Corrigendum to“Reactive oxygen species in plasma against E.coli cells survival rate”

Recently, we found some errors in Fig. 3 of the article Chin. Phys. B 24 085201 (2015). Upon a thorough examination of the raw data materials, we confirm that the image error did not impact any of the findings and conclusions of the paper. Based on this, we have made corrections to the original article.

Reactive oxygen species in plasma against E.coli cells survival rate

In this paper, we report on the contrastive analysis of inactivation efficiency of E. coli cells in solution with different disinfection methods. Compared with the hydrogen peroxide solution and the ozone gas, the atmospheric-pressure He plasma can completely kill the E. coli cells in the shortest time. The inactivation efficiency of E. coli cells in solution can be well described by using the chemical reaction rate model. X-ray photoelectron spectroscopy(XPS) analysis shows that the C–O or C=O content of the inactivated E. coli cell surface by plasma is predominantly increased, indicating the quantity of oxygen-containing species in plasma is more than those of two other methods, and then the C–C or C–H bonds can be broken, leading to the etching of organic compounds. Analysis also indicates that plasma-generated species can play a crucial role in the inactivation process by their direct reactions or the decompositions of reactive species, such as ozone into OH radicals in water, then reacting with E. coli cells.

Effect of rotating liquid samples on dynamic propagation and aqueous activation of a helium plasma jet

This paper aims to explore the effects of a rotating plasma-activated liquid on the dynamic propagation and biomedical application of a helium plasma jet.The spatial distribution of reactive species and the associated physico-chemical reactions are altered by the rotating liquid,which shows a significant weakening in the axial propagation of the plasma bullet and a strengthening in its radial expansion at the liquid surface.The phenomenon is prompted by the nonzero rotational velocity of the liquid and is regulated by airflow,target distance and liquid permittivity.The concentrations of aqueous reactive species,especially OH and O~-,and the inactivation effectiveness on cancer cells are weakened,indicating that a rotating liquid is not conducive to water treatment of the plasma jet although the treatment area of the plasma jet increases dynamically.This finding is of significance for the plasma–liquid interaction and the biomedical-related applications of plasma jets.

水降膜DBD等离子体去除水中磺胺甲恶唑的效能及机理

水降膜介质阻挡放电装置可以在气相高效生成反应活性物质,且大的气–液反应界面有利于反应活性物质的气–液传质,高效降解液相污染物。为此研究了单极性和双极性脉冲电源供电时水降膜装置的放电特性及磺胺甲恶唑(sulfamethoxazole,SMX)的降解效率,研究发现双极性脉冲供电时,水降膜装置放电强度及SMX降解率更高。同时,本文探究了双极性脉冲电压和频率、SMX初始质量浓度、pH值、液体流速和电导率对SMX降解的影响,分析了SMX的降解机理。结果表明:放电功率随放电电压和脉冲频率升高而增大,SMX降解率随之升高,当放电电压较低(24 kV)时,电压升高能提高SMX降解的能量效率,但提升放电频率会导致SMX降解能量效率的下降;液体循环流量和电导率对SMX的降解影响不大;放电功率为5 W,放电处理质量浓度为20 mg/L的200 mL溶液30 min,SMX降解率达到了80.2%,能量效率达到1.28 g/(kW·h);由于过臭氧化和SMX分子的质子化效应,碱性条件下SMX的降解率远高于酸性条件下的降解率。

Ar/H_2O等离子射流作用下生理盐水中H_2O_2的生成

低温常压等离子体产生的丰富的化学活性物种(活性氧和氮基团)在生物医学应用(如伤口消毒和愈合)上有着很高的需求,尤其是活性氧基团(如O(3P)、O(5P)、OH*、O2-、1O2、O、O3和H2O2)有着很强的杀菌能力。为此,采用了一种针-环介质阻挡放电(DBD)结构的Ar/H2O等离子体射流作用于生理盐水中生成H2O2,并对水蒸气体积分数、等离子体处理时间及等离子体处理后储存时间对生理盐水中H2O2浓度的影响进行了相应的研究。研究结果表明:在相同处理时间的情况下,生理盐水中H2O2浓度随着水蒸气体积分数的增大而出现先增后减的情况,而H2O2生成率和能量利用率则受水蒸气体积分数影响不大;在相同水蒸气体积分数的情况下,较长的等离子体处理时间将会导致较高的H2O2浓度、生成率和能量利用率;等离子体处理后的生理盐水中的H2O2在40 min时间内可以相对稳定地存在,显示了H2O2在等离子体药学上应用的可能性。