12,396 research outputs found

    Effects of cordycepin on the microglia-overactivation-induced impairments of growth and development of hippocampal cultured neurons

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    © 2015 Peng et al. Microglial cells are normally activated in response to brain injury or immunological stimuli to protect central nervous system (CNS). However, over-activation of microglia conversely amplifies the inflammatory effects and mediates cellular degeneration, leading to the death of neurons. Recently, cordycepin, an active component found in Cordyceps militarisa known as a rare Chinese caterpillar fungus, has been reported as an effective drug for treating inflammatory diseases and cancer via unclear mechanisms. In this study, we attempted to identify the anti-inflammatory role of cordycepin and its protective effects on the impairments of neural growth and development induced by microglial over-activation. The results indicate that cordycepin could attenuate the lipopolysaccharide (LPS)-induced microglial activation, evidenced by the dramatically reduced release of TNF-α and IL-1β, as well as the down-regulation of mRNA levels of iNOS and COX-2 after cordycepin treatment. Besides, cordycepin reversed the LPS-induced activation of NF-κB pathway, resulting in antiinflammatory effects. Furthermore, by employing the conditioned medium (CM), we found cordycepin was able to recover the impairments of neural growth and development in the primary hippocampal neurons cultured in LPS-CM, including cell viability, growth cone extension, neurite sprouting and outgrowth as well as spinogenesis. This study expands our knowledge of the anti-inflammatory function of cordycepin and paves the way for the biomedical applications of cordycepin in the therapies of neural injuries

    Photocatalytic mineralisation of herbicide 2,4,5-trichlorophenoxyacetic acid: enhanced performance by triple junction Cu-TiO2-Cu2O and the underlying reaction mechanism

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    A mild and facile photodeposition method was used to fabricate novel Cu–TiO2–Cu2O composite photocatalysts. Due to the in situ rectifying charge carrier separation and enhanced conductivity, the composites present superior photocatalytic activity, leading to more than 90% mineralisation of the toxic 2,4,5-trichlorophenoxyacetic acid herbicide. This result was confirmed by both TOC and UV-vis absorption measurements. The effect of active radicals on the photodegradation of the herbicide was further investigated in order to clarify the underlying mechanism, based on which a hole-dominated photooxidation mechanism was proposed. These results not only offer a green and economical method for constructing triple junction photocatalyst materials, but also shed new insight on the rational design of a low cost and high-efficiency photocatalyst for environmental remediation

    Two-Step Sintering of Ceramics with Constant Grain-Size, II: BaTiO\u3csub\u3e3\u3c/sub\u3eand Ni–Cu–Zn Ferrite

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    We investigated the preparation of bulk dense nanocrystalline BaTiO3 and Ni–Cu–Zn ferrite ceramics using an unconventional two-step sintering strategy, which offers the advantage of not having grain growth while increasing density from about 75% to above 96%. Using nanosized powders, dense ferrite ceramics with a grain size of 200 nm and BaTiO3 with a grain size of 35 nm were obtained by two-step sintering. Like the previous studies on Y2O3, the different kinetics between densification diffusion and grain boundary network mobility leaves a kinetic window that can be utilized in the second-step sintering. Evidence indicates that low symmetry, ferroelectric structures still exist in nanograin BaTiO3 ceramics, and that saturation magnetization is the same in nanograin and coarse grain ferrite ceramics
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