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The recent terrorist attacks using Novichok agents and subsequent operations have necessitated an understanding of its physicochemical properties, such as vapor pressure and toxicity, as well as unascertained nerve agent structures. To prevent continued threats from new types of nerve agents, the organization for the prohibition of chemical weapons (OPCW) updated the chemical weapons convention (CWC) schedule 1 list. However, this information is vague and may encompass more than 10 000 possible chemical structures, which makes it almost impossible to synthesize and measure their properties and toxicity. To assist this effort, we successfully developed machine learning (ML) models to predict the vapor pressure to help with escape and removal operations. The model shows robust and high-accuracy performance with promising features for predicting vapor pressure when applied to Novichok materials and accurate predictions with reasonable errors. The ML classification model was successfully built for the swallow globally harmonized system class of organophosphorus compounds (OP) for toxicity predictions. The tuned ML model was used to predict the toxicity of Novichok agents, as described in the CWC list. Although its accuracy and linearity can be improved, this ML model is expected to be a firm basis for developing more accurate models for predicting the vapor pressure and toxicity of nerve agents in the future to help handle future terror attacks with unknown nerve agents.

A polymer/small-molecule binary-blend hole transport layer provided balanced charge transport and efficient recombination of electrons and holes in the perovskite layer, and an optimal device based on the blended HTL shows the highest EQE of 5.30%.

Semiconducting lead halide perovskite nanocrystals (PNCs) are regarded as promising candidates for next-generation optoelectronic devices due to their solution processability and outstanding optoelectronic properties. While the field of light-emitting diodes (LEDs) and photovoltaics (PVs), two prime examples of optoelectronic devices, has recently seen a multitude of efforts towards high-performance PNC-based devices, realizing both devices with high efficiencies and stabilities through a single PNC processing strategy has remained a challenge. Herein we demonstrate that diphenylproplyammonium (DPAI) surface ligands, found through a judicious ab initio based ligand search, provide a solution to this problem. Our universal PNC ink with DPAI ligands, prepared through a solution-phase ligand exchange process, simultaneously allows single-step processed LED and PV devices with peak electroluminescence external quantum efficiency of 17.00% and power conversion efficiency of 14.92% (stabilized output 14.00%), respectively. We reveal that a careful design of the aromatic rings such as in DPAI is the decisive factor in bestowing such high performances, ease of solution processing, and improved phase stability up to 120 days. Our work illustrates the power of ligand design in producing nanocrystal ink formulations for high-throughput production of optoelectronic devices; it also paves a path for "dual-mode" devices with both PV and LED functionalities. This article is protected by copyright. All rights reserved.

Complete surface passivation of colloidal quantum dots (CQDs) and their strong electronic coupling are key factors toward high-performance CQD-based photovoltaics (CQDPVs). Also, the CQD matrices must be protected from oxidative environments, such as ambient air and moisture, to guarantee air-stable operation of the CQDPVs. Herein, we devise a complementary and effective approach to reconstruct the oxidized CQD surface using guanidinium and pseudohalide. Unlike conventional halides, thiocyanate anions provide better surface passivation with effective replacement of surface oxygen species and additional filling of defective sites, whereas guanidinium cations promote the construction of epitaxial perovskite bridges within the CQD matrix and augment electronic coupling. Additionally, we replace a defective 1,2-ethanedithiol-treated CQD hole transport layer (HTL) with robust polymeric HTLs, based on a judicious consideration of the energy level alignment established at the CQD/HTL interface. These efforts collectively result in high-performance and stable CQDPVs with photocurrents over 30 mA cm

We report morphological control with phenyl-C60-butyric acid methyl ester (PCBM) molecular aggregation for perovskite–PCBM bulk heterostructure (Pe–PCBM BHS) solar cells. Solar cells prepared via the Pe–PCBM BHS method exhibited a higher power conversion efficiency (PCE) of 18% than 11% from a device with a conventional planar heterojunction structure. The Pe–PCBM BHS can enhance device efficiency by improving electron transfer, shortening the electron transport length required for collection, and reducing the charge transfer resistance at the interface between the perovskite and PCBM through an increase of the perovskite crystal size and construction of a vertical perovskite–PCBM intermixing zone. To the best of our knowledge, the high PCE achieved by our Pe–PCBM BHS is the highest value to be reported in an inverted perovskite solar cell without buffer layers, such as metal oxides or low work function metals.

Next-generation electroluminescent displays require efficient and stable red, green and blue light-emitting diodes (LEDs) with low cost, excellent color purity and flexibility, for which perovskite-based LEDs (PeLEDs) are a promising candidate. Among the three primary colors, the low efficiencies and poor stability of blue PeLEDs is the major hurdle to their commercialization. Here, we report an in situ surface engineering strategy incorporating a simple hot injection method with one pot synthesis for surface passivation of cadmium ions (Cd2+) into blue-emissive all-inorganic perovskite nanocrystals (PNCs). The optimized PNCs containing 0.2% Cd show improved photoluminescence quantum yield (PLQY; 66.8%) and ambient stability compared to the neat PNCs (25.5%) at an emission wavelength of 475 nm. PeLEDs with the PNCs show a luminance of 51 cd m−2 and EQE of 3.71%. Through a series of ab initio calculations and comprehensive XPS analysis, we show that Cd incorporation into systems with reduced dimensionality such as PNCs likely takes place via surface inclusion in the perovskite B-site, which effectively suppresses the formation of halide defects and yields enhanced device efficiencies.

Mutations introduced into S19, a recombinant staphylococcal enterotoxin B vaccine candidate, contribute to its reduced cytokine induction in vivo by removing hydrogen bonds and allowing interaction with the T-cell receptor beta chain and major histocompatibility complex class II., Four mutations (N23A, Y90A, R110A and F177A) were introduced into S19, a vaccine candidate for staphylococcal enterotoxin B (SEB), resulting in a lower binding affinity towards the T-cell receptor beta chain (TCB) and reducing its superantigen activity. The structure of S19 was solved and was superposed on the native or complex structure of SEB. In the superposition model, mutations that were introduced seemed to reduce the number of hydrogen bonds at the SEB–TCB interface. S19 also displayed an unexpected structural change around the flexible-loop region owing to the Y90A mutation. This local structural change provided evidence that the mutated form of S19 could have a lower affinity for major histocompatibility complex (MHC) class II than wild-type SEB.

Poly(3,4-ethylenedioxythiophene):poly-styrene sulfonate (PEDOT:PSS) is commonly used as a hole-transport material in optoelectronic devices such as organic and perovskite-based solar cells and light-emitting diodes. Moreover, PEDOT:PSS is suitable for fabricating flexible and roll-to-roll devices by solution processing. However, PEDOT:PSS has hygroscopic properties, and the water molecules it attracts can damage the active layer of devices, leading to reduced device stability. In this study, we develop a water-stable hole transport layer (HTL) in perovskite light-emitting diodes (PeLEDs) and organic light-emitting diodes (OLEDs) via a simple and effective method, which involves the modification of PEDOT:PSS with 2-pentacosa-10,12-diynamidoethylsulfate as a photo-crosslinking agent. Experimental results show that devices with the developed HTL show greater long-term stability than PeLEDs and OLEDs based on pristine PEDOT:PSS.