The ongoing SARS-CoV-2 outbreak has rapidly increased the desire to manage bioaerosol exposures in indoor settings. Studies using chlorine dioxide gas (ClO<sub>2</sub>) at low concentrations have shown thi...The ongoing SARS-CoV-2 outbreak has rapidly increased the desire to manage bioaerosol exposures in indoor settings. Studies using chlorine dioxide gas (ClO<sub>2</sub>) at low concentrations have shown this intervention to be an effective mitigation strategy against viral, bacterial, and fungal elements in ambient air. There is an array of available products for generating ClO<sub>2</sub> gas however most involve the use of expensive or sophisticated technology that makes their applicability limited to specialized consumers. The purpose of this study was to determine the virucidal efficacy of three pragmatic and affordable, ClO<sub>2</sub> generating products using an aerosolized MS2 surrogate in a sealed chamber room under five different scenarios. The products tested included: Ultrashock—a ClO<sub>2</sub> releasing pod (30 ppmv), Filter Media—a ClO<sub>2</sub> impregnated zeolite media made to fit into an air blower housing (<0.01 ppmv) and Flow Stick—a smaller ClO<sub>2</sub> impregnated media filled air reactor tube (<0.01 ppmv). Testing scenarios included product deployment post MS2 bioaerosol introduction (Ultrashock and Filter Media), during MS2 bioaerosol introduction (Filter Media and Flow Stick) and prior to MS2 bioaerosol introduction (Filter Media). MS2 surface samples were collected using sterile petri-dishes and MS2 and ClO<sub>2</sub> air samples were collected from sampling ports on the outer chamber wall at 0, 90 and 180 minutes. The Ultrashock and Filter Media with air flow in the rapid sweep scenario showed the greatest reduction in air MS2 (T<sub>180</sub> = 99.992% and T<sub>180</sub> = 99.996% respectively) compared to the control (T<sub>180 </sub>= 99.6%). When compared to the control results, the filter media with air flow engaged prior to the introduction of MS2 yielded reductions of 99.87% and 99.93% in air and on surfaces respectively at T<sub>0</sub>, demonstrating the protective effect residual ClO2 has against air and surface contamination. These product formats have potential uses as remedial and preventative interventions against viral constituents in air and should undergo further evaluation to determine efficacy and human health risk.展开更多
The SET mechanism between chlorine dioxide （ClO2） and phenol was studied by using ab initio method at 4-31G* level. Geometries of the reactants, intermediate and products of the reaction were optimized and the singl...The SET mechanism between chlorine dioxide （ClO2） and phenol was studied by using ab initio method at 4-31G* level. Geometries of the reactants, intermediate and products of the reaction were optimized and the single point energy calculations of the species were performed. The relative structure data of the reactants, intermediate and products are given.The SET mechanism between ClO2and phenol was confirmed by ab initio calculations. The reaction is exothermic about 200 88 kJ/mol.展开更多
Chlorine dioxide(ClO2),an alternative disinfectant to chlorine,has a superior ability to inactivate microorganisms,in which protein damage has been considered as the main inactivation mechanism.However,the reactivity ...Chlorine dioxide(ClO2),an alternative disinfectant to chlorine,has a superior ability to inactivate microorganisms,in which protein damage has been considered as the main inactivation mechanism.However,the reactivity of ClO2 with amino acid residues in oligopeptides and proteins remains poorly investigated.In this research,we studied the reaction rate constants of ClO2 with tryptophan residues in five heptapeptides and four proteins using stopped-flow or competition kinetic method.Each heptapeptide and protein contain only one tryptophan residue and the reactivity of tryptophan residue with ClO2 was lower than that of free tryptophan(3.88×10^4(mol/L)^-1 sec^-1 at pH 7.0).The neighboring amino acid residues affected the reaction rates through promoting inter-peptide aggregation,changing electron density,shifting pKa values or inducing electron transfer via redox reactions.A single amino acid residue difference in oligopeptides can make the reaction rate constants differ by over 60%(e.g.3.01×10^4(mol/L)^-1 sec^-1 for DDDWNDD and 1.85×10^4(mol/L)^-1 sec^-1 for DDDWDDD at pH 7.0(D:aspartic acid,W:tryptophan,N:asparagine)).The reaction rates of tryptophan-containing oligopeptides were also highly pH-dependent with higher reactivity for deprotonated tryptophan than the neutral specie.Tryptophan residues in proteins spanned a 4-fold range reactivity toward ClO2(i.e.0.84×10^4(mol/L)^-1 sec^-1 for ribonuclease T1 and 3.21×10^4(mol/L)^-1 sec^-1 for melittin at pH 7.0)with accessibility to the oxidant as the determinating factor.The local environment surrounding the tryptophan residue in proteins can also accelerate the reaction rates by increasing the electron density of the indole ring of tryptophan or inhibit the reaction rates by inducing electron transfer reactions.The results are of significance in advancing understanding of ClO2 oxidative reactions with proteins and microbial inactivation mechanisms.展开更多
Avian influenza remains a threat to human wellbeing.Hypochlorite derivatives are commonly used as disinfectants to prevent the spread of the disease.The World Health Organization(WHO)has listed chlorine dioxide(ClO_(2...Avian influenza remains a threat to human wellbeing.Hypochlorite derivatives are commonly used as disinfectants to prevent the spread of the disease.The World Health Organization(WHO)has listed chlorine dioxide(ClO_(2))as an A1‐level,safe,and efficient disinfectant.In this study,we tested the efficacy of ClO_(2),in aqueous solution and gas forms,against avian influenza A(H7N9)virus.The virus suspension was mixed with ClO_(2) aqueous solutions of various concentrations and for various time intervals.Aliquots of the mixture were then serially diluted,and the 50%tissue culture infective dose(TCID50)was measured with a hemagglutination test on MDCK cells.ClO_(2) gas produced from generators was introduced in a chamber containing the virus suspension in a Petri dish.The infective activity of the surviving virus was measured by the hemagglutination test.An aqueous solution of ClO_(2) at 126μg/mL for 15 s was effective given that no surviving virus was detected with the hemagglutination test.ClO_(2) gas at>5μL/L sustained for 1 h inactivated the virus effectively,while at 2.5μL/L for 1 h,it only partially inactivated the virus.ClO_(2) as gas or aqueous solution at a certain concentration is effective in inactivating the H7N9 virus,and can be applied for the decontamination and disinfection of environments.展开更多
为研制一种适用于酸性条件下的固体H_(2)S抑制剂,在室温(20℃)酸性条件下以水为溶剂、以二乙醇(DEA)胺和二氧化氯(ClO_(2))作为抑制剂对H_(2)S抑制率进行研究,利用硬脂酸、氢氧化钠、羟丙基甲基纤维素、聚乙二醇和七水硫酸锌使抑制剂成...为研制一种适用于酸性条件下的固体H_(2)S抑制剂,在室温(20℃)酸性条件下以水为溶剂、以二乙醇(DEA)胺和二氧化氯(ClO_(2))作为抑制剂对H_(2)S抑制率进行研究,利用硬脂酸、氢氧化钠、羟丙基甲基纤维素、聚乙二醇和七水硫酸锌使抑制剂成型。经实验20 mL 15%的二乙醇胺和0.57%的二氧化氯溶液抑制效果最佳,达到67.14%。不同温度条件下抑制剂对硫化氢的抑制率随温度上升而降低,基本稳定在66%~67%之间。不同温度条件下抑制剂与混合酸液体系(以镇北油田在用酸液体系为例)配伍性良好,抑制率随温度上升而降低,基本稳定在65%~67%之间。实验结果表明:成型抑制剂以抑制剂与七水硫酸锌质量比为1∶9时的抑制剂效果最好,达到80.57%。该新型H_(2)S抑制剂在不同酸性条件、温度下都拥有较好的抑制效果,固态成型后为解决油田液态抑制剂加注困难、加注浪费问题提供了参考方案。展开更多
In acidic medium, malonic used as masking agent, let the mixed aqueous of chlorine dioxide and chlorine react with Fe2+, then have the residual Fe2+ coloured with 1.10phenanthroline solution. The authors...In acidic medium, malonic used as masking agent, let the mixed aqueous of chlorine dioxide and chlorine react with Fe2+, then have the residual Fe2+ coloured with 1.10phenanthroline solution. The authors can quantify the content of chlorine dioxide and chlorine in the water by detecting the difference of absorbtivity of the coloured solution when it is no masking agent and it is added masking agent. The method is simple, innocuity, specific, quick, accurate and sensitive. The mini detect limitation are:Chlorine: 7.66×10-3mg/L,dioxide Chlorine: 2.91×10-3mg/L.R is 0.9997,CV is 2.55%.展开更多
文摘The ongoing SARS-CoV-2 outbreak has rapidly increased the desire to manage bioaerosol exposures in indoor settings. Studies using chlorine dioxide gas (ClO<sub>2</sub>) at low concentrations have shown this intervention to be an effective mitigation strategy against viral, bacterial, and fungal elements in ambient air. There is an array of available products for generating ClO<sub>2</sub> gas however most involve the use of expensive or sophisticated technology that makes their applicability limited to specialized consumers. The purpose of this study was to determine the virucidal efficacy of three pragmatic and affordable, ClO<sub>2</sub> generating products using an aerosolized MS2 surrogate in a sealed chamber room under five different scenarios. The products tested included: Ultrashock—a ClO<sub>2</sub> releasing pod (30 ppmv), Filter Media—a ClO<sub>2</sub> impregnated zeolite media made to fit into an air blower housing (<0.01 ppmv) and Flow Stick—a smaller ClO<sub>2</sub> impregnated media filled air reactor tube (<0.01 ppmv). Testing scenarios included product deployment post MS2 bioaerosol introduction (Ultrashock and Filter Media), during MS2 bioaerosol introduction (Filter Media and Flow Stick) and prior to MS2 bioaerosol introduction (Filter Media). MS2 surface samples were collected using sterile petri-dishes and MS2 and ClO<sub>2</sub> air samples were collected from sampling ports on the outer chamber wall at 0, 90 and 180 minutes. The Ultrashock and Filter Media with air flow in the rapid sweep scenario showed the greatest reduction in air MS2 (T<sub>180</sub> = 99.992% and T<sub>180</sub> = 99.996% respectively) compared to the control (T<sub>180 </sub>= 99.6%). When compared to the control results, the filter media with air flow engaged prior to the introduction of MS2 yielded reductions of 99.87% and 99.93% in air and on surfaces respectively at T<sub>0</sub>, demonstrating the protective effect residual ClO2 has against air and surface contamination. These product formats have potential uses as remedial and preventative interventions against viral constituents in air and should undergo further evaluation to determine efficacy and human health risk.
文摘The SET mechanism between chlorine dioxide （ClO2） and phenol was studied by using ab initio method at 4-31G* level. Geometries of the reactants, intermediate and products of the reaction were optimized and the single point energy calculations of the species were performed. The relative structure data of the reactants, intermediate and products are given.The SET mechanism between ClO2and phenol was confirmed by ab initio calculations. The reaction is exothermic about 200 88 kJ/mol.
基金supported by the National Key Research and Development Program of China(No.2017YFE0133200)the National Natural Science Foundation of China(Nos.21622706 and 21876210)the Guangdong Provincial Science and Technology Planning Project(No.2019A050503006)。
文摘Chlorine dioxide(ClO2),an alternative disinfectant to chlorine,has a superior ability to inactivate microorganisms,in which protein damage has been considered as the main inactivation mechanism.However,the reactivity of ClO2 with amino acid residues in oligopeptides and proteins remains poorly investigated.In this research,we studied the reaction rate constants of ClO2 with tryptophan residues in five heptapeptides and four proteins using stopped-flow or competition kinetic method.Each heptapeptide and protein contain only one tryptophan residue and the reactivity of tryptophan residue with ClO2 was lower than that of free tryptophan(3.88×10^4(mol/L)^-1 sec^-1 at pH 7.0).The neighboring amino acid residues affected the reaction rates through promoting inter-peptide aggregation,changing electron density,shifting pKa values or inducing electron transfer via redox reactions.A single amino acid residue difference in oligopeptides can make the reaction rate constants differ by over 60%(e.g.3.01×10^4(mol/L)^-1 sec^-1 for DDDWNDD and 1.85×10^4(mol/L)^-1 sec^-1 for DDDWDDD at pH 7.0(D:aspartic acid,W:tryptophan,N:asparagine)).The reaction rates of tryptophan-containing oligopeptides were also highly pH-dependent with higher reactivity for deprotonated tryptophan than the neutral specie.Tryptophan residues in proteins spanned a 4-fold range reactivity toward ClO2(i.e.0.84×10^4(mol/L)^-1 sec^-1 for ribonuclease T1 and 3.21×10^4(mol/L)^-1 sec^-1 for melittin at pH 7.0)with accessibility to the oxidant as the determinating factor.The local environment surrounding the tryptophan residue in proteins can also accelerate the reaction rates by increasing the electron density of the indole ring of tryptophan or inhibit the reaction rates by inducing electron transfer reactions.The results are of significance in advancing understanding of ClO2 oxidative reactions with proteins and microbial inactivation mechanisms.
基金The study was supported by the National Science and Technology Major Project(NSTMP)for the Prevention and Treatment of Infectious Diseases(2018ZX10734401,2018ZX10301208)NSTMP for the Development of Novel Drugs(2019ZX09721001)+1 种基金Health policy research project of Shanghai Health Commission(2021HP05)This work was supported by Taiko Pharmaceutical Co.,Ltd.
文摘Avian influenza remains a threat to human wellbeing.Hypochlorite derivatives are commonly used as disinfectants to prevent the spread of the disease.The World Health Organization(WHO)has listed chlorine dioxide(ClO_(2))as an A1‐level,safe,and efficient disinfectant.In this study,we tested the efficacy of ClO_(2),in aqueous solution and gas forms,against avian influenza A(H7N9)virus.The virus suspension was mixed with ClO_(2) aqueous solutions of various concentrations and for various time intervals.Aliquots of the mixture were then serially diluted,and the 50%tissue culture infective dose(TCID50)was measured with a hemagglutination test on MDCK cells.ClO_(2) gas produced from generators was introduced in a chamber containing the virus suspension in a Petri dish.The infective activity of the surviving virus was measured by the hemagglutination test.An aqueous solution of ClO_(2) at 126μg/mL for 15 s was effective given that no surviving virus was detected with the hemagglutination test.ClO_(2) gas at>5μL/L sustained for 1 h inactivated the virus effectively,while at 2.5μL/L for 1 h,it only partially inactivated the virus.ClO_(2) as gas or aqueous solution at a certain concentration is effective in inactivating the H7N9 virus,and can be applied for the decontamination and disinfection of environments.
文摘为研制一种适用于酸性条件下的固体H_(2)S抑制剂,在室温(20℃)酸性条件下以水为溶剂、以二乙醇(DEA)胺和二氧化氯(ClO_(2))作为抑制剂对H_(2)S抑制率进行研究,利用硬脂酸、氢氧化钠、羟丙基甲基纤维素、聚乙二醇和七水硫酸锌使抑制剂成型。经实验20 mL 15%的二乙醇胺和0.57%的二氧化氯溶液抑制效果最佳,达到67.14%。不同温度条件下抑制剂对硫化氢的抑制率随温度上升而降低,基本稳定在66%~67%之间。不同温度条件下抑制剂与混合酸液体系(以镇北油田在用酸液体系为例)配伍性良好,抑制率随温度上升而降低,基本稳定在65%~67%之间。实验结果表明:成型抑制剂以抑制剂与七水硫酸锌质量比为1∶9时的抑制剂效果最好,达到80.57%。该新型H_(2)S抑制剂在不同酸性条件、温度下都拥有较好的抑制效果,固态成型后为解决油田液态抑制剂加注困难、加注浪费问题提供了参考方案。
文摘In acidic medium, malonic used as masking agent, let the mixed aqueous of chlorine dioxide and chlorine react with Fe2+, then have the residual Fe2+ coloured with 1.10phenanthroline solution. The authors can quantify the content of chlorine dioxide and chlorine in the water by detecting the difference of absorbtivity of the coloured solution when it is no masking agent and it is added masking agent. The method is simple, innocuity, specific, quick, accurate and sensitive. The mini detect limitation are:Chlorine: 7.66×10-3mg/L,dioxide Chlorine: 2.91×10-3mg/L.R is 0.9997,CV is 2.55%.
