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It is essential to develop high-performance hydrogen evolution reaction catalysts. Reducing the amount of precious metals is an effective approach to replace Pt-based catalyst. Here, an electrocatalyst of metallic iridium anchored on mesoporous carbon nanofibers (Ir-mCNFs) is reported. After optimized the nanostructure (pore-forming agent content) of Ir-mCNFs, at the current density of 10 mA cm-2, the overpotential reaches 28 and 39 mV in alkaline and acid medium. Moreover, the content of Ir in this catalyst is just around 6 wt%. In conclusion, this paper reports an effective precious metal based HER catalysts with a lower amount of rare metals.

Recently, the moire superlattice structure (MSS) has garnered increasing attention thanks to its extensive research potential in condensed matter physics. However, how to create MSSs on non-van der Waals crystal plates is still elusive. In the present study, we propose a new method to prepare MSSs on the MoO2 (010) surface by soaking MoO2 in sulfur vapour at high temperature. MoO2 is 2D non-layered materials and is prepared by annealing MoO3 with sulfur vapour at 500 °C. The torsional modulation between two stacked monolayers is periodic, which provides additional freedom to change the material properties. Under sulfur vapour, the surface atoms of MoO2 first change from monoclinic to tetragonal crystals, and the interlayer covalent bonds are broken at the same time. Then, the top layer and buffer layer atoms of MoO2 form the original MSS, and the top layer continue to rotate into different twisted angles. Our work provides some inspiration and reference to the preparation of MSSs on the surface of the other 2D non-van der Waals crystals. In addition, we further compared the wettability of MSS@MoO2 and ordinary MoO2 powder. The results show that the surface of MSS@MoO2 is strongly hydrophobic (approximately 140°), while that of ordinary MoO2 is superhydrophilic (4.3°). Our results suggest that MSSs may be a potential application to change the surface wettability of materials.

NEMO (NF-κB essential modulator) is one of the important regulatory subunits of the IκB kinase (IκK) complex that controls the activation of the NF-κB signaling pathway. Here, we have identified the homolog of NEMO from the pacific oyster Crassostrea gigas. CgNEMO harbors the conserved the IκK binding region, NEMO ubiquitin binding domain and Zinc finger domain. In terms of tissue distribution, CgNEMO is expressed in various tissues with an observed highest expression in the hemocytes. Furthermore, infection by two related Vibrio strains significantly increased CgNEMO expression in the hemocytes. Cell culture based luciferase reporter assays showed that CgNEMO activates the NF-κB reporter in a dose-pendent manner. Moreover, CgNEMO was also found to counter the IkB-dependent inhibitory effect on NF-κB activation, providing a plausible mechanism of NF-κB activation by CgNEMO. Meanwhile, site-directed mutagenesis demonstrated that the putative ubiquitination site K535 is required for the activation of NF-κB, implying that ubiquitination of NEMO may be involved in regulating its activity. Finally, RNAi mediated knockdown of CgNEMO in vivo significantly compromised the bacterial induction of key cytokines TNF-α and IL-17, strongly suggesting a role for CgNEMO in acute immune defense in oyster. In conclusion, this study provides new insights into our understanding about the evolution of NEMO mediated NF-κB activation and the induction of cytokine. Our findings may provide valuable information about diseases control and management in oyster aquaculture.

A homogeneous better-dispersed ultrathin nanosheets (ca. 5 nm) of cobalt-nickel layered double hydroxides (LDH) supported on nickel foam scaffold was synthesized using controllable electrodeposition approach for high efficiency electrode materials of new supercapacitor. The morphology and electrochemical performances of the samples can be controlled by adjusting the precursor ratio, i.e., Ni(OAc)2/Co(NO3)2 molar ratio in the electrodeposition approach. With the increase of this molar ratio, the electrochemical performances give a volcano trend. When the optimized molar ratio is 0.64/0.36, the hybrid delivered a high specific capacitance of 1587.5 F g−1 at a current density of 0.5 A g−1, with good rate capability (1155 F g−1 was retained even at 10 A g−1) and a robust recycle stability (remaining 91.5% after 1000 cycles at 5 A g−1). The good performance could be attributed to the enlarged interlayer spacing, ultrathin nanosheets and synergistic effects between Co(OH)2 and Ni(OH)2. Furthermore, an asymmetric supercapacitor with a high energy density of 34.5 Wh kg−1 at 425 W kg−1 and excellent cycling stability of 85.4% after 5000 charge-discharge cycles at 2 A g−1 was fabricated. We believe that this fantabulous new electrode material would have encouraging applications in electrochemical energy storage and a wide readership.

In bivalve mollusks, circulating hemocyte mediated phagocytosis is one of the primary ways to eliminate invading microbes. Here, we have identified one CgLRFN (leucine-rich repeat and fibronectin type-III domain-containing protein) in the Crassostrea gigas as a novel transmembrane LRR (Leucine-rich repeat) domain containing protein in C. gigas, homologous to the jawless fish VLR protein, that plays an important role in recognizing bacteria and promoting hemocytic phagocytosis. Tissue distribution analysis of CgLRFN in Pacific oyster showed that it is widely expressed in various tissues like the gills, adductor muscles, digestive glands, gonads, heart and in the hemocytes. Furthermore, infection of Pacific oysters with two marine Vibrio strains V. alginolyticus and V. parahaemolyticus was found to significantly increase CgLRFN expression in the hemocytes. Analysis of subcellular localization showed that CgLRFN is primarily localized in the cell membrane. Additionally, CgLRFN was found to be able to bind both the bacterial strains, indicating its possible role as a cell surface receptor. Flow cytometry analysis revealed that CgLRFN coated bacteria was phagocytosed by oyster hemocytes at a significantly higher rate compared to the uncoated bacteria. Finally, RNAi mediated knockdown of CgLRFN in vivo resulted in reduced clearance of both the bacterial strains from the oyster hemolymph. Overall, our study demonstrates that CgLRFN acts as a pattern recognition receptor for Vibrio spp. and promotes hemocytic phagocytosis in the Pacific oyster, which is critical for understanding the mechanism of bacterial infection in lower invertebrates, and also contributes to disease management of this economically and ecologically important marine mollusk.

The defects in perovskite crystals and the penetration of moisture/oxygen into the perovskite layer are major problems for perovskite solar cells (PSCs) to achieve long-term stability and high power conversion efficiency (PCE). However, there is still a lack of multifunctional passivation materials to solve these problems. Herein, for the first time, we report oleyl amine-coated PbSO4(PbO)4 quantum-dots (QDs), as a passivation material with dual functions to simultaneously passivate the surface defects and block the penetration of moisture/oxygen into the perovskite layer for stable and efficient PSCs. The PbSO4(PbO)4 QDs significantly reduce the defect density of the as-prepared CH3NH3PbI3 films by passivating under-coordinated Pb ions and I anions and effectively enhance charge extraction efficiency at the TiO2/CH3NH3PbI3 and CH3NH3PbI3/spiro-OMeTAD interfaces. Moreover, the hydrogen bond between H atoms of the OA and I atoms of the perovskite and the interface electric field at CH3NH3PbI3/OA interface also contribute to the improvement of efficiency and stability of PSCs. Finally, higher PCE (20.02%) is achieved by the PSCs with OA-coated PbSO4(PbO)4 QDs compared to that (16.86%) of the PSCs without OA-coated PbSO4(PbO)4, corresponding to a 18.7% enhancement. Moreover, the PSCs with OA-coated PbSO4(PbO)4 QDs maintain 90% of initial efficiency after operation for 280 h, indicating better stability than the PSCs without PbSO4(PbO)4 QDs.

Hollow and porous nanostructures have attracted a great deal of attention because of their widespread potential applications, and nanostructures with tunable size are desirable to optimize their properties. Therefore, simple and high yield methods for preparation of nanostructures with tunable sizes have been regarded as pursuing objects. Herein, we report a novel simple method for large scale synthesis of porous ZnO hollow structures with tunable diameters and shell thicknesses. The novel synthesis strategy involves oxidizing Zn spheres and polyhedrons in solid state to form a thin ZnO layer on the surface under low temperature, followed by removal of the Zn cores upon heating. Noticeably, not only can the diameter and shell thickness be respectively tuned, but also the shell thickness can be also easily controlled because of its slow oxidation rate in a solid-phase diffusion process under low temperature. It is obvious that this novel simple method involved here can readily be extended to other metal oxide systems.