Development and validation of a model to determine the risk of esophageal strictures after endoscopic submucosal dissection for esophageal neoplasms.

BACKGROUND: Currently, endoscopic submucosal dissection (ESD) is widely used as therapeutic methods for superficial esophageal neoplasms (SENs). However, patients are likely to develop esophageal strictures after ESD. Our study aims to explore the possible risk factors for esophageal strictures after ESD and develop and validate a risk model for predicting the progression of postoperative esophageal strictures. METHODS: Clinical data of patients who underwent ESD in our hospital for suspected early esophageal squamous cell carcinoma were collected from January 2014 to March 2020. The possible risk factors for postoperative esophageal strictures were analyzed by univariate and multivariate logistic regression analysis. Eventually, a risk-scoring model was built, in which 70% of patients were used to develop the model and the remaining 30% were used for validation. RESULTS: A total of 553 patients who received ESD were involved, and the incidence of esophageal strictures after ESD was 16.6% (92/553). In our study, the operating time, circumferential range, lesion location, depth of infiltration, and R0 resection were independent risk factors for esophageal strictures after ESD. According to the risk of postoperative esophageal stenosis, a risk-scoring model for esophageal strictures prediction was developed. The risk score ranged from 0 to 11 points, and the risk scores were divided into low risk (0-3 points), intermediate risk (4-7 points), and high risk (8-11 points). The proportions of esophageal stenosis progression in the corresponding risk categories were 6.33%, 29.14%, and 100%. CONCLUSIONS: We developed a risk-scoring model based on factors including circumferential range, lesion location, depth of infiltration, and R0 resection. It stratified patients into low-, intermediate-, and high-risk groups for postoperative esophageal strictures development. This scoring model may have the potential to guide the management of patients after ESD in the future.

Direct Oxygen Transfer from H2 O to Cyclooctene over Electron-Rich RuO2 Nanocrystals for Epoxidation and Hydrogen Evolution.

Production of more than 20 million tons of epoxides per year from olefins suffers from low atom economy due to the use of oxidants and complex catalysts with unsatisfactory selectivity, leading to huge environmental and economic costs. We present a proof-of-concept application of electron-rich RuO2 nanocrystals to boost the highly selective epoxidation of cyclooctene via direct oxygen transfer from water as the sole oxygen source under mild conditions. The enhanced electron enrichment of RuO2 nanocrystals via the Schottky effect with nitrogen-doped carbons largely promotes the capture and activation of cyclooctene to give a high turnover frequency (260 h-1 ) of cyclooctene oxide, far surpassing the reported values (<20 h-1 ) of benchmarked catalysts at room temperature with oxidants. Our electron-rich RuO2 electrocatalysts enable efficient and durable hydrogen production (Faradaic efficiency >90 %) on the cathode without impacting on the selectivity to epoxide (>99 %) on the anode.

Boosting Mass Exchange between Pd/NC and MoC/NC Dual Junctions via Electron Exchange for Cascade CO2 Fixation.

Merging existing catalysts together as a cascade catalyst may achieve "one-pot" synthesis of complex but functional molecules by simplifying multistep reactions, which is the blueprint of sustainable chemistry with low pollutant emission and consumption of energy and materials only when the smooth mass exchange between different catalysts is ensured. Effective strategies to facilitate the mass exchange between different active centers, which may dominate the final activity of various cascade catalysts, have not been reached until now, even though charged interfaces due to work function driven electron exchange have been widely observed. Here, we successfully constructed mass (reactants and intermediates) exchange paths between Pd/N-doped carbon and MoC/N-doped carbon induced by interfacial electron exchange to trigger the mild and cascade methylation of amines using CO2 and H2. Theoretical and experimental results have demonstrated that the mass exchange between electron-rich MoC and electron-deficient Pd could prominently improve the production of N,N-dimethyl tertiary amine, which results in a remarkably high turnover frequency value under mild conditions, outperforming the state-of-the-art catalysts in the literature by a factor of 5.9.