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Demantoid from Kerman Province in south-east Iran was investigated using microscopy, spectroscopy (optical absorption, FTIR and Raman), chemical analysis (EDXRF and LA-ICP-TOF-MS) and magnetic susceptibility measurements. The samples were transparent to semi-transparent and commonly contained acicular chrysotile inclusions. Their spectroscopic and chemical properties were consistent with demantoid from serpentinite host rock. The samples ranged from yellowish green to deep green, depending on Cr and Fe content. These two elements are also largely responsible for the material's paramagnetic susceptibility. Our samples contained relatively high concentrations of the trace elements Cr, Ge, Ni and Co. Comparison with available chemical data on serpentinite-hosted demantoid from the literature suggests that Iranian demantoid can be separated from stones of other localities. [ABSTRACT FROM AUTHOR]

Magnetotactic bacteria produce magnetite nanoparticles called magnetosomes at ambient conditions via a protein‐stabilized transient amorphous precursor to obtain precise control over particle size and morphology. In a bioinspired approach, such biomineralization processes are emulated, mimicking proteins involved in magnetosome formation using the positively charged analog poly‐L‐arginine. While the additive is expensive, it remains elusive whether the change in magnetite formation mechanism arises solely from the polymer's cationic nature. This study uses different mass‐produced and sustainably sourced polycations to induce the biomineralization‐reminiscent formation of magnetite nanoparticles. These findings present how to achieve control over nanoparticle size (from 10 to 159 nm) and morphology (compact and sub‐structured) as well as magnetic properties (superparamagnetic, stable‐single‐domain, vortex state) at ambient temperature and pressure using these additives. Furthermore, the formation of large nanoparticles with the addition of poly(diallyldimethylammonium chloride) (PDADMAC) at low alkalinity highlights how magnetotactic bacteria may produce magnetite nanoparticles under similar conditions. Confirming the polycations' ability to electrostatic stabilize amorphous ferrihydrite, it is anticipated that parametric in vitro studies on polymer properties will provide valuable insights into magnetite biomineralization and aid in rationally designing magnetic nanomaterials. [ABSTRACT FROM AUTHOR]

Magnetic nanomaterials find increasing application as separation agents to rapidly isolate target compounds from complex biological media (i.e., blood purification). The responsiveness of the used materials to external magnetic fields (i.e., their saturation magnetization) is one of the most critical parameters for a fast and thorough separation. In the present study, magnetite (Fe3O4) and non-oxidic cementite (Fe3C) based carbon-coated nanomagnets are characterized in detail and compared regarding their separation behavior from human whole blood. A quantification approach for iron-based nanomaterials in biological samples with strong matrix effects (here, salts in blood) based on platinum spiking is shown. Both materials are functionalized with polyethyleneglycol (PEG) to improve cytocompatibility (confirmed by cell toxicity tests) and dispersability. The separation performance is tested in two setups, namely under stationary and different flow-conditions using fresh human blood. The results reveal a superior separation behavior of the cementite based nanomagnets and strongly suggest the use of nanomaterials with high saturation magnetizations for magnetic retention under common blood flow conditions such as in veins. [ABSTRACT FROM AUTHOR]

An integrated structural, anisotropy of magnetic susceptibility (AMS) and paleomagnetic study was carried out on Plio-Pleistocene sedimentary basins in eastern Sicily. These basins belong to three main tectonic domains: the Tyrrhenian hinterland domain, the Catania foredeep domain, and the Hyblean foreland domain. We sampled 329 oriented samples from 25 sites in selected areas from the different tectonic domains. The AMS is typical for weakly deformed sediments, with a magnetic foliation sub-parallel to the bedding plane, and a well-defined magnetic lineation. The orientation of the magnetic lineation is strongly controlled by the main tectonic deformation recorded in the basins. Structural and AMS data define a transition from NW–SE extension in the Tyrrhenian hinterland domain, to E–W compression in the Catania foredeep domain, to E–W extension in the Hyblean foreland domain, respectively. Reliable paleomagnetic results have been obtained in 12 out of 25 sampled sites. Data show that no significant rotations occurred in any of the studied basins at least since the middle Pleistocene. These results allow us to define an upper limit to the large rotations about vertical axes that have been previously found in the Calabria and Sicily regions. [Copyright &y& Elsevier]

High magnetic responsiveness is critical for nanomagnets in biomedicine, and fast and complete separation is essential for blood purification or targeted drug delivery, to diminish potential risks. However, studies on the collection efficiency of iron‐based nanoparticles are rare. On page 4888, W. J. Stark and co‐workers present a new quantification approach based on platinum doping of magnetite and carbon‐coated cementite nanoparticles. Their findings show that a good separation efficiency from human whole blood calls for nanomaterials with high saturation magnetizations. [ABSTRACT FROM AUTHOR]