Search

High-index dielectric nanoantennas, which provide an interplay between electric and magnetic modes, have been widely used as building blocks for a variety of devices and metasurfaces, both in linear and nonlinear regimes. Here, we investigate hybrid metal-semiconductor nanoantennas, consisting of a multimode silicon nanopillar core coated with a gold layer, that offer an enhanced degree of control over the mode selection and confinement, and emission of light on the nanoscale exploiting high-order electric and magnetic resonances. Cathodoluminescence spectra revealed a multitude of resonant modes supported by the nanoantennas due to hybridization of the Mie resonances of the core and the plasmonic resonances of the shell. Eigenmode analysis revealed the modes that exhibit enhanced field localization at the gold interface, together with high confinement within the nanopillar volume. Consequently, this architecture provides a flexible means of engineering nanoscale components with tailored optical modes and field confinement for a plethora of applications, including sensing, hot-electron photodetection and nanophotonics with cylindrical vector beams.

Introduction: Before implementing a new health care strategy, it is important to assess effectiveness but also to perform an economic evaluation. The goal of the present study was to perform a comparative economic evaluation of a new strategy aimed at using proposed implementation of the Plateletworks guidance (measurement of platelet function) with usual practice (delayed time to surgery) in patients on chronic antiplatelet treatment and scheduled for surgery with neuraxial anaesthesia due to proximal femur fracture. Methods: This is an economic evaluation carried out alongside a randomised controlled clinical trial at four centres in Spain. Patients were randomised to undergo either early platelet function-guided surgery (experimental group) or delayed surgery (control group). As AFFEcT trial results demonstrated significative difference between groups in the primary efficacy endpoint, the median time to surgery, a cost-effectiveness analysis was performed. Direct costs associated with hospitalisation until one-month post-discharge were considered and measured from a hospital perspective. All costs were reported in euros. Analyses were performed on a per protocol basis. Effectiveness outcome measures were the incremental cost and incremental cost per reduction in days to surgery. A deterministic sensitivity analysis was implemented to quantify uncertainty. Results: A total of 156 patients were randomized to the two groups (n = 78 per group). A total of 143 patients were included in the per protocol population (75 and 68 patients in the experimental and control groups, respectively). The median time to surgery was 2.30 days (IQR: 1.53–3.73) in the experimental group and 4.87 days (4.36–5.60) in the control group (a reduction of 2.40 days). Total costs during the 1-month study perioperative period were higher in the delayed surgery group (€18,495.19) than for the early surgery group (€16,497.59). The incremental cost was negative (€1,997.60), a statistically significant difference (P < 0.05). As measured by the reduction in time (days) to surgery, the incremental cost-effectiveness ratio (ICER) for early surgery was negative (777.28€/day). Sensitivity analysis demonstrated consistent cost saving. Conclusion: For patients on chronic antiplatelet treatment scheduled to undergo surgery for proximal femur fracture, an individualised strategy guided by a platelet function testing is a cost-saving and cost-effective strategy. [ABSTRACT FROM AUTHOR]

This work focuses on the photocatalytic production of hydrogen from the photodehydrogenation of ethanol using several gold(I) complexes and gold(0) systems over titanium dioxide (P90 TiO2) as hybrid photocatalysts. The photocatalytic systems are composed of at least one coumarin‐based ligand, which can enhance the photocatalytic activity by its photon‐absorbing capacity due to its chromophore properties. The photocatalytic behavior for hydrogen generation of the studied samples is compared under UV–vis light setting the total gold‐based co‐catalyst loading at 1 wt% onto the TiO2 photocatalysts and when the gold content is maintained at 0.25 wt%. The incorporation of gold co‐catalysts results in an enhancement of hydrogen production up to 2.7 times compared to a conventional Au/TiO2 reference sample. The results show an increase in the total hydrogen production under UV–vis light due to the combined presence of coumarin chromophore, gold‐based co‐catalysts, and gold plasmonic nanoparticles. A deep characterization of the samples from each group is performed by UV–vis spectroscopy, XPS, HRTEM, and HAADF‐STEM, observing the presence of plasmonic gold nanoparticles for sample "AuL1NPs" and the reduction of the gold present in sample "AuL1a," which explains the highest observed hydrogen production rates of this study. [ABSTRACT FROM AUTHOR]

Dry reforming of methane (DRM) was extensively studied on Cu-doped LaNiO3 catalysts. The main findings of this work are as follows: (i) thermal switching of the catalyst phase between the parent perovskite and molecular-level nanocomposite of individual components formed in situ during DRM, (ii) reusability of the catalyst with enhanced activity, and (iii) regeneration of the catalyst phase at a lower temperature than that required for the formation of the parent perovskite. The present investigation provides an extensive analysis and understanding of the DRM reaction using Cu-doped LaNiO3 compared to the result reported by Moradi et al., (Chin. J. Catal., 2012, 33, 797–801) and hence provides new insights into its catalytic activity. Phase-pure LaNi1−xCuxO3 catalysts, specifically LaNi0.8Cu0.2O3, exhibited high catalytic activity towards the DRM reaction (97% CH4 and 99% CO2 conversion with an H2/CO ratio of ∼1.4–0.9). Remarkably, although the initial perovskite phase primarily decomposed into its component phases after DRM, its catalytic activity was barely affected and maintained even after 100 h. The regeneration of the initial perovskite from the disintegrated binary phases via annealing at temperatures even lower than the synthesis temperature together with the amazing retention of activity was very intriguing. The parallel activity of the pristine perovskite and its degraded binary mixtures makes it difficult to identify the actual components responsible for the DRM activity. Accordingly, we have explained the sustained activity of the degraded perovskite catalyst in the context of nanocomposite formation at the molecular level in the reforming atmosphere with the availability of Ni0 and NiO, as revealed by the thoroughly characterized samples in the as-prepared, aged, and regenerated forms. [ABSTRACT FROM AUTHOR]