In order to investigate the bacteria and fungi aerosol characteristic distribution in HVAC-system and its components at Shaanxi History Museum.Measurements were performed to probe the bacteria and fungi aerosol in HVA...In order to investigate the bacteria and fungi aerosol characteristic distribution in HVAC-system and its components at Shaanxi History Museum.Measurements were performed to probe the bacteria and fungi aerosol in HVAC systems,located at Xi'an city,China.The results showed that there was fungi growth inside the ventilation ducts,fungi contamination was worse than bacteria,and both of them were distributed into occupied space with the air supply ducts.The dominating genera of fungi was found to be Penicillium spp.and Aspergillus spp.,which was respectively 46.1% and 20.7% in settling fungi,and the dominating genera of fungi in dust were Cladosporium spp.and Penicillium spp.,which was 41.8% and 30.1% respectively.It suggests that available measures to improve and control the performance of HVAC-systems such as the maintenance,management and cleaning should be taken to prevent this pollution and to develop strategies to keep this pollution away.展开更多
Study Objective: The purpose of the study is to present independent laboratory testing for a novel technology in air and on surfaces. Since 2020, public health goals have focused on improving indoor air quality. This ...Study Objective: The purpose of the study is to present independent laboratory testing for a novel technology in air and on surfaces. Since 2020, public health goals have focused on improving indoor air quality. This includes protection from airborne pathogens, such as tuberculosis, RSV, SARS-CoV-2, common cold or influenza viruses, measles, and others. Engineering controls are highly effective at reducing hazardous pathogens found in indoor air and from recontamination of surfaces. This occurs from a continuous cycle of settling of small, sustained airborne pathogens, which may become dehumidified, becoming airborne again, carried by room air currents around indoor spaces, then repeating the cycle. Methods: The novel technology utilizes a catalytic process to produce safe levels of hydrogen peroxide gas that are effective in reducing pathogens in the air and on surfaces. Air testing was performed with the MS2 bacteriophage, the test organism for ASHRAE standard 241, and methicillin-Resistant Staphylococcus aureus (MRSA). Surface testing was performed with SARS-COV-2 (Coronavirus COVID-19) and H1N1 (Influenza). Typical ventilation and filtration does not effectively remove disbursed pathogens from the entire facility, due to inconsistent air circulation and surface deposits of pathogens. Results: MS2 was reduced by 99.9%;MRSA was reduced by 99.9%;SARS-CoV-2 was reduced by 99.9%;H1N1 was reduced by 99.9%. Conclusion: This novel catalytic converter reduces a variety of pathogens in the air (99%) and on surfaces (99%), by actively disinfecting with the introduction of gaseous hydrogen peroxide. This active disinfection provides a strong solution for protecting the entire facility and its occupants.展开更多
In this research,an atmospheric-pressure air plasma is used to inactivate the multidrug-resistant Acinetobacter baumannii in liquid.The efficacy of the air plasma on bacterial deactivation and the cytobiological varia...In this research,an atmospheric-pressure air plasma is used to inactivate the multidrug-resistant Acinetobacter baumannii in liquid.The efficacy of the air plasma on bacterial deactivation and the cytobiological variations after the plasma treatment are investigated.According to colony forming units,nearly all the bacteria（6-log） are inactivated after 10 min of air plasma treatment.However,7% of the bacteria enter a viable but non-culturable state detected by the resazurin based assay during the same period of plasma exposure.Meanwhile,86% of the bacteria lose their membrane integrity in the light of SYTO 9/PI staining assay.The morphological changes in the cells are examined by scanning electron microscopy and bacteria with morphological changes are rare after plasma exposure in the liquid.The concentrations of the long-living RS,such as H2O2,NO3^- and O3,in liquid induced by plasma treatment are measured,and they increase with plasma treatment time.The changes of the intracellular ROS may be related to cell death,which may be attributed to oxidative stress and other damage effects induced by RS plasma generated in liquid.The rapid and effective bacteria inactivation may stem from the RS in the liquid generated by plasma and air plasmas may become a valuable therapy in the treatment of infected wounds.展开更多
基金Supported by the National Natural Science Foundation of China(50878177)the Rearch Fund for the Doctoral Program of Higher Education
文摘In order to investigate the bacteria and fungi aerosol characteristic distribution in HVAC-system and its components at Shaanxi History Museum.Measurements were performed to probe the bacteria and fungi aerosol in HVAC systems,located at Xi'an city,China.The results showed that there was fungi growth inside the ventilation ducts,fungi contamination was worse than bacteria,and both of them were distributed into occupied space with the air supply ducts.The dominating genera of fungi was found to be Penicillium spp.and Aspergillus spp.,which was respectively 46.1% and 20.7% in settling fungi,and the dominating genera of fungi in dust were Cladosporium spp.and Penicillium spp.,which was 41.8% and 30.1% respectively.It suggests that available measures to improve and control the performance of HVAC-systems such as the maintenance,management and cleaning should be taken to prevent this pollution and to develop strategies to keep this pollution away.
文摘Study Objective: The purpose of the study is to present independent laboratory testing for a novel technology in air and on surfaces. Since 2020, public health goals have focused on improving indoor air quality. This includes protection from airborne pathogens, such as tuberculosis, RSV, SARS-CoV-2, common cold or influenza viruses, measles, and others. Engineering controls are highly effective at reducing hazardous pathogens found in indoor air and from recontamination of surfaces. This occurs from a continuous cycle of settling of small, sustained airborne pathogens, which may become dehumidified, becoming airborne again, carried by room air currents around indoor spaces, then repeating the cycle. Methods: The novel technology utilizes a catalytic process to produce safe levels of hydrogen peroxide gas that are effective in reducing pathogens in the air and on surfaces. Air testing was performed with the MS2 bacteriophage, the test organism for ASHRAE standard 241, and methicillin-Resistant Staphylococcus aureus (MRSA). Surface testing was performed with SARS-COV-2 (Coronavirus COVID-19) and H1N1 (Influenza). Typical ventilation and filtration does not effectively remove disbursed pathogens from the entire facility, due to inconsistent air circulation and surface deposits of pathogens. Results: MS2 was reduced by 99.9%;MRSA was reduced by 99.9%;SARS-CoV-2 was reduced by 99.9%;H1N1 was reduced by 99.9%. Conclusion: This novel catalytic converter reduces a variety of pathogens in the air (99%) and on surfaces (99%), by actively disinfecting with the introduction of gaseous hydrogen peroxide. This active disinfection provides a strong solution for protecting the entire facility and its occupants.
基金supported by the Spark Program of the second Affiliated Hospital of Anhui Medical University (Grant No.2015hhjh04)National Natural Science Foundation of China under Grant No.51777206+6 种基金Natural Science Foundation of Anhui Province (Grant No.1708085MA13 and No.1708085MB47)Science Foundation of Institute of Plasma Physics,Chinese Academy of Sciences under Grant (No.DSJJ-14-YY02)City University of Hong Kong Applied Research Grant (ARG) (No.9667144)Hong Kong Research Grants Council (RGC) General Research Funds (GRF) (No.City U 11301215)Doctoral Fund of Ministry of Education of China (No.2017M612058)Specialized Research Fund for the Doctoral Program of Hefei University of Technology (No.JZ2016HGBZ0768)Foundation of Anhui Province Key Laboratory of Medical Physics and Technology (Grant No.LMPT2017Y7BP0U1581)
文摘In this research,an atmospheric-pressure air plasma is used to inactivate the multidrug-resistant Acinetobacter baumannii in liquid.The efficacy of the air plasma on bacterial deactivation and the cytobiological variations after the plasma treatment are investigated.According to colony forming units,nearly all the bacteria（6-log） are inactivated after 10 min of air plasma treatment.However,7% of the bacteria enter a viable but non-culturable state detected by the resazurin based assay during the same period of plasma exposure.Meanwhile,86% of the bacteria lose their membrane integrity in the light of SYTO 9/PI staining assay.The morphological changes in the cells are examined by scanning electron microscopy and bacteria with morphological changes are rare after plasma exposure in the liquid.The concentrations of the long-living RS,such as H2O2,NO3^- and O3,in liquid induced by plasma treatment are measured,and they increase with plasma treatment time.The changes of the intracellular ROS may be related to cell death,which may be attributed to oxidative stress and other damage effects induced by RS plasma generated in liquid.The rapid and effective bacteria inactivation may stem from the RS in the liquid generated by plasma and air plasmas may become a valuable therapy in the treatment of infected wounds.
