RESUMEN
A method for cross-sectional doping of individual Si/SiO2 core/shell nanowires (NWs) is presented. P and B atoms are laterally implanted at different depths in the Si core. The healing of the implantation-related damage together with the electrical activation of the dopants takes place via solid phase epitaxy driven by millisecond-range flash lamp annealing. Electrical measurements through a bevel formed along the NW enabled us to demonstrate the concurrent formation of n- and p-type regions in individual Si/SiO2 core/shell NWs. These results might pave the way for ion beam doping of nanostructured semiconductors produced by using either top-down or bottom-up approaches.
RESUMEN
Signaling through the interleukin-4/interleukin-13 (IL-4/IL-13) receptor complex is a crucial mechanism in the development of bronchial asthma and chronic obstructive pulmonary disease (COPD). In bronchial epithelial cells, this signaling pathway leads to changes in the expression levels of several genes that are possibly involved in protection against and/or pathogenesis of these diseases. The expression of pendrin (SLC26A4), a candidate for the latter category, is upregulated by IL-4/IL-13 and leads to overproduction of mucus and increased viscosity of the airway surface liquid (ASL). Therefore, elucidating the transcriptional regulation of pendrin could aid in the development of new pharmacological leads for asthma and/or COPD therapy. Here we show that IL-4/IL-13 significantly increased human pendrin promoter activity in HEK-Blue cells but not in STAT6-deficient HEK293 Phoenix cells; that mutation of the STAT6 binding site (N(4) GAS motif) rendered the promoter insensitive to IL-4/IL-13; and that addition of the N(4) GAS motif to an IL-4/IL-13-unresponsive sequence of the human pendrin promoter conferred sensitivity to both ILs.