(n.) A variety of amphibole or of pyroxene, occurring in long and delicate fibers, or in fibrous masses or seams, usually of a white, gray, or green-gray color. The name is also given to a similar variety of serpentine.
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) Trichophytosis (T. equinum) is characterized as typical numerous small and round patches, covered by small, bran-like, asbestos-coloured scales.
(3) Using recently published data from the Surveillance, Epidemiology, and End Results project, coupled with the previously published estimates, projected asbestos related malignant mesothelioma mortality in the United States for the period 1985-2009 was estimated to be 21,500.
(4) Crocidolite asbestos fibers are rapidly ingested in large amounts by Tetrahymena.
(5) The benign localized mesothelioma is usually considered in the differential diagnosis of pleural tumors, but it is not related to asbestos exposure.
(6) This study examined different markers of lung immunologic and inflammatory responses to previous asbestos exposure.
(7) The role of alveolar macrophage (AM)-derived secretory products in fibroblast stimulation after the instillation of long and short asbestos to rat lungs is now investigated.
(8) Attention to the hazards of asbestos has aroused concern among many healthy persons who have been exposed at some time to one of the world's most versatile materials.
(9) The high sites' density with basic character, evidenced by use of various probe molecules, is very similar for the two asbestos types (chrysotile and crocidolite) and on the same order as the density encountered in some catalysts.
(10) Categorization of the pattern of physiologic abnormalities in patients with asbestos-associated disease may be important for clinical, compensation, and epidemiologic reasons.
(11) These results have been compared with asbestos samples obtained from the National Institute of Environmental Health Sciences (NIEHS).
(12) Results indicated that the percentage of S cells was similar in asbestos-treated and untreated cultures.
(13) The various neoplasms attributed to asbestos in the next decades posed an additional question: What influence did the fibrous shape of the particles have on carcinogenic potential?
(14) In 1964 it was first reported that asbestos workers had a higher risk of gastrointestinal cancer.
(15) There is no doubt that the presence of asbestos in the coal mine is one of the pathogenic factors of pneumoconiosis.
(16) We examined whether exposure of macrophages to crocidolite asbestos induced lipid peroxidation as measured by the thiobarbituric acid assay.
(17) The findings suggest widespread exposure to asbestos dust; occupational histories appeared to indicate the source of exposure in some but not all patients.
(18) The present standard method for evaluating asbestos fiber concentrations in workroom air excludes fibers less than 5 micron long even though it has been shown that small fiber concentrations dominate in a dust cloud.
(19) Among patients with mesothelioma a history of asbestos exposure was obtained in 44%, a history of no exposure in 22% and no specific mention of asbestos in 34%.
(20) Previous suggestions for converting TEM measurements to PCM equivalents lack generality because they fail to take into account the size distribution of the asbestos particles and the expectation that fiber-size distributions in current nonoccupational environments could differ from the workplaces of the past on which the risk equations are based.
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.