Biofilm is a community of bacteria, less susceptible to traditions treatments. Although photodynamic therapy （PDT） is a very effective way to microorganism inactivation, in biofilm it is not as efficient as it is in...Biofilm is a community of bacteria, less susceptible to traditions treatments. Although photodynamic therapy （PDT） is a very effective way to microorganism inactivation, in biofilm it is not as efficient as it is in planktonic bacteria cultures. The increment of an element to increase the effectiveness of PDT was our aim. Therefore, this in vitro study evaluates the susceptibility ofa biofilm formed by Streptococcus mutans on metallic surface of orthodontic accessories under the application of PDT with a surfactant. Samples obtained from blades of orthodontic bands （NiCr）, where used as adhesion surface for the biofilm. They were treated with 1 mg/ml of curcumin, with 0.1% of sodium dodecyl sulfate and exposed to 30 J/cm^2 of light （455 nm）. Eight experimental groups were studied, including the positive and negative controls. The results show that the group with PDT and surfactant had a significant decrease （p 〈 0.001） in viability. In this case, the reduction observed was of 5.6 log10 （CFU/ml） in comparison to the control group. We have shown that, even though the biofilm is very tough and complex structure, we are able to promote almost the complete inactivation ofS. mutans in systems similar to an orthodontic treated patient＇s mouth.展开更多
目的建立气相色谱-串联质谱法(gas chromatography tandem mass spectrometry,GC-MS/MS)测定茶粉中9,10蒽醌残留的检测方法。方法样品经过丙酮-正己烷(1:4,V:V)提取,弗罗里硅土SIPE小柱净化,GC-MS/MS选择离子监测模式(selective reactio...目的建立气相色谱-串联质谱法(gas chromatography tandem mass spectrometry,GC-MS/MS)测定茶粉中9,10蒽醌残留的检测方法。方法样品经过丙酮-正己烷(1:4,V:V)提取,弗罗里硅土SIPE小柱净化,GC-MS/MS选择离子监测模式(selective reaction monitoring,SRM)进行测定,内标法定量。结果在0.02~0.2 mg/kg加标水平下,9,10蒽醌的回收率为91.2%~119.7%,相对标准偏差(relative standard deviations,RSD)在2.14%-6.18%,定量限(limit of quantitation,LOQ)为0.02 mg/kg。结论该方法快速简便、检出限低、灵敏度高、抗干扰性强、节省有机溶剂,适用于速溶茶粉中9,10蒽醌检测。展开更多
文摘Biofilm is a community of bacteria, less susceptible to traditions treatments. Although photodynamic therapy （PDT） is a very effective way to microorganism inactivation, in biofilm it is not as efficient as it is in planktonic bacteria cultures. The increment of an element to increase the effectiveness of PDT was our aim. Therefore, this in vitro study evaluates the susceptibility ofa biofilm formed by Streptococcus mutans on metallic surface of orthodontic accessories under the application of PDT with a surfactant. Samples obtained from blades of orthodontic bands （NiCr）, where used as adhesion surface for the biofilm. They were treated with 1 mg/ml of curcumin, with 0.1% of sodium dodecyl sulfate and exposed to 30 J/cm^2 of light （455 nm）. Eight experimental groups were studied, including the positive and negative controls. The results show that the group with PDT and surfactant had a significant decrease （p 〈 0.001） in viability. In this case, the reduction observed was of 5.6 log10 （CFU/ml） in comparison to the control group. We have shown that, even though the biofilm is very tough and complex structure, we are able to promote almost the complete inactivation ofS. mutans in systems similar to an orthodontic treated patient＇s mouth.
文摘目的建立气相色谱-串联质谱法(gas chromatography tandem mass spectrometry,GC-MS/MS)测定茶粉中9,10蒽醌残留的检测方法。方法样品经过丙酮-正己烷(1:4,V:V)提取,弗罗里硅土SIPE小柱净化,GC-MS/MS选择离子监测模式(selective reaction monitoring,SRM)进行测定,内标法定量。结果在0.02~0.2 mg/kg加标水平下,9,10蒽醌的回收率为91.2%~119.7%,相对标准偏差(relative standard deviations,RSD)在2.14%-6.18%,定量限(limit of quantitation,LOQ)为0.02 mg/kg。结论该方法快速简便、检出限低、灵敏度高、抗干扰性强、节省有机溶剂,适用于速溶茶粉中9,10蒽醌检测。
