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Chicoric acid prevents methotrexate hepatotoxicity via attenuation of oxidative stress and inflammation and up-regulation of PPARγ and Nrf2/HO-1 signaling Texto completo
2020
Hussein, Omnia E. | Hozayen, Walaa G. | Bin-Jumah, May N. | Germoush, Mousa O. | Abd El-Twab, Sanaa M. | Mahmoud, Ayman M.
Chicoric acid (CA) is a natural antioxidant with promising hepatoprotective activity. We investigated the potential of CA to prevent methotrexate (MTX) hepatotoxicity, pointing to the role of Nrf2/HO-1 signaling and PPARγ. Rats received CA for 15 days and were then injected with MTX at day 16. Blood and tissue samples were collected for analysis at day 19. CA ameliorated liver function markers and mitigated histological alterations in MTX-induced rats. Pre-treatment with CA suppressed reactive oxygen species and lipid peroxidation and enhanced antioxidants in MTX-induced rats. Moreover, CA upregulated hepatic Nrf2, HO-1, NQO-1, and PPARγ, and attenuated inflammation. Consequently, CA inhibited apoptosis by increasing Bcl-2 expression and suppressing Bax, cytochrome c, and caspase-3 in MTX-administered rats. In conclusion, CA prevented oxidative stress, inflammation, and liver injury induced by MTX by activating Nrf2 /HO-1 signaling and PPARγ.
Mostrar más [+] Menos [-]Toxic gas and respirable dust concentrations and emissions from broiler and cage-layer barns in the Canadian Prairies Texto completo
2020
Huang, Dandan | Guo, Huiqing
This study monitored concentrations and emissions of ammonia (NH₃), hydrogen sulfide (H₂S), and respirable dust for a commercial broiler and a cage-layer barn in the Canadian Prairies over a year between March 2015 and February 2016. Seasonal concentration and emission profiles were acquired by monthly measurements, while diurnal profiles were generated in different seasons. The indoor air quality was evaluated considering both the individual and the additive health effect (respiratory irritation) of the three air pollutants. In winter, both 8-h and 15-min exposure limits (threshold concentrations) of NH₃ were exceeded in the broiler barn; the highest additive level was more than two times of the limit. Seasonal average emissions of NH₃, H₂S, and respirable dust were 57 g d⁻¹ AU⁻¹, 1.35 g d⁻¹ AU⁻¹, and 1.99 g d⁻¹ AU⁻¹, respectively, for the layer barn, all with higher levels in the mild and warm seasons than in the cold season. The emission data were only obtained for the worst-case scenarios (last week of the production cycle) of the broiler barn, with annual averages of 92 g d⁻¹ AU⁻¹ for NH₃, 1.19 g d⁻¹ AU⁻¹ for H₂S, and 4.32 g d⁻¹ AU⁻¹ for respirable dust, with obvious higher NH₃ levels in winter. Additionally, manure removal once every 3–4 days for the layer barn reduced NH₃ emissions by 62% and 90% in the cold and mild seasons, respectively. This study also found significant negative influence of outdoor T (Tₒᵤₜ) on NH₃ emissions for the broiler barn but positive impact of Tₒᵤₜ on NH₃ emissions for the layer barn.
Mostrar más [+] Menos [-]Can government environmental auditing improve static and dynamic ecological efficiency in China? Texto completo
2020
Jiang, Qibo | Tan, Qingmei
As an important part of external supervision, government environmental auditing plays a significant role in the construction of ecological civilization. With the execution of environmental audit events by the National Audit Office of China (CNAO) during 2008 to 2018, we examine the impact of government environmental auditing on ecological efficiency by using multiple regression method and PSM method. Our analyses show that government environmental auditing can obviously improve both static and dynamic ecological efficiency. Further research suggests that (1) government environmental auditing has a short-term improvement effect on ecological efficiency but nothing in the long run. (2) Government environmental auditing plays a supervisory and warning role in improving ecological efficiency. Those findings provide empirical evidence for the effects of government environmental auditing on ecological efficiency. The current study has some theoretical and practical implications for the government in terms of strengthening the external supervision of environmental protection and improving the ecological efficiency.
Mostrar más [+] Menos [-]Development of electrospun lignin nanofibers for the adsorption of pharmaceutical contaminants in wastewater Texto completo
2020
Camiré, Alexandre | Espinasse, Julie | Chabot, Bruno | Lajeunesse, André
Emerging contaminants present a challenge for water preservation, threatening humans’ health and all ecosystems. They consist of a variety of molecules ranging from pharmaceutical and personal care products to pesticides and endocrine disruptors detectable in wastewater, sewage effluent, surface water, drinking water, and ground waters at trace level concentrations (e.g., ng/L, μg/L). Conventional wastewater treatment plants (WWTPs) possess low efficiency to remove them. Therefore, new technologies capable of removing such residues are needed. Lignin recognized as a renewable and abundant biopolymer is transformed through electrospinning into an anionic nanofibrous nonwoven adsorbent to extract those contaminants and dispose them safely. Electrospinning allows the manufacture of fibers at the micro- or nanoscale under the influence of an electric current. In this study, nanofibers of alkali lignin and a co-polymer, poly(vinyl alcohol), were developed and tested on the adsorption of a pharmaceutical contaminant (fluoxetine) in an aqueous solution. Results showed that the lignin nanofibers, of 156 nm in diameter, adsorbed 70% of fluoxetine in solution which corresponds to 32 ppm of contaminants removed in water.
Mostrar más [+] Menos [-]The removal of lead, copper, zinc and cadmium from aqueous solution by biochar and amended biochars Texto completo
2020
Cairns, Stuart | Robertson, Iain | Sigmund, Gabriel | Street-Perrott, Alayne
The exponential growth in the use of motor vehicles is a key contributor to freshwater degradation. Current remediation techniques require prohibitively expensive contaminant treatment and extraction. Biochar represents an inexpensive option to ameliorate contaminants from motorway runoff. Biochar from Norway spruce (Picea abies (L.) Karst.) was produced under fast pyrolysis-gasification (450–500 °C for 90 s) and amended with wood ash and basaltic rock dust to evaluate sorption of Pb, Cu, Zn and Cd. The column study, designed to mimic field conditions, confirmed that unamended biochar can bind contaminants for short periods, but that the addition of amendments, particularly wood ash, significantly improves contaminant removal. Wood ash-amended biochar removed 98–100% of all contaminants during the study, driven by pH (r = 0.73–0.74; p < 0.01 dependent on metal species) and phosphorus levels causing precipitation (r = 0.47–0.59; p < 0.01, dependent on metal species). The contaminants’ progression through the biochar subsections in the column indicated that increasing the thickness of the biochar layer increased contaminant residence time and removal.
Mostrar más [+] Menos [-]Investigation on thermodynamic performance analysis and environmental effects of various new refrigerants used in air conditioners Texto completo
2020
Shaik, Sharmas Vali | Shaik, Saboor | Gorantla, Kirankumar | Mahapatra, Debasish | Setty, Ashok BabuTalanki Puttaranga
The main aim of this present investigation is to evaluate performance and environmental impact analysis of various novel mixture refrigerants as R22 replacements theoretically. Refrigerants with lower global warming potential (GWP) can be adequate for bringing down emissions which are concerned for air conditioners. In this investigation, twenty-seven refrigerants were developed at several compositions. Important studies such as computation of CO₂ emissions using total equivalent warming impact (TEWI), toxicity and flammability analysis of various considered refrigerants were also carried out in this investigation. Performance analysis of refrigerants was conducted under different operating conditions. Results showed that the energy efficiency ratios (EERs) of refrigerants such as R1270, RM30 (R152a/R1270/RE170 of 25/71/4 by mass percentage) and RM50 (R152a/R1270/RE170 of 10/85/5 by mass percentage) were closer to that of R22 and they are relatively lower than R22 by 0.95%, 1.34% and 1.80%, respectively. Toxicity investigation exhibited that all the refrigerants studied were classified into nontoxic category (A) whereas flammability investigation revealed that all the novel refrigerant mixtures (RM10 to RM50) were classified into flammable category (A3). CO₂ emissions (TEWI) released from air conditioner working with R1270, RM30 and RM50 were 7.41%, 6.85% and 6.51%, respectively, lower than that of R22. In terms of several thermodynamic aspects, the performance of refrigerants such as R1270, RM30 and RM50 were superior to those of R22 and its various considered alternatives working under different operating conditions, although their EERs are fairly lower than R22 and hence, these refrigerants could be considered suitable environment-friendly alternatives to R22 used in air conditioners. The present study gives essential information and a road map towards the development of low GWP R22 alternative refrigerant blends from the viewpoint of toxicity, flammability, performance aspects, environmental and safety aspects, respectively.
Mostrar más [+] Menos [-]Influence of rain events on the efficiency of a compact wastewater treatment plant: a case study on a university campus aiming water reuse for agriculture Texto completo
2020
Albornoz, Louidi Lauer | Centurião, Tiago Carrard | Giacobbo, Alexandre | Zoppas-Ferreira, Jane | Bernardes, Andréa Moura
In this study, the efficiency of contaminant removal from a compact wastewater treatment plant (CWTP) in a university campus under different rain conditions was evaluated. Wastewater samples were collected weekly for 1 year and the physicochemical parameters were monitored. Removal efficiency higher than 77%, reaching values above 95% for samples with lower wastewater flow rates, was found for biological oxygen demand (BOD) and total and fecal coliforms. The pH values remained in the range of 6.0–8.0. However, pH values below 6.8 impaired the nitrification rate and, therefore, the removal of total Kjeldahl nitrogen (TKN) and ammonia was lower than the expected, with concentration values above those set by the Brazilian regulation for wastewater discharge. The results show that the flow rate of wastewater at the entrance of the CWTP is directly related to the rain events, thus affecting its efficiency, mainly in the removal of total solids, turbidity, and organic matter. The assessment of the treated wastewater reuse on site for agricultural purposes showed to be a prominent and more sustainable alternative regarding the discharge of wastewater into water bodies.
Mostrar más [+] Menos [-]Human health risk assessment of heavy metals in raw milk of buffalo feeding at wastewater-irrigated agricultural farms in Pakistan Texto completo
2020
Iqbal, Zafar | Abbas, Farhat | Ibrahim, Muhammad | Qureshi, Tahir Imran | Gul, Matin | Mahmood, Abid
Wastewater irrigation to grow fodder for animals and cattle farming is common practice in Pakistan. Hence, this study was conducted in Multan, Pakistan, to assess heavy metal pollution, human health risk and the total target health quotient (TTHQ) of heavy metals in raw milk of buffalo feeding at different agricultural farms and to identify sources of toxicity in milk. Samples of raw milk (n = 60) were analyzed for Cd, Cr, Cu, Mn, Ni, and Pb by ICP-OES, Perkin Elmer, USA. The TTHQ values of heavy metals ranged from 6.92 to 42.44 in raw milk of buffalo, highest at wastewater-irrigated agricultural farms and lowest at tube well water site, indicating high carcinogenic health risk to exposed population. The multivariate statistical analysis revealed that contaminated fodder like Maize and Brassica plants grown with wastewater and contaminated soil are common sources contributing the heavy metal contamination in raw milk. It invites attention of government to remediate the situation to avoid the potential risks to public health from resulting food chain contamination.
Mostrar más [+] Menos [-]17-α-Ethinylestradiol modulates endocrine and behavioral responses to stress in zebrafish Texto completo
2020
Fenske, Lurian | Concato, Ani Carla | Vanin, Ana Paula | Tamagno, Wagner Antonio | de Oliveira Sofiatti, Jéssica Reis | Treichel, Helen | da Rosa, João Gabriel Santos | Barcellos, Leonardo José Gil | Kaizer, Rosilene R.
The synthetic estrogen, 17-α-ethinylestradiol (EE2), present in contraceptive pills, is an endocrine-disrupting chemical (EDC) that can be found in the aquatic environment. We examined the impacts of EE2 on zebrafish behavioral and physiological responses through the novel tank test (NTT), which measures anxiety-like behavior; the mirror-induced aggression (MIA) test, which measures aggressiveness; and the social preference test (SPT), which measures social cohesion. The steroid hormone levels were also measured. Here, we show that exposure to EE2 impairs stress responses by regulating the levels of specific hormones and eliciting an anxiolytic response, increasing aggression, and reducing social preference in zebrafish. In nature, these changes in behavior compromise reproduction and anti-predator behaviors, which, in turn, affects species survival. The maintenance of an intact behavioral repertoire in zebrafish is essential for their survival. Thus, our results point to the danger of environmental contamination with EE2 as it may alter the dynamics of the prey–predator relationship.
Mostrar más [+] Menos [-]C, N, and P stoichiometry and their interaction with different plant communities and soils in subtropical riparian wetlands Texto completo
2020
Yu, Meng-Fei | Tao, Yongxia | Liu, Wenzhi | Xing, Wei | Liu, Guihua | Wang, Lai | Ma, Lin
Ecological stoichiometry represents the balance of nutrient elements under ecological interactions, which are crucial for biogeochemical cycles in ecosystems. Little is known about carbon (C), nitrogen (N), and phosphorus (P) ecological stoichiometry in aboveground biomass, roots, and soil, especially in the subtropical riparian wetlands. Here, eight dominate plant communities in riparian wetlands were chosen, and C, N, and P contents, and C:N:P ratios of aboveground biomass, roots, and soil were investigated. The results demonstrated that plant community had remarkable effects on the C:N:P stoichiometry in aboveground biomass, roots, and soil, which varied widely. C, N, and P concentrations in aboveground biomass were mostly higher than that in roots, while no significant difference was detected in C:N:P ratios. Moreover, there were higher soil C, N, and P contents in Cannabis indica plant communities; while lower soil N:P ratios suggested that riparian wetlands were more susceptible to N limitation, rather than P. Pearson correlation analysis and redundancy analysis (RDA) showed that there were strong associations among C, N, and P contents, and C:N:P ratios in aboveground biomass, roots, and soil, indicating that C, N, and P ecological stoichiometry of aboveground biomass were regulated by soil C, N, and P contents through the roots. In addition, the contents of C and N, and N and P exhibited a strong relationship according to linear regression. These findings suggested that the interactions among the C, N, and P stoichiometry were existed in the plant-soil system.
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