It has been reported that there was a linkage of 5S rRNA gene to 18S-5.8S-25S rRNA gene in a few of species in Ochrophyta.In regard to the usual two positions of linked 5S rDNA to the 3′end of 25S rDNA,two pairs of p...It has been reported that there was a linkage of 5S rRNA gene to 18S-5.8S-25S rRNA gene in a few of species in Ochrophyta.In regard to the usual two positions of linked 5S rDNA to the 3′end of 25S rDNA,two pairs of primers were designed for amplification to verify this linkage of two genes in a kelp cultivar of Saccharina japonica,one of species in Ochrophyta.This result supplemented the previous report that 5S rDNA was unlinked to 25S rDNA in this kelp.In order to simultaneously visualize this unlinkage of two genes,dual-color fluorescence in situ hybridization(FISH)technique was applied to the cytogenetics of S.japonica.Dual-color FISH images showed that two and four hybridization signals were present in the kelp gametophyte and sporophyte,respectively,metaphase nuclei hybridized simultaneously with the labeled probes of 18S rDNA and 5S rDNA.Both haploid and diploid karyotypes in decreasing length of chromosomes showed that 18S-5.8S-25S rDNA was localized at the interstitial region of Chromosome 23,whereas 5S rDNA resided at the sub-telomeric region of Chromosome 27.These karyotypes suggested that the kelp nuclear genome had only one locus of each rRNA gene,and their loci on different chromosomes indicated the physical unlinkage of 5S rDNA to 18S-5.8S-25S rDNA in this kelp.Therefore,dual-color FISH seems to be a powerful technique for the discrimination and pairing of chromosomes featured in both small size and nearly identical shape in S.japonica.展开更多
Three types of 4-bar linkages can trace the same coupler curve according to the cognate mechanism law. Based on the investigation of the relationship between dimensions of a linkage and the harmonic component characte...Three types of 4-bar linkages can trace the same coupler curve according to the cognate mechanism law. Based on the investigation of the relationship between dimensions of a linkage and the harmonic component characteristic parameters of the coupler curve of the linkage, it was found that six types of linkages are related to the same coupler curve, and they belong to two groups of cognate mechanisms, in which the coupler curves have the same shape and are symmetric. The relationships among the dimensional types of these six mechanisms are presented. The corresponding examples have also proved these conclusions. This work enriches the cognate mechanism law, and can result in more candidate mechanisms for mechanism dimensional synthesis.展开更多
Objectives To detect the polymorphism of D5S436 locus, and to carry out an amplified fragment length polymorphism (Amp FLP) genotyping linkage analysis in asthma families.Methods Allele and genotype frequencies of ...Objectives To detect the polymorphism of D5S436 locus, and to carry out an amplified fragment length polymorphism (Amp FLP) genotyping linkage analysis in asthma families.Methods Allele and genotype frequencies of the high polymorphic D5S436 locus were determined in 92 unrelated Chinese individuals by using polymerase chain reaction (PCR). The amplified fragments were separated by denaturing polyacrylamide gel electrophoresis and silver staining techniques. Results Eight alleles and 22 genotypes were observed in this population. The heterozygosity was 78.26%. The polymorphism information content (PIC) was 0.76. Amp FLP genotyping linkage analyses were carried out in four asthma families, demonstrating that the locus was inherited according to Mendel's law and had a clear result.Conclusion The PIC of D5S436 is high in Chinese individuals, so it could be used as a genetic marker of asthma in Chinese and might be useful in the gene diagnosis of asthma.展开更多
针对转动工作台与主轴成45°倾角的特殊双转台五轴联动数控机床,在分析机床结构和运动特点的基础上,提出了两种刀位后置处理坐标变换的计算方法,并推导出相应的坐标变换公式。该算法基于三维图形几何变换理论,解决了非正交旋转轴机...针对转动工作台与主轴成45°倾角的特殊双转台五轴联动数控机床,在分析机床结构和运动特点的基础上,提出了两种刀位后置处理坐标变换的计算方法,并推导出相应的坐标变换公式。该算法基于三维图形几何变换理论,解决了非正交旋转轴机床后置处理的坐标转换问题。经CAD/CAM软件C im atron E6.0的图形验证及DMU70V的机床验证,均表明该算法正确可靠。展开更多
基金Supported by the National Natural Science Foundation of China(Nos.41376136,31201992)the Double First-Class Discipline of Fisheries Science in China。
文摘It has been reported that there was a linkage of 5S rRNA gene to 18S-5.8S-25S rRNA gene in a few of species in Ochrophyta.In regard to the usual two positions of linked 5S rDNA to the 3′end of 25S rDNA,two pairs of primers were designed for amplification to verify this linkage of two genes in a kelp cultivar of Saccharina japonica,one of species in Ochrophyta.This result supplemented the previous report that 5S rDNA was unlinked to 25S rDNA in this kelp.In order to simultaneously visualize this unlinkage of two genes,dual-color fluorescence in situ hybridization(FISH)technique was applied to the cytogenetics of S.japonica.Dual-color FISH images showed that two and four hybridization signals were present in the kelp gametophyte and sporophyte,respectively,metaphase nuclei hybridized simultaneously with the labeled probes of 18S rDNA and 5S rDNA.Both haploid and diploid karyotypes in decreasing length of chromosomes showed that 18S-5.8S-25S rDNA was localized at the interstitial region of Chromosome 23,whereas 5S rDNA resided at the sub-telomeric region of Chromosome 27.These karyotypes suggested that the kelp nuclear genome had only one locus of each rRNA gene,and their loci on different chromosomes indicated the physical unlinkage of 5S rDNA to 18S-5.8S-25S rDNA in this kelp.Therefore,dual-color FISH seems to be a powerful technique for the discrimination and pairing of chromosomes featured in both small size and nearly identical shape in S.japonica.
基金the National Natural Science Foundation of China (Grant No.50135040) the Natural Science Fund of Shaanxi Province.
文摘Three types of 4-bar linkages can trace the same coupler curve according to the cognate mechanism law. Based on the investigation of the relationship between dimensions of a linkage and the harmonic component characteristic parameters of the coupler curve of the linkage, it was found that six types of linkages are related to the same coupler curve, and they belong to two groups of cognate mechanisms, in which the coupler curves have the same shape and are symmetric. The relationships among the dimensional types of these six mechanisms are presented. The corresponding examples have also proved these conclusions. This work enriches the cognate mechanism law, and can result in more candidate mechanisms for mechanism dimensional synthesis.
文摘Objectives To detect the polymorphism of D5S436 locus, and to carry out an amplified fragment length polymorphism (Amp FLP) genotyping linkage analysis in asthma families.Methods Allele and genotype frequencies of the high polymorphic D5S436 locus were determined in 92 unrelated Chinese individuals by using polymerase chain reaction (PCR). The amplified fragments were separated by denaturing polyacrylamide gel electrophoresis and silver staining techniques. Results Eight alleles and 22 genotypes were observed in this population. The heterozygosity was 78.26%. The polymorphism information content (PIC) was 0.76. Amp FLP genotyping linkage analyses were carried out in four asthma families, demonstrating that the locus was inherited according to Mendel's law and had a clear result.Conclusion The PIC of D5S436 is high in Chinese individuals, so it could be used as a genetic marker of asthma in Chinese and might be useful in the gene diagnosis of asthma.
文摘针对转动工作台与主轴成45°倾角的特殊双转台五轴联动数控机床,在分析机床结构和运动特点的基础上,提出了两种刀位后置处理坐标变换的计算方法,并推导出相应的坐标变换公式。该算法基于三维图形几何变换理论,解决了非正交旋转轴机床后置处理的坐标转换问题。经CAD/CAM软件C im atron E6.0的图形验证及DMU70V的机床验证,均表明该算法正确可靠。
