5‐Hydroxymethylfurfural (HMF) containing C=O, C−O, and furan ring functional groups is an important platform chemical derived from C6 sugars. The selective hydrogenation of C=O in HMF produces ...2,5‐dihydroxymethylfuran (DHMF), which is a potential sustainable substitute for petroleum‐based building blocks. Here, 2,5‐furandicarboxylic acid (H2FDC), a promising sustainable alternative to terephthalic acid, was employed as a renewable ligand to synthesize a novel Cu metal‐organic framework (Cu‐FDC). With a polyvinyl pyrrolidone (PVP)‐assisted approach, 2D Cu‐FDC nano‐lamellae of micrometer lateral dimensions and nanometer thickness could be obtained, which could be used as a precursor to fabricate 2D oxygen‐rich carbon nanosheets embedded with Cu nanoparticles (denoted CFP‐300) after a thermal treatment at 300 °C under N2 atmosphere. The synthesized CFP‐300 exhibited excellent catalytic performance and stability for the selective hydrogenation of HMF to DHMF. These results demonstrated a sustainable route to synthesize efficient catalysts by employing metal–organic frameworks based on renewable ligands.
Turn up the heat: Cu−NPs@C nanosheets with excellent catalytic activity in the selective hydrogenation of 5‐hydroxymethylfurfural to 2,5‐dihydroxymethylfuran are obtained via a heat treatment of a polyvinyl pyrrolidone‐assisted 2D Cu meta–organic framework based on a renewable ligand under N2 atmosphere.
Transition metal disulfides have shown promising catalytic activity, while carbides possess high stability toward water electrocatalysis. It is an ideal way to develop high-performance ...electrocatalysts with enhanced activity and stability by combining the two compounds together. Herein, we present a new strategy to promote the sulfidation process of Ni nanoparticles by modifying with MoxC, which can increase the ratio of pyrrolic-N and pyridine-N. Interestingly, the increase of pyrrolic-N can further promote the metal Ni completely sulfurized into NiS2 nanoparticles. The as-synthesized material of NiS2 nanoparticles coated with self-grown carbon nanotubes modified by Mo2C can serve as bifunctional electrode, which achieves a current density of 10 mA cm−2 at a voltage of 1.52 V to generate H2 and O2 gases in alkaline media. Moreover, it can maintain 24 h stability at different current densities, which is more stable than N-CNTs/NiS2-Ni without Mo element. This finding provides a new method and idea for the development of new composite electrocatalysts toward more efficient water splitting.
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•MoxC anchored canbon nanotubes can increase the content of pyrrolic-N to enhance the formation of NiS2 nanoparticles.•MoxC anchored canbon nanotubes provide corrosion-resistant space for NiS2, enabling it to catalyze the decomposition of water more stable.•The synergistic effect of NiS2 and Mo2C not only improves the catalytic performance, but also greatly enhances its stability.
The load data in smart grid contains a lot of valuable knowledge, which is useful for both electricity producers and consumers. Load classification is an important issue in load data mining. A ...five-stage process model of load classification is constructed based on the summary and analysis of studies about load classification in smart grid environment. Then, the commonly used clustering methods for load classification are summarized and briefly reviewed, and the well-known evaluation methods for load classification are also introduced. Besides, the applications of load classification, including bad data identification and correction, load forecasting and tariff setting, are discussed. Finally, an example of load classification based on Fuzzy c-means (FCM) is presented.
MicroRNA-221 (miRNA-221) is upregulated in several malignant tumors and is associated with poor patient prognosis. Therefore, the present study aimed to investigate the role and underlying mechanism ...of miRNA-221 in doxorubicin (DOX) resistance in osteosarcoma cells. We constructed DOX-resistant Saos-2/DOX cells and treated them with DOX. Cell viability was determined by performing a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cells were transfected with either miRNA-221 mimic or miRNA-221 inhibitor; quantitative (q)RT-PCR was performed to detect the expression of miRNA-221. Flow cytometry and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-digoxigenin nick-end labeling (TUNEL) staining were used to detect cell apoptosis. The immunofluorescence method was also used to detect cell signal transduction and activator of transcription 3 (Stat3) protein expression distribution. In addition, Western blotting was used to detect changes in the expression of each protein. We found that miRNA-221 was upregulated in Saos-2/DOX cells. Moreover, the miRNA-221 mimic induced DOX resistance in Saos-2 cells, whereas the miRNA-221 inhibitor enhanced DOX sensitivity in Saos-2/DOX cells. The miRNA-221 mimic upregulated the expression of phosphorylated-Stat3, P-glycoprotein (P-gp), and B-cell lymphoma-2 (Bcl-2) proteins in Saos-2 cells and induced the entry of Stat3 into the nucleus, whereas the miRNA-221 inhibitor exerted the opposite effect. Pretreatment with the Stat3 chemical inhibitor, STAT3-IN-3, significantly inhibited the upregulation of P-gp and Bcl-2 protein expression induced by the miRNA-221 mimic in Saos-2 cells; it also caused the Saos-2 cells to overcome DOX resistance induced by the miRNA-221 mimic. Thus, miRNA-221 increased the expression of P-gp and Bcl-2 by activating the Stat3 pathway to promote DOX resistance in osteosarcoma cells, indicating a potential use of miRNA-221 in osteosarcoma treatment.
This study focused on the resource recovery of sludge treatment by quantifying the environmental contributions, identifying the influential factors, and comparing different scenarios. Life cycle ...assessment (LCA) of sewage sludge treatment was carried out to estimate the environmental impacts of six scenarios: (1) co-digestion of sludge and food waste; (2) co-gasification of sludge and woody waste; (3) co-incineration of sludge and used oil; (4) landfilling; (5) incineration; and (6) anaerobic digestion combined with incineration. Results demonstrate that the resource recovery had a substantial contribution to the environmental performance of the sludge treatment, while the degree of contribution was largely affected by various treatment scenarios and diverse impact categories. To gain deep insight into the parameters related to resource recovery, sensitivity analysis was performed to investigate the influence of the parameters on the LCA results, including the organic content, conversion efficiency of organic matter to methane, and other energy conversion efficiencies. After integrating the inventory variation of those parameters into the decision process via the Monte Carlo simulation, results indicate that no obviously superior scenario could be identified. Conversely, when parameter uncertainty was not considered, co-gasification of sludge and woody waste exhibited the most preferable environmental performance. Overall, this study demonstrates that considering the parameter uncertainty of resource recovery will contribute to a more transparent evaluation process, but will inevitably increase the complexity of the decision-making process based on LCA results because it is difficult to determine a sludge treatment scenario that decisively outperforms the others.
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•Life cycle environment impact of six sludge treatment scenarios were evaluated.•Resource recovery had a large impact on the environmental impact of the scenario.•Sensitivity analysis showed significant differences of different parameters.•Considering uncertainty increases the complexity of decision making based on LCA.
Polypropylene (PP), a fossil-based polyolefin plastics widely used worldwide, is non-hydrolyzable and resistant to biodegradation as a major source of plastic pollutants in environment. This study ...focused on feasibility of PP biodegradation in the larvae of two species of darkling beetles (Coleoptera: Tenebrionidae) i.e., yellow mealworms (Tenebrio molitor) and superworms (Zophobas atratus) using PP foam with number-, weight-, and size-average molecular weights (Mn, Mw, and Mz) of 109.8, 356.2, and 765.0 kDa, respectively. The tests were conducted in duplicates with respective larvae (300 T. molitor and 200 Z. atratus each incubator) at 25 °C and 65% humidity for over a 35-day period. The larvae of T. molitor and Z. atratus fed with PP foam as sole diet consumed PP at 1.0 ± 0.4 and 3.1 ± 0.4 mg 100 larvae−1 days−1, respectively; when fed the PP foam plus wheat bran, the consumption rates were enhanced by 68.11% and 39.70%, respectively. Gel permeation chromatography analyses of the frass of T. molitor and Z. atratus larvae fed PP only indicated that Mw was decreased by 20.4 ± 0.8% and 9.0 ± 0.4%; Mn was increased by 12.1 ± 0.4% and 61.5 ± 2.5%; Mz was decreased by 33.8 ± 1.5% and 32.0 ± 1.1%, indicating limited extent depolymerization. Oxidation and biodegradation of PP was confirmed through analysis of the residual PP in frass. Depression of gut microbes with the antibiotic gentamicin inhibited PP depolymerization in both T. molitor and Z. atratus larvae. High throughput 16S rRNA sequencing revealed that Citrobacter sp. and Enterobacter sp. were associated with PP diets in the gut microbiome of Z. atratus larvae while Kluyvera was predominant in the T. molitor larvae. The results indicated that PP can be biodegraded in both T. molitor and Z. atratus larvae via gut microbe-dependent depolymerization with diversified microbiomes.
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•Tenebrio molitor and Zophobas atratus consumed PP foam.•PP was biodegraded via limited extent depolymerization with Mz reduction >32%.•Antibiotic tests indicated gut-microbe dependent biodegradation in both larvae.•Microbiome shifted with distinct dominant species during PP degradation.
Two parallel sequence batch reactors (SBRs) were operated, with and without TCS addition, to research the causes of sludge reduction by uncouplers. Three possible mechanisms of sludge reduction by ...TCS were studied: (1) occurrence of metabolic uncoupling, (2) consumption of more energy to resist the infection of TCS, (3) promotion of lysis-cryptic growth by TCS addition. Results showed the remarkable reduction of electronic transport system (ETS) activity and specific cellular ATP (SATP) in TCS reactor, which proved the occurrence of metabolic uncoupling. The increasing amounts of extracellular polymeric substances (EPS), as measured by chemical methods and excitation-emission matrix (EEM) fluorescence spectra, implied microorganisms consumed more energy to resist TCS. The similar DNA concentrations of the effluents in two reactors indicated sludge lysis was not intensified by TCS. Therefore, uncoupler might not only cause metabolic uncoupling but also induce more energy consumption in the production of some substances to resist uncoupler.
Sulfenylation of C–H bonds for C–S bond formation under metal‐free conditions has become established as a powerful tool in organic chemistry. Various sulfenylation reagents such as thiols, ...disulfides, sulfinic acids, and so on have been employed for sulfenynlation reactions. In this review we mainly summarize the recent advances (2014 to the present) in this area and also discuss the mechanisms.
Sulfenylation of C–H bonds has recently come to receive more and more attention. In this Microreview, recent advances in sulfenylation of C–H bonds for C–S bond formation under metal‐free conditions are reviewed.
Commercial production of polystyrene (PS) -a persistent plastic that is not biodegradable at appreciable rates in most environments-has led to its accumulation as a major contaminant of land, rivers, ...lakes, and oceans. Recently, however, an environment was identified in which PS is susceptible to rapid biodegradation: the larval gut of Tenebrio molitor Linnaeus (yellow mealworms). In this study, we evaluate PS degradation capabilities of a previously untested strain of T. molitor and assess its survival and PS biodegradation rates for a range of conditions (two simulated food wastes, three temperatures, seven PS waste types). For larvae fed PS alone, the %PS removed in the short (12–15 h) residence time of the mealworm gut gradually increased for 2–3 weeks then stabilized at values up to 65%. Thirty two-day survival rates were >85% versus 54% for unfed larvae. For mealworms fed ∼10% w/w PS and ∼90% bran, an agricultural byproduct, rates of PS degradation at 25 °C nearly doubled compared to mealworms fed PS alone. Polymer residues in the frass showed evidence of partial depolymerization and oxidation. All of the tested PS wastes degraded, with the less dense foams degrading most rapidly. Mealworms fed bran and PS completed all life cycle stages (larvae, pupae, beetles, egg), and the second generation had favorable PS degradation, opening the door for selective breeding.
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•Polystyrene (PS) biodegrades in a mealworm strain from a U.S. source.•Supplemental nutrition increases PS biodegradation rates.•Optimal PS removal occurs at 25 °C using a bran feed that has 6–11% (w/w) PS.•All PS foams degrade, with low density foams degrading most rapidly.•A 2nd generation of mealworms fed bran and PS has high rates of PS biodegradation.
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