No abstract

We demonstrate a novel light trapping configuration based on an array of micro lenses in conjunction with a self aligned array of micro apertures located in a highly reflecting mirror. When locating the light trapping element, that displays strong directional asymmetric transmission, in front of thin film organic photovoltaic cells, an increase in cell absorption is obtained. By recycling reflected photons that otherwise would be lost, thinner films with more beneficial electrical properties can effectively be deployed. The light trapping element enhances the absorption rate of the solar cell and increases the photocurrent by as much as 25%.

The mesenchymal state in cancer is usually associated with poor prognosis due to the metastatic predisposition and the hyper-activated metabolism. Exploiting cell glucose metabolism we propose a new method to detect mesenchymal-like cancer cells. We demonstrate that the uptake of glucose-coated magnetic nanoparticles (MNPs) by mesenchymal-like cells remains constant when the glucose in the medium is increased from low (5.5 mM) to high (25 mM) concentration, while the MNPs uptake by epithelial-like cells is significantly reduced. These findings reveal that the glucose-shell of MNPs plays a major role in recognition of cells with high-metabolic activity. By selectively blocking the glucose transporter 1 channels we showed its involvement in the internalization process of glucose-coated MNPs. Our results suggest that glucose-coated MNPs can be used for metabolic-based assays aimed at detecting cancer cells and that can be used to selectively target cancer cells taking advantage, for instance, of the magnetic-thermotherapy.

Extracellular vesicles (EVs) are nanometric membranous structures secreted from almost every cell and present in biofluids. Because EV composition reflects the state of its parental tissue, EVs possess an enormous diagnostic/prognostic potential to reveal pathophysiological conditions. However, a prerequisite for such usage of EVs is their detailed characterisation, including visualisation which is mainly achieved by atomic force microscopy (AFM) and electron microscopy (EM). Here we summarise the EV preparation protocols for AFM and EM bringing out the main challenges in the imaging of EVs, both in their natural environment as biofluid constituents and in a saline solution after EV isolation. In addition, we discuss approaches for EV imaging and identify the potential benefits and disadvantages when different AFM and EM methods are applied, including numerous factors that influence the morphological characterisation, standardisation, or formation of artefacts. We also demonstrate the effects of some of these factors by using cerebrospinal fluid as an example of human biofluid with a simpler composition. Here presented comparison of approaches to EV imaging should help to estimate the current state in morphology research of EVs from human biofluids and to identify the most efficient pathways towards the standardisation of sample preparation and microscopy modes.

In this paper we report on the fabrication and testing of a novel concept of sealed electrochemical microcell for in situ soft X-ray microspectroscopy in transmission, dedicated for nonvacuum compatible electrolytes. The microcell, fabricated using ultraviolet lithography, at variance with previous versions of electrochemical wet cells, that featured an optical window glued on top of the electrode system and a very limited electrolyte volume, the device presented here is a single solid block based around a microfabricated channel with fixed optical windows and apt for microfluidic work. Moreover, this cell allows to employ an advanced electrodic geometry developed in our group - so far used only in open electrochemical cells for work with vacuum-compatible electrolytes - also with low-vapor pressure liquids, possibly saturated with the required gases. The cell optimal electrode design allows three-electrode electrochemical control typical of traditional electrochemical experiments. The first electrochemical experiments with this new cell explore the electrochemical growth of a Co-polypyrrole, a composite electrocatalyst material with promising performance to replace the expensive Pt catalyst in fuel-cell oxygen electrodes. Morphological and chemical-state distributions of Co codeposited with polypyrrole has been followed as a function of time and position, yielding unprecedented information on the processes relevant to the synthesis of this catalyst.