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النتائج 651 - 660 من 7,240
Metal-free single heteroatom (N, O, and B)-doped coconut-shell biochar for enhancing the degradation of sulfathiazole antibiotics by peroxymonosulfate and its effects on bacterial community dynamics
2022
Hung, Chang-Mao | Chen, Chiu-Wen | Huang, Jinbao | Dong, Cheng-Di
Metal-free single heteroatom (N, O, and B)-doped coconut-shell biochar (denoted as N-CSBC, O-CSBC, and B-CSBC, respectively) were fabricated in a one-step pyrolysis process to promote peroxymonosulfate (PMS) activation for the elimination of sulfathiazole (STZ) from aquaculture water. B-CSBC exhibited remarkably high catalytic activity with 92% of STZ degradation in 30 min attributed to the presence of meso-/micro-pores and B-containing functional groups (including B–N, B–C, and B₂O₃ species). Radical quenching tests revealed SO₄•⁻, HO•, and ¹O₂ being the major electron acceptors contributing to STZ removal by PMS over B-CSBC catalyst. The B-CSBC catalyst has demonstrated high sustainability in multiple consecutive treatment cycles. High salinity and the presence of inorganic ions such as chloride, enhanced the performance of the sulfate radical-carbon-driven advanced oxidation processes (SR–CAOPs) as pretreatment strategy that significantly facilitated the removal of STZ from aquaculture water. Furthermore, a potential sulfonamide-degrading microorganism, Cylindrospermum_stagnale, belonging to the phylum Cyanobacteria, was the dominant functional bacteria according to the results of high-throughput 16S rRNA gene sequencing conducted after the B-CSBC/PMS treatment. This study provides new insights into the SR–CAOP combined with bioprocesses for removing STZ from aqueous environments.
اظهر المزيد [+] اقل [-]Copper stress in grapevine: Consequences, responses, and a novel mitigation strategy using 5-aminolevulinic acid
2022
Yang, Yuxian | Fang, Xiang | Chen, Mengxia | Wang, Lingyu | Xia, Jiaxin | Wang, Zicheng | Fang, Jinggui | Tran, Lam-son Phan | Shangguan, Lingfei
Improper application of copper-based fungicides has made copper stress critical in viticulture, necessitating the need to identify substances that can mitigate it. In this study, leaves of ‘Shine Muscat’ (‘SM’) grapevine seedlings were treated with CuSO₄ solution (10 mM/L), CuSO₄ + 5-aminolevulinic acid (ALA) (50 mg/L), and distilled water to explore the mitigation effect of ALA. Physiological assays demonstrated that ALA effectively reduced malondialdehyde accumulation and increased peroxidase and superoxide dismutase activities in grapevine leaves under copper stress. Copper ion absorption, transport pathways, chlorophyll metabolism pathways, photosynthetic system, and antioxidant pathways play key roles in ALA alleviated-copper stress. Moreover, expression changes in genes, such as CHLH, ALAD, RCA, and DHAR, play vital roles in these processes. Furthermore, abscisic acid reduction caused by NCED down-regulation and decreased naringenin, leucopelargonidin, and betaine contents confirmed the alleviating effect of ALA. Taken together, these results reveal how grapevine responds to copper stress and the alleviating effects of ALA, thus providing a novel means of alleviating copper stress in viticulture.
اظهر المزيد [+] اقل [-]Biochemical toxicity and transcriptome aberration induced by dinotefuran in Bombyx mori
2022
Xu, Shiliang | Hao, Zhihua | Li, Yinghui | Zhou, Yanyan | Shao, Ruixi | Chen, Rui | Zheng, Meidan | Xu, Yusong | Wang, Huabing
Dinotefuran is a third-generation neonicotinoid pesticide and is increasingly used in agricultural production, which has adverse effects on nontarget organisms. However, the research on the impact of dinotefuran on nontarget organisms is still limited. Here the toxic effects of dinotefuran on an important economic species and a model lepidopteran insect, Bombyx mori, were investigated. Exposure to different doses of dinotefuran caused physiological disorders or death. Cytochrome P450, glutathione S-transferase, carboxylesterase, and UDP glycosyl-transferase activities were induced in the fat body at early stages after dinotefuran exposure. By contrast, only glutathione S-transferase activity was increased in the midgut. To overcome the lack of sensitivity of the biological assays at the individual organism level, RNA sequencing was performed to measure differential expressions of mRNA from silkworm larvae after dinotefuran exposure. Differential gene expression profiling revealed that various detoxification enzyme genes were significantly increased after dinotefuran exposure, which was consistent with the upregulation of the detoxifying enzyme. The global transcriptional pattern showed that the physiological responses induced by dinotefuran toxicity involved multiple cellular processes, including energy metabolism, oxidative stress, detoxification, and other fundamental physiological processes. Many metabolism processes, such as carbon metabolism, fatty acid biosynthesis, pyruvate metabolism, and the citrate cycle, were partially repressed in the midgut or fat body. Furthermore, dinotefuran significantly activated the MAPK/CREB, CncC/Keap1, PI3K/Akt, and Toll/IMD pathways. The links between physiological, biochemical toxicity and comparative transcriptomic analysis facilitated the systematic understanding of the integrated biological toxicity of dinotefuran. This study provides a holistic view of the toxicity and detoxification metabolism of dinotefuran in silkworm and other organisms.
اظهر المزيد [+] اقل [-]Epigenome–wide DNA methylation signature of plasma zinc and their mediation roles in the association of zinc with lung cancer risk
2022
Meng, Hua | Wei, Wei | Li, Guyanan | Fu, Ming | Wang, Chenming | Hong, Shiru | Guan, Xin | Bai, Yansen | Feng, Yue | Zhou, Yuhan | Cao, Qiang | Yuan, Fangfang | He, Meian | Zhang, Xiaomin | Wei, Sheng | Li, Yangkai | Kwok, Woon
Essential trace element zinc is associated with decreased lung cancer risk, but underlying mechanisms remain unclear. This study aimed to investigate role of DNA methylation in zinc-lung cancer association. We conducted a case-cohort study within prospective Dongfeng-Tongji cohort, including 359 incident lung cancer cases and a randomly selected sub–cohort of 1399 participants. Epigenome-wide association study (EWAS) was used to examine association of plasma zinc with DNA methylation in peripheral blood. For the zinc-related CpGs, their mediation effects on zinc-lung cancer association were assessed; their diagnostic performance for lung cancer was testified in the case-cohort study and further validated in another 126 pairs of lung cancer case-control study. We identified 28 CpGs associated with plasma zinc at P < 1.0 × 10⁻⁵ and seven of them (cg07077080, cg01077808, cg17749033, cg15554270, cg26125625, cg10669424, and cg15409013 annotated to GSR, CALR3, SLC16A3, PHLPP2, SLC12A8, VGLL4, and ADAMTS16, respectively) were associated with incident risk of lung cancer. Moreover, the above seven CpGs were differently methylated between 126 pairs of lung cancer and adjacent normal lung tissues and had the same directions with EWAS of zinc. They could mediate a separate 7.05%∼22.65% and a joint 29.42% of zinc-lung cancer association. Compared to using traditional factors, addition of methylation risk score exerted improved discriminations for lung cancer both in case-cohort study [area under the curve (AUC) = 0.818 vs. 0.738] and in case-control study (AUC = 0.816 vs. 0.646). Our results provide new insights for the biological role of DNA methylation in the inverse association of zinc with incident lung cancer.
اظهر المزيد [+] اقل [-]Impact of benzo[a]pyrene with other pollutants induce the molecular alternation in the biological system: Existence, detection, and remediation methods
2022
Saravanakumar, Kandasamy | Sivasantosh, Sugavaneswaran | Sathiyaseelan, Anbazhagan | Sankaranarayanan, Alwarappan | Naveen, Kumar Vishven | Zhang, Xin | Jamla, Monica | Vijayasarathy, Sampathkumar | Vishnu Priya, Veeraraghavan | MubarakAli, Davoodbasha | Wang, Myeong-Hyeon
The exposure of benzo [a]pyrene (BaP) in recent times is rather unavoidable than ever before. BaP emissions are sourced majorly from anthropogenic rather than natural provenance from wildfires and volcanic eruptions. A major under-looked source is via the consumption of foods that are deep-fried, grilled, and charcoal smoked foods (meats in particular). BaP being a component of poly aromatic hydrocarbons has been classified as a Group I carcinogenic agent, which has been shown to cause both systemic and localized effects in animal models as well as in humans; has been known to cause various forms of cancer, accelerate neurological disorders, invoke DNA and cellular damage due to the generation of reactive oxygen species and involve in multi-generational phenotypic and genotypic defects. BaP's short and accumulated exposure has been shown in disrupting the fertility of gamete cells. In this review, we have discussed an in-depth and capacious run-through of the various origins of BaP, its economic distribution and its impact as well as toxicological effects on the environment and human health. It also deals with a mechanism as a single compound and its ability to synergize with other chemicals/materials, novel sensitive detection methods, and remediation approaches held in the environment.
اظهر المزيد [+] اقل [-]Per- and polyfluoroalkyl substance (PFAS) retention by colloidal activated carbon (CAC) using dynamic column experiments
2022
Niarchos, Georgios | Ahrens, Lutz | Kleja, Dan Berggren | Fagerlund, Fritjof
Developing effective remediation methods for per- and polyfluoroalkyl substance (PFAS)-contaminated soils is a substantial step towards counteracting their widespread occurrence and protecting our ecosystems and drinking water sources. Stabilisation of PFAS in the subsurface using colloidal activated carbon (CAC) is an innovative, yet promising technique, requiring better understanding. In this study, dynamic soil column tests were used to assess the retardation of 10 classical perfluoroalkyl acids (PFAAs) (C₅–C₁₁ perfluoroalkyl carboxylic acids (PFCAs) and C₄, C₆, C₈ perfluoroalkane sulfonates (PFSAs)) as well as two alternative PFAS (6:2 and 8:2 fluorotelomer sulfonates) using CAC at 0.03% w/w, to investigate the fate and transport of PFAS under CAC treatment applications. Results showed high retardation rates for long-chain PFAS and eight times higher retardation for the CAC-treated soil compared to the non-treated reference soil for the ∑PFAS. Replacement of shorter chain perfluorocarboxylic acids (PFCAs), such as perfluoropentanoic acid (PFPeA), by longer chained PFAS was observed, indicating competition effects. Partitioning coefficients (Kd values) were calculated for the CAC fraction at ∼10³–10⁵ L kg⁻¹ for individual PFAS, while there was a significant positive correlation (p < 0.05) between perfluorocarbon chain length and Kd. Mass balance calculations showed 37% retention of ∑PFAS in treated soil columns after completion of the experiments and 99.7% higher retention rates than the reference soil. Redistribution and elution of CAC were noticed and quantified through organic carbon analysis, which showed a 23% loss of carbon during the experiments. These findings are a step towards better understanding the extent of CAC's potential for remediation of PFAS-contaminated soil and groundwater and the limitations of its applications.
اظهر المزيد [+] اقل [-]NO2 air pollution drives species composition, but tree traits drive species diversity of urban epiphytic lichen communities
2022
Sebald, Veronica | Goss, Andrea | Ramm, Elisabeth | Gerasimova, Julia V. | Werth, Silke
Lichens serve as important bioindicators of air pollution in cities. Here, we studied the diversity of epiphytic lichens in the urban area of Munich, Bavaria, southern Germany, to determine which factors influence species composition and diversity. Lichen diversity was quantified in altogether 18 plots and within each, five deciduous trees were investigated belonging to on average three tree species (range 1–5). Of the 18 plots, two were sampled in control areas in remote areas of southern Germany. For each lichen species, frequency of occurrence was determined in 10 quadrats of 100 cm² on the tree trunk. Moreover, the cover percentage of bryophytes was determined and used as a variable to represent potential biotic competition. We related our diversity data (species richness, Shannon index, evenness, abundance) to various environmental variables including tree traits, i.e. bark pH levels and species affiliation and air pollution data, i.e. NO₂ and SO₂ concentrations measured in the study plots. The SO₂ levels measured in our study were generally very low, while NO₂ levels were rather high in some plots. We found that the species composition of the epiphytic lichen communities was driven mainly by NO₂ pollution levels and all of the most common species in our study were nitrophilous lichens. Low NO₂ but high SO₂ values were associated with high lichen evenness. Tree-level lichen diversity and abundance were mainly determined by tree traits, not air pollution. These results confirm that ongoing NO₂ air pollution within cities is a major threat to lichen diversity, with non-nitrophilous lichens likely experiencing the greatest risk of local extinctions in urban areas in the future. Our study moreover highlights the importance of large urban green spaces for species diversity. City planners need to include large green spaces when designing urban areas, both to improve biodiversity and to promote human health and wellbeing.
اظهر المزيد [+] اقل [-]Combined exposure of lead and high-fat diet enhanced cognitive decline via interacting with CREB-BDNF signaling in male rats
2022
Liu, Rundong | Bai, Lin | Liu, Mengchen | Wang, Ruike | Wu, Yingying | Li, Qiong | Ba, Yue | Zhang, Huizhen | Zhou, Guoyu | Yu, Fangfang | Huang, Hui
The health risks to populations induced by lead (Pb) and high-fat diets (HFD) have become a global public health problem. Pb and HFD often co-exist and are co-occurring risk factors for cognitive impairment. This study investigates effect of combined Pb and HFD on cognitive function, and explores the underlying mechanisms in terms of regulatory components of synaptic plasticity and insulin signaling pathway. We showed that the co-exposure of Pb and HFD further increased blood Pb levels, caused body weight loss and dyslipidemia. The results from Morris water maze (MWM) test and Nissl staining disclosed that Pb and HFD each contributed to cognitive deficits and neuronal damage and combined exposure enhanced this toxic injury. Pb and HFD decreased the levels of synapsin-1, GAP-43 and PSD-95 protein related to synaptic properties and SIRT1, NMDARs, phosphorylated CREB and BDNF related to synaptic plasticity regulatory, and these decreases was greater when combined exposure. Additionally, we revealed that Pb and HFD promoted IRS-1 phosphorylation and subsequently reduced downstream PI3K-Akt kinases phosphorylation in hippocampus and cortex of rats, and this process was aggravated when co-exposure. Collectively, our data suggested that combined exposure of Pb and HFD enhanced cognitive deficits, pointing to additive effects in rats than the individual stress effects related to multiple signaling pathways with CREB-BDNF signaling as the hub. This study emphasizes the need to evaluate the effects of mixed exposures on brain function in realistic environment and to better inform prevention of neurological disorders via modulating central pathway, such as CREB/BDNF signaling.
اظهر المزيد [+] اقل [-]Eutrophic levels and algae growth increase emissions of methane and volatile sulfur compounds from lakes
2022
Wang, Jing | Wei, Zhi-Peng | Chu, Yi-Xuan | Tian, Guangming | He, Ruo
Eutrophic lakes are hot spots of CH₄ and volatile sulfur compound (VSC) emissions, especially during algal blooms and decay. However, the response of CH₄ and VSC emissions to lake eutrophication and algae growth as well as the underlying mechanisms remain unclear. In this study, the emissions of CH₄ and VSCs from four regions of Lake Taihu with different eutrophic levels were investigated in four months (i.e., March, May, August and December). The CH₄ emissions ranged from 20.4 to 126.9 mg m⁻² d⁻¹ in the investigated sites and increased with eutrophic levels and temperature. H₂S and CS₂ were the dominant volatile sulfur compounds (VSCs) emitted from the lake. The CH₄ oxidation potential of water ranged from 2.1 to 14.9 μg h⁻¹ L⁻¹, which had positive correlations with trophic level index and the environmental variables except for the NH₄⁺-N concentration. Eutrophic levels could increase the abundances of bacteria and methanotrophs in lake water. α-Proteobacteria methanotroph Methylocystis was more abundant than γ-Proteobacteria methanotrophs in March and May, while the latter was more abundant in August and November. The relative abundance of Cyanobacteria, including Microcystis, A. granulata var. angustissima and Cyanobium had significantly positive correlations with temperature, turbidity, SO₄²⁻-S, and total sulfur. Partial least squares path modelling revealed that the algal growth could promote VSC emissions, which had a positive correlation with CH₄ oxidation potential, likely due to the positive correlation between the CH₄ and VSC emissions from lakes. These findings indicate that water eutrophication and algae growth could increase the emissions of CH₄ and VSCs from lakes. Controlling algae growth might be an effective way to mitigate the emissions of CH₄ and VSCs from freshwater lakes.
اظهر المزيد [+] اقل [-]Thallium distribution in an estuary affected by acid mine drainage (AMD): The Ría de Huelva estuary (SW Spain)
2022
Cánovas, Carlos Ruiz | Basallote, María Dolores | Macías, Francisco | Freydier, Rémi | Parviainen, Annika | Pérez López, Rafael
This study investigates the behavior of Tl in the Ría de Huelva (SW Spain), one of the most metal polluted estuaries in the world. Dissolved Tl concentration displayed a general decrease across the estuary during the dry season (DS); from 5.0 to 0.34 μg/L in the Tinto and Odiel estuaries, respectively, to 0.02 μg/L in the channel where the rivers join. A slighter decrease was observed during the wet season (WS) (from 0.72 to 0.14 μg/L to 0.02 μg/L) due to the dilution effect of rainfalls in the watersheds. These values are 3 orders of magnitude higher than those reported in other estuaries worldwide. Different increases in Tl concentrations with salinity were observed in the upper reaches of the Tinto and Odiel estuaries, attributed to desorption processes from particulate matter. Chemical and mineralogical evidences of particulate matter, point at Fe minerals (i.e., jarosite) as main drivers of Tl particulate transport in the estuary. Unlike other estuaries worldwide, where a fast sorption process onto particulate matter commonly takes place, Tl is mainly desorbed from particulate matter in the Tinto and Odiel estuaries. Thus, Tl may be released back from jarositic particulate matter across the salinity gradient due to the increasing proportion of unreactive TlCl⁰ and K⁺ ions, which compete for adsorption sites with Tl⁺ at increasing salinities. A mixing model based on conservative elements revealed a 6-fold increase in Tl concentrations related to desorption processes. However, mining spills like that occurred in May 2017 may contribute to enhance dissolved and particulate Tl concentrations in the estuary as well as to magnify these desorption processes (up to around 1100% of Tl release), highlighting the impact of the mine spill on the remobilization of Tl from the suspended matter to the water column.
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