Homogeneous nanocomposite silica films uniformly doped with size-selected gold nanoparticles (AuNPs) have been prepared by a combined use of colloidal chemistry and the sol-gel process. For this purpose, stable thiol-functionalized AuNPs (DDT-AuNPs) were first synthesized by a two-phase aqueous/organic system and, subsequently, dispersed in an acid-catalysed sol-gel silica solution. The microstructural morphology of the samples was investigated by x-ray diffraction and field emission scanning electron microscopy. X-ray photoelectron spectroscopy (XPS) and UV-vis optical spectrophotometry were instead employed to investigate the elemental chemical behaviour and the evolution of the surface plasmon resonance (SPR) band of the AuNPs from their synthesis up to the formation of the Au-doped silica films. The results show that the size, shape and crystalline domains of the AuNPs remain unchanged during the entire preparation process, indicating that their aggregation or decomposition was prevented. XPS results show that the DDT-AuNPs lose the capping shells and oxidize themselves when dispersed in acid-catalysed sol-gel solutions, and that bare AuNPs are embedded in the SiO(2) films. A large broadening of the SPR band, observed for systems with DDT-AuNPs, suggests the presence of interface effects which cause a surface electron density lowering. Thiol chain detachment from the AuNPs determines an increase of the SPR peak intensity while the oxidation of the Au surfaces causes a red shift of its position. The latter is no longer observed in doped films, suggesting that no interfacial effects between bare AuNPs and the host medium are present.

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Objective To explore the effect of frailty, alone and in combination with post‐operative delirium (POD), on the risk of poor function at discharge in patients with hip fracture (HF). Methods This is a prospective cohort study of patients with HF admitted to an Orthogeriatric Unit (OGU) between October 1, 2011 and March 15, 2019. POD was assessed using the 4AT and the Diagnostic and Statistical Manual of Mental Disorders (DSM) 5‐edition criteria. A 22‐items Frailty Index (FI) was created using the data collected on admission. The outcome measure was the Cumulated Ambulation Score (CAS) score at discharge. A log‐binomial regression model was used to assess the effect of frailty and POD on CAS. Results A total of 988 patients (median age = 84.9 years, Interquartile range = 80.6‐89.2) were included: 360 patients (36.4%) were frail and 411 (42%) developed POD. Poor functional status at discharge (CAS score ≤2) was more common in frail than non‐frail patients (68.3% vs. 53.8%, p < 0.001) In a regression adjusted for confounders, frailty alone (Relative Risk, RR = 1.33, 95% Confidence Intervals, CI = 1.14–1.55) and POD alone (RR 1.38, 95% CI = 1.2–1.59) were associated with poor functional status at discharge; when combined, frailty and POD had an interaction, yielding a mild increase in the risk of poor outcome (RR 1.47, 95% CI = 1.28–1.69). Conclusions In older patients undergoing HF surgery, frailty, POD and their combination, are associated with poor functional status at discharge.

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