(n.) A rare sulphide of osmium and ruthenium found with platinum in Borneo and Oregon.
Example Sentences:
(1) Some 21 sovereign monarchs, and six representatives, made up the largest such gathering of foreign royals since Queen Victoria's golden jubilee celebrations, captured in a painting by Laurits Tuxen.
Ruthenium
Definition:
(n.) A rare element of the light platinum group, found associated with platinum ores, and isolated as a hard, brittle steel-gray metal which is very infusible. Symbol Ru. Atomic weight 103.5. Specific gravity 12.26. See Platinum metals, under Platinum.
Example Sentences:
(1) The actions of the polyvalent cationic dye Ruthenium Red and the enzyme neuraminidase were studied at the frog neuromuscular junction.
(2) Ruthenium red (RuR) inhibits Ca2+ uptake and transmitter release in synaptosomes, and produces flaccid paralysis when injected intraperitoneally (IP) and convulsions after intracranial administration.
(3) In the other case one eye was enucleated and the other irradiated with an episcleral ruthenium plaque.
(4) The results indicate that ruthenium red appears to protect against hepatocellular injury by inhibiting degradative proteolytic activity.
(5) A layer of thick and dense delicate filament-like substance was attached to the surface of the cell body of Cp in the ultrathin sections with ruthenium red staining, in the case of Cj only a little of such a substance could be noted.
(6) Addition of ruthenium red to mitochondria isolated from brain, adrenal cortex, parotid gland and skeletal muscle inhibits further uptake of Ca2+ by these mitochondria but induces little or no net Ca2+ efflux; the further addition of Na+, however, induces rapid efflux of Ca2+.
(7) It is also found to be sensitive to inhibition by tetraphenyl phosphonium, magnesium, and ruthenium red.
(8) The ruthenium red method was also used on a number of marine invertebrate embryos and larvae, representing different phyla, to facilitate comparisons between their surface coats.
(9) Ruthenium red is a widely used method for retaining and localizing proteoglycan for electron microscopy but its inability to produce sufficient density within the cells for light microscopy prevented simultaneous visualization by these two modes.
(10) For these experiments a substantial inhibition of the Ca2+ buffer capacity of the axoplasm was achieved by the use of Ruthenium red (10-20 microM), cyanide (1 mM) and vanadate (1 mM) in the dialysis solution.
(11) Their visualisation appeared to be enhanced when ruthenium red was incorporated n the glutaraldehyde-osmium fixative but only when sections were stained with heavy metal salts, indicating that the fimbriae and capsule were not predominantly polysaccharide in nature.
(12) In conclusion, ruthenium red selectively inhibits the capsaicin, resiniferatoxin and citric acid-induced excitation of the sensory nerves as revealed by calcitonin gene-related peptide-like immunoreactivity release, bronchoconstriction and coughing, suggesting that these agents share a common mechanism of action.
(13) Marked net cation loss and cell shrinkage occurred in the absence of a chemical gradient for Na and K. This voltage-dependent increase in Na and K conductance is partially inhibited by 10 microM ruthenium red and persists when the membrane potential is returned to -10 mV after transient exposure to inside-positive potentials.
(14) The ruthenium-metronidazole complex showed greater activity than metronidazole aerobically, but a higher differential activity under hypoxic reduction conditions, due to activation of the NO2 group.
(15) In the absence of Ca2+, CaM has two binding sites for ruthenium red with the dissociation constants of 0.36 and 8.7 microM, respectively.
(16) Light and electron microscopic examination of rabbit corneal lesions observed 4 to 6 h after the intracorneal injection of submicrogram amounts of the proteases revealed: (i) degeneration and necrosis of epithelium, endothelium, and keratocytes, (ii) infiltration, degeneration, and necrosis of polymorphonuclear leukocytes, (iii) loss of the characteristic weblike pattern, colloidal iron staining, and ruthenium red staining of the stromal proteoglycan ground substance, (iv) dispersal of strucutrally normal appearing collagen fibrils, ground substance, (iv) dispersal of structurally normal appearing collagen fibrils, and (v) accumulation of plasma proteins and fibrin in the necrotic corneas.
(17) It was unaffected by 0.3 microM tetrodotoxin (TTX), slightly reduced by 0.1 microM omega-conotoxin (CTX) and blocked by 10 microM Ruthenium red (RR).
(18) Alkalinization-induced Ca2+ release from isolated frog or rabbit sarcoplasmic reticulum vesicles appears to consist of two distinct components: 1) a direct activation of ruthenium red-sensitive Ca2+ release channels in terminal cisternae and 2) an increased ruthenium red-insensitive Ca2+ efflux through some other efflux pathway distributed throughout the sarcoplasmic reticulum.
(19) Ruthenium red staining was more intense on WF megakaryocytes and platelets, indicating a possible increase in surface mucopolysaccharides.
(20) Furthermore, ruthenium red alone acts as an anion-selective ionophore in lipid bilayers with the the following selectivity sequence for anions: l- greater than Cl-, Br- greater than F- greater than NO3-.