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1. The aim of the present study was to examine if and how rat hypoxia-induced astrocytes affect the migration of neural progenitor cells (NPC) and to investigate the expression patterns of some chemokines, such as vascular endothelial growth factor (VEGF), stem cell factor (SCF), stromal-derived factor-1alpha (SDF-1alpha), fractalkine and monocyte chemoattractant protein-1 (MCP-1) in hypoxia-induced astrocytes and their contribution to NPC migration in vitro. 2. Costar Transwell inserts were used for the chemotaxis assay and quantified changes in the chemokines mRNA for between 0 h and 24 h posthypoxia were tested using real-time quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. The results showed that the chemotaxis of astrocyte cells exposed to hypoxia for 18 h reached a peak value, whereas the chemotaxis of astrocytes exposed to hypoxia for 24 h began to decrease compared with those exposed to hypoxia for 18 h. Hypoxia upregulated chemokine VEGF, SCF, SDF-1alpha and MCP-1 expression in a time-dependent manner but downregulated fractalkine expression in astrocytes. In addition, the time points of the peak expressions for VEGF, SCF, SDF-1alpha and MCP-1 were similar to the time point of maximum NPC migration. 3. Specific inhibitors that block the binding of specific chemokines to its receptors were used for analysing the contribution of the chemokine to NPC migration. When VEGF, SCF, SDF-1alpha and MCP-1 were each inhibited independently, NPC migration was reduced. When they were inhibited together, NPC migration was obviously inhibited compared with both the control and single-block cultures, which implies that the migratory effect of hypoxia-induced astrocytes was synergetic by several chemokines. 4. In conclusion, we demonstrated the time-dependent manner of NPC migration promotion by hypoxia-induced astrocytes. We also provide evidence that soluble factors, such as VEGF, SCF, SDF-1alpha and MCP-1, released from astrocytes, direct the migration of NPC under hypoxic circumstances. Given that astrocytes were activated to all hypoxia-ischaemia diseases, these results indicate an important role for astrocytes in directing NPC replacement therapy in the central nervous system.

The layered manganese dioxide (δ-type MnO2) film electrodeposited on carbon cloth (CC) functioned as a cathode in aqueous zinc-ion batteries. Battery performance was notably improved by doping MnO2 layers with cobalt and the CC surface with nitrogen. The δ-MnO2 interlayer accommodated Zn2+ ions in the as-deposited state and thus could act as an intercalation host during the discharging process. The Co-doped MnO2 film on the nitrogen-doped CC delivered a discharge capacity as high as 280 mA h g–1 at a specific current of 1.2 A g–1 for 600 charge/discharge cycles, while the discharge capacity did not exceed 30 mA h g–1 even at a specific current as high as 10.5 A g–1. These values are superior to those observed in the absence of doping, demonstrating the positive impact of Co- and N-doping into the MnO2 layers and the CC substrate on the cycling stability and rate capability.

In this study, we show from helium (He) plasma irradiation to tantalum and iron surfaces that morphology changes in nanoscale occur on the both metals. In particular, from systematic irradiation experiments, it is identified that fuzzy nanostructures are grown on the both metals. The necessary conditions for the morphology changes are discussed based on the experimental results in terms of the helium migration, the physical sputtering, and the shear modulus of materials. Because oxides or oxinitrides of iron and tantalum are thought of as visible light responsive photocatalytic materials, the present work shows wide potential of usage of plasmas as a tool to tailor photocatalytic materials.