The practical application of the Zn‐metal anode for aqueous batteries is greatly restricted by catastrophic dendrite growth, intricate hydrogen evolution, and parasitic surface passivation. Herein, a ...polyanionic hydrogel film is introduced as a protective layer on the Zn anode with the assistance of a silane coupling agent (denoted as Zn–SHn). The hydrogel framework with zincophilic –SO3− functional groups uniformizes the zinc ions flux and transport. Furthermore, such a hydrogel layer chemically bonded on the Zn surface possesses an anti‐catalysis effect, which effectively suppresses both the hydrogen evolution reaction and formation of Zn dendrites. As a result, stable and reversible Zn stripping/plating at various currents and capacities is achieved. A full cell by pairing the Zn–SHn anode with a NaV3O8·1.5 H2O cathode shows a capacity of around 176 mAh g−1 with a retention around 67% over 4000 cycles at 10 A g−1. This polyanionic hydrogel film protection strategy paves a new way for future Zn‐anode design and safe aqueous batteries construction.
A unique polyanionic hydrogel is employed as an artificial protective layer for reversible Zn‐metal anodes. The polyanions in the hydrogel framework facilitate a homogeneous zinc‐ion flux, and the Zn–O bonding strengthens the interface and suppresses surface corrosion and irregular Zn dendrites growth. This strategy could apply also to other aqueous metal batteries.
The correlation between metal coordination and electrocatalytic water oxidation performance is elusive in many cobalt‐based materials. Herein, we designed an ideal Co phosphate‐based platform to ...explore the effect of coordination environment on oxygen evolution reaction (OER) activity. The cobalt geometry was modulated from octahedral to tetrahedral by simple removal of water ligands in Co3(PO4)2⋅8 H2O. Other features except the coordination structure in the two autologous materials remain similar. The two analogues display the same OER kinetics, but the anhydrous Co3(PO4)2 exhibits a greatly enhanced OER activity. On the basis of Raman and operando XAS results, the higher intrinsic activity of the Co tetrahedral sites is because they facilitate the formation of active high valent cobalt (hydr)oxide intermediates during OER. This work not only brings insights of OER on Co‐based electrocatalysts but also provides a reference system to study the effect of metal geometry on electrocatalysis.
Origins of OER: The metal geometry in cobalt phosphates was modulated from octahedral to tetrahedral by the simple removal of crystal water in Co3(PO4)2⋅8 H2O. The two materials form an ideal platform for the study the oxygen evolution reaction (OER) related to the metal coordination structure.
The large‐scale deployment of aqueous Zn‐ion batteries is hindered by Zn anode instability including surface corrosion, hydrogen gas evolution, and irregular Zn deposition. To tackle these ...challenges, a polyhydroxylated organic molecular additive, trehalose, is incorporated to refine the solvation structure and promote planar Zn deposition. Within solvation structure regions involving trehalose, the hydroxy groups participate in the reconstruction of hydrogen bond networks, which increases the overpotential for water decomposition reaction. Moreover, at the Zn metal–molecule interface, the chemisorption of trehalose onto the surface of the zinc anode enhances corrosion resistance and facilitates the deposition of zinc in a planar manner. The optimized electrolyte significantly improves Zn striping/plating reversibility and maintains stable potentials over 1600 h at 5 mA cm−2 with a cutoff capacity of 1 mA h cm−2 in symmetric cells. When combined with the MnO2 cathode, the assembled coin cell retains ≈89% of its capacity after 1000 cycles. This organic molecule additive, emphasizing the role of polyhydroxylated organic molecules in fine‐tuning solvation structures and anode/electrolyte interfaces, holds promise for enhancing various aqueous metal batteries.
Trehalose, a widely used moisturizer, preservative, and stabilizer in the food industry, is proven to be an effective electrolyte additive to the sulfite electrolyte for aqueous zinc ion battery. It optimizes the solvation structure by decreasing free water molecules and forming hydrogen bond networks. Trehalose also stabilizes the metal‐electrolyte interface through chemisorption, benefiting planar zinc deposition and suppressing dendrite growth.
Douchi is a type of Chinese traditional fermented food that is an important source of protein and is used in flavouring ingredients. The end product is affected by the microbial community present ...during fermentation, but exactly how microbes influence the fermentation process remains poorly understood. We used an Illumina MiSeq approach to investigate bacterial and fungal community diversity during both douchi-koji making and fermentation. A total of 181,443 high quality bacterial 16S rRNA sequences and 221,059 high quality fungal internal transcribed spacer reads were used for taxonomic classification, revealing eight bacterial and three fungal phyla. Firmicutes, Actinobacteria and Proteobacteria were the dominant bacterial phyla, while Ascomycota and Zygomycota were the dominant fungal phyla. At the genus level, Staphylococcus and Weissella were the dominant bacteria, while Aspergillus and Lichtheimia were the dominant fungi. Principal coordinate analysis showed structural separation between the composition of bacteria in koji making and fermentation. However, multivariate analysis of variance based on unweighted UniFrac distances did identify distinct differences (p <0.05), and redundancy analysis identified two key genera that are largely responsible for the differences in bacterial composition between the two steps. Staphylococcus was enriched in koji making, while Corynebacterium was enriched in fermentation. This is the first investigation to integrate douchi fermentation and koji making and fermentation processes through this technological approach. The results provide insight into the microbiome of the douchi fermentation process, and reveal a structural separation that may be stratified by the environment during the production of this traditional fermented food.
Research summary: This study examines whether the stock and bond prices of firms engaging in corporate social responsibility (CSR) can benefit from insurance-like effects during occurrences of ...negative events. Our results suggest that in the face of negative events, engagement in CSR on a continuous, long-term basis provides insurance-like effects on both the stock and bond prices of firms. Nevertheless, the effects are found to quickly disappear following the occurrence of a second, or subsequent, negative event. Although our results clearly indicate that firms need to allocate some of their available resources to long-term strategic CSR activities, managers must also realize that in a crisis communication, they will probably be able to use their CSR claims on one occasion only. Managerial summary: The purpose of this article is to examine whether firms engaging in corporate social responsibility (CSR) can benefit from insurance-like effects during occurrences of negative events. We find that on the occurrence of a negative event, long-term CSR engagement does have insurance-like effects. We also find that these insurance-like effects may quickly disappear following the occurrence of a second negative event. Managers of firms with a long history of CSR activities need to realize that in a crisis communication, they can probably use their claims of adherence to CSR only once.
Abstract
Motivation
Linkage disequilibrium (LD) decay is of great interest in population genetic studies. However, no tool is available now to do LD decay analysis from variant call format (VCF) ...files directly. In addition, generation of pair-wise LD measurements for whole genome SNPs usually resulting in large storage wasting files.
Results
We developed PopLDdecay, an open source software, for LD decay analysis from VCF files. It is fast and is able to handle large number of variants from sequencing data. It is also storage saving by avoiding exporting pair-wise results of LD measurements. Subgroup analyses are also supported.
Availability and implementation
PopLDdecay is freely available at https://github.com/BGI-shenzhen/PopLDdecay.
Imbalanced regulation of reactive oxygen species (ROS) and antioxidant factors in cells is known as "oxidative stress (OS)". OS regulates key cellular physiological responses through signal ...transduction, transcription factors and noncoding RNAs (ncRNAs). Increasing evidence indicates that continued OS can cause chronic inflammation, which in turn contributes to cardiovascular and neurological diseases and cancer development. MicroRNAs (miRNAs) are small ncRNAs that produce functional 18-25-nucleotide RNA molecules that play critical roles in the regulation of target gene expression by binding to complementary regions of the mRNA and regulating mRNA degradation or inhibiting translation. Furthermore, miRNAs function as either tumor suppressors or oncogenes in cancer. Dysregulated miRNAs reportedly modulate cancer hallmarks such as metastasis, angiogenesis, apoptosis and tumor growth. Notably, miRNAs are involved in ROS production or ROS-mediated function. Accordingly, investigating the interaction between ROS and miRNAs has become an important endeavor that is expected to aid in the development of effective treatment/prevention strategies for cancer. This review provides a summary of the essential properties and functional roles of known miRNAs associated with OS in cancers.
Terpenes are the largest class of small‐molecule natural products on earth, and the most abundant by mass. Here, we summarize recent developments in elucidating the structure and function of the ...proteins involved in their biosynthesis. There are six main building blocks or modules (α, β, γ, δ, ε, and ζ) that make up the structures of these enzymes: the αα and αδ head‐to‐tail trans‐prenyl transferases that produce trans‐isoprenoid diphosphates from C5 precursors; the ε head‐to‐head prenyl transferases that convert these diphosphates into the tri‐ and tetraterpene precursors of sterols, hopanoids, and carotenoids; the βγ di‐ and triterpene synthases; the ζ head‐to‐tail cis‐prenyl transferases that produce the cis‐isoprenoid diphosphates involved in bacterial cell wall biosynthesis; and finally the α, αβ, and αβγ terpene synthases that produce plant terpenes, with many of these modular enzymes having originated from ancestral α and β domain proteins. We also review progress in determining the structure and function of the two 4Fe‐4S reductases involved in formation of the C5 diphosphates in many bacteria, where again, highly modular structures are found.
Natural building blocks: Recent progress has been achieved in determining the structure, function, and inhibition of the enzymes responsible for the formation of terpenes and isoprenoids. Most of these enzymes contain combinations of α‐, β‐, γ‐, δ‐, ε‐, and/or ζ‐domain structures that in many cases are fused to form modular proteins. Gene fusion, exon loss, and recombination are thought to play major roles in the genesis of these enzymes.
We propose a two-sample testing procedure for high-dimensional time series. To obtain the asymptotic distribution of our ℓ∞-type test statistic under the null hypothesis, we establish ...high-dimensional central limit theorems (HCLTs) for an α-mixing sequence. Specifically, we derive two HCLTs for the maximum of a sum of high-dimensional α-mixing random vectors under the assumptions of bounded finite moments and exponential tails, respectively. The proposed HCLT for α-mixing sequence under bounded finite moments assumption is novel, and in comparison with existing results, we improve the convergence rate of the HCLT under the exponential tails assumption. To compute the critical value, we employ the blockwise bootstrap method. Importantly, our approach does not require the independence of the two samples, making it applicable for detecting change points in high-dimensional time series. Numerical results emphasize the effectiveness and advantages of our method.
Eco-efficiency has been receiving increasing attention across the world. This paper proposes an extended data envelopment analysis model, which combines global benchmark technology, directional ...distance function and a bootstrapping approach to investigate the dynamic trends of regional eco-efficiency in China from 2003 to 2014. Moreover, a developed slacks-based measure is utilized to decompose the performance fluctuations into resource, environmental and economic efficiency. Then, the key factors responsible for the changes in eco-efficiency are explored using the global Malmquist–Luenberger index. The empirical results demonstrate an upward trend of eco-efficiency in China. During the study period this trend was high in eastern and northern areas but low in northwestern areas. However, it should be noted that some eco-efficient regions still consume much land, water and energy and emit much environmental pollutants in absolute terms. The whole of China performs well on the economic front, while resource and environmental performances are not encouraging, particularly on environmental efficiency. The eastern and northern regions have experienced the greatest advances in both resource and environmental efficiency, while the undeveloped areas have not shown much progress, which further widens the gaps between developed areas and undeveloped areas. The decomposition of productivity growth indicates that technical progress is the decisive factor in promoting China's eco-efficiency, while decreasing management level is the major obstacle hampering the improvement in eco-efficiency.
•A bootstrapping approach in global DEA is applied to eco-efficiency assessment.•Eco-efficiency improved gradually during the period of study.•East area experienced the greatest advancement, while the undeveloped areas failed.•Resource and environmental performances are not encouraging in China.•Technical progress is the most powerful contributor to productivity growth.
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