(n.) A pearly substance which lines the interior of many shells, and is most perfect in the mother-of-pearl. [Written also nacker and naker.] See Pearl, and Mother-of-pearl.
Example Sentences:
(1) When nacreous shell produced by the marine oyster Pinctada maxima, used as a biomaterial in oral surgery, is implanted in human bone, new bone formation occurs, resulting in a tight welding of the bone to the nacre [16].
(2) Dilute suspensions of normal erythrocytes exhibit a pearl-like sheen (nacre) when subjected to flow.
(3) Nacre implanted in vivo in bone is osteogenic suggesting that it may possess factor(s) which stimulate bone formation.
(4) These observations are discussed namely in relation to the problem of structural identification of the EDTA soluble fraction of the nacre conchiolin.
(5) To test this hypothesis, we have evaluated the effect of the simultaneous presence of bone and nacre on human osteoblasts in vitro.
(6) In other areas (along the main course of the mantle), transient adhesions between the outer mantle epithelial cells and the nacre appear to temporally further compartmentalize the extrapallial fluid possibly as a prerequisite for the initial crystallization phenomenon.
(7) Induction of mineralization appeared preferentially in bundles of osteoblasts surrounding the nacre chips.
(8) Nacre chips (1 mm3) were placed at approximately 1 mm distance from a similarly sized bone chip on a layer of first passage human osteoblasts.
(9) The five tissues, extracellularly mineralizing algae, radial and granular foraminifera, mammalian bone, mammalian enamel, and mollusk shell nacre, probably span the entire spectrum.
(10) The degree of nacre can be measured by comparing the intensity of scattered red light at an angle of 45 degrees for the flowing system to that when the effect has disappeared.
(11) The results demonstrated that nacre has strong osteogenic effects on human osteoblasts when placed in proximity to bone in vitro.
(12) These findings are consistent with the possibility that nacre adjacent to bone can locally stimulate osteogenic activity.
(13) These results demonstrate that a complete sequence of bone formation is reproduced when human osteoblasts are cultured in the presence of nacre.
(14) In addition, under the conditions of culture used, nacre can also promote the formation by osteoblasts of a structure with characteristics similar to nacre (e.g., lamellar organic matrix mineralized with aragonite, as demonstrated by Laser Raman Spectroscopy).
(15) Osteoblasts proliferated and were clearly attracted by nacre chips to which they attached.
(16) A woman exposed to the dust of sea-snail shells during the manufacture of nacre buttons had clinical and immunological features typical of hypersensitivity pneumonitis; however, transbronchial lung biopsy showed alveolar-septal amyloidosis.
(17) Nacre chips were placed on a layer of first passage human osteoblasts.
(18) The present study was undertaken to test the hypothesis that nacre can induce mineralization by human osteoblasts in vitro.
Opal
Definition:
(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.