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Combining habitat area and fragmentation change for ecological disturbance assessment in Jiangsu Province, China Texte intégral
2020
Jin, Zhifeng | Wang, Jing | Kong, Xuesong
Understanding where and how human land use causes ecological consequences is essential for habitat conservation. However, the assessment of the ecological disturbance caused by human land use is usually shaped by the area change in ecological land. The comprehensive evaluation of ecological disturbance based on the losses and gains of ecological patches is neglected. This paper analyzed the land use change between agricultural land, construction land, and ecological land from 1995 to 2015 in Jiangsu Province of eastern China. The ecological disturbance was quantificationally evaluated by a proposed index that considered both the changes of habitat area and fragmentation caused by the losses and gains of ecological landscape patches. The findings showed that there was a slight increase in area of ecological land in Jiangsu Province; however, ecological fragmentation was becoming severe with the growth of human land use, which, in turn, resulted in increased ecological disturbance. The losses and gains in the area and fragmentation of ecological land were comprehensively reflected using the proposed ecological disturbance index. Negative ecological disturbance was more likely to be observed at the edge of the city centers, ecologically sensitive areas, and counties with low area ratios of ecological land. Ecological governance policies should be formulated and implemented based on quantity, quality, and spatial relationships between human land use and ecological disturbance.
Afficher plus [+] Moins [-]Potential anti-inflammatory and anti-apoptotic effect of Coccinia grandis plant extract in LPS stimulated-THP-1 cells Texte intégral
2020
Albrahim, Tarfa | Alnasser, Moonerah M. | Al-Anazi, Mashael R. | ALKahtani, Muneera D. | Alkahtani, Saad | Al-Qahtani, Ahmed A.
Coccinia grandis (C. grandis) L is an Indian medicinal plant from the Cucurbitaceae family whose extracts possess anti-oxidant, anti-infective, and anti-inflammatory properties. The objective of the present study was to probe the potential immunomodulatory of C. grandis crude extract on different pathways in THP-1 cells as probed by changes in expression of several proteins. THP-1 cells were differentiated into macrophages after treatment with phorbol-12-myristate 13-acetate, followed by exposure to lipopolysaccharide (LPS) with or without 50 or 100 μg/ml of C. grandis extract. Treatment of the cells with the extract significantly downregulated the expression and release of pro-inflammatory cytokines (IL-6, IL-1β, CCL2, CCL22, CXCL10/IP-10, CX3CL1 and CXCL8/IL-8), proteins (ERK5, BAX, BCL2, Cyclin D, ERK1, NF-κB, P-IκBα,P- NF-κB and P-p38) and molecular signaling pathways (NF-κB, p38 MAPK, ERK1/2 and IL-6/JAK/STAT3 signaling cascades). This study is the first to highlight the ability of C. grandis extract to modulate several pathways, including proliferation, the expression of inflammatory cytokines, phagocytosis, migration properties and apoptosis, in human monocytic THP-1 cells.
Afficher plus [+] Moins [-]The impact of technology-environmental innovation on CO2 emissions in China’s transportation sector Texte intégral
2020
Chen, Fang | Zhao, Tao | Liao, Zhiming
Along with the development of urbanization and informationization, an increasing attention has been attracted to CO₂ emissions of China’s transportation sector and its influencing factors. Such researches mainly utilize single indicator or two indicators to represent technology process. This research aims to verify the influence of technology-environmental innovation indicator system on CO₂ emissions of China’s transportation sector by decoupling elasticity and econometric model. We firstly recognize the decoupling status of CO₂ emissions of China’s transportation sector from social economic development and aggregate China’s 30 provinces into two groups according to the varied decoupling status, namely expansive coupling and weak decoupling groups. Then, we develop a relatively comprehensive technology-environmental innovation indicator system to measure technology process. Finally, the multi-region comparison of emission drivers is studied among overall China and the two groups. The result shows that the decoupling elasticity of China’s transportation has experienced an evolution process trending to desired development status and all the provinces have experienced expansive coupling and weak decoupling from 2001 to 2016, except Qinghai. Innovation performance indicators exert most important influence on the CO₂ emissions of transportation sector. Finally, the influences of technology-environmental innovation indicators are similar across groups with different magnitude, suggesting that common but differentiated strategies should be provided when mitigating CO₂ emissions with technology process. Graphical abstract
Afficher plus [+] Moins [-]Dithiothreitol-based oxidative potential for airborne particulate matter: an estimation of the associated uncertainty Texte intégral
2020
Molina, Carolina | Andrade, Catalina | Manzano, Carlos A. | Richard Toro, A. | Verma, Vishal | Leiva-Guzmán, Manuel A.
Oxidative stress is considered as one of the main mechanisms by which airborne particles produce adverse health effects. Several methods to estimate the oxidative potential (OP) of particulate matter (PM) have been proposed. Among them, the dithiothreitol (DTT) assay has gained popularity due to its simplicity and overall low implementation cost. Usually, the estimations of OPᴰᵀᵀ are based on n-replicates of a set of samples and their associated standard deviation. However, interlaboratory comparisons of OPᴰᵀᵀ can be difficult and lead to misinterpretations. This work presents an estimation of the total uncertainty for the OPᴰᵀᵀ measurement of PM₁₀ and PM₂.₅ samples collected in Santiago (Chile), based on recommendations by the Joint Committee for Guides in Metrology and Eurachem. The expanded uncertainty expressed as a percentage of the mass-normalized OPᴰᵀᵀ measurements was 18.0% and 16.3% for PM₁₀ and PM₂.₅ samples respectively. The dominating contributor to the total uncertainty was identified (i.e., DTT consumption rate, related to the regression and repeatability of experimental data), while the volumetric operations (i.e., pipettes) were also important. The results showed that, although the OP measured following the DTT assay has been successfully used to estimate the potential health impacts of airborne PM, uncertainty estimations must be considered before interpreting the results.
Afficher plus [+] Moins [-]Cadmium tolerance and detoxification in Myriophyllum aquaticum: physiological responses, chemical forms, and subcellular distribution Texte intégral
2020
Li, Guoxin | Li, Qingsong | Wang, Lei | Zhang, Dandan
Submerged macrophytes have been found to be promising in removing cadmium (Cd) from aquatic ecosystems; however, the mechanism of Cd detoxification in these plants is still poorly understood. In the present study, Cd chemical forms and subcellular distributing behaviors in Myriophyllum aquaticum and the physiological mechanism underlying M. aquaticum in response to Cd stress were explored. During the study, M. aquaticum was grown in a hydroponic system and was treated under different concentrations of Cd (0, 0.01, 0.05, 0.25, and 1.25 mg/L) for 14 days. The differential centrifugation suggested that most Cd was split in the soluble fraction (57.40–66.25%) and bound to the cell wall (24.92–38.57%). Furthermore, Cd in M. aquaticum was primarily present in NaCl-extractable Cd (51.76–91.15% in leaves and 58.71–84.76% in stems), followed by acetic acid–extractable Cd (5.17–22.42% in leaves and 9.54–16.56% in stems) and HCl-extractable Cd (0.80–12.23% in leaves and 3.56–18.87% in stems). The malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) concentrations in M. aquaticum were noticeably increased under each Cd concentration. The activities of catalase (CAT), guaiacol peroxidase (POD), and superoxide dismutase (SOD) in leaves were initially increased under relatively low concentrations of Cd but were decreased further with the increasing concentrations of Cd. The ascorbate (AsA), glutathione (GSH), and nitric oxide (NO) concentrations in stems increased with increasing Cd concentrations. Taken together, our results indicate that M. aquaticum can be used successfully for phytoremediation of Cd-contaminated water, and the detoxification mechanisms in M. aquaticum include enzymatic and non-enzymatic antioxidants, subcellular partitioning, and the formation of different chemical forms of Cd.
Afficher plus [+] Moins [-]Bioaccumulation and toxic effects of penconazole in earthworms (Eisenia fetida) following soil exposure Texte intégral
2020
Li, Ruisheng | Meng, Zhiyuan | Sun, Wei | Wu, Ruoyue | Jia, Ming | Yan, Sen | Tian, Sinuo | Zhu, Wentao | Zhou, Zhiqiang
As an agricultural fungicide, penconazole (PEN) is widely used and has adverse effects on various organisms. In order to evaluate the ecological safety risks of PEN, the bioaccumulation and toxic effects of PEN in earthworms were studied. Specifically, the results show that the biota-sediment accumulation factor (BSAF) of PEN in earthworms reaches its maximum within 1 day, and then decreases slowly. It reached its lowest value after 14 days of PEN exposure and then rose again. In addition, oxidative stress and metabolic disorder of the earthworm with PEN exposure were assessed. After PEN exposure, the related indicators of oxidative stress involved in the activities of SOD and CAT and the contents of GSH and MDA all changed significantly in earthworms. Moreover, metabolomics analysis of earthworms showed disturbed metabolic profiles following PEN exposure. Respectively, PEN exposure significantly altered the relative abundances of 14 metabolites in earthworms. In general, exposure to PEN caused oxidative stress and metabolic profile disorders of earthworms. The results of this study will be helpful for further evaluation of soil ecological security of PEN.
Afficher plus [+] Moins [-]Removal of heavy metals in aquatic environment by graphene oxide composites: a review Texte intégral
2020
Zhang, Quan | Hou, Qinxuan | Huang, Guanxing | Fan, Qi
As the most important graphene derivate, graphene oxide (GO) is a high-efficient adsorbent for the removal of heavy metals in aquatic environment due to its abundant oxygen functional groups, enormous specific area, and strong hydrophilia. However, there are some drawbacks, such as easily aggregating and difficult separation, restricting the environmental application of GO. GO is not a suitable adsorbent by itself. Hence, some materials were used to synthesize GO composites, and GO composites are commonly characterized by high adsorption capacity to overcome the above drawbacks. This review discusses five main GO composites—GO–chitosan, GO–alginate, GO–SiO₂, NZVI–rGO, and magnetic GO composites—and summarizes the synthesis methods of GO composites and its application for the removal of heavy metals in aquatic environments. The influencing factors, adsorption capacities, and mechanisms related to the removal of heavy metals by GO composites are highlighted. Lastly, the application potentials and challenges of GO composites for aqueous environmental remediation are discussed. Graphical abstract
Afficher plus [+] Moins [-]Enhanced solubilization and reductive degradation of 2,2′,4,4′- tretrabromodiphenyl ether by PAC-Pd/Fe nanoparticles in the presence of surfactant Texte intégral
2020
Li, Haijie | Huang, Guofu | Wang, Mianmian
2,2′,4,4′-Tretrabromodiphenyl ether (BDE47) is known as a typical polybrominated diphenyl ethers (PBDEs) due to its high environmental abundance, ecological toxicity, and bioaccumulation. In this study, the influences of three typical surfactants (CTAB, SDS, and TX-100) on BDE47 solubilization and degradation by the polyanionic cellulose–stabilized Pd/Fe (PAC-Pd/Fe) nanoparticles were investigated. The results showed that BDE47 solubilities increased linearly when surfactant concentrations were above their critical micelle concentrations (CMCs), and the solubilization capacities of surfactants for BDE47 followed the order of TX-100 > CTAB > SDS. The appropriate dosages of surfactants were favorable for BDE47 degradation due to enhancing solubilization and accelerating mass transfer, while excessive surfactants inhibited BDE47 degradation due to excessive and thicker micelles formed, but still higher than no surfactant. The influences of various factors (PAC-Pd/Fe nanoparticle dosage, solution pH, and temperature) on BDE47 degradation in TX-100 solution were also tested. The results showed that BDE47 degradation followed the pseudo first-order kinetics model. The degradation rates of BDE47 increased as PAC-Pd/Fe nanoparticle dosage and temperature increased. Weak acidic condition (pH 5.5) was favorable for BDE47 degradation with 96.8% BDE47 was removed within 7.5 min, while alkaline condition (9.0) was not conducive to the degradation of BDE47. The degradation of BDE47 by PAC-Pd/Fe nanoparticles was a catalytic reductive debromination process via active H-species attack, wherein the sequential debromination was the dominant reaction. This study suggests that in the presence of moderate surfactant, PAC-Pd/Fe nanoparticles may be potentially employed to eliminate BDE47 in contaminated water.
Afficher plus [+] Moins [-]Whether China made efforts to decouple economic growth from CO2 emissions?-Production vs consumption perspective Texte intégral
2020
Yang, Lin | Yang, Yuantao | Lv, Haodong | Wang, Dong
Decoupling analysis is able to reveal the linkage between economic growth and environmental pressure. However, traditional studies mostly concentrate on production-based decoupling analysis and ignore the pressure emerging from supply chains to satisfy the final consumption. Through a comprehensive framework integrating input–output analysis, decomposition methods, and the Tapio index, this work may be considered the first attempt to explore whether China made efforts to decouple economic growth from CO₂ emissions from production-based and consumption-based perspectives simultaneously. We found that (1) CO₂ emissions in China expanded by around 1.6-fold during 2002–2015, of which Production and supply of electricity and heat and Construction contributed most to the production-based emissions (PBE) and consumption-based emissions (CBE), respectively; (2) Three-quarters of sectors presented weak decoupling or strong decoupling under both PBE and CBE perspectives, and Textile was the only sector achieving strong decoupling under both perspectives; (3) All sectors have made efforts to decouple economic growth from CO₂ emissions under PBE perspective, while several sectors failed under CBE perspective. Overall, the decoupling status for PBE was better than that for CBE during the study period. Our results are able to provide targeted and effective references for allocating decoupling responsibilities between producers and final consumers more adequately and reasonably.
Afficher plus [+] Moins [-]Effects of some industrial and organic wastes application on growth and heavy metal uptake by tomato (Lycopersicum esculentum) grown in a greenhouse condition Texte intégral
2020
Taghipour, Marzieh | Jalali, Mohsen
In this study, pot experiments were conducted to determine the effects of industrial solid wastes (ISWs) (ceramic, stone, and sugar factory wastes) and organic wastes (rice husk and wheat straw) on growth and heavy metals uptake by tomato (Lycopersicum esculentum) plants. The soil was treated with 10% of ISWs and 5% of organic wastes. The fractionation of heavy metals also has been studied in all treated soils. It was observed that the addition of ISWs in soil increased heavy metal contents in all fractions. The addition of organic wastes to control and treated soils decreased exchangeable fraction and increased organic matter and residual fractions. Following the ceramic factory and stone cutting waste addition, tomato yield significantly decreased as compared to control soil. The application of ISWs caused an increase in heavy metal contents of tomato plants. In control and ISWs-treated soils, dry matter yield of tomato grown in the presence of wheat straw was significantly restricted, while the application of rice husk increased tomato shoot and root dry weight. Results of experiments indicated that the application of both organic wastes significantly decreased heavy metal uptake by tomato plants. The investigation of health risk index (HRI) values indicated that in these industrial areas, potential health risk by intake of heavy metals from tomato for both adults and children generally assumed to be safe. The values of HRI were lesser when rice husk was applied to the soil. In general, these results highlighted that the application of rice husk in soils contaminated with ISWs increased the growth and yield of tomato and reduced the heavy metal toxicity for tomato consumption in contaminated soils.
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