目的在体外矿化体系中探讨磷灰石结合肽NH2-CLPLWYPSC-COOH(CLP)和NH2-CYENLRSTC-COOH(CYE)介导的钙磷微粒的自组装。方法固相法合成环状肽CYE和CLP。构建碱性磷酸酶(alkalinephosphatase,AP)控释的溶液仿生矿化体系,将添加剂CYE、CLP...目的在体外矿化体系中探讨磷灰石结合肽NH2-CLPLWYPSC-COOH(CLP)和NH2-CYENLRSTC-COOH(CYE)介导的钙磷微粒的自组装。方法固相法合成环状肽CYE和CLP。构建碱性磷酸酶(alkalinephosphatase,AP)控释的溶液仿生矿化体系,将添加剂CYE、CLP和牛血清白蛋白(BSA)以100μg/mL浓度预溶于体系中,以不含添加剂的体系为阴性对照。监测体系90min内每5min A820nm值的变化情况。扫描电子显微镜(scanning electron microscopy,SEM)和透射电子显微镜(transmission electron microscopy,TEM)观察沉积物形貌及组装模式。结果 BSA促进矿化反应的发生,CLP和CYE则表现为对矿化的抑制。环状肽(特别是CYE)作用于矿化前体并使其形成特殊的片层状结构。陈化28h和96h后,CLP和CYE组中的片状钙磷微晶组装形成多孔的纳米颗粒,而阴性对照和BSA组中的矿化球则长至微米级。TEM和选区电子衍射(selected area electron diffraction,SAED)结果证实,添加剂可诱导不同的微晶自组装模式,并延迟非晶相向磷灰石相的转变。结论磷灰石结合肽CLP、CYE抑制磷酸钙成核,延迟晶体变相,其中CYE可诱导片状微晶自组装成特殊的纳米螺旋管状结构。展开更多
In order to conquer the defect in low precision and small range for measuring optic axial angle based on conoscopic interference method, interference fringe method is proposed. It is not the distance deviating from me...In order to conquer the defect in low precision and small range for measuring optic axial angle based on conoscopic interference method, interference fringe method is proposed. It is not the distance deviating from melatope but fringe numbers to decide optic axial angle. Fringe numbers are divided into integer portion and decimal fraction portion, the decimal fraction portion is calculated by non-linear interpolation method and integer portion is determined by the relative placement of interference fringes in the principal section. Extremum arithmetic of digit image is proposed and can be used to determine the interference fringes conveniently and precisely. After different niobate crystals were measured, the result shows that measurement range of optic axial angle is increased efficiently and measurement error is reduced to 0.1°.展开更多
By employing the dielectric continuum model and Loudon＇s uniaxial crystal model, the interface optical （IO） phonon modes in a freestanding quasi-one-dimensional （Q1D） wurtzite rectangular quantum wire are derived...By employing the dielectric continuum model and Loudon＇s uniaxial crystal model, the interface optical （IO） phonon modes in a freestanding quasi-one-dimensional （Q1D） wurtzite rectangular quantum wire are derived and analyzed. Numerical calculation on a freestanding wurtzite GaN quantum wire is performed. The resulte reveal that the dispersion frequencies of IO modes sensitively depend on the geometric structures of the Q1D wurtzite rectangular quantum wires, the free wave-number kz in z-direction and the dielectric constant of the nonpolar matrix. The degenerating behavior of the IO modes in Q1D wurtzite rectangular quantum wire has been clearly observed in the case of small wave-number kz and Iarge ratio of length to width of the rectangular crossing profile. The limited frequency behaviors of IO modes have been analyzed deeply, and detailed comparisons with those in wurtzite planar quantum wells and cylindrical quantum wires are also done. The present theories can be looked on as a generalization of that in isotropic rectangular quantum wires, and it can naturally reduce to the case of Q1D isotropic quantum wires once the anisotropy of the wurtzite material is ignored.展开更多
文摘目的在体外矿化体系中探讨磷灰石结合肽NH2-CLPLWYPSC-COOH(CLP)和NH2-CYENLRSTC-COOH(CYE)介导的钙磷微粒的自组装。方法固相法合成环状肽CYE和CLP。构建碱性磷酸酶(alkalinephosphatase,AP)控释的溶液仿生矿化体系,将添加剂CYE、CLP和牛血清白蛋白(BSA)以100μg/mL浓度预溶于体系中,以不含添加剂的体系为阴性对照。监测体系90min内每5min A820nm值的变化情况。扫描电子显微镜(scanning electron microscopy,SEM)和透射电子显微镜(transmission electron microscopy,TEM)观察沉积物形貌及组装模式。结果 BSA促进矿化反应的发生,CLP和CYE则表现为对矿化的抑制。环状肽(特别是CYE)作用于矿化前体并使其形成特殊的片层状结构。陈化28h和96h后,CLP和CYE组中的片状钙磷微晶组装形成多孔的纳米颗粒,而阴性对照和BSA组中的矿化球则长至微米级。TEM和选区电子衍射(selected area electron diffraction,SAED)结果证实,添加剂可诱导不同的微晶自组装模式,并延迟非晶相向磷灰石相的转变。结论磷灰石结合肽CLP、CYE抑制磷酸钙成核,延迟晶体变相,其中CYE可诱导片状微晶自组装成特殊的纳米螺旋管状结构。
文摘In order to conquer the defect in low precision and small range for measuring optic axial angle based on conoscopic interference method, interference fringe method is proposed. It is not the distance deviating from melatope but fringe numbers to decide optic axial angle. Fringe numbers are divided into integer portion and decimal fraction portion, the decimal fraction portion is calculated by non-linear interpolation method and integer portion is determined by the relative placement of interference fringes in the principal section. Extremum arithmetic of digit image is proposed and can be used to determine the interference fringes conveniently and precisely. After different niobate crystals were measured, the result shows that measurement range of optic axial angle is increased efficiently and measurement error is reduced to 0.1°.
基金The project supported by the Science and Technology Project of Advanced Academy of Guangzhou City under Grant No. 2060. The author acknowledges the detailed and valuable discussions with Prof. J.J. Shi.
文摘By employing the dielectric continuum model and Loudon＇s uniaxial crystal model, the interface optical （IO） phonon modes in a freestanding quasi-one-dimensional （Q1D） wurtzite rectangular quantum wire are derived and analyzed. Numerical calculation on a freestanding wurtzite GaN quantum wire is performed. The resulte reveal that the dispersion frequencies of IO modes sensitively depend on the geometric structures of the Q1D wurtzite rectangular quantum wires, the free wave-number kz in z-direction and the dielectric constant of the nonpolar matrix. The degenerating behavior of the IO modes in Q1D wurtzite rectangular quantum wire has been clearly observed in the case of small wave-number kz and Iarge ratio of length to width of the rectangular crossing profile. The limited frequency behaviors of IO modes have been analyzed deeply, and detailed comparisons with those in wurtzite planar quantum wells and cylindrical quantum wires are also done. The present theories can be looked on as a generalization of that in isotropic rectangular quantum wires, and it can naturally reduce to the case of Q1D isotropic quantum wires once the anisotropy of the wurtzite material is ignored.
