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Resveratrol prevents benzo(a)pyrene-induced disruption of mitochondrial homeostasis via the AMPK signaling pathway in primary cultured neurons 全文
2020
Kang, Run-Run | Sun, Qian | Chen, Kai-Ge | Cao, Qing-Tian | Liu, Chang | Liu, Kuan | Ma, Zhuo | Deng, Yu | Liu, Wei | Xu, Bin
Exposure to benzo(a)pyrene (BaP) has been shown to cause mitochondrial dysfunction and injury to neural cells. Resveratrol (RSV) has been studied as an antioxidant, anti-inflammatory, anti-apoptotic, and anticancer agent and can modulate mitochondrial function in vitro and in vivo. However, the molecular mechanisms underlying RSV’s protection against mitochondrial dysfunction have not been fully elucidated. To investigate whether RSV can effectively prevent BaP-induced mitochondrial dysfunction, we tested the effects of RSV in primary neuronal models. Our results confirmed that neurons exhibited mitochondrial dysfunction and apoptosis in the mitochondrial pathway after BaP-treatment, and that pretreatment with RSV could reduce that dysfunction. Further, our results indicated that RSV pretreatment enhanced mitochondrial biogenesis via the AMPK/PGC-1α pathway and activated mitophagy via the PINK1-Parkin and AMPK/ULK1 pathways, thereby coordinating mitochondrial homeostasis. We also found that RSV could alleviate mitochondrial network fragmentation caused by BaP. This work provided insights into the role of RSV in preventing BaP-induced primary neuronal apoptosis in the mitochondrial pathway, mainly via regulation of mitochondrial biogenesis and mitophagy through AMPK pathway, thus maintaining the integrity of the mitochondrial network.
显示更多 [+] 显示较少 [-]Quantitative assessment of groundwater pollution risk in reclaimed water irrigation areas of northern China 全文
2020
Wu, Wenyong | Liao, Renkuan | Hu, Yaqi | Wang, Hao | Liu, Honglu | Yin, Shiyang
The application of reclaimed water for agricultural irrigation can effectively reduce the use of freshwater resources including groundwater, addressing the increasingly severe challenge of water shortage. However, reclaimed water irrigation will cause potential pollution risks to groundwater, which needs to be further studied to ensure the safety of reclaimed water irrigation. An integrated quantitative assessment system including the modified DRASTIC model was developed to evaluate the pollution risks caused by reclaimed water irrigation and scientific strategies were offered for the development of reclaimed water irrigation in water shortage areas to avoid groundwater pollution. The groundwater intrinsic vulnerability index, the hazards of the characteristic pollutants, and the groundwater values were quantified to obtain the pollution risks distribution map. In the Beijing plain of north China, the low groundwater pollution risk areas were located in the midstream of Chaobai river baisin, Beiyun river basin, and Yongding river basin, accounting for 48.3% of the total study area. These areas in low pollution risk can be considered as safety areas for reclaimed water irrigation. The moderate groundwater pollution risk areas accounting for 46.9% of the total study area were suggested to apply water-saving irrigation measures for preventing groundwater pollution. The reclaimed water irrigation should be prohibited in the high groundwater pollution risk areas, which accounted for 4.8% of the total study area. This study highlights the reasonable strategy for the development of reclaimed water irrigation in water shortage areas and lay a foundation for finding alternative water sources for agricultural irrigation.
显示更多 [+] 显示较少 [-]Microwave-assisted rapid degradation of DDT using nanohybrids of PANI with SnO2 derived from Psidium Guajava extract 全文
2020
Riaz, Ufana | Zia, Jannatun
The present work reports microwave-assisted synthesis of SnO₂ nanoparticles via green route using Psidium Guajava extract. For the enhancement of catalytic activity, nanohybrids of SnO₂ were formulated using different ratios of polyaniline (PANI) via ultrasound-assisted chemical polymerization. Formation of nanohybrids was confirmed via IR and XPS studies. The UV–vis DRS spectra of PANI/SnO₂ revealed significant reduction in the optical band gap upon nanohybrid formation. Microwave-assisted catalytic efficiency of pure SnO₂, PANI, PANI/SnO₂ nanohybrids was investigated using DDT as a model persistent organic pollutant. The degradation efficiency of PANI/SnO₂ was found to increase with the increase in the loading of PANI. Around 87% of DDT degradation was achieved within a very short period of 12 min under microwave irradiation using PANI/SnO₂-50/50 as catalyst. The effect of DDT concentration was explored and the degradation efficiency of PANI/SnO₂-50/50 catalyst was noticed to be as high as 82% in presence of 100 mg/L of DDT. The effect of microwave power on the degradation efficiency revealed 79% degradation using the same nanohybrid when exposed to microwave irradiation for 5 min under 1110 W microwave power. Scavenging studies confirmed the generation of OH, O₂⁻ radicals. The fragments with m/z values as low as 86 and 70 were confirmed by LCMS analysis. Recyclability tests showed that PANI/SnO₂-50/50 nanohybrid exhibited 81% degradation of DDT (500 mg/L) even after the third cycle, which reflected high catalytic efficiency as well as remarkable stability of the catalyst. This green nanohybrid could therefore be effectively utilized for the rapid degradation of persistent organic pollutants.
显示更多 [+] 显示较少 [-]Polycyclic aromatic hydrocarbons (PAHs) leachates from cigarette butts into water 全文
2020
Dobaradaran, Sina | Schmidt, Torsten C. | Lorenzo-Parodi, Nerea | Kaziur-Cegla, Wiebke | Jochmann, Maik A. | Nabipour, Iraj | Lutze, Holger V. | Telgheder, U. (Ursula)
Cigarette butts (CBs) are the most common littered items in the environment and may contain high amounts of polycyclic aromatic hydrocarbons (PAHs) from incomplete tobacco leave burning. The potential relevance of PAHs stemming from CBs for aquatic systems remain unclear since to date there is no systematic study on PAHs leaching from CBs. Therefore, in this study the leaching concentrations of 16 EPA-PAHs (except benzo(ghi)perylene) in 3 different types of water were measured. The concentrations of ΣPAHs leachates from 4 h to 21 days ranged from 3.9 to 5.7, 3.3–5.5, and 3.0–5.0 μg L⁻¹ for deionized, tap, and river waters, respectively. For all contact times, there were no substantial differences of the leachate concentrations of PAHs among different water types. Lighter PAHs had the highest concentrations among the detected PAHs and they were detected in the leachates already after 4 h. Concentrations of indeno(1,2,3-cd)pyrene, and dibenz(a,h)anthracene were below the limit of detection in all water samples at different contact times. At all contact times naphthalene and fluorene had the highest concentrations among the studied PAHs. Tap and river water samples with addition of sodium azide as chemical preservative contained significantly higher concentration of ΣPAHs. Our leaching data showed that leached concentrations of PAHs exceeded the Water Framework Directive (WFD) standards and considering the number of CBs annually littered this may pose a risk to aquatic organisms and potentially also humans.
显示更多 [+] 显示较少 [-]Transformation and removal of imidacloprid mediated by silver ferrite nanoparticle facilitated peroxymonosulfate activation in water: Reaction rates, products, and pathways 全文
2020
Kan, Qihui | Lu, Kun | Dong, Shipeng | Shen, Danlei | Huang, Qingguo | Tong, Yang | Wu, Wei | Gao, Shixiang | Mao, Liang
Imidacloprid (IMI) is one of the most extensively used chlorinated organic pesticides and its widespread occurrence makes it attract increased public concern and scientific interest. Peroxymonosulfate (PMS) activation has been widely studied for the elimination of organic pollutants from water. But few studies are focused on their heterogeneous catalytic performance towards imidacloprid especially with the presence of silver ferrite nanoparticles (nAgFeO₂)-based catalysts. Herein, the catalyst, nAgFeO₂, was prepared via a co-precipitation method, and further applied to activate PMS for the removal of imidacloprid (IMI). Our results demonstrated that the prepared nAgFeO₂ significantly promoted the activation of PMS for removing IMI, and the removal of IMI followed a pseudo first-order kinetics model with the corresponding nAgFeO₂ dosage. Electron paramagnetic resonance (EPR) and quenching tests revealed the singlet oxygen (¹O₂)-mediated nonradical pathway, instead of hydroxyl radical (•OH) or sulfate radical (SO4•−), played the dominant role in the degradation of IMI. Eight products were identified and the degradation pathways of IMI were proposed. It is postulated that the primary site at the C-1 position of IMI was more easily attacked by the •OH yielding (6-chloropyridin-3-yl) methanol). While the site at the amidine nitrogen (2) of IMI was more likely attacked by the ¹O₂, and then reacted with •OH to produce 5-hydroxy imidacloprid. Overall, this study provides insights into the mechanisms of nonradical oxidation processes based on PMS for the elimination of pesticides from water, broadening the application of silver ferrite nanoparticles in wastewater treatment.
显示更多 [+] 显示较少 [-]Using a distributed air sensor network to investigate the spatiotemporal patterns of PM2.5 concentrations 全文
2020
Cao, Rong | Li, Bai | Wang, Zhanyong | Peng, Zhong-Ren | Tao, Shikang | Lou, Shengrong
Spatiotemporal variations in PM₂.₅ are a key factor affecting personal pollution exposure levels in urban areas. However, fixed-site monitoring stations are so sparsely distributed that they hardly capture the dynamic and fine-scale variations in PM₂.₅ in urban areas with complex geographical features and urban forms. Recently, a distributed air sensor network (DASN) was deployed in Dezhou city, China, to monitor fine-scale air pollution information and obtain deep insight into variations in PM₂.₅. Based on the data collected by the DASN, this paper investigated the spatiotemporal patterns of PM₂.₅ using the time-series clustering method. The results demonstrated that there were four stages of PM₂.₅ daily variations, i.e., accumulation, continuous pollution, dispersion, and cleaning. Generally, the stage of dispersion occurred more rapidly than the stage of accumulation, and PM₂.₅ accumulated easily in warm and humid weather with low wind speeds. However, the stage of dispersion was affected mainly by high wind speeds and precipitation. Additionally, the results suggested that four variation stages did not strictly correspond to seasonal divisions. The spatial distributions of PM₂.₅ revealed that the main pollution source was located in a southeastern industrial park, which exhibited a significant impact throughout the four stages. Considering both the temporal and spatial characteristics of PM₂.₅, this study successfully identified pollution hotspots and confirmed the effect of industrial parks. The study demonstrates that the DASN has high prospective applicability for assessing the fine-scale spatial distribution of PM₂.₅, and the time-series clustering method can also assist environmental researchers in further exploring the spatiotemporal characteristics of urban air pollution.
显示更多 [+] 显示较少 [-]Ocean acidification affects biological activities of seaweeds: A case study of Sargassum vulgare from Ischia volcanic CO2 vents 全文
2020
Kumar, Amit | Buia, Maria Cristina | Palumbo, Anna | Mohany, Mohamed | Wadaan, Mohammed A.M. | Hozzein, Wael N. | Beemster, Gerrit T.S. | AbdElgawad, Hamada
We utilized volcanic CO₂ vents at Castello Aragonese off Ischia Island as a natural laboratory to investigate the effect of lowered pH/elevated CO₂ on the bioactivities of extracts from fleshy brown algae Sargassum vulgare C. Agardh. We analysed the carbohydrate levels, antioxidant capacity, antibacterial, antifungal, antiprotozoal, anticancer properties and antimutagenic potential of the algae growing at the acidified site (pH ∼ 6.7) and those of algae growing at the nearby control site Lacco Ameno (pH∼8.1). The results of the present study show that the levels of polysaccharides fucoidan and alginate were higher in the algal population at acidified site. In general, extracts for the algal population from the acidified site showed a higher antioxidant capacity, antilipidperoxidation, antibacterial, antifungal, antiprotozoal, anticancer activities and antimutagenic potential compared to the control population. The increased bioactivity in acidified population could be due to elevated levels of bioactive compounds of algae and/or associated microbial communities. In this snapshot study, we performed bioactivity assays but did not characterize the chemistry and source of presumptive bioactive compounds. Nevertheless, the observed improvement in the medicinal properties of S. vulgare in the acidified oceans provides a promising basis for future marine drug discovery.
显示更多 [+] 显示较少 [-]Quantification of fluoroquinolones in wastewaters by liquid chromatography-tandem mass spectrometry 全文
2020
Maia, Alexandra S. | Paíga, Paula | Delerue-Matos, Cristina | Castro, Paula M.L. | Tiritan, Maria Elizabeth
Antibiotics are the most consumed therapeutic classes worldwide and are released to the environment in their original form as well as potentially active metabolites and/or degradation products. Consequences of the occurrence of these compounds in the environment are primarily related to bacterial resistance development.This work presents a validated analytical method based on solid phase extraction (SPE) using HLB cartridges, followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) for quantification of seven different fluoroquinolone antibiotics, namely ciprofloxacin (CPF), enrofloxacin (ENR), lomefloxacin (LOM), norfloxacin (NOR), ofloxacin (OFL), prulifloxacin (PLF) and moxifloxacin (MOX) and its application to detect the target compounds in influents and effluents of wastewater treatment plants (WWTP). Linearity was established through calibration curves in solvent and matrix match using internal calibration method in the range of 50–1300 ng L⁻¹ and all the fluoroquinolones showed good linear fit (r² ≥ 0.991). Accuracy ranged between 80.3 and 92.9%, precision was comprised between 7.2 and 14.6%, and 10.7 and 18.1% for intra- and inter-batch determinations, respectively. Method detection and quantification limits ranged from 6.7 to 59.0 ng L⁻¹ and 22.3–196.6 ng L⁻¹, respectively.Influents and effluents of fifteen WWTPs of North of Portugal were analyzed. OFL was the fluoroquinolone found at the highest concentration, up to 4587.0 ng L⁻¹ and 987.9 ng L⁻¹, in influent and effluent, respectively. NOR and PLF were not detected.
显示更多 [+] 显示较少 [-]Dissemination of antibiotic resistance genes (ARGs) via integrons in Escherichia coli: A risk to human health 全文
2020
Zhang, Shaqiu | ʻAbbās, Muḥammad | Rehman, Mujeeb Ur | Huang, Yahui | Zhou, Rui | Gong, Siyue | Yang, Hong | Chen, Shuling | Wang, Mingshu | Cheng, Anchun
With the induction of various emerging environmental contaminants such as antibiotic resistance genes (ARGs), environment is considered as a key indicator for the spread of antimicrobial resistance (AMR). As such, the ARGs mediated environmental pollution raises a significant public health concern worldwide. Among various genetic mechanisms that are involved in the dissemination of ARGs, integrons play a vital role in the dissemination of ARGs. Integrons are mobile genetic elements that can capture and spread ARGs among environmental settings via transmissible plasmids and transposons. Most of the ARGs are found in Gram-negative bacteria and are primarily studied for their potential role in antibiotic resistance in clinical settings. As one of the most common microorganisms, Escherichia coli (E. coli) is widely studied as an indicator carrying drug-resistant genes, so this article aims to provide an in-depth study on the spread of ARGs via integrons associated with E. coli outside clinical settings and highlight their potential role as environmental contaminants. It also focuses on multiple but related aspects that do facilitate environmental pollution, i.e. ARGs from animal sources, water treatment plants situated at or near animal farms, agriculture fields, wild birds and animals. We believe that this updated study with summarized text, will facilitate the readers to understand the primary mechanisms as well as a variety of factors involved in the transmission and spread of ARGs among animals, humans, and the environment.
显示更多 [+] 显示较少 [-]Occurrence of organic plastic additives in surface waters of the Rhône River (France) 全文
2020
Schmidt, Natascha | Castro-Jiménez, Javier | Fauvelle, Vincent | Ourgaud, Mélanie | Sempéré, Richard
We present here a comprehensive study (1-year regular sampling) on the occurrence of major families of organic plastic additives in the Rhône River surface waters. Potential sources and contaminant export are also discussed. A total of 22 dissolved phase samples were analyzed for 22 organic additives mainly used in the plastic industry, including organophosphate esters (OPEs), phthalates (PAEs) and bisphenols (BPs). Our results indicate that PAEs were the most abundant class, with concentrations ranging from 97 to 541 ng L⁻¹, followed by OPEs (85–265 ng L⁻¹) and BPs (4–21 ng L⁻¹). Among PAEs, diethylhexyl phthalate (DEHP) was the most abundant compound, whereas TCPP (Tris(1-chloro-2-propyl) phosphate) and TnBP (Tri(n-butyl)phosphate) were the predominant OPEs. Bisphenol S was the only BP detected. 5–54 metric tons year⁻¹ of dissolved organic plastic additives of emerging concern are estimated to be exported to the Gulf of Lion by the Rhône River, which is the main freshwater source of the Mediterranean Sea.
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