Results 1 to 10 of about 1,707 (128)
Controlled cobalt doping in biogenic magnetite nanoparticles. [PDF]
J R Soc Interface, 2013 Cobalt-doped magnetite (Co x Fe 3 − x O 4 ) nanoparticles have been produced through the microbial reduction of cobalt–iron oxyhydroxide by the bacterium Geobacter sulfurreducens
Byrne JM +10 more
europepmc +6 more sources
Big discovery for biogenic magnetite. [PDF]
Proc Natl Acad Sci U S A, 2008 One of the most significant characteristics of the Anthropocene (the present age of geologic time) is the rate at which humans are perturbing the global carbon cycle. The potency of carbon dioxide and methane as greenhouse gases and their effects on Earth's temperature balance is well established (1), and the myriad of climate and ecological changes ...
Lippert PC.
europepmc +4 more sources
Biogenic magnetite in the nematode caenorhabditis elegans. [PDF]
Proc Biol Sci, 2004 The nematode Caenorhabditis elegans is widely used as a model system in biological research. Recently, examination of the production of heat-shock proteins in this organism in response to mobile phone-type electromagnetic field exposure produced the most robust demonstration to date of a non-thermal, deleterious biological effect.
Cranfield CG +5 more
europepmc +4 more sources
Gigantism in unique biogenic magnetite at the Paleocene-Eocene Thermal Maximum. [PDF]
Proc Natl Acad Sci U S A, 2008 We report the discovery of exceptionally large biogenic magnetite crystals in clay-rich sediments spanning the Paleocene–Eocene Thermal Maximum (PETM) in a borehole at Ancora, NJ. Aside from previously described abundant bacterial magnetofossils, electron microscopy reveals novel spearhead-like and spindle-like magnetite up to 4 μm long and ...
Schumann D +13 more
europepmc +5 more sources
Tricks of Nature From the Ancient Earth and Early Mars: Chemical Gardens Generate Biomorphs With High Preservation Potential. [PDF]
GeobiologyABSTRACT Observations of morphology are commonly used to evaluate the biogenicity of terrestrial microfossils and could constitute a crucial line of evidence for extraterrestrial life‐detection missions in the future. However, evaluating the origin of morphological features in the rock record can be problematic because naturally occurring abiotic ...
Hirsch S +3 more
europepmc +2 more sources
Membrane Vesicle Formation Removes Iron Sulfide Mineral Crusts From the Cell Surface of Growing Sulfate-Reducing Bacteria. [PDF]
GeobiologyABSTRACT Sulfate‐reducing bacteria (SRB) drive the process of sulfate reduction in low‐temperature sedimentary environments. Through the production of sulfide, they promote the formation of iron‐sulfide (Fe‐S) minerals when Fe(II) is available. The negative charge of the cell surface of bacteria can promote the binding of Fe(II), leading to the ...
Brokaw C, Boyd P, Picard A.
europepmc +2 more sources
Looking for biogenic magnetite in brain ferritin using NMR relaxometry
NMR in Biomedicine, 2005 AbstractMammalian cellular iron is stored inside the multisubunit protein ferritin, normally taking the structure of a ferrihydrite‐like mineral core. It has been suggested that biogenic magnetite, which has been detected in the brain and may be related to neurodegenerative diseases such as Alzheimer's and Parkinson's diseases, could initially form in ...
Yves Gossuin +2 more
exaly +4 more sources
Reductive dissolution of biogenic magnetite [PDF]
Earth, Planets and Space, 2020 Abstract Reductive dissolution of magnetite is known to occur below the Fe-redox boundary in sediments. In this study, detailed processes associated with biogenic magnetite dissolution are documented. A sediment core from the Japan Sea was used for this purpose, in which reductive dissolution of magnetic minerals is known to start at ...
openaire +2 more sources
Manganese in biogenic magnetite crystals from magnetotactic bacteria [PDF]
FEMS Microbiology Letters, 2009 Magnetotactic bacteria produce either magnetite (Fe(3)O(4)) or greigite (Fe(3)S(4)) crystals in cytoplasmic organelles called magnetosomes. Whereas greigite magnetosomes can contain up to 10 atom% copper, magnetite produced by magnetotactic bacteria was considered chemically pure for a long time and this characteristic was used to distinguish between ...
Carolina N, Keim +2 more
openaire +2 more sources
Magnetite in the human body: Biogenic vs. anthropogenic [PDF]
Proceedings of the National Academy of Sciences, 2016 Magnetite is an iron-oxide mineral that occurs naturally on Earth. Because it is also an important component of many anthropogenic materials (e.g., coal fly ash) and synthetic products (e.g., black toner powders), magnetite can be released to the environment through human activities (1). In PNAS, Maher et al.
openaire +3 more sources