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Purpose Nitrification inhibitor plays an important regulatory role in inhibiting the nitrification of ammonium in soils. However, most of nitrification inhibitors lack the sustainable effects in suppressing the nitrification of ammonium. In this study, a novel DMS nitrification inhibitor was prepared and tested to explore its lasting effect of nitrification suppression in black soil. Materials and methods Both culture experiments and field trial were performed in black soils. Three kinds of nitrification inhibitors (NIs), dicyandiamide (DCD) with low bioactivity, 3,4-dimethylpyrazole phosphate (DMPP) with high bioactivity, and a novel 3,4-dimethylpyrazole sulfate zinc (DMS) with long half-life, were applied into soils, respectively, and the abundance changes of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) were investigated; then, the accumulation changes of inorganic nitrogen, nitrogen use efficiency, and crop yields were furtherly evaluated. Results and discussions A novel DMS nitrification inhibitor with high activity and long half-life maintained a persistent effect of nitrification suppression, and remarkably increased the accumulation of ammonium nitrogen in soil, thus improving nitrogen use efficiency and crop yields. This study implies that lowering the nitrogen loss of nitrification-triggered in soil is of great importance for improving nitrogen use efficiency. Conclusions This study provided an insight into the sustainable nitrification suppression of a novel DMS nitrification inhibitor under excessive application of nitrogen fertilizer in black soils. Compared with improving the activity, reasonably prolonging the validity of nitrification inhibitors in soil is a more important strategy increasing the sustainable effects of nitrification inhibition, and the survival period of nitrification inhibitors in soil should be a crucial factor improving nitrogen use efficiency.

Cancer cell-derived extracellular vesicles (EVs) have extensive application in the formation of their environment, including metastasis. This study explored the ability of gastric cancer (GC) cell-derived EVs-mediated microRNA-129-5p/E2F transcription factor 7/mitogen-activated protein kinase/extracellular regulated protein kinase (miR-129-5p/E2F7/MAPK/ERK) axis to affect the peritoneal metastasis of GC by delivering lncRNA small nucleolar RNA host gene 12 (SNHG12). EV-derived lncRNA and SNHG12/miR-129-5p/E2F7 network were determined by bioinformatics analysis. The regulatory relationship among SNHG12, miR-129-5p, and E2F7 was verified using a combination of dual-luciferase reporter gene, RNA immunoprecipitation, and RNA pull-down assays. The SNHG12, miR-129-5p, and E2F7 expression was measured by RT-qPCR. After GC cell-derived EVs were isolated and co-cultured with human peritoneal mesothelial cells (HPMCs), the uptake of EVs by HPMCs was observed under laser scanning confocal microscopy. Cell viability and apoptosis were examined using cell counting kit-8 and flow cytometry, respectively. Western blot analysis was performed to measure the mesothelial–mesenchymal transition (MMT)-related protein expression. The pathological and morphological characteristics of metastatic tumors in nude mice were observed by hematoxylin–eosin staining. A high SNHG12 expression was correlated with the poor prognosis of patients with GC. GC-derived EVs led to increased HPMC apoptosis and MMT by transferring SNHG12, whereas the knockdown of SNHG12 annulled the aforementioned results. SNHG12 sponged miR-129-5p to boost E2F7 expression and activate the MAPK/ERK signaling, thus inducing HPMC apoptosis and MMT. In vivo experiments further verified that EVs derived from GC cells promoted peritoneal metastasis in nude mice. GC cell-derived EVs elevated the E2F7 expression and activated the MAPK/ERK signaling to promote peritoneal metastasis through the delivery of SNHG12.

In this work, PtCo nanoparticles (NPs) on hierarchically ordered mesoporous carbon (PtCo/OMC) are synthesized for polymer electrolyte membrane fuel cells (PEMFCs) aiming to improve the activity and durability of the Pt-based catalyst towards oxygen reduction reaction (ORR). Specifically, the OMC is prepared through a solvent evaporation-induced self-assembly (EISA) method by using a triblock copolymer PEO-PPO-PEO as the structure agent, followed by annealing in the nitrogen atmosphere to decompose the structure agent and to carbonize the carbon precursor. PtCo nanoparticles (NPs) are fabricated with an average diameter of 3.3 nm by H2 reduction and galvanic replacement in an acid solution, and then are uniformly dispersed onto the OMC via impregnation. The typical mesoporous structure of the OMC enhances the uniformly distribution and thermal stability of the small-sized PtCo NPs. The activity and the durability of the as-prepared PtCo/OMC catalyst are investigated by cyclic voltammetry (CV) and single-cell test. In the electrochemical tests, PtCo/OMC exhibits a high ECSA value of 88.56 m2g−1, and a ECSA retention of 77.5% after 5000 CV cycles. The results show that the PtCo/OMC catalyst is more active and more stable than the commercial-carbon-supported PtCo catalyst (PtCo/XC-72). PtCo nanoparticles (NPs) on hierarchically ordered mesoporous carbon (PtCo/OMC) are synthesized aiming to improve the activity and stability of the Pt-based catalyst for the oxygen reduction reaction (ORR). Due to the natural mesoporous and graphite-carbon nanostructure of the OMC, the as-prepared PtCo/OMC catalyst is more active and more stable than the PtCo NPs on the commercial Vulcan@ XC-72 support (PtCo/XC-72), showing great potential in proton exchange membrane fuel cells (PEMFCs).

A series of Ni-modified Mo2C catalysts with La2O3-stabilized ZrO2 supports were synthesized via template method coupled with incipient wetness impregnation and temperature-programmed carbonization. The catalyst was tested in dry reforming of methane (DRM) reaction at the temperature range from 973 to 1173 K in a fixed-bed quartz reactor under atmospheric pressure. XRD, Raman, BET, H2-TPD, SEM, EDS and TEM were conducted to characterize the phase constitution, the pore structure, the morphology and the crystal structure of the catalysts. Ni–Mo2C nanoparticles of ~ 3 nm diameter were obtained for these catalysts, and the La2O3–ZrO2 supports exhibited a cubic lattice structure with a sheet shape, which is believed to contain an abundant of oxygen vacancies. And the synergistic interaction between the oxygen vacancy in La–Zr–O solid solution and the Ni–Mo2C particles could decrease the apparent activation energy of CO2. Both of them are beneficial for accelerating DRM reaction. CH4 conversion of the best specimen catalyst reaches 94% at 1173 K, and the catalyst maintains its stability after 100-h reaction. The superior catalytic activity of NMLZ-7.5 is attributed to the improved BET surface area (33.2 m2/g), smaller crystallites, grain boundaries and oxidation–carbonization cycle of Ni–Mo2C.

This work offers an effective size-controlled synthesis of platinum nanoparticle (Pt NP) arrays for electrocatalyst through self-assembled nanopatterns of block copolymers on titanium (Ti) wafers. Size, spacing and uniformity of Pt NP with loading of Pt to a minimum were investigated to be controlled and adjusted in order to improve the electrochemically active surface area (ECSA) and ECSA stability, and Pt concentration in copolymer/chloroplatinic acid (H2PtCl6) solution was verified to be one of the most important factors to control the arrays’ structure. In our case, the Pt NPs with predictable size of 5–16.5 nm could be obtained when the Pt concentration is larger than 0.05 mg ml−1, which the dominant diameter is proved to be proportional to one-third power of the Pt concentration according to the linear relation of templates’ Pt/N mass ratio versus Pt concentration, and the Pt NPs remain highly ordered arrays with predictable spacing when the Pt concentration is larger than 0.125 mg ml−1. Decrease in Pt concentration from 2 to 0.125 mg ml−1 is an effective method to improve the ECSA and durability simultaneously. The Pt NP arrays exhibit not only a remarkable initial ECSA value of 106.2 m2 g−1, but also a pseudo-zero particle aggregation possibility during 3000-cycle voltammetry, which is attributed to the high Pt NP dispersion and the ordered arrays that improve the Pt utilization and lower the possibility of aggregation.

Hydrogen production from steam reforming of acetic acid was investigated over Ni/La2O3-ZrO2 catalyst. A series of Ni/La2O3-ZrO2 catalysts were synthesized by sol-gel method coupled with wet impregnation, which was characterized by XRD, BET, TEM, EDS, TG, SEM and TPR. Catalytic activity of Ni/La2O3-ZrO2 was evaluated by steam reforming of acetic acid at the temperature range of 550-750 °C. The tetragonal phase La0.1Zr0.9O1.95 is formed through the doping of La2O3 into the ZrO2 lattice and nickel species are highly dispersed on the support with high specific surface area. H2 yield and CO2 yield of Ni/La2O3-ZrO2 catalyst with 15%wt Ni reaches 89.27% and 80.41% at 600 °C, respectively, which is attributed to high BET surface area and sufficient Ni active sites in strong interaction with the support. 15%wt Ni supported on La2O3-ZrO2 catalyst maintains relatively stable catalytic activities for a period of 20 h.

The spatial distribution of the eutectic M B borides in Fe-Cr-B cast irons was predicted using strain models. The spatial distribution of the eutectic M B borides was revealed by scanning electron microscopy (SEM) using deep-etched specimens. It was shown that the models are helpful for the prediction of mechanical properties, as well as interpretation of mechanical property difference of Fe-Cr-B cast irons. The results show that the models are successful in the prediction of the spatial distribution of the eutectic M B borides.