14H, 18R and 24R long-period stacking ordered （LPSO） structures were observed in the as-cast Mg-3Cu-1Mn-2Zn-1Y damping alloy using transmission electron microscopy （TEM）. These LPSO structures contained Mg, Y, Cu ...14H, 18R and 24R long-period stacking ordered （LPSO） structures were observed in the as-cast Mg-3Cu-1Mn-2Zn-1Y damping alloy using transmission electron microscopy （TEM）. These LPSO structures contained Mg, Y, Cu and Zn and thus they were quaternary phases. Sharp diffraction pattern of the 24R structure was obtained and the angle between and g10024R was measured to be 5.03°. During high resolution TEM observations, lattice fringes with two characteristic spacings were observed within the 24R structure. Based on the experimental results, 6H, 7H and three 8H are suggested as the building blocks of 18R, 14H and 24R structures, respectively. The 24R unit cell can be interpreted as the stacking of 8H building blocks in the same shear direction with a shear angle of about 5.03°. The imperfect 24R structures are in order or disorder arrangements of principal 8H and minor 6H blocks. This double-block structure model is also applicable to other reported defects in LPSO structures.展开更多
AIM： To investigate the effect of lithium on proliferation of esophageal cancer （EC） cells and its preliminary mechanisms. METHODS： Eca-109 cells were treated with lithium chloride, a highly selective inhibitor of...AIM： To investigate the effect of lithium on proliferation of esophageal cancer （EC） cells and its preliminary mechanisms. METHODS： Eca-109 cells were treated with lithium chloride, a highly selective inhibitor of glycogen synthase kinase 31） （GSK-31））, at different concentrations （2-30 mmol/L） and time points （0, 2, 4, 6 and 24 h）. Cell proliferative ability was evaluated by 3-（4,5-Dimethylthiazol-2-yl）-2, 5-diphenyltetrazolium bromide （MTT） assay, and Cell cycle distribution was examined by flow cytometry. Expressions of p-GSK-3β, β-catenin, cyclin B1, cdc2 and cyclin D1 protein were detected by Western blotting, and the subcellular localization of β-catenin was determined by immunofluorescence. The mRNA level of of cyclin B1 was detected by reverse transcription polymerase chain reaction （RT-PCR）. RESULTS： Lithium could inhibit the proliferation of Eca-109 cells. Lithium at a concentration of 20 mmol/L lithium for 24 h produced obvious changes in the distribution of cell cycle, and increased the number of cells in G2/M phase （P 〈 0.05 vs control group）. Western blotting showed that lithium inhibited GSK-β） by Ser-9 phosphorylation and stabilized free β-catenin in the cytoplasm. Immunofluorescence further confirmed that free β-catenin actively translocated to the nucleus. Horeover, lithium slightly elevated cyclin D1 protein expression, whereas lowered the cyclin B1 expression after 24 h lithium exposure and no obvious change was observed for cdc2 protein. CONCLUSION： Lithium can inhibit the proliferation of human esophageal cancer cell line Eca-109 by inducing a G2/H cell cycle arrest, which is mainly mediated through the inhibition of lithium-sensitive molecule, GSK-3β, and reduction of cyclin B1 expression.展开更多
基金Project (2009CB623704) supported by the National Basic Research Program of ChinaProject (50971076) supported by the National Natural Science Foundation of China
文摘14H, 18R and 24R long-period stacking ordered （LPSO） structures were observed in the as-cast Mg-3Cu-1Mn-2Zn-1Y damping alloy using transmission electron microscopy （TEM）. These LPSO structures contained Mg, Y, Cu and Zn and thus they were quaternary phases. Sharp diffraction pattern of the 24R structure was obtained and the angle between and g10024R was measured to be 5.03°. During high resolution TEM observations, lattice fringes with two characteristic spacings were observed within the 24R structure. Based on the experimental results, 6H, 7H and three 8H are suggested as the building blocks of 18R, 14H and 24R structures, respectively. The 24R unit cell can be interpreted as the stacking of 8H building blocks in the same shear direction with a shear angle of about 5.03°. The imperfect 24R structures are in order or disorder arrangements of principal 8H and minor 6H blocks. This double-block structure model is also applicable to other reported defects in LPSO structures.
基金The Innovation Project of Central South University, No. 2340-76208
文摘AIM： To investigate the effect of lithium on proliferation of esophageal cancer （EC） cells and its preliminary mechanisms. METHODS： Eca-109 cells were treated with lithium chloride, a highly selective inhibitor of glycogen synthase kinase 31） （GSK-31））, at different concentrations （2-30 mmol/L） and time points （0, 2, 4, 6 and 24 h）. Cell proliferative ability was evaluated by 3-（4,5-Dimethylthiazol-2-yl）-2, 5-diphenyltetrazolium bromide （MTT） assay, and Cell cycle distribution was examined by flow cytometry. Expressions of p-GSK-3β, β-catenin, cyclin B1, cdc2 and cyclin D1 protein were detected by Western blotting, and the subcellular localization of β-catenin was determined by immunofluorescence. The mRNA level of of cyclin B1 was detected by reverse transcription polymerase chain reaction （RT-PCR）. RESULTS： Lithium could inhibit the proliferation of Eca-109 cells. Lithium at a concentration of 20 mmol/L lithium for 24 h produced obvious changes in the distribution of cell cycle, and increased the number of cells in G2/M phase （P 〈 0.05 vs control group）. Western blotting showed that lithium inhibited GSK-β） by Ser-9 phosphorylation and stabilized free β-catenin in the cytoplasm. Immunofluorescence further confirmed that free β-catenin actively translocated to the nucleus. Horeover, lithium slightly elevated cyclin D1 protein expression, whereas lowered the cyclin B1 expression after 24 h lithium exposure and no obvious change was observed for cdc2 protein. CONCLUSION： Lithium can inhibit the proliferation of human esophageal cancer cell line Eca-109 by inducing a G2/H cell cycle arrest, which is mainly mediated through the inhibition of lithium-sensitive molecule, GSK-3β, and reduction of cyclin B1 expression.
