ABSTRACT
Purpose: Postoperative sleep disturbance, characterized by diminished postoperative sleep quality, is a risk factor for postoperative delirium (POD); however, the association between pre-existing sleep disturbance and POD remains unclear. This study aimed to evaluate the association between preoperative sleep disturbance and POD in elderly patients after non-cardiac surgery. Patients and methods: This retrospective cohort study was conducted at a single center and enrolled 489 elderly patients who underwent surgery between May 1, 2020, and March 31, 2021. Patients were divided into the sleep disorder (SD) and non-sleep disorder (NSD) groups according to the occurrence of one or more symptoms of insomnia within one month or sleep- Numerical Rating Scale (NRS)≥6 before surgery. The primary outcome was the incidence of POD. Propensity score matching analysis was performed between the two groups. Multiple logistic regression analysis was performed to identify the risk factors for POD. Results: In both the unmatched cohort (16.0% vs 6.7%, P=0.003) and the matched cohort (17.0% vs 6.2%, P=0.023), the incidence of POD was higher in the SD group than in the NSD group. In addition, the postoperative sleep quality and the VAS score at postoperative 24 h were significantly lower in the SD group than in the NSD group. Multivariate logistic regression analysis indicated that age (Odds Ratio, 1.13 [95% CI: 1.04-1.23], P=0.003) and preoperative sleep disturbance (Odds Ratio, 3.03 [95% CI: 1.09-9.52], P=0.034) were independent risk factors for the development of POD. Conclusion: The incidence of POD was higher in patients with pre-existing sleep disturbance than those without it. Whether improving sleep quality for preoperative sleep disturbance may help prevent POD remains to be determined.
ABSTRACT
The growing demand for scalable solar-blind image sensors with remarkable photosensitive properties has stimulated the research on more advanced solar-blind photodetector (SBPD) arrays. In this work, the authors demonstrate ultrahigh-performance metal-semiconductor-metal (MSM) SBPDs based on amorphous (a-) Ga2 O3 via a post-annealing process. The post-annealed MSM a-Ga2 O3 SBPDs exhibit superhigh sensitivity of 733 A/W and high response speed of 18 ms, giving a high gain-bandwidth product over 104 at 5 V. The SBPDs also show ultrahigh photo-to-dark current ratio of 3.9 × 107 . Additionally, the PDs demonstrate super-high specific detectivity of 3.9 × 1016 Jones owing to the extremely low noise down to 3.5 fW Hz-1/2 , suggesting high signal-to-noise ratio. Underlying mechanism for such superior photoelectric properties is revealed by Kelvin probe force microscopy and first principles calculation. Furthermore, for the first time, a large-scale, high-uniformity 32 × 32 image sensor array based on the post-annealed a-Ga2 O3 SBPDs is fabricated. Clear image of target object with high contrast can be obtained thanks to the high sensitivity and uniformity of the array. These results demonstrate the feasibility and practicality of the Ga2 O3 PDs for applications in solar-blind imaging, environmental monitoring, artificial intelligence and machine vision.
ABSTRACT
Electrocatalysts with high activities toward multiple electrode reactions are scarce and therefore highly sought. Here, we investigate the electrocatalytic performance of the two-dimensional (2D) Pt5Se4 monolayer toward hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and oxygen reduction reaction (ORR). Our density functional theory calculations show that the Pt5Se4 monolayer can serve as a low-Pt-loading trifunctional electrocatalyst with good kinetic and thermal stabilities. Specifically, the HER performance of the Pt5Se4 basal plane is predicted to be superior to that of 2D layered Pd or Pt dichalcogenides. Even considering the solvent effect, the catalytic OER performance of the Pt5Se4 monolayer is predicted to be comparable to the prevalent OER catalyst-IrO2, while the catalytic ORR performance of the Pt5Se4 monolayer is even higher than the predominating Pt(111) surface. Overall, the Pt5Se4 monolayer can be a promising trifunctional catalyst that exhibits high activities toward all hydrogen and oxygen electrode reactions.
ABSTRACT
Two-dimensional materials with high carrier mobility and tunable magnetism are in high demand for nanoelectronic and spintronic applications. Herein, we predict a novel two-dimensional monolayer KTlO that possesses an indirect band gap of 2.25 eV (based on HSE06 calculations) and high carrier mobility (450 cm2 V-1 s-1 for electrons and 160 cm2 V-1 s-1 for holes) by means of ab initio calculations. The electron mobility can be increased up to 26 280 cm2 V-1 s-1 and 54 150 cm2 V-1 s-1 for bilayer and trilayer KTlO, respectively. The KTlO monolayer has a calculated cleavage energy of 0.56 J m-2, which suggests exfoliation of the bulk material as a viable means for the preparation of mono- and few-layer materials. Remarkably, the KTlO monolayer demonstrates tunable magnetism and half-metallicity with hole doping, which are attributed to the novel Mexican-hat-like bands and van Hove singularities in its electronic structure. Furthermore, monolayer KTlO exhibits moderate optical absorption over the visible light and ultraviolet regions. The band gap value and band characteristics of monolayer KTlO can be substantially manipulated by biaxial and uniaxial strains to meet the requirement of various applications. All these novel properties make monolayer KTlO a promising functional material for future nanoelectronic and spintronic applications.
