Nanoscale bimetallic Ni/Fe particles were synthesized from the reaction of sodium borohydride （NaBH4） with reduction of Ni^2＋ and Fe^2＋ in aqueous solution. The obtained Ni/Fe particles were characterized by TEM ...Nanoscale bimetallic Ni/Fe particles were synthesized from the reaction of sodium borohydride （NaBH4） with reduction of Ni^2＋ and Fe^2＋ in aqueous solution. The obtained Ni/Fe particles were characterized by TEM （transmission electron microscope）, XRD （X-ray diffractometer）, and N2-BET. The dechlorination activity of the Ni/Fe was investigated using p-chlorophenol （p-CP） as a probe agent. Results demonstrated that the nanoscale Ni/Fe could effectively dechlorinate p-CP at relatively low metal to solution ratio of 0.4 g/L （Ni 5 wt%）. The target with initial concentration ofp-CP 0.625 mmol/L was dechlorinted completely in 60 rain under ambient temperature and pressure. Factors affecting dechlorination efficiency, including reaction temperature, pH, Ni loading percentage over Fe, and metal to solution ratio, were investigated. The possible mechanism of dechlorination ofp-CP was proposed and discussed. The pseudo-first- order reaction took place on the surface of the Ni/Fe bimetallic particles, and the activation energy of the dechlorination reaction was determined to be 21.2 kJ/mol at the temperature rang of 287-313 K.展开更多
The past decade has witnessed a surge of interest in exploring emergent particles in condensed matter systems.Novel particles,emerged as excitations around exotic band degeneracy points,continue to be reported in real...The past decade has witnessed a surge of interest in exploring emergent particles in condensed matter systems.Novel particles,emerged as excitations around exotic band degeneracy points,continue to be reported in real materials and artificially engineered systems,but so far,we do not have a complete picture on all possible types of particles that can be achieved.Here,via systematic symmetry analysis and modeling,we accomplish a complete list of all possible particles in time-reversal-invariant systems.This includes both spinful particles such as electron quasiparticles in solids,and spinless particles such as phonons or even excitations in electric-circuit and mechanical networks.We establish detailed correspondence between the particle,the symmetry condition,the effective model,and the topological character.This obtained encyclopedia concludes the search for novel emergent particles and provides concrete guidance to achieve them in physical systems.展开更多
目的分析我国GⅡ.4型诺如病毒(norovirus,NoV)GZ19株的进化特征,并明确其结合组织血型抗原(histoblood group antigens,HBGAs)受体的能力和方式。方法根据GZ19株中的ORF2区序列,构建进化树,并分析其在HBGAs结合位点(HBGA binding sites,...目的分析我国GⅡ.4型诺如病毒(norovirus,NoV)GZ19株的进化特征,并明确其结合组织血型抗原(histoblood group antigens,HBGAs)受体的能力和方式。方法根据GZ19株中的ORF2区序列,构建进化树,并分析其在HBGAs结合位点(HBGA binding sites,HBSs)和关键阻断表位的氨基酸序列。采用原核表达系统表达P颗粒并进行纯化,获得的蛋白经SDS-PAGE和间接ELISA法鉴定后,采用唾液结合试验和寡糖结合试验分析P颗粒的糖结合特征。结果GZ19株属于GⅡ.4 Sydney[P31]谱系,其受体结合位点和阻断表位的氨基酸序列相对保守,与近5年其他GⅡ.4Sydney[P31]毒株具有较高的同源性,而与GⅡ.4 Sydney 2012原型株和GⅡ.4 Sydney[P16]株的差异较大。P颗粒仅与A、B、O、AB分泌型唾液和H-di寡糖结合。结论GZ19株代表目前GⅡ.4 Sydney[P31]NoV的进化方向,P颗粒的成功表达及其与HBGAs受体的结合特征分析,为研究我国GⅡ.4 NoVs的流行进化规律及疫苗开发奠定了基础。展开更多
诺如病毒(norovirus,NVs)是非细菌性急性胃肠炎的主要病原,严重地威胁着婴幼儿、老年人和公共场所人群的健康。疫苗是目前临床预防由NVs引发急性胃肠炎的主要策略之一。按番茄偏爱密码子设计合成编码诺如病毒(VA387)衣壳蛋白——P粒子基...诺如病毒(norovirus,NVs)是非细菌性急性胃肠炎的主要病原,严重地威胁着婴幼儿、老年人和公共场所人群的健康。疫苗是目前临床预防由NVs引发急性胃肠炎的主要策略之一。按番茄偏爱密码子设计合成编码诺如病毒(VA387)衣壳蛋白——P粒子基因PGENE(1 002bp),为便于纯化,PGENE的5'端包含编码6×his-tag的DNA序列;构建原核表达载体PET32a-PGENE并导入BL21。在16℃条件下,用终浓度1mmol/L的IPTG(isopropylβ-D-1-thiogalactopyranoside)诱导表达,Ni-NTA树脂亲和层析法纯化获得P粒子,并通过Western blot加以确认;在透射电子显微镜(transmission electron microscopy,TEM)下观察到了球形P粒子成功组装;用该蛋白免疫小鼠,成功获得了活性的抗体血清。为后续用番茄研制口服诺如病毒疫苗奠定了基础。展开更多
基金Project supported by the National Basic Research Program (973) of China(No. 2003CB415006)the National Natural Science Foundation of China (No. 20337020)
文摘Nanoscale bimetallic Ni/Fe particles were synthesized from the reaction of sodium borohydride （NaBH4） with reduction of Ni^2＋ and Fe^2＋ in aqueous solution. The obtained Ni/Fe particles were characterized by TEM （transmission electron microscope）, XRD （X-ray diffractometer）, and N2-BET. The dechlorination activity of the Ni/Fe was investigated using p-chlorophenol （p-CP） as a probe agent. Results demonstrated that the nanoscale Ni/Fe could effectively dechlorinate p-CP at relatively low metal to solution ratio of 0.4 g/L （Ni 5 wt%）. The target with initial concentration ofp-CP 0.625 mmol/L was dechlorinted completely in 60 rain under ambient temperature and pressure. Factors affecting dechlorination efficiency, including reaction temperature, pH, Ni loading percentage over Fe, and metal to solution ratio, were investigated. The possible mechanism of dechlorination ofp-CP was proposed and discussed. The pseudo-first- order reaction took place on the surface of the Ni/Fe bimetallic particles, and the activation energy of the dechlorination reaction was determined to be 21.2 kJ/mol at the temperature rang of 287-313 K.
基金supported by the National Key R&D Program of China(2020YFA0308800,2016YFA0300600,and 2017YFB0701600)the National Natural Science Foundation of China(11734003,12061131002,12004028,and 12004035)+3 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(XDB30000000)the China Postdoctoral Science Foundation(2020M670106)the Singapore Ministry of Education AcRF Tier 2(MOE2019-T2-1-001)Beijing Institute of Technology Research Fund Program for Young Schola。
文摘The past decade has witnessed a surge of interest in exploring emergent particles in condensed matter systems.Novel particles,emerged as excitations around exotic band degeneracy points,continue to be reported in real materials and artificially engineered systems,but so far,we do not have a complete picture on all possible types of particles that can be achieved.Here,via systematic symmetry analysis and modeling,we accomplish a complete list of all possible particles in time-reversal-invariant systems.This includes both spinful particles such as electron quasiparticles in solids,and spinless particles such as phonons or even excitations in electric-circuit and mechanical networks.We establish detailed correspondence between the particle,the symmetry condition,the effective model,and the topological character.This obtained encyclopedia concludes the search for novel emergent particles and provides concrete guidance to achieve them in physical systems.
文摘诺如病毒(norovirus,NVs)是非细菌性急性胃肠炎的主要病原,严重地威胁着婴幼儿、老年人和公共场所人群的健康。疫苗是目前临床预防由NVs引发急性胃肠炎的主要策略之一。按番茄偏爱密码子设计合成编码诺如病毒(VA387)衣壳蛋白——P粒子基因PGENE(1 002bp),为便于纯化,PGENE的5'端包含编码6×his-tag的DNA序列;构建原核表达载体PET32a-PGENE并导入BL21。在16℃条件下,用终浓度1mmol/L的IPTG(isopropylβ-D-1-thiogalactopyranoside)诱导表达,Ni-NTA树脂亲和层析法纯化获得P粒子,并通过Western blot加以确认;在透射电子显微镜(transmission electron microscopy,TEM)下观察到了球形P粒子成功组装;用该蛋白免疫小鼠,成功获得了活性的抗体血清。为后续用番茄研制口服诺如病毒疫苗奠定了基础。
