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Perovskite solar cells are considered to be one of the most promising solar cell designs in terms of photovoltaic efficiency. However, their practical deployment is strongly affected by their short lifetimes, mostly caused by environmental conditions and UV degradation. In this contribution, we present a metasurface made of silver nanoparticles used as a UV filter on a perovskite solar cell. The UV-blocking layer was fabricated and morphologically and compositionally analyzed. Its optical response, in terms of optical transmission, was also experimentally measured. These results were compared with simulations made through the use of a well-proven computational electromagnetism model. After analyzing the discrepancies between the experimental and simulated results and checking those obtained from electron beam microscopy and electron dispersion spectroscopy, we could see that a residue from fabrication, sodium citrate, strongly modified the optical response of the system, generating a redshift of about 50 nm. Then, we proposed and simulated the optical behavior of core-shell nanoparticles made of silver and silica. The calculated spectral absorption at the active perovskite layer shows how the appropriate selection of the geometrical parameters of these core-shell particles is able to tune the absorption at the active layer by removing a significant portion of the UV band and reducing the absorption of the active layer from 90% to 5% at a resonance wavelength of 403 nm.

Objective: social networks (SN) including Instagram have increased in popularity. However, SN-mediated content may influence eating behaviors in a negative way. This study analyzed whether Instagram content claimed as "healthy" complies with nutritional guidelines., Methods: recipes posted in French on Instagram with the caption #healthy or similar ones were analyzed, once from February to May 2023 and again in April 2024. Health authorities' guidelines and food pyramid inclusion criteria were used for the quantitative and qualitative analysis, respectively. Recipes were then classified as balanced, partially unbalanced or unbalanced, with the two subgroups "restrictive" and "excessive", and according to the main protein source., Results: we coded a total of 114 courses (2 datasets of 57 courses each). Among these, 3 were classified as balanced main courses, 45 as partially unbalanced main courses and 66 as unbalanced main courses (21 were deemed as restrictive, 21 as excessive and 24 were otherwise inadequate), with a majority of hypocaloric courses. Approximately half of the recipes were vegetarian or vegan., Discussion: these results suggest that food recipes published on Instagram as #healthy may, at times, be far from nutritional guidelines and could rather promote unbalanced eating patterns. This suggest that food-related content on SN might be insufficiently moderated and that recipes referenced as #healthy should perhaps be accompanied by warnings and preventive measures. This observation, in addition to other detrimental behaviors displayed on SN (e.g. extreme physical activity or body image pressure) may contribute to the increased incidence of eating disorders (ED) associated with problematic SN use. Alerts on this risk and accessible tools for the prevention and early detection of ED risk in SN users are urgently needed., Competing Interests: Declaration of competing interest None declared., (Copyright © 2024 Elsevier Ltd. All rights reserved.)