzyl-2-deo xy- beta-D-galactopyranoside.
(13) Total neutral and acidic glycosphingolipids were prepared from whole tissues of the sea-water bivalve, Meretrix lusoria, and the former preparation was further fractionated into subgroups by silicic acid column chromatography.
(14) Talc (magnesium silicate) is a widely used, generally considered benign substance.
(15) Silica is a component of talc (magnesium silicate) used as a drug filler.
(16) Silicic acid could, by hydrogen bonding, alter the conformation of organic macromolecules, since hydrogen bond association can inhibit silanol condensation.
(17) A novel phosphonoglycosphingolipid named SGL-I' containing 1 mol of 2-aminoethylphosphonate residue was isolated from the skin of Aplysia kurodai using two silicic acid chromatography systems.
(18) Treatment of exposed dentin with calcium hydroxide reduced the pulp irritating effect of silicate cement restorations, but induced only limited volumes of irregular secondary dentin formation.
(19) The activity to induce IgE antibody production by fly ash instillation was almost the same as that by aluminum silicate, studied previously.
(20) Isolated cells from the siliceous sponge Geodia cydonium as well as small primary aggregates (diameter: 70 mum) consisting of them show no increase in rates of programmed syntheses and mitotic activity with time.