Low doses of uranium and osteoclastic bone resorption: key reciprocal effects evidenced using new in vitro biomimetic models of bone matrix.

Uranium is widely spread in the environment due to its natural and anthropogenic occurrences, hence the importance of understanding its impact on human health. The skeleton is the main site of long-term accumulation of this actinide. However, interactions of this metal with biological processes involving the mineralized extracellular matrix and bone cells are still poorly understood.

Tailored Microstructured Hyperpolarizing Matrices for Optimal Magnetic Resonance Imaging.

Tailoring the physical features and the porous network architecture of silica-based hyperpolarizing solids containing TEMPO radicals, known as HYPSO (hybrid polarizing solids), enabled unprecedented performance of dissolution dynamic nuclear polarization (d-DNP). High polarization values up to P( H)=99 % were reached for samples impregnated with a mixture of H O/D O and loaded in a 6.7 T polarizer at temperatures around 1.

GaAs nanowires with oxidation-proof arsenic capping for the growth of an epitaxial shell.

We propose an arsenic-capping/decapping method, allowing the growth of an epitaxial shell around the GaAs nanowire (NW) core which is exposed to an ambient atmosphere, and without the introduction of impurities. Self-catalyzed GaAs NW arrays were firstly grown on Si(111) substrates by solid-source molecular beam epitaxy. Aiming for protecting the active surface of the GaAs NW core, the arsenic-capping/decapping method has been applied.

GaAs Core/SrTiO3 Shell Nanowires Grown by Molecular Beam Epitaxy.

We have studied the growth of a SrTiO3 shell on self-catalyzed GaAs nanowires grown by vapor-liquid-solid assisted molecular beam epitaxy on Si(111) substrates. To control the growth of the SrTiO3 shell, the GaAs nanowires were protected using an arsenic capping/decapping procedure in order to prevent uncontrolled oxidation and/or contamination of the nanowire facets. Reflection high energy electron diffraction, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy were performed to determine the structural, chemical, and morphological properties of the heterostructured nanowires.

AlN hollow-nanofilaments by electrospinning.

We present for the first time an original method to elaborate AlN nanofilaments (NFs) by using a preceramic-based electrospinning process. Initially, an Al-containing precursor (poly(ethylimino)alane) is mixed with an organic spinnable polymer to be electrospun and generate polymeric filaments with a homogeneous diameter. A ceramization step at 1000 °C under ammonia and a crystallization step at 1400 °C under nitrogen are performed to get the final product made of AlN NFs with a diameter ranging from 150 to 200 nm.