Dual-Atom Co/Ni Electrocatalyst Anchored at the Surface-Modified Ti3C2Tx MXene Enables Efficient Hydrogen and Oxygen Evolution Reactions.

Dual-atom catalytic sites on conductive substrates offer a promising opportunity for accelerating the kinetics of multistep hydrogen and oxygen evolution reactions (HER and OER, respectively). Using MXenes as substrates is a promising strategy for depositing those dual-atom electrocatalysts, if the efficient surface anchoring strategy ensuring metal-substrate interactions and sufficient mass loading is established. We introduce a surface-modification strategy of MXene substrates by preadsorbing L-tryptophan molecules, which enabled attachment of dual-atom Co/Ni electrocatalyst at the surface of Ti3C2Tx by forming N-Co/Ni-O bonds, with mass loading reaching as high as 5.6 wt %. The electron delocalization resulting from terminated O atoms on MXene substrates, N atoms in L-tryptophan anchoring moieties, and catalytic metal atoms Co and Ni provides an optimal adsorption strength of intermediates and boosts the HER and OER kinetics, thereby notably promoting the intrinsic activity of the electrocatalyst. CoNi-Ti3C2Tx electrocatalyst displayed HER and OER overpotentials of 31 and 241 mV at 10 mA cm-2, respectively. Importantly, the CoNi-Ti3C2Tx electrocatalyst also exhibited high operational stability for both OER and HER over 100 h at an industrially relevant current density of 500 mA cm-2. Our study provided guidance for constructing dual-atom active metal sites on MXene substrates to synergistically enhance the electrochemical efficiency and stability of the energy conversion and storage systems.

Ultra-high dielectric tuning performance and double-set resistive switching effect achieved on the Bi2NiMnO6 thin film prepared by sol-gel method.

With the development of mobile terminals, tunable capacitors for signal processing and memristors for calculation have received a lot of attention. Combining a tunable capacitor and a memristor can improve the performance of mobile terminals and reduce space requirements. In this article, we report on Bi2NiMnO6 (BNMO) films with high dielectric tuning and nonvolatile resistive switching (RS) effects. The BNMO films are fabricated by the sol-gel method and annealed at different temperatures. It exhibits a dielectric tunability of up to 92%. This high dielectric tunability may be attributed to the modulation of the interface dipole by the electric field. When an electric field is applied, the interface dipole of the BNMO film is far away from the interface of the BNMO, and then forms a conductive channel where anions and cations are mixed. The BNMO films are found to have a double-set type effect due to its dielectric tunability properties. This work introduces an ultra-high dielectric tuning material and a new type of RS effect on BNMO thin film, which can achieve tuning and memory behavior on a device.

Bilirubin enhances the activity of ASIC channels to exacerbate neurotoxicity in neonatal hyperbilirubinemia in mice.

Neonatal hyperbilirubinemia is a common clinical condition that can lead to brain encephalopathy, particularly when concurrent with acidosis due to infection, ischemia, and hypoxia. The prevailing view is that acidosis increases the permeability of the blood-brain barrier to bilirubin and exacerbates its neurotoxicity. In this study, we found that the concentration of the cell death marker, lactate dehydrogenase (LDH) in cerebrospinal fluid (CSF), is elevated in infants with both hyperbilirubinemia and acidosis and showed stronger correlation with the severity of acidosis rather than increased bilirubin concentration. In mouse neonatal neurons, bilirubin exhibits limited toxicity but robustly potentiates the activity of acid-sensing ion channels (ASICs), resulting in increases in intracellular Ca2+ concentration, spike firings, and cell death. Furthermore, neonatal conditioning with concurrent hyperbilirubinemia and hypoxia-induced acidosis promoted long-term impairments in learning and memory and complex sensorimotor functions in vivo, which are largely attenuated in ASIC1a null mice. These findings suggest that targeting acidosis and ASICs may attenuate neonatal hyperbilirubinemia complications.

Ferroelectric Diode Effect with Temperature Stability of Double Perovskite Bi2NiMnO6 Thin Films.

Double perovskite Bi2NiMnO6 (BNMO) thin films grown on p-Si (100) substrates with LaNiO3 (LNO) buffer layers were fabricated using chemical solution deposition. The crystal structure, surface topography, surface chemical state, ferroelectric, and current-voltage characteristics of BNMO thin films were investigated. The results show that the nanocrystalline BNMO thin films on p-Si substrates without and with LNO buffer layer are monoclinic phase, which have antiferroelectric-like properties. The composition and chemical state of BNMO thin films were characterized by X-ray photoelectron spectroscopy. In the whole electrical property testing process, when the BNMO/p-Si heterojunction changed into a BNMO/LNO/p-Si heterojunction, the diode behavior of a single diode changing into two tail to tail diodes was observed. The conduction mechanism and temperature stability were also discussed.

[The reverse effects of allitridum on sodium current decrease caused by SCN5A-F1473S mutation].

This study was designed to test the allitridum (All) activity in correction of sodium current decrease caused by SCN5A-F1473S mutation in HEK293 cells. The result may provide a theoretical basis for screening of new drugs in the treatment of Brugada syndrome. We transferred SCN5A-F1473S channel plasmids into HEK293 cells in a transient transfection. All was administrated acutely and chronically using extracellular irrigation flow and co-culture model. The concentration of All was 30 µmol·L(-1). We used whole cell patch clamp technique in voltage clamp mode to record current and gating kinetics. In order to explore the rescue function of All on decreased sodium peak current, we used confocal microscopy and Western blot to detect the expression of channel proteins in the cell membrane. We found a significant increase in sodium peak current of the 30 µmol·L(-1) All HEK293 cells (269.8 ± 16.6 pA/pF, P < 0.01), almost closed to the current density of the control group（298.2 ± 17.5 p A/p F, P < 0.01）. All allowed the steady-state inactivation of the channel to move toward a more positive direction (V(1/2, inact) returns to -79.5 ± 2.4 mV, P < 0.01). It also slowed the intermediate state inactivation of the channel (inactivation prolongated to 598.1 ± 22.6 ms, P < 0.01). Meanwhile, All increased distribution and expression of the channel protein in the cell membrane (compared to F1473S, P < 0.01). All caused an increase of current in SCN5A-F1473S mutation cells. We consider that the main mechanism may be related to the reduced channel inactivation by the drug with an improvement of the migration barrier of the mutational channel.