采用RT-PCR技术扩增禽呼肠孤病毒(ARV)S1133毒株和广西分离株R 1的2σ基因。将2σ基因克隆至PGEX-4T-1载体上,测序结果表明,插入的片段为2σ目的基因。切下目的基因2σ重组到含有谷胱甘肽(G ST)的融合蛋白质原核表达载体PGEX-4T-1,获得...采用RT-PCR技术扩增禽呼肠孤病毒(ARV)S1133毒株和广西分离株R 1的2σ基因。将2σ基因克隆至PGEX-4T-1载体上,测序结果表明,插入的片段为2σ目的基因。切下目的基因2σ重组到含有谷胱甘肽(G ST)的融合蛋白质原核表达载体PGEX-4T-1,获得重组质粒。经PCR、酶切以及序列分析鉴定,表达2σ基因插入的位置、大小和读码框架均正确,表明成功构建了融合表达载体PGEX-S1133-2σ和PGEX-R 1-2σ。构建好的重组质粒,在大肠杆菌JM 109α中经1 mm o l/L IPTG诱导得到了表达。融合蛋白G ST-2σ和G ST R 1-2σ的相对分子质量为65 100,以包涵体形式存在。W estern-b lot分析表明,融合蛋白能够与ARV阳性血清发生特异性反应,表明该重组蛋白具有良好的反应原性。展开更多
The perovskite samples La1-x（Sr1-yKy）xMnO3 （y = 0.0, 0.2, 04, 0.6, 0.8） were prepared by the solid-state reaction method with comparatively low sintering tem- perature and with comparatively short sintering time, ...The perovskite samples La1-x（Sr1-yKy）xMnO3 （y = 0.0, 0.2, 04, 0.6, 0.8） were prepared by the solid-state reaction method with comparatively low sintering tem- perature and with comparatively short sintering time, and the electric transport property and temperature stability of MR of this system were studied. The p-T curves show the abnormal phenomenon that with the increase of K doping amount, resistivity increases, and the insulator-metal transition temperature decreases, which is because the influence of the occupation disorder degree of A-site ions σ2 on the electric transport property of perovskite manga- nites is larger than that of the radius of A-site ions （rA）. In the temperature range below 225 K, MR increases contin- uously with the decrease of temperature, which is the characteristic of low-field magnetoresistance; in the com- paratively wide temperature range near 250 K, the MR- T curves of all the samples are comparatively fiat, and the value of MR almost does not change with temperature, which shows the temperature stability of magnetoresis- tance, and can be explained by the competition between the low-field magnetoresistance induced by spin-dependent tunneling of surface phase and the intrinsic magnetoresis- tance of grain phase. The magnetoresistance value of the sample with y = 0.8 keeps at （7.92 ±0.36） % in the very wide temperature range of 225-275 K, and this is a goodreference for the preparation of this kind of sample with practical application value in the future.展开更多
Let G be a connected graph of order n. The rainbow connection number rc（G） of G was introduced by Chartrand et al. Chandran et al. used the minimum degree of G and obtained an upper bound that rc（G） 〈_ 3n/（ δ...Let G be a connected graph of order n. The rainbow connection number rc（G） of G was introduced by Chartrand et al. Chandran et al. used the minimum degree of G and obtained an upper bound that rc（G） 〈_ 3n/（ δ＋ 1） - 3, which is tight up to additive factors. In this paper, we use the minimum degree-sum a2 6n of G to obtain a better bound rc（G） _〈 - 8, especially when is small （constant） but a2 is large （linear in n）.展开更多
We have discovered and synthesized a series of indole-based derivatives as novel sigma-2(σ_(2))receptor ligands.Two ligands with high σ_(2) receptor affinity and subtype selectivity were then radiolabeled with F-18 ...We have discovered and synthesized a series of indole-based derivatives as novel sigma-2(σ_(2))receptor ligands.Two ligands with high σ_(2) receptor affinity and subtype selectivity were then radiolabeled with F-18 in good radiochemical yields and purities,and evaluated in rodents.In biodistribution studies in male ICR mice,radioligand[18F]9,or 1-(4-(5,6-dimethoxyisoindolin-2-yl)butyl)-4-(2-[18F]fluoroethoxy)-1H-indole,was found to display high brain uptake and high brain-to-blood ratio.Pretreatment of animals with the selective σ_(2) receptor ligand CM398 led to significant reductions in both brain uptake(29%-54%)and brain-to-blood ratio(60%-88%)of the radioligand in a dose-dependent manner,indicating high and saturable specific binding of[18F]9 to σ_(2) receptors in the brain.Further,ex vivo autoradiography in male ICR mice demonstrated regionally heterogeneous specific binding of[18F]9 in the brain that is consistent with the distribution pattern of σ_(2) receptors.Dynamic positron emission tomography imaging confirmed regionally distinct distribution and high levels of specific binding for[18F]9 in the rat brain,along with appropriate tissue kinetics.Taken together,results from our current study indicated the novel radioligand[18F]9 as the first highly specific and promising imaging agent for σ_(2) receptors in the brain.展开更多
文摘采用RT-PCR技术扩增禽呼肠孤病毒(ARV)S1133毒株和广西分离株R 1的2σ基因。将2σ基因克隆至PGEX-4T-1载体上,测序结果表明,插入的片段为2σ目的基因。切下目的基因2σ重组到含有谷胱甘肽(G ST)的融合蛋白质原核表达载体PGEX-4T-1,获得重组质粒。经PCR、酶切以及序列分析鉴定,表达2σ基因插入的位置、大小和读码框架均正确,表明成功构建了融合表达载体PGEX-S1133-2σ和PGEX-R 1-2σ。构建好的重组质粒,在大肠杆菌JM 109α中经1 mm o l/L IPTG诱导得到了表达。融合蛋白G ST-2σ和G ST R 1-2σ的相对分子质量为65 100,以包涵体形式存在。W estern-b lot分析表明,融合蛋白能够与ARV阳性血清发生特异性反应,表明该重组蛋白具有良好的反应原性。
基金financially supported by the National Natural Science Foundation of China (No. 19934003)the Key Program of Natural Science Foundation of Anhui Province (Nos. KJ2011A259 and KJ2013A245)+1 种基金the Program of Professors and Doctors' Research Startup Foundation of Suzhou College (Nos. 2011jb01 and 2011jb02)the Program of Cultivating Base of Anhui Key Laboratory of Spintronics and Nano-materials Research (No. 2012YKF09)
文摘The perovskite samples La1-x（Sr1-yKy）xMnO3 （y = 0.0, 0.2, 04, 0.6, 0.8） were prepared by the solid-state reaction method with comparatively low sintering tem- perature and with comparatively short sintering time, and the electric transport property and temperature stability of MR of this system were studied. The p-T curves show the abnormal phenomenon that with the increase of K doping amount, resistivity increases, and the insulator-metal transition temperature decreases, which is because the influence of the occupation disorder degree of A-site ions σ2 on the electric transport property of perovskite manga- nites is larger than that of the radius of A-site ions （rA）. In the temperature range below 225 K, MR increases contin- uously with the decrease of temperature, which is the characteristic of low-field magnetoresistance; in the com- paratively wide temperature range near 250 K, the MR- T curves of all the samples are comparatively fiat, and the value of MR almost does not change with temperature, which shows the temperature stability of magnetoresis- tance, and can be explained by the competition between the low-field magnetoresistance induced by spin-dependent tunneling of surface phase and the intrinsic magnetoresis- tance of grain phase. The magnetoresistance value of the sample with y = 0.8 keeps at （7.92 ±0.36） % in the very wide temperature range of 225-275 K, and this is a goodreference for the preparation of this kind of sample with practical application value in the future.
基金Supported by the National Natural Science Foundation of China(No.11071130)the Fundamental Research Funds for the Central Universities
文摘Let G be a connected graph of order n. The rainbow connection number rc（G） of G was introduced by Chartrand et al. Chandran et al. used the minimum degree of G and obtained an upper bound that rc（G） 〈_ 3n/（ δ＋ 1） - 3, which is tight up to additive factors. In this paper, we use the minimum degree-sum a2 6n of G to obtain a better bound rc（G） _〈 - 8, especially when is small （constant） but a2 is large （linear in n）.
基金supported by the National Natural Science Foundation of China(No.21876013)Beijing Natural Science Foundation(7212203,China)。
文摘We have discovered and synthesized a series of indole-based derivatives as novel sigma-2(σ_(2))receptor ligands.Two ligands with high σ_(2) receptor affinity and subtype selectivity were then radiolabeled with F-18 in good radiochemical yields and purities,and evaluated in rodents.In biodistribution studies in male ICR mice,radioligand[18F]9,or 1-(4-(5,6-dimethoxyisoindolin-2-yl)butyl)-4-(2-[18F]fluoroethoxy)-1H-indole,was found to display high brain uptake and high brain-to-blood ratio.Pretreatment of animals with the selective σ_(2) receptor ligand CM398 led to significant reductions in both brain uptake(29%-54%)and brain-to-blood ratio(60%-88%)of the radioligand in a dose-dependent manner,indicating high and saturable specific binding of[18F]9 to σ_(2) receptors in the brain.Further,ex vivo autoradiography in male ICR mice demonstrated regionally heterogeneous specific binding of[18F]9 in the brain that is consistent with the distribution pattern of σ_(2) receptors.Dynamic positron emission tomography imaging confirmed regionally distinct distribution and high levels of specific binding for[18F]9 in the rat brain,along with appropriate tissue kinetics.Taken together,results from our current study indicated the novel radioligand[18F]9 as the first highly specific and promising imaging agent for σ_(2) receptors in the brain.
