(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.
Silicon
Definition:
(n.) A nonmetalic element analogous to carbon. It always occurs combined in nature, and is artificially obtained in the free state, usually as a dark brown amorphous powder, or as a dark crystalline substance with a meetallic luster. Its oxide is silica, or common quartz, and in this form, or as silicates, it is, next to oxygen, the most abundant element of the earth's crust. Silicon is characteristically the element of the mineral kingdom, as carbon is of the organic world. Symbol Si. Atomic weight 28. Called also silicium.
Example Sentences:
(1) There fore, the adverse effects may be induced by such quartz or silicon compounds.
(2) Of all materials evaluated, Xantopren Blue and Silene silicone impression materials provided the best results in vivo.
(3) We describe an enzymatic fluorometric method for determining glucose concentrations in blood samples by analysis on a semi-solid surface (silicone-rubber pads).
(4) Silicon, a relatively unknown trace element in nutritional research, has been uniquely localized in active calcification sites in young bone.
(5) A critical attitude towards the use of silicone breast implants, when these are used for purely cosmetic purposes, is recommended at present.
(6) An in vitro, eccentric arterial stenosis model was created using 15 canine carotid arteries cannulated with silicone plugs containing special pressure-transducing catheters designed to measure pressure directly, within the stenosis.
(7) The scaphoid silicone implant bore significant, although less, load than the normal scaphoid.
(8) A visual acuity of 0.05 or better was achieved in 36% of the eyes treated with silicone oil versus 67% of the eyes treated with gas tamponade.
(9) The biocompatibility and fixation of a new silicone intraocular lens was evaluated in the cat eye.
(10) The numbers in the holey tube regenerate are statistically different from normal but they are closer to normal than after similar regeneration in a regular silicone tube.
(11) Silicon levels tend to be higher in foods derived from plants than in foods from animal sources.
(12) The most common complications in breast augmentation surgery with homologous fat grafts obtained from fresh cadavers are presented, showing subsequent surgical procedures to reconstruct the breasts of such patients through use of silicone prostheses and muscle flaps from the latissimus dorsi.
(13) The lid is fiddly to fit on to the cup, and smells so strongly of silicone it almost entirely ruins the taste of the coffee if you don’t remove it.
(14) Perry and I are on our way to the Silicon Drinkabout , a get-together for anyone connected to the tech scene, hosted every week by a different local bar.
(15) A further increase in silicon dioxide concentration produced tablets with relatively larger pore sizes.
(16) Porous polyethylene was thus better incorporated into the soft tissues than silicone rubber as long as the overlying soft tissues were not stressed by an oversized implant or inadequate soft tissue coverage.
(17) Obliteration of the empty sella with an extradural silicone balloon via the transsphenoidal approach seemed to have been effective for headache and visual complaints of primary empty sella syndrome which did not respond to medical therapy.
(18) Mice were exposed to hypoxia by enclosure in cages covered with dimethyl-silicone rubber membranes for 1-14 days.
(19) Mid-shaft sections of 100% silicone (Bardex) and hydrogel-coated latex (Biocath) catheters were subjected to controlled in vitro encrustation conditions for periods of up to 18 weeks.
(20) "Posterior collagenous layer" was observed subendothelial in eyes injected with various silicone oil fluids including highly purified one.