Résumé
The effect of CdS quantum dots (QDs) on the electrochemiluminescence (ECL) signal of Ru(bpy)32+ was studied. It was found that CdS QDs could enhance the anodic ECL of Ru(bpy)32+ by 4 times. The sensitization mechanism was discussed and the influence factors including concentrations of Ru (bpy)32+ and CdS QDs, pH of solution and scan rate on ECL intensity were investigated. On the basis of quenching effect of catechol on the ECL signal of CdS QDs-Ru(bpy)32+,a system for sensitive determination of catechol was established with a detection limit of 5.5 nmol/L (S/N=3). This method was applied to the detection of catechol in tea sample with satisfactory results.
Résumé
<p><b>OBJECTIVE</b>To investigate the effects of extremely low frequency electromagnetic field (ELF-EMF) on human osteosarcoma cells and its mechanisms.</p><p><b>METHODS</b>Human osteosarcoma MG-63 cells were exposed to 50 Hz,1 mT ELF-EMF for 1, 2 and 3 h in vitro, with or without pretreatment by reactive oxygen species (ROS) inhibitor N acetylcysteine (NAC) or p38MAPK inhibitor SB203580. The proliferation of MG-63 cells was determined by MTT method; the apoptosis rate and ROS level in MG-63 cells were detected by flow cytometry. The expression of p38MAPK in MG-63 cells was determined by Western blotting.</p><p><b>RESULTS</b>ELF-EMF decreased the viability of MG-63 cells, inhibited cell growth, induced cell apoptosis and increased the level of ROS significantly. The apoptosis rate declined significantly after treatment with ROS inhibitor NAC or p38MAPK inhibitor SB203580. After exposure to ELF-EMF, p38MAPK in MG-63 cells was activated, and the phosphorylation level was also inhibited after treatment with NAC.</p><p><b>CONCLUSION</b>ELF-EMF can induce the apoptosis of MG-63 cells. Increased ROS and p38MAPK activation may be involved in the mechanism.</p>
Sujets)
Humains , Acétylcystéine , Apoptose , Lignée cellulaire tumorale , Prolifération cellulaire , Champs électromagnétiques , Imidazoles , Ostéosarcome , Anatomopathologie , Stress oxydatif , Phosphorylation , Pyridines , Espèces réactives de l'oxygène , Métabolisme , p38 Mitogen-Activated Protein Kinases , MétabolismeRésumé
blossam.This can be used as reference for cultivating and application of Lonicara Japonica.