Hard carbon attracts considerable attention as an anode material for sodium‐ion batteries; however, their poor rate capability and low realistic capacity have motivated intense research effort toward ...exploiting nanostructured carbons in order to boost their comprehensive performance. Ultramicropores are considered essential for attaining high‐rate capacity as well as initial Coulombic efficiency by allowing the rapid diffusion of Na+ and inhibiting the contact of the electrolyte with the inner carbon surfaces. Herein, hard carbon nanosheets with centralized ultramicropores (≈0.5 nm) and easily accessible carbonyl groups (CO)/hydroxy groups (OH) are synthesized via interfacial assembly and carbonization strategies, delivering a large capacity (318 mA h g−1 at 0.02 A g−1), superior rate capability (145 mA h g−1 at 5.00 A g−1), and approximately 95% of reversible capacity below 1.00 V. Notably, a new charge model favoring fast capacitive sodium storage with dual potential plateaus is proposed. That is, the deintercalation of Na+ from graphitic layers is manifested as the low‐potential plateau region (0.01−0.10 V), contributing to stable insertion capacity; meanwhile, the surface desodiation process of the CO and OH groups corresponds to the high‐potential plateau region (0.40−0.70 V), contributing to a fast capacitive storage.
Hard carbon nanosheets with centralized ultramicropores (≈0.5 nm), accessible functional CO/OH groups, and large graphitic layer spacings exhibit excellent sodium‐storage properties. The desodiation process from graphitic layers and CO/OH groups results in a new sodium‐storage characteristic with dual‐potential plateaus during the charge process, which favors a high output of 95%, realistic capacity, and rapidly capacitive sodium storage.
NiOOH is one of the most promising catalysts for electrooxidation of water and organic molecules. Accompanying the long experimental practice to optimize the catalyst, atomic simulations, mainly ...based on density functional theory (DFT) calculations, have been performed in recent years to reveal the atomic structure of NiOOH and the reaction mechanism in catalysis. Due to both the structural complexity and the difficulty in computing the electronic structure, there are great concerns over the accuracy of first-principles methods and the validity of the structure models. This Perspective serves to overview the current status of atomic simulation on the structure and catalysis of NiOOH. We first present NiOOH phases and structures obtained by the latest global optimization methods in combination with machine learning potentials. The electronic structures of NiOOH are then described by comparing the performance of different theoretical levels, in particular, those based on PBE+U and hybrid functionals in DFT calculations. Finally, taking the oxygen evolution reaction of water splitting as the example, we elaborate the catalytic mechanism on pure, defective, and Fe-doped NiOOH surfaces and provide insights into the exceptional activity of the doped system. The further directions for theoretical investigations on NiOOH are also discussed.
This paper reviews the current understanding of the molecular basis of the peroxisome proliferator‐activated receptor‐γ coactivator‐1α (PGC‐1α)–mediated pathway and discusses the role of PGC‐1α in ...skeletal muscle atrophy caused by immobilization. PGC‐1α is the master transcription regulator that stimulates mitochondrial biogenesis, by upregulating nuclear respiratory factors (NRF‐1, 2) and mitochondrial transcription factor A (Tfam), which leads to increased mitochondrial DNA replication and gene transcription. PGC‐1α also regulates cellular oxidant–antioxidant homeostasis by stimulating the gene expression of superoxide dismutase‐2 (SOD2), catalase, glutathione peroxidase 1 (GPx1), and uncoupling protein (UCP). Recent reports from muscle‐specific PGC‐1α overexpression underline the importance of PGC‐1α in atrophied skeletal muscle, demonstrate enhancement of the PGC‐1α mitochondrial biogenic pathway, and reduced oxidative damage. Thus, PGC‐1α appears to play a protective role against atrophy‐linked skeletal muscle deterioration.
The electrochemical performance of most transition metal oxides based on the conversion mechanism is greatly restricted by inferior cycling stability, rate capability, high overpotential induced by ...the serious irreversible reactions, low electrical conductivity, and poor ion diffusivity. To mitigate these problems, highly porous Mn3O4 micro/nanocuboids with in situ formed carbon matrix (denoted as Mn3O4@C micro/nanocuboids) are designed and synthesized via a one‐pot hydrothermal method, in which glucose plays the roles of a reductive agent and a carbon source simultaneously. The carbon content, particle size, and pore structure in the composite can be facilely controlled, resulting in continuous carbon matrix with abundant pores in the cuboids. The as‐fabricated Mn3O4@C micro/nanocuboids exhibit large reversible specific capacity (879 mAh g−1 at the current density of 100 mA g−1) as well as outstanding cycling stability (86% capacity retention after 500 cycles) and rate capability, making it a potential candidate as anode material for lithium‐ion batteries. Moreover, this facile and effective synthetic strategy can be further explored as a universal approach for the synthesis of other hierarchical transition metal oxides and carbon hybrids with subtle structure engineering.
A facile one‐pot synthetic route is rationally designed and employed for the synthesis of porous Mn3O4 micro/nanocuboids with in situ coated carbon. The smart electrode design realizes efficient transportation of electrons and ions. By tuning the size and porosity of Mn3O4@C micro/nanocuboids, an outstanding cycling stability with a large reversible specific capacity and excellent rate capability are achieved.
The increasing importance of lignocellulosic biomass as a renewable energy source has led to an acute need for reliable and detailed information on its assessment, consumption and supply. With the ...passage of China’s legislative targets for renewable portfolio standards, agricultural residue resources have the potential for an increasing role in meeting liquid fuels demand in China. An assessment of current and near future agricultural residue resources (including agricultural crop residues and secondary agricultural processing residues) in China at national scale was conducted. This paper gave the theoretical quantity, collectable quantity, usable quantity and potential quantity for liquid biofuel production of agricultural residues in China. The spatial and seasonal distributions of crop residues were analyzed. The theoretical output of crop residues in China at national scale in the near future were forecasted by means of an artificial neural network (ANN) model. The availability of agricultural residues in China was presented, as a result, the potential of liquid biofuels from agricultural residues was discussed. The ANN predicted results have shown that the theoretical output of crop residues in China at national scale will be up to 930.8 million tons in 2015. About 44 million tons per year of bioethanol or 131 million tons per year of bio-oil would have been produced, if the total usable output of agricultural crop residues were used to produce bioethanol through biochemical conversion process or bio-oil through fast pyrolysis, which could replace 26.9 million tons of gasoline or 58.2 million tons of diesel at national scale in 2015, respectively. The above results will be helpful for commercialization of bioenergy industry and their market-oriented development strategy, so as to accelerate the development of industrialization of biofuel technologies.
Microcystins (MCs) are common cyanotoxins produced by harmful cyanobacterial blooms (HCBs) and severely threaten human and ecosystems health. Biodegradation is an efficient and sustainable biological ...strategy for MCs removal. Many novel findings in fundamental knowledge and application potential of MC-biodegradation have been documented. Little effort has devoted to summarize and comment recent research progress on MC-biodegradation, and discuss the research problems and gaps. This review deals with current research scenario in aerobic and anaerobic biodegradation for MCs. Diverse organisms capable of degrading MCs are encapsulated. Enzymatic mechanisms and influence factors regulating aerobic and anaerobic MC-biodegradation are summarized and discussed, which are essential for assessing and reducing MC-risks during HCBs episodes. Also, we propose some ideas to solve the challenges and bottleneck problems in practical application of MC-biodegradation, and discuss research gaps and promising research methods which deserve special attention. This review may provide new insights on future direction of MC-biodegradation research, in order to further broaden its application prospects for bioremediation.
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•The review recounts current research advances for microcystins biodegradation.•Microcystins degradation by diverse organisms and involved mechanisms are reviewed.•Microcystins biodegradation efficacies affected by multiple factors are summarized.•The ideas to solve bottleneck problems in application of biodegradation are discussed.•Data gaps and future direction in microcystins biodegradation research are proposed.
Pistachio (Pistacia vera), one of the most important commercial nut crops worldwide, is highly adaptable to abiotic stresses and is tolerant to drought and salt stresses.
Here, we provide a draft de ...novo genome of pistachio as well as large-scale genome resequencing. Comparative genomic analyses reveal stress adaptation of pistachio is likely attributable to the expanded cytochrome P450 and chitinase gene families. Particularly, a comparative transcriptomic analysis shows that the jasmonic acid (JA) biosynthetic pathway plays an important role in salt tolerance in pistachio. Moreover, we resequence 93 cultivars and 14 wild P. vera genomes and 35 closely related wild Pistacia genomes, to provide insights into population structure, genetic diversity, and domestication. We find that frequent genetic admixture occurred among the different wild Pistacia species. Comparative population genomic analyses reveal that pistachio was domesticated about 8000 years ago and suggest that key genes for domestication related to tree and seed size experienced artificial selection.
Our study provides insight into genetic underpinning of local adaptation and domestication of pistachio. The Pistacia genome sequences should facilitate future studies to understand the genetic basis of agronomically and environmentally related traits of desert crops.
Toosendanin (TSN) is the main active compound in Toosendan Fructus and Meliae Cortex, two commonly used traditional Chinese medicines. TSN has been reported to induce hepatotoxicity, but its ...mechanism remains unclear. In this study, we demonstrated the critical role of nuclear factor erythroid 2-related factor 2 (Nrf2) in protecting against TSN-induced hepatotoxicity in mice and human normal liver L-02 cells. In mice, administration of TSN (10 mg/kg)-induced acute liver injury evidenced by increased serum alanine/aspartate aminotransferase (ALT/AST) and alkaline phosphatase (ALP) activities, and total bilirubin (TBiL) content as well as the histological changes. Furthermore, TSN markedly increased liver reactive oxygen species (ROS) and malondialdehyde (MDA) levels, and decreased liver glutathione (GSH) content and Nrf2 expression. In L-02 cells, TSN (2 μM) time-dependently reduced glutamate-cysteine ligase (GCL) activity and cellular expression of the catalytic/modify subunit of GCL (GCLC/GCLM). Moreover, TSN reduced cellular GSH content and the increased ROS formation, and time-dependently decreased Nrf2 expression and increased the expression of the Nrf2 inhibitor protein kelch-like ECH-associated protein-1 (Keap1). Pre-administration of quercetin (40, 80 mg/kg) effectively inhibited TSN-induced liver oxidative injury and reversed the decreased expression of Nrf2 and GCLC/GCLM in vivo and in vitro. In addition, the quercetin-provided protection against TSN-induced hepatotoxicity was diminished in Nrf2 knock-out mice. In conclusion, TSN decreases cellular GSH content by reducing Nrf2-mediated GCLC/GCLM expression via decreasing Nrf2 expression. Quercetin attenuates TSN-induced hepatotoxicity by inducing the Nrf2/GCL/GSH antioxidant signaling pathway. This study implies that inducing Nrf2 activation may be an effective strategy to prevent TSN-induced hepatotoxicity.
Electrochemical water splitting is one of the most economical and sustainable methods for large-scale hydrogen production. However, the development of low-cost and earth-abundant non-noble-metal ...catalysts for the hydrogen evolution reaction remains a challenge. Here we report a two-dimensional coupled hybrid of molybdenum carbide and reduced graphene oxide with a ternary polyoxometalate-polypyrrole/reduced graphene oxide nanocomposite as a precursor. The hybrid exhibits outstanding electrocatalytic activity for the hydrogen evolution reaction and excellent stability in acidic media, which is, to the best of our knowledge, the best among these reported non-noble-metal catalysts. Theoretical calculations on the basis of density functional theory reveal that the active sites for hydrogen evolution stem from the pyridinic nitrogens, as well as the carbon atoms, in the graphene. In a proof-of-concept trial, an electrocatalyst for hydrogen evolution is fabricated, which may open new avenues for the design of nanomaterials utilizing POMs/conducting polymer/reduced-graphene oxide nanocomposites.
Contraction-induced production of reactive oxygen species has been shown to cause oxidative stress to skeletal muscle. As an adaptive response, muscle antioxidant defense systems are upregulated in ...response to exercise. Nuclear factor κB and mitogen-activated protein kinase are two major oxidative-stress-sensitive signal transduction pathways that have been shown to activate the gene expression of a number of enzymes and proteins that play important roles in maintenance of intracellular oxidant–antioxidant homeostasis. This mini-review will discuss the main mechanisms and gene targets for these signaling pathways during exercise and the biological significance of the adaptation.
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