Doping Ru on FeNi LDH/FeII/III-MOF heterogeneous core-shell structure for efficient oxygen evolution.

Noble metal-based catalysts such as RuO2 and IrO2 are widely used in the catalysis of the OER. However, because of their high price and poor stability, it is urgent to develop transition metal-based electrocatalysts with low precious metal doping as an alternative. Layered double hydroxides (LDHs) grown on 3D metal-organic frameworks (MOFs) are ideal for doping precious metals owing to abundant defects at the heterointerface, large surface area, and intrinsic oxygen evolution activity. In this study, a novel FeNi LDH/MOF heterostructure was prepared via a two-step solvothermal method using Fe-soc-MOFs as the substrate. Subsequently, Ru was introduced through a hydrothermal process. The as-synthesized Ru@FeNi LDH/MOF has an overpotential of only 242 mV at a current density of 10 mA cm-2 and can be used in continuous electrolysis for 48 h. Its unique nanocubic core-shell structure and flower-like LDHs on its surface provide a large number of active sites, which become the key to ensuring high activity and stability. With the doping of Ru, the electronic structure was adjusted and electron transfer was accelerated, further improving electrochemical activity. This study provides a new idea for developing transition metal-based catalysts with low noble metal loading.

Fe-Based Metal Organic Framework-Derived FeNiP/N-Doped Carbon Heterogeneous Core-Shell Structures for Oxygen Evolution.

It is of great significance to explore high activity, low overpotential, and outstanding durability electrocatalysts without precious metals for oxygen evolution reaction to reduce the energy consumption in the electrolysis of water to product hydrogen. Metal organic frameworks (MOFs) with periodic structure and uniform pore distribution have been widely used as precursors for the synthesis of transition metal electrocatalysts. Herein, we first synthesized nanoscale Fe-soc-MOFs with relatively high specific surface area and in situ converted it into nickel-iron double layer hydroxide/MOF (FeNi LDH/MOF) by Ni2+ etching. Finally, a nickel-iron phosphide/nitrogen-doped carbon cubic nanocage (FeNiP/NC) was obtained by calcination and phosphating. FeNiP/NC with its unique core-shell structure has an overpotential of only 240 mV at a current density of 10 mA/cm2 and can be continuously electrolyzed for 45 h. High catalytic activity of FeNiP/NC is mainly attributed to the action of Fe and Ni bimetals and the synergistic effect between FeNiP and N-doped porous carbon, which was confirmed by the calculation of density functional theory (i.e., Gibbs free energy). After a long period of electrolysis, FeNiP was converted to MOOH (M = Fe and Ni) and became the new active site. This study provides a feasible optimization strategy for the development of high-efficiency three-dimensional electrode materials without precious metals.

Construction and characterization of Aeromonas hydrophila crp and fur deletion mutants and evaluation of its potential as live-attenuated vaccines in crucian carp.

Aeromonas hydrophila (A. hydrophila) is a typical zoonotic pathogenic bacterium that infects humans, animals, and fish. It has been reported that the Fur, a Fe2+ regulatory protein, and the Crp, a cAMP receptor protein, play important roles in bacterial virulence in many bacteria, but no research has been investigated on A. hydrophila. In this study, the Δfur and Δcrp mutant strains were constructed by the suicide plasmid method. These two mutant strains exhibited a slightly diminished bacterial growth and also were observed some alterations in the number of outer membrane proteins, and the disappearance of hemolysis in the Δcrp strain. Animal experiments of crucian carp showed that the Δfur and Δcrp mutant strains significantly decreased virulence compared to the wild-type strain, and both mutant strains were able to induce good immune responses by two kinds of administration routes of intraperitoneal immunization (i.p) and immersion immunization, and the protection rates through intraperitoneal injection of Δfur and Δcrp to crucian carp were as high as 83.3 % and 73.3 %, respectively, and immersion immunization route of Δfur and Δcrp to crucian carp provided protection as high as 40 % and 20 %, respectively. These two mutant strains showed abilities to induce changes in enzymatic activities of the non-specific enzymes SOD, LZM, AKP, and ACP in crucian carp. Together, these results indicated the Δfur and Δcrp mutants were safe and effective candidate vaccine strains, showing good protection against the wild-type A. hydrophila challenge.

Impact of the National Wetland Park in the Poyang Lake Area on Oncomelania hupensis, the Intermediate Host of Schistoma japonicum.

In this study, we aimed to understand the influence of ecotourism on the distribution of Oncomelania hupensis and to provide a scientific basis for formulating effective snail control methods in tourism development areas. Poyang Lake National Wetland Park was selected as the pilot area, and sampling surveys were conducted based on comprehensive and detailed investigations of all historical and suspected snail environments according to map data to determine the snail distribution and analyze the impact of tourism development. The results showed that from 2011 to 2021, the positive rates of blood tests and fecal tests tended to decrease among residents of the Poyang Lake area. The positive rates of blood tests and fecal tests in livestock also tended to decrease. The average density of O. hupensis snails decreased, and no schistosomes were detected during infection monitoring in Poyang Lake. The local economy rapidly grew after the development of tourism. The development of ecotourism projects in Poyang Lake National Wetland Park increased the transfer frequency of boats, recreational equipment, and people, but it did not increase the risk of schistosomiasis transmission or the spread of O. hupensis snails. Prevention and monitoring only need to be strengthened in low-endemic schistosomiasis areas to effectively promote economic development due to tourism activities without affecting the health of residents.

Gene expression profile-based drug screen identifies SAHA as a novel treatment for NAFLD.

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide. Being part of the metabolic syndrome, NAFLD is characterized by the deposition of triglycerides (TGs) as lipid droplets in the cytoplasm of hepatic cells. Recently, the rapid development of high-throughput genome analysis technologies provided opportunities to screen for new drugs for NAFLD. In this study, we screened for potential drugs based on the gene expression profiles of 73 compounds and identified histone deacetylase (HDAC) inhibitors as a novel treatment for the accumulation of lipids in hepatocytes. In the subsequent analysis and experiments, we discovered that SAHA inhibited the fatty acid and lipid metabolism pathways in hepatic cells and induced a significant deficiency of lipid accumulation in HepG2 and SMMC-7721 cells. Furthermore, SAHA inhibited lipid synthesis in hepatic cells by directly suppressing the expression of DGAT2. Hence, our study provides a novel method to screen for effective drugs for liver diseases and identifies SAHA as a potent treatment for NAFLD.