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Catalytic Asymmetric Construction of Si‐Chiral Silabicyclo[3.3.1]Nonanes Using Functionalized Prochiral Silacyclohexanones
ABSTRACT The development of chiral three‐dimensional, sp 3 ‐rich architectures to facilitate the discovery of potent functional molecules is at the forefront of synthetic chemistry. However, facile synthesis of saturated and bridged Si‐chiral silacycles remains elusive due to a lack of pluripotent Si‐prochiral platforms capable of diversity‐oriented asymmetric synthesis. Herein, we report the invention of functionalized prochiral 4,4‐disubstituted silacyclohexanones (FPDSs) as platforms for the modular synthesis of multifunctional sp 3 ‐rich Si‐chiral sila‐bicyclo[3.3.1]nonanes. The FPDS platforms are readily accessible via a newly established tandem S N 2‑substitution/Krapcho‑decarboxylation sequence as a key step to silacyclohexanone core. The utility of FPDS is demonstrated in catalytic asymmetric synthesis of diverse Si‐chiral sila‐bicyclo[3.3.1]nonanes via desymmetric intramolecular aldol reaction, tandem imine formation/Mannich, or Wittig/Michael sequence by chiral enamine catalysis, as well as α‐arylation by cooperative chiral enamine/palladium catalysis. Notably, this represents the first stereoselective method to produce functionalized sp 3 ‐rich Si‐chiral bridged silacycles and the first asymmetric organo/metal cooperative catalysis for forging Si‐chirality.
Perfluorocarbon nanodroplets are cytocompatible with osteoblast-lineage cells and modulate in vitro osteoclastogenesis differentially in normoxia and hypoxia
Abstract Perfluorocarbon nanodroplets (PFC NDs) are submicrometre particles comprising a liquid perfluorocarbon core stabilised by a phospholipid shell, with emerging potential for therapeutic targeted gas delivery and drug delivery. While related PFC microbubbles have demonstrated promise in drug delivery applications, including bone repair, the biological effects and translational relevance of PFC nanodroplets in skeletal systems remain untested. This study investigated the effects of nanodroplets on bone cell viability in vitro and on osteoclastogenesis under normoxic and hypoxic conditions. Confocal microscopy and flow cytometry were used to assess nanodroplet association with skeletally-relevant MC3T3-E1 and Saos-2 osteoblastic cell lines, human bone-marrow-derived stromal cells, and peripheral blood mononuclear cell-derived osteoclasts. Cellular viability and differentiation were evaluated using Alamar Blue, TRAP, and DAPI staining. Long-term (12-day) nanodroplet exposure significantly reduced osteoclast number in both normoxia and hypoxia, whereas short-term exposure in hypoxia increased osteoclast formation. Importantly, nanodroplets did not adversely affect osteoblastic viability. In summary, these findings indicate that PFC nanodroplets are compatible with key skeletal cell populations and can modulate osteoclastogenesis in a context-dependent manner, supporting their potential as vehicles for bone-targeted gas or drug delivery.
Forcing the Side‐on π‐Coordination of a C≡C Triple Bond to Technetium Using the <i>As</i> , <i>CC</i> , <i>As</i> Alkyne Pincer Ligand 1,2‐Bis(2‐(diisopropylarsaneyl)‐4‐(trifluoromethyl)phenyl)Ethyne
ABSTRACT Alkyne complexes are known for transition metals across the d‐block with exception of the radioelement technetium despite considerable synthetic efforts. DFT calculations suggest that this is not inherent to the transition metal but a consequence of the overall ligand sphere. The arsenic‐based tolane ligand 1,2‐bis(2‐(diisopropylarsaneyl)‐4‐(trifluoromethyl)phenyl)ethyne (L i Pr ) forces a coordination of the central alkyne moiety onto the metal through ligand design. The stable, crystalline Tc(III) and Tc(V) alkyne complexes mer ‐[Tc III Cl 3 (κ 4 ‐ As , CC , As ‐L i Pr )], mer ‐[Tc V NX 2 (κ 4 ‐ As , CC , As ‐L i Pr )] (X = Cl, Br) and cis,trans , mer ‐[Tc V N(CN)Cl(κ 4 ‐ As , CC , As ‐L i Pr )] alongside their rhenium homologs mer ‐[Re V Cl 3 (κ 4 ‐ As , CC , As ‐L i Pr )] and mer ‐[Re V NCl 2 (κ 4 ‐ As , CC , As ‐L i Pr )] have been prepared and fully characterized. According to spectroscopic and DFT analyses, the technetium complexes represent robust, classical 2e − alkyne complexes, while a different situation was found for mer ‐[Re V Cl 3 (κ 4 ‐ As , CC , As ‐L i Pr )] with a formally oxidized metal ion and reduced 4e − donor ligand. This has general implications for π‐ligand coordination in group 7 and potentially for neighboring elements. Successful translation to the medicinally relevant nuclear isomer 99m Tc proves the viability of alkyne donors as building blocks for stable chelation of technetium at the tracer level.
Role of capping agent on structure, composition and optical properties of ZnO nano-thin films for antibacterial activities
A study on the generation of traditional patterns in the perspective of AIGC–ancient Egyptian patterns as an example
Anomeric‐Effect‐Guided Saturated Weakly Solvating Electrolytes for Ultrastable High‐Voltage Sodium Metal Batteries
ABSTRACT Sodium metal batteries are promising for next‐generation energy storage, leveraging low‐cost sodium and highly reversible sodium metal anodes enabled by ether‐based electrolytes. However, the low oxidative stability of ether solvents severely limits the energy density of sodium metal batteries. Current strategies are focused on strengthening solvent interactions to improve stability or film‐forming electrolyte additives. Here, we propose an approach of designing saturated weakly solvating electrolytes (SWSEs) based on non‑fluorinated ethers and reveal that the overall oxidative stability is commonly governed by the weak solvents and anions. The SWSE saturates at 1 M, far below the concentrations required in locally high‑concentration electrolytes. Moreover, we identify ether solvents exhibiting the anomeric effect possess the notably enhanced oxidative stability through systematic molecular screening. Consequently, the SWSE based on the weak solvent of 1,3‐dioxane enables 1000 stable cycles of the sodium metal cell with the high cutoff voltage of 4.5 V. A practical sodium metal pouch cell consisting of a Na 0.67 Ni 0.33 Mn 0.67 O 2 cathode with the mass loading of 13.4 mg cm −2 and a thin‐foil sodium metal anode achieves stable cycling at 4.3 V. This work introduces a new strategy for developing high‐voltage sodium metal batteries and is expected to inspire advances in other high‐voltage metal batteries.
How the sausage is made: Testing the effectiveness of an informative video in promoting sustainable food consumption
Ordered Ba <sub>2</sub> EuIrO <sub>6</sub> Double Perovskite With Active Ir─O <sub>bri</sub> ─Eu Unit for Enhanced Electrocatalytic Oxygen Evolution in PEMWE
ABSTRACT The design of a low‐Ir‐loading anode catalyst with high activity and stability is crucial for the proton exchange membrane water electrolysis (PEMWE), yet it remains a formidable challenge. Herein, an ordered Ba 2 EuIrO 6 double perovskite is demonstrated as a promising anode material for catalyzing oxygen evolution reaction (OER) in acid electrolyte. The Ba 2 EuIrO 6 achieves a low overpotential of 250 mV at 10 mA cm −2 and high mass activity with 1.39 A mg −1 toward OER, outperforming BaIrO 3 and commercial IrO 2 catalysts. It is discovered that the oxygen bridged Ir─O bri ─Eu unit in Ba 2 EuIrO 6 plays a critical role as the catalytically active center. In situ spectroscopic studies, isotope labeling measurements and theoretical calculations reveal that the Ir─O bri ─Eu units possess strong proton affinity for proton capture from OOH* and OH*, triggering the bridging oxygen‐mediated deprotonation mechanism to break traditional scaling relationships during the OER. Furthermore, the incorporation of Eu modulates the Ir d z2 orbital to increase the spin density of adsorbed oxygen, accelerating ─OH attack and reducing the energy barrier for OOH* formation. The Ba 2 EuIrO 6 ‐loading PEMWE delivers over 1.0 A cm −2 at only 1.67 V and operates stably for 350 h at 1.0 A cm −2 , demonstrating its good potential for practical applications.
Study on the factor reduction of rockburst risk in coal mines
Bimetallic Ni <sub>3</sub> Fe/Ni <sub>2</sub> Fe <sub>2</sub> N Catalyst With Optimized <i>d</i> ‐Band Center for High‐Efficiency Lithium–Sulfur Batteries
ABSTRACT Lithium–sulfur batteries (LSBs) face significant challenges for practical application, primarily due to the sluggish reaction kinetics and pronounced shuttle effect of lithium polysulfides (LiPSs). This study proposes a synergistic strategy involving doping engineering and controlled nitridation‐induced electronic state modulation to fabricate a Ni 3 Fe/Ni 2 Fe 2 N composite as an efficient sulfur host material. This rational design integrates the strong catalytic activity of the metal alloy (Ni 3 Fe) with the high electrical conductivity of the nitride (Ni 2 Fe 2 N), enabling effective anchoring and conversion of polysulfides. Density functional theory (DFT) calculations and analysis results of XAFS and XPS confirm that an upshifted d‐ band center and modulated electronic states significantly enhance reaction kinetics and catalytic activity. In situ Raman spectroscopy and DRT analysis directly demonstrate the exceptional capability of the material to suppress the polysulfide shuttle effect. The battery exhibits remarkable cycling stability, achieving 1000 cycles with an ultralow decay rate of 0.045% per cycle. The outstanding performance is retained even under conditions as harsh as a high sulfur loading (4.3 mg cm −2 ) and low temperature (−10°C). This work not only presents a high‐performance catalyst but also provides new insights into the design of LSB catalysts via electronic state modulation.
Leveraging rpoB amplicon signals from Xpert MTB/RIF ultra as a diagnostic opportunity for identifying Non-tuberculous mycobacteria in TB-negative specimens
Radical‐Based On‐Surface Transformation of Nonplanar Aromatics Into Nonbenzenoid Nanographenes
ABSTRACT On‐surface synthesis has emerged as a powerful tool for atomically precise C─C bond formation, enabling access to low‐dimensional carbon‐based materials, often unattainable by conventional solution‐based chemistry. This approach gave rise to a novel class of magnetic materials, namely open‐shell magnetic nanographenes, whose magnetism originates primarily from unpaired electrons. Despite this progress, a fundamental understanding of selectivity and specificity of surface‐confined radical chemistry remains limited. Here, we demonstrate that nonplanar hydrocarbons such as helicenes undergo highly selective intramolecular radical‐driven bond formation and reorganization on an Au(111) surface, yielding nonbenzenoid nanographenes incorporating 5‐, 6‐, and 7‐membered rings. The products are identified using time‐of‐flight secondary ion mass spectrometry, scanning tunneling microscopy, and non‐contact atomic force microscopy, which collectively support a radical‐mediated cyclization pathway. The mechanism is distinct from the Diels–Alder cycloaddition and cyclodehydrogenation reactions previously reported for helicenes on surfaces.
Timber harvesting intensity and use of decision-support tools among semi-professional private forest owners: a Norwegian case study
Abstract Non-industrial private forest owners are known to have multiple ownership values and objectives. Their management decisions have multiple impacts on the supply of ecosystem services from forests. Forest management plans, a main decision-support tool for many forest owners, tend to be timber-oriented, potentially leading to more harvesting and more frequent use among production-oriented owners. We investigated factors explaining harvest intensity, measured as the ratio of property-level actual harvest volumes to predicted harvest volumes and the use of forest management plans among 119 semi-professional, non-industrial, private forest owners in Norway. Harvest intensity decreased with forest area and with biodiversity and nextgeneration’s need as ownership objectives and increased with wood prices and owner engagement but was not impacted by short-term profit or use of forest management plans. Use of forest management plans increased with forest area, having received instructions, trust in the harvest predictions, and economic ownership objectives. By using property-level harvest prediction, we could compare harvest figures to the actual timber resource, formed by each property’s forest biophysical attributes. This approach may be a valuable step in developing models that provide enhanced understanding of how forest owner behavior is shaped by preferences and objectives.
Fluorinative Rearrangement of Vinyl Diazo Compounds Enabled by a New Reactivity Mode of Cyclopropanediazonium Ions
ABSTRACT Although selective transformations of aromatic and purely aliphatic diazonium ions are well‐established, the reactivity of the unique cyclopropanediazonium (CPD) ions remains largely unexplored owing to their intrinsic instability. Herein, we report a new reaction mode of CPD ions mediated by hypervalent iodine reagents. The reaction enables a fluorinative 1,2‐diazo function migration of vinyl diazo compounds to afford synthetically useful but previously unavailable β,β‐difluorinated diazoester products. This transformation exhibits high efficiency, broad substrate scope, facile scalability, and complete chemo‐ and regioselectivity, alongside versatile downstream applications. Both control experiments and detailed DFT calculations suggest the formation of a key CPD ion intermediate that undergoes an unprecedented ring‐opening rearrangement of such species to furnish the product. Despite the pronounced complexity of the reaction pathway, which requires precise selectivity control at nearly every step, comprehensive computational analysis of a range of possible transition states elucidates the unusual reactivity and underlying origin of the observed selectivity.
Association of parental death and separation with child mortality in India
Probability characteristics and extreme value analysis of fluctuating wind pressure on heliostat arrays
Decoding Carbon Dot Purity by Nuclear Magnetic Resonance
ABSTRACT Carbon dots (CDs) have attracted increasing attention in recent years and have been widely explored in many fields. However, several challenges still limit their further development, particularly the unclear atomic structure and fluorescent mechanisms. Addressing these issues requires a thorough purification of crude CD products followed by reliable purity assessment. In this work, we combine dialysis and NMR analysis to evaluate the effectiveness of purification and consequent purity of CDs. Two representative CDs, citric acid‐ethylenediamine‐derived CDs and citric acid‐ p ‐phenylenediamine‐derived CDs were synthesized via hydrothermal treatments. The crude products were first filtered and aliquoted for dialysis. Collected retentates were characterized by microscopy and spectroscopy techniques. With increasing dialysis time, the mass of retentates gradually decreased reaching a steady state. In the NMR spectra, sharps peaks gradually attenuated and eventually disappeared, indicating progressive removal of impurities. Meanwhile, the ratio of integrated broad peaks to sharp peaks increased and reached a plateau with prolonged dialysis. A linear correlation was observed between CD purity and the integrated peak ratios. This work establishes a standardized and (semi‐)quantitative NMR‐based methodology for CD purity assessment, enabling a systematic differentiation and relative quantification of CDs and coexisting small molecular species, thereby addressing a key limitation of previous analyzes.
A user-friendly online tool for paleocoordinate calculation and 3D visualization
About the Role of Interfacial Lattice Oxygen in Pd─Pt Alloy for C─C Cleavage in Ethanol Electrooxidation
ABSTRACT The electrocatalytic ethanol oxidation reaction is bottlenecked by inefficient C─C bond cleavage. This challenge is epitomized at metal‐oxide heterointerfaces, where the active site identity and cleavage mechanism remain obscured. Here, we decoded this by atomically programming model PdO─Pt 3 Pd heterointerfaces. Through 18 O isotopic labeling, we identify the interfacial lattice oxygen (O Int ) in Pd 2+ ─O Int ─Pd alloy motif as the direct oxygen donor for C─C cleavage. The interfacial built‐in electric field activates O Int as a nucleophilic scalpel by upshifting its p‐band center, resulting in an ultralow cleavage barrier of 0.47 eV. Beyond a single site, we demonstrate that the interface functions as a reaction‐network architect. It creates a dominant O Int ‐mediated “non‐CO” C1 pathway at the PdO─Pt 3 Pd heterointerface while re‐engineering the traditional “CO” pathway on the adjacent Pt 3 Pd domain via threefold optimization: minimizing *CO source, suppressing acetate formation and ensuring rapid *CO removal. This dual‐path integration yields breakthrough performance with a mass activity of 9.09 A mg metal −1 and a C1‐pathway Faradaic efficiency of 75.6%. This work reports a paradigm shift from a passive “scavenger” model to an active “initial‐attack and system‐orchestration” mechanism, redefining heterointerfaces as atomically programmable reaction‐network architects. This paradigm offers a blueprint for mastering complex reaction networks, extending the frontier of rational catalyst design.