(n.) A mineral consisting, like quartz, of silica, but inferior to quartz in hardness and specific gravity.
Example Sentences:
(1) Several suppressors (suhD) that can specifically suppress the temperature-sensitive opal rpoH11 mutation of Escherichia coli K-12 have been isolated and characterized.
(2) Oligonucleotide-directed mutagenesis was used to generate amber, ochre and opal suppressors from cloned Arabidopsis and Nicotiana tRNA(Tyr) genes.
(3) The presence of 5' homologies flanking only the transcribed genes and not the pseudogenes suggests that these regions may be regulatory control elements specifically involved in the expression of the eukaryotic opal suppressor gene.
(4) The nonsense mutants of S. pombe have been classified according to their suppressibility by defined opal and ochre suppressors into a class of efficiently suppressed opal and a class of inefficiency suppressed ochre mutants.
(5) The opal suppressor form shows moderate suppressor activity when the gene is introduced on this vector, however, the ochre suppressor form exhibits no detectable biological activity regardless of gene copy number.
(6) The rabbit genome encodes an opal suppressor tRNA gene.
(7) Using such an assay, we provide the first direct evidence that an opal suppressor tRNA gene is functional in mammalian cells.
(8) The growth patterns of nonsense mutants of RNA (GA and f2) and DNA (lambda and T4) phages suggested that KO1 carried an amber, but not ochre or opal suppressors.
(9) Opal suppressor tRNA did not accept any selenocysteine and phosphoseryl-tRNA did not change to selenocysteyl-tRNA.
(10) We report here the construction of a detailed genetic and physical map of these genes, the neighboring gene 4 and a portion of gene 10, in which 289 conditional lethal amber, opal, temperature sensitive and cold sensitive mutations are mapped into 44 small (several hundred base pair) intervals of known sequence.
(11) More than half a million people have joined the Open Air Laboratories (Opal) citizen science project, designed to get people outdoors and involved in scientific research, since its launch in 2007.
(12) We studied the above mechanisms using opal suppressor tRNA in mammals.
(13) Two mutations, Cys-318 to an opal termination codon and Cys-319 to Ser-319, were created in vitro and substituted in the chromosome in place of the normal RAS2 allele.
(14) The important role of G73 in tryptophan identity was confirmed using mutants of an opal suppressor derivative of tRNA(Trp).
(15) This study has been undertaken in order to elucidate the mechanisms of incorporation of Se into glutathione peroxidase (GSHPx), in which selenocysteine corresponds to the opal termination codon UGA on the mRNA.
(16) An opal suppressor of tRNA(Gln) (su+2UGA) containing C35 (anticodon UCA) was isolated by genetic selection and mutagenesis.
(17) A proposal of the role of animal opal suppressor phosphoseryl (Ps)-tRNA is that Ps-tRNA plays a role as an intermediate in the metabolic pathway from 3-phosphoglycerate to glycine.
(18) Suppressor [32P]phosphoseryl-tRNA, prepared using bovine seryl-tRNA synthetase and ATP:seryl-tRNA phosphotransferase, was mixed with rabbit reticulocyte lysates containing endogenous hemoglobin mRNA having the termination codon UGA (opal).
(19) OPAL concept (Old People With Active Life styles) recommends an individualized establishment of therapy instead of standard techniques to try the minimal trouble to a good quality of life for the patient.
(20) "It is so well understood, so embedded in the psyche, that people make jokes about Opal Fruits and Jammy Dodgers being one of your five a day.
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.