خيارات البحث
النتائج 4391 - 4400 من 7,292
Influence of light-irradiated Noccaea caerulescens on the characteristics of dissolved organic matter in its rhizospheric soil during phytoremediation النص الكامل
2022
Niu, Yao | Wang, Zhansheng | Wang, Hanfei | Yang, Xiaoying | Cao, Min | Luo, Jie
It has been observed that suitable light irradiation can improve the phytoremediation efficiency of various plants by enhancing their growth rate and metal uptake capacity. However, the mechanisms underlying the effects of light irradiation on metal mobilization and translocation in soils have rarely been reported. This experiment was conducted to evaluate the variation in dissolved organic matter (DOM) in the rhizosphere of Noccaea caerulescens (formerly Thlaspi caerulescens J. & C. Presl) when irradiated with different combinations of red (0, 25, 50, 90, and 100% red) and blue light. N. caerulescens was induced to secrete significantly more DOM, relative to the control, into its rhizosphere after being irradiated with pure red light and other red light combinations; this increased the bioavailability of soil Cd. Moreover, the concentrations and proportions of the hydrophilic DOM fractions, particularly hydrophilic acid, which exhibited a high affinity for Cd, increased with increasing ratios of the red light. Furthermore, DOM secreted because of the light irradiation treatments exhibited a significantly higher Cd extraction ability compared with that of the untreated control; this consequently increased the Cd uptake capacity of N. caerulescens. The results demonstrated that the secretion of more DOM, particularly hydrophilic acid, plays a pivotal role in improving the phytoremediation efficiency of N. caerulescens.
اظهر المزيد [+] اقل [-]Do foreign direct investments influence environmental degradation? Evidence from a panel autoregressive distributed lag model approach to low-, lower-middle-, upper-middle-, and high-income countries النص الكامل
2022
Baskurt, Burcu Bahceci | Celik, Saban | Aktan, Bora
The main aim of the present study is to examine the possible nonlinear relations between foreign direct investments and environmental deterioration for subpanels separated according to the income levels of countries by using the classification made by the World Bank. Total energy consumption, economic growth, and renewable energy share are also considered as determinants of environmental deterioration in the model. Cross-sectional dependence is observed; hence, appropriate panel data unit root and cointegration tests are utilized for which results pointed out mixed integration order. Pooled mean group (PMG) estimator panel auto-regressive distributed lag (ARDL, hereafter) approach is adapted to observe short- and long-run relationships between the variables. Long-run results supported the pollution haven hypothesis as foreign direct investments caused an increase in ecological footprint. Findings are sensitive to different income levels of the subpanels of countries. This empirical study suggests tailored policymaking for every income level subpanel to ensure sustainable development.
اظهر المزيد [+] اقل [-]Valorization of waste chicken skin for conjugated linoleic acid (CLA) production: optimization using response surface methodology النص الكامل
2022
Var, Ganime Beyzanur | Özer, Cem Okan
The valorization of waste chicken skin fat (WCSF) for conjugated linoleic acid (CLA) production was performed by photoisomerization and optimized the process conditions for high CLA production by response surface methodology. The fat extraction yield from waste chicken skin was approximately 52%. The linoleic acid content of the fat obtained from waste chicken skin was increased by the fractionation process approximately 2 times, up to 52%. Optimum iodine amount and processing time for predicted maximum total CLA amount were determined as 0.87% and 116.36 h, respectively. The maximum total CLA amount was predicted and produced experimentally as 32.14% and 29.01%, respectively. Additionally, iodine amount, processing time, and their interaction significantly affected the amount and variety of produced CLA isomers. The results indicated that dominant isomers produced by photoisomerization of WCSF were trans, trans isomers. However, the amount of cis 9, trans 11 and trans 10, cis 12 CLA isomers could be more increased by optimizing the production parameters. The present study indicated that waste chicken skin could be valorized in CLA production by photoisomerization and obtained high value–added product, and also a more economical and faster CLA production could be realized.
اظهر المزيد [+] اقل [-]The effects of air pollution on the lung cancer mortality in rural areas of eastern China: a multi-region study النص الكامل
2022
Zha, Zhenqiu | Li, Guoao | Lv, Yili | Liu, Lingli | He, Jialiu | Xu, Wei | Dai, Dan | Liu, Zhirong | Huang, Fen
Recently, the burden of lung cancer (LC) has attracted global attention. Meanwhile, LC has become the leading cause of death in China. Many studies found a strong link between air pollutants and the risk of LC mortality in some large cities, but the results have been inconsistent, and most studies have only focused on the daily effects of six pollutants in large cities, ignoring their potential cumulative effects. This study was to investigate the weekly effects of six air pollutants (CO, NO₂, O₃, PM₂.₅, PM₁₀, and SO₂) on LC mortality in rural areas of eastern China and to further clarify which population groups were susceptible to air pollution and seasonal trends. First, a generalized additive model was combined with a distributed lag nonlinear model to evaluate the individual impact of air pollution on LC deaths in each area. The random-effect model was then used to pool the associations between air pollutants and LC mortality risk in ten counties or districts. The results showed that six air pollutants had a statistically significant effect on the risk of LC mortality at different lag weeks. The effects of NO₂, PM₁₀, and CO on weekly LC mortality were strongest at a cumulative lag of 1, 0, and 1 week, respectively, the maximum cumulative risk ratio (RR) of 1.37 (95%CI: 1.23 to 1.52), 1.30 (95%CI: 1.15 to 1.46), and 1.30 (95%CI: 1.17 to 1.43), with interquartile concentrations increasing. In summary, air pollution was an important factor in LC mortality, and the effect was stronger on males, the elderly, and during cold season. It was suggested that relevant departments should formulate air pollution management measures for the elderly, males, and in different seasons in rural areas and reduce the burden of lung cancer caused by air pollution.
اظهر المزيد [+] اقل [-]Impacts of nanoplastics on life-history traits of marine rotifer (Brachionus plicatilis) are recovered after being transferred to clean seawater النص الكامل
2022
Wang, Dong | Ru, Shaoguo | Zhang, Wei | Zhang, Zhenzhong | Li, Yuejiao | Zhao, Lingchao | Li, Lianxu | Wang, Jun
With the continuous accumulation of nanoplastics (NPs) in the ocean, it becomes urgent to explore their potential effects on filter-feeding zooplankton. This study exposed marine rotifer (Brachionus plicatilis) to 0, 20, 200, and 2000 μg/L of 70-nm polystyrene NPs (PS NPs) for two generations (F0 − F1), followed by two-generation (F2 − F3) culture in clean seawater, to investigate the impacts on life-history traits. The results showed that NPs were ingested by the rotifers within 10 min and reached a maximum level after 12 h of exposure. NPs were also observed in the feces of F0 and F1 generation rotifers and on the surface of F1 generation eggs. The intake of NPs inhibited microalgae ingestion, decreased body volume, delayed the first spawning time, reduced the total number of eggs and offspring of F0 and F1 generation. Moreover, 2000 μg/L NPs postponed the first hatching time of F0 generation eggs by 2.5 h, and the hatching time of F1 generation eggs was delayed by 7.3 h and 6.8 h under 200 and 2000 μg/L NPs exposure. The first spawning time and the first hatching time of rotifers were still significantly prolonged in the F2 generation, but other life-history traits returned to normal. After being cultured in clean seawater for two generations, all these indicators were recovered to the normal level. Overall, this study demonstrates that the life-history traits of marine rotifers could be flexibly changed with/without PS NPs exposure.
اظهر المزيد [+] اقل [-]A construction strategy for conservative adaptive Kriging surrogate model with application in the optimal design of contaminated groundwater extraction-treatment النص الكامل
2022
Zhang, Shuangsheng | Qiang, Jing | Liu, Hanhu | Zhu, Xueqiang | Lv, Hongli
When the simulation-optimization model to optimize the groundwater extraction-treatment schemes is used, the construction of a surrogate model for the numerical simulation model has become an effective means to overcome the large calculation load of repeatedly calling the numerical model. However, there are still some problems in using the surrogate model, such as large training sample size, low accuracy, and poor optimization results. In this paper, a conservative adaptive Kriging surrogate model (CAKSM) was proposed by coupling the Kriging surrogate model, optimal solution adaptive sampling method (OSAS), and conservative prediction idea. Firstly, an initial Kriging surrogate model (IKSM) was built for the numerical simulation model of groundwater flow and solute transport. Then, the IKSM was coupled with the optimization model to construct the adaptive Kriging surrogate model (AKSM) by using OSAS. A safety margin was added to the AKSM to build the CAKSM. Finally, the simulation-optimization models based on IKSM, AKSM, and CAKSM were solved by the genetic algorithm, respectively. The results showed that the IKSM could well substitute for the simulation model. The AKSM significantly improved the approximation degree between the surrogate model and the simulation model at the optimal solution by supplementing a small number of new samples. CAKSM could effectively constrain the pollutant mass concentrations within the controlled value, improving the reliability of the optimization scheme. The optimal extraction wells based on different surrogate models were all well 5, well 6, and well 9. They were concentrated in the middle and lower reaches of the contaminated plume’s central axis. The sequence for the remediation effects by different surrogate models from high to low was as follows: CAKSM, AKSM, and IKSM. The risk rate of the optimal remediation scheme from the hydraulic conductivity random fields was as high as 12.12%, and the risks were mainly located upstream of the pollution plume’s central axis.
اظهر المزيد [+] اقل [-]Moringa oleifera alcoholic extract protected stomach from bisphenol A–induced gastric ulcer in rats via its anti-oxidant and anti-inflammatory activities النص الكامل
2022
Abo-Elsoud, Reda Abo Elfath Ahmed | Ahmed Mohamed Abdelaziz, Seham | Attia Abd Eldaim, Mabrouk | Hazzaa, Suzan Moustafa
This study evaluated the protective potentials of Moringa oleifera leaf alcoholic extract (MOLE) against bisphenol A (BPA)-induced stomach ulceration and inflammation in rats. Control rats received olive oil. Second group administered MOLE (200 mg/kg bwt) by oral gavage. Third group was given BPA (50 mg/ kg bwt) for 4 weeks. Fourth group administrated BPA and MOLE simultaneously. Fifth group was given MOLE for 4 weeks then administered BPA and MOLE for another 4 weeks. Bisphenol A induced gastric ulceration and decreased the volume of gastric juice, prostaglandin E2 (PGE2), reduced glutathione (GSH) and interleukin 10 (IL-10) contents, superoxide dismutase (SOD) activity, and proliferating cell nuclear antigen (PCNA) protein in stomach tissues, while increased the titratable acidity, malondialdehyde (MDA), tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6) contents, and caspase-3 and NF‑κB proteins in stomach tissue. However, MOLE ameliorated BPA-induced gastric ulceration and significantly increased the volume of gastric juice, PGE2, GSH and IL-10 contents, SOD activity, and PCNA protein while significantly decreased titratable acidity, MDA, TNF-α and IL-6 contents, and of NF‑κB and caspase-3 proteins in gastric tissue. This study indicated that MOLE protected stomach against BPA-induced gastric injury via its anti-oxidant, anti-apoptotic, and anti-inflammatory activities.
اظهر المزيد [+] اقل [-]Pathways to Argentina’s 2050 carbon-neutrality agenda: the roles of renewable energy transition and trade globalization النص الكامل
2022
Murshed, Muntasir | Mahmood, Haider | Ahmad, Paiman | Rehman, Abdul | Alam, Md. Shabbir
The government of Argentina has recently declared its objective of turning the nation carbon–neutral by 2050. Thus, it is essential to identify the relevant factors which can facilitate the attainment of this environmental development target. Against this backdrop, this study aims to evaluate the impacts of renewable electricity output, trade globalization, economic growth, financial development, urbanization, and technological innovation on sectoral carbon dioxide emissions in Argentina during the 1971–2014 period. The findings, overall, suggest that enhancing renewable electricity output share in the total electricity output figure of the nation helps to curb carbon dioxide emissions generated from Argentina’s energy, manufacturing and industry, residential and commercial buildings, and transportation sectors. Contrarily, greater trade globalization is evidenced to boost carbon dioxide emissions in almost all the aforementioned economic sectors. Besides, the findings also validate the existence of the carbon dioxide emission-induced environmental Kuznets curve hypothesis for all four sectors. In addition, financial development and urbanization are also evidenced to exert carbon dioxide emission-stimulating impacts, while technological innovation is witnessed to be necessary for curbing sector-based carbon dioxide emissions in Argentina. Accordingly, to decarbonize the economy, this study recommends the government of Argentina to adopt necessary policies for fostering renewable energy transition within the electricity sector, greening the trade globalization strategies, achieving environmentally sustainable economic growth, developing the financial sector by introducing green financial schemes, planning sustainable urbanization, and financing technological development-oriented projects.
اظهر المزيد [+] اقل [-]The combination of chemical, structural, and functional indicators to evaluate the anthropogenic impacts on agricultural stream ecosystems النص الكامل
2022
Jabiol, Jérémy | Chauvet, Eric | Guérold, François | Bouquerel, Jonathan | Usseglio-Polatera, Philippe | Artigas, Joan | Margoum, Christelle | Le Dréau, Matthieu | Moreira, Aurélie | Mazzella, Nicolas | Gouy, Véronique
Freshwater contamination by pesticides in agricultural landscapes is of increasing concern worldwide, with strong pesticide impacts on biodiversity, ecosystem functions, and ultimately human health (drinking water, fishing). In addition, the excessively large number of substances, as well as their low — and temporally variable — concentrations in water, make the chemical monitoring by grab sampling very demanding and not fully representative of the actual contamination. Tools that integrate temporal variations and that are ecologically relevant are clearly needed to improve the monitoring of freshwater contamination and assess its biological effects. Here, we studied pesticide contamination and its biological impacts in 10 stream sections (sites) belonging to 3 agricultural catchments in France. In each site, we deployed a combination of pesticide integrative samplers, biocenotic indicators based on benthic macroinvertebrates, and functional indicators based on leaf litter decomposition and associated fungal communities. The 3 approaches largely proved complementary: structural and functional indicators did not respond equally to different agricultural impacts such as pesticide contamination (as revealed by integrative samplers), nutrients, or oxygen depletion. Combining chemical, structural, and functional indicators thus seems an excellent strategy to provide a comprehensive picture of agricultural impacts on stream ecosystems.
اظهر المزيد [+] اقل [-]Microplastics as vectors of metals contamination in Mediterranean Sea النص الكامل
2022
Squadrone, Stefania | Pederiva, Sabina | Bezzo, Tabata | Sartor, Rocco Mussat | Battuello, Marco | Nurra, Nicola | Griglione, Alessandra | Brizio, Paola | Abete, Maria Cesarina
Microplastics are contaminants of great concern all over the world. Microplastics constitute pollutants themselves; moreover, other contaminants such as metals are easily absorbed on their plastic surface, becoming bioavailable to marine biota such as zooplankton.We collected marine zooplankton from Mediterranean Sea to investigate trace elements associated with microplastics. Samples were subjected to visual sorting by a stereomicroscope, collected with sterile tweezers, pooled and subjected to sonication, filtration, and drying before being subjected to acid extraction. An ICP-MS was utilized for multi-elemental determination.Aluminum, iron, chromium, zinc, nickel, molybdenum, manganese, lead cobalt, and copper were found at concentrations of mg/kg while arsenic, vanadium, rubidium, and cadmium at level of μg kg⁻¹. Other elements such as silver, beryllium, bismuth, selenium, tin, and thallium were under the limit of quantitation. Lower levels of iron and manganese in samples from Italy were found in comparison to England and Brazil, while aluminum, copper, and zinc registered comparable values. The presence of metals in marine waters is strictly related to sediment lithology and anthropogenic inputs, but plastic plays a key role as vectors for metal ions in the marine system, being able to concentrate metals several order of magnitude higher than in surrounding waters and exerting potential toxicity for living beings after chronic exposure.
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