scholarly journals Development, characterization and application of an improved online reactive oxygen species analyzer based on MARGA

2022 ◽  
Author(s):  
Jiyan Wu ◽  
Chi Yang ◽  
Chunyan Zhang ◽  
Fang Cao ◽  
Aiping Wu ◽  
...  

Abstract. Excessive reactive oxygen species (ROS) in the human body is an important factor leading to diseases. Therefore, research on the content of reactive oxygen species in atmospheric particles is necessary. In order to more conveniently and accurately detect the content of reactive oxygen in atmospheric particles hour by hour. Here, to modify the instrument, it is added a DTT experimental module that is protected from light and filled with nitrogen at the end, based on the Monitor for AeRosols and Gases in ambient Air (MARGA). The experimental study found that the detection limit of the modified instrument is 0.024 nmol min−1. And the accuracy of the online instrument is determined by comparing the online and offline levels of the samples, which yielded good consistency (slope 0.97, R2 = 0.95). It shows that the performance of the instrument is indeed optimized, the instrument is stable, and the characterization of ROS is accurate. Meanwhile, reactive oxygen and inorganic ions in atmospheric particles are quantified using the online technique in the northern suburbs of Nanjing. It is found that the content of ROS during the day is higher than that at night, especially after it rains, ROS peaks appear in the two time periods of 08:00–10:00 and 16:00–18:00. In addition, examination of the online ROS and water-soluble ions (SO42−, NO3−, NH4+, Na+, Ca2+, K+), BC and polluting gases (SO2, CO, O3, NO, NOx) measurements revealed that photo-oxidation and secondary formation processes could be important sources of aerosol ROS. This method breakthrough enables the quantitative assessment of atmospheric particulate matter ROS at the diurnal scale, providing an effective tool to study sources and environmental impacts of ROS.

Environments ◽  
2019 ◽  
Vol 6 (4) ◽  
pp. 42 ◽  
Author(s):  
Kai Zhang ◽  
Dongyang Nie ◽  
Mindong Chen ◽  
Yun Wu ◽  
Xinlei Ge ◽  
...  

PM2.5 pollution is of great concern in China due to its adverse health effects. Many diseases have been proven to be associated with PM2.5 components, but the effects of chemical characteristics of PM2.5 on toxicological properties, especially in different human organs, are poorly understood. In this study, two seasonal PM2.5 samples (summer and winter) were collected in Nanjing, and their chemical compositions (heavy metals, water-soluble ions, organic carbon (OC), and elemental carbon (EC)) were analyzed. Human lung epithelial carcinoma cells (A549), human hepatocellular liver carcinoma cells (HepG2), and human neuroblastoma cells (Sh-Sy5y) were employed to evaluate the toxicological properties of the collected PM2.5. The results showed that the average mass concentrations of PM2.5 were lower in summer (51.3 ± 21.4 μg/m3) than those in winter (62.1 ± 21.5 μg/m3). However, the mass fractions of heavy metals, OC, and EC exhibited an opposite seasonal difference. Among all tested fractions, water-soluble ions were the major compositions of particles in both summer and winter, especially the secondary ions (SO42−, NO3− and NH4+). Besides, the ratio of OC/EC in PM2.5 was greater than two, indicating serious secondary pollution in this area. The NO3–/SO42− ratio (< 1) suggested that fixed sources made important contributions. The toxicological results showed that PM2.5 in the summer and winter significantly inhibited cell viability (p < 0.01) and induced intracellular reactive oxygen species (ROS) production (p < 0.01). Moreover, the viability inhibition in A549, Sh-Sy5y, and HepG2 cells was more prominent in summer, especially at high PM2.5 (400 μg/mL) (p < 0.05), and the induction of reactive oxygen species (ROS) in A549 and Sh-Sy5y cells was also more evident in summer. Such seasonal differences might be related to the variations of PM2.5 components.


2015 ◽  
Vol 198 ◽  
pp. 86-96 ◽  
Author(s):  
Nirmal Kumar Gali ◽  
Fenhuan Yang ◽  
Sabrina Yanan Jiang ◽  
Ka Lok Chan ◽  
Li Sun ◽  
...  

Atmosphere ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 847
Author(s):  
Hao Xiao ◽  
Hua-Yun Xiao ◽  
Zhong-Yi Zhang ◽  
Neng-Jian Zheng ◽  
Qin-kai Li ◽  
...  

Sulfate, nitrate and ammonium (SNA) are the dominant components of water-soluble ions (WSIs) in PM2.5, which are of great significance for understanding the sources and transformation mechanisms of PM2.5. In this study, daily PM2.5 samples were collected from September 2017 to August 2018 within the Guiyang urban area and the concentrations of the major WSIs in the PM2.5 samples were characterized. The results showed that the average concentration of SNA (SO42−, NO3−, NH4+) was 15.01 ± 9.35 μg m−3, accounting for 81.05% (48.71–93.76%) of the total WSIs and 45.33% (14.25–82.43%) of the PM2.5 and their possible chemical composition in PM2.5 was (NH4)2SO4 and NH4NO3. The highest SOR (sulfur oxidation ratio) was found in summer, which was mainly due to the higher temperature and O3 concentrations, while the lowest NOR (nitrogen oxidation ratio) found in summer may ascribe to the volatilization of nitrates being accelerated at higher temperature. Furthermore, the nitrate formation was more obvious in NH4+-rich environments so reducing NH3 emissions could effectively control the formation of nitrate. The results of the trajectory cluster analysis suggested that air pollutants can be easily enriched over short air mass trajectories from local emission sources, affecting the chemical composition of PM2.5.


2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Linping Hu ◽  
Yawen Zhang ◽  
Weimin Miao ◽  
Tao Cheng

Hematopoietic stem cells (HSCs) are characterized by self-renewal and multilineage differentiation potentials. Although they play a central role in hematopoietic homeostasis and bone marrow (BM) transplantation, they are affected by multiple environmental factors in the BM. Here, we review the effects of reactive oxygen species (ROS) and Nrf2 on HSC function and BM transplantation. HSCs reside in the hypoxic microenvironment of BM, and ROS play an important role in HSPC regulation. Recently, an extraphysiologic oxygen shock/stress phenomenon was identified in human cord blood HSCs collected under ambient air conditions. Moreover, Nrf2 has been recently recognized as a master transcriptional factor that regulates multiple antioxidant enzymes. Since several years, the role of Nrf2 in hematopoiesis has been extensively studied, which has functional similarities of cellular oxygen sensor hypoxia-inducible factor-1 as transcriptional factors. Increasing evidence has revealed that abnormally elevated ROS production due to factors such as genetic defects, aging, and ionizing radiation unexceptionally resulted in lethal impairment of HSC function and hematopoiesis. Both experimental and clinical studies have identified elevated ROS levels as a major culprit of ineffective BM transplantation. Lastly, we discuss the possibility of using small molecule antioxidants, such as N-acetyl cysteine, resveratrol, and curcumin, to augment HSC function and improve the therapeutic efficacy of BM transplantation. Further research on the function of ROS levels and improving the efficacy of BM transplantation may have a great potential for broad clinical applications of HSCs.


Author(s):  
Ekaterina Kovel ◽  
Anna Sachkova ◽  
Natalia Vnukova ◽  
Grigoriy Churilov ◽  
Elena Knyazeva ◽  
...  

Fullerenols are nanosized water-soluble polyhydroxylated derivatives of fullerenes, specific allotropic form of carbon, bioactive compounds and perspective pharmaceutical agents. We studied biological effects of a series of fullerenols. Antioxidant activity and toxicity of the fullerenols were compared using bioluminescence assays (cellular and enzymatic); a content of Reactive Oxygen Species in fullerenol solutions was determined using chemiluminescence luminol method. Two groups of fullerenols with different number of hydroxyl substituents were under investigation: (I) С60Оy(OH)x, С60,70Оy(OH)x, where х+у=24&ndash;28 and (II) С60,70Оy(OH)x, Fe0,5С60Оy(OH)x, where х+у=40&ndash;42. Toxicity of the fullerenols was evaluated using effective concentrations ЕС50. Fullerenol&rsquo; antioxidant activity was investigated in model solutions of organic toxicant of oxidative type, 1,4-benzoquinone. Detoxification coefficients were calculated to analyze and compare the antioxidant activity. Higher toxicity and lower antioxidant activity were demonstrated in the solutions of fullerenols with higher number of the oxygen substituents (х+у=40&ndash;42). The differences were concerned with fullerenol&rsquo; ability to disturb Reactive Oxygen Species balance in aqueous solutions. Toxic effect of the prospective endohedral metal-fullerenol with gadolinium atom involved, Gd@C82Oy(OH)x, where х+у=40&ndash;42, was evaluated and explained by a high number of oxygen groups


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