The Supplementary material contains additional theory (derivation of CP-SCF equations, additional contributions which arise from ECPs and point charges), figures and tables supporting conclusions drawn in the main text.
Accurate interaction energies can be obtained using high-level quantum chemical methods such as DLPNO-CCSD(T) and its HFLD variant in ORCA. The local energy decomposition (LED) scheme helps interpret these energies by breaking them down into chemically meaningful components. However, preparing LED inputs and analyzing results is often complex and error-prone. To streamline this process, we developed LEDAW (local energy decomposition analysis wizard), a Python-based tool that automates LED workflows. It supports standard and fragment-pairwise (fp)-LED, complete basis set (CBS) and Complete PNO Space (CPS) extrapolations, and analysis of N-body and cooperativity effects. With both a GUI and script-based workflow, LEDAW reduces analysis time from hours or days to just minutes, improving usability and reproducibility. It accelerates the generation of interaction energy matrices and heat maps, making advanced analysis of protein-ligand complexes, DNA assemblies, solute-solvent interactions, and molecular crystals more accessible.
Carboxylate-bridged Mn(II)–Ca(II) complexes are potentially relevant for mimicking the first stages of the Oxygen-Evolving Complex (OEC) assembly process. Here, we report on new homonuclear Ca(II) and heteronuclear Mn(II)–Ca(II) complexes with carboxylate-functionalized tripodal tris(2-pyridylmethyl)amine ligands, the heptadentate H<sub>3</sub>tpaa, previously reported, and the new hexadentate H<sub>2</sub>tpada, containing respectively three and two carboxylate units. The mononuclear [Ca(Htpaa)(OH<sub>2</sub>)] (Ca<sub>1</sub>) and dinuclear [Ca(tpada)(OH<sub>2</sub>)<sub>2</sub>]<sub>2</sub> (Ca<sub>2</sub>) calcium complexes, as well as the tetranuclear [{Mn(tpaa)}<sub>2</sub>{Ca(OH<sub>2</sub>)<sub>5</sub>(μ-OH<sub>2</sub>)}<sub>2</sub>][Mn(tpaa)]<sub>2</sub> (Mn<sub>2</sub>Ca<sub>2</sub>·2Mn) and dinuclear [Mn(tpada)ClCa(OH<sub>2</sub>)<sub>2.67</sub>(MeOH)<sub>2.33</sub>]Cl (MnCa) heterometallic species have been structurally characterized; the syntheses of Ca<sub>1</sub> and Mn<sub>2</sub>Ca<sub>2</sub>·2Mn being previously reported by us (Inorg. Chem., 2015, 54, 1283). The Mn(II) and Ca(II) are linked by two μ<sub>1,1</sub>-bridging carboxylates in MnCa, while only one μ<sub>1,3</sub>-carboxylate bridge connects each Ca<sup>2+</sup> ion to each Mn(II) in Mn<sub>2</sub>Ca<sub>2</sub>. A variable number of water molecules (n = 1 to 7) are coordinated to Ca in all complexes, most of them being involved in hydrogen-bond networks, in analogy to what occurs in the photosystem II. All donor atoms of the tpaa<sup>3−</sup> and tpada<sup>2−</sup> ligands are coordinated to the Mn<sup>2+</sup> ions, despite the unusually long distance between the Mn<sup>2+</sup> ion and the tertiary amine imposed by the constraining nature of the ligands, as supported by theoretical calculations. Solid state EPR spectroscopy, in combination with DFT calculations, has also shown that the Ca<sup>2+</sup> ion has an effect on the electronic parameters (zero field splitting) of the linked Mn(II) in the case of MnCa (μ<sub>1,1</sub>-carboxylate bridges). In Mn<sub>2</sub>Ca<sub>2</sub> (μ<sub>1,3</sub>-carboxylate bridge) the Ca<sup>2+</sup> ion induces only slight structural changes in the Mn coordination sphere.
Herein, we report a straightforward methodology for direct deaminative cyanation of anilines via aryl diazonium salts as fleeting intermediates. The approach leverages the kinetic stability of nitrate and copper cyanide, iron's ability to facilitate nitrate reduction, and appropriate relative rates to ensure the product-forming kinetic reaction pathway despite several thermodynamically favored, undesired reactions. We present insight into the previously unappreciated nitrate reduction mechanism by simple sulfur-based reductants, such as SO<sub>2</sub>. The oxylanion radical transfer mechanism is rarely encountered in synthetic chemistry but has ample precedent in biology and could provide a general, useful strategy for chemical nitrate reduction.
ABSTRACT Real‐time monitoring of microscopic chemical reactions offers valuable insight into reaction mechanisms, intermediate species, and the reaction kinetics involved. Mainstream electrochemical and chromatographic techniques are often complex, low‐sensitivity, failing to capture transient phenomena or distinguish similar chemical species within the reaction, limiting their accessibility for real‐time and continuing monitoring. Here, high‐resolution interface charge transfer mapping (ICTM) generated by liquid–solid contact electrification is used in situ for continuously monitoring potential chemical changes in the reactions. As liquid reactants slide dropwise over time along an insulating reclined plane, the ICTMs along the sample trajectory over time are recorded and is used to analysis chemical changes within the reactions. By means of time‐resolved ICTM measurements at statically charged dielectric surface, we have probed the dynamic evolution of redox reactions, tracked the organocatalytic reactions, and evaluated the agglomeration state of metal catalysts with a time resolution on the scale of seconds.
The advent of van der Waals (vdW) heterostructures has enabled formation of bespoke materials with atomic precision, where numerous quantum and topological phenomena have already been discovered. This atomic-layer tunability, however, comes at a cost: individual 2D layers must be picked up, moved, and placed in a deterministic manner while keeping their interfaces atomically clean. Recent advances in machine learning and robotics place even stronger emphasis on the deterministic aspect of vdW assembly. Current polymer-based transfer methods satisfy neither the determinism nor cleanliness requirements. To this end, solutions are needed where adhesion can be dynamically and deterministically controlled without leaving organic contamination. Here, we present a polymer-free transfer technique employing thin muscovite (mica) crystals. Temperature control over mica adhesion enables deterministic pick-up, stacking, and release of 2D materials, while their crystalline, inorganic nature ensures pristine interfaces and suppresses strain. Fully compatible with existing fabrication workflows, this approach enables the assembly of demanding vdW heterostructures, including those with exposed conductive layers, moiré superlattices and suspended membranes. Our method represents a promising strategy for vdW heterostructure fabrication toward its automatisation.
Objetivo: Determinar la tasa de recurrencia regional en pacientes diagnosticados con melanoma maligno cutáneo localizado en tronco y extre-midades, con una biopsia de ganglio centinela negativa. Métodos: Serie de casos. Se revisaron los registros de pacientes estadio clínico IB, IIA, IIB, IIIC tratados con biopsia de ganglio centinela entre enero de 2000 y diciembre de 2007. Se realizaron análisis descriptivos y se analizó la super-vivencia mediante el método de Kaplan-Meier. Resultados: Se incluyó a 170 pacientes. La mediana de seguimiento fue de 21,5 meses, con una tasa de recurrencia regional del 11,76%. La supervivencia global a 24 meses en ganglio centinela negativo fue del 100%. Conclusiones: La tasa de recurrencia regional en la serie analizada de pacientes con melanoma y ganglio linfático centinela negativo se halla dentro de lo reportado en la literatura, aunque el tiempo de seguimiento es relativamente corto.
Here, we report a one‐spot, temperature‐controlled AC electropolymerization strategy for converting graphene oxide and aniline into a crystalline, processable reduced graphene oxide (rGO)/polyaniline (PANI) composite for wearable ionic transistor textiles. By tuning the electropolymerization temperature from 4°C to 55°C under a low‐frequency triangular AC waveform, followed by mild postreduction, conformal polycrystalline PANI nanodomains are grown directly on rGO sheets. Low‐temperature synthesis yields the highest structural ordering and the lowest fraction of protonated imine species, directly linking growth conditions to mixed ionic–electronic transport behavior. The resulting rGO/PANI composite functions as an electrolyte‐gated transistor with stable operation and amplified gate response. Furthermore, the composite can be stencil printed onto cotton textiles to realize ratiometric Na + /K + sensing at constant ionic strength, highlighting its potential for scalable, wearable ion‐sensing architectures.
Emerging evidence suggests that alterations in immunometabolism contribute to pathogenesis of inflammatory diseases, providing potential therapeutic targets. Anti-inflammatory drugs such as glucocorticoids, metformin, and dimethyl fumarate (DMF) modulate key immunometabolic pathways. Glucocorticoids boost itaconate production, which exerts anti-inflammatory effects via multiple targets, including by modification of cysteines on inflammatory proteins. Metformin, known for inhibiting gluconeogenesis in type 2 diabetes, also blocks mitochondrial Complex I and increases GDF-15, a regulator of food intake with anti-inflammatory properties, which may explain effects of metformin on inflammation. DMF, like itaconate, modifies cysteines on target proteins, notably KEAP1, leading to Nrf2 activation, which induces antioxidant enzymes and suppresses inflammatory gene expression. These immunometabolic actions suggest that targeting immune cell metabolism could provide new strategies for treating autoimmune diseases. This review explores recent advances in itaconate, GDF-15, and Nrf2 signaling and how harnessing these pathways may lead to novel anti-inflammatory therapies for patients with inflammatory diseases.
Off-line analysis software in engineering safety assessment system has been developed in the rapid development of domestic dam safety automatic monitoring technique.The function and composition of the software have been introduced.The software has already been applied to an actual project and the result shows that it can make safety monitoring information function timely and effectively to provide reference and decision support for the project operation safety.
Read moreOne remarkable feature of catalysis in chemical synthesis is its capacity to override substrate-imposed reactivity and selectivity. The inversion of normal reaction patterns, commonly known as Umpolung, can be divided into (1) functional group Umpolung, where electrophilic groups are rendered nucleophilic (or vice versa), and (2) pericyclic Umpolung, in which the regioselectivity of pericyclic reactions is reversed relative to the predictions of frontier molecular orbital (FMO) theory. Although catalytic functional group Umpolung has been extensively investigated, the highly organized, concerted nature of pericyclic reactions makes inverting their conventional regioselectivity particularly challenging. To date, such inversion has been achieved only using engineered substrates or near-stoichiometric amounts of molecular cages. Here, we report an example of a chiral confined acid-catalyzed, asymmetric Umpolung of the Diels-Alder reaction. In our system, tropone reacts with enol ethers to deliver "contra-FMO" products with high yield, stereoselectivity, and regioselectivity. Mechanistic and computational studies indicate that a network of attractive noncovalent interactions, including π-π-interactions, nonclassical hydrogen bonding, and dispersion, governs the inverted regioselectivity. We anticipate that confined acid catalysis will open new avenues for addressing challenges in pericyclic Umpolung and regioselectivity control.
Read moreReal-time monitoring of microscopic chemical reactions offers valuable insight into reaction mechanisms, intermediate species, and the reaction kinetics involved. Mainstream electrochemical and chromatographic techniques are often complex, low-sensitivity, failing to capture transient phenomena or distinguish similar chemical species within the reaction, limiting their accessibility for real-time and continuing monitoring. Here, high-resolution interface charge transfer mapping (ICTM) generated by liquid-solid contact electrification is used in situ for continuously monitoring potential chemical changes in the reactions. As liquid reactants slide dropwise over time along an insulating reclined plane, the ICTMs along the sample trajectory over time are recorded and is used to analysis chemical changes within the reactions. By means of time-resolved ICTM measurements at statically charged dielectric surface, we have probed the dynamic evolution of redox reactions, tracked the organocatalytic reactions, and evaluated the agglomeration state of metal catalysts with a time resolution on the scale of seconds.
Read moreAbstract This perspective offers a personal reflection on the evolution, current status, and open challenges of quantum chemistry in the context of large molecular systems. Beginning with Dirac’s famous 1929 prophecy, I revisit the historical trajectory of our discipline, from the development of early conceptual models to the emergence of density functional theory and correlated wavefunction methods. While enormous progress has been made in algorithmic sophistication, enabling accurate calculations on systems with thousands of atoms, I argue that accurate energies alone do not solve the entirety of chemical problems. Real-world applications demand more than electronic structure: solvation, entropy, conformational complexity, and the sheer complexity of large molecules challenge our methods and our assumptions. Equally important are the conceptual and philosophical tensions that continue to shape the field, especially the difficult balance between prediction and understanding. I advocate for a more integrative approach that values models, insight, and falsifiability alongside numerical precision. Finally, I briefly consider the emerging role of machine learning and the implications of automation for the future of theory. This article is not a review but a dialogue – with the field, with its history, and with its practitioners.
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