Promoted Overall Water Splitting Catalytic Activity and Durability of Ni3Fe Alloy by Designing N-Doped Carbon Encapsulation.

Combining an electrochemically stable material onto the surface of a catalyst can improve the durability of a transition metal catalyst, and enable the catalyst to operate stably at high current density. Herein, the contribution of the N-doped carbon shell (NCS) to the electrochemical properties is evaluated by comparing the characteristics of the Ni3Fe@NCS catalyst with the N-doped carbon shell, and the Ni3Fe catalyst. The synthesized Ni3Fe@NCS catalyst has a distinct overpotential difference from the Ni3Fe catalyst (ηOER = 468.8 mV, ηHER = 462.2 mV) at (200 and -200) mA cm-2 in 1 m KOH. In stability test at (10 and -10) mA cm-2, the Ni3Fe@NCS catalyst showed a stability of (95.47 and 99.6)%, while the Ni3Fe catalyst showed a stability of (72.4 and 95.9)%, respectively. In addition, the in situ X-ray Absorption Near Edge Spectroscopy (XANES) results show that redox reaction appeared in the Ni3Fe catalyst by applying voltages of (1.7 and -0.48) V. The decomposition of nickel and iron due to the redox reaction is detected as a high ppm concentration in the Ni3Fe catalyst through Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) analysis. This work presents the strategy and design of a next-generation electrochemical catalyst to improve the electrocatalytic properties and stability.

Exploring Oxygen Vacancy Effect in 1D Structural SnIP for CO2 Electro-Reduction to Formate.

1D nanostructures exhibit a large surface area and a short network distance, facilitating electron and ion transport. In this study, a 1D van der Waals material, tin iodide phosphide (SnIP), is synthesized and used as an electrocatalyst for the conversion of CO2 to formate. The electrochemical treatment of SnIP reconstructs it into a web-like structure, dissolves the I and P components, and increases the number of oxygen vacancies. The resulting oxygen vacancies promote the activity of the CO2 reduction reaction (CO2RR), increasing the local pH of the electrode surface and maintaining the oxidative metal site of the catalyst despite the electrochemically reducing environment. This strategy, which stabilizes the oxidation state of the catalyst, also helps to improve the durability of CO2RR. In practice, 1D structured SnIP catalyst exhibits outstanding performance with >92% formate faradaic efficiency (FEformate) at 300 mA cm-2, a maximum partial current density for formate of 343 mA cm-2, and excellent long-term stability (>100 h at 100 mA cm-2 with >86% FEformate). This study introduced a method to easily generate oxygen vacancies on the catalyst surface by utilizing 1D materials and a strategy to improve the durability of CO2RR by stabilizing the oxidation state of the catalyst.

Sp1 facilitates continued HSV-1 gene expression in the absence of key viral transactivators.

Productive replication of herpes simplex virus (HSV) relies upon a well-ordered transcriptional cascade flowing from immediate-early (IE) to early (E) to late (L) gene products. While several virus-encoded transcriptional activators are involved in this process, IE and E gene promoters also contain multiple binding sites for the ubiquitously expressed cellular transcription factor Sp1. Sp1 has been previously implicated in activating HSV-1 gene transcription downstream of these sites, but why Sp1-binding sites are maintained in the promoters of genes activated by virus-encoded activators remains unclear. We hypothesized that Sp1 enables continued HSV-1 transcription and replication when viral transactivators are limited. We used a depletion-based approach in human foreskin fibroblasts to investigate the specific contribution of Sp1 to the initiation and progression of the HSV-1 lytic gene cascade. We found that Sp1 increased viral transcript levels, protein expression, and replication following infection with VP16- or ICP0-deficient viruses but had little to no effect on rescued viruses or during wild-type (WT) HSV-1 infection. Moreover, Sp1 promoted WT virus transcription and replication following interferon treatment of fibroblasts and thus may contribute to viral immune evasion. Interestingly, we observed reduced expression of Sp1 and Sp1-family transcription factors in differentiated sensory neurons compared to undifferentiated cells, suggesting that reduced Sp1 levels may also contribute to HSV-1 latent infection. Overall, these findings indicate that Sp1 can promote HSV-1 gene expression in the absence of key viral transactivators; thus, HSV-1 may use Sp1 to maintain its gene expression and replication under adverse conditions.IMPORTANCEHerpes simplex virus (HSV) is a common human pathogen that actively replicates in the epithelia but can persist for the lifetime of the infected host via a stable, latent infection in neurons. A key feature of the HSV replication cycle is a complex transcriptional program in which virus and host-cell factors coordinate to regulate expression of the viral gene products necessary for continued viral replication. Multiple binding sites for the cellular transcription factor Sp1 are located in the promoters of HSV-1 genes, but how Sp1 binding contributes to transcription and replication of wild-type virus is not fully understood. In this study, we identified a specific role for Sp1 in maintaining HSV-1 gene transcription under adverse conditions, as when virus-encoded transcriptional activators were absent or limited. Preservation of Sp1-binding sites in HSV-1 gene promoters may thus benefit the virus as it navigates diverse cell types and host-cell conditions during infection.

Extrinsic hydrophobicity-controlled silver nanoparticles as efficient and stable catalysts for CO2 electrolysis.

To realize economically feasible electrochemical CO2 conversion, achieving a high partial current density for value-added products is particularly vital. However, acceleration of the hydrogen evolution reaction due to cathode flooding in a high-current-density region makes this challenging. Herein, we find that partially ligand-derived Ag nanoparticles (Ag-NPs) could prevent electrolyte flooding while maintaining catalytic activity for CO2 electroreduction. This results in a high Faradaic efficiency for CO (>90%) and high partial current density (298.39 mA cm‒2), even under harsh stability test conditions (3.4 V). The suppressed splitting/detachment of Ag particles, due to the lipid ligand, enhance the uniform hydrophobicity retention of the Ag-NP electrode at high cathodic overpotentials and prevent flooding and current fluctuations. The mass transfer of gaseous CO2 is maintained in the catalytic region of several hundred nanometers, with the smooth formation of a triple phase boundary, which facilitate the occurrence of CO2RR instead of HER. We analyze catalyst degradation and cathode flooding during CO2 electrolysis through identical-location transmission electron microscopy and operando synchrotron-based X-ray computed tomography. This study develops an efficient strategy for designing active and durable electrocatalysts for CO2 electrolysis.

Neuronal miR-9 promotes HSV-1 epigenetic silencing and latency by repressing Oct-1 and Onecut family genes.

Herpes simplex virus 1 (HSV-1) latent infection entails repression of viral lytic genes in neurons. By functional screening using luciferase-expressing HSV-1, we identify ten neuron-specific microRNAs potentially repressing HSV-1 neuronal replication. Transfection of miR-9, the most active candidate from the screen, decreases HSV-1 replication and gene expression in Neuro-2a cells. Ectopic expression of miR-9 from lentivirus or recombinant HSV-1 suppresses HSV-1 replication in male primary mouse neurons in culture and mouse trigeminal ganglia in vivo, and reactivation from latency in the primary neurons. Target prediction and validation identify transcription factors Oct-1, a known co-activator of HSV transcription, and all three Onecut family members as miR-9 targets. Knockdown of ONECUT2 decreases HSV-1 yields in Neuro-2a cells. Overexpression of each ONECUT protein increases HSV-1 replication in Neuro-2a cells, human induced pluripotent stem cell-derived neurons, and primary mouse neurons, and accelerates reactivation from latency in the mouse neurons. Mutagenesis, ChIP-seq, RNA-seq, ChIP-qPCR and ATAC-seq results suggest that ONECUT2 can nonspecifically bind to viral genes via its CUT domain, globally stimulate viral gene transcription, reduce viral heterochromatin and enhance the accessibility of viral chromatin. Thus, neuronal miR-9 promotes viral epigenetic silencing and latency by targeting multiple host transcription factors important for lytic gene activation.

Scalable Fabrication of Quasi-One-Dimensional van der Waals Ta2Pt3Se8 Nanowire Thin Films via Solution Processing for NO2 Gas Sensing over Large Areas.

Solution-based processing of van der Waals (vdW) one- (1D) and two-dimensional (2D) materials is an effective strategy to obtain high-quality molecular chains or atomic sheets in a large area with scalability. In this work, quasi-1D vdW Ta2Pt3Se8 was exfoliated via liquid phase exfoliation (LPE) to produce a stably dispersed Ta2Pt3Se8 nanowire solution. In order to screen the optimal exfoliation solvent, nine different solvents were employed with different total surface tensions and polar/dispersive (P/D) component (P/D) ratios. The LPE behavior of Ta2Pt3Se8 was elucidated by matching the P/D ratios between Ta2Pt3Se8 and the applied solvent, resulting in N-methyl-2-pyrrolidone (NMP) as an optimal solvent owing to the well-matched total surface tension and P/D ratio. Subsequently, Ta2Pt3Se8 nanowire thin films are manufactured via vacuum filtration using a Ta2Pt3Se8/NMP dispersion. Then, gas sensing devices are fabricated onto the Ta2Pt3Se8 nanowire thin films, and gas sensing property toward NO2 is evaluated at various thin-film thicknesses. A 50 nm thick Ta2Pt3Se8 thin-film device exhibited a percent response of 25.9% at room temperature and 32.4% at 100 °C, respectively. In addition, the device showed complete recovery within 14.1 min at room temperature and 3.5 min at 100 °C, respectively.

Proton-Coupled Electron Transfer on Cu2O/Ti3C2Tx MXene for Propane (C3H8) Synthesis from Electrochemical CO2 Reduction.

Electrochemical CO2 reduction reaction (CO2RR) to produce value-added multi-carbon chemicals has been an appealing approach to achieving environmentally friendly carbon neutrality in recent years. Despite extensive research focusing on the use of CO2 to produce high-value chemicals like high-energy-density hydrocarbons, there have been few reports on the production of propane (C3H8), which requires carbon chain elongation and protonation. A rationally designed 0D/2D hybrid Cu2O anchored-Ti3C2Tx MXene catalyst (Cu2O/MXene) is demonstrated with efficient CO2RR activity in an aqueous electrolyte to produce C3H8. As a result, a significantly high Faradaic efficiency (FE) of 3.3% is achieved for the synthesis of C3H8 via the CO2RR with Cu2O/MXene, which is ≈26 times higher than that of Cu/MXene prepared by the same hydrothermal process without NH4OH solution. Based on in-situ attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) and density functional theory (DFT) calculations, it is proposed that the significant electrocatalytic conversion originated from the synergistic behavior of the Cu2O nanoparticles, which bound the *C2 intermediates, and the MXene that bound the *CO coupling to the C3 intermediate. The results disclose that the rationally designed MXene-based hybrid catalyst facilitates multi-carbon coupling as well as protonation, thereby manipulating the CO2RR pathway.

Tailoring Contacts for High-Performance 1D Ta2Pt3S8 Field-Effect Transistors.

Materials with van der Waals (vdW) unit structures rely on weak interunit vdW forces, facilitating physical separation and advancing nanomaterial research with remarkable electrical properties. Recently, there has been growing interest in one-dimensional (1D) vdW materials, celebrated for their advantageous properties, characterized by reduced dimensionality and the absence of dangling bonds. In this context, we synthesize Ta2Pt3S8, a 1D vdW material, and assess its suitability for field-effect transistor (FET) applications. Spectroscopic analysis and electrical characterization confirmed that the band gap and work function of Ta2Pt3S8 are 1.18 and 4.77 eV, respectively. Leveraging various electrode materials, we fabricated n-type FETs based on Ta2Pt3S8 and identified Cr as the optimal electrode, exhibiting a high mobility of 57 cm2 V-1 s-1. In addition, we analyzed the electron transport mechanism in n-type FETs by investigating Schottky barrier height, Schottky barrier tunneling width, and contact resistance. Furthermore, we successfully fabricated p-type operating Ta2Pt3S8 FETs using a molybdenum trioxide (MoO3) layer as a high work function contact electrode. Finally, we achieved Ta2Pt3S8 nanowire rectifying diodes by creating a p-n junction with asymmetric contact electrodes of Cr and MoO3, demonstrating an ideality factor of 1.06. These findings highlight the electronic properties of Ta2Pt3S8, positioning it as a promising 1D vdW material for future nanoelectronics and functional vdW-based device applications.