1,917 research outputs found

    Chemical Modification of Fast-Grown Poplar by Urea Formaldehyde and Polyacrylic Resin

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    In this study, methylolurea and polyacrylic resin were used to modify fast-grown poplar. The dimensional stability and mechanical properties of natural and modified wood were investigated. Also, the modified samples were characterized by scanning electron microscopy, X-ray diffraction (XRD), Fourier transform IR spectroscopy (FTIR), and thermogravimetric analysis (TGA). The results showed that the chemical modifier was impregnated into the wood inner structure, which improved the chemical and mechanical performance of wood. FTIR demonstrated that the hydroxyl groups of wood were decreased, which decreased the water absorption of natural wood. XRD tests indicated that the crystallinity of wood increased but the structure of cellulose was not disrupted after modification. TGA analysis showed that the thermal stability of the hemicelluloses and cellulose was enhanced after modification. The prepolymer was not only impregnated into the wood cell, but also reacted with the wood fiber. A crosslinking reaction occurred between the wood modifier and wood fiber

    Expression of MiR-9 promotes proliferation, migration and differentiation of human neural stem cells

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    Purpose: To investigate the effect of miR-9 on the proliferation, differentiation and migration of human neural stem cells (NSCs).Methods: The expression of miR-9 was investigated by quantitative real-time polymerase chain reaction (RT-PCR). Cell proliferation was assessed by cell counting kit-8 (CCK8) assay, while cell migration was studied by Transwell assay. The effect of miR-9 on differentiation of NSCs was investigated by western blot analysis of key differentiation marker proteins. Protein expression was determined by western blotting.Results: Transfection and over-expression of miR-9 in NSCs significantly enhanced the proliferation of NSCs (p < 0.05) in a time-dependent manner, as was evident from CCK8 assay data. MiR-9 overexpression caused down-regulation of Nestin and SOX-2, and up-regulation of Tuj-1 and MAP-2. The migration of NSCs was 37 % in the cells transfected with empty vector, compared to 68 % in the cells transfected with miR-9. This effect of miR-9 on cell migration was accompanied by up-regulation of matrix metallopeptidase 9 (MMP-9) and matrix metallopeptidase 2 (MMP-2).Conclusion: These results show that miR-9 promotes the proliferation, differentiation and migration of NSCs, and thus may be an important drug target for the generation of NSCs.Keywords: Neural stem cells, MicroRNA, Mir-9, Migration, Differentiation, Proliferatio

    Nutrients removal performance and sludge properties using anaerobic fermentation slurry from food waste as an external carbon source for wastewater treatment

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    © 2018 Elsevier Ltd Enhancement of nitrogen and phosphate removal using thermophilic fermentation slurry from food waste (FSFW) as external carbon source was investigated. Based on the batch tests, the soluble and particulate fractions of the FSFW acted as easily and slowly biodegradable carbon sources, respectively, and the fermented slurry showed the combined nutrients removal properties of soluble and solid organics. During the long-term operation of a sequencing batch reactor (SBR) with FSFW for wastewater treatment, the sludge particle size increased obviously, the bacterial metabolic capacity improved significantly, and some functional microorganisms were enriched selectively, which significantly promoted the nitrogen removal efficiency (approximately 90%) by enhancing the anoxic denitrification and simultaneous nitrification and denitrification (SND) processes. Moreover, high phosphate removal efficiency (above 98%) was achieved through the aerobic and anoxic phosphate accumulation processes. Thus, using the FSFW as supplementary carbon source is a suitable solution for both food waste disposal and wastewater treatment
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