The red phosphor materials CaS∶Cu+,Eu 2+ were firstly synthesized in a microwave field, and characterized by XRD、SEM、fluorescent spectroscopy. The experimental results of XRD and SEM show that the phosphors of CaS...The red phosphor materials CaS∶Cu+,Eu 2+ were firstly synthesized in a microwave field, and characterized by XRD、SEM、fluorescent spectroscopy. The experimental results of XRD and SEM show that the phosphors of CaS∶Cu+,Eu 2+ possess a spherical crystallite structure, in the submicrometer(250～500 nm) size range. Compared to the conventional high temperature solid state reaction this new synthetic technique exhibits interesting features, such as rapid reactions without other protective atmosphere,phosphors with high purity, smaller particles,and higher efficient luminescence.展开更多
A new chemically mutagenic mutant of Synechococcus PCC7942 named high-CO2 re-quiring mutant, which could grow at 4% CO2 but could not grow at air levels of CO2, was isolated. Com-parative studies on some physiological...A new chemically mutagenic mutant of Synechococcus PCC7942 named high-CO2 re-quiring mutant, which could grow at 4% CO2 but could not grow at air levels of CO2, was isolated. Com-parative studies on some physiological aspects of the mutant and high-cO2 growing cells (growing at 4%CO2 ) were conducted. The result showed that the mutant had lower growing rate, about 1/40th photosyn-thetic affinity to inorganic carbon, 25% lower carbonic anhydrase (CA) activity, lower quenching rate ofchlorophyll fluoresence, and about 1/2 alkalinization rate of the medium. The CA activity responses ofthe two types of cells to different concentrations of CO2 were determined. Upon the addition of inorganiccarbon (Ci), the rate of active Ci uptake described by the rate of chlorophyll fluorescence quenching ofthe mutant was obviously lower compared with that of the high-CO2 growing cells; the size of the internalinorganic carbon pool size determined by the extent of fluorescence quenching Of the mutant was alsosmaller.展开更多
Recently, fluorescence technique becomes very useful. It can allow for addressing a fundamental problem of cellular mechanism besides characterizing the species inside the cell to facilitate the diagnostic and prognos...Recently, fluorescence technique becomes very useful. It can allow for addressing a fundamental problem of cellular mechanism besides characterizing the species inside the cell to facilitate the diagnostic and prognostic value. Manipulation with fluorescent dyes provides many possibilities for their use as tags, probes, and sensors. These types can be intrinsic or extrinsic to the cell. They can become not only silent observers, but also participants, modulators or disruptors of specific activities outline the biological functions can be successfully studied quantitatively and qualitatively with fluorescence techniques.展开更多
用Fura-2/AM技术直接观察前胡丙素(Pra-C)对培养大鼠心室肌细胞内游离钙的影响。结果显示Pra-C浓度为0.1～1.0μmol·L^(-1)可明显抑制CaCl_2,高K^+和Bay K 8644引起[Ca^(2+)]i增加,并且有剂量—效应关系,对ouabain引起的[Ca^(2+)]...用Fura-2/AM技术直接观察前胡丙素(Pra-C)对培养大鼠心室肌细胞内游离钙的影响。结果显示Pra-C浓度为0.1～1.0μmol·L^(-1)可明显抑制CaCl_2,高K^+和Bay K 8644引起[Ca^(2+)]i增加,并且有剂量—效应关系,对ouabain引起的[Ca^(2+)]i增加无明显作用。结果提示Pra-C降低心肌细胞[Ca^(2+)]i的作用与抑制电压依赖性钙通道有关。展开更多
文摘The red phosphor materials CaS∶Cu+,Eu 2+ were firstly synthesized in a microwave field, and characterized by XRD、SEM、fluorescent spectroscopy. The experimental results of XRD and SEM show that the phosphors of CaS∶Cu+,Eu 2+ possess a spherical crystallite structure, in the submicrometer(250～500 nm) size range. Compared to the conventional high temperature solid state reaction this new synthetic technique exhibits interesting features, such as rapid reactions without other protective atmosphere,phosphors with high purity, smaller particles,and higher efficient luminescence.
文摘A new chemically mutagenic mutant of Synechococcus PCC7942 named high-CO2 re-quiring mutant, which could grow at 4% CO2 but could not grow at air levels of CO2, was isolated. Com-parative studies on some physiological aspects of the mutant and high-cO2 growing cells (growing at 4%CO2 ) were conducted. The result showed that the mutant had lower growing rate, about 1/40th photosyn-thetic affinity to inorganic carbon, 25% lower carbonic anhydrase (CA) activity, lower quenching rate ofchlorophyll fluoresence, and about 1/2 alkalinization rate of the medium. The CA activity responses ofthe two types of cells to different concentrations of CO2 were determined. Upon the addition of inorganiccarbon (Ci), the rate of active Ci uptake described by the rate of chlorophyll fluorescence quenching ofthe mutant was obviously lower compared with that of the high-CO2 growing cells; the size of the internalinorganic carbon pool size determined by the extent of fluorescence quenching Of the mutant was alsosmaller.
文摘Recently, fluorescence technique becomes very useful. It can allow for addressing a fundamental problem of cellular mechanism besides characterizing the species inside the cell to facilitate the diagnostic and prognostic value. Manipulation with fluorescent dyes provides many possibilities for their use as tags, probes, and sensors. These types can be intrinsic or extrinsic to the cell. They can become not only silent observers, but also participants, modulators or disruptors of specific activities outline the biological functions can be successfully studied quantitatively and qualitatively with fluorescence techniques.
文摘用Fura-2/AM技术直接观察前胡丙素(Pra-C)对培养大鼠心室肌细胞内游离钙的影响。结果显示Pra-C浓度为0.1～1.0μmol·L^(-1)可明显抑制CaCl_2,高K^+和Bay K 8644引起[Ca^(2+)]i增加,并且有剂量—效应关系,对ouabain引起的[Ca^(2+)]i增加无明显作用。结果提示Pra-C降低心肌细胞[Ca^(2+)]i的作用与抑制电压依赖性钙通道有关。
