(n.) A form of silica, or silicon dioxide (SiO2), occurring in hexagonal crystals, which are commonly colorless and transparent, but sometimes also yellow, brown, purple, green, and of other colors; also in cryptocrystalline massive forms varying in color and degree of transparency, being sometimes opaque.
Example Sentences:
(1) There fore, the adverse effects may be induced by such quartz or silicon compounds.
(2) 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.
(3) Lung sections of rats exposed to quartz particles were significantly different.
(4) Exposures to quartz amounting to less than about 10 per cent of mixed coal mine dust do not generally affect the probability of developing simple pneumoconiosis.
(5) The effect of quartz, bentonite and coal dusts as well as the effect of the artificial mixture of these dusts on TTC reduction and extra-and intra-cellular lactate dehydrogenase activity in peritoneal rat macrophages was determined in vitro.
(6) Silica quartz dust, a direct toxin of macrophages, suppressed demyelination and inflammation if begun at time of virus infection.
(7) As expected the proportion of quartz was greater in lymph nodes and lungs from men who had worked "low" rank (high ash) coal.
(8) Guinea pig splenic lymphocytes and peritoneal macrophage cultures were incubated with quartz (DQ12), Corundum and aspirin as prostaglandin inhibitor.
(9) A surgical system using 308 nm excimer laser radiation transmitted by quartz fibers is described.
(10) Cancer incidence and cause-specific mortality were studied in a male cohort of 94 talc miners and 295 talc millers, exposed to non-asbestiform talc with low quartz content.
(11) The pulsed dye laser can effectively fragment biliary calculi when transmitted through a small-diameter quartz fiber and may be useful as a tool for fragmenting retained common duct stones.
(12) In mice bearing the highly metastatic tumors B16 melanoma and Lewis lung carcinoma (LLC) treated with Hpd and laser light delivered through a quartz fiber optic significantly prolonged the median survival time.
(13) With a long-term (1 and 4 months) introduction of an additional amount of edible fats (beef, hog fats, butter, sunflower seed oil) to intact and intratracheally quartz-dust laden sexually mature male rats an organ-specific reaction to the supply of fat, and in intact rats, also some peculiarities of the reaction depending upon the kind of the introduced fats, were discovered.
(14) Using a fluorescence microscope with quartz optics and an image analyser, it was possible to measure the intracellular concentration of free calcium ions [Ca2+]i in single microvessels for the first time.
(15) The median amount of quartz for all cases, was 0.044 grams.
(16) The microscope is focused on an in-line quartz flow cell incorporated down stream of a microbore HPLC column or directly on an optically clear portion of fused-silica capillary columns for analyte detection.
(17) X-ray diffraction data from samples of 20, 60 and 100 mug quartz on poly-vinyl chloride membrane filters have been collected using a rotating anode x-ray source.
(18) Mentally,” an Uber driver who used to do contract limo work told a reporter from business magazine Quartz last week, “these rating systems affect us a lot… If I am driving somebody who doesn’t live in New York, and they complain that I took the wrong route, how would they know the route that I should have taken?” He went on to note that in 20 years of working with corporate employees, he hadn’t a single customer complaining.
(19) There are closed relations between progressive systemic sclerosis (PSS) and exposure to quartz dust in the GDR.
(20) A 630 nanometer wavelength of light was delivered through a quartz-optical fiber with either a regular flat end for focal illumination or a bulb-type end which produced an isotropic light pattern.
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.