Engineering interfacial coupling between 3D net-like Ni3(VO4)2 ultrathin nanosheets and MoS2 on carbon fiber cloth for boostinghydrogen evolution reaction.

The use of cheap and efficient electrocatalyst for the production of hydrogen is the key to solving the current energy crisis. Herein, we used a two-step hydrothermal process to fabricate noble-metal-free 3D net-like Ni3(VO4)2 ultrathin nanosheets coupled with MoS2@CFC interface. Unlike the traditional two-dimensional composite materials, Ni3(VO4)2 ultrathin nanosheets intersect with MoS2 nanosheets grown on CFC in a 3D net-like structure (Ni3(VO4)2/MoS2@CFC). Due to the mutual combination of structures and the interfacial coupling cooperation effect between Ni3(VO4)2 nanosheet and MoS2@CFC, the catalytically active area was expanded, and the intrinsic activity toward HER was significantly improved. Ni3(VO4)2/MoS2@CFC showed high activity at the industrial temperature (75 °C), with an overpotential of 77 mV (10 mA/cm2) and a 65 mV/dec Tafel slope. This material showed good stability at 0.5 M H2SO4. This work provides a heterostructure scheme for the construction of a novel noble metal-free electrocatalyst to promote hydrogen evolution reaction.

Improvement of nickel-cobalt-based supercapacitors energy storage performance by modification of elements.

Hybrid supercapacitors have the advantages of fast charging and discharging and long service life, which are an efficient and practical energy storage device. Therefore, the design of hybrid supercapacitors is the focus of current research. In this paper, the silver modified spinel NiCo2S4 nanorods (Ag2S-NiCo2S4/CF) are synthesized by an efficient and economical method, which has excellent electrochemical performance. The Ag2S-NiCo2S4/CF shows a high specific capacity of 179.7 mAh g-1 at current density of 1 A g-1, and excellent rate capability (capacitance retention of ~87% at 20 A g-1). The corresponding Ag2S-NiCo2S4/CF//AC/CF hybrid supercapacitor is assembled by Ag2S-NiCo2S4/CF as the positive electrode, which can provide an energy density of 35.978 Wh kg-1 at a high-power density of 800 W kg-1 and has significant cyclic stability (~80% of the initial capacitor after ~9600 cycles). Therefore, Ag2S-NiCo2S4/CF material is a promising electrode material that can be applied to hybrid supercapacitors.

A Mini Review of the Preparation and Photocatalytic Properties of Two-Dimensional Materials.

The successful preparation and application of graphene shows that it is feasible for the materials with a thickness of a single atom or few atomic layers to exist stably in nature. These materials can exhibit unusual physical and chemical properties due to their special dimension effects. At present, researchers have made great achievements in the preparation, characterization, modification, and theoretical research of 2D materials. Because the structure of 2D materials is often similar, it has a certain degree of qualitative versatility. Besides, 2D materials often carry good catalytic performance on account of their more active sites and adjustable harmonic electronic structure. In this review, taking 2D materials as examples [graphene, boron nitride (h-BN), transition metal sulfide and so on], we review the crystal structure and preparation methods of these materials in recent years, focus on their photocatalyst properties (carbon dioxide reduction and hydrogen production), and discuss their applications and development prospects in the future.

Design of nickel cobalt molybdate regulated by boronizing for high-performance supercapacitor applications.

Nickel-cobalt-based molybdates have been intensively investigated because of their high theoretical specific capacitance and multifarious oxidation states. Here, we have successfully synthesized hierarchical structures (Ni3B/Ni(BO2)2@NixCoyMoO4) by boronizing NixCoyMoO4 nanosheets on flexible carbon cloth substrates. Benefitting from the synergistic effect among Ni3B, Ni(BO2)2 and NixCoyMoO4 in hybrid architectures, the electrode material possesses higher capacity of 394.7 mA h g-1 at 1 A g-1 and a good rate performance (309.5 mA h g-1 maintained at 20 A g-1). Then, a hybrid supercapacitor assembled with Ni3B/Ni(BO2)2@NixCoyMoO4 and activated carbon as the positive and the negative electrode, displays a high specific capacitance of 370.7 F g-1 at 1 A g-1 (210 F g-1 at 10 A g-1), a high voltage of 1.7 V, and a high energy density of 131.8 W h kg-1 at the power density of 800 W kg-1 (still 74.7 W h kg-1 maintained at 8000 W kg-1). This study widens the research scope of boronizing pseudocapacitance materials and reveals a high application potential of Ni3B/Ni(BO2)2@NixCoyMoO4 for energy storage devices in the future.

Overexpression of ARNT2 is associated with decreased cell proliferation and better prognosis in gastric cancer.

Aryl hydrocarbon-receptor nuclear translocator (ARNT2) is a member of the bHLH PAS (basic helix-loop-helix Period/ARNT/Single-minded) family of transcription factors. Recently, some studies indicate that ARNT2 is associated with the occurrence and development of carcinoma. However, its roles in gastric cancer (GC) remain unclear. In the present study, we found that ARNT2 expression level is lower in GC tissues compared with adjacent non-tumor tissues, and negatively correlated with depth of invasion of the tumor, differentiated degree, and poor survival of GC patients. Overexpression of ARNT2 inhibits cell proliferation. Furthermore, AKT pathway contributed to ARNT2 -mediated PC proliferation. Taken together, our results provide the first evidence that high expression of ARNT2 inhibited proliferation of GC cells and affected tumor aggressiveness in GC patients.

Effects of mutants in bHLH region on structure stability and protein-DNA binding energy in DECs.

The human DEC subfamily contains two highly conserved members belonging to basic helix-loop-helix (bHLH) transcription factors. This conserved family is spread widely among various species with the function of regulating various crucial molecular signaling pathways. Due to the significance of DECs for important biological processes, their relationship with diseases and the lack of experimentally proven structures, we have implemented a comparative modeling for the bHLH region of DECs as homodimers with themselves and heterodimers with HES-1. Three mutants with predicted roles in reducing intramolecular binding (H57A, R65A, and LL7879AA in DEC1 and LL7071AA in DEC2) were investigated on DEC monomers. Molecular dynamics (MD) simulations were also employed to evaluate the behavior of the mutant molecules in aqueous solution. The monomer was divided into subregions for accurate investigation. The fluctuation in the basic region of mutants was higher than that of wild-type molecules. The binding energy value between protein and DNA obviously increased in the homodimer harboring R65A mutants, which led to more unstable status between protein and DNA. Thus, the mutant R65A interfered DNA-binding affinity. A study on the spatial structures of wild-type and mutant DECs may facilitate functional prediction for mutation effects and dynamic behavior under various conditions and may ultimately help in targeted drug design.