This is ascribed to electron exchange between the FeII and FeIII centres in Fe3O4. Uses
Fe3O4 is used as a black pigment and is known as C.I pigment black 11 (C.I. No.77499) or Mars Black.Fe3O4 is used as a catalyst in the Haber process and in the water-gas shift reaction. The latter uses an HTS (high temperature shift catalyst) of iron oxide stabilised by chromium oxide. This iron–chrome catalyst is reduced at reactor start up to generate Fe3O4 from α-Fe2O3  and Cr2O3 to CrO3.Bluing is a passivation process that produces a layer of Fe3O4 on the surface of steel to protect it from rust. Along with sulfur and aluminium, it is an ingredient in steel-cutting thermite. Medical uses
Nano particles of Fe3O4 are used as contrast agents in MRI scanning.Ferumoxytol, sold under the brand names Feraheme and Rienso, is an intravenous Fe3O4 preparation for treatment of anemia resulting from chronic kidney disease. Ferumoxytol is manufactured and globally distributed by AMAG Pharmaceuticals. Biological occurrence
Magnetite has been found as nano-crystals in magnetotactic bacteria (42–45 nm) and in the beak tissue of homing pigeons. References
External links
"Ferumoxytol". Drug Information Portal. U.S. National Library of Medicine.
Anomia can be genetic or caused by damage to various parts of the parietal lobe or the temporal lobe of the brain due to traumatic injury, stroke, or a brain tumor. While anomic aphasia is primarily caused by structural lesions, they may also originate in Alzheimers disease (anomia may be the earliest language deficit in posterior cortical atrophy variant of Alzheimers) or other neurodegenerative diseases.Although the main causes are not specifically known, many researchers have found factors contributing to anomic aphasia. People with damage to the left hemisphere of the brain are more likely to have anomic aphasia. Brocas area, the speech production center in the brain, was linked to being the source for speech execution problems, with the use of functional magnetic resonance imaging (fMRI), now commonly used to study anomic patients. Other experts believe that damage to Wernickes area, which is the speech comprehension area of the brain, is connected to anomia because the patients cannot comprehend the words that they are hearing.Although many experts have believed that damage to Brocas area or Wernickes area are the main causes of anomia, current studies have shown that damage in the left parietal lobe is the cause of anomic aphasia. One study was conducted using a word repetition test as well as fMRI in order to see the highest level of activity as well as where the lesions are in the brain tissue. Fridrikkson, et al. saw that damage to neither Brocas area nor Wernickes area were the sole sources of anomia in the subjects.