Anion exchange has been recognized as one of the most effective approaches for mediating the spontaneous formation of mixed-halide perovskite nanocrystals (MHPs) with tunable optical properties and color quality. However, the difference in the diffusion capability of halides, specifically between bromide and iodide species, into MHPs makes these materials prone to halide deficiency, which deteriorates their structural integrity and stability. In this work, we studied the surface passivation and composition engineering by introducing a dinuclear calcium-iodide scorpionate complex (CaISC) dispersed into different organic solvents such as chloroform, dichloromethane, 1,2-dichloroethane, and acetonitrile, which favor or hinder the I-for-Br exchange process between this ligand and native CsPbBr3 perovskite nanocrystals (PNCs). By analyzing the CaISC content and the nature of the solvent, we are able to efficiently promote halide exchange, also generating an intermediate mononuclear Ca2+ complex, favoring Ca2+ doping and the diffusion of a high density of iodide species for triggering Pb2+ and halide defect compensation. From this strategy, suitable CaISC-capped CsPbBr3-xIx PNCs active layers were prepared for the fabrication of efficient down-light converters, with operational stability up to 480 h. This contribution offers an alternative for the processing of stable multicolor PNCs with facile modulation of their photophysical properties, making them adequate for the fabrication of future LED technologies.
This study explored the biological durability of Pinus radiata wood treated with copper nanoparticles (CuNPs) and a commercial micronized copper (M) formulation. The internal structural integrity of the wood was evaluated using micro-computed tomography. Sapwood specimens were pressure-impregnated with CuNP (0.31% w/w) or M (0.56% w/w), achieving average copper retentions of 0.98 and 1.05 kg m(-3), respectively. Biological resistance was assessed through standardized soil-block decay tests using Gloeophyllum trabeum, Coniophora puteana, Trametes versicolor, and Irpex lacteus, and an 8-week no-choice subterranean termite assay with Reticulitermes flavipes. After 12 weeks of fungal exposure, treated specimens exhibited markedly lower mass losses (<4.5% for CuNP and <1% for M) than untreated controls (11-25%). Chemical composition analyses confirmed the reduced degradation of cellulose, hemicellulose, and lignin in the treated wood. Termite tests showed mass losses of 9.0% for M and 5.7% for CuNP; notably, CuNP-treated blocks caused complete termite mortality. High-resolution micro-computed tomography provided 3D evidence of preserved microstructures and revealed distinct preservative distribution patterns associated with each formulation. Overall, this study provides an integrated structural and biological evaluation demonstrating that both CuNP and M treatments enhance the durability of P. radiata, with CuNP offering promising performance, supported by micro-CT insights.
BACKGROUND:Dietitians-nutritionists (DNs) play a key role in intensive care units (ICUs), yet their scope of practice varies across settings. This study aimed to describe the professional practices of DNs working in ICUs in Latin America and to identify factors associated with their level of professional activity. METHODS:A cross-sectional study was conducted using an online survey targeting DNs working in ICUs across 18 Latin American countries. The survey included two questionnaires: one assessing professional functions and responsibilities, and another evaluating practices, dynamics, and resources for nutritional care. RESULTS:A total of 223 responses were obtained, mainly from Argentina, Chile, Colombia, Peru, and Mexico. Respondents reported a median of 10 years of professional experience (interquartile range: 6-16). Most worked in high-complexity public hospitals (141 [63.2%]) and reported ≥40 h workweeks (144 [64.6%]); 137 (61.4%) held postgraduate degrees. Systematic participation in nutritional assessment, intervention, and monitoring was reported by 165 (74.0%), 183 (82.1%), and 168 (75.3%) respondents, respectively. Only 97 (43.5%) were authorized to prescribe nutritional therapy, with institutional policies identified as the main barrier. Academic involvement was limited, with 91 (41.7%) occasionally participating in teaching and 93 (42.1%) in research. The NRS-2002 was the most commonly used screening tool; only 16 (7.2%) reported access to indirect calorimetry, and 120 (53.8%) assessed muscle mass, mainly by anthropometry CONCLUSIONS: DNs in Latin America play an active role in ICU nutritional care but face important limitations in clinical autonomy, access to diagnostic tools, and academic participation.
The quality of grape juice (Vitis vinifera L. cv. Pais) obtained with a prototype steam extractor designed to reduce juice dilution by separate collection of condensates was evaluated and compared with conventional steam extracted and hand-pressed juice. The prototype extractor consistently outperformed the conventional system by better preserving the chemical quality of the fruit and ensuring greater stability during storage, producing grape juices with superior physicochemical characteristics, including total soluble solids and titratable acidity similar to hand-pressed juice. While initial concentrations of total phenolics were equal for both steam extracted juices, total anthocyanins, total flavonoids, and antioxidant capacity were substantially higher than in both conventional steam extracted and hand-pressed juice. During storage, the prototype-extracted juice showed minimal changes in key quality parameters from 1 to 3 months. Overall, this study demonstrates that the steam extractor design reduces juice dilution while improving stability and functional quality of the resulting grape juice.
PurposeThis paper aims to evaluate and compare the wave reflection performance of two double-permeable-wall absorbers differing only in front geometry: a flat wall and a V-shaped wall. This study seeks to quantify how front geometry influences the reflection coefficient (KR) under different wave conditions while maintaining constant porous-medium parameters, thereby identifying configurations that enhance wave energy dissipation in coastal protection structures.Design/methodology/approachThree-dimensional CFD simulations were conducted in OpenFOAM using the interIsoFoam solver to model fluid-porous-structure interaction. Both absorber geometries were analyzed under six regular wave conditions, varying wave period. Porous walls were represented through Darcy-Forchheimer formulations with constant permeability and porosity. Free-surface elevation data were extracted using ParaView and Python; the signals were then postprocessed in MATLAB, and the reflection coefficient was computed using the Mansard and Funke three-point wave separation method.FindingsThe results of this study indicate that the V-shaped front consistently achieves lower reflection coefficients than the flat front under all analyzed conditions. The improvement is attributed to enhanced flow deflection, fragmentation and dissipation of wave energy. However, as the wave period increases, the V-shape advantage decreases, with both configurations converging toward similar KR values. Velocity and vorticity field analysis revealed stronger and more persistent vortical structures in the flat-wall configuration.Originality/valueThis study provides a novel comparative assessment of double-porous-wall absorbers with identical porous properties but distinct geometries in three dimensions. The findings of this study highlight the importance of geometric design in optimizing passive wave absorbers and demonstrate that V-shaped configurations can improve energy dissipation efficiency, guiding future developments of coastal protection structures.
