as a particularly promising and appealing technology because it has the potential to be both environmentally friendly and low cost. [2] This application creates demand for non-noble-metal-based electrocatalysts to substitute for the currently used highcost Pt catalysts; however, the development remains extremely challenging.High-entropy materials (HEMs) with unique microstructures and unprecedented physicochemical and mechanical properties have attracted a great deal of research interest in many different applied research fields. [3,4] High-entropy alloys (HEAs), as a prominent and already wellestablished group of HEMs, are generally defined as containing five or more principal components alloyed into a crystalline solid-solution phase with unexpected stability and chemical complexity. Many HEAs have demonstrated superior properties relative to traditional alloys, including unprecedented fracture toughness at cryogenic temperatures, [5] ultra-high mechanical performance overcoming the trade-off between strength and ductility, [6] and excellent catalytic selectivity and activities. [7] Largely because of their proximal arrangement of Electrochemical water splitting offers an attractive approach for hydrogen production. However, the lack of high-performance cost-effective electrocatalyst severely hinders its applications. Here, a multinary highentropy intermetallic (HEI) that possesses an unusual periodically ordered structure containing multiple non-noble elements is reported, which can serve as a highly efficient electrocatalyst for hydrogen evolution. This HEI exhibits excellent activities in alkalinity with an overpotential of 88.2 mV at a current density of 10 mA cm −2 and a Tafel slope of 40.1 mV dec −1 , which are comparable to those of noble catalysts. Theoretical calculations reveal that the chemical complexity and surprising atomic configurations provide a strong synergistic function to alter the electronic structure. Furthermore, the unique L1 2 -type ordered structure enables a specific site-isolation effect to further stabilize the H 2 O/H* adsorption/desorption, which dramatically optimizes the energy barrier of hydrogen evolution. Such an HEI strategy uncovers a new paradigm to develop novel electrocatalyst with superior reaction activities.As society seeks to drastically reduce the future usage of fossil fuels, molecular hydrogen is widely recognized as one of the most sustainable and regenerative alternative energy resources. [1] When considering the wide range of hydrogen production methods, electrochemical water splitting has been identifiedThe ORCID identification number(s) for the author(s) of this article can be found under https://doi.

High-tap-density silicon nanomaterials are highly desirable as anodes for lithium ion batteries, due to their small surface area and minimum first-cycle loss. However, this material poses formidable challenges to polymeric binder design. Binders adhere on to the small surface area to sustain the drastic volume changes during cycling; also the low porosities and small pore size resulting from this material are detrimental to lithium ion transport. This study introduces a new binder, poly(1-pyrenemethyl methacrylate-co-methacrylic acid) (PPyMAA), for a high-tap-density nanosilicon electrode cycled in a stable manner with a first cycle efficiency of 82%—a value that is further improved to 87% when combined with graphite material. Incorporating the MAA acid functionalities does not change the lowest unoccupied molecular orbital (LUMO) features or lower the adhesion performance of the PPy homopolymer. Our single-molecule force microscopy measurement of PPyMAA reveals similar adhesion strength between polymer binder and anode surface when compared with conventional polymer such as homopolyacrylic acid (PAA), while being electronically conductive. The combined conductivity and adhesion afforded by the MAA and pyrene copolymer results in good cycling performance for the high-tap-density Si electrode.

Understanding of H- and J-aggregation behaviors in fluorene-based polymers is significant both for determining the origin of various red-shifted emissions occurring in blue-emitting polyfluorenes and for developing polyfluorene-based device performance. In this contribution, we demonstrate a new theory of the H- and J-aggregation of polyfluorenes and oligofluorenes, and understand the influence of chromosphere aggregation on their photoluminescent properties. H- and J-aggregates are induced by a continuous increasing concentration of the oligofluorene or polyfluorene solution. A relaxed molecular configuration is simulated to illustrate the spatial arrangement of the bonding of fluorenes. It is indicated that the relaxed state adopts a 21 helical backbone conformation with a torsion angle of 18° between two connected repeat units. This configuration makes the formation of H- and J-aggregates through the strong π-π interaction between the backbone rings. A critical aggregation concentration is observed to form H- and J-aggregates for both polyfluorenes and oligofluorenes. These aggregates show large spectral shifts and distinct shape changes in photoluminescent excitation (PLE) and emission (PL) spectroscopy. Compared with "isolated" chromophores, H-aggregates induce absorption spectral blue-shift and fluorescence spectral red-shift but largely reduce fluorescence efficiency. "Isolated" chromophores not only refer to "isolated molecules" but also include those associated molecules if their conjugated backbones are not compact enough to exhibit perturbed absorption and emission. J-aggregates induce absorption spectral red-shift and fluorescence spectral red-shift but largely enhance fluorescence efficiency. The PLE and PL spectra also show that J-aggregates dominate in concentrated solutions. Different from the excimers, the H- and J-aggregate formation changes the ground-state absorption of fluorene-based chromophores. H- and J-aggregates show changeable absorption and emission derived from various interchain interactions, unlike the β phase, which has relatively fixed absorption and emission derived from an intrachain interaction.

Developing highly efficient and durable electrocatalysts for hydrogen evolution reaction (HER) under both alkaline and acidic media is crucial for the future development of a hydrogen economy. However, state-of-the-art high-performance electrocatalysts recently developed are based on carbon carriers mediated by binding noble elements and their complicated processing methods are a major impediment to commercialization. Here, inspired by the high-entropy alloy concept with its inherent multinary nature and using a glassy alloy design with its chemical homogeneity and tunability, we present a scalable strategy to alloy five equiatomic elements, PdPtCuNiP, into a high-entropy metallic glass (HEMG) for HER in both alkaline and acidic conditions. Surface dealloying of the HEMG creates a nanosponge-like architecture with nanopores and embedded nanocrystals that provides abundant active sites to achieve outstanding HER activity. The obtained overpotentials at a current density of 10 mA cm −2 are 32 and 62 mV in 1.0 m KOH and 0.5 m H 2 SO 4 solutions, respectively, outperforming most currently available electrocatalysts. Density functional theory reveals that a lattice distortion and the chemical complexity of the nanocrystals lead to a strong synergistic effect on the electronic structure that further stabilizes hydrogen proton adsorption/desorption. This HEMG strategy establishes a new paradigm for designing compositionally complex alloys for electrochemical reactions.

No abstract

Monks. EGFR-independent activation of p38 MAPK and EGFR-dependent activation of ERK1/2 are required for ROS-induced renal cell death. Am J Physiol Renal Physiol 287: F1049 -F1058, 2004. First published June 29, 2004 doi:10.1152/ajprenal.00132.2004,5-Tris-(glutathion-S-yl)hydroquinone (TGHQ), a reactive metabolite of the nephrotoxicant hydroquinone, induces the ROS-dependent activation of MAPKs, followed by histone H3 phosphorylation and oncotic cell death in renal proximal tubule epithelial cells (LLC-PK 1). Cell death and histone H3 phosphorylation are attenuated by pharmacological inhibition of p38 MAPK or ERK1/2 pathways. Because TGHQ, but not epidermal growth factor (EGF), induces histone H3 phosphorylation and cell death in LLC-PK 1 cells, we hypothesized that there are differences in the mechanisms by which TGHQ and EGF induce activation of the EGF receptor (EGFR). We therefore compared the relative ability of TGHQ, H 2O2, and EGF to activate EGFR and MAPKs and found that p38 MAPK activation is EGFR independent, whereas ERK1/2 activation occurs mainly through EGFR activation. TGHQ, H 2O2, and EGF induce different EGFR tyrosine phosphorylation profiles that likely influence the subsequent differential kinetics of MAPK activation. We next transfected LLC-PK 1 cells with a dominant negative p38 MAPK-expressing plasmid (pcDNA3-DNp38). TGHQ failed to induce phosphorylation of p38 MAPK and its substrate, MK-2, in pcDNA3-DNp38-transfected cells, indicating loss of function of p38 MAPK. In untransfected, pcDNA3 or pcDNA3-p38 (native)-transfected LLC-PK 1 cells, Hsp27 was intensively phosphorylated after TGHQ treatment, whereas in pcDNA3-DNp38-transfected cells, TGHQ failed to induce Hsp27 phosphorylation. Thus EGFR-independent p38 MAPK and EGFR-dependent ERK1/2 activation by TGHQ lead to the activation of two downstream signaling factors, i.e., histone H3 and Hsp27 phosphorylation, which have in common the potential ability to remodel chromatin. reactive oxygen species; epidermal growth factor receptor; mitogenactivated protein kinase; histone H3; heat shock protein 27 REACTIVE OXYGEN SPECIES (ROS) are associated with a variety of human diseases and toxicities associated with exposure to redox-active chemicals and/or their metabolites (4). 2,3,5-Tris-(glutathion-S-yl)hydroquinone (TGHQ) is a metabolite of hydroquinone (HQ) and contributes to HQ-mediated nephrotoxicity and nephrocarcinogenesis (21). Renal proximal tubule epithelial cells are especially susceptible to TGHQ-induced toxicity, probably due to the high activity of ␥-glutamyl transpeptidase (␥-GT), which catalyzes the metabolism of TGHQ activity and facilitates the subsequent cellular uptake of

Supplementary data are available at Bioinformatics online.

Fully crystallized alloys gained by annealing of metallic glasses show excellent rejuvenated catalytic capabilities for ultrafast activation of peroxide. As self-motivated galvanic cells form in the fully crystallized alloys, a grain growth contributing to extensively reduced grain boundaries greatly weakens electron trapping and promotes inner electron transportation, providing a significant insight into exploit novel catalysts.