A Comparative Study of Cationic Copper(I) Reagents Supported by Bipodal Tetramethylguanidinyl-Containing Ligands as Nitrene-Transfer Catalysts.

The bipodal compounds [(TMGbiphen)Cu-NCMe](PF) (R = Me, Ar (4-CFPh-)) and [(TMGbiphen)Cu-I] have been synthesized with ligands that feature a diarylmethyl- and triaryl-amine framework and superbasic tetramethylguanidinyl residues (TMG). The cationic Cu(I) sites mediate catalytic nitrene-transfer reactions between the imidoiodinane PhI = NTs (Ts = tosyl) and a panel of styrenes in MeCN, to afford aziridines, demonstrating comparable reactivity profiles. The copper reagents have been further explored to execute C-H amination reactions with a variety of aliphatic and aromatic hydrocarbons and two distinct nitrene sources PhI = NTs and PhI = NTces (Tces = 2,2,2-trichloroethylsulfamate) in benzene/HFIP (10:2 v/v).

Ionization Cross Sections of Hydrogen Molecule by Electron and Positron Impact.

We present ionization cross sections of hydrogen molecules by electron and positron impact for impact energies between 20 and 1000 eV. A three-body Classical Trajectory Monte Carlo approximation is applied to mimic the collision system. In this approach, the H molecule is modeled by a hydrogen-type atom with one active electron bound to a central core of effective charge with an effective binding energy.

Heat Treatments for Minimization of Residual Stresses and Maximization of Tensile Strengths of Scalmalloy Processed via Directed Energy Deposition.

Scalmalloy is an Al-Mg-Sc-Zr-based alloy specifically developed for additive manufacturing (AM). This alloy is designed for use with a direct aging treatment, as recommended by the manufacturer, rather than with a multistep treatment, as often seen in conventional manufacturing. Most work with Scalmalloy is conducted using powder bed rather than powder-fed processes.

Potential and perils: paths to protecting lunar sites of extraordinary scientific importance (SESIs) for astronomy before it is too late.

The Moon presents unique opportunities for high-impact astronomy that could enhance our understanding of our solar system, the possibility of life beyond Earth, and the evolution of the universe. A handful of locations on the lunar surface are 'sites of extraordinary scientific importance' (SESIs) for such studies, presenting opportunities for astronomical research unmatched anywhere else. For instance, the farside of the Moon, the most radio-quiet location in the inner solar system, could allow for the emplacement of telescopes to study the cosmic Dark Ages in ways that are impossible elsewhere.

Perfect Polar Alignment of Parallel Beloamphiphile Layers: Improved Structural Design Bias Realized in Ferroelectric Crystals of the Novel "Methoxyphenyl Series of Acetophenone Azines".

An improved design is described for ferroelectric crystals and implemented with the "methoxyphenyl series" of acetophenone azines, (MeO-Ph, Y)-azines with Y=F (1), Cl (2), Br (3), or I (4). The crystal structures of these azines exhibit polar stacking of parallel beloamphiphile monolayers (PBAMs). Azines 1, 3, and 4 form true racemates whereas chloroazine 2 crystallizes as a kryptoracemate.

3D-printed hydrogels dressings with bioactive borate glass for continuous hydration and treatment of second-degree burns.

Recent advances in additive manufacturing have led to the development of innovative solutions for tissue regeneration. Hydrogel materials have gained significant attention for burn wound treatment in clinical practice among various advanced dressings due to their soothing and moisturizing activity. However, prolonged healing, pain, and traumatic removal due to the lack of long-term wound hydration are some of the challenges in the treatment of second-degree burn wounds.

Chiral Recognition of Chiral (Hetero)Cyclic Derivatives Probed by Tetraaza Macrocyclic Chiral Solvating Agents via H NMR Spectroscopy.

In the field of chiral recognition, chiral cyclic organic compounds, especially heterocyclic organic compounds, have attracted little attention and have been rarely studied as chiral substrates by means of H NMR spectroscopy. In this paper, enantiomers of thiohydantoin derivatives, representing typical five-membered ,-heterocycles, have been synthesized and utilized for assignment of absolute configuration and analysis of enantiomeric excess. All enantiomers have been successfully differentiated with the assistance of novel tetraaza macrocyclic chiral solvating agents (TAMCSAs) by H NMR spectroscopy.

Second inflection point of supercooled water surface tension induced by hydrogen bonds: A molecular-dynamics study.

Surface tension of supercooled water is a fundamental property in various scientific processes. In this study, we perform molecular dynamics simulations with the TIP4P-2005 model to investigate the surface tension of supercooled water down to 220 K. Our results show a second inflection point (SIP) in the surface tension at temperature TSIP ≈ 267.

Using shock generator for the fuel mixing of the extruded single 4-lobe nozzle at supersonic combustion chamber.

The importance of the fuel injection configuration on the propulsion efficiency of high-speed vehicles is apparent. In this article, the use of an annular extruded 4-lobe nozzle for the injection of fuel jet in a supersonic combustor of a scramjet engine in the existence of a shock generator is examined. The main aim of this study is to obtain the efficient jet arrangement for efficient fuel mixing inside the engine of hypersonic vehicles.

Tailored (LaPrNdTbDy)CeO as a Highly Active and Stable Nanocatalyst for the Oxygen Evolution Reaction.

Designing highly active and robust catalysts for the oxygen evolution reaction is key to improving the overall efficiency of the water splitting reaction. It has been previously demonstrated that evaporation induced self-assembly (EISA) can be used to synthesize highly porous and high surface area cerate-based fluorite nanocatalysts, and that substitution of Ce with 50% rare earth (RE) cations significantly improves electrocatalyst activity. Herein, the defect structure of the best performing nanocatalyst in the series are further explored, NdCeO, with a combination of neutron diffraction and neutron pair distribution function analysis.

Antioxidant theranostic copolymer-mediated reduction in oxidative stress following traumatic brain injury improves outcome in a mouse model.

Following a traumatic brain injury (TBI), excess reactive oxygen species (ROS) and lipid peroxidation products (LPOx) are generated and lead to secondary injury beyond the primary insult. A major limitation of current treatments is poor target engagement, which has prevented success in clinical trials. Thus, nanoparticle-based treatments have received recent attention because of their ability to increase accumulation and retention in damaged brain.

Rare SNP in the gene interferes with RPA interaction and cellular function of HELB.

HELB is a human helicase involved in initiation of DNA replication, the replication stress response, and regulation of double-strand DNA break repair. rs75770066 is a rare SNP in the HELB gene that affects age at natural menopause. rs75770066 results in a D506G substitution in an acidic patch within the 1A domain of the helicase that is known to interact with RPA.

Designing explainable AI to improve human-AI team performance: A medical stakeholder-driven scoping review.

The rise of complex AI systems in healthcare and other sectors has led to a growing area of research called Explainable AI (XAI) designed to increase transparency. In this area, quantitative and qualitative studies focus on improving user trust and task performance by providing system- and prediction-level XAI features. We analyze stakeholder engagement events (interviews and workshops) on the use of AI for kidney transplantation.

Miniature Optical Fiber Fabry-Perot Interferometer Based on a Single-Crystal Metal-Organic Framework for the Detection and Quantification of Benzene and Ethanol at Low Concentrations in Nitrogen Gas.

This study reports for the first time, to the best of our knowledge, a real-time detection of ultralow-concentration chemical gases using fiber-optic technology, combining a miniaturized Fabry-Perot interferometer (FPI) with metal-organic frameworks (MOFs). The sensor consists of a short and thick-walled silica capillary segment spliced to a lead-in single-mode fiber (SMF), housing a tiny single crystal of HKUST-1 MOF, imparting chemoselectivity features. Ethanol and benzene gases were tested, resulting in a shift in the FPI interference signal.

Structure, dynamics, and redox reactivity of an all-purpose flavodoxin.

The flavodoxin of Rhodopseudomonas palustris CGA009 (Rp9Fld) supplies highly reducing equivalents to crucial enzymes such as hydrogenase, especially when the organism is iron-restricted. By acquiring those electrons from photodriven electron flow via the bifurcating electron transfer flavoprotein, Rp9Fld provides solar power to vital metabolic processes. To understand Rp9Fld's ability to work with diverse partners, we solved its crystal structure.

Effects of Laser Defocusing on Bead Geometry in Coaxial Titanium Wire-Based Laser Metal Deposition.

Coaxial wire-based laser metal deposition is a versatile and efficient additive process that can achieve a high deposition rate in the manufacturing of complex structures. In this paper, a three-beam coaxial wire system is studied, with particular attention to the effects of deposition height and laser defocusing on the resulting bead geometry. As the deposition standoff distance changes, so does the workpiece illumination proportion, which describes the ratio of energy going directly into the feedstock wire and into the substrate.

Biaxial strain tuned upconversion photoluminescence of monolayer WS.

Monolayer tungsten disulfide (1L-WS) is a direct bandgap atomic-layered semiconductor material with strain tunable optical and optoelectronic properties among the monolayer transition metal dichalcogenides (1L-TMDs). Here, we demonstrate biaxial strain tuned upconversion photoluminescence (UPL) from exfoliated 1L-WS flakes transferred on a flexible polycarbonate cruciform substrate. When the biaxial strain applied to 1L-WS increases from 0 to 0.

Electrocatalytic Asymmetric Nozaki-Hiyama-Kishi Decarboxylative Coupling: Scope, Applications, and Mechanism.

The first general enantioselective alkyl-Nozaki-Hiyama-Kishi (NHK) coupling reactions are disclosed herein by employing a Cr-electrocatalytic decarboxylative approach. Using easily accessible aliphatic carboxylic acids (via redox-active esters) as alkyl nucleophile synthons, in combination with aldehydes and enabling additives, chiral secondary alcohols are produced in a good yield with high enantioselectivity under mild reductive electrolysis. This reaction, which cannot be mimicked using stoichiometric metal or organic reductants, tolerates a broad range of functional groups and is successfully applied to dramatically simplify the synthesis of multiple medicinally relevant structures and natural products.

Mesoporous RECeO Fluorite Electrocatalysts for the Oxygen Evolution Reaction.

Developing highly active and stable electrocatalysts for the oxygen evolution reaction (OER) is key to improving the efficiency and practical application of various sustainable energy technologies including water electrolysis, CO reduction, and metal air batteries. Here, we use evaporation-induced self-assembly (EISA) to synthesize highly porous fluorite nanocatalysts with a high surface area. In this study, we demonstrate that a 50% rare-earth cation substitution for Ce in the CeO fluorite lattice improves the OER activity and stability by introducing oxygen vacancies into the host lattice, which results in a decrease in the adsorption energy of the OH* intermediate in the OER.

Elucidating the significant roles of root exudates in organic pollutant biotransformation within the rhizosphere.

Biotransformation of organic pollutants is crucial for the dissipation of environmental pollutants. While the roles of microorganisms have been extensively studied, the significant contribution of various root exudates are still not very well understood. Through plant growth experiment, coupled with gas and liquid chromatography-mass spectrometry methods, this study examined the effect of the presence of M.

The ACE inhibitor captopril inhibits ACN-1 to control dauer formation and aging.

The renin-angiotensin-aldosterone system (RAAS) plays a well-characterized role regulating blood pressure in mammals. Pharmacological and genetic manipulation of the RAAS has been shown to extend lifespan in Caenorhabditis elegans, Drosophila and rodents, but its mechanism is not well defined. Here, we investigate the angiotensin-converting enzyme (ACE) inhibitor drug captopril, which extends lifespan in worms and mice.

Reactive Capture and Conversion of CO into Hydrogen over Bifunctional Structured CeCoNiO/Ca Perovskite-Type Oxide Monoliths.

Carbon capture, utilization, and storage (CCUS) technologies are pivotal for transitioning to a net-zero economy by 2050. In particular, conversion of captured CO to marketable chemicals and fuels appears to be a sustainable approach to not only curb greenhouse emissions but also transform wastes like CO into useful products through storage of renewable energy in chemical bonds. Bifunctional materials (BFMs) composed of adsorbents and catalysts have shown promise in reactive capture and conversion of CO at high temperatures.