In this work, a theoretical study of the relationship between the electronic structure and the activity of the P2X7R receptor from 2-hydroxy-1,4-naphthoquinone derivatives, using the KPG method, was performed. The electronic structure of the molecules was calculated at level B3LYP / 6-31G (d, p) with full geometry optimization. A statistically significant equation was obtained by relating the variation of biological activity with the variation of a set of indices of local atomic reactivity. Based on the analysis of the results, a two-dimensional pharmacophore was proposed.

The sensor 1-(4-mercaptophenyl)-2,4,6-triphenylpyridinium perchlorate compound was vibrationally characterized using Raman and the Surface-Enhanced Raman techniques, SERS and Shell-Isolated Nanoparticles-Enhanced Raman Spectroscopy (SHINERS). The Raman spectrum was analyzed and the band assignment was supported using DFT data at the B3LYP/6-31G(d) level. SERS data allowed infer about the orientation of the analyte on the naked Ag surface. EHT calculations for an Ag/analyte model represent well the SERS spectrum supporting the Ag-S bond formation. The SHINERS spectrum was obtained by using Ag@SiO 2 nanoparticles prepared at two different time of the SiO 2 coating process. The most intense SHINERS spectral signals of the compound (100 nM) were obtained after 20 minutes of the Ag@SiO 2 formation. No charge-transfer was concluded from the SHINERS experiments.

This work concerns the study of colors and dyes identified on archaeological textiles from the Atacama Desert. The different garments and ornaments come from the excavation of two important pre-Columbian cemeteries of the Tarapacá region: Tarapacá-40 attributed to the Formative period (1100 BC - 660 AD) and Pica-8 to the Late Intermediate period (900 - 1450 AD). For the first time, a multi-analytical approach with non-invasive techniques using Fiber Optics Reflectance Spectroscopy (FORS), Attenuated Total Reflection Infrared Spectroscopy (FT-IR) and Surface-enhanced Raman Scattering (SERS) were applied on samples of less than 2 cm of length for physicochemical characterization of the raw materials and the dyes employed in the textile production of northern Chile. The fibers are from animal origin. Blue, green, and yellow are identified as indigo, but we cannot discard a mixture with other dyes to vary hue and shade; while carminic acid and alizarin - to a lesser extent - are found on red, orange and brown samples. This research provides new elements for the discussion about the textile technology developed in this desertic region, its changes and continuities along with the history. Our results are compared to recent findings on neighbouring regions from northern Chile, to improve the current knowledge and discuss the existence of dyeing textile cultural traditions.