The formation mechanism for the body-centred regular icosahedral structure of Li13 cluster is proposed. The curve of the total energy versus the separation R between the nucleus at the centre and nuclei at the apexes ...The formation mechanism for the body-centred regular icosahedral structure of Li13 cluster is proposed. The curve of the total energy versus the separation R between the nucleus at the centre and nuclei at the apexes for this structure of Li13 has been calculated by using the method of Gou＇s modified arrangement channel quantum mechanics （MACQM）. The result shows that the curve has a minimal energy of-96.951 39 a.u. at R = 5.46ao. When R approaches to infinity, the total energy of thirteen lithium atoms has the value of-96.564 38 a.u. So the binding energy of Lii3 with respect to thirteen lithium atoms is 0.387 01 a.u. Therefore the binding energy per atom for Lii3 is 0.029 77 a.u. or 0.810 eV, which is greater than the binding energy per atom of 0.453 eV for Li2, 0.494 eV for Li3, 0.7878 eV for Li4. 0.632 eV for Lis, and 0.674 eV for Liv calculated by us previously. This means that the Li13 cluster may be formed stably in a body-centred regular icosahedral structure with a greater binding energy.展开更多
[Objective] The research aimed to clarify the genetic mechanism of special wide compatibility of GC13.[Method] The clustering analyses of GC13,five indica,five japonica and five wide compatibility varieties were carri...[Objective] The research aimed to clarify the genetic mechanism of special wide compatibility of GC13.[Method] The clustering analyses of GC13,five indica,five japonica and five wide compatibility varieties were carried out by using 70 SSR primers.[Result] GC13 was clustered into japonica group and had far genetic relationship with indica and wide compatibility variety.Two fertility loci were detected in GC13,in which one closely linked to RM225 on chromosome 6.According to the position on the chromosome,it speculated that this locus was allelic to S5.GC13 carried the allelic gene S5-n at this locus.The other locus closely linked to RM408 on chromosome 8 and was provisionally designated as Sg(t).At this locus,GC13 carried Sg(t)-i allelic gene,which was consistent with IR36.The effect of S5 locus was stronger than that of Sg(t).[Conclusion] The research laid the good foundation for using the wide compatibility line GC13 to breed the hybrid between subspecies.展开更多
Elemental abundance patterns of globular cluster stars can provide important clues for understanding cluster formation and early chemical evolution.The origin of the abundance patterns,however,still remains poorly und...Elemental abundance patterns of globular cluster stars can provide important clues for understanding cluster formation and early chemical evolution.The origin of the abundance patterns,however,still remains poorly understood.We have studied the impact of p-capture reaction cycles on the abundances of oxygen,sodium and aluminium considering nuclear reaction cycles of carbon-nitrogenoxygen-fluorine,neon-sodium and magnesium-aluminium in massive stars in stellar conditions of temperature range 2×107to 10×107K and typical density of 102gm cc-1.We have estimated abundances of oxygen,sodium and aluminium with respect to Fe,which are then assumed to be ejected from those stars because of rotation reaching a critical limit.These ejected abundances of elements are then compared with their counterparts that have been observed in some metal-poor evolved stars,mainly giants and red giants,of globular clusters M3,M4,M13 and NGC 6752.We observe an excellent agreement with[O/Fe]between the estimated and observed abundance values for globular clusters M3 and M4 with a correlation coefficient above 0.9 and a strong linear correlation for the remaining two clusters with a correlation coefficient above 0.7.The estimated[Na/Fe]is found to have a correlation coefficient above 0.7,thus implying a strong correlation for all four globular clusters.As far as[Al/Fe]is concerned,it also shows a strong correlation between the estimated abundance and the observed abundance for globular clusters M13 and NGC 6752,since here also the correlation coefficient is above 0.7 whereas for globular cluster M4 there is a moderate correlation found with a correlation coefficient above 0.6.Possible sources of these discrepancies are discussed.展开更多
旨在利用CRISPR/Cas9基因组编辑技术制备CD13基因敲除的IPEC-J2(猪空肠上皮细胞系)细胞,揭示细胞表面分化抗原13(cluster of differentiation 13,CD13)在肠道病原微生物感染肠道细胞中所起的作用。本研究在猪CD13基因第2外显子区域设计...旨在利用CRISPR/Cas9基因组编辑技术制备CD13基因敲除的IPEC-J2(猪空肠上皮细胞系)细胞,揭示细胞表面分化抗原13(cluster of differentiation 13,CD13)在肠道病原微生物感染肠道细胞中所起的作用。本研究在猪CD13基因第2外显子区域设计2个向导RNA(guide RNA,gRNA),命名为g3、g5,然后分别将g3和g5克隆到pX330-GFP和pX330-RFP载体骨架上,电转染IPEC-J2细胞,48 h后通过流式细胞术分选具有双荧光标记的细胞,培养并获得单克隆细胞,PCR扩增、测序,从而获得CD13基因纯合敲除的阳性细胞系。对获得的20个细胞单克隆进行PCR,并挑取部分克隆PCR产物测序,发现共有7个克隆发生了基因片段缺失,其中1个克隆为单等位基因片段缺失,3个克隆为双等位基因杂合片段缺失,3个克隆为双等位基因纯合片段敲除。本研究检测双等位基因纯合片段敲除细胞的蛋白表达水平,其结果显示,在该纯合敲除细胞中CD13蛋白几乎不表达,表明成功构建了CD13敲除的IPEC-J2细胞系。本研究获得的CD13基因敲除细胞系为探究CD13在猪肠道病原微生物感染肠道细胞中所起的作用奠定了基础。展开更多
基金supported by National Natural Science Foundation of China under Grant No.19974027
文摘The formation mechanism for the body-centred regular icosahedral structure of Li13 cluster is proposed. The curve of the total energy versus the separation R between the nucleus at the centre and nuclei at the apexes for this structure of Li13 has been calculated by using the method of Gou＇s modified arrangement channel quantum mechanics （MACQM）. The result shows that the curve has a minimal energy of-96.951 39 a.u. at R = 5.46ao. When R approaches to infinity, the total energy of thirteen lithium atoms has the value of-96.564 38 a.u. So the binding energy of Lii3 with respect to thirteen lithium atoms is 0.387 01 a.u. Therefore the binding energy per atom for Lii3 is 0.029 77 a.u. or 0.810 eV, which is greater than the binding energy per atom of 0.453 eV for Li2, 0.494 eV for Li3, 0.7878 eV for Li4. 0.632 eV for Lis, and 0.674 eV for Liv calculated by us previously. This means that the Li13 cluster may be formed stably in a body-centred regular icosahedral structure with a greater binding energy.
基金Supported by Guangxi Natural Science Fund Item(2010GXNSFD013035)Guangxi Science Fund Item(Guikeqing0832063)+1 种基金Guangxi Science Research and Technology Development Planning Item(Guikegong1123001-3C)National Science and Technology Support Planning Item(2007BAD68B01)
文摘[Objective] The research aimed to clarify the genetic mechanism of special wide compatibility of GC13.[Method] The clustering analyses of GC13,five indica,five japonica and five wide compatibility varieties were carried out by using 70 SSR primers.[Result] GC13 was clustered into japonica group and had far genetic relationship with indica and wide compatibility variety.Two fertility loci were detected in GC13,in which one closely linked to RM225 on chromosome 6.According to the position on the chromosome,it speculated that this locus was allelic to S5.GC13 carried the allelic gene S5-n at this locus.The other locus closely linked to RM408 on chromosome 8 and was provisionally designated as Sg(t).At this locus,GC13 carried Sg(t)-i allelic gene,which was consistent with IR36.The effect of S5 locus was stronger than that of Sg(t).[Conclusion] The research laid the good foundation for using the wide compatibility line GC13 to breed the hybrid between subspecies.
文摘Elemental abundance patterns of globular cluster stars can provide important clues for understanding cluster formation and early chemical evolution.The origin of the abundance patterns,however,still remains poorly understood.We have studied the impact of p-capture reaction cycles on the abundances of oxygen,sodium and aluminium considering nuclear reaction cycles of carbon-nitrogenoxygen-fluorine,neon-sodium and magnesium-aluminium in massive stars in stellar conditions of temperature range 2×107to 10×107K and typical density of 102gm cc-1.We have estimated abundances of oxygen,sodium and aluminium with respect to Fe,which are then assumed to be ejected from those stars because of rotation reaching a critical limit.These ejected abundances of elements are then compared with their counterparts that have been observed in some metal-poor evolved stars,mainly giants and red giants,of globular clusters M3,M4,M13 and NGC 6752.We observe an excellent agreement with[O/Fe]between the estimated and observed abundance values for globular clusters M3 and M4 with a correlation coefficient above 0.9 and a strong linear correlation for the remaining two clusters with a correlation coefficient above 0.7.The estimated[Na/Fe]is found to have a correlation coefficient above 0.7,thus implying a strong correlation for all four globular clusters.As far as[Al/Fe]is concerned,it also shows a strong correlation between the estimated abundance and the observed abundance for globular clusters M13 and NGC 6752,since here also the correlation coefficient is above 0.7 whereas for globular cluster M4 there is a moderate correlation found with a correlation coefficient above 0.6.Possible sources of these discrepancies are discussed.
