(n.) An element obtained by reduction of its oxide, as a hard, grayish white metal, fusible with difficulty, but easily oxidized. Its ores occur abundantly in nature as the minerals pyrolusite, manganite, etc. Symbol Mn. Atomic weight 54.8.
Example Sentences:
(1) This result was confirmed by atomic absorption spectroscopy, which indicated a stoicheiometry for copper and manganese of approx.
(2) Although GTP most potently inhibited [125I]beta h-endorphin binding in the presence of sodium, inhibition of [125I]beta h-endorphin binding by GTP was also observed in the presence of the monovalent cations lithium and potassium, but not the divalent cations magnesium, calcium, or manganese.
(3) In the present study, maternal and fetal zinc (Zn), copper (Cu), manganese (Mn), iron (Fe), magnesium (Mg), and calcium (Ca) status has been studied in Sprague-Dawley (SD) and Wistar rats.
(4) The subjects were exposed to manganese, iron , chromium compounds, thermal radiation, high temperature and noise.
(5) Experiments were conducted with young chicks to investigate the effect of various feed ingredients on manganese (Mn) bioavailability.
(6) The method was tested by using monolayers of alveolar macrophages from rabbits exposed to manganese dioxide particles.
(7) In order to determine the specific action of cadmium on bone metabolism, the effect of cadmium on alkaline phosphatase activity, a marker enzyme of osteoblasts, was compared with that of other divalent heavy metal ions, i.e., zinc, manganese, lead, copper, nickel and mercury (10 microM each), using cloned osteoblast-like cells, MC3T3-E1.
(8) The manganese peroxidase (MnP), from the lignin-degrading fungus Phanerochaete chrysosporium, an H2O2-dependent heme enzyme, oxidizes a variety of organic compounds but only in the presence of Mn(II).
(9) The manganese-containing (MnSOD) and iron-containing (FeSOD) superoxide dismutases from Escherichia coli are extensively (greater than 95%) inactivated by treatment with phenylglyoxal.
(10) It is suggested that there is a fundamental difference between magnesium and manganese in the activation of the enzyme.
(11) Chronic dietary deficiency of calcium (Ca) and magnesium (Mg) with excessive intake of aluminum (Al) and manganese (Mn) has been implicated in the pathogenesis of high incidence amyotrophic lateral sclerosis (ALS) in the Western Pacific.
(12) RNA synthesis required all four ribonucleoside triphosphates and was dependent on magnesium or manganese; optimal activity required potassium or ammonium ions.
(13) The stimulatory effects of manganese were inhibited by calcitonin but not by indomethacin.
(14) Electron spin resonance (ESR) spin trapping methodology has been used to study the reactions of manganese dusts with glutathione, employing alpha-(4-pyridyl-1-oxide)-N-tert-butyl-nitrone (PBN) and 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) as spin traps.
(15) Because DMP oxidation by this enzyme is only slightly inhibited by Mn2+, this substrate should not be used in assays to detect manganese peroxidase.
(16) A major disruption in primary metabolism and hence secondary metabolism was discounted since eight primary metabolism enzymes showed no evidence of unusual changes in specific activity when normal and manganese-deficient cultures were compared.
(17) Local cobalt (Co2+) or manganese (Mn2+) applications could abolish amino acid-evoked [Ca2+]o changes, whereas most of the [K+]o changes persisted.
(18) Previous studies in neonatal and suckling animals showed that immature animals have a greatly diminished capacity to excrete manganese and therefore were considered to be unable to regulate tissue manganese concentrations.
(19) The influence of the electric field of commerical frequency on metabolism and interorgan distribution of copper, molybdenum, iron and manganese was studied in the 4-month experiment on animals with their daily 30-minute exposition.
(20) Manganese therefore acts as a catalyst for the non-enzymatic reaction, but magnesium does not.
Pyrolusite
Definition:
(n.) Manganese dioxide, a mineral of an iron-black or dark steel-gray color and metallic luster, usually soft. Pyrolusite parts with its oxygen at a red heat, and is extensively used in discharging the brown and green tints of glass (whence its name).
Example Sentences:
(1) Two schemes are discussed: treatment of the sewage in an electrolysis plant followed by its afterpurification either in a column with pyrolusite or during a joint process of electrochemical purification with catalyst location on the plant bottom under the electrodes.
(2) The afterpurification of electrochemically treated liquid sewage on waste pyrolusite can provide and additional effect i.e.
(3) In the paper the morphological characters, physical properties and spectral analyses(IR,AES) of seven samples collected from different regions are investigated by means of comparison with reference standard pyrolusite.