RESUMO
Promoting the hydrogen oxidation reaction (HOR) activity and poisoning tolerance of electrocatalysts is crucial for the large-scale application of hydrogen-oxygen fuel cell. However, it is severely hindered by the scaling relations among different intermediates. Herein, lattice-contracted Pt-Rh in ultrasmall ternary L12-(Pt0.9Rh0.1)3V intermetallic nanoparticles (~2.2 nm) were fabricated to promote the HOR performances through an oxides self-confined growth strategy. The prepared (Pt0.9Rh0.1)3V displayed 5.5/3.7 times promotion in HOR mass/specific activity than Pt/C in pure H2 and dramatically limited activity attenuation in 1000 ppm CO/H2 mixture. In-situ Raman spectra tracked the superior anti-CO* capability as a result of compressive strained Pt, and the adsorption of oxygen-containing species was promoted due to the dual-functional effect. Further assisted by density functional theory calculations, both the adsorption of H* and CO* on (Pt0.9Rh0.1)3V were reduced compared with that of Pt due to lattice contraction, while the adsorption of OH* was enhanced by introducing oxyphilic Rh sites. This work provides an effective tactic to stimulate the electrocatalytic performances by optimizing the adsorption of different intermediates severally.
RESUMO
Background: During the perioperative period, empiric antibiotic escalation therapy is not uncommon, leading to longer postoperative hospital stay and higher medical expenses. However, few systematic studies have investigated this issue. In this case-control study, we explored the factors affecting empiric antibiotic escalation therapy after minimally invasive lung surgery during hospitalization, with the aim to enhance recovery after surgery and rational use of antibiotics. Methods: The data of patients who underwent minimally invasive lung surgery at our center from January 2019 to December 2020 were collected from the hospital information system (HIS). A total of 1,360 cases were identified based on the inclusion and exclusion criteria. These patients were divided into 2 groups: group A (n=825), in which patients did not receive antibiotic escalation therapy after surgery; and group B (n=535), in which patients received empiric antibiotic escalation therapy after surgery. A logistic regression model was used to analyze the influencing factors of empiric antibiotherapy escalation during postoperative hospitalization. Results: Compared with group A, group B had significantly longer postoperative hospital stay (5.05±2.78 vs. 4.49±2.24 days, P<0.001) and slightly higher average total hospitalization costs (74,080.85±23,796.51 vs. 71,798.09±21,307.26 yuan, P=0.067). Multivariate analysis showed that the statistically significant factors included history of secondary lung surgery [odds ratio (OR): 3.267; 95% confidence interval (CI): 1.305-8.178; P=0.011], preoperative hemoglobin A1c (HbA1c) ≥6.5% (OR: 1.603; 95% CI: 1.143-2.249; P=0.006), postoperative fever of unknown origin [temperature (T) >38 â; OR: 2.494; 95% CI: 1.321-4.708; P=0.005], postoperative hypoalbuminemia (intravenous albumin administration for ≥2 days; OR: 14.125; 95% CI: 1.777-112.282; P=0.012). Conclusions: Multivariate analysis showed that history of secondary lung surgery, preoperative HbA1c ≥6.5%, postoperative fever of unknown origin (T >38 â), and postoperative hypoalbuminemia (<35 g/L and intravenous albumin administration ≥2 days) were the independent risk factors for empiric antibiotic escalation therapy after minimally invasive lung surgery. For preoperative risk factors, further cohort studies should be conducted to explore better intervention indicators or measures. For postoperative risk factors, perioperative dynamic monitoring of procalcitonin can guide the rational use of antibiotics, reduce the risk of drug resistance and hospitalization cost.
