MXenes are an emerging class of highly conductive two-dimensional (2D) materials with electrochemical storage features. Oriented macroscopic Ti3C2T x fibers can be fabricated from a colloidal 2D nematic phase dispersion. The layered conductive Ti3C2T x fibers are ideal candidates for constructing high-speed ionic transport channels to enhance the electrochemical capacitive charge storage performance. In this work, we assemble Ti3C2T x fibers with a high degree of flake orientation by a wet spinning process with controlled spinning speeds and morphology of the spinneret. In addition to the effects of cross-linking of magnesium ions between Ti3C2T x flakes, the electronic conductivity and mechanical strength of the as-prepared fibers have been improved to 7200 S cm–1 and 118 MPa, respectively. The oriented Ti3C2T x fibers present a volumetric capacitive charge storage capability of up to 1360 F cm–3 even in a Mg-ion based neutral electrolyte, with contributions from both nanofluidic ion transport and Mg-ion intercalation pseudocapacitance. The oriented 2D Ti3C2T x driven nanofluidic channels with great electronic conductivity and mechanical strength endows the MXene fibers with attributes for serving as conductive ionic cables and active materials for fiber-type capacitive electrochemical energy storage, biosensors, and potentially biocompatible fibrillar tissues.

Functionalizing carbon cathode surfaces with oxygen functional groups is an effective way to simultaneously tailor the fundamental properties and customize the electrochemical properties of aqueous Zn‐ion hybrid capacitors. In this work, the oxygen functional groups of chemically reduced graphene oxide (rGO) are systematically regulated via a series of reductants and varied experimental conductions. Carboxyl and carbonyl have been proven to significantly enhance the aqueous electrolyte wettability, Zn‐ion chemical adsorption, and pseudocapacitive redox activity by experimental study and computational analysis. The rGO cathode produced through hydrogen peroxide assisted hydrothermal reduction exhibits a specific capacitance of 277 F g−1 in 1 m ZnSO4 after optimization of surface oxygen functional groups. In addition, a quasi‐solid‐state flexible Zn‐ion hybrid capacitor (ZHC) with a polyacrylamide gel electrolyte and a high loading mass of 5.1 mg cm−2 are assembled. The as‐prepared quasi‐solid state ZHC can offer a superior areal capacitance of 1257 mF cm−2 and distinguished areal energy density of 342 µW h cm−2. The significant enhancement of redox activity and Zn‐ion storage capability by regulating the oxygen functional groups can shed light on the promotion of electrochemical charge storage properties even beyond protic electrolyte systems.

No abstract

Electrical characteristics of a 1 cm-long free-burning atmospheric-pressure argon arc are calculated by means of a model taking into account the existence of a near-cathode space-charge sheath and the discrepancy between the electron and heavy-particle temperatures in the arc column. The computed arc voltage exhibits a variation with the arc current I similar to the one revealed by the experiment and exceeds experimental values by no more than approximately 2 V in the current range 20-175 A. The sheath contributes about two-thirds or more of the arc voltage. The LTE model predicts a different variation of the arc voltage with I and underestimates the experimental values appreciably for low currents but by no more than approximately 2 V for I 120 A. However, the latter can hardly be considered as a proof of unimportance of the space-charge sheath at high currents: the LTE model overestimates both the resistance of the bulk of the arc column and the resistance of the part of the column that is adjacent to the cathode, and this overestimation to a certain extent compensates for the neglect of the voltage drop in the sheath. Furthermore, if the latter resistance were evaluated in the framework of the LTE model in an accurate way, then the overestimation would be still much stronger and the obtained voltage would significantly exceed those observed in the experiment.

The DNA repair enzyme 8‐oxoguanine DNA glycosylase‐1 (OGG1) is involved in early embryonic development, as well as in multiple conditions, including cardiac fibrosis, diabetes, and neurodegenerative diseases. But, function of OGG1 in pulmonary fibrosis was not entirely clear. In this study, we identified a novel function of OGG1 in the cell transformation process in pulmonary fibrosis. We demonstrated that OGG1 and Smad7 co‐localize and interact in A549 cells. Bleomycin‐induced pulmonary fibrosis was established in wild‐type (WT) and Ogg1‐/‐ mice. Upon treatment with transforming growth factor (TGF)‐β1, increased OGG1 expression was observed in WT mice with pulmonary fibrosis as well as in A549 cells, MRC‐5 cells, and primary rat type II alveolar epithelial cells. The increased expression of OGG1 promoted cell migration, while OGG1 depletion decreased migration ability. Expression of the transformation‐associated markers vimentin and alpha‐smooth muscle actin were also affected by OGG1. We also observed that OGG1 promoted TGF‐β1‐induced cell transformation and activated Smad2/3 by interacting with Smad7. The interaction between OGG1 and the TGF‐β/Smad axis modulates the cell transformation process in lung epithelial cells and fibroblasts. Moreover, we demonstrated that Ogg1 deficiency relieved pulmonary fibrosis in bleomycin‐treated mice. Ogg1 knockout decreased the bleomycin‐induced expression of Smad7 and phosphorylation of Smad2/3 in mice. These findings suggest that OGG1 has multiple biological functions in the pathogenesis of pulmonary fibrosis.

No abstract

No abstract

No abstract