(n.) A common mineral of a pale brass-yellow color and brilliant metallic luster, crystallizing in the isometric system; iron pyrites; iron disulphide.
Example Sentences:
(1) The ultrastructure of rabbit tracheal epithelium was studied 2, 8 and 26 hours after termination of 8-hour inhalation of ground pyrite dust.
(2) Evidence for the direct utilization of the sulphur moiety of pyrite by Thiobacillus ferrooxidans was derived from the following observations: a.
(3) An aerobic facultative thermophilic bacterium was isolated from the ore of the Nikolaev copper-zinc-pyrite deposit in the Eastern Kazakhstan.
(4) A research study was carried out at a pyrite mine in Niccioleta, southern Tuscany, during the period 1980-1983 to investigate the possible effects of gaseous and particulate pollutants on the respiratory function of mine workers.
(5) Wistar rats were injected intratracheally with pyrite particles and after 6 and 12 mo, lungs were evaluated for histological changes.
(6) Pyrite particles persist in the cytoplasm of ciliated cells throughout the interval followed up.
(7) It is proposed that the energy-transducing system of the first cellular organism and its precursor was fueled by the oxidation of hydrogen sulfide and ferric sulfide to iron pyrites and two [H+] on the outside surface of a vesicle (the cell membrane), with the concomitant reduction of CO or CO2 on the interior.
(8) A technique was developed for measuring (14)CO(2) uptake by chemolithotrophic bacteria directly in pyritic materials associated with coal and coal refuse.
(9) The cycle is catalytic for pyrite formation and autocatalytic for its own multiplication.
(10) The presence of high concentrations of sulfate, iron, and hydrogen (acid) ions in drainage from coal mines and other areas containing waste pyritic materials is a serious water pollution problem.
(11) The effect of pyrite added to the waste materials before the beginning of leaching has also been examined.
(12) The aforementioned importance is related to the ability of the bacterium to oxidize reduced iron and sulfur, principally found in nature as pyrite (FeS2).
(13) The morphogenesis of Sulfobacillus thermosulfidooxidans BKM B-1269 was studied by electron microscopy at the vegetative stage of growth on a medium with pyrite as the source of energy.
(14) Three species of thermophilic archaebacteria of the genera Sulfolobus (Sulfolobus acidocaldarius and S. solfataricus) and Acidianus (Acidianus brierleyi) were tested for their ability to oxidize pyrite and to grow autotrophically on pyrite, to explore their potential for use in coal desulfurization.
(15) These include: lack of controls while mining is underway; catastrophic events, such as the collapse of a settling dam, lack of site specific understanding of pyrite oxidation processes, particularly those that are biologically enhanced; the need for adequate biological information on which to base decisions to meet biological information on which to base decisions to meet biological objectives.
(16) Ferric, sulfate, and hydrogen ions are produced from pyritic minerals associated with coal as a result of autotrophic bacterial metabolism.
(17) A cohort mortality study was conducted with regard to a pyrite mine located in central Italy.
(18) They were skillful dental surgeons and made prostheses from jade and turquoise and filled teeth with iron pyrite.
(19) Only A. brierleyi was able to oxidize and grow autotrophically on pyrite.
(20) For instance, gold mining in South Africa’s Witwatersrand Basin – on which Johannesburg’s economy was founded – has left 120 mines’ worth of pyrite tailings, containing 450,000 tonnes of uranium.
Sulfur
Definition:
Example Sentences:
(1) Manometric studies with resting cells obtained by growth on each of these sulfur sources yielded net oxygen uptake for all substrates except sulfite and dithionate.
(2) Typically the iron-iron axis (gz) of the binuclear iron-sulfur clusters is in the membrane plane.
(3) Our study suggests that a major part of the renal antimineralocorticoid activity of spironolactone may be attributable to minor sulfur-containing metabolites or their precursors having a high renal clearance that affords access to their site of activity via the renal tubular fluid.
(4) Ferredoxin reductase (Fd-reductase) supplies reducing equivalents obtained from NADPH to mitochondrial cytochrome P450 enzymes via the small iron-sulfur protein ferredoxin.
(5) The loss of enzyme activity in sulfur-rhodanese does not involve cysteinyl residues but can be correlated with the modification of guanidino groups, notably that of Arg-186, the side chain of which may play a role in substrate binding.
(6) In two patients with extensive marrow necrosis, the diagnosis of marrow necrosis was established by morphologic and radioisotopic studies, and the extent of involvement was accurately assessed by marrow scanning with technetium Tc 99m sulfur colloid while the patients were still alive.
(7) It was presumed that thymohydroquinone is excreted as ethereal sulfuric acid conjugate in man.
(8) Also purple sulfur bacteria lowered BOD levels as demonstrated by the growth of T. floridana in sterilized sewage.
(9) An equivalent maximum growth response of rats fed L-methionine or N-acetyl-L-methionine was obtained when the total dietary sulfur amino acids compromised 0.36-0.41% of the diet.
(10) Histopathological evaluations showed that sulfuric acid particles alone did not cause inflammatory responses in centriacinar units of rat lung parenchyma (expressed in terms of percent lesion area) but did cause significant damage (cell killing followed by a wave of cell replication) in nasal respiratory epithelium, as measured by uptake of tritiated thymidine in the DNA of replicating cells.
(11) Ac-MPS of the hyaluronic acid type prevail in the ground substance of the myxoid and fibroblastic mesenchyma, while the substances containing sulfuric groups predominate in the tissue matrix exhibiting fibrogenic tendencies.
(12) Previous work demonstrated a differential decrease in iron-sulfur centers A, B and X which indicated that center X serves as a branch point for parallel electron flow through centers A and B (Golbeck, J.H.
(13) Our observation leads to the suggestion that, in vivo, either rhodanese is maintained in its more stable sulfur-substituted form or cellular compartmentalization prevents inactivation by nitrite.
(14) In contrast, the (Rp)-isomers, which have an equatorial exocyclic sulfur atom, bound to the enzyme without stimulation of its activity.
(15) A strong shoulder was observed at 2481.7 eV on the low-energy side of the sulfate absorption edge, deriving from a novel type of sulfur having a slightly lower oxidation state than sulfate sulfur.
(16) Long-term treatment with furosemide (up to 13 months) caused transient changes in the elemental content of the pancreatic acinar cells: a decrease in chloride and sulfur, and an increase in phosphorus, potassium and magnesium.
(17) The iron-sulfur proteins of the green photosynthetic bacterium Chlorobium have been characterized by oxidation-reduction potentiometry in conjunction with low-temperature electron paramagnetic resonance spectroscopy.
(18) The reaction is based on the reduction of sulfur dioxide at a dropping mercury electrode.
(19) Proton induced X-ray emission (PIXE) analyses were performed on single hair fibers in triplicate from 103 individuals in order to determine sulfur, zinc, calcium, and chlorine content.
(20) In a survey of the proteins from human hair, a genetic electrophoretic variant has been observed in the high-sulfur protein region.