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Uptake and detoxification of trace metals in estuarine crabs: insights into the role of metallothioneins 全文
2020
Truchet, Daniela María | Buzzi, Natalia Sol | Simonetti, Pía | Marcovecchio, Jorge Eduardo
Uptake and detoxification of trace metals in estuarine crabs: insights into the role of metallothioneins 全文
2020
Truchet, Daniela María | Buzzi, Natalia Sol | Simonetti, Pía | Marcovecchio, Jorge Eduardo
The detoxification process of trace metals in the estuarine burrowing crab Neohelice granulata, after previously being exposed to anthropogenic pressures in the field, is described for the first time. The objectives of this study were (a) to assess the metal content (Cd, Cu, Pb, Zn, Mn, Ni, Cr, Fe) in the sediments and the uptake of these elements in the hepatopancreas of N. granulata; (b) to quantify trace metal concentrations in the hepatopancreas before and after the detoxification experiment; and (c) to relate this information to metallothionein (MT) induction or reversibility. The detoxification assay was performed for 25 days with artificial seawater under controlled conditions in a culture chamber. The results showed higher uptake and bioaccumulation of Zn and Cu from the sediments, and the hepatopancreas exhibited increased levels of Zn and lower concentrations of the rest of the metals and MTs after the assay, mainly Fe and Mn that were significantly lower. We conclude that trace metals could be translocated to and accumulated in the hepatopancreas, the main metabolic organ, and then eliminated under controlled conditions with corresponding reversibility of MTs. Graphical abstract
显示更多 [+] 显示较少 [-]Uptake and detoxification of trace metals in estuarine crabs: insights into the role of metallothioneins 全文
2020
Truchet, Daniela María | Buzzi, Natalia Sol | Simonetti, Pia | Marcovecchio, Jorge Eduardo
The detoxification process of trace metals in the estuarine burrowing crab Neohelice granulata, after previously being exposed to anthropogenic pressures in the field, is described for the first time. The objectives of this study were (a) to assess the metal content (Cd, Cu, Pb, Zn, Mn, Ni, Cr, Fe) in the sediments and the uptake of these elements in the hepatopancreas of N. granulata; (b) to quantify trace metal concentrations in the hepatopancreas before and after the detoxification experiment; and (c) to relate this information to metallothionein (MT) induction or reversibility. The detoxification assay was performed for 25 days with artificial seawater under controlled conditions in a culture chamber. The results showed higher uptake and bioaccumulation of Zn and Cu from the sediments, and the hepatopancreas exhibited increased levels of Zn and lower concentrations of the rest of the metals and MTs after the assay, mainly Fe and Mn that were significantly lower. We conclude that trace metals could be translocated to and accumulated in the hepatopancreas, the main metabolic organ, and then eliminated under controlled conditions with corresponding reversibility of MTs. | Fil: Truchet, Daniela María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; Argentina | Fil: Buzzi, Natalia Sol. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; Argentina | Fil: Simonetti, Pia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina | Fil: Marcovecchio, Jorge Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina. Universidad FASTA "Santo Tomas de Aquino"; Argentina. Universidad Tecnológica Nacional. Facultad Regional Bahía Blanca; Argentina
显示更多 [+] 显示较少 [-]Copper-induced oxidative stress and biomarkers in the postlarvae of Penaeus indicus 全文
2020
Thatipaka, Samuel David Raj | Paila, Rupa Vani | Polaki, Suman
The objective of the present research is to study the levels of reactive oxygen species (ROS) and protein carbonyl (PC) and the functional protein levels of metallothioneins (MT) in Penaeus indicus postlarvae (PL) upon sublethal copper exposure and to determine the biomarkers. The PL were exposed to sublethal copper of 0.164 ppm. The experiments were carried out in the laboratory over a period of 30 days with sampling intervals of 24, 48, and 96 h and 10, 20, and 30 days. The present study confirms that high oxidative stress can be induced from 24 h onwards upon sublethal exposure to copper in P. indicus PL. This is evident from the increasing levels of ROS in the exposed PL during both short-term and long-term exposures to sublethal copper. Since variability in metallothionein levels from 24 h through 30 days of experimental period was observed, metallothioneins cannot be regarded as a good biomarker as far as copper toxicity with respect to P. indicus PL is concerned. The effect of copper on protein carbonyl seems to be very rapid and consistent. The results suggest that protein carbonyl in P. indicus PL is significantly induced in a time-dependent manner upon copper exposure even at sublethal dose, and it seems reasonable to support that protein carbonyl could be used as a biomarker to copper toxicity.
显示更多 [+] 显示较少 [-]Can environmental innovation benefit from outward foreign direct investment to developed countries? Evidence from Chinese manufacturing enterprises 全文
2020
Bai, Yu | Qian, Qianqian | Jiao, Jianling | Li, Lanlan | Li, Fangyi | Yang, Ranran
Environmental innovation is an important way to low-carbon economic growth. Outward foreign direct investment (OFDI) can produce reverse technology transfer to promote innovation. This study aims to examine whether OFDI to developed countries can transfer reverse green technology and promote the environmental innovation of manufacturing enterprises in emerging economies (EEs). Based on the technology gap theory, resource bricolage theory, resource-based view, and Potter hypothesis, this study constructs a conceptual model including the direct effect of OFDI on environmental innovation and the moderating effects of the knowledge level of the host country, multinational strategy, absorptive capacity, and environmental regulation. To verify the model, we also use a panel dataset of 424 Chinese manufacturing enterprises during 2010–2017, and the results indicate that OFDI to developed countries can produce reverse green technology transfer and promote parent companies’ environmental innovation. The knowledge level of the host country and multinational strategy can further improve the impacts on environmental product innovation. However, absorptive capacity and environmental regulation in EEs do not play a significant moderating role. Consequently, this study expands the application scope of existing theories and enriches the theoretical basis of the relationship between OFDI and environmental innovation.
显示更多 [+] 显示较少 [-]Proximate analysis and fatty acid of Corbicula fluminea (C. fluminea) tissue in Kelantan, Malaysia 全文
2020
Rak, Aweng Eh | Nasir, Siti Nor Aini Md | Nor, Maryana Mohammad | Han, Dee Koh | Appalasamy, Suganthi | Abdullah, Faizuan | Mohd Ghazi, Rozidaini
Corbicula fluminea (C. fluminea) is one of the mollusc species commonly eaten as a popular snack in Kelantan, Malaysia. This species contributes to the local economic activity. However, the handling process of C. fluminea at different processing stages (raw, smoke and selling stages) is believed to have affected the nutritional value in their soft tissue. Hence, this study aims to provide information about the chemical content (moisture, crude fat, ash, crude protein and carbohydrate) of C. fluminea and fatty acid of smoked C. fluminea at different processing stages. Samples were collected from Pasir Mas and Tumpat, Kelantan, Malaysia. The chemical content analysis was carried out based on the Association of Official Analytical Chemists (AOAC) standard procedures. The results have indicated that moisture (80.93 ± 0.37%) and crude fat (10.82 ± 0.21%) in C. fluminea were significantly higher (p < 0.05) at the raw stage. On the other hand, the ash (2.09 ± 0.03%) and crude protein (9.45 ± 0.42%) were significantly higher (p < 0.05) at smoked stage. Meanwhile, carbohydrate (3.39 ± 0.49%) was significantly higher (p < 0.05) at the selling stage. The fatty acid percentage of smoked C. fluminea indicates that the total saturated fatty acid (SFA) content was higher than the total of both monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA). The obtained data indicates that the composition percentage of omega-6 (n-6) in PUFA is significantly greater than omega-3 (n-3). The n-6/n-3 ratio of smoked C. fluminea is 2.95–3.11 and therefore can be considered as a healthy diet. The findings of this study can improve consumers’ health through sufficient nutrient consumption and also provide economic benefits by increasing sellers’ income in Kelantan.
显示更多 [+] 显示较少 [-]Combined effects of goethite nanoparticles with metallic contaminants and an organophosphorus pesticide on Eisenia andrei 全文
2020
Cáceres-Wenzel, Marcela I. | Fuchs, Julio S. | Bernassani, Florencia N. | Cochón, Adriana C.
The effects of mixtures of nanoparticles (NPs) and other chemicals have been poorly studied in terrestrial invertebrates. In this study, we investigated the effects of binary mixtures of goethite (α-FeOOH) NPs and metallic (Cd and Pb) or organic (chlorpyrifos, CPF) contaminants in Eisenia andrei earthworms. We used the filter paper contact test to evaluate (i) the uptake of NPs in organisms exposed to the mixtures of NPs+Metals and NPs+CPF and (ii) the potential effects of the mixture of NPs+CPF on the CPF-induced inhibition of the biomarker enzymes acetylcholinesterase (AChE) and carboxylesterases (CES). We used the artificial soil test to deepen the study on joint effects of NPs+CPF. All compounds were applied separately and in binary mixtures. In the single exposure treatment, Fe levels decreased significantly in organisms exposed to NPs on filter paper, suggesting systemic effects aimed at eliminating Fe incorporated through NPs. Conversely, earthworms exposed to binary mixtures showed Fe levels similar (NPs+Metals) to or higher (NPs+CPF) than controls. The earthworms single exposed to NPs presented no changes in AChE and CES activities. In the artificial soil test, the only treatment that showed AChE inhibition after 72 h was single CPF exposure, while no significant changes were observed in CES activity. However, after 7-day exposure in artificial soil or 72-h exposure on filter paper, the mixture of NPs+CPF induced a similar degree of AChE and CES inhibition as single CPF exposure. All these suggested that NPs did not produce neurotoxic effects, and that the inhibition of the enzymes’ activities in all cases was due to the presence of the pesticide. On the other hand, the differences in the pattern of Fe accumulation in the earthworms indicate that the presence of other contaminants in the exposure media can modify the uptake and/or the excretion of Fe and evidence the interactions that may be found in binary mixtures of metal oxide NPs and other pre-existing contaminants in the soil ecosystem.
显示更多 [+] 显示较少 [-]Risk of phosphorus losses from Andosols under fertilized pasture 全文
2020
Bajouco, Rui | Pinheiro, Jorge | Pereira, Benilde | Ferreira, Rita | Coutinho, Joao
Fertilization of grassland pastures may be a non-point pollution source in the Azores archipelago, despite the high phosphorus (P) retention of Andosols. To evaluate the risk of P desorption, representative Andosols samples (0–15 cm) were subdivided in five layers and different P pools were measured. The risk of P unloading into waters was assessed by the degree of phosphorus saturation (DPS), and by the P concentration in equilibrium solutions (0.01 M CaCl₂). The higher contents in the superficial layers suggest P accumulation due to pasture overfertilization. The organic P represented about 54% of the total P, with an overall average of 2.66 g Pₜ/kg. Despite being above the agronomic threshold, the soil with the highest average mean values of extractable inorganic P, 77 mg POₗₛₑₙ/kg and and 73.7 mg PAL/kg, is still below environmental thresholds and none of the soils had DPS values above 25%, which is the critical value associated with eutrophication of surface waters. Similarly, all the P concentrations in the equilibrium CaCl₂ solutions were below the critical limits. Therefore, P desorption from these soils did not seem to be the main process responsible for effective waterbodies eutrophication in the Azores. Since mineral fertilizers are applied superficially, the hypothesis of their direct runoff during rainfall events, even before their complete dissolution and interaction with the soil matrix, must be considered. Consequently, P fertilization with deep-banding systems may be the alternative to the interdiction of fertilizers in the most sensitive and hilly areas of the watersheds.
显示更多 [+] 显示较少 [-]Evaluation of urban comprehensive carrying capacity: case study of the Beijing–Tianjin–Hebei urban agglomeration, China 全文
2020
Zhao, Lingling | Li, Jiaying | Shao, Qinglong
An evaluation indexing system based on the theory of coordination was constructed to estimate the urban carrying capacity (UCC) of the Beijing–Tianjin–Hebei (BTH) region with four subsystems: social, economic, environmental, and transportation. This indexing system revealed the interactions between “supply” and “demand.” The improved entropy method was adopted to calculate the weight of 17 indicators and evaluate the comprehensive UCC of 13 cities in the BTH region using data covering the period 1990–2018. The results showed that two cities, Tangshan (UCC of − 0.0021) and Handan (UCC of − 0.0009), were “overloaded” in 2018, while the other 11 cities were “loadable.” The social and transportation subsystems played the most crucial roles in the evaluation. Based on the results, Baoding achieved the highest UCC, while that of Tangshan was the lowest. The results could play a significant role in decision-making relating to the sustainable development of the BTH region. Three policy implications are proposed based on these findings: (i) the efficiency of resource utilization and scientific allocation should be enhanced and industrial optimization and upgrading should be promoted, (ii) the coordinated development of urbanization and environment in the region should be improved, and (iii) the integration of traffic decongestion measures should be faster, and industrial docking systems should be enhanced.
显示更多 [+] 显示较少 [-]Risk management activities for oil and gas producers and the impact on firm value 全文
2020
Yildiz Savas, Eren | Kapusuzoglu, Ayhan
This study analyses whether hedging activities of oil and gas firms have a significant effect on the performance of the companies. The performance of companies is proxied by Tobin’s Q and panel regression models are built to estimate the coefficients for firm value and derivative use. The speculative use of derivatives is eliminated in models by the regulations under IFRS and GAAP. The results give critical information regarding asymmetric information and signalling effect. Since the coefficient of derivatives use is negative, it shows the critical meaning of disclosures on the financial healthiness. If companies are publishing high level of hedging activities, it might be a warning for investors to avoid investing at that company. This study also seeks for explanation behind firms’ hedging decisions. To our knowledge, it is among the first studies with a wide range of region and data.
显示更多 [+] 显示较少 [-]Trace elements and oxidative stress in the Ark shell Arca noae from a Mediterranean coastal lagoon (Bizerte lagoon, Tunisia): are there health risks associated with their consumption? 全文
2020
Ghribi, Feriel | Richir, Jonathan | Bejaoui, Safa | Boussoufa, Dhouha | Marengo, Michel | El Cafsi, M’hamed | Gobert, Sylvie
Trace elements and oxidative stress in the Ark shell Arca noae from a Mediterranean coastal lagoon (Bizerte lagoon, Tunisia): are there health risks associated with their consumption? 全文
2020
Ghribi, Feriel | Richir, Jonathan | Bejaoui, Safa | Boussoufa, Dhouha | Marengo, Michel | El Cafsi, M’hamed | Gobert, Sylvie
The current study examined the concentrations of ten trace elements (TE) (nickel, chromium, cadmium, iron, zinc, manganese, aluminum, copper, selenium and lead) in the edible tissue of the Ark shell Arca noae (L. 1758) from a Mediterranean coastal lagoon, the Bizerte lagoon during 2013–2014. The analysis of several redox status biomarkers, metallothioneins (MTs), malondialdehyde (MDA), glutathione peroxidase (GPx), reduced glutathione (GSH) and acetylcholinesterase (AChE), was monitored as a response to TE bioaccumulation and environmental parameters variability. Significant differences (p < 0.05) were observed between mean seasonal TE concentrations in A. noae soft tissue. The highest TE concentrations in A. noae soft tissues were recorded during summer, which coincided with the increase of body dry weight (BDW) and the gonad index (GI). During this season, biomarker responses were enhanced, revealing significant increases of MTs, MDA and GSH levels as well as GPx activity in A. noae tissues, while a decrease of AChE activity was observed. The levels of TE analyzed in A. noae and several parameters used to assess the potential human risk (estimated weekly intake, target hazard quotient and target hazard risk) were lower than the permissible limits for safe seafood consumption. Consequently, this shellfish can be considered safe for human consumption. This preliminary study presents prospects for the valorization of this seafood product in Tunisia’s food sector. It also gives basal information for future environmental assessment studies in which A. noae could be used as early warning tools in the field of biomonitoring programs and confirms the usefulness of biomarkers to monitor the health status of aquatic organisms.
显示更多 [+] 显示较少 [-]Trace elements and oxidative stress in the Ark shell Arca noae from a Mediterranean coastal lagoon (Bizerte lagoon, Tunisia): are there health risks associated with their consumption? 全文
2020
Ghribi, Feriel | Richir, Jonathan | Bejaoui, Safa | Boussoufa, Dhouha | Marengo, Michel | El Cafsi, M'hamed | Gobert, Sylvie | FOCUS - Freshwater and OCeanic science Unit of reSearch - ULiège
peer reviewed | The current study examined the concentrations of ten trace elements (TE) (nickel, chromium, cadmium, iron, zinc, manganese, aluminum, copper, selenium and lead) in the edible tissue of the Ark shell Arca noae (L. 1758) from a Mediterranean coastal lagoon, the Bizerte lagoon during 2013–2014. The analysis of several redox status biomarkers, metallothioneins (MTs), malondialdehyde (MDA), glutathione peroxidase (GPx), reduced glutathione (GSH) and acetylcholinesterase (AChE), was monitored as a response to TE bioaccumulation and environmental parameters variability. Significant differences (p < 0.05) were observed between mean seasonal TE concentrations in A. noae soft tissue. The highest TE concentrations in A. noae soft tissues were recorded during summer, which coincided with the increase of body dry weight (BDW) and the gonad index (GI). During this season, biomarker responses were enhanced, revealing significant increases of MTs, MDA and GSH levels as well as GPx activity in A. noae tissues, while a decrease of AChE activity was observed. The levels of TE analyzed in A. noae and several parameters used to assess the potential human risk (estimated weekly intake, target hazard quotient and target hazard risk) were lower than the permissible limits for safe seafood consumption. Consequently, this shellfish can be considered safe for human consumption. This preliminary study presents prospects for the valorization of this seafood product in Tunisia’s food sector. It also gives basal information for future environmental assessment studies in which A. noae could be used as early warning tools in the field of biomonitoring programs and confirms the usefulness of biomarkers to monitor the health status of aquatic organisms.
显示更多 [+] 显示较少 [-]The impact of hot metal temperature on CO2 emissions from basic oxygen converter 全文
2020
Díaz, José | Fernandez, Francisco Javier
Recycled steel is a key material for sustainable development. However, not all steel demand can be met by recycling, and therefore, new metallic iron must be introduced in the global cycle. The transformation of iron oxides into steel requires carbon which is oxidized into CO₂. This paper focuses on the basic oxygen furnace (BOF) where molten iron is converted into liquid steel. In order to assess the effect of molten iron temperature on CO₂ emissions, the process has been modelled using mass and energy balances. Model results show that, for a typical converter charge, a slight increase of 10 °C can lead to a direct reduction of 0.006 t of CO₂ per ton of liquid steel. A total variation of 0.17 t of CO₂ per ton of liquid steel is found depending on plant strategy and process constraints. Finally, different actuation levers for carbon mitigation are assessed. It can be concluded that operation and modelling improvements should be jointly addressed to exploit their full potential for carbon footprint reduction.
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