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Chiral materials are the focus of research in a variety of fields such as chiroptical sensing, biosensing, catalysis, and spintronics. Twisted two-dimensional (2D) materials are rapidly developing into a class of atomically thin chiral materials that can be effectively modulated through interlayer twist. However, chirality transfer in chiral 2D materials has not been reported. Here, we show that the chirality from the twist interface of graphene can directly transfer to achiral few-layer graphene and lead to a strong chiroptical response probed with circularly polarized Raman spectroscopy. Distinct Raman optical activity (ROA) for the interlayer shear modes in achiral few-layer graphene is observed, with the degree of polarization reaching as high as 0.5. These findings demonstrate the programmability of chiroptical response through stacking and twist engineering in 2D materials and offer insights into the transfer of chirality in atomically thin chiral materials for optical and electronic applications.
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CO2 electroreduction (CO2 R) operating in acidic media circumvents the problems of carbonate formation and CO2 crossover in neutral/alkaline electrolyzers. Alkali cations have been universally recognized as indispensable components for acidic CO2 R, while they cause the inevitable issue of salt precipitation. It is therefore desirable to realize alkali-cation-free CO2 R in pure acid. However, without alkali cations, stabilizing *CO2 intermediates by catalyst itself at the acidic interface poses as a challenge. Herein, we first demonstrate that a carbon nanotube-supported molecularly dispersed cobalt phthalocyanine (CoPc@CNT) catalyst provides the Co single-atom active site with energetically localized d states to strengthen the adsorbate-surface interactions, which stabilizes *CO2 intermediates at the acidic interface (pH=1). As a result, we realize CO2 conversion to CO in pure acid with a faradaic efficiency of 60 % at pH=2 in flow cell. Furthermore, CO2 is successfully converted in cation exchanged membrane-based electrode assembly with a faradaic efficiency of 73 %. For CoPc@CNT, acidic conditions also promote the intrinsic activity of CO2 R compared to alkaline conditions, since the potential-limiting step, *CO2 to *COOH, is pH-dependent. This work provides a new understanding for the stabilization of reaction intermediates and facilitates the designs of catalysts and devices for acidic CO2 R.
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BACKGROUND: Epilepsy is a neurological disorder characterized by recurrent seizures and is often unresponsive to current treatment options. Ferroptosis, a recently defined iron-dependent regulated cell death, has been suggested as a potential therapeutic target for epilepsy due to its association with oxidative stress. Additionally, circRNA SLC8A1 (circSLC8A1) has been implicated in various neurological disorders and oxidative stress-related diseases but its involvement in epilepsy progression, particularly in relation to ferroptosis and oxidative stress, remains unclear. METHODS: qRT-PCR, Western blot, IHC and ELISA assays were employed to validate the relative expression of targeted genes and proteins. The levels of ROS, iron, LOP and GSH were detected by commercial kits. RNA pull-down and RIP assays were employed to detect the interactions among circSLC8A1, FUS and ATF3. A rat epilepsy model was established for further in vivo confirmation. RESULTS AND CONCLUSION: In this study, we investigated the potential involvement of circSLC8A1 in epilepsy progression and its connection to ferroptosis and oxidative stress. Our findings demonstrate that circSLC8A1 triggers neuronal ferroptosis by stabilizing ATF3 mRNA expression through recruitment with FUS. The induced neuronal ferroptosis contributes to epilepsy progression. These results enhance our understanding of epilepsy pathogenesis and may provide insights for the development of novel therapeutic strategies.
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Epilepsia , Ferroptosis , Animales , Ratas , Epilepsia/genética , Ferroptosis/genética , Hipocampo , Hierro , Estabilidad del ARN , ARN Circular/genética , Proteína FUS de Unión a ARN/metabolismoRESUMEN
Nickel-rich layered electrode material has been attracting significant attention owing to its high specific capacity as a cathode for lithium-ion batteries. Generally, the high-nickel ternary precursors obtained by traditional coprecipitation methods are micron-scale. In this work, the submicrometer single-crystal LiNi0.8Co0.1Mn0.1O2 (NCM) cathode is efficiently prepared by electrochemically anodic oxidation followed by a molten-salt-assisted reaction without the need of extreme alkaline environments and complex processes. More importantly, when prepared under optimal voltage (10 V), single-crystal NCM exhibits a moderate particle size (â¼250 nm) and strong metal-oxygen bonds due to reasonable and balanced crystal nucleation/growth rate, which are conducive to greatly enhancing the Li+ diffusion kinetics and structure stability. Given that a good discharge capacity of 205.7 mAh g-1 at 0.1 C (1 C = 200 mAh g-1) and a superior capacity retention of 87.7% after 180 cycles at 1 C are obtained based on the NCM electrode, this strategy is effective and flexible for developing a submicrometer single-crystal nickel-rich layered cathode. Besides, it can be adopted to elevate the performance and utilization of nickel-rich cathode materials.
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Electrochemical CO2 reduction (CO2R) to ethylene and ethanol enables the long-term storage of renewable electricity in valuable multi-carbon (C2+) chemicals. However, carbon-carbon (C-C) coupling, the rate-determining step in CO2R to C2+ conversion, has low efficiency and poor stability, especially in acid conditions. Here we find that, through alloying strategies, neighbouring binary sites enable asymmetric CO binding energies to promote CO2-to-C2+ electroreduction beyond the scaling-relation-determined activity limits on single-metal surfaces. We fabricate experimentally a series of Zn incorporated Cu catalysts that show increased asymmetric CO* binding and surface CO* coverage for fast C-C coupling and the consequent hydrogenation under electrochemical reduction conditions. Further optimization of the reaction environment at nanointerfaces suppresses hydrogen evolution and improves CO2 utilization under acidic conditions. We achieve, as a result, a high 31 ± 2% single-pass CO2-to-C2+ yield in a mild-acid pH 4 electrolyte with >80% single-pass CO2 utilization efficiency. In a single CO2R flow cell electrolyzer, we realize a combined performance of 91 ± 2% C2+ Faradaic efficiency with notable 73 ± 2% ethylene Faradaic efficiency, 31 ± 2% full-cell C2+ energy efficiency, and 24 ± 1% single-pass CO2 conversion at a commercially relevant current density of 150 mA cm-2 over 150 h.
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The Leidenfrost effect describes a fascinating phenomenon in which a liquid droplet, when deposited onto a very hot substrate, will levitate on its own vapor layer and undergo frictionless movements. Driven by the significant implications for heat transfer engineering and drag reduction, intensive efforts have been made to understand, manipulate, and utilize the Leidenfrost effect on macrosized objects with a typical size of millimeters. The Leidenfrost effect of nanosized objects, however, remains unexplored. Herein, we report on an unprecedented Leidenfrost effect of single nanosized sulfur particles at room temperature. It was discovered when advanced dark-field optical microscopy was employed to monitor the dynamic sublimation process of single sulfur nanoparticles sitting on a flat substrate. Despite the phenomenological similarity, including the vapor-cushion-induced levitation and the extended lifetime, the Leidenfrost effect at the nanoscale exhibited two extraordinary features that were obviously distinct from its macroscopic counterpart. First, there was a critical size below which single sulfur nanoparticles began to levitate. Second, levitation occurred in the absence of the temperature difference between the nanoparticle and the substrate, which was barely possible for macroscopic objects and underscored the value of bridging the gap connecting the Leidenfrost effect and nanoscience. The sublimation-triggered spontaneous takeoff of single sulfur nanoparticles shed new light on its further applications, such as nanoflight.
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Sensitive detection of local acoustic vibrations at the nanometer scale has promising potential applications involving miniaturized devices in many areas, such as geological exploration, military reconnaissance, and ultrasound imaging. However, sensitive detection of weak acoustic signals with high spatial resolution at room temperature has become a major challenge. Here, we report a nanometer-scale system for acoustic detection with a single molecule as a probe based on minute variations of its distance to the surface of a plasmonic gold nanorod. This system can extract the frequency and amplitude of acoustic vibrations with experimental and theoretical sensitivities of 10 pm Hz-1/2 and 10 fm Hz-1/2, respectively. This approach provides a strategy for the optical detection of acoustic waves based on molecular spectroscopy without electromagnetic interference. Moreover, such a small nano-acoustic detector with 40-nm size can be employed to monitor acoustic vibrations or read out the quantum states of nanomechanical devices.
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Resonancia por Plasmón de Superficie , Vibración , Acústica , Nanotecnología/métodos , Resonancia por Plasmón de Superficie/métodos , TemperaturaRESUMEN
Nanoengineering of metal anode materials shows great potential for energy storage with high capacity. Zero-dimensional nanoparticles are conducive to acquire remarkable electrochemical properties in sodium-ion batteries (SIBs) because of their enlarged surface active sites. However, it is still difficult to fulfill the requirements of practical applications in batteries owing to the deficiency of efficient and scalable preparation approaches of high-performance metal electrode materials. Herein, an electrochemical cathodic corrosion method is proposed for the tunable preparation of nanostructured antimony (Sb) by the introduction of a surfactant, which can efficiently avoid the agglomeration of Sb atom clusters generated from the Zintl compound and further stacking into bulk during the electrochemical process. Subsequently, graphene as the support and conductive matrix is uniformly interspersed by generating Sb nanoparticles (Sb/Gr). Moreover, the reversible crystalline-phase evolution of Sb â NaSb âNa3Sb for Sb/Gr was studied by in situ X-ray diffraction (XRD). Benefiting from the interconnection of the conductive network, Sb/Gr anodes deliver a high capacity of 635.34 mAh g-1, a retained capacity of 507.2 mAh g-1 after 150 cycles at 0.1 C (1 C = 660 mAh g-1), and excellent rate performance with the capacities of 473.41 and 405.09 mAh g-1 at 2 and 5 C, respectively. The superior cycle stability with a capacity of 346.26 mAh g-1 is achieved after 500 cycles at 2 C. This electrochemical approach offers a new route toward developing metal anodes with designed nanostructures for high-performance SIBs.
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The LiNi1- x- yCo xAl yO2 (NCA)-layered materials are regarded as a research focus of power lithium-ion batteries (LIBs) because of their high capacity. However, NCA materials are still up against the defects of cation mixing and surface erosion of electrolytes. Herein, a novel design strategy is proposed to obtain a heterostructured cathode material with a high-capacity LiNi0.88Co0.09Al0.03O2 layer ( R3Ì m) core and a stable LiNi0.5Mn1.5O4-like spinel ( Fd3Ì m) shell, which is prepared through spontaneous redox reaction of the precursor with KMnO4 in an alkaline solution and subsequent calcination procedure. The structure, morphology, element distribution, and electrochemical performances of the as-prepared NCA are studied by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and electrochemical techniques. The results show that the LiNi0.5Mn1.5O4-like spinel ( Fd3Ì m) shell layer with a robust cubic close-packed crystal structure is uniformly adhered to the surface of the NCA and can availably suppress the side reactions with the electrolyte and surface-phase transformation, which will facilitate insertion/extraction of Li+ ions during cycling. Benefiting from the enhanced structural stability and improved kinetics, the heterostructured NCA delivers a better cycling performance. The discharge specific capacity is as high as 153.7 mA h g-1 at 10 C, and even at high charge voltage of 4.5 V, the capacity retention can still increase 11% at 1 C (200 mA g-1) after 100 cycles. Besides, the material exhibits a prominent thermal stability of 248 °C at 4.3 V. Therefore, this novel structure design strategy can contribute to the development and commercialization of high-performance cathode materials for power LIBs.