Cold atmospheric plasma shows a satisfactory ability to inactivate bacterial biofilms that are difficult to remove using conventional methods in some cases. However, the researches on the inactivation mechanism are no...Cold atmospheric plasma shows a satisfactory ability to inactivate bacterial biofilms that are difficult to remove using conventional methods in some cases. However, the researches on the inactivation mechanism are not quite sufficient. Poly-β-1–6-N-acetylglucosamine(PNAG),which is one of the important components in some biofilms, was used as the research subject,and the related mechanism of action triggered by different concentrations of the OH in plasma was studied using reactive molecular dynamics simulations. The results showed that OH radicals could not only trigger the hydrogen abstraction reaction leading to cleavage of the PNAG molecular structure, but undergo an OH addition reaction with PNAG molecules. New reaction pathways appeared in the simulations as the OH concentration increased, but the reaction efficiency first increased and then decreased. The simulation study in this paper could, to some extent, help elucidate the microscopic mechanism of the interaction between OH radicals in plasma and bacterial biofilms at the atomic level.展开更多
The World Health Organization(WHO)defines health as“a state of complete physical,mental and social well-being and not merely the absence of disease or infirmity”(WHO,2017),and mental health is defined as not only th...The World Health Organization(WHO)defines health as“a state of complete physical,mental and social well-being and not merely the absence of disease or infirmity”(WHO,2017),and mental health is defined as not only the absence of mental illness,but also the presence of psychological well-being.An expanding body of evidence highlights the relationship between nature(such as urban greenspace)and health(Li et al.,2019;Flaxman et al.,2020).展开更多
We report for the first time, to the best of our knowledge, regenerated polymer optical fiber Bragg gratings(RPOFBGs) in ZEONEX-based polymer optical fibers(POFs). The regeneration temperature can be adjusted using a ...We report for the first time, to the best of our knowledge, regenerated polymer optical fiber Bragg gratings(RPOFBGs) in ZEONEX-based polymer optical fibers(POFs). The regeneration temperature can be adjusted using a heat treatment process on the POF before FBG inscription, enabling a scalable improvement of the thermal stability of the RPOFBGs. Thermal sustainability of the RPOFBGs at high temperature conditions was investigated for their prolonged use in diverse environments. Furthermore, these RPOFBGs can withstand strain levels up to 2.8% while maintaining a good linearity, even at temperature of 110℃. The RPOFBGs are capable of short-term operation at elevated temperatures of up to 132℃, which is the standard temperature for steam sterilization with at least a 4 min exposure period. The distinction in the morphologies of the two grades of ZEONEX(E48R and 480R, ZEON Corp.) used to fabricate the optical fiber together with the characteristics of UV irradiated and regenerated gratings is explained using micro-Raman spectroscopy. Collectively, these findings provide new heights for long-term operation of POF Bragg gratings(POFBGs) at elevated temperature environments and would be applicable to a wide range of disciplines.展开更多
基金supported by National Natural Science Foundation of China(Grant No.11675095)the Fundamental Research Funds of Shandong University(Grant No.2017JC017)。
文摘Cold atmospheric plasma shows a satisfactory ability to inactivate bacterial biofilms that are difficult to remove using conventional methods in some cases. However, the researches on the inactivation mechanism are not quite sufficient. Poly-β-1–6-N-acetylglucosamine(PNAG),which is one of the important components in some biofilms, was used as the research subject,and the related mechanism of action triggered by different concentrations of the OH in plasma was studied using reactive molecular dynamics simulations. The results showed that OH radicals could not only trigger the hydrogen abstraction reaction leading to cleavage of the PNAG molecular structure, but undergo an OH addition reaction with PNAG molecules. New reaction pathways appeared in the simulations as the OH concentration increased, but the reaction efficiency first increased and then decreased. The simulation study in this paper could, to some extent, help elucidate the microscopic mechanism of the interaction between OH radicals in plasma and bacterial biofilms at the atomic level.
基金National Natural Science Foundation of China(No.82001996)Fundamental Research Funds for the Central Universities of China.
文摘The World Health Organization(WHO)defines health as“a state of complete physical,mental and social well-being and not merely the absence of disease or infirmity”(WHO,2017),and mental health is defined as not only the absence of mental illness,but also the presence of psychological well-being.An expanding body of evidence highlights the relationship between nature(such as urban greenspace)and health(Li et al.,2019;Flaxman et al.,2020).
基金RGC General Research Fund(15210019)Department of Science and Technology of Guangdong Province(P0034432).
文摘We report for the first time, to the best of our knowledge, regenerated polymer optical fiber Bragg gratings(RPOFBGs) in ZEONEX-based polymer optical fibers(POFs). The regeneration temperature can be adjusted using a heat treatment process on the POF before FBG inscription, enabling a scalable improvement of the thermal stability of the RPOFBGs. Thermal sustainability of the RPOFBGs at high temperature conditions was investigated for their prolonged use in diverse environments. Furthermore, these RPOFBGs can withstand strain levels up to 2.8% while maintaining a good linearity, even at temperature of 110℃. The RPOFBGs are capable of short-term operation at elevated temperatures of up to 132℃, which is the standard temperature for steam sterilization with at least a 4 min exposure period. The distinction in the morphologies of the two grades of ZEONEX(E48R and 480R, ZEON Corp.) used to fabricate the optical fiber together with the characteristics of UV irradiated and regenerated gratings is explained using micro-Raman spectroscopy. Collectively, these findings provide new heights for long-term operation of POF Bragg gratings(POFBGs) at elevated temperature environments and would be applicable to a wide range of disciplines.
