The long afterglow fluorescent material of M1-3xAl2O4:Eu2+ x/Dy3+2x(M2+= Sr2+, Ca2+ and Ba2+) phosphors are successfully synthesized by calcining precursor obtained via co-precipitation method at 1300oC for 4 h with r...The long afterglow fluorescent material of M1-3xAl2O4:Eu2+ x/Dy3+2x(M2+= Sr2+, Ca2+ and Ba2+) phosphors are successfully synthesized by calcining precursor obtained via co-precipitation method at 1300oC for 4 h with reducing atmosphere (20% H2 and 80% N2). The phase evolution, morphology and afterglow fluorescent properties are systematically studied by the various instruments of XRD, FE-SEM, PLE/PL spectroscopy and fluorescence decay analysis. The PL spectra shows that the Sr1-3xAl2O4:Eu2+x/Dy3+ 2x phosphors display vivid green emission at s519 nm (4f65d1!4f7 transition of Eu2+) with monitoring of the maximum excitation wavelength at s334 nm (8S7=2!6IJ transition of Eu2+), among which the optimal concentration of Eu2+ and Dy3+ is 15 at.% and 30 at.%, respectively. The color coordinates and temperature of Sr1-3xAl2O4:Eu2+ x/Dy3+ 2x phosphors are approximately at (s0.27, s0.57) and s6700 K, respectively. On the above basis, the M0:55Al2O4:Eu2+ 0:15/Dy3+ 0:3 (M2+= Ca2+ and Ba2+) phosphors is obtained by the same method. The PL spectra of these phosphors shows the strongest blue emission at s440 nm and cyan emission at s499 nm under s334 nm wavelength excitation, respectively, which are blue shifted comparing to Sr1??3xAl2O4:Eu2+ x/Dy3+ 2x phosphors. The color coordinates and temperatures of M0:55Al2O4:Eu2+ 0:15/Dy3+ 0:3 (M2+= Ca2+ and Ba2+) phosphors are approximately at (s0.18, s0.09), s2000 K and (s0.18, s0.42), s11600 K, respectively. In this work, long afterglow materials of green, blue and cyan aluminates phosphors with excellent properties have been prepared, in order to obtain wide application in the field of night automatic lighting and display.展开更多
In autodigestion assays, endonuclease activity in non apoptotic HL 60 promyelocytic leukemia cell nuclei cleaved the chromatin of the autologous cells to an oligonucleosomal length pattern. Both EGTA and EDTA inhibite...In autodigestion assays, endonuclease activity in non apoptotic HL 60 promyelocytic leukemia cell nuclei cleaved the chromatin of the autologous cells to an oligonucleosomal length pattern. Both EGTA and EDTA inhibited the activation of endonuclease activity in isolated HL 60 cell nuclei. The inhibition by EDTA could be reversed by exogenous Ca 2+ , but not by exogenous Mg 2+ . In Ca 2+ /Mg 2+ free nuclei digestion buffer, addition of Ca 2+ （1\10 mmol/L） induced endonuclease activity in the isolated nuclei, while addition of Mg 2+ had no effect. In the presence of Ca 2+ （0.1 mmol/L）, endonuclease activity was enhanced by exogenous Mg 2+ （0.1\10 mmol/L）. These results suggest that the endonuclease responsible for internucleosomal DNA fragmentation in HL 60 cells during apoptosis is activated by Ca 2+ and further modulated by Mg 2+ in the presence of Ca 2+ .展开更多
基金the National Natural Science Foundation of China (No. 51602126)the National Key Research and Development Plan of China (No. 2016YFB0303505)+1 种基金China and University of Jinan Postdoctoral Science Foundation (No. 2017M622118 and XBH1716)the 111 Project of International Corporation on Advanced Cement-based Materials (D17001).
文摘The long afterglow fluorescent material of M1-3xAl2O4:Eu2+ x/Dy3+2x(M2+= Sr2+, Ca2+ and Ba2+) phosphors are successfully synthesized by calcining precursor obtained via co-precipitation method at 1300oC for 4 h with reducing atmosphere (20% H2 and 80% N2). The phase evolution, morphology and afterglow fluorescent properties are systematically studied by the various instruments of XRD, FE-SEM, PLE/PL spectroscopy and fluorescence decay analysis. The PL spectra shows that the Sr1-3xAl2O4:Eu2+x/Dy3+ 2x phosphors display vivid green emission at s519 nm (4f65d1!4f7 transition of Eu2+) with monitoring of the maximum excitation wavelength at s334 nm (8S7=2!6IJ transition of Eu2+), among which the optimal concentration of Eu2+ and Dy3+ is 15 at.% and 30 at.%, respectively. The color coordinates and temperature of Sr1-3xAl2O4:Eu2+ x/Dy3+ 2x phosphors are approximately at (s0.27, s0.57) and s6700 K, respectively. On the above basis, the M0:55Al2O4:Eu2+ 0:15/Dy3+ 0:3 (M2+= Ca2+ and Ba2+) phosphors is obtained by the same method. The PL spectra of these phosphors shows the strongest blue emission at s440 nm and cyan emission at s499 nm under s334 nm wavelength excitation, respectively, which are blue shifted comparing to Sr1??3xAl2O4:Eu2+ x/Dy3+ 2x phosphors. The color coordinates and temperatures of M0:55Al2O4:Eu2+ 0:15/Dy3+ 0:3 (M2+= Ca2+ and Ba2+) phosphors are approximately at (s0.18, s0.09), s2000 K and (s0.18, s0.42), s11600 K, respectively. In this work, long afterglow materials of green, blue and cyan aluminates phosphors with excellent properties have been prepared, in order to obtain wide application in the field of night automatic lighting and display.
文摘In autodigestion assays, endonuclease activity in non apoptotic HL 60 promyelocytic leukemia cell nuclei cleaved the chromatin of the autologous cells to an oligonucleosomal length pattern. Both EGTA and EDTA inhibited the activation of endonuclease activity in isolated HL 60 cell nuclei. The inhibition by EDTA could be reversed by exogenous Ca 2+ , but not by exogenous Mg 2+ . In Ca 2+ /Mg 2+ free nuclei digestion buffer, addition of Ca 2+ （1\10 mmol/L） induced endonuclease activity in the isolated nuclei, while addition of Mg 2+ had no effect. In the presence of Ca 2+ （0.1 mmol/L）, endonuclease activity was enhanced by exogenous Mg 2+ （0.1\10 mmol/L）. These results suggest that the endonuclease responsible for internucleosomal DNA fragmentation in HL 60 cells during apoptosis is activated by Ca 2+ and further modulated by Mg 2+ in the presence of Ca 2+ .
