中文摘要：

研究了介质阻挡放电等离子体针对肺癌A549细胞的灭活机制，探讨从不锈钢管注入到氦等离子体尾流区域的氧气含量对杀灭肺癌细胞A549的影响．利用中性红吸收测试法定性观察了等离子体处理后死亡的细胞和活着的细胞的形态区别，并且定量测定了不同条件下的细胞存活率．在固定功率24w的处理过程中，氦一氧等离子体的灭活效率主要取决于等离子体曝光时间以及氦气中添加氧气的百分含量．实验结果显示最好的处理参数为：处理时间150S，800mL／min的氦气添加3％氧气，保持针距样品的距离为3nlnl．根据氦．氧等离子体发射光谱，可以推断在细胞灭活过程中，氦．氧等离子体中的活性粒子（如羟基和氧自由基）起主要作用．

英文摘要：

An inactivation mechanism of A549 cancer cells is studied by using a dielectric barrier discharge （DBD） plasma needle. The influence of oxygen concentration, which is injected into helium plasma afterglow region through a stainless steel tube, is investigated. The neutral red uptake assay provides a qualitative observation of morphological differences between the dead cells and the viable ceils after plasma treatment and a quantitative estimation of cell viability under different conditions. In the treatment process at a fixed power of 24 W, the inactivation efficiency of helium-oxygen plasma depends mainly on the exposure time and percentage of added oxygen in helium plasma. Experimental results show that the best parameters of the process are 150 s treatment time, 800 mL/min He with 3% Oz addition and separation of needle-to-sample 3 mm. According to the helium-oxygen emission spectra of the plasma jet, it is concluded that the reactive species （for example, OH and O） in the helium-oxygen plasma play a major role in the cell deactivation.