(n.) An important ore of iron, the sesquioxide, so called because of the red color of the powder. It occurs in splendent rhombohedral crystals, and in massive and earthy forms; -- the last called red ocher. Called also specular iron, oligist iron, rhombohedral iron ore, and bloodstone. See Brown hematite, under Brown.
Example Sentences:
(1) The third aerosol, "gamma-oxide," has a MMAD of 0.73 micrometer and has crystalline subunits 0.2 micrometer in diameter; it is a magnetic form of hematite, gamma-Fe2O3.
(2) This case-control (case-referent) study concerns a worker population with high exposure to dust of iron oxides, particularly hematite, and with some impurities of pentavalent arsenic and other metals.
(3) The iron-oxides (superfine hematite) are eroded from the Peron Sandstone exposed in some coastal cliffs and constitute up to 2% of substrate sediments near these cliffs.
(4) Inside the molluscs, lower pH conditions cause reversal of the hematite charge and the cadmium is released and accumulated by the organism.
(5) These fungi were incubated with the following iron-containing minerals: augite, hornblende, biotite, magnetite, hematite, and the igneous rock granodiorite.
(6) The "feathers" hematite has a man median aerodynamic diameter (MMAD) of 0.17 micrometer and a large surface area because it is an agglomerate of units 0.005 micrometer in diameter.
(7) Slate is a metamorphic rock comprising silica, aluminum silicates, and small amounts of chlorite, hematite, magnetite, and various carbonates.
(8) In a retrospective cohort mortality study of 10,403 Minnesota iron-ore (hematite) miners no excesses of lung cancer mortality were found among either underground (Standardized mortality ratio [SMR] = 100) or above ground (SMR = 88) miners.
(9) The "birdshot" hematite has a MMAD of 0.31 micrometer, but has a smaller surface area because the subunits are 0.03 micrometer in diameter.
(10) Fibrous dusts (chrysotile, glass fibers, nemalite, palygorscite, and gypsum) and granular dusts (actinolite, biotite, hematite, pectolite, sanidine, and talcum) were injected intraperitoneally into rats.
(11) The mortality risk of nonmalignant respiratory disease among hematite workers in the Longyan and Taochong mines of China was investigated in a retrospective cohort study covering the period 1970-1982.
(12) No direct link between the cadmium loads in molluscs and its concentration in the water or substrate sediment is evident, but the cadmium load in molluscs is usually highest where turbulence is high and the substrate sediment contains fine hematite.
(13) Iron oxides, particularly hematite, have been suspected for carcinogenic properties based on epidemiological observations and experimental data.
(14) This study reveals that cadmium in the water adsorbs extremely efficiently onto the surface of the hematite, which is negatively charged at the prevailing seawater pH of 8.15, and that suspended hematite particles are ingested by the molluscs.
Magnetite
Definition:
(n.) An oxide of iron (Fe3O4) occurring in isometric crystals, also massive, of a black color and metallic luster. It is readily attracted by a magnet and sometimes possesses polarity, being then called loadstone. It is an important iron ore. Called also magnetic iron.
Example Sentences:
(1) Silicone coated magnetite of nanometeric size was incorporated in the drug bearing microspheres.
(2) However, two developments during the past decade have changed this perception dramatically, the first being the discovery that many organisms, including humans, biochemically precipitate the ferrimagnetic mineral magnetite (Fe3O4).
(3) The results of this experiment show that the "biological magnetite" is distinctly different from hemosiderin and has characteristic properties when subjected to a magnetic field.
(4) Viable spermatozoa were isolated from magnetite-complexed spermatozoa, but the motility of the isolated spermatozoa deteriorated rapidly during the subsequent capacitation period.
(5) Magnetite (Fe3O4) particles 0.1-0.5 microns in diameter doped with either 99mTc or 111In have been prepared and characterized by electron microscopy and Mössbauer spectroscopy.
(6) The water relaxation ability of ferromagnetic, albumin-coated magnetite (Fe3O4) particles has been investigated.
(7) So far, identification of magnetite in tissue has been mainly based on magnetometry.
(8) By conjugating a monoclonal IgM antibody of CD8-specificity to magnetite-containing polymer particles, we have developed a rapid and simple one-step procedure for positive selection of T8 cells.
(9) A magnetic immobilized lactase has been prepared using magnetite as the magnetic material.
(10) Hydrolytic polymerization of iron(III) occurs in many reactions in vivo, for example, the formation of bacterial magnetite in magnetotactic organisms, biomineralization of iron and the synthesis of the metallic core of the iron-storage protein ferritin.
(11) X-ray diffraction patterns show that the mature denticles of three extant chiton species are composed of the mineral lepidocrocite and an apatite mineral, probably francolite, in addition to magnetite.
(12) The latter structures consist of nanometer-sized magnetite (Fe3O4) cores which are enwrapped by a phospholipid bilayer.
(13) We found significant quantities of single-domain magnetite in connective tissue from the ethmoid region of the skull of adult (4-year-old) sockeye salmon.
(14) The adhesion of cells of Salmonella typhimurium to albite, biotite, felspar, magnetite and quartz was correlated to the presence of fimbriae and degree of hydrophobicity and charge of the bacterial surface.
(15) We suggest that tissue from within the ethmoid region of the skull in pelagic fishes is the only site yet identified where magnetite suitable for use in magnetoreception is concentrated.
(16) This report describes the preparation and characterization of synthetic ferritin-like particles produced by precipitation of magnetite from a mixture of ferrous and ferric ions in the presence of dextran.
(17) The polyvinylamine-magnetite pellicle shielded the external plasma membrane face to proteolysis by papain and pronase.
(18) First, a method to produce a stable condition of hydrostatic pulmonary edema was developed and verified by CT. Second, dose-response curves for coated magnetite preparations were constructed by giving edematous rats varied doses of these preparations and measuring signal intensity changes of various organs by sodium MRI in a 31-cm-bore 1.9-T magnet.
(19) By the smolt stage, the amount of magnetite present in the front of the skull is sufficient to provide the fish with a magnetoreceptor capable of detecting small changes in the intensity of the geomagnetic field.
(20) The carrier consists of human serum albumin microspheres, average of 1 micrometer in diameter, in which a magnetizable material (magnetite) and a prototype drug (doxorubicin) are entrapped.