An sTGC Prototype Readout System for ATLAS New-Small-Wheel Upgrade

This paper presents a readout system designed for testing the prototype of Small-Strip Thin Gap Chamber (sTGC), which is one of the main detector technologies used for ATLAS New-Small-Wheel Upgrade. This readout system aims at testing one full-size sTGC quadruplet with cosmic muon triggers

Defining the chromatin signature of inducible genes in T cells

BACKGROUND Specific chromatin characteristics, especially the modification status of the core histone proteins, are associated with active and inactive genes. There is growing evidence that genes that respond to environmental or developmental signals may possess distinct chromatin marks. Using a T cell model and both genome-wide and gene-focused approaches, we examined the chromatin characteristics of genes that respond to T cell activation. RESULTS To facilitate comparison of genes with similar basal expression levels, we used expression-profiling data to bin genes according to their basal expression levels. We found that inducible genes in the lower basal expression bins, especially rapidly induced primary response genes, were more likely than their non-responsive counterparts to display the histone modifications of active genes, have RNA polymerase II (Pol II) at their promoters and show evidence of ongoing basal elongation. There was little or no evidence for the presence of active chromatin marks in the absence of promoter Pol II on these inducible genes. In addition, we identified a subgroup of genes with active promoter chromatin marks and promoter Pol II but no evidence of elongation. Following T cell activation, we find little evidence for a major shift in the active chromatin signature around inducible gene promoters but many genes recruit more Pol II and show increased evidence of elongation. CONCLUSIONS These results suggest that the majority of inducible genes are primed for activation by having an active chromatin signature and promoter Pol II with or without ongoing elongation

Direct synthesis of benzylic amines by palladium-catalyzed carbonylative aminohomologation of aryl halides

Benzylic amines are valuable compounds with important applications in areas including pharmaceuticals and agrochemicals. The known procedures for their synthesis are limited by difficulties in functionalizing the parent aminomethyl groups. On the other hand, carbonylation reactions offer a potent method to introduce carbonyl groups and homologate carbon chains. However, carbonylative aminohomologation of aryl halides is challenging due to competing reactions and the need to balance multiple sequential steps. Here we report a palladium-catalyzed carbonylative aminohomologation reaction for the direct aminomethylation of aryl halides. The reaction proceeds via a tandem palladium-catalyzed formylation, followed by imine formation and formic acid-mediated reduction. Useful functional groups including chloride, bromide, ester, ketone, nitro, and cyano are compatible with this reaction. Both aryl iodides and bromides are suitable substrates and a wide range of synthetically useful amines are efficiently obtained in moderate to excellent yields

The hidden spin-momentum locking and topological defects in unpolarized light fields

Electromagnetic waves characterized by intensity, phase, and polarization degrees of freedom are widely applied in data storage, encryption, and communications. However, these properties can be substantially affected by phase disorders and disturbances, whereas high-dimensional degrees of freedom including momentum and angular momentum of electromagnetic waves can offer new insights into their features and phenomena, for example topological characteristics and structures that are robust to these disturbances. Here, we discover and demonstrate theoretically and experimentally spin-momentum locking and topological defects in unpolarized light. The coherent spin is locked to the kinetic momentum except for a small coupling spin term, due to the simultaneous presence of transverse magnetic and electric components in unpolarized light. To cancel the coupling term, we employ a metal film acting as a polarizer to form some skyrmion-like spin textures at the metal/air interface. Using an in-house scanning optical microscopic system to image the out-of-plane spin density of the focused unpolarized vortex light, we obtained experimental results that coincide well with our theoretical predictions. The theory and technique promote the applications of topological defects in optical data storage, encryption, and decryption, and communications.Comment: 9 pages, 3 figures, 47 reference