Water Adsorption Isotherm and Surface Conductivity of Boroaluminosilicate Glasses.

The surface resistivity of boroaluminosilicate display glasses, which may affect the downstream display panel manufacturing, varies with the relative humidity (RH) of the environment, but the origin of this RH dependence has not been well understood. We have measured the water adsorption behavior on Corning Eagle XG (Glass-E) and Lotus NXT (Glass-L) glass panels using Brewster angle transmission infrared spectroscopy. The IR spectra of adsorbed water were analyzed to obtain the effective thickness of adsorbed water, the distribution of hydrogen-bonding interactions among the adsorbed water molecules, and the isosteric heat of water adsorption.

Prediction of glassy silica etching with hydrogen fluoride gas by kinetic Monte Carlo simulations.

Understanding the surface properties of glass during the hydrogen fluoride (HF)-based vapor etching process is essential to optimize treatment processes in semiconductor and glass industries. In this work, we investigate an etching process of fused glassy silica by HF gas with kinetic Monte Carlo (KMC) simulations. Detailed pathways of surface reactions between gas molecules and the silica surface with activation energy sets are explicitly implemented in the KMC algorithm for both dry and humid conditions.

Passivation of Mid-Gap Electronic States at Calcium Aluminosilicate Glass Surfaces upon Water Exposure: An Study.

When a clean glass surface is exposed to humid air, a thin water layer forms on the hydrophilic surface. Using molecular dynamics, we simulate the changes in the electronic structure of a CaO-AlO-SiO glass model upon vacuum fracture and subsequent exposure to HO. When the glass is fractured, dangling bonds form, which lower the band gap of the surface by ∼1.

Evaluating learning curves and competence in colorectal EMR among advanced endoscopy fellows: a pilot multicenter prospective trial using cumulative sum analysis.

Background And Aims: Data on colorectal EMR (C-EMR) training are lacking. We aimed to evaluate C-EMR training among advanced endoscopy fellows (AEFs) by using a standardized assessment tool (STAT).

Methods: This multicenter prospective study used a STAT to grade AEF training in C-EMR during their 12-month fellowship.

Nanoscale Structure and Dynamics of Water on Pt and Cu Surfaces from MD Simulations.

The interaction of liquid water with Pt(111) is investigated with classical molecular dynamics (MD) simulations, where the forces are determined using the third-generation charge optimized many-body (COMB3) interatomic potential. In cases of sub-monolayer water coverage, the parameterized empirical potential predicts experimentally observed and energetically favorable √37 and √39 reconstructed water structures with "575757" di-interstitial defects. At both sub-monolayer and multilayer water coverages, the structure of the first wetting layer of liquid water on Pt(111) exhibits a characteristic distribution where the molecules form two distinct buckled layers as a result of the interplay between water-metal adsorption and water-water hydrogen bonds.

Adherence to quality indicators in endoscopic surveillance of Barrett's esophagus and correlation to dysplasia detection rates.

Background And Aims: The American Gastroenterological Association introduced quality guidelines for the endoscopic management of Barrett's esophagus (BE) in 2015. Our aim was to determine if these guidelines are being followed and to correlate adherence with outcomes in surveillance endoscopy.

Methods: This is a retrospective study from December 2015 to June 2017.

Applied Potentials in Variable-Charge Reactive Force Fields for Electrochemical Systems.

An atomic description of water dynamics and electrochemical properties at electrode-electrolyte interfaces is presented using molecular dynamics with the third generation of the charge-optimized many-body (COMB3) potential framework. Externally applied potentials in electrochemical applications were simulated by offsetting electronegativity on electrode atoms. This approach is incorporated into the variable charge scheme within COMB3 and is used to investigate electrochemical systems consisting of two Cu electrodes and a water electrolyte with varying concentrations of hydroxyls (OH) and protons (H).

Effect of Surface Chemistry on Water Interaction with Cu(111).

The interfacial dynamics of water in contact with bare, oxidized, and hydroxylated copper surfaces are examined using classical molecular dynamics (MD) simulations. A third-generation charge-optimized many-body (COMB3) potential is used in the MD simulations to investigate the adsorption of water molecules on Cu(111), and the results are compared to the findings of density functional theory (DFT) calculations. The adsorption energies and structures predicted by COMB3 are generally consistent with those determined with DFT.

Preoperative Endoscopy Prior to Bariatric Surgery: a Systematic Review and Meta-Analysis of the Literature.

Background: There is debate regarding preoperative endoscopy (EGD) in patients undergoing bariatric surgery. Some centers perform EGD routinely in all patients; others perform EGD selectively. The objective of this study was to perform a systematic review and meta-analysis of the existing literature to estimate how frequently preoperative EGD changes management.

Pneumobilia Resulting From Choledochoduodenal Fistula Secondary to Metastatic Colon Adenocarcinoma.

Pneumobilia, or air within the biliary tree, is a poor prognostic indicator in a patient without prior biliary sphincterotomy. Differential diagnosis includes infection with gas-forming organisms, choledochoenteric fistula in the setting of gallstones or penetrating ulcer disease, malignant invasion from a primary liver or biliary tract tumor, or metastatic disease. Treatment depends on etiology and patient factors, but often requires surgical intervention.

Mon2 is a negative regulator of the monomeric G protein, Arl1.

Using site-directed mutants of ARL1 predicted to alter nucleotide binding, we examined phenotypes associated with the loss of ARL1 , including effects on membrane traffic and K (+) homeostasis. The GTP-restricted allele, ARL[Q72L] , complemented the membrane traffic phenotype (CPY secretion), but not the K (+) homeostasis phenotypes (sensitivity to hygromycin B, steady-state levels of K (+) , and accumulation of (86) Rb (+) ), while the XTP-restricted mutant, ARL1[D130N] , complemented the ion phenotypes, but not the membrane traffic phenotype. A GDP-restricted allele, ARL1[T32N] , did not effectively complement either phenotype.