Mass Cytometry and Single‐Cell RNA‐seq Profiling of the Heterogeneity in Human Peripheral Blood Mononuclear Cells Interacting with Silver Nanoparticles

Understanding the interactions between nanoparticles (NPs) and human immune cells is necessary for justifying their utilization in consumer products and biomedical applications. However, conventional assays may be insufficient in describing the complexity and heterogeneity of cell–NP interactions. Herein, mass cytometry and single‐cell RNA‐sequencing (scRNA‐seq) are complementarily used to investigate the heterogeneous interactions between silver nanoparticles (AgNPs) and primary immune cells. Mass cytometry reveals the heterogeneous biodistribution of the positively charged polyethylenimine‐coated AgNPs in various cell types and finds that monocytes and B cells have higher association with the AgNPs than other populations. scRNA‐seq data of these two cell types demonstrate that each type has distinct responses to AgNP treatment: NRF2‐mediated oxidative stress is confined to B cells, whereas monocytes show Fcγ‐mediated phagocytosis. Besides the between‐population heterogeneity, analysis of single‐cell dose–response relationships further reveals within‐population diversity for the B cells and naïve CD4⁺ T cells. Distinct subsets having different levels of cellular responses with respect to their cellular AgNP doses are found. This study demonstrates that the complementary use of mass cytometry and scRNA‐seq is helpful for gaining in‐depth knowledge on the heterogeneous interactions between immune cells and NPs and can be incorporated into future toxicity assessments of nanomaterials.     

Oxidation of Pu(IV) to Pu(VI) with an XeO<Subscript>3</Subscript> + H<Subscript>2</Subscript>O<Subscript>2</Subscript> Mixture in a Perchloric Acid Solution

In a perchloric acid solution, XeO₃ does not oxidize Pu(IV), but the addition of H₂O₂ leads to the accumulation of Pu(VI). It is assumed that Pu(IV) forms a complex with XeO₃. The reaction of the complex with hydrogen peroxide generates OH radicals, which oxidize Pu(IV) to Pu(V). The latter disproportionates to Pu(IV) and Pu(VI).     

Use of fluorescence to probe the surface dynamics during disorder-to-order transition and cluster formation in dihalonaphthalene-water thin films on Al2O3(0001)

Amorphous dihalonaphthalenes that are prepared by vacuum deposition onto a cold Al₂O₃ surface form electronically excited dimers when optically pumped, and their emission is characteristically red-shifted, broad and featureless compared to the monomeric fluorescence. If the surface is heated, the adlayer undergoes a disorder-to-order transition at a temperature characteristic of the molecule. Since pure crystalline dihalonaphthalenes typically fluoresce and do not exhibit excimeric features, the transition was studied by taking advantage of the changes in the spectral characteristics of the adlayer. These included transmittance, and emission from fluorescence and excimer. The combination of these methods allowed a close look at the surface dynamics of molecules on the surface of Al₂O₃ as the adlayer was heated from the deposition temperature to desorption.If a bilayer is formed by depositing water onto the surface with the organic adlayer on top, water, with its lower desorption energy, can be made to percolate into the organic layer. The optical probes indicate that the water clearly associates with the organic molecules while the excess water desorbs. By varying the coverage of either the water or the dihalonaphthalene, the stoichiometric composition of the cluster can be determined and are reported here.     

Improvement in thermoelectric properties of an n-type bismuth telluride (Bi2Se0.3Te2.7) due to texture development and grain refinement during hot deformation

Hot deformation of an n-type bismuth telluride (nBT of composition Bi₂Se_0.3Te_2.7) results in a texture characteristic of the deformation mode. Extruded nBT has a fiber texture with ?112?0? directions aligned with the extrusion direction. Rolling of previously textured (extruded) and untextured (sintered powder compact) material results in a rolling texture with the basal plane parallel to the rolling plane, and the ?112?0? directions randomly oriented on the rolling plane. Results indicate an improvement in thermoelectric figure of merit at 300 K from 0.79 in the as-received extruded material to 0.93 in the rolled material.