Large-scale exfoliation of defect-free and few-layer graphene by an inexpensive and environmentally-friendly route has been a significant challenge for a long time. Here we show that high-quality, few-layer graphene w...Large-scale exfoliation of defect-free and few-layer graphene by an inexpensive and environmentally-friendly route has been a significant challenge for a long time. Here we show that high-quality, few-layer graphene with high stability and low defect content can be obtained from natural graphite via a simple stirring process in urea/glycerol, with yields of up to 12 wt.%. We also demonstrate that this facile method can be applied to the exfoliation of other two-dimensional materials, such as molybdenum disulfide and boron nitride. The as-prepared graphene was further composited with polyvinylidene fluoride （PVDF） and the composite exhibited a low percolation threshold of 0.05 vol.%. The incorporation of low （4.5 vol.%） graphene amounts led to a significant increase in the thermal conductivity of the graphene-PVDF composites.展开更多
m^6A甲基转移酶(methyltransferase-like protein 3,METTL3)可调控m RNA的m6A甲基化水平,调节细胞蛋白质合成,实验室前期发现METTL3为乳腺上皮细胞乳合成重要调节分子,发挥泌乳调节作用。目前尚不清楚METTL3分子结构基础及其参与的调节...m^6A甲基转移酶(methyltransferase-like protein 3,METTL3)可调控m RNA的m6A甲基化水平,调节细胞蛋白质合成,实验室前期发现METTL3为乳腺上皮细胞乳合成重要调节分子,发挥泌乳调节作用。目前尚不清楚METTL3分子结构基础及其参与的调节机制。为揭示METTL3结构与功能关系,对METTL3蛋白作原核表达及纯化。研究采用PCR方法扩增牛mettl3基因完整CDS区,将CDS区插入原核表达载体p GEX-4T-1,异丙基硫代-β-D-半乳糖苷(IPTG)诱导METTL3蛋白大量表达,用8 mol·L-1尿素裂解包涵体,利用GST蛋白纯化试剂盒纯化诱导获得METTL3蛋白。SDS-PAGE证实GST-METTL3融合蛋白存在于包涵体内,试验获得高纯度GST-METTL3融合蛋白,为进一步研究METTL3蛋白在奶牛泌乳中作用提供重要依据。展开更多
文摘Large-scale exfoliation of defect-free and few-layer graphene by an inexpensive and environmentally-friendly route has been a significant challenge for a long time. Here we show that high-quality, few-layer graphene with high stability and low defect content can be obtained from natural graphite via a simple stirring process in urea/glycerol, with yields of up to 12 wt.%. We also demonstrate that this facile method can be applied to the exfoliation of other two-dimensional materials, such as molybdenum disulfide and boron nitride. The as-prepared graphene was further composited with polyvinylidene fluoride （PVDF） and the composite exhibited a low percolation threshold of 0.05 vol.%. The incorporation of low （4.5 vol.%） graphene amounts led to a significant increase in the thermal conductivity of the graphene-PVDF composites.
