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Abstract Nickel-catalyzed C–H bond functionalization reactions provide an impressive alternative to those with noble metal catalysts due to their unique reactivity and low cost. However, the regioselective C(sp2)–H borylation reaction of arenes accomplished by nickel catalyst remains limited. We herein disclose a silyl-directed ortho C(sp2)–H borylation of substituted arenes with a Ni(cod)2/PMe3/KHMDS catalyst system. Using readily available starting materials, this protocol provides easy access to ortho-borylated benzylic hydrosilanes bearing flexible substitution patterns. These products can serve as versatile building blocks for the synthesis of sila or sila/borine heterocycles under mild conditions. Control experiments and DFT calculations suggest that a catalytic amount of base prompts the formation of Ni(II)-Bpin-ate complex, likely related to the C(sp2)–H bond activation. This borylation reaction might follow an unusual Ni(II)/Ni(IV) catalytic cycle.

Abstract Achieving large-scale electrochemical CO2 reduction to multicarbon products with high selectivity using membrane electrode assembly (MEA) electrolyzers in neutral electrolyte is promising for carbon neutrality. However, the unsatisfactory multicarbon products selectivity and unclear reaction mechanisms in an MEA have hindered its further development. Here, we report a strategy that manipulates the interfacial microenvironment of Cu nanoparticles in an MEA to suppress hydrogen evolution reaction and enhance C2H4 conversion. In situ multimodal characterizations consistently reveal well-stabilized Cuδ+-OH species as active sites during MEA testing. The OH radicals generated in situ from water create a locally oxidative microenvironment on the copper surface, stabilizing the Cuδ+ species and leading to an irreversible and asynchronous change in morphology and valence, yielding high-curvature nanowhiskers. Consequently, we deliver a selective C2H4 production with a Faradaic efficiency of 55.6% ± 2.8 at 316 mA cm−2 in neutral media.

Phase transformations are feasible approaches for tailoring microstructures to achieve desired mechanical properties. However, the direct link between phase transformations and mechanical properties remains poorly studied. Here, using the theory of generalized stability (GS), we theoretically and experimentally correlate the bainitic transformation with the mechanical property of bainitic streels from a thermo-kinetic perspective. We established a quantitative relationship between the thermodynamic driving force and the yield strength, and explored the underlying physical correlation between the GS and the ductility. It is demonstrated that the thermodynamics-kinetics trade-off in the bainitic transformation inherently leads to the mutually exclusive relation between the yield strength and the uniform elongation. Specifically, a higher driving force generally results in an increased yield strength, while a larger GS tends to yield improved uniform elongation. Our findings provide fundamental insights into the relationship between the thermo-kinetics of bainitic transformation and mechanical properties, offering potential guidance for designing bainitic transformations to directly achieve superior mechanical performances.

Objective Closed reduction of pelvic injuries is a prerequisite and critical step in minimally invasive treatment. Achieving non‐invasive closed reduction of pelvic injuries is a challenging clinical problem. This study demonstrated a non‐invasive traction technique for closed reduction called countertraction closed reduction technique (CCRT) and evaluated its effectiveness for type C pelvic ring injuries. Method The data of patients with unstable pelvic fractures treated with CCRT and minimally invasive fixation were retrospectively reviewed from January 2017 to February 2022. Sacroiliac screws were placed to fix the posterior pelvic ring, and internal or external fixation was used to fix the anterior pelvic ring. Operation time, intraoperative blood loss, duration of hospital stay, fracture union and postoperative complications were recorded. Fracture reduction quality was evaluated using the Matta scoring criteria. Functional recovery and general quality of life were evaluated using the Majeed functional scoring criteria. Results Thirteen patients (nine males and four females), with an average age of 49.6 years were treated with CCRT and followed up for a mean of 18.5 months. The average operation time was 137.2 minutes (range 92–195 minutes), the average intraoperative blood loss was 31.2 mL (range 10–120 mL) and the average duration of hospital stay was 14.3 days (range 4–32 days). All patients achieved bony union with an average union time of 11.9 weeks (range 10–16 weeks). According to the Matta radiographic criteria, the quality of fracture reduction was excellent in eight patients, good in four, and fair in one. The average Majeed functional score was 89.7 (range 78–100). The functional evaluation revealed that the outcomes were excellent in nine patients, and good in four patients. Complications included incision fat liquefaction in one patient, and heterotopic ossification in another patient. There were no surgical complications as a result of CCRT. Conclusion CCRT is a non‐invasive closed reduction method for minimally invasive fixation of fresh Tile C1 and C2 pelvic fractures. The advantages of CCRT combined with minimally invasive treatment include a small surgical incision, reduced intraoperative bleeding, satisfactory fracture reduction, bone healing and functional recovery.

Gaining insights into overarching trends in chemical reaction systems is crucial for refining reaction conditions and developing novel reactions. These knowledgements include preferences for certain reagents, solvents, and functional group tolerance rules. Traditionally, synthetic chemists have relied on extensive literature searching to acquire the knowledge, a process that is both time-consuming and laborious. To streamline this process, we construct a standardized dataset and knowledge graph on an emerging domain, transition-metal-free transformations with organoborons. The dataset, compiled from organic reaction literature, includes comprehensive details of reaction scopes and conditions. The subsequent construction of a knowledge graph offers a visual representation of the reactions and their interrelationships. Through knowledge graph-based hierarchical analysis and density functional theory (DFT) calculations, we revealed the currently most frequently used reactants, synthetic conditions, and functional group rules in this field. We anticipate this knowledge graph-based approach will accelerate the acquisition and transfer of chemical reaction knowledge, catalyzing the discovery of new reactions. This work provides an automatic and adaptive framework for extracting key insights from reaction datasets to inform the design of novel reactions.

Iris color is a prominent phenotypic feature of quail. To understand the mechanism of melanin deposition related to quail iris color, iris tissues were selected from Beijing white and Chinese yellow quail for transcriptome analysis. Differentially expressed genes (DEGs) associated with pigmentation were identified using RNA sequencing and validated by quantitative real-time polymerase chain reaction (RT-qPCR). The identified single nucleotide polymorphisms were studied using bioinformatics and iris color correlation analyses. A total of 485 DEGs were obtained, with 223 upregulated and 262 downregulated. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses were performed. Thirty-two genes were annotated using the GO database. Three important pigment synthesis pathways (Notch signaling, melanogenesis, and tyrosine metabolism) were identified in quail iris tissue (P < 0.05). The expression levels of solute carrier family 45 member 2 (SLC45A2), tyrosinase-related protein 1, vitamin D receptor, opsin 5, and docking protein 5 were significantly different between Beijing white and Chinese yellow quail, as verified by RT-qPCR. The c.1061C>T mutation in SLC45A2, which caused a single amino acid change at position 354 (threonine to methionine), was significantly associated with iris color in Beijing white and Chinese yellow quail, and might be the main reason for the different iris colors between these two quail species.

The permittivity of soil-rock composite media is crucial for interpreting data originating from geophysical surveys such as ground-penetrating radar (GPR) imaging. At present, relevant theoretical research on the correlation analysis between the electrical and physical parameters of soil-rock composite media has not yet resulted in a complete reference system. This makes it difficult to characterize soil-rock composite media using the electromagnetic characteristic parameters of rock and soil media. In this study, the indoor electromagnetic testing method was used to extract electrical parameters such as the relative permittivity of soil-rock composite, and the influence of water content, density, soil-rock ratio, and other factors on the electrical parameters of soil-rock composite medium was analyzed. Furthermore, an artificial neural network prediction model was established, and the accuracy of the model was evaluated. The results showed that the relative permittivity tends to decrease with an increase in saturation when the moisture content of the mixture is high. The rock has a lower permittivity value than the surrounding soil particles. When the rock content increases, the average permittivity and conductive permittivity of the composite medium decreases. The main factors affecting the electrical properties of soil-rock composite media (in order of their influence, from most to least) are water content, compaction degree, and soil-rock ratio. These results provide a reliable reference for field geophysical exploration.

The exploration of Microwave detection of the Shubnikov-de Haas (SdH) effect as a contact-free characterization technique for different types of two dimensional semiconductor structures in the low magnetic field region, enables the detection of the character and relevance of the single-particle relaxation time which are distinguished from the usual transport scattering time. Other contact-free techniques such as cyclotron resonance, optically detected cyclotron resonance, and magneto-photoluminescence are applied to the same samples. The utility of these contact free techniques are compared with the microwave detection of the SdH effect, and the latter seems to have a wider range of applicability.

In mountainous landscapes, the diverse geotechnical conditions amplify landslide susceptibility. Factors such as precipitation and seismic activity can trigger landslides, while inherent hazards such as voids, fissures, and compaction deficits jeopardize long-term slope stability. Detecting and forecasting these susceptibilities accurately is crucial. In this paper, the time-domain finite-difference approach and the gprMax software are used to conduct forward modeling of landslide susceptibility. An electrical model of subsurface aqueous structures is created, including water-filled and air-filled cavities, fracture zones, and fault lines. The distinctive radar signal responses within these environments are examined, and a dataset of B-scan images associated with their electrical models is constructed. By employing deep learning algorithms and the robust nonlinear mapping ability of convolutional neural networks in the Pix2Pix generative adversarial network, we accelerate the intelligent inversion of the geological radar data on landslide susceptibility. This innovative approach effectively reconstructs hazard models, offering a reliable basis for interpretation of radar signals.

Molecular motor gliding motility assays based on myosin/actin or kinesin/microtubules are of interest for nanotechnology applications ranging from cargo-trafficking in lab-on-a-chip devices to novel biocomputation strategies. Prototype systems are typically monitored by expensive and bulky fluorescence microscopy systems. The development of integrated, direct electric detection of single filaments would strongly benefit applications and scale-up. We present estimates for the viability of such a detector by calculating the electrostatic potential change generated at a carbon nanotube transistor by a motile actin filament or microtubule under realistic gliding assay conditions. We combine this with detection limits based on previous state-of-the-art experiments using carbon nanotube transistors to detect catalysis by a bound lysozyme molecule and melting of a bound short-strand DNA molecule. Our results show that detection should be possible for both actin and microtubules using existing low ionic strength buffers given good device design, e.g., by raising the transistor slightly above the guiding channel floor. We perform studies as a function of buffer ionic strength, height of the transistor above the guiding channel floor, presence/absence of the casein surface passivation layer for microtubule assays and the linear charge density of the actin filaments/microtubules. We show that detection of microtubules is a more likely prospect given their smaller height of travel above the surface, higher negative charge density and the casein passivation, and may possibly be achieved with the nanoscale transistor sitting directly on the guiding channel floor. [ABSTRACT FROM AUTHOR]

Heterotopic ossification (HO) denotes the presence of mature bone tissue in soft tissues or around joints. Inflammation is a key driver of traumatic HO, and macrophages play an important role in this process. Ethyl caffeate (ECF), a critical active compound found in Petunia, exerts significant anti-inflammatory effects. Herein, we established a mouse model of HO by transection of the Achilles tendon and back burn and found abundant macrophage infiltration in the early stage of HO, which decreased with time. In vitro and in vivo experiments indicated that ECF inhibited macrophage polarization, and mechanistic studies showed that it inhibited the SIRT1/NF-κB signalling pathway, thereby suppressing the release of downstream inflammatory cytokines. ECF reduced HO in mice, and its effect was comparable to indomethacin (INDO). In vitro studies revealed that ECF did not directly affect the mineralization of mesenchymal stem cells (MSCs) or osteogenic differentiation but inhibited these processes by reducing the level of inflammatory cytokines in the conditioned medium (CM). Thus, M1 macrophages may play a crucial role in the pathogenesis of HO, and ECF is a prospective candidate for the prevention of trauma-induced HO. Data availability: Data will be made available on request

Wear debris after total joint arthroplasty can attract the recruitment of macrophages, which release pro-inflammatory substances, triggering the activation of osteoclasts, thereby leading to periprosthetic osteolysis (PPOL) and aseptic loosening. However, the development of pharmacological strategies targeting osteoclasts to prevent periprosthetic osteolysis has not been fruitful. In this study, we worked toward researching the effects and mechanisms of a farnesyltransferase (FTase) inhibitor Lonafarnib (Lon) on receptor activator of nuclear factor κB (NF-κB) ligand (RANKL)-induced osteoclastogenesis and bone resorption, as well as the impacts of Lon on titanium particle-induced osteolysis. To investigate the impacts of Lon on bone resorption and osteoclastogenesis in vitro, bone marrow macrophages were incubated and stimulated with RANKL and macrophage colony-stimulating factor (M-CSF). The influence of Lon on osteolysis prevention in vivo was examined utilizing a titanium particle-induced mouse calvarial osteolysis model. The osteoclast-relevant genes expression was explored by real-time quantitative PCR. Immunofluorescence was used to detect intracellular localization of nuclear factor of activated T cells 1 (NFATc1). SiRNA silence assay was applied to examine the influence of FTase on osteoclasts activation. Related signaling pathways, including NFATc1 signaling, NF-κB, mitogen-activated protein kinases pathways were identified by western blot assay. Lon was illustrated to suppress bone resorptive function and osteoclastogenesis in vitro, and it also reduced the production of pro-inflammatory substances and prevented titanium particle-induced osteolysis in vivo. Lon decreased the expression of osteoclast-relevant genes and suppressed NFATc1 nuclear translocation and auto-amplification. Mechanistically, Lon dampened FTase, and inhibition of FTase reduced osteoclast formation by suppressing ERK signaling. Lon is a promising treatment option for osteoclast-related osteolysis diseases including periprosthetic osteolysis by targeted inhibition of FTase through suppressing ERK signaling.

Measuring the thermopower of a confined quantum system reveals important information about its excitation spectrum. Our simulations show how this kind of transport spectroscopy is able to extract a clear signal for the onset of Wigner localization in a nanowire segment. This demonstrates that thermopower measurements provide a tool for investigating complex many-body quantum effects, which is less intrusive than the usual charge-stability diagram as no high source-drain bias is required. While the effect is most pronounced for weak tunnel coupling and low temperatures, the excited states also significantly affect the thermopower spectrum at moderate temperature, adding distinct features to the characteristic thermopower lineshape. [ABSTRACT FROM AUTHOR]

Quantum dots are model systems for quantum thermoelectric behavior because of their ability to control and measure the effects of electron-energy filtering and quantum confinement on thermoelectric properties. Interestingly, nonlinear thermoelectric properties of such small systems can modify the efficiency of thermoelectric power conversion. Using quantum dots embedded in semiconductor nanowires, we measure thermovoltage and thermocurrent that are strongly nonlinear in the applied thermal bias. We show that most of the observed nonlinear effects can be understood in terms of a renormalization of the quantum-dot energy levels as a function of applied thermal bias and provide a theoretical model of the nonlinear thermovoltage taking renormalization into account. Furthermore, we propose a theory that explains a possible source of the observed, pronounced renormalization effect by the melting of Kondo correlations in the mixed-valence regime. The ability to control nonlinear thermoelectric behavior expands the range in which quantum thermoelectric effects may be used for efficient energy conversion. [ABSTRACT FROM AUTHOR]

Nanowire heterostructures are of special interest for band structure engineering due to an expanded range of defect-free material combinations. However, the higher degree of freedom in nanowire heterostructure growth comes at the expense of challenges related to nanowire-seed particle interactions, such as undesired composition, grading and kink formation. To better understand the mechanisms of kink formation in nanowires, we here present a detailed study of the dependence of heterostructure nanowire morphology on indium pressure, nanowire diameter, and nanowire density. We investigate InAs-InP-InAs heterostructure nanowires grown with chemical beam epitaxy, which is a material system that allows for very abrupt heterointerfaces. Our observations indicate that the critical parameter for kink formation is the availability of indium, and that the resulting morphology is also highly dependent on the length of the InP segment. It is shown that kinking is associated with the formation of an inclined facet at the interface between InP and InAs, which destabilizes the growth and leads to a change in growth direction. By careful tuning of the growth parameters, it is possible to entirely suppress the formation of this inclined facet and thereby kinking at the heterointerface. Our results also indicate the possibility of producing controllably kinked nanowires with a high yield. [ABSTRACT FROM AUTHOR]

Semiconductor billiards are often considered as ideal systems for studying dynamical chaos in the quantum mechanical limit. In the traditional picture, once the electron's mean free path, as determined by the mobility, becomes larger than the device, disorder is negligible and electron trajectories are shaped by specular reflection from the billiard walls alone. Experimental insight into the electron dynamics is normally obtained by magnetoconductance measurements. A number of recent experimental studies have shown these measurements to be largely independent of the billiard's exact shape, and highly dependent on sample-to-sample variations in disorder. In this paper, we discuss these more recent findings within the full historical context of work on semiconductor billiards, and offer strong evidence that small-angle scattering at the sub-100 nm length-scale dominates transport in these devices. This has important implications for the role these devices can play for experimental tests of ideas in quantum chaos. [ABSTRACT FROM AUTHOR]

Quantum dots are an important model system for thermoelectric phenomena, and may be used to enhance the thermal-to-electric energy conversion efficiency in functional materials, by tuning the Fermi energy relative to the dots' transmission resonances. It is therefore important to obtain a detailed understanding of a quantum dot's thermopower as a function of the Fermi energy. However, so far it has proven difficult to take the effects of interactions into account in the interpretation of experimental data. In this paper, we present detailed measurements of the thermopower of quantum dots defined in heterostructure nanowires. We show that the thermopower lineshape is described well by a Landauer-type transport model that uses as its input experimental values of the dot conductance, which contains information about interaction effects. [ABSTRACT FROM AUTHOR]