随着点对点光纤量子密钥分发技术的成熟及其迅猛发展的商业化应用趋势,将量子信号与经典数据复用在同一根光纤中以提高系统效率和节约光纤资源成为近几年的研究热点之一。通过实验验证了两种共信道传输方案的噪声成分,仿真分析了噪声对...随着点对点光纤量子密钥分发技术的成熟及其迅猛发展的商业化应用趋势,将量子信号与经典数据复用在同一根光纤中以提高系统效率和节约光纤资源成为近几年的研究热点之一。通过实验验证了两种共信道传输方案的噪声成分,仿真分析了噪声对量子密钥分发系统性能的影响,并针对实验中存在的问题对噪声抑制方案进行评估分析,为经典―量子信号共信道传输商业化发展提供了实验支撑。实验结果表明:0 d Bm发射功率下,未进行噪声抑制的较远波段共信道传输系统密钥正向传输距离最远为75 km,采用窄带滤波技术的同波段共信道传输系统密钥正向传输距离最远达到164 km。该实验结果为未来在经典光网络中承载量子密钥分发系统提供了可行的共信道传输噪声抑制参考方案。展开更多
A full-length cDNA that encodes the rice chloroplastic glutamine synthetase 2 gene was isolated from a Minghui 63-normalized cDNA library; and GS2 rice transformants were obtained by an Agrobacterium tumefaciens-media...A full-length cDNA that encodes the rice chloroplastic glutamine synthetase 2 gene was isolated from a Minghui 63-normalized cDNA library; and GS2 rice transformants were obtained by an Agrobacterium tumefaciens-mediated transformation method. Transcripts of the GS2 gene were shown to accumulate at higher levels in the primary transgenic plants in the T0 generation; whereas plants in the T1 generation exhibited a co-suppressed chlorosis phenotype (yellow leaves) accompanied by decreased plant height, few tillers and decreased dry weight. The plants with yellow leaves also displayed a significant decline in GS2 messenger RNA (mRNA) transcriptional level and chlorophyll content; a decrease in total GS activities of ~50% was also found. Although there was no decrease in the concentration of total free amino acids, a change in the concentration of individual amino acids was observed. Our result also indicates a decreased metabolic level (soluble protein content and ammonium concentration) in GS2 co-suppressed plants. A correlation between chlorophyll content and GS2 mRNA expression level was also observed. The GS2 co-suppressed plants showed better performance when complemented with exogenous glutamine, indicating that the lack of an organic nitrogen pool inside the cell is the possible reason for the chlorosis phenotype of the transformants.展开更多
Trehalose is expected to be an alternative for toxic glycerol as a biocompatible cryoprotectant of red blood cells(RBCs).In this work,γ-poly(glutamic acid)(PGA)is modified by grafting hydrophobic phenethylamine,3,4-d...Trehalose is expected to be an alternative for toxic glycerol as a biocompatible cryoprotectant of red blood cells(RBCs).In this work,γ-poly(glutamic acid)(PGA)is modified by grafting hydrophobic phenethylamine,3,4-dimethoxyphenylethylamine and dodecylamine,respectively.The graft-modified PGA can significantly enhance cryosurvival of RBCs in combination with trehalose.Analyses of dynamic light scattering,hemolysis assay,atomic force microscope and confocal laser scanning microscope suggest that the modified PGA polymers can self-assemble into nanoparticles in phosphate buffer saline solutions at the pH range of 6.0–7.4,and exhibit membrane-disruptive activity due to hydrogen bond,conjugation and hydrophobic interactions with cell membranes.It is assumed that the modified PGA polymers can improve the cryosurvival of RBCs by promoting membrane permeability of trehalose.Among the three graft-modified polymers,phenethylamine-grafted PGA(PGA-g-PEA)can significantly increase the intracellular trehalose-loading content to 11.3±2.4 m M at pH 7.4,much higher than the value0.17±0.66 m M when trehalose is used without any polymers.In view of the aforementioned merit,the cryosurvival rate of sheep RBCs is increased to about 90%by incubation with 1.0 mg mL-1 PGA-g-PEA and 0.36 M trehalose.In vitro cell culture of L929 fibroblasts demonstrates low cytotoxicity of PGA-g-PEA.Therefore,hydrophobic PEA-modified PGA with enhanced intracellular trehalose-loading ability can be potentially applied in glycerol-free RBC cryopreservation or other related biomacromolecule delivery systems.展开更多
Using a cDNA microarray consisting of 9198 expressed sequence tags,we surveyed the gene expression profiles in shoots and roots of a rice hybrid,Liangyoupei 9 and its parents Peiai 64s and 93-11 at 72 h after germinat...Using a cDNA microarray consisting of 9198 expressed sequence tags,we surveyed the gene expression profiles in shoots and roots of a rice hybrid,Liangyoupei 9 and its parents Peiai 64s and 93-11 at 72 h after germination.A total of 8587 sequences had detectable signals in both shoots and roots of the three genotypes.A total of 1571 sequences exhibited significant(P<0.01)expression differences in shoots or roots among the three genotypes,of which 121 showed expression poly-morphisms in both shoots and roots,and 870 revealed significant expression differences between the hybrid and one of the parents.The expression polymorphism of the sequences was associated with the functional categories of the sequences.They occurred more frequently in categories of carbohy-drate,energy and lipid metabolisms and stress response than expected,while less frequently in categories of amino acid metabolism,transcription and translation regulation,and signal transduction.A total of 214 sequences exhibited significant(P<0.05)mid-parent heterosis in expression,of which 117 had homology to genes with known functions,assigned in the categories of basic metabolism,genetic information processing,cell growth and death,signal transduction,transportation and stress response.The results may provide useful information for exploring the relationship between gene expression polymorphism and phenotypic variation,and for characterizing the molecular mechanism of seedling development and heterosis in rice.展开更多
More and more studies demonstrate that a great deal of interactions among the quantitative trait loci (QTLs) are far more than those detected by single markers. A correlation method was proposed for estimating the int...More and more studies demonstrate that a great deal of interactions among the quantitative trait loci (QTLs) are far more than those detected by single markers. A correlation method was proposed for estimating the interactions of multiple QTLs detected by multi-markers in several mapping populations. Genetic implication of this method and usage were discussed.展开更多
Recently,a joint research team led by Chuxiong Zhuang of South China Agricultural University and Xiaofeng Cao of Institute of Genetics and Development Biology,Chinese Academy of Sciences published their work on the cl...Recently,a joint research team led by Chuxiong Zhuang of South China Agricultural University and Xiaofeng Cao of Institute of Genetics and Development Biology,Chinese Academy of Sciences published their work on the cloning and molecular characterization of the gene thermosensitive genic male sterile 5(tms5)in rice in Nature Communications[1].This is the result of a long-term collaboration representing an important advance in male sterility research in crops.展开更多
文摘随着点对点光纤量子密钥分发技术的成熟及其迅猛发展的商业化应用趋势,将量子信号与经典数据复用在同一根光纤中以提高系统效率和节约光纤资源成为近几年的研究热点之一。通过实验验证了两种共信道传输方案的噪声成分,仿真分析了噪声对量子密钥分发系统性能的影响,并针对实验中存在的问题对噪声抑制方案进行评估分析,为经典―量子信号共信道传输商业化发展提供了实验支撑。实验结果表明:0 d Bm发射功率下,未进行噪声抑制的较远波段共信道传输系统密钥正向传输距离最远为75 km,采用窄带滤波技术的同波段共信道传输系统密钥正向传输距离最远达到164 km。该实验结果为未来在经典光网络中承载量子密钥分发系统提供了可行的共信道传输噪声抑制参考方案。
基金supported in part by grants from the National Basic Research Program of China (Grant No. 2005CB120905)the National Special Key Project of China on Functional Genomics of Major Plants and Animalsthe National Natural Science Foundation of China and the Cultivation Fund of the Key Scientific and Technical Innovation Project, Ministry of Education of China (Grant No. 707045)
文摘A full-length cDNA that encodes the rice chloroplastic glutamine synthetase 2 gene was isolated from a Minghui 63-normalized cDNA library; and GS2 rice transformants were obtained by an Agrobacterium tumefaciens-mediated transformation method. Transcripts of the GS2 gene were shown to accumulate at higher levels in the primary transgenic plants in the T0 generation; whereas plants in the T1 generation exhibited a co-suppressed chlorosis phenotype (yellow leaves) accompanied by decreased plant height, few tillers and decreased dry weight. The plants with yellow leaves also displayed a significant decline in GS2 messenger RNA (mRNA) transcriptional level and chlorophyll content; a decrease in total GS activities of ~50% was also found. Although there was no decrease in the concentration of total free amino acids, a change in the concentration of individual amino acids was observed. Our result also indicates a decreased metabolic level (soluble protein content and ammonium concentration) in GS2 co-suppressed plants. A correlation between chlorophyll content and GS2 mRNA expression level was also observed. The GS2 co-suppressed plants showed better performance when complemented with exogenous glutamine, indicating that the lack of an organic nitrogen pool inside the cell is the possible reason for the chlorosis phenotype of the transformants.
基金supported by the National Natural Science Foundation of China(Grant No.51773150)。
文摘Trehalose is expected to be an alternative for toxic glycerol as a biocompatible cryoprotectant of red blood cells(RBCs).In this work,γ-poly(glutamic acid)(PGA)is modified by grafting hydrophobic phenethylamine,3,4-dimethoxyphenylethylamine and dodecylamine,respectively.The graft-modified PGA can significantly enhance cryosurvival of RBCs in combination with trehalose.Analyses of dynamic light scattering,hemolysis assay,atomic force microscope and confocal laser scanning microscope suggest that the modified PGA polymers can self-assemble into nanoparticles in phosphate buffer saline solutions at the pH range of 6.0–7.4,and exhibit membrane-disruptive activity due to hydrogen bond,conjugation and hydrophobic interactions with cell membranes.It is assumed that the modified PGA polymers can improve the cryosurvival of RBCs by promoting membrane permeability of trehalose.Among the three graft-modified polymers,phenethylamine-grafted PGA(PGA-g-PEA)can significantly increase the intracellular trehalose-loading content to 11.3±2.4 m M at pH 7.4,much higher than the value0.17±0.66 m M when trehalose is used without any polymers.In view of the aforementioned merit,the cryosurvival rate of sheep RBCs is increased to about 90%by incubation with 1.0 mg mL-1 PGA-g-PEA and 0.36 M trehalose.In vitro cell culture of L929 fibroblasts demonstrates low cytotoxicity of PGA-g-PEA.Therefore,hydrophobic PEA-modified PGA with enhanced intracellular trehalose-loading ability can be potentially applied in glycerol-free RBC cryopreservation or other related biomacromolecule delivery systems.
基金supported by the National Program on the Development of Basic Research(Grant No.2001CB1088)the National Special Key Project of Functional Genomics and Biochips(Grant No.2002AA2Z1002)the National Natural Science Foundation of China(Grant No.30321005).
文摘Using a cDNA microarray consisting of 9198 expressed sequence tags,we surveyed the gene expression profiles in shoots and roots of a rice hybrid,Liangyoupei 9 and its parents Peiai 64s and 93-11 at 72 h after germination.A total of 8587 sequences had detectable signals in both shoots and roots of the three genotypes.A total of 1571 sequences exhibited significant(P<0.01)expression differences in shoots or roots among the three genotypes,of which 121 showed expression poly-morphisms in both shoots and roots,and 870 revealed significant expression differences between the hybrid and one of the parents.The expression polymorphism of the sequences was associated with the functional categories of the sequences.They occurred more frequently in categories of carbohy-drate,energy and lipid metabolisms and stress response than expected,while less frequently in categories of amino acid metabolism,transcription and translation regulation,and signal transduction.A total of 214 sequences exhibited significant(P<0.05)mid-parent heterosis in expression,of which 117 had homology to genes with known functions,assigned in the categories of basic metabolism,genetic information processing,cell growth and death,signal transduction,transportation and stress response.The results may provide useful information for exploring the relationship between gene expression polymorphism and phenotypic variation,and for characterizing the molecular mechanism of seedling development and heterosis in rice.
基金This research was supported by the National Natural Science Foundation of China (Grant No. 30070425).
文摘More and more studies demonstrate that a great deal of interactions among the quantitative trait loci (QTLs) are far more than those detected by single markers. A correlation method was proposed for estimating the interactions of multiple QTLs detected by multi-markers in several mapping populations. Genetic implication of this method and usage were discussed.
文摘Recently,a joint research team led by Chuxiong Zhuang of South China Agricultural University and Xiaofeng Cao of Institute of Genetics and Development Biology,Chinese Academy of Sciences published their work on the cloning and molecular characterization of the gene thermosensitive genic male sterile 5(tms5)in rice in Nature Communications[1].This is the result of a long-term collaboration representing an important advance in male sterility research in crops.
