Background & Aims-Gastroesophageal reflux causes inflammation, intestinal metaplasia and its downstream sequelum adenocarcinoma in the distal esophagus. The incidence of esophageal adenocarcinoma has increased approximately 6-fold in the U.S. since the 1970s, accompanied with a significant increase in prevalence of gastroesophageal reflux disease (GERD). Despite extensive epidemiological study, the cause for GERD and the unexpected increases remain unexplainable. Microbes are among the environmental factors that may contribute to the etiology of GERD but very little research has been done on the esophageal microbiome, particularly in its relation to GERD. This is the first reported correlation between a change in the esophageal microbiome and esophageal diseases.

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Comprehensive review of unique effects of water on ionic liquids and deep eutectic solvents observed in experimental and theoretical studies.

Biological protein channels have many remarkable properties such as gating, high permeability, and selectivity, which have motivated researchers to mimic their functions for practical applications. Herein, using molecular dynamics simulations, we design bioinspired nanopores in graphene sheets that can discriminate between Na(+) and K(+), two ions with very similar properties. The simulation results show that, under transmembrane voltage bias, a nanopore containing four carbonyl groups to mimic the selectivity filter of the KcsA K(+) channel preferentially conducts K(+) over Na(+). A nanopore functionalized by four negatively charged carboxylate groups to mimic the selectivity filter of the NavAb Na(+) channel selectively binds Na(+) but transports K(+) over Na(+). Surprisingly, the ion selectivity of the smaller diameter pore containing three carboxylate groups can be tuned by changing the magnitude of the applied voltage bias. Under lower voltage bias, it transports ions in a single-file manner and exhibits Na(+) selectivity, dictated by the knock-on ion conduction and selective blockage by Na(+). Under higher voltage bias, the nanopore is K(+)-selective, as the blockage by Na(+) is destabilized and the stronger affinity for carboxylate groups slows the passage of Na(+) compared with K(+). The computational design of biomimetic ion-selective nanopores helps to understand the mechanisms of selectivity in biological ion channels and may also lead to a wide range of potential applications such as sensitive ion sensors, nanofiltration membranes for Na(+)/K(+) separation, and voltage-tunable nanofluidic devices.

A bicrystalline titanium dioxide nanofiber with enhanced photocatalytic activity was synthesized from potassium titanate K 2 Ti 2 O 5 via ion exchange and calcination. The nanofiber has a core-shell crystalline structure with a thin TiO 2 (B) phase sheathing the anatase core, as characterized by X-ray diffraction, Raman spectroscopy, and high-resolution transmission microscopy (HRTEM). From HRTEM and local electron diffraction patterns, the two crystalline phases form a coherent interface with the 0.34-nm spacing between the (102) planes of TiO 2 (B) matching that between the anatase (101) lattice planes. The core-shell anatase/TiO 2 (B) nanofiber shows enhanced photocatalytic activity in iodine oxidation reaction with a 20-50% increase in extent of reaction compared to either single-crystal anatase or single-crystal TiO 2 (B) nanofibers. Anatase and TiO 2 (B) have the same band gap value of 3.2 eV, while theoretical calculations show the conduction band (CB) and valence band (VB) energies in anatase are both lower than the corresponding CB and VB energies in TiO 2 (B). The enhanced photocatalytic property may be due to enhanced and concerted charge mobility toward or away from the anatase/TiO 2 (B) interface. The special structure-property relationship can provide a new strategy to design and fabricate efficient photocatalytic and photovoltaic materials.