Green rusts with brucite-like layers of hydroxide intercalated with anions constitute a family of diverse precursors for the synthesis of iron oxides via dehydration, but precise structural control of the resulting oxides with respect to the size and shape at the nanometer level remains challenging due to the easy oxidation of the ferrous species. Herein, we report a new synthetic strategy for the facile preparation of fibrous-like green rusts by using appropriate balancing anions (CO32− and SO42−) in ethylene glycol to regulate the morphology. Depending on the type of the intercalating anion, the green rusts were converted into hematite with fibrous- or plate-like shapes upon thermal activation. When evaluated in the reaction of NO reduction by CO, these iron oxides showed a prominent shape-dependent catalytic behavior. The fibrous-like Fe2O3 was much more catalytically active and structurally robust than the plate-like analogue. Combined spectroscopic and microscopic characterizations on the nanostructured iron oxides revealed that the superior performance of the fibrous-like Fe2O3 stemmed from a facile Fe2O3/Fe3O4 redox cycle and a higher density of active sites for NO activation.
Abstract The shape of the carriers has a profound impact on the catalytic performance of metal‐supported catalysts. Herein, ZrO 2 of different shapes (nanorods‐like, spherical or irregular nanoparticles, demoted as RZ, SPZ, and IPZ, respectively) are adopted to disperse Ni species to assess the shape effects on the catalytic performance in dry reforming of methane. To this end, the fresh and spent catalysts are thoroughly characterized by multiple techniques including N 2 sorption, powder X‐ray diffraction, temperature‐programmed reduction with H 2 , thermogravimetric analyses, transmission electron microscopy, Raman and X‐ray photoelectron spectroscopies. It is revealed that the reducibility of NiO species follows the orders of Ni/RZ<Ni/SPZ<Ni/IPZ. Consequently, Ni/RZ and Ni/SPZ show lower dehydrogenation activity than Ni/IPZ, but the more abundant lattice oxygen species promote the gasification of carbonaceous deposits. Therefore, the shape design of the carriers provides a new perspective in mediating the catalytic performance of Ni/ZrO 2 in the reforming reaction.
In the present study, we were to screen the specific microRNA (miRNA) of exercise-induced muscle damage (EIMD) and assess the EIMD-specific miRNAs-regulated target of sarcolemmal damage in rats. Twenty-four male Sprague-Dawley (SD) rats were randomly divided into 3 groups, which included sedentary (C), 24 h post-exercise (E24) and 48 h post-exercise (E48) groups. Rat EIMD model was established by an acute eccentric exercise, i.e., a downhill running treatment at -16º gradient. EIMD characteristics were verified by Evans blue dye staining, differentially expressed miRNAs were detected by microarray assay, EIMD-specific miRNAs expressions were further validated by real-time quantitative RT-PCR (RT-qPCR), and targets of the miRNAs were predicted based on mRNA expressions of associated proteins and related pathway core molecules of sarcolemmal damage. Two EIMD-specific expressed miRNAs, including miR-206-3p and miR-139-3p, were found in the study. There was a significantly negative correlation (P < 0.05) between miR-206-3p expression and dystrophin (r = -0.68), utrophin (r = -0.64), JNK (r = -0.62) or ERK1 (r = -0.68) respectively, but no correlation was found between miR-139-3p and these biomolecules. The results suggest that: i) the expression profile of miRNAs in rat is significantly affected by EIMD, ii) miR-206-3p and miR-139-3p are the EIMD-specific miRNAs, and iii) miR-206-3p may control sarcolemmal damage by regulating dystrophin, utrophin, JNK and ERK1.
This paper makes a study of the rater reliability in scoring composition in the test of English as a foreign language (EFL) and focuses on the inter-rater reliability as well as several interactions between raters and the other facets involved (that is examinees, rating criteria and rating methods). Results showed that raters were fairly consistent in their overall ratings. This finding has the great implications for controlling and assuring the quality of the rater-mediated assessment system.
The development of modern electronic image technology has enabled us to analyze the artistic composition of Chinese landscaping paintings from a much fresher and broader perspective.The application of electronic image technology can help us to utilize graphic analysis to further understand the compositional features and aesthetic values of Chinese landscape paintings.
p62 is an important multifunctional protein capable of binding ubiquitin-proteasome and autophagy substrates. It is involved in skeletal muscle metabolic adaption to various stresses under insulin resistance (IR) and type 2 diabetes mellitus (T2DM) related metabolic diseases. However, the exact functional role of p62 in regulating glucose metabolism in skeletal muscle remains unclear. Herein, we investigated the effect of p62siRNA in regulating glucose metabolism in C2C12 myotubes under a high-fat environment and its links to AMPK mediated autophagy pathway. PA-induced glucose metabolism disturbance and downregulated AMPK activity and GLUT4 expression, which was associated with increased p62 protein expression. p62siRNA effectively mitigated the impaired AMPK activity and decreased GLUT4 expression, and ameliorated glucose metabolism disturbance. p62siRNA also markedly restored autophagy activity. Our findings support that p62siRNA contributed to restoring the impaired glucose uptake and glucose consumption in high-fat environment through AMPK activation and GLUT4 expression, at least partially dependent on autophagy activation. p62 may be an important therapeutic cellular target in high-fat-induced glucose metabolism disturbance in skeletal muscle under IR-related conditions.
Supported nickel catalysts represent a class of important catalytic materials in selective hydrogenations, but applications are frequently limited by metal agglomeration or active-site blocking induced by the presence of hydrogen halides. Herein, we report a novel pre-coking strategy, exposing the nickel nanoparticles under methane dry reforming conditions to manipulate performance in the continuous-flow hydrogenation of 1,2-dichloro-4-nitrobenzene. Compared with the pristine nickel catalyst, the nanotube-like coke-modified nickel catalyst showed weakened hydrogenating ability, but much improved stability and slightly better selectivity to the target product, 3,4-dichloroaniline. Characterization results revealed that the strengthened stability performance can be mainly linked to the reduced propensity to retain chlorine species, which seems to block the access of the substrate molecules to the active sites, and thus is a major cause of catalyst deactivation on the pristine nickel catalyst. Coke deposition can occur on the pre-coked nickel catalyst but not on the pristine analog; however, the impact on the stability performance is much milder compared with that on chlorine uptake. In addition, the presence of coke is also beneficial in restraining the growth of the nickel nanoparticles. Generally, the developed method might provide an alternative perspective on the design of novel transition-metal-based catalytic materials for other hydrogenation applications under harsh conditions.
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