خيارات البحث
النتائج 1211 - 1220 من 7,351
The association between bisphenol A exposure and oxidative damage in rats/mice: A systematic review and meta-analysis النص الكامل
2022
Zhang, Huan | Yang, Rui-fu | Shi, Wanying | Zhou, Xin | Sun, Suju
Numerous studies reported that BPA could cause oxidative damage to different tissues in rats/mice. This study aimed to perform a systematic review and meta-analysis of BPA exposure on oxidative damage in rats/mice. A comprehensive literature search was conducted using PubMed, Embase, and Web of Science databases from their inception date until July 18, 2020. 20 eligible articles were included in this study. The results showed that BPA could significantly increase the level of MDA (SMD, 16.88; 95%CI, 12.06–21.71), but there was a significant reduction in the contents of antioxidants, such as GR (−10.46, −13.91 ∼ −7.02), CAT (−8.48, −11.66 ∼ −5.30), GPx (−9.37, −11.95 ∼ −6.80), GST (−7.59, −14.51 ∼ −0.67), GSH (−10.64, −13.96 ~ −7.33), and SOD (−6.48, −8.37 ∼ −4.58) in rats/mice. Our study provided clear evidence that BPA exposure could significantly induce oxidative damage in rats/mice. And we also found that the degree of oxidative damage was related to BPA dose, target tissue, intervention means, and exposure duration of BPA.
اظهر المزيد [+] اقل [-]Significant impact of seasonality, verticality and biofilm on element accumulation of aquatic macrophytes النص الكامل
2022
Engloner, Attila I. | Németh, Kitti | Óvári, Mihály
Submersed macrophytes accumulate large amounts of macro- and trace elements from the environment and, therefore, are frequently used as indicators of water pollution and tools to remove pollutants from contaminated waters. This study provides evidences that the quantity of macro- and trace elements accumulated in the macrophyte Ceratophyllum demersum depends strongly on the seasonality, on the vertical position of the plant material and on the biofilm cover. Element contents of macrophytes with and without biofilm cover and that of vertical plant sections were investigated by an ICP-MS technique in three different habitats, at the beginning and at the end of the vegetation period. Results demonstrated that the element concentrations of Ceratophyllum demersum dropped to one-half and one-eighth by the end of the summer; and the amount of certain elements in the lower part of plants were up to six times higher than in the upper and in plants with well-developed epiphytic microbial community 2-5-fold higher than in plants without biofilm.These results help in phytoremediation practice and in setting up future biomonitoring studies. When it is necessary to calculate the exact amount of elements which can be accumulated by plants in a polluted environment or should be removed from a contaminated water by harvesting macrophytes, it is of high importance to consider the month of the study, the plant parts harvested and the biofilm cover.
اظهر المزيد [+] اقل [-]Genotoxic potential of bisphenol A: A review النص الكامل
2022
Ďurovcová, Ivana | Kyzek, Stanislav | Fabová, Jana | Makuková, Jana | Gálová, Eliška | Ševčovičová, Andrea
Bisphenol A (BPA), as a major component of some plastic products, is abundant environmental pollutant. Due to its ability to bind to several types of estrogen receptors, it can trigger multiple cellular responses, which can contribute to various manifestations at the organism level. The most studied effect of BPA is endocrine disruption, but recently its prooxidative potential has been confirmed. BPA ability to induce oxidative stress through increased ROS production, altered activity of antioxidant enzymes, or accumulation of oxidation products of biomacromolecules is observed in a wide range of organisms – estrogen receptor-positive and -negative. Subsequently, increased intracellular oxidation can lead to DNA damage induction, represented by oxidative damage, single- and double-strand DNA breaks. Importantly, BPA shows several mechanisms of action and can trigger adverse effects on all organisms inhabiting a wide variety of ecosystem types. Therefore, the main aim of this review is to summarize the genotoxic effects of BPA on organisms across all taxa.
اظهر المزيد [+] اقل [-]Diesel exhaust particulate emissions and in vitro toxicity from Euro 3 and Euro 6 vehicles النص الكامل
2022
Zerboni, Alessandra | Rossi, Tommaso | Bengalli, Rossella | Catelani, Tiziano | Rizzi, Cristiana | Priola, Marco | Casadei, Simone | Mantecca, Paride
Incomplete combustion processes in diesel engines produce particulate matter (PM) that significantly contributes to air pollution. Currently, there remains a knowledge gap in relation to the physical and chemical characteristics and also the biological reactivity of the PM emitted from old- and new-generation diesel vehicles. In this study, the emissions from a Euro 3 diesel vehicle were compared to those from a Euro 6 car during the regeneration of a diesel particulate filter (DPF). Different driving cycles were used to collect two types of diesel exhaust particles (DEPs). The particle size distribution was monitored using an engine exhaust particle sizer spectrometer and an electrical low-pressure impactor. Although the Euro 6 vehicle emitted particulates only during DPF regeneration that primarily occurs for a few minutes at high speeds, such emissions are characterized by a higher number of ultrafine particles (<0.1 μm) compared to those from the Euro 3 diesel vehicle. The emitted particles possess different characteristics. For example, Euro 6 DEPs exhibit a lower PAH content than do Euro 3 samples; however, they are enriched in metals that were poorly detected or undetected in Euro 3 emissions. The biological effects of the two DEPs were investigated in human bronchial BEAS-2B cells exposed to 50 μg/mL of PM (corresponding to 5.2 μg/cm²), and the results revealed that Euro 3 DEPs activated the typical inflammatory and pro-carcinogenic pathways induced by combustion-derived particles, while Euro 6 DEPs were less effective in regard to activating such biological responses. Although further investigations are required, it is evident that the different in vitro effects elicited by Euro 3 and Euro 6 DEPs can be correlated with the variable chemical compositions (metals and PAHs) of the emitted particles that play a pivotal role in the inflammatory and carcinogenic potential of airborne PM.
اظهر المزيد [+] اقل [-]Exposure to bedroom light pollution and cardiometabolic risk: A cohort study from Chinese young adults النص الكامل
2022
Xu, Yu-xiang | Yu, Yang | Huang, Yan | Wan, Yu-hui | Su, Pu-yu | Tao, Fang-biao | Sun, Ying
Indoor light environment has altered dramatically and exposure to light at night (LAN) potential leads to the progression of cardiometabolic conditions. However, few studies have investigated the effect of bedroom LAN exposure on cardiometabolic risk. To estimate the associations between multi-period bedroom LAN exposure with cardiometabolic risk among Chinese young adults. We objectively measured multi-period bedroom LAN intensity using portable illuminance meter in an ongoing prospective cohort (n = 484). At one-year follow-up, 230 young adults provided fasting blood samples for quantification of cardiometabolic parameters. Cardiometabolic (CM)-risk score was derived as the sum of standardized sex-specific z-scores for waist circumference (WC), mean arterial pressure (MAP), high-density lipoprotein cholesterol (HDL-C), triglyceride (TG) and homeostasis model assessment for insulin resistance (HOMA-IR), with HDL-C multiplied by – 1. Multivariate and univariable linear regression models were used to examine associations of multi-period bedroom LAN exposure with cardiometabolic risk. Exposure to higher bedroom LAN intensity is associated with 1.47-unit increase in CM-risk score (95% CI: 0.69–2.25; P < 0.001). Besides, post-bedtime light exposure was associated with elevated fasting insulin (PBL-1h: β = 0.06, 95% CI: 0.01–0.10; PBL-4h: β = 0.33, 95% CI: 0.19–0.47) and HOMA-IR (PBL-1h: β = 0.013, 95% CI: 0–0.03; PBL-4h: β = 0.07, 95% CI: 0.04–0.11) while pre-awake light exposure was associated with elevated total cholesterol (PAL-1h: β = 0.03, 95% CI: 0.02–0.04; PAL-2h: β = 0.02, 95% CI: 0.01–0.03), triglyceride (PAL-1h: β = 0.015, 95% CI: 0.01–0.02; PAL-2h: β = 0.01, 95% CI: 0–0.02) and low-density lipoprotein cholesterol (PAL-1h: β = 0.02, 95% CI: 0.01–0.03; PAL-2h: β = 0.02, 95% CI: 0.01–0.03). Among young adults, bedroom LAN exposure was significantly associated with higher cardiometabolic risk. Furthermore, different periods of bedroom light exposure have time-dependent effect on cardiometabolic risk. Further research is needed to confirm our findings and to elucidate potential mechanisms.
اظهر المزيد [+] اقل [-]Effect of arbuscular mycorrhizal fungi in roots on antioxidant enzyme activity in leaves of Robinia pseudoacacia L. seedlings under elevated CO2 and Cd exposure النص الكامل
2022
Wang, Lu | Jia, Xia | Zhao, Yonghua | Zhang, Chunyan | Zhao, Jiamin
Arbuscular mycorrhizal fungi (AMF) are easily influenced by increasing atmospheric CO₂ concentration and heavy metals including cadmium (Cd), which can regulate antioxidant enzyme in host plants. Although the effect of AMF under individual conditions such as elevated CO₂ (ECO₂) and Cd on antioxidant enzyme in host plants has been reported widely, the effect of AMF under ECO₂ + Cd receives little attention. In this study, a pot experiment was conducted to study the effect of AMF community in roots on superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) activities in leaves of 135-d Robinia pseudoacacia L. seedlings under ECO₂ + Cd. The activities of SOD and CAT increased and POD activity and the richness and diversity of AMF community decreased under ECO₂ + Cd relative to Cd alone. The richness and diversity of AMF were negatively related to Cd content in roots and leaves. The richness and OTUs of AMF community positively and AMF gene abundance negatively affected POD activity under the combined treatments. Superoxide dismutase and POD activities were negatively and positively related to Archaeospora and Scutellospora, respectively, under ECO₂ + Cd. Cadmium in roots and leaves was negatively and significantly related to Glomus, Scutellospora, and Claroideoglomus abundance under ECO₂ + Cd. Overall, AMF diversity and Archaeospora and Scutellospora in roots significantly influenced SOD, POD, and CAT activities. The response of AM symbiosis to ECO₂ might regulate antioxidant capacity in host plants upon Cd exposure. Glomus, Scutellospora, and Claroideoglomus might be applied to phytoremediation of Cd-contaminated soils.
اظهر المزيد [+] اقل [-]Inorganic and methylated mercury dynamics in estuarine water of a salt marsh in Massachusetts, USA النص الكامل
2022
Wang, Ting | Obrist, Daniel
Salt marsh estuaries serve as sources and sinks for nutrients and elements to and from estuarine water, which enhances and alleviates watershed fluxes to the coastal ocean. We assessed sources and sinks of mercury in the intertidal Plum Island Sound estuary in Massachusetts, the largest salt marsh estuary of New England, using 25-km spatial water sampling transects. Across all seasons, dissolved (FHg) and total (THg) mercury concentrations in estuarine water were highest and strongly enhanced in upper marshes (1.31 ± 0.20 ng L⁻¹ and 6.56 ± 3.70 ng L⁻¹, respectively), compared to riverine Hg concentrations (0.86 ± 0.17 ng L⁻¹ and 0.88 ± 0.34 ng L⁻¹, respectively). Mercury concentrations declined from upper to lower marshes and were lowest in ocean water (0.38 ± 0.10 ng L⁻¹ and 0.56 ± 0.25 ng L⁻¹, respectively). Conservative mixing models using river and ocean water as endmembers indicated that internal estuarine Hg sources strongly enhanced estuarine water Hg concentrations. For FHg, internal estuarine Hg contributions were estimated at 26 g yr⁻¹ which enhanced Hg loads from riverine sources to the ocean by 44%. For THg, internal sources amounted to 251 g yr⁻¹ and exceeded riverine sources six-fold. Proposed sources for internal estuarine mercury contributions include atmospheric deposition to the large estuarine surface area and sediment re-mobilization, although sediment Hg concentrations were low (average 23 ± 2 μg kg⁻¹) typical of uncontaminated sediments. Soil mercury concentrations under vegetation, however, were ten times higher (average 200 ± 225 μg kg⁻¹) than in intertidal sediments suggesting that high soil Hg accumulation might drive lateral export of Hg to the ocean. Spatial transects of methylated Hg (MeHg) showed no concentration enhancements in estuarine water and no indication of internal MeHg sources or formation. Initial mass balance considerations suggest that atmospheric deposition may either be in similar magnitude, or possibly exceed lateral tidal export which would be consistent with strong Hg accumulation observed in salt marsh soils sequestering Hg from current and past atmospheric deposition.
اظهر المزيد [+] اقل [-]Varroa mite and deformed wing virus infestations interactively make honey bees (Apis mellifera) more susceptible to insecticides النص الكامل
2022
Zhu, Yu-Cheng | Yao, Jianxiu | Wang, Yanhua
Varroa mite is one of the major adverse factors causing honey bee population decline. In this study, Varroa destructor-infested and uninfested honey bee colonies were established by selective applying miticide (Apivar® amitraz). Mite population was monitored monthly (April–October 2016), and deformed wing virus (DWV) loading was detected seasonally (April, July, and October). Four immunity- and two physiology-related gene expressions, natural mortality, and susceptibility to five insecticides were comparatively and seasonally examined in field-collected honey bee workers. Results showed that Apivar-treated bee colonies had minor or undetectable mite and DWV (using RT-qPCR) infestations in whole bee season, while untreated colonies had substantially higher mite and DWV infestations. In untreated colonies, Varroa mite population irregularly fluctuated over the bee season with higher mite counts in Jun (318 ± 89 mites dropped in 48 h) or August (302) than that (25 ± 4 or 34) in October, and mite population density was not dynamically or closely correlated with the seasonal shift of honey bee natural mortality (regression slope = −0.5212). Unlike mite, DWV titer in untreated colonies progressively increased over the bee season, and it was highly correlated (R² = 1) with the seasonal increase of honey bee natural mortality. Significantly lower gene expressions of dor, PPO, mfe, potentially PPOa and eat as well, in untreated colonies also indicated an association of increased DWV infestation with decreased physiological and immunity-related functions in late-season honey bees. Furthermore, bees with lower mite/DWV infestations exhibited generally consistently lower susceptibilities (contact and oral toxicities) to five representative insecticides than the bees without Apivar treatment. All of these data from this study consistently indicated an interaction of Varroa/viral infestations with insecticide susceptibilities in honey bees, potentially through impairing bee's physiology and immunity, emphasizing the importance of mite control in order to minimize honey bee decline.
اظهر المزيد [+] اقل [-]Simultaneous capturing of mixed contaminants from wastewater using novel one-pot chitosan functionalized with EDTA and graphene oxide adsorbent النص الكامل
2022
Verma, Monu | Ashwani Kumar, | Lee, Ingyu | Kumar, Vinod | Park, Ju-Hyun | Kim, Hyunook
The emergence of inorganic and organic contaminants has raised great concerns owing to their adverse impact on human health and ecological security. Herein, first time one-pot process was applied for chitosan (CS) functionalization using graphene oxide (GO) and ethylenediaminetetraacetic acid (EDTA) for simultaneous capturing of toxic inorganic (lead (Pb²⁺) and cadmium (Cd²⁺)) and organic (ciprofloxacin (CIP) and sildenafil (SDF)) contaminants from wastewater. In this approach, we believe that CS would work as a backbone, GO would capture both inorganic and organic contaminants via electrostatic interactions, while EDTA would make complexation with heavy metals. Various parameters including pH, reaction time, concentration, reusability etc. were evaluated to achieve the best experimental result in monocomponent system. The prepared adsorbent displayed an excellent monolayer adsorption capacity of 351.20 and 264.10 mg g⁻¹ for Pb²⁺ and Cd²⁺, respectively, while a heterogeneous sorption capacity of 75.40 and 40.90 mg g⁻¹ for CIP and SDF, respectively. The kinetics data fitted well to Pseudo-second order (PSO) kinetics model for both types of contaminants and gave faster interaction towards metal ions (higher k₂) than organic contaminants. Experimental results showed excellent adsorption efficiencies at environmental levels in the capturing of both inorganic and organic contaminants at the same time from polluted water. The capturing mechanism of both types of contaminants was explained by elemental mapping, EDS, and FT−IR spectra. Overall, easy synthesis, excellent capturing capacity, and reusability imply that the prepared adsorbent has a sufficient potential for the treatment of co-existing toxic contaminants in water.
اظهر المزيد [+] اقل [-]Characterization and biodegradability assessment of water-soluble fraction of oily sludge using stir bar sorptive extraction and GCxGC-TOF MS النص الكامل
2022
Chand, Priyankar | Dutta, Suryendu | Mukherji, Suparna
Percolation of water through oily sludge during storage and handling of the sludge can cause soil and groundwater contamination. In this study, oily sludge from a refinery was equilibrated with water to obtain the water-soluble fraction (WSF) of oily sludge. The WSF had dissolved organic carbon (DOC) of 166 mg/L. Human cell line-based toxicity assay revealed IC₅₀ of 41 mg/L indicating its toxic nature. The predominant compounds in WSF of oily sludge included isomers of methyl, dimethyl and trimethyl quinolines and naphthalenes along with phenol derivatives and other polynuclear aromatic hydrocarbons (PAHs). Biodegradation of WSF of oily sludge was studied using a consortium of Rhodococcus ruber, Bacillus sp. and Bacillus cereus isolated from the refinery sludge. The consortium of the three strains resulted in 70% degradation over 15 days with a first-order degradation rate of 0.161 day⁻¹. Further analysis of the WSF was performed using the stir-bar sorptive extraction (SBSE) followed by GCxGC-TOF MS employing a PDMS Twister. The GCxGC analysis showed that Bacillus cereus was capable of degrading the quinoline, phenol and naphthalene derivatives in WSF of oily sludge at a faster rate compared to pyridine and benzoquinoline derivatives. Quinoline, phenol, biphenyl, naphthalene, pyridine and benzoquinolines derivatives in the WSF of oily sludge were reduced by 87%, 92%, 88%, 77%, 40% and 62%, respectively with respect to the controls. The WSF of oily sludge contained, n-alkanes, ranging from n-C12 to n-C18 which were removed within 2 days of biodegradation.
اظهر المزيد [+] اقل [-]