(n.) A form of silica, or silicon dioxide (SiO2), occurring in hexagonal crystals, which are commonly colorless and transparent, but sometimes also yellow, brown, purple, green, and of other colors; also in cryptocrystalline massive forms varying in color and degree of transparency, being sometimes opaque.
Example Sentences:
(1) There fore, the adverse effects may be induced by such quartz or silicon compounds.
(2) We have previously shown that intratracheally instilled silica (quartz) produces both morphologic evidence of emphysema and small-airway changes, and functional evidence of airflow obstruction.
(3) Lung sections of rats exposed to quartz particles were significantly different.
(4) Exposures to quartz amounting to less than about 10 per cent of mixed coal mine dust do not generally affect the probability of developing simple pneumoconiosis.
(5) The effect of quartz, bentonite and coal dusts as well as the effect of the artificial mixture of these dusts on TTC reduction and extra-and intra-cellular lactate dehydrogenase activity in peritoneal rat macrophages was determined in vitro.
(6) Silica quartz dust, a direct toxin of macrophages, suppressed demyelination and inflammation if begun at time of virus infection.
(7) As expected the proportion of quartz was greater in lymph nodes and lungs from men who had worked "low" rank (high ash) coal.
(8) Guinea pig splenic lymphocytes and peritoneal macrophage cultures were incubated with quartz (DQ12), Corundum and aspirin as prostaglandin inhibitor.
(9) A surgical system using 308 nm excimer laser radiation transmitted by quartz fibers is described.
(10) Cancer incidence and cause-specific mortality were studied in a male cohort of 94 talc miners and 295 talc millers, exposed to non-asbestiform talc with low quartz content.
(11) The pulsed dye laser can effectively fragment biliary calculi when transmitted through a small-diameter quartz fiber and may be useful as a tool for fragmenting retained common duct stones.
(12) In mice bearing the highly metastatic tumors B16 melanoma and Lewis lung carcinoma (LLC) treated with Hpd and laser light delivered through a quartz fiber optic significantly prolonged the median survival time.
(13) With a long-term (1 and 4 months) introduction of an additional amount of edible fats (beef, hog fats, butter, sunflower seed oil) to intact and intratracheally quartz-dust laden sexually mature male rats an organ-specific reaction to the supply of fat, and in intact rats, also some peculiarities of the reaction depending upon the kind of the introduced fats, were discovered.
(14) Using a fluorescence microscope with quartz optics and an image analyser, it was possible to measure the intracellular concentration of free calcium ions [Ca2+]i in single microvessels for the first time.
(15) The median amount of quartz for all cases, was 0.044 grams.
(16) The microscope is focused on an in-line quartz flow cell incorporated down stream of a microbore HPLC column or directly on an optically clear portion of fused-silica capillary columns for analyte detection.
(17) X-ray diffraction data from samples of 20, 60 and 100 mug quartz on poly-vinyl chloride membrane filters have been collected using a rotating anode x-ray source.
(18) Mentally,” an Uber driver who used to do contract limo work told a reporter from business magazine Quartz last week, “these rating systems affect us a lot… If I am driving somebody who doesn’t live in New York, and they complain that I took the wrong route, how would they know the route that I should have taken?” He went on to note that in 20 years of working with corporate employees, he hadn’t a single customer complaining.
(19) There are closed relations between progressive systemic sclerosis (PSS) and exposure to quartz dust in the GDR.
(20) A 630 nanometer wavelength of light was delivered through a quartz-optical fiber with either a regular flat end for focal illumination or a bulb-type end which produced an isotropic light pattern.
Silica
Definition:
(n.) Silicon dioxide, SiO/. It constitutes ordinary quartz (also opal and tridymite), and is artifically prepared as a very fine, white, tasteless, inodorous powder.
Example Sentences:
(1) We have previously shown that intratracheally instilled silica (quartz) produces both morphologic evidence of emphysema and small-airway changes, and functional evidence of airflow obstruction.
(2) In the German Democratic Republic, patients with scleroderma and history of long term silica exposure are recognized as patients with occupational disease even though pneumoconiosis is not clearly demonstrated on X-ray film.
(3) Human gingival fibroblasts were allowed to attach and spread on bio-glasses for 1-72 h. Unreactive silica glass and cell culture polystyrene served as controls.
(4) The ADAM derivative of carnitine was separated from decomposition products of the reagent and related compounds such as amino acid derivatives on a silica gel column eluted with methanol-5% aqueous SDS-phosphoric acid (990:10:1).
(5) The deactivated columns had the residual silanols on the silica gel chemically inactivated to reduce the interaction with basic groups or analytes.
(6) We have investigated some of the factors which affect the retention times of these substances in reversed-phase HPLC on columns of 5-micron octadecylsilyl silica.
(7) The corresponding hydrides, mono-n-butyltin hydride, di-n-butyltin hydride, tri-n-butyltin hydride, monophenyltin hydride, diphenyltin hydride triphenyltin hydride, are detected by electron-capture gas chromatography after clean-up by silica gel column chromatography.
(8) The length of the hydrocarbon chains of the surface-modified silica supports had no significant influence on the selectivity.
(9) A novel type of ion exchanger was prepared by multipoint covalent binding of polystyrene chains onto the surface of porous silica followed by polymer-analogous modification of the bonded layer.
(10) The analytes were rapidly separated on an affinity column packed with phenylboronate-bonded silica.
(11) Using thin layer chromatography on fluorescent silica gel plates, 5 indoles were identified and 6 unknown substances isolated from the pineal incubate and from both extracts.
(12) Our results clearly demonstrate that capillary GC analysis of amino acids using fused silica bonded-phase columns provides data with good precision and in general excellent agreement with ion-exchange analyses.
(13) Free haem itself was bound to the silica column but could be released by globin.
(14) The methanol-ammonia (20:1) and chloroform-methanol-ammonia (2:2:1) systems, used with silica-gel plates, are the most promising for rapid preliminary screening of tuna fish extracts for histamine.
(15) The presence of Ca2+ in silica gel is responsible for this improved yield of prostaglandin as the divalent metal ion stabilized prostaglandin synthetase activity in a remarkable way.
(16) Silica accumulated linearly in the mediastinal lymph nodes and thymus for several months after cessation of exposure, while negligible amounts were found in kidney, spleen, liver, and blood.
(17) Methods employing electroosmotic flow in an untreated silica capillary were found to provide, at best, only partial resolution of the 23 fragments in a 1-kbp DNA ladder.
(18) The galactose lipid was isolated by column chromatography on DEAE-cellulose and silica gel.
(19) Adsorption experiments were performed by combining virus and silica in 0.1-ionic-strength buffers of pH 4.0, 6.4, and 8.5.
(20) The extracts are analyzed via a gas chromatograph equipped with a DB-1301 widebore fused-silica capillary column and an electron capture detector.