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The production of hydrogen and oxygen via water electrolysis has become a sustainable and encouraging pathway for the establishment of new energy sources. Herein, we report the successful growth of hierarchical NiCo2O4‐carbon dots (CDs) nanoneedle arrays supported on nickel foam through a simple and environmentally benign hydrothermal self‐assembly technique. The designed material acts as a binder free electrode and shows bifunctional electrocatalytic activity for both hydrogen evolution reaction (HER) as well as oxygen evolution reaction (OER) in alkaline medium. An electrocatalyst sample with an optimal loading of CDs (25 mg) requires a low overpotential of 146 mV to achieve a current density of 10 mA/cm2 for the HER in an alkaline medium, whereas it requires an overpotential of 390 mV to achieve a current density of 50 mA/cm2 for the OER in the same alkaline medium. The excellent electrocatalytic activities of the sample with loading of CD can be ascribed due to the presence of large number of exposed active sites offered by CD/NiCo2O4 and the enhanced electron transfer processes occurring as a result of hierarchical structure composed of three‐dimensional nickel foam and the NiCo2O4−CDs nanoneedle arrays. Thus, the synthesis method introduced in this present work is a facile and cost‐effective approach for the construction of bifunctional electrocatalysts with high reactivity and excellent durability. [ABSTRACT FROM AUTHOR]

The research aims to identify the chemical constituents of endophytic fungi associated with Gynura japonica and their biological activities. Two endophytic fungi, labelled as GS-1 and GS-2, have been isolated from the leaves of G. japonica . They were cultivated on white rice media for their optimum cultivation time. Cultivated fungi were extracted with ethyl acetate and concentrated to give a crude extract. All crude extracts were evaluated for their phytochemical screening and assayed for their antibacterial and antioxidant activities. Based on the results, fungal GS-1 was the most potential fungus to produce bioactive secondary metabolites and identified as Dimorphiseta acuta . A bioactive compound was isolated from crude extract of fungal D. acuta and identified as emodin. To the best of our knowledge, the study of secondary metabolite and its biological activity of endophytic fungus colonised with the leaves of G. japonica is reported here for the first time.

A redox-responsive fluorescent carbon nanogel (FCN) was designed as a bioimaging probe for targeted drug delivery to cancer cells. FCN was synthesized by the carbonization of disulfide cross-linked hyaluronic acid in the fluorescence "on" mode, followed by the attachment of manganese oxide (MnO 2 ) nanosheets for fluorescence quenching (fluorescence "off"). We hypothesized that the fluorescence intensity of paclitaxel (PTX)-MnO 2 /FCN would suddenly increase (fluorescence "on") in the presence of a high level of glutathione (GSH) in cancer cells, owing to the reduction of MnO 2 to Mn 2+ and cleavage of the disulfide bond. Consequently, PTX would be released from the FCN system. Consistent with this hypothesis, the designed system recovered FCN fluorescence and triggered drug release through the cleavage of the disulfide bond by GSH. Moreover, PTX-MnO 2 /FCN demonstrated stable fluorescence intensity after GSH treatment, serving as a potential biosensor. PTX-MnO 2 /FCN exhibited excellent biocompatibility with normal cells and selectively targeted tumor cells, highlighting the therapeutic capabilities of this system. The developed PTX-MnO 2 /FCN structure may serve as a smart drug delivery system with diagnostic and therapeutic properties, good selectivity, and compatibility, and with excellent potential for biomedical applications., (Copyright © 2019 Elsevier B.V. All rights reserved.)