dz2 Band Links Frontier Orbitals and Charge Carrier Dynamics of Single-Atom Cocatalyst-Aided Photocatalytic H2 Production.

The Cu single-atom catalyst (SAC) supported on TiO2 exhibits outstanding efficacy in photocatalytic hydrogen evolution. The precise operational mechanism remains a subject of ongoing debate. The focus resides with the interplay linking heightened catalytic activity, dynamic valence state alterations of Cu atoms, and their hybridization with H2O orbitals, manifested in catalyst color changes. Taking anatase TiO2 (101) as a prototypical surface, we perform ab initio quantum dynamics simulation to reveal that the high activity of the Cu-SAC is due to the quasi-planar coordination structure of the Cu atom after H2O adsorption, allowing it to trap photoexcited hot electrons and inject them into the hybridized orbital between Cu and H2O. The observed alterations in the valence state and the coloration can be attributed to the H atom released during H2O dissociation and adsorbed onto the lattice O atom neighboring the Cu-SAC. Notably, this adsorption of H atoms puts the Cu-SAC into an inert state, as opposed to an activating effect reported previously. Our work clarifies the relationship between the high photocatalytic activity and the local dynamic atomic coordination structure, providing atomistic insights into the structural changes occurring during photocatalytic reactions on SACs.

Photothermally driven decoupling of gas evolution at the solid-liquid interface for boosted photocatalytic hydrogen production.

The slow mass transfer, especially the gas evolution process at the solid-liquid interface in photocatalytic water splitting, restricts the overall efficiency of the hydrogen evolution reaction. Here, we report a novel gas-solid photocatalytic reaction system by decoupling hydrogen generation from a traditional solid-liquid interface. The success relies on annealing commercial melamine sponge (AMS) for effective photothermal conversion that leads to rapid water evaporation. The vapor flows towards the photocatalyst covering the surface of the AMS and is split by the catalyst therein. This liquid-gas/gas-solid coupling system avoids the formation of photocatalytic bubbles at the solid-liquid interface, leading to significantly improved mass transfer and conversion. Utilizing CdS nanorods anchored by highly dispersed nickel atoms/clusters as a model photocatalyst, the highest hydrogen evolution rate from water splitting reaches 686.39 µmol h-1, which is 5.31 times that of the traditional solid-liquid-gas triphase system. The solar-to-hydrogen (STH) efficiency can be up to 2.06%. This study provides a new idea for the design and construction of efficient practical photocatalytic systems.

Remimazolam versus propofol for deep sedation/anaesthesia in upper gastrointestinal endoscopy in elderly patients: A multicenter, randomized controlled trial.

BACKGROUND AND OBJECTIVE: Propofol is the most commonly used sedative in gastrointestinal endoscopic procedures, but is associated with cardiorespiratory suppression, particularly in elderly patients. Remimazolam is a new short-acting GABA(A) receptor agonist with minimal impact on cardiorespiratory suppression, and may be a viable alternative in elderly patients undergoing endoscopic procedures. METHODS: This multicenter, randomized controlled trial was conducted between September 2020 and September 2021. Elderly patients (65-85 years of age) scheduled to undergo upper gastrointestinal endoscopy were randomized in 1:1 ratio to receive remimazolam tosilate (300 mg/h) or propofol (3 g/h) in addition to 50-µg fentanyl, until the Modified Observer's Assessment of Alertness/Sedation Scale (MOAA/S) reached ≤1. MOAA/S was maintained at 0 or 1 throughout the procedure using 2.5 mg remimazolam or 0.5 mg/kg propofol boluses in the two groups, respectively. The primary outcome was the rate of hypotension (defined as systolic blood pressure at ≤90 mmHg or > 30% decline vs. the baseline). Bradycardia was defined as heart rate ≤50 per minute; respiratory depression was defined as respiratory rate <8 per minute and/or SpO2 < 90%. RESULTS: A total of 400 patients (161 men and 239 women; 70.4 ± 4.6 years of age) were enrolled (200 patients per group). Average body mass index was 22.2 ± 2.4 kg/m2 . The rate of hypotension was 36.5% in the remimazolam group and 69.6% in the propofol group (p < 0.001). The remimazolam group also had a lower rate of bradycardia (1.5% vs. 8.5%, p < 0.001), respiratory depression (4.5% vs. 10.0%, p < 0.05) and pain at the injection site (0% vs. 12.0%, p < 0.001). CONCLUSION: Remimazolam was associated with a lower rate of hypotension in elderly patients undergoing upper gastrointestinal endoscopy under deep sedation/anaesthesia than propofol.

A physiology-based trigger score to guide perioperative transfusion of allogeneic red blood cells: A multicentre randomised controlled trial.

BACKGROUND: Restrictive blood transfusion is recommended by major guidelines for perioperative management, but requires objective assessment at 7-10 g/dl haemoglobin (Hb). A scoring system that considers the physiological needs of the heart may simply the practice and reduce transfusion. METHODS: Patients (14-65 years of age) undergoing non-cardiac surgery were randomised at a 1:1 ratio to a control group versus a Perioperative Transfusion Trigger Score (POTTS) group. POTTS (maximum of 10) was calculated as 6 plus the following: adrenaline infusion rate (0 for no infusion, 1 for ≤0.05 µg·kg-1 ·min-1 , and 2 for higher rate), FiO2 to keep SpO2 at ≥95% (0 for ≤35%, 1 for 36%-50%, and 2 for higher), core temperature (0 for <38°C, 1 for 38-40°C, and 2 for higher), and angina history (0 for no, 1 for exertional, and 2 for resting). Transfusion is indicated when actual Hb is lower than the calculated POTTS in individual patients. Transfusion in the control group was based on the 2012 American Association for Blood Banks (AABB) guideline. The primary outcome was the proportion of the patients requiring transfusion of allogeneic red blood cells (RBCs) during the perioperative period (until discharge from hospital), as assessed in the intention-to-treat (ITT) population (all randomised subjects). RESULT: A total of 864 patients (mean age 44.4 years, 244 men and 620 women) were enrolled from December 2017 to January 2021 (433 in the control and 431 in the POTTS group). Baseline Hb was 9.2 ± 1.8 and 9.2 ± 1.7 g/dl in the control and POTTS groups, respectively. In the ITT analysis, the proportion of the patients receiving allogeneic RBCs was 43.9% (190/433) in the control group versus 36.9% (159/431) in the POTTS group (p = 0.036). Lower rate of allogeneic RBCs transfusion in the POTTS group was also evident in the per-protocol analysis (42.8% vs. 35.5%, p = 0.030). Transfusion volume was 4.0 (2.0, 6.0) and 3.5 (2.0, 5.5) units (200 ml/unit) in the control and POTTS groups, respectively (p = 0.25). The rate of severe postoperative complications (Clavien-Dindo grade IIIa and higher) was 3.9% in the control group versus 1.2% in the POTTS group (p = 0.010). CONCLUSION: Transfusion of allogeneic RBCs based on the POTTS was safe and reduced the transfusion requirement in patients undergoing non-cardiac surgery.

The Impact on 30-Day Mortality From a Brief Focused Ultrasound-Guided Management Protocol Immediately Before Emergency Noncardiac Surgery in Critically Ill Patients: A Multicenter Randomized Controlled Trial.

OBJECTIVE: To determine whether brief ultrasound-guided treatment of hemodynamic shock and respiratory failure immediately before emergency noncardiac surgery reduced 30-day mortality. DESIGN: Parallel, nonblinded, randomized trial with 1:1 allocation to control and intervention groups. SETTING: Twenty-eight major hospitals within China. PARTICIPANTS: Six-hundred sixty patients ≥14 years of age, scheduled for emergency noncardiac surgery with evidence of shock (heart rate >120 beat/min, systolic blood pressure< 90 mmHg or requiring inotrope infusion), or respiratory failure (Pulse Oxygen Saturation <92%, respiratory rate >20 beat/min, or requiring mechanical ventilation). INTERVENTIONS: A brief (<15 minutes) focused ultrasound of ventricular filling and function, lung, and peritoneal spaces, with predefined treatment recommendation based on the ultrasound was performed before surgery or standard care. MEASUREMENTS AND MAIN RESULTS: The primary outcome was 30-day mortality. Secondary outcomes included changes in medical or surgical diagnosis and management due to ultrasound, intensive care unit, and hospital stay and cost, and Short Form-8 quality-of-life scores. Although there were frequent changes in diagnosis (82%) and management (49%) after the ultrasound, mortality at 30 days was not different between groups (50 [15.7%] v 53 [16.3%]; odds ratio 1.05, 0.69-1.6, p = 0.826). There were no differences in the secondary outcomes of the days spent in the hospital (mean 13.8 days, 95% confidence interval [CI] 12.1-15.6 v 14.4 d, 11.8-17.1, p = 0.718) or intensive care unit (mean 9.3 days, 95% CI 7.7-11.0 v 8.7 d, 7.2-10.2, p = 0.562), hospital cost (USD$14.5K, 12.2-16.7 v 13.7, 11.5-15.9, p = 0.611) or Short Form-8 scores at one year (mean 80.9, 95% CI 78.4-83.3 v 79.7, 76.9-82.5, p = 0.54) between participants allocated to the ultrasound and control groups. CONCLUSIONS: In critically ill patients with hemodynamic shock or respiratory failure, a focused ultrasound-guided management did not reduce 30-day mortality but led to frequent changes in diagnosis and patient management.

Efficient solar photocatalytic hydrogen production using direct Z-scheme heterojunctions.

We report the preparation of a series of heterojunctions made of Ta3N5 and TiO2 nanoparticles that show good properties for photocatalytic hydrogen production. The composite photocatalyst with a light-response range up to 620 nm shows a hydrogen evolution rate of 250 µmol h-1. The apparent quantum efficiency at 330 nm can be as high as 46%. Particularly, normalized spectral studies indicate that the heterojunction is more active upon full-spectrum (without using optical filters) irradiation, and its activity is even superior  to the total activity exhibited upon UV-light irradiation (λ ≤ 420 nm) and visible-infrared light irradiation (λ ≥ 420 nm). Moreover, in situ photodeposition of platinum nanoparticles on the surface of the photocatalyst as well as the band alignment analysis demonstrate the Z-scheme mechanism associated with the photocatalytic process. Specifically, photogenerated electrons from TiO2 will rapidly combine with the photogenerated holes from Ta3N5 through interfacial charge transfer, leaving the more active electrons and holes in Ta3N5 and TiO2, respectively, to facilitate redox reactions. Basically, TiO2 is only UV-light active, while Ta3N5 can be activated under visible-light irradiation. In this case, a synergy effect, upon simultaneous UV-light excitation and visible-light excitation, can be achieved by full-spectrum irradiation, leading to a much higher photocatalytic activity. This work thus provides a favorable and upward direction for the establishment of heterojunctions for high-efficiency hydrogen production and solar energy applications.

Restrictive Transfusion Strategy Does Not Affect Clinical Prognosis in Patients with Ectopic Pregnancy.

To assess the effects of restrictive transfusion strategy on hemoglobin (Hb) levels and prognosis in patients with ectopic pregnancy and severe hemorrhage undergoing emergency surgery, patient data were collected from 2012 to 2016. Following transfusion guidelines, restrictive transfusion was performed; at Hb levels of 60-70 to 100 g/L, transfusion was continued or not based on disease status. The patients were divided into four groups: blood loss < 400 ml (N1), 400-799 ml (N2), 800-1199 ml (N3), and ≥1200 ml (N4). Several prognosis parameters were assessed. Group N4 was further divided based on blood loss amounts (1200-1999, 2000-2999, 3000-3999, and 4000-5000 ml) for subgroup analyses. Blood loss, hemoglobin levels at discharge, and American Society of Anesthesiologists (ASA) scores were not associated with patient prognostic parameters, including intensive care unit (ICU) occupancy, cure, and healing rates, and surgical complications and hospital stay. No statistically significant difference was obtained in hospital stay among N1, N2, and N3 groups. Compared with N1 patients, cases with blood loss ≥ 1200 ml had significantly longer hospital stay. Interestingly, hospital stay was correlated with surgical approach, location of pregnancy, and operation time. Restrictive transfusion strategy could be safely used for emergency surgery in ectopic pregnancy with acute blood loss.