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Arsenic and/or copper caused inflammatory response via activation of inducible nitric oxide synthase pathway and triggered heat shock protein responses in testis tissues of chicken Texto completo
2018
Shao, Yizhi | Zhao, Hongjing | Wang, Yu | Liu, Juanjuan | Li, Jinglun | Chai, Hongliang | Xing, Mingwei
The aim of this study is to investigate the effects of arsenic (As) and copper (Cu) on the inflammatory response, and the protective roles of heat shock proteins (Hsps) in chicken testes. Seventy-two 1-day-old male Hy-line chickens were treated with 30 mg/kg feed of arsenic trioxide (As₂O₃) and/or 300 mg/kg feed of copper sulfate (CuSO₄) for 4, 8, and 12 weeks. The histological changes, inducible nitric oxide synthase (iNOS) activity, and the expressions of Hsps and inflammatory cytokines were detected. The results showed that slight histology changes were obvious in the testis tissue exposure to treatment groups. The activity and the protein level of iNOS were increased compared to the control group. The mRNA levels of proinflammatory cytokines and inflammatory factors were increased as a whole. However, anti-inflammatory cytokines were inhibited. The mRNA and protein levels of Hsp60, Hsp70, and Hsp90 were upregulated. These results suggested that sub-chronic exposure to As and/or Cu induced testicular poisoning in chickens. Increased Hsps tried to protect chicken testis tissues from tissues damage caused by inflammation. In conclusion, testicular poisoning induced by As and/or Cu caused inflammatory response and heat shock protein response in chicken testis tissues.
Mostrar más [+] Menos [-]The effect of urbanization and industrialization on carbon emissions in Turkey: evidence from ARDL bounds testing procedure Texto completo
2018
Pata, UgurKorkut
This paper examines the dynamic short- and long-term relationship between per capita GDP, per capita energy consumption, financial development, urbanization, industrialization, and per capita carbon dioxide (CO₂) emissions within the framework of the environmental Kuznets curve (EKC) hypothesis for Turkey covering the period from 1974 to 2013. According to the results of the autoregressive distributed lag bounds testing approach, an increase in per capita GDP, per capita energy consumption, financial development, urbanization, and industrialization has a positive effect on per capita CO₂ emissions in the long term, and also the variables other than urbanization increase per capita CO₂ emissions in the short term. In addition, the findings support the validity of the EKC hypothesis for Turkey in the short and long term. However, the turning points obtained from long-term regressions lie outside the sample period. Therefore, as the per capita GDP increases in Turkey, per capita CO₂ emissions continue to increase.
Mostrar más [+] Menos [-]Removal of macro-pollutants in oily wastewater obtained from soil remediation plant using electro-oxidation process Texto completo
2018
Zolfaghari, Mehdi | Drogui, Patrick | Blais, JeanFrançois
Electro-oxidation process by niobium boron-doped diamond (Nb/BDD) electrode was used to treat non-biodegradable oily wastewater provided from soil leachate contaminated by hydrocarbons. Firstly, the diffusion current limit and mass transfer coefficient was experimentally measured (7.1 mA cm⁻² and 14.7 μm s⁻¹, respectively), in order to understand minimum applied current density. Later on, the oxidation kinetic model of each pollutant was investigated in different current densities ranged between 3.8 and 61.5 mA cm⁻². It was observed that direct oxidation was the main removal mechanism of organic and inorganic carbon, while the indirect oxidation in higher current density was responsible for nitrogen oxidation. Hydrocarbon in the form of colloidal particles could be removed by electro-flotation. On the other hand, electro-decomposition on the surface of cathode and precipitation by hydroxyl ions were the utmost removal pathway of metals. According to the initial experiments, operating condition was further optimized by central composite design model in different current density, treatment time, and electrolyte addition, based on the best responses on the specific energy consumption (SEC), chemical oxygen demand (COD), and total organic carbon (TOC) removal efficiency. Unde r optimum operating condition (current density = 23.1 mA cm⁻², time = 120 min, Ti/Pt as a cathode, and Nb/BDD as the anode), electro-oxidation showed the following removal efficiencies: COD (84.6%), TOC (68.2%), oil and grease (99%), color (87.9%), total alkalinity (92%), Nₜₒₜ (18%), NH₄⁺ (31%), Ca (66.4%), Fe (71.1%), Mg (41.4%), Mn (78.1%), Pₜₒₜ (75%), S (67.1%), and Si (19.1%). Graphical abstract Environmental significance statement Soil treatment facilities are rapidly grown throughout the world, especially in North America due to its intense industrialization. High water content soil in humid area like Canada produces significant amount of leachate which is difficult to remove by physical and biological processes. Current treatment facility was modified by applying the electro-chemical oxidation process. The kinetic models of each macro-pollutant included carbon, nitrogen, phosphorous, and metals were developed to investigate their oxidation mechanism (graphical abstract). The efficiency of treatment was monitored in order to optimize the decisive operating parameters of electro-oxidation process. The result of this article could pave the way of future investigation on efficient treatment of variety of oily wastewater.
Mostrar más [+] Menos [-]Identifying and assessing human activity impacts on groundwater quality through hydrogeochemical anomalies and NO3−, NH4+, and COD contamination: a case study of the Liujiang River Basin, Hebei Province, P.R. China Texto completo
2018
Peng, Cong | He, Jiang-Tao | Wang, Man-li | Zhang, Zhen-guo | Wang, Lei
In the face of rapid economic development and increasing human activity, the deterioration of groundwater quality has seriously affected the safety of the groundwater supply in eastern China. Identifying and assessing the impact of human activities is key to finding solutions to this problem. This study is an effort to scientifically and systematically identify and assess the influence of human activities on groundwater based on irregularities in hydrochemical properties and water contamination, which are considered to directly result from anthropogenic activity. The combination of the hydrochemical anomaly identification (HAI) and the contaminant identification (CI) was proposed to identify the influence of human activities on groundwater quality. And the degree of abnormality was quantified by the background threshold value. The principal component analysis (PCA) and land use map were used to verify the reliability of the identification result. The final result show that the strong influence areas mainly distributed in the south of the basin and the affected indicators contained the major elements and NO₃⁻, NH₄⁺, COD. Impacts from anthropogenic activities can be divided into two types: mine drainage that disrupts natural water–rock interaction processes, agricultural cultivation, and sewage emissions that contribute to nitrate pollution.
Mostrar más [+] Menos [-]Residue behavior and risk assessment of imidacloprid applied on greenhouse-cultivated strawberries under different application conditions Texto completo
2018
Cang, Tao | Sun, Caixia | Zhao, Hua | Tang, Tao | Zhang, Changpeng | Yu, Ruixian | Wang, Xinquan | Wang, Qiang | Dai, Fen | Zhao, Xueping
A risk assessment for imidacloprid applied on strawberries under different conditions was performed after residue determination using the quick, cheap, effective, rugged, and safe (QuEChERS) method. The application conditions were varied according to the applied dosage, addition of a plant oil or organosilicon surfactant, water volume, and sprayer type. The degradation dynamics of imidacloprid on strawberries followed first-order kinetics. At applied doses of 30–60 g a.i. ha⁻¹, the half-lives of imidacloprid were 2.89–3.46, 1.98–3.65, and 2.57–2.77 days after application without a surfactant or with a plant oil or organosilicon surfactant, respectively. For water volumes of 112.5, 225, 450, 675, and 900 L ha⁻¹, the half-lives of imidacloprid applied in the presence of the plant oil surfactant were 3.30, 7.70, 5.33, 7.70, and 6.30 days, respectively. The half-lives after application with a knapsack mist duster, electric sprayer, and manual sprayer were 2.16, 5.77, and 7.70 days, respectively. The health risk assessment revealed risk quotients less than 1 in all cases, indicating that the application of imidacloprid poses a low health risk to humans after a pre-harvest interval of 10 days under our application conditions. The risk assessment results can provide reference data for setting a reasonable maximum residue limit for imidacloprid on strawberries in China.
Mostrar más [+] Menos [-]Migration of epoxidized soybean oil from polyvinyl chloride/polyvinylidene chloride food packaging wraps into food simulants Texto completo
2018
Choi, Min Sun | Rehman, Shaheed Ur | Kim, Hyeon | Han, Sang Beom | Lee, Jeongmi | Hong, Jongki | Yoo, Hye Hyun
Epoxidized soybean oil (ESBO) has been used in polyvinyl chloride (PVC)/polyvinylidene chloride (PVDC) food packaging cling film as a plasticizer and stabilizer. The aim of this study was to investigate the migration of ESBO from PVC/PVDC cling film, based on gas chromatography mass spectrometry (GC-MS). The specific migration of ESBO was evaluated using various food simulants (water, 4% acetic acid, 50% ethanol and n-heptane) for PVC and PVDC wrap products. ESBO did not migrate into water and 4% acetic acid for all the tested samples. However, it was released into 50% ethanol and n-heptane in several PVC/PVDC wraps, with maximum migration levels of 38.4 ± 0.7 and 37.4 ± 0.8 μg/mL, respectively. These results demonstrate that ESBO is capable of being released from PVC/PVDC wrap into amphiphilic/oily food and its migration should be regularly monitored.
Mostrar más [+] Menos [-]Nitrogen-doped porous carbon derived from chitosan for the enhanced dehydrochlorination of lindane under mild conditions Texto completo
2018
Yang, Jirui | Shen, Feng | Qiu, Mo | Qi, Xinhua
Dehydrochlorination of lindane is commonly conducted in homogeneous alkaline solutions, possessing a series of problems such as corrosion and poor recyclability. In order to overcome the pervasive problems concerning homogeneous catalysts, heterogeneous catalysts have been increasingly employed in the applications. In this study, nitrogen-doped porous carbons (NPCs) were developed by a simple way in which chitosan and ZnCl₂ were employed as the precursor and activation agent, respectively. NPCs exhibited high surface area (1111–1497 m²/g) and large porosity (0.464–0.621 cm³/g), resulting in a great adsorption affinity to lindane and the by-products. As solid bases, NPCs displayed an enhanced catalytic activity on lindane dehydrochlorination. This was closely related to the amount of pyridinic nitrogen on the pore surface, which could be tuned by the synthesis temperature. The optimal removal efficiency of lindane was up to 99.9% in presence of A800 (a NPC catalyst) at moderate pH (9.0) and mild temperature (45 °C) after incubation for 24 h. The rate constant for A800 suspension was improved by 2–3 orders of magnitude in comparison with that obtained in homogeneous solution at moderate pH (9.0) and mild temperatures (25–45 °C). The reusability of the material was evaluated by cycling for three times without noticeably reduced catalytic activity. This study provides a novel strategy to achieve partial dechlorination of chlorinated organic pollutants.
Mostrar más [+] Menos [-]Adsorption of aqueous neodymium, europium, gadolinium, terbium, and yttrium ions onto nZVI-montmorillonite: kinetics, thermodynamic mechanism, and the influence of coexisting ions Texto completo
2018
Wang, Jiao
This study reports the adsorption of five rare earth elements (REEs) (belonging to light (Nd, Eu, Gd), medium (Tb), and heavy (Y) REE group) on montmorillonite-supported zero-valent iron nanoparticles (nZVI-M). Various parameters about REEs adsorption were investigated: the pH value, the adsorption kinetic, the maximum adsorption capacity, and the adsorption isotherm. The temperature (293–313 K) had a limited effect on the final adsorption equilibrium capacity and the analysis of thermodynamic studies suggests it was spontaneous (negative values of ∆Gᵒ) and exothermic (negative values of ∆Hᵒ). The system randomness decreased after adsorption (negative values of ∆Sᵒ). In addition, the values of thermodynamic parameters and the activation energy were strongly dependent on the temperature range because different kinds of REEs participated in the reaction in the form of hydrated ions and followed a randomly and complexly dissociative adsorption mechanism. According to the intraparticle diffusion model analysis, the adsorption of REEs on nZVI-M was dominated by chemisorption and the nano size of nZVI-M reduced the diffusion thickness and the resistance to intraparticle diffusion. Based on the characterization of adsorbent by XPS, the adsorption mechanisms of REEs on nZVI-M were ion exchange and surface complexation.
Mostrar más [+] Menos [-]blaNDM-1-producing Vibrio parahaemolyticus and V. vulnificus isolated from recreational beaches in Lagos, Nigeria Texto completo
2018
Oyelade, Abolade A. | Adelowo, Olawale Olufemi | Fagade, Obasola Ezekiel
Twenty-six strains of Vibrio parahaemolyticus and 14 strains of V. vulnificus isolated from selected beaches in Lagos State, Nigeria, were examined for virulence and antimicrobial resistance genes. The V. parahaemolyticus isolates were further serotyped and subjected to pulsed field gel electrophoresis (PFGE). Five strains of V. vulnificus and one of V. parahaemolyticus carried the New Delhi-metallo-beta-lactamase gene blaNDM₋₁, seven strains carried blaTEM, and four strains of V. vulnificus and one of V. parahaemolyticus carried blaCMY. Real-time PCR assay for detection of virulence genes tdh and trh in the V. parahaemolyticus isolates showed that five isolates were positive for tdh, two for trh, and one isolate carried both genes. Ten V. parahaemolyticus serogroups and 23 pulsotypes were identified from 26 isolates based on O and K antigens typing and PFGE. Five of the isolates belong to the pandemic strains O1:Kut and O3:K6, and three belonged to the highly virulent O4:Kut serotype. Nineteen of the isolates showed distinct PFGE banding patterns. These results highlighted the importance of Nigerian recreational beaches as reservoirs of antimicrobial resistance genes of global public health interest, such as blaNDM₋₁.
Mostrar más [+] Menos [-]Lethal and sub-lethal effects of cyproconazole on freshwater organisms: a case study with Chironomus riparius and Dugesia tigrina Texto completo
2018
Saraiva, AlthiérisS. | Sarmento, RenatoA. | Golovko, Oksana | Randak, Tomas | Pestana, JoãoL. T. | Soares, AmadeuM. V. M.
The fungicide cyproconazole (CPZ) inhibits the biosynthesis of ergosterol, an essential sterol component in fungal cell membrane and can also affect non-target organisms by its inhibitory effects on P450 monooxygenases. The predicted environmental concentration of CPZ is up to 49.05 μg/L and 145.89 μg/kg in surface waters and sediments, respectively, and information about CPZ toxicity towards non-target aquatic organisms is still limited. This study aimed to address the lack of ecotoxicological data for CPZ, and thus, an evaluation of the lethal and sub-lethal effects of CPZ was performed using two freshwater invertebrates (the midge Chironomus riparius and the planarian Dugesia tigrina). The estimated CPZ 48 h LC₅₀ (95% CI) was 17.46 mg/L for C. riparius and 47.38 mg/L for D. tigrina. The emergence time (EmT₅₀) of C. riparius was delayed by CPZ exposure from 0.76 mg/L. On the other hand, planarians showed higher tolerance to CPZ exposure. Sub-lethal effects of CPZ on planarians included reductions in locomotion (1.8 mg/L), delayed photoreceptors regeneration (from 0.45 mg/L), and feeding inhibition (5.6 mg/L). Our results confirm the moderate toxicity of CPZ towards aquatic invertebrates but sub-lethal effects observed also suggest potential chronic effects of CPZ with consequences for population dynamics.
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