A smartphone-based petrographic microscope.

Photomicrographs of thin sections provide a swift and efficient means of sharing information for consultation, education, documentation and publication within the Geosciences and related areas. In general terms, the main way to capture digital microscopic images involves the use of a mounted camera unit on a high-end costly benchtop microscope. However, freehand methods to capture microscope-scale images using a smartphone, as well as smartphone adapters that can be attached to a microscope have emerged during recent years. This paper presents the design features of a costless system able to obtain photomicrographs without requiring a conventional microscope. The imaging device is comprised of a mini-objective lens attached to a smartphone and a structure that allows it to focus as well as to rotate the stage and to insert/remove a polarized sheet. The quality and magnification of the images attainable from the new design is comparable to the images normally obtained by a conventional petrographic microscope using a ×4 objective and a ×10 ocular (total magnification ×40).

Self-assembled multifunctional Fe/MgO nanospheres for magnetic resonance imaging and hyperthermia.

A one-step process for the production of nanoparticles presenting advanced magnetic properties can be achieved using vapor condensation. In this article, we report on the fabrication of Fe particles covered by a uniform MgO epitaxial shell. MgO has a lower surface energy than Fe, which results in a core-shell crystal formation. The particles satisfy a few of technical requirements for the practical use in real clinics, such as a high biocompatibility in living cells in-vitro, an injection through blood vessels without any clothing problems in murine model, a high absorption rate for magnetic hyperthermia at small particle concentration, and the potential to be used as contrast agent in the field of diagnostic magnetic imaging. They are also able to be used in drug delivery and magnetic-activated cell sorting. FROM THE CLINICAL EDITOR: In this paper, the authors report on the synthesis of Fe particles covered by a uniform MgO epitaxial shell resulting in a core-shell crystal formation. The particles are proven to be useful as contrast agents for magnetic resonance imaging and have the potential to be useful as heating mediators for cancer therapy through hyperthermia. They also might be used in drug delivery and magnetic-activated cell sorting.

Ultraporous single phase iron oxide-silica nanostructured aerogels from ferrous precursors.

Monoliths of iron oxide-silica aerogel nanocomposites have been synthesized using a novel synthesis route which consists of impregnating silica wet gels with anhydrous iron(II) precursors followed by ethanol supercritical drying of the gels. The process yields aerogels exhibiting high porosity, large surface areas (approximately 900 m2/g), rather low densities (approximately 0.6 g/cm3), and a homogeneous distribution of single-phase maghemite, gamma-Fe2O3, nanoparticles with average sizes in the 7-8 nm range. Remarkably, the gamma-Fe2O3 nanoparticles are obtained in the as-dried state without the need of postannealing. The nanoparticles are mostly superparamagnetic at room temperature but become blocked in a ferrimagnetic state at lower temperatures.