An afne space is a set consisting of points and vectors.A vector space(or linear space)is an afne space with a specied origin.For a given afne coordinate system,there exists a one-to-one correspondence between vectors...An afne space is a set consisting of points and vectors.A vector space(or linear space)is an afne space with a specied origin.For a given afne coordinate system,there exists a one-to-one correspondence between vectors and coordinates.In order to provide a theoretical basis for coordinate and frame transformations,and to simplify the transformation process in specic problem studies,the geometric product of vectors is redened(the geometric product of vectors is the sum of the negative inner product and the outer product of the vectors),thus the one-to-one correspondence relationship between unit vectors and imaginary units is established.According to Hurwitz's theorem,the vector space of the outer product is gotten and dened,and its dimension cannot be chosen arbitrarily.Based on Arthur Cayley's(1845)multiplication rules of octonions,transformation formulas for a seven-dimensional vector space and rotation matrices for coordinate frame transformations are derived.It is pointed out that the three-dimensional rotation matrices commonly used in astrometry and geodesy are special cases thereof.According to the redefinition of the geometric product of vectors,the multiplication rules of quaternions can be directly obtained,as well as the multiplication table of imaginary units of octonions.It is further indicated that the multiplication tables of imaginary units for octonions and hypercomplex numbers of higher dimensions are not unique.展开更多
背景与目的以人骨髓间充质干细胞(human bone marrow mesenchymal stem cells,hBMSCs)作为抑癌基因IL-24的细胞载体的研究目前未见报道。应用Gateway法构建共表达增强型绿色荧光蛋白(enhanced green uorescentprotein,EGFP)基因和IL-24...背景与目的以人骨髓间充质干细胞(human bone marrow mesenchymal stem cells,hBMSCs)作为抑癌基因IL-24的细胞载体的研究目前未见报道。应用Gateway法构建共表达增强型绿色荧光蛋白(enhanced green uorescentprotein,EGFP)基因和IL-24基因的慢病毒载体,探讨其对hBMSCs的转导情况,为今后肿瘤的基因治疗奠定基础。方法应用DNA重组技术构建含有IL-24和EGFP基因的慢病毒表达载体,并与慢病毒包装系统(ViraPowerTMLentiviralPackaging Mix)共转染293FT细胞,收集上清,纯化浓缩,测定重组病毒的滴度。取重组慢病毒感染hBMSCs,通过嘌呤霉素筛选并纯化hBMSCs,应用实时荧光定量PCR(quantitative PCR,qPCR)及ELISA法分别检测hBMSCs中IL-24mRNA及IL-24蛋白水平的表达情况。结果成功构建了共表达IL-24和EGFP基因的重组慢病毒载体,经包装、纯化及浓缩,病毒滴度为7.25×107PFU/mL。重组慢病毒转导hBMSCs后,通过筛选获得纯化,转导效率可达到100%。qPCR检测示:转导组IL-24mRNA表达明显高于未转导组(P<0.05);ELISA法检测显示转导组hBMSCs上清液IL-24蛋白表达40g/L,未转导组为阴性。结论构建的携带IL-24基因的重组慢病毒载体可有效转导hBMSCs,表达IL-24蛋白。展开更多
基金supported by the National Natural Science Foundation of China(No.42574047,No.12473068,No.41774039,No.42074002).
文摘An afne space is a set consisting of points and vectors.A vector space(or linear space)is an afne space with a specied origin.For a given afne coordinate system,there exists a one-to-one correspondence between vectors and coordinates.In order to provide a theoretical basis for coordinate and frame transformations,and to simplify the transformation process in specic problem studies,the geometric product of vectors is redened(the geometric product of vectors is the sum of the negative inner product and the outer product of the vectors),thus the one-to-one correspondence relationship between unit vectors and imaginary units is established.According to Hurwitz's theorem,the vector space of the outer product is gotten and dened,and its dimension cannot be chosen arbitrarily.Based on Arthur Cayley's(1845)multiplication rules of octonions,transformation formulas for a seven-dimensional vector space and rotation matrices for coordinate frame transformations are derived.It is pointed out that the three-dimensional rotation matrices commonly used in astrometry and geodesy are special cases thereof.According to the redefinition of the geometric product of vectors,the multiplication rules of quaternions can be directly obtained,as well as the multiplication table of imaginary units of octonions.It is further indicated that the multiplication tables of imaginary units for octonions and hypercomplex numbers of higher dimensions are not unique.
文摘背景与目的以人骨髓间充质干细胞(human bone marrow mesenchymal stem cells,hBMSCs)作为抑癌基因IL-24的细胞载体的研究目前未见报道。应用Gateway法构建共表达增强型绿色荧光蛋白(enhanced green uorescentprotein,EGFP)基因和IL-24基因的慢病毒载体,探讨其对hBMSCs的转导情况,为今后肿瘤的基因治疗奠定基础。方法应用DNA重组技术构建含有IL-24和EGFP基因的慢病毒表达载体,并与慢病毒包装系统(ViraPowerTMLentiviralPackaging Mix)共转染293FT细胞,收集上清,纯化浓缩,测定重组病毒的滴度。取重组慢病毒感染hBMSCs,通过嘌呤霉素筛选并纯化hBMSCs,应用实时荧光定量PCR(quantitative PCR,qPCR)及ELISA法分别检测hBMSCs中IL-24mRNA及IL-24蛋白水平的表达情况。结果成功构建了共表达IL-24和EGFP基因的重组慢病毒载体,经包装、纯化及浓缩,病毒滴度为7.25×107PFU/mL。重组慢病毒转导hBMSCs后,通过筛选获得纯化,转导效率可达到100%。qPCR检测示:转导组IL-24mRNA表达明显高于未转导组(P<0.05);ELISA法检测显示转导组hBMSCs上清液IL-24蛋白表达40g/L,未转导组为阴性。结论构建的携带IL-24基因的重组慢病毒载体可有效转导hBMSCs,表达IL-24蛋白。
