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Two-dimensional (2D) hybrid perovskite sandwiched between two long-chain organic layers is an emerging class of low-cost semiconductor materials with unique optical properties and improved moisture stability. Unlike conventional semiconductors, ion migration in perovskite is a unique phenomenon possibly responsible for long carrier lifetime, current–voltage hysteresis, and low-frequency giant dielectric response. While there are many studies of ion migration in bulk hybrid perovskite, not much is known for its 2D counterparts, especially for ion migration induced by light excitation. Here, we construct an exfoliated 2D perovskite/carbon nanotube (CNT) heterostructure field effect transistor (FET), not only to demonstrate its potential in photomemory applications, but also to study the light induced ion migration mechanisms. We show that the FET I–V characteristic curve can be regulated by light and shows two opposite trends under different CNT oxygen doping conditions. Our temperature-dependent study indicates that the change in the I–V curve is probably caused by ion redistribution in the 2D hybrid perovskite. The first principle calculation shows the reduction of the migration barrier of I vacancy under light excitation. The device simulation shows that the increase of 2D hybrid perovskite dielectric constant (enabled by the increased ion migration) can change the I–V curve in the trends observed experimentally. Finally, the so synthesized FET shows the multilevel photomemory function. Our work shows that not only we could understand the unique ion migration behavior in 2D hybrid perovskite, it might also be used for many future memory function related applications not realizable in traditional semiconductors., A two-dimensional perovskite/carbon nanotube heterostructure was constructed not only to study light induced ion migration mechanisms, but also to demonstrate its potential in photomemory applications.

Immunoglobulin A (IgA) can inhibit intracellular viral replication during its transport across the epithelial cells. We find a monoclonal IgA antibody 7F1-IgA against the N-terminal moiety of the phosphoprotein (PNT) of measles virus (MV), which inhibits the intracellular replication of MV in Caco-2 cells but not in interferon-deficient Vero-pIgR cells. Transcytosis of 7F1-IgA across the MV-infected Caco-2 cells enhances the production of interferon-β (IFN-β) and the expression of IFN-stimulated genes, rendering Caco-2 cells with higher antiviral immunity. 7F1-IgA specifically interacts with MV phosphoprotein inside the MV-infected Caco-2 cell and prevents MV phosphoprotein from inhibiting the phosphorylation of JAK1 and STAT1. The intraepithelial interaction between 7F1-IgA and the viral phosphoprotein results in an earlier and stronger phosphorylation of JAK1 and STAT1 and, consequently, a more efficient nuclear translocation of STAT1 for the activation of the type I interferon pathway. Thus, IgA against phosphoprotein prevents a virus from evading type I IFN signaling and confers host epithelial cells efficient innate antiviral immunity, which potentiates a new antiviral target and an antiviral strategy.

This paper presents a detailed study of the influence of yttrium (Y) concentration on thermally stimulated luminescence (TSL) of LYSO:Ce crystals and establishes the relationship between electron traps and scintillation properties. With the increase of Y concentration, the glow curve shifts toward higher temperatures and the trap depth increases gradually. Our results revealed two groups of electron traps with one shallow (Et ≈ 0.10-0.26 eV) and one deep (Et ≈ 1.00-1.21 eV). Our TSL results suggest that the amount of shallow traps varied with Y content has a positive correlation with energy resolution, while the amount of deep traps is inversely proportional to light output. In order to analyze the variation trend of trap depths and their mechanism in detail, we calculated the band gap with the PBE functional and VUV excitation spectra. The results show that the increase of band gap possibly leads to the increase of deep electron trap depth.

Medical cannabis has been legally available for patients in a number of countries. Licensed producers produce a variety of cannabis strains with different concentrations of phytocannabinoids. Phytocannabinoids in medical cannabis are decarboxylated when subjected to heating for consumption by the patients or when extracted for preparing cannabis derivative products. There is little understanding of the true chemical composition of cannabis extracts, changes occurring during heating of the extracts, and their relevance to pharmacological effects. We investigated the extract from a popular commercial strain of medical cannabis, prior to and after decarboxylation, to understand the chemical profiles. A total of up to 62 compounds could be identified simultaneously in the extract derived from commercial cannabis, including up to 23 phytocannabinoids. Upon heating, several chemical changes take place, including the loss of carboxylic group from the acidic phytocannabinoids. This investigation attempts to reveal the chemical complexity of commercial medical cannabis extracts and the differences in the chemical composition of the native extract and the one subjected to heat. Comprehensive chemical analyses of medical cannabis extracts are needed for standardization, consistency, and, more importantly, an informed employment of this substance for therapeutic purposes.