We present a new approach to prepare Transmission Electron Microscopy (TEM) nanowire (NW) samples that addresses the core drawbacks of conventional techniques, which are based on mechanical polishing. The proposed method is time efficient and uses XeF2 isotropic and selective dry etching of Si to remove the host substrate from the NWs, after their embedding into a poly(methyl-methacrylate) (PMMA) matrix. Scanning electron microscopy (SEM) data suggest that NWs were grown through the gaps between the parasitic layer islands and that the stems are in direct contact with the Si substrate. This technique does not adversely affect the NWs and offers a convenient means of transferring the GaAs NWs onto other surfaces for post-process TEM analysis. It also offers excellent potential to facilitate their integration into device fabrication via a bottom-up approach, using the PMMA layer as a transfer medium.

A growing number of studies focusing on the developmental origin of health and disease hypothesis have identified links among early nutrition, epigenetic processes and diseases also in later life. Different epigenetic mechanisms are elicited by dietary factors in early critical developmental ages that are able to affect the susceptibility to several diseases in adulthood. The studies here reviewed suggest that maternal and neonatal diet may have long-lasting effects in the development of non-communicable chronic adulthood diseases, in particular the components of the so-called metabolic syndrome, such as insulin resistance, type 2 diabetes, obesity, dyslipidaemia, hypertension, and CVD. Both maternal under- and over-nutrition may regulate the expression of genes involved in lipid and carbohydrate metabolism. Early postnatal nutrition may also represent a vital determinant of adult health by making an impact on the development and function of gut microbiota. An inadequate gut microbiota composition and function in early life seems to account for the deviant programming of later immunity and overall health status. In this regard probiotics, which have the potential to restore the intestinal microbiota balance, may be effective in preventing the development of chronic immune-mediated diseases. More recently, the epigenetic mechanisms elicited by probiotics through the production of SCFA are hypothesised to be the key to understand how they mediate their numerous health-promoting effects from the gut to the peripheral tissues.

Practical design of high-voltage SiC Schottky rectifiers requires the understanding of the influence of the epitaxial dopant concentration on the reverse and forward characteristics. This work analyzes the correlation between the dopant concentration and the I-V characteristics of Schottky diodes for a critical concentration range where the leakage current variations are more evident. The details of how high temperatures affect the properties of junctions have been carefully described to obtain further improvement in the future by proper device optimization. Dopant concentration of about 1.2 × 1016 cm-3 gives the best results in reverse characteristics without great losses in forward currents.

The growth rate of 4H-SiC epitaxial layer has been increased by a factor 19 (up to 112 μm/h) with respect to the standard process with the introduction of HCl in the deposition chamber. The epitaxial layers grown with the addition of HCl have been characterized by electrical, optical and structural characterization methods. The effects of different deposition parameters on the epitaxial growth process have been described in detail. This process can be very promising for high power devices with a breakdown voltage of 10 kV.