最近阐明了水华蓝藻噬藻体PaV-LD(Planktothrix agardhii Virus isolated from Lake Donghu)的全基因组序列,这是一个含有142个ORF的双链DNA噬藻体。在此,我们对其主要衣壳蛋白基因073R,内肽酶和穿孔素基因123L-124L(PaV-LD基因组中两...最近阐明了水华蓝藻噬藻体PaV-LD(Planktothrix agardhii Virus isolated from Lake Donghu)的全基因组序列,这是一个含有142个ORF的双链DNA噬藻体。在此,我们对其主要衣壳蛋白基因073R,内肽酶和穿孔素基因123L-124L(PaV-LD基因组中两个相邻的ORF)进行了基因克隆与表达分析。将073R克隆后构建原核表达质粒pET-32a-073R,并用IPTG进行诱导表达,073R融合蛋白经纯化后,进行免疫小鼠制备抗体;通过Western blot检测经噬藻体感染宿主细胞后073R的表达时序,结果显示在宿主细胞裂解之初,即PaV-LD感染48h以后073R开始表达,表明073R是一个晚期基因;同时073R推导的氨基酸序列与34株噬藻(菌)体及2株藻病毒(感染真核藻的病毒)的主要衣壳蛋白的氨基酸序列进行序列比对,显示073R与无尾的藻病毒衣壳蛋白亲缘关系更近。PCR扩增内肽酶和穿孔素基因123L-124L,并构建质粒pOP123L-124L,将其转入模式藻集胞藻PCC6803细胞中,质粒pOP123L-124L与藻集胞藻PCC6803基因组发生重组,形成重组藻;测定了重组藻与野生藻的生长速率,并绘制生长曲线;制备超薄切片,进一步比较和观察重组藻与野生藻的超微结构的变化。结果显示重组藻与野生藻存在生长速率与超微形态的显著差异。展开更多
The paper proposes a new tool to measure the risk in financial market:PaV,which means the hap pening probability with the given loss magnitude,and utilizes Copula function to obtain its computing algorithm.Two cases a...The paper proposes a new tool to measure the risk in financial market:PaV,which means the hap pening probability with the given loss magnitude,and utilizes Copula function to obtain its computing algorithm.Two cases are illustrated for the promising applications of PaV.展开更多
According to the published nucleotide sequences,CP gene of barley yellow dwarf virus PAV(BYDV-PAV) was synthesized by reverse transcription polymerase chain reaction(RT-PCR).The reporter gene GFP was put to the downst...According to the published nucleotide sequences,CP gene of barley yellow dwarf virus PAV(BYDV-PAV) was synthesized by reverse transcription polymerase chain reaction(RT-PCR).The reporter gene GFP was put to the downstream of whole CP gene sequence of BYDV-PAV after double enzyme digestion,PCR identification and sequencing.The green fluorescence protein expression system of coat protein of BYDV-PAV was successfully constructed and expressed in Escherichia coli BL21(DE3)plysS.The expression product was confirmed by SDS-PAGE,Western blot analysis and fluorescence microscope.The fusion gene CP-GFP was expressed in the range of 15-22℃,but could not be expressed at 23-37℃.The results provided a base for studying on BYDV-PAV movement in aphid further.展开更多
For the most coastal areas where the air is very humid,study on the effect of humidity on the performance of asphalt has its practical significance.However,limited research has been done to investigate the effect of h...For the most coastal areas where the air is very humid,study on the effect of humidity on the performance of asphalt has its practical significance.However,limited research has been done to investigate the effect of humidity on rheological properties of asphalt.In this study,asphalt binders were aged in the pressure aging vessel(PAV)under different conditions of moisture and aging time.Then Dynamic Shear Rheometer(DSR)and Bending Beam Rheometer(BBR)measurements were conducted to obtain the parameters relating to the complex modulus,phase angle,failure temperature,and creep stiffness.It was found that the low temperature performance decreased as evidenced by the results of the creep stiffness.While there were no significant differences among conditioned binders based on complex modulus G*and phase angleδ,it was found that theδvalue increased when the humidity increased from 0% to 80% ,and then theδvalue decreased when the humidity increased to 100% .In addition,the results of the failure temperature indicated that the humidity of 80% would be a critical point for the high temperature performance of the asphalt binders.展开更多
文摘最近阐明了水华蓝藻噬藻体PaV-LD(Planktothrix agardhii Virus isolated from Lake Donghu)的全基因组序列,这是一个含有142个ORF的双链DNA噬藻体。在此,我们对其主要衣壳蛋白基因073R,内肽酶和穿孔素基因123L-124L(PaV-LD基因组中两个相邻的ORF)进行了基因克隆与表达分析。将073R克隆后构建原核表达质粒pET-32a-073R,并用IPTG进行诱导表达,073R融合蛋白经纯化后,进行免疫小鼠制备抗体;通过Western blot检测经噬藻体感染宿主细胞后073R的表达时序,结果显示在宿主细胞裂解之初,即PaV-LD感染48h以后073R开始表达,表明073R是一个晚期基因;同时073R推导的氨基酸序列与34株噬藻(菌)体及2株藻病毒(感染真核藻的病毒)的主要衣壳蛋白的氨基酸序列进行序列比对,显示073R与无尾的藻病毒衣壳蛋白亲缘关系更近。PCR扩增内肽酶和穿孔素基因123L-124L,并构建质粒pOP123L-124L,将其转入模式藻集胞藻PCC6803细胞中,质粒pOP123L-124L与藻集胞藻PCC6803基因组发生重组,形成重组藻;测定了重组藻与野生藻的生长速率,并绘制生长曲线;制备超薄切片,进一步比较和观察重组藻与野生藻的超微结构的变化。结果显示重组藻与野生藻存在生长速率与超微形态的显著差异。
文摘The paper proposes a new tool to measure the risk in financial market:PaV,which means the hap pening probability with the given loss magnitude,and utilizes Copula function to obtain its computing algorithm.Two cases are illustrated for the promising applications of PaV.
文摘According to the published nucleotide sequences,CP gene of barley yellow dwarf virus PAV(BYDV-PAV) was synthesized by reverse transcription polymerase chain reaction(RT-PCR).The reporter gene GFP was put to the downstream of whole CP gene sequence of BYDV-PAV after double enzyme digestion,PCR identification and sequencing.The green fluorescence protein expression system of coat protein of BYDV-PAV was successfully constructed and expressed in Escherichia coli BL21(DE3)plysS.The expression product was confirmed by SDS-PAGE,Western blot analysis and fluorescence microscope.The fusion gene CP-GFP was expressed in the range of 15-22℃,but could not be expressed at 23-37℃.The results provided a base for studying on BYDV-PAV movement in aphid further.
基金supported by the National Natural Science Fund Project of China(NSFC)(No.:51278173)the Natural Science Fund Project of Jiangsu Provincial Communications Department(No.:SBK201120606)
文摘For the most coastal areas where the air is very humid,study on the effect of humidity on the performance of asphalt has its practical significance.However,limited research has been done to investigate the effect of humidity on rheological properties of asphalt.In this study,asphalt binders were aged in the pressure aging vessel(PAV)under different conditions of moisture and aging time.Then Dynamic Shear Rheometer(DSR)and Bending Beam Rheometer(BBR)measurements were conducted to obtain the parameters relating to the complex modulus,phase angle,failure temperature,and creep stiffness.It was found that the low temperature performance decreased as evidenced by the results of the creep stiffness.While there were no significant differences among conditioned binders based on complex modulus G*and phase angleδ,it was found that theδvalue increased when the humidity increased from 0% to 80% ,and then theδvalue decreased when the humidity increased to 100% .In addition,the results of the failure temperature indicated that the humidity of 80% would be a critical point for the high temperature performance of the asphalt binders.
