Complex oxides and hydroxides of Ni, Co, and Mn from a precursor mixture were electrochemically deposited on both a cathode and an anode. On the Ni foam cathode, the complex metal hydroxides precipitated as nanolayers at -0.9 V. Simultaneously, the metal ions were oxidized and deposited as blocks on the Ni foam anode. While the concentrations of Ni(NO₃)₂ and Mn(NO₃)₂ were constant (80 mM for Ni²⁺ and 40 mM for Mn²⁺, respectively), the concentration of Co(NO₃)₂ was varied from 20 to 120 mM, which affected the morphology and electrochemical properties of the electrode: a Co:Ni:Mn molar ratio resulted in the highest specific capacitance (at a scan rate of 5 mV s^-1, 1800 F g^-1 for the cathode material and 720 F g^-1 for the anode material). This cathode material was assembled into symmetric supercapacitors, which demonstrated an excellent energy density of 39 Wh kg^-1 at a power density of 1300 W kg^-1 and a high capacitance retention of 90% after 3000 charge/discharge cycles. This high electrochemical performance was attributed to the optimized ratio of metal oxides, and this simple preparation strategy can be applied to other nanocomposites of complex metal oxides/hydroxides with desired characteristics for various applications.

We developed a two-step chemical bath deposition method followed by calcination for the production of ZnO/Co₃O₄ nanocomposites. In aqueous reactions, ZnO nanotubes were first densely grown on Ni foam, and then flat nanosheets of Co₃O₄ developed and formed a porous film. The aspect ratio and conductivity of the Co₃O₄ nanosheets were improved by the existence of the ZnO nanotubes, while the bath deposition from a mixture of Zn/Co precursors (one-step method) resulted in a wrinkled plate of Zn/Co oxides. As a supercapacitor electrode, the ZnO/Co₃O₄ nanosheets formed by the two-step method exhibited a high capacitance, and after being calcined at 450 °C, these nanosheets attained the highest specific capacitance (940 F g^–1) at a scan rate of 5 mV s^–1 in the cyclic voltammetry analysis. This value was significantly higher than those of single-component electrodes, Co₃O₄ (785 F g^–1) and ZnO (200 F g^–1); therefore, the presence of a synergistic effect was suggested. From the charge/discharge curves, the specific capacitance of ZnO/Co₃O₄ calcined at 450 °C was calculated to be 740 F g^–1 at a current density of 0.75 A g^–1, and 85.7% of the initial capacitance was retained after 1000 cycles. A symmetrical configuration exhibited a good cycling stability (Coulombic efficiency of 99.6% over 1000 cycles) and satisfied both the energy density (36.6 Wh kg^–1) and the power density (356 W kg^–1). Thus, the ZnO/Co₃O₄ nanocomposite prepared by this simple two-step chemical bath deposition and subsequent calcination at 450 °C is a promising material for pseudocapacitors. Furthermore, this approach can be applied to other metal oxide nanocomposites with intricate structures to extend the design possibility of active materials for electrochemical devices.

Objective. Inflammatory bowel disease (IBD) is a chronic debilitating disease associated with severe damage to the intestinal mucosa. Glucagon-like peptide-2 (GLP-2) is a potent and specific gastrointestinal growth factor. GLP-2 released from enteroendocrine cells is inactivated by dipeptidyl peptidase-4 (DPP-4). The aim of this study was to examine whether the DPP-4 inhibitor anagliptin improves experimental murine colitis. Material and methods. Male C57BL/6 mice aged 8 weeks were exposed to 1.5% dextran sulfate sodium (DSS) in drinking water for 7 days to induce experimental colitis. Anagliptin (0.1% in diet) was administrated from 2 days before the beginning of DSS to 7 days after the end of DSS. Changes in body weight and disease activity index were evaluated daily. Histological colitis severity, cellular proliferation and gene expression were determined in colonic tissues. Results. Treatment with anagliptin clearly improved body weight loss and disease activity index in the recovery phase. Histological score in the DSS + anagliptin group at day 14 was significantly lower than that in the DSS alone group. Treatment with anagliptin increased the Ki67-positive rate at days 10 and 14, and tended to increase insulin-like growth factor-1 mRNA expression in the DSS + anagliptin group. Conclusion. In this model of experimental colitis, the DPP-4 inhibitor anagliptin facilitated the restoration of mucosal damage, thereby resulting in the acceleration of healing. These findings suggest a new and novel therapeutic approach for the treatment of IBD.