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Stenosis after esophageal endoscopic submucosal dissection (ESD) has a high incidence, and muscular injury is an important risk factor for esophageal stenosis. Hence, this study aimed to classify muscular injury degrees and investigate their association with postoperative stenosis. This retrospective study included 1033 patients with esophageal mucosal lesions treated with ESD between August 2015 and March 2021. Demographic and clinical parameters were analyzed, and stenosis risk factors were identified using multivariate logistic regression. A novel muscular injury classification system was proposed and used to investigate the association between different muscular injury degrees and postoperative stenosis. Finally, a scoring system was established to predict muscular injury. Of 1033 patients, 118 (11.4%) had esophageal stenosis. The multivariate analysis demonstrated that the history of endoscopic esophageal treatment, circumferential range, and muscular injury were significant risk factors for esophageal stenosis. Patients with type II muscular injuries tended to develop complex stenosis (n = 13 [36.1%], P <.05), and type II muscular injuries were more likely to predispose patients to severe stenosis than type I (73.3% and 92.3%, respectively). The scoring system showed that patients with high scores (3-6) were more likely to have muscular injury. The score model presented good discriminatory power in the internal validation (area under the receiver-operating characteristic curve,.706; 95% confidence interval,.645-.767) and goodness-of-fit in the Hosmer-Lemeshow test (P =.865). Muscular injury was an independent risk factor for esophageal stenosis. The scoring system demonstrated good performance in predicting muscular injury during ESD. [Display omitted] [ABSTRACT FROM AUTHOR]

Accurately simulating the aerodynamic characteristics is important to the safety and stability of high-speed train, especially when it operates under strong crosswinds. In recent, long span highway-railway bridge has been developed rapidly to enable the high-speed rail to cross wide rivers and valleys, where the truss bridges are usually served as the main girder type. This study aims to investigate the unique interference effects on the aerodynamic characteristics of the high-speed train caused by the truss bridge, i.e., the so-called shielding effect and internode effect. The shielding effect of the truss bridge on the mean aerodynamic coefficients is firstly quantified based on a moving train model test in wind tunnel. Combined with a 3-D computational fluid dynamic (CFD) model validated by the wind tunnel test, a series of numerical simulations are conducted to study the mechanism of internode effect, where the airflow field and pressure distributions around the train body and on the bridge surface are interpreted. The results reveal that the truss bridge has an obvious whole and local shielding effects, with the first effect introducing a remarkable decrease on the aerodynamic forces of trains at the entrance and the second effect leading to an intermittent excitation. • The particular shielding and internode effects of truss bridge on train's aerodynamic characteristics are analyzed. • The shielding effect is quantified based on a moving train model test in wind tunnel. • The intermittent excitation caused by internode effect is affected by the wind velocity and train speed. • The airflow field and pressure distributions around the train body and on the bridge surface are interpreted. [ABSTRACT FROM AUTHOR]

The gut microbiota plays a critical role in the appropriate development and maintenance of the enteric nervous system (ENS). Esophageal achalasia (EA) is a rare motility disorder characterized by the selective degeneration of inhibitory neurons in the esophageal myenteric plexus. This study aimed to evaluate the composition of the esophageal microbiota in achalasia and explore the potential microbial mechanisms involved in its pathogenesis. The lower esophageal mucosal microbiota was analyzed in patients with achalasia and control participants using 16 S rRNA sequencing. The association between the esophageal microbiota and achalasia was validated by inducing esophageal dysbiosis in C57BL/10 J and C57BL/10ScNJ (TLR4KO) mice via chronic exposure to ampicillin sodium in their drinking water. The esophageal microbiota in EA patients had lower diversity and a predominance of Gram-negative bacteria (Type II microbiota) compared to that in the healthy controls. Additionally, the relative abundance of Rhodobacter decreased significantly in patients with achalasia, which correlated with an enrichment of lipopolysaccharide (LPS) biosynthesis based on the COG database. Antibiotic-treated mice showed an esophageal microbiota characterized by increased abundance of Gram-negative bacteria (Type II microbiome), decreased abundance of Rhodobacter, and enriched LPS biosynthesis. Compared to the control and TLR4KO mice, the antibiotic-treated wild-type mice had higher LES resting pressure, increased LES contraction rate after carbachol stimulation, and decreased relaxation response to L -arginine. Moreover, the number of myenteric neurons decreased, while the number of lamina propria macrophages (LpMs) increased after antibiotic exposure. Furthermore, the TLR4-MYD88-NF-κB pathway was up-regulated, and the production of TNF-α, IL-1β, and IL-6 increased in the antibiotic-treated mice. Patients with achalasia exhibit esophageal dysbiosis, which may induce aberrant esophageal motility. [ABSTRACT FROM AUTHOR]