Gas-phase preparation of silylacetylene (SiHCCH) through a counterintuitive ethynyl radical (CH) insertion.

Elementary reaction mechanisms constitute a fundamental infrastructure for chemical processes as a whole. However, while these mechanisms are well understood for second-period elements, involving those of the third period and beyond can introduce unorthodox reactivity. Combining crossed molecular beam experiments with electronic structure calculations and molecular dynamics simulations, we provide compelling evidence on an exotic insertion of an unsaturated sigma doublet radical into a silicon-hydrogen bond as observed in the barrierless gas-phase reaction of the D1-ethynyl radical (CD) with silane (SiH).

Heterocyclic phytometabolites formononetin and arbutin prevent oxidative and alkylation-induced mutagenicity.

Phenolic phytometabolites are promising bioactive compounds for management of genomic instability related diseases. Formononetin (FMN) and arbutin (ARB) are found in several plant sources. Our goal was to investigate the safety and efficacy of FMN and ARB using both standardized and alternative toxicogenetic methods.

Data-driven stabilization of NiPd nanoalloys: a study using density functional theory and data mining approaches.

Green hydrogen, generated through the electrolysis of water, is a viable alternative to fossil fuels, although its adoption is hindered by the high costs associated with the catalysts. Among a wide variety of potential materials, binary nickel-palladium (NiPd) systems have garnered significant attention, particularly at the nanoscale, for their efficacious roles in catalyzing hydrogen and oxygen evolution reactions. However, our atom-level understanding of the descriptors that drive their energetic stability at the nanoscale remains largely incomplete.

Anti-Sporothrix Activity of Novel Copper-Itraconazole Complexes.

A series of new metal complexes, [Cu(ITZ)Cl] ⋅ 5HO (1) [Cu(NO)(ITZ)] ⋅ 3HO ⋅ CHO (2) and [Cu(ITZ))(PPh)]NO ⋅ 5HO (3) were synthesized by a reaction of itraconazole (ITZ) with the respective copper salts under reflux. The metal complexes were characterized by elemental analyses, molar conductivity, H and C{H} nuclear magnetic resonance, UV-Vis, infrared and EPR spectroscopies. The antifungal activity of these metal complexes was evaluated against the main sporotrichosis agents: Sporothrix brasiliensis, Sporothrix schenkii, and Sporothrix globosa.

Correction: Quantum and semiclassical studies of nonadiabatic electronic transitions between N(S) and N(D) by collisions with N.

Correction for 'Quantum and semiclassical studies of nonadiabatic electronic transitions between N(S) and N(D) by collisions with N' by Dandan Lu , , 2023, , 15656-15665, https://doi.org/10.1039/D3CP01429K.

CD155/PVR determines acute myeloid leukemia targeting by Delta One T cells.

Relapsed or refractory acute myeloid leukemia (AML) remains a major therapeutic challenge. We have recently developed a Vδ1+ γδ T cell-based product for adoptive immunotherapy, named Delta One T (DOT) cells, and demonstrated their cytolytic capacity to eliminate AML cell lines and primary blasts in vitro and in vivo. However, the molecular mechanisms responsible for the broad DOT-cell recognition of AML cells remain poorly understood.

Computational screening of silver-based single-atom alloys catalysts for CO2 reduction.

Electrocatalytically reducing CO2 into value-added products is a challenging but promising process. Catalysts have been proposed to reduce the potential necessary for the reaction to occur, among which single-atom alloys (SAAs) are particularly promising. Here, we employ density functional theory calculations and the computational electrode model to predict whether silver-based SAAs have the potential to be effective electrocatalysts to convert CO2 into C1 products.

Theoretical study of the O(3P) + CN(X2Σ+) → CO(X1Σ+) + N(2D)/N(4S) reactions.

The barrierless exothermic reactions between atomic oxygen and the cyano radical, O(3P) + CN(X2Σ+) → CO(X1Σ+) + N(2D)/N(4S), play a significant role in combustion, astrochemistry, and hypersonic environments. In this work, their dynamics and kinetics are investigated using both wave packet (WP) and quasi-classical trajectory (QCT) methods on recently developed potential energy surfaces of the 12A', 12A,″ and 14A″ states. The product state distributions in the doublet pathway obtained with the WP method for a few partial waves show extensive internal excitation in the CO product.

Underlying mechanisms of gold nanoalloys stabilization.

Gold nanoclusters have attracted significant attention due to their unique physical-chemical properties, which can be tuned by alloying with elements such as Cu, Pd, Ag, and Pt to design materials for various applications. Although Au-nanoalloys have promising applications, our atomistic understanding of the descriptors that drive their stability is far from satisfactory. To address this problem, we considered 55-atom model nanoalloys that have been synthesized by experimental techniques.

High-accuracy DMBE potential energy surface for CNO(A''4) and the rate coefficients for the C + NO reaction in the A'2, A''2, and A''4 states.

An accurate potential energy surface (PES) for the lowest lying A''4 state of the CNO system is presented based on explicitly correlated multi-reference configuration interaction calculations with quadruple zeta basis set (MRCI-F12/cc-pVQZ-F12). The ab initio energies are fitted using the double many-body expansion method, thus incorporating long-range energy terms that can accurately describe the electrostatic and dispersion interactions with physically motivated decaying functions. Together with the previously fitted lowest A'2 and A''2 states using the same theoretical framework, this constitutes a new set of PESs that are suitable to predict rate coefficients for all atom-diatom reactions of the CNO system.

Anti- Activity, Mutagenicity, Hepatocytotoxicity and Nitroreductase Enzyme Evaluation of 3-Nitrotriazole, 2-Nitroimidazole and Triazole Derivatives.

Chagas disease (CD), which is caused by and was discovered more than 100 years ago, remains the leading cause of death from parasitic diseases in the Americas. As a curative treatment is only available for the acute phase of CD, the search for new therapeutic options is urgent. In this study, nitroazole and azole compounds were synthesized and underwent molecular modeling, anti- evaluations and nitroreductase enzymatic assays.

Quantum and semiclassical studies of nonadiabatic electronic transitions between N(S) and N(D) by collisions with N.

The dynamics and kinetics of spin-forbidden transitions between N(D) and N(S) collisions with N molecules are investigated using a quantum wave packet (WP) method and the semi-classical coherent switches with decay of mixing (CSDM) method. These electronic transition processes are competing with exchange reaction channels on both the doublet and quartet potential energy surfaces. The WP and CSDM quenching rate coefficients are found in reasonable agreement with each other, and both reproduce the previous theoretical results.

In silico and in vitro assessment of anti-Trypanosoma cruzi efficacy, genotoxicity and pharmacokinetics of pentasubstituted pyrrolic Atorvastatin-aminoquinoline hybrid compounds.

Atorvastatin (AVA) is a third-generation statin with several pleiotropic effects, considered the last synthetic pharmaceutical blockbuster. Recently, our group described the effects of AVA on DNA damage prevention and against Trypanosoma cruzi infection. In this study, our aim was to evaluate the efficacy, safety, and in silico pharmacokinetic profile of four hybrids of aminoquinolines with AVA 4a-d against T.

Study of the Counter Cation Effects on the Supramolecular Structure and Electronic Properties of a Dianionic Oxamate-Based {Ni} Helicate.

Herein, we describe the synthesis, crystal structure, and electronic properties of {[K(dmso)(HO)][Ni(Hmpba)]·dmso·2HO} () and [Ni(HO)][Ni(Hmpba)]·3CHOH·4HO () [dmso = dimethyl sulfoxide; CHOH = methanol; and Hmpba = 1,3-phenylenebis(oxamic acid)] bearing the [Ni(Hmpba)] helicate, hereafter referred to as {Ni}. SHAPE software calculations indicate that the coordination geometry of all the Ni atoms in 1 and 2 is a distorted octahedron (O) whereas the coordination environments for K1 and K2 atoms in 1 are Snub disphenoid J84 (D) and distorted octahedron (O), respectively. The {Ni} helicate in is connected by K counter cations yielding a 2D coordination network with topology.

The role of single-atom Rh-dopants in the adsorption properties of OH and CO on stepped Ag(211) surfaces.

Several chemical reactions with commercial and environmental importance can benefit from the development of more active or selective heterogeneous catalysts. Particularly, those catalyzed by metallic surfaces are usually impacted by the presence of defects such as kinks and dopants. Here, we employed density functional theory calculations within van der Waals correction to investigate the effects of single-atom Rh-dopants in the adsorption properties of OH and CO on stepped Ag(211) surfaces.

Formation of phosphorus monoxide through the [Formula: see text] reaction.

Phosphorus is a key and vital element for a diverse set of important biological molecules, being indispensable for life as we know. A deeper comprehension of its role in astrochemistry and atmospheric chemistry may aid in finding answers to how this element became available on Earth. The PO molecule is one of the main reservoirs of phosphorus in the interstellar medium (ISM), and a better understanding of the mechanisms and rate coefficients for its formation in the ISM is important for modelling its abundances.

Quasiclassical Trajectory Study of the Si + SH Reaction on an Accurate Double Many-Body Expansion Potential Energy Surface.

An accurate potential energy surface (PES) for the HSiS system based on MRCI+ calculations extrapolated to the complete basis set limit is presented. Modeled with the double many-body expansion (DMBE) method, the PES provides an accurate description of the long-range interactions, including electrostatic and dispersion terms decaying as , , , , that are predicted from dipole moments, quadrupole moments, and dipolar polarizabilities, which are also calculated at the MRCI+ level. The novel PES is then used in quasiclassical trajectory calculations to predict the rate coefficients of the Si + SH → SiS + H reaction, which has been shown to be a major source of the SiS in certain regions of the interstellar medium.

Gas-Phase Preparation of Silyl Cyanide (SiHCN) via a Radical Substitution Mechanism.

The silyl cyanide (SiHCN) molecule, the simplest representative of a fully saturated silacyanide, was prepared in the gas phase under single-collision conditions via a radical substitution mechanism. The chemical dynamics were direct and revealed a pronounced backward scattering as a consequence of a transition state with a pentacoordinated silicon atom and almost colinear geometry of the attacking cyano radical and leaving hydrogen. Compared to the isovalent cyano (CN)-methane (CH) system, the CN-SiH system dramatically reduces the energy of the transition state to silyl cyanide by nearly 100 kJ mol, which reveals a profound effect on the chemical bonding and reaction mechanism.

Stability of neutral molecular polynitrogens: energy content and decomposition mechanisms.

The potential application of all-nitrogen molecules as high energy density materials (HEDMs) has been attracting considerable scientific effort. If stable enough to be synthesized and stored, these systems may be used as a green source of energy. However, it is very difficult to obtain these structures under mild experimental conditions.

Evaluation of alternative RNA extraction methods for detection of SARS-CoV-2 in nasopharyngeal samples using the recommended CDC primer-probe set.

Background: The efficiency of isolation and purification of the viral genome is a critical step to the accuracy and reliability of RT-qPCR to detect SARS-CoV-2. However, COVID-19 testing laboratories were overwhelmed by a surge in diagnostic demand that affected supply chains especially in low and middle-income facilities.

Objectives: Thus, this study compares the performance of alternative methods to extraction and purification of viral RNA in samples of patients diagnosed with COVID-19.

A novel naphthoquinone derivative shows selective antifungal activity against Sporothrix yeasts and biofilms.

Sporotrichosis is a subcutaneous mycosis that affects humans and animals, with few therapeutic options available in the pharmaceutical market. We screened the in vitro antifungal activity of fourteen 1,4-naphthoquinones derivative compounds against Sporothrix brasiliensis and Sporothrix schenckii, the main etiological agents of sporotrichosis in Latin America. The most active compound was selected for further studies exploring its antibiofilm activity, effects on yeast morphophysiology, interaction with itraconazole, and selectivity to fungal cells.

Relationship between ventricular repolarization parameters and the inducibility of ventricular arrhythmias during electrophysiological study in patients with coronary artery disease.

Objective: Risk stratification of sudden cardiac death in patients with coronary artery disease is of great importance. We evaluated the association between ventricular repolarization and induction of malignant ventricular arrhythmias on electrophysiological study of patients with coronary artery disease.

Methods And Results: A total of 177 patients (65±10.