Developing high‐efficiency and cost‐effective alloy catalysts toward hydrogen‐evolution reaction (HER) is crucial for large‐scale hydrogen production via electrochemical water splitting, but ...conventional single‐principal‐element alloy design usually causes insufficient activity and durability of state‐of‐the‐art multimetallic catalysts based on non‐precious transition metals. Herein, we report multicomponent intermetallic Mo(NiFeCo)4 nanoparticles seamlessly integrated on hierarchical nickel network (Mo(NiFeCo)4/Ni) as robust hydrogen‐evolution electrocatalysts with remarkably improved activity and durability by making use of iron and cobalt atoms partially substituting nickel sites to form high‐entropy NiFeCo sublattice in intermetallic MoNi4 matrix, which serve as bifunctional electroactive sites for both water dissociation and adsorption/combination of hydrogen intermediate and improves thermodynamic stability. By virtue of bicontinuous nanoporous nickel skeleton facilitating electron/ion transportation, self‐supported nanoporous Mo(NiFeCo)4/Ni electrode exhibits exceptional HER electrocatalysis, with low Tafel slope (≈35 mV dec−1), high current density (≈2300 mA cm−2) at low overpotential (200 mV) and long‐term durability in 1 m KOH. When coupled to its electrooxidized and nitrified derivative for oxygen‐evolution reaction, their alkaline water electrolyzers operate with a superior overall water‐splitting output, outperforming the one constructed with commercially available noble‐metal‐based catalysts. These electrochemical properties make it an attractive candidate as electrocatalyst in alkaline water electrolysis for large‐scale hydrogen generation.
Multicomponent intermetallic Mo(NiFeCo)4 nanoparticles that are seamlessly integrated on hierarchical nanoporous nickel network (Mo(NiFeCo)4/Ni) hold great promise as low‐cost verstile electrocatalysts for highly efficient water splitting. Associated with hierarchical nanoporous architecture to facilitate electron transfer and offer abundant multicomponent intermetallic active sites, the self‐supported nanoporous Mo(NiFeCo)4/Ni electrode and its electrooxidized/nitrified derivative exhibit remarkably enhanced hydrogen‐evolution and oxygen‐evolution activities and durability.
Metallic zinc is a promising anode material for rechargeable aqueous multivalent metal‐ion batteries due to its high capacity and low cost. However, the practical use is always beset by severe ...dendrite growth and parasitic side reactions occurring at anode/electrolyte interface. Here we demonstrate dynamic molecular interphases caused by trace dual electrolyte additives of D‐mannose and sodium lignosulfonate for ultralong‐lifespan and dendrite‐free zinc anode. Triggered by plating and stripping electric fields, the D‐mannose and lignosulfonate species are alternately and reversibly (de‐)adsorbed on Zn metal, respectively, to accelerate Zn2+ transportation for uniform Zn nucleation and deposition and inhibit side reactions for high Coulombic efficiency. As a result, Zn anode in such dual‐additive electrolyte exhibits highly reversible and dendrite‐free Zn stripping/plating behaviors for >6400 hours at 1 mA cm−2, which enables long‐term cycling stability of Zn||ZnxMnO2 full cell for more than 2000 cycles.
Hybrid aqueous electrolyte of ZnSO4 with trace dual electrolyte additives of D‐mannose and sodium lignosulfonate enables ultralong‐lifespan and dendrite‐free Zn metal anode by virtue of D‐mannose and lignosulfonate species alternately and reversibly adsorb on Zn surface to form dynamical molecular interphases and enter Zn2+ solvation sheath to boost de‐solvation kinetics. Zn anode in such dual‐additive electrolyte exhibits exceptional stability for >6400 hours.
Aqueous zinc‐ion batteries are attractive post‐lithium battery technologies for grid‐scale energy storage because of their inherent safety, low cost and high theoretical capacity. However, their ...practical implementation in wide‐temperature surroundings persistently confronts irregular zinc electrodeposits and parasitic side reactions on metal anode, which leads to poor rechargeability, low Coulombic efficiency and short lifespan. Here, this work reports lamellar nanoporous Cu/Al2Cu heterostructure electrode as a promising anode host material to regulate high‐efficiency and dendrite‐free zinc electrodeposition and stripping for wide‐temperatures aqueous zinc‐ion batteries. In this unique electrode, the interconnective Cu/Al2Cu heterostructure ligaments not only facilitate fast electron transfer but work as highly zincophilic sites for zinc nucleation and deposition by virtue of local galvanic couples while the interpenetrative lamellar channels serving as mass transport pathways. As a result, it exhibits exceptional zinc plating/stripping behaviors in aqueous hybrid electrolyte of diethylene glycol dimethyl ether and zinc trifluoromethanesulfonate at wide temperatures ranging from 25 to −30 °C, with ultralow voltage polarizations at various current densities and ultralong lifespan of >4000 h. The outstanding electrochemical properties enlist full cell of zinc‐ion batteries constructed with nanoporous Cu/Al2Cu and ZnxV2O5/C to maintain high capacity and excellent stability for >5000 cycles at 25 and −30 °C.
Lamellar nanoporous Cu/Al2Cu heterostructure electrodes with high electron/ion transportability and abundant zincophilic sites are constructed as high‐performance anode host materials for wide‐temperature aqueous zinc ion batteries. Benefiting from the unique metal/intermetallic compound heterostructure to form local galvanic couples to facilitate Zn nucleation and deposition, nanoporous Cu/Al2Cu electrode exhibits ultralong‐lifespan stability at 25 and −30 °C.
Cancer stem cells (CSCs), also known as tumor-initiating cells, are a subpopulation of tumor cells that exhibit properties similar to those of normal stem cells. Oxygen is an important regulator of ...cellular metabolism; hypoxia-inducible factors (HIFs) mediate metabolic switches in cells in hypoxic environments. Hypoxia clearly has the potential to exert a significant effect on the maintenance and evolution of CSCs. Both HIF‑1α and HIF‑2α may contribute to the regulation of cellular adaptation to hypoxia and resistance to cancer therapies. This review provides an overview of the roles of HIFs in CSCs. HIF‑1α and HIF‑2α have significant prognostic and predictive value in the clinic and the concept of personalized medicine should be applied in designing clinical trials for HIF inhibitors.
By using the magnetic field data from Van Allen Probes, we analyzed the distribution characteristics of the electromagnetic environment in the inner magnetosphere on different Dst* index and magnetic ...local time. Our results show that for the response of different current systems, the dawn‐dusk and noon‐midnight asymmetry distribution of the residual magnetic field δB increases with Dst* index. When Dst* < −60 nT, a “banana”‐shaped geomagnetic field negative disturbance peak region appears in the sector from midnight to dusk. Then, we obtained the azimuthal current density and found the asymmetric internal eastward and external westward ring current. Through the vector analysis of three‐dimensional current density, the current density vector distribution in the magnetic equatorial plane is completely displayed for the first time, which directly proves the existence of banana current near r = 3.0–4.0 RE during strong geomagnetic storms.
Plain Language Summary
By using the magnetic field data from Van Allen Probes, we find that the electromagnetic environment of the Earth's inner magnetosphere exhibits different distributions on different geomagnetic disturbance strengths. During the occurrence of strong magnetic disturbances, the residual magnetic field δB will exhibit distinct dawn‐dusk and noon‐midnight asymmetric distributions. And a “banana”‐shaped peak region of negative geomagnetic field perturbation will appear in the midnight to dusk sector, while both the eastward and westward ring currents exhibit asymmetry. The presence of the banana current near r = 3.0–4.0 RE during strong geomagnetic storms is then directly demonstrated by vector analysis of the 3D current density.
Key Points
The negative perturbation response of space currents to the geomagnetic field in the inner magnetosphere is analyzed
Both the eastward ring current and westward ring current is asymmetric
The vector distribution diagram of banana current density is obtained
Joint radar and communication (JRC) system is expected to significantly improve the utilization of spectrum resources, system performance, and reduce the equipment cost and size. In this letter, a ...JRC system containing a collocated multi-input multi-output (MIMO) radar and a multi-user communication base station is considered, which can serve several downlink users and detect multiple targets simultaneously. The radar signal covariance matrix and the communication physical precoder are jointly designed by matching the desired beampattern for radar detection while maximizing the downlink communication signal to interference and noise ratio (SINR). By relaxing the original problems, the iterative process with closed-form expressions is proposed to obtain the sub-optimal solutions of the system. Compared with solving the optimization problems directly, the proposed algorithm can significantly reduce the computational complexity with a little loss of system performance. Finally, simulation results show the effectiveness of the proposed algorithm.
Both inter‐ and intraspecific trait variation are critical to species distribution along environmental gradients, but our understanding of these patterns predominantly relies upon species‐level trait ...means and variances. Trait integration, defined as how strongly multiple traits covary with one another, is a key indicator of the dimensionality of functional space for accommodating biodiversity in communities. As trait covariance can differ dramatically at the interspecific versus intraspecific levels, how intraspecific trait variability alters the strength of trait integration and eventually modulates biodiversity along environmental gradients has been rarely tested. Here, we measured nine functional traits (leaf area, specific leaf area, leaf and stem dry‐matter content, leaf nitrogen and phosphorus contents, specific stem length, Huber value and maximum height) paired with site‐specific soil fertility for 70 woody communities in subtropical Chinese forests. All species‐by‐site combinations were sampled to ensure a sufficient representation of intraspecific trait variation across sites. Community‐level trait integration was quantified from the variance of eigenvalues of the trait correlation matrix. The direct and/or indirect effects of soil fertility and trait integration on species richness and trait diversity were assessed through path analyses. Trait integration quantified from both inter‐ and intraspecific variances was on average 21.7% weaker than that from only interspecific variance, indicating a crucial role of intraspecific trait variability in promoting niche dimensionality. Whether accounting for intraspecific variation or not, less fertile sites had stronger trait integration, which in turn depressed both taxonomic and functional diversity, supporting the assumption that higher environmental stress demands stronger tradeoffs among multiple functions in viable strategies. Importantly, the negative association between trait integration and species richness became stronger when accounting for intraspecific variation, suggesting that species distribution and occurrence can be a consequence of intraspecific trait variability. This study highlights the importance of intraspecific trait variability in understanding functional tradeoffs underlying biodiversity patterns.
We examine the economic viability of three multi-effect distillation (MED) based processes against the MED as a benchmark, when they are driven by low grade heat. We model and compare the Boosted MED ...(BMED), Flash Boosted MED (FBMED) and Distributed Boosted MED (DBMED) processes with the MED in terms of waste heat performance ratio, specific capex and opex. All three new configurations generate significantly higher productions than MED with higher capex and opex investment. We provide the corresponding cash-flow analyses using such financial metrics as the Net Present Value (NPV) and Internal Rate of Return (IRR). This study leads to the conclusion that the DBMED process is the superior scenario up to an interest rate of 12.5% at 65 °C heat source supply temperature which then drops to 8.4% at 90 °C heat source supply temperature. Also, the analysis shows for the high interest rates (above 8.4% at 90 °C), MED has higher NPV compared to other MED based processes.
The distributed boosted multi-effect distillation (DBMED) powered with low grade heat resources has been compared against MED, Boosted MED (BMED) and Flash Boosted MED (FBMED) in both technical and economic aspects. Display omitted
•The distributed multi-effect distillation process is the best process for waste heat.•At 65 °C heat source temperature, this process is superior up to 12.5% discount rate.•At 90 °C heat source temperature, this process is superior up to 8.4% discount rate.•Beyond these discount rates, conventional process with lower capex is more viable.
Ubiquitin-conjugating enzyme E2C (UBE2C) has been shown to be associated with the occurrence of various cancers and involved in many tumorigenic processes. This study aimed to investigate the ...specific molecular mechanism through which UBE2C affects breast cancer (BC) proliferation.
BC-related datasets were screened according to filter criteria in the Gene Expression Omnibus (GEO) database and The Cancer Genome Atlas (TCGA) database. Then differentially expressed genes (DEGs) were identified using Venn diagram analysis. By using DEGs, we conducted the following analyses including Gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), protein-protein interaction (PPI), and survival analysis, and then validated the function of the hub gene UBE2C using quantitative reverse transcription-polymerase chain reaction (RT-qPCR), cell counting kit-8 (CCK-8) assay, transwell assay, and Western blot assay.
In total, 151 DEGs were identified from the GEO and TCGA databases. The results of GO analysis demonstrated that the DEGs were significantly enriched with mitotic nuclear division, lipid droplet, and organic acid-binding. KEGG analysis showed that the peroxisome proliferators-activated receptor (PPAR) signaling pathway, regulation of lipolysis in adipocytes, and proximal tubule bicarbonate reclamation were significantly enriched in the signal transduction pathway category. The top three hub genes that resulted from the PPI network were FOXM1, UBE2C, and CDKN3. The results of survival analysis showed a close relationship between UBE2C and BC. The results of CCK-8 and transwell assays suggested that the proliferation and invasion of UBE2C knockdown cells were significantly inhibited (P < 0.050). The results of Western blot assay showed that the level of phosphorylated phosphatase and tensin homology deleted on chromosome 10 (p-PTEN) was obviously increased (P < 0.050), whereas the levels of phosphorylated protein kinase B (p-AKT), phosphorylated mammalian target of rapamycin (p-mTOR), and hypoxia-inducible factor-1 alpha (HIF-1α) were dramatically decreased (P < 0.050) in the UBE2C knockdown cell.
UBE2C can promote BC proliferation by activating the AKT/mTOR signaling pathway.
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