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Iron loading and secondary multi-trace element deficiency in a dairy herd fed silage grass grown on land fertilized with sewage sludge Full text
2019
Miranda, Marta | Méndez, Luisa | Pereira, Víctor | Minervino, Antonio Humberto Hamad | López Alonso, Marta
Recycling sewage sludge by applying it to agricultural land is strategically important in the European Union and is regulated by Directive 86/278/EEC, aimed at protecting the soil and humans from the presence of unwanted substances. However, because of the ruminant feeding habits, there is a risk that animals grazed on pasture or fed crops grown on land treated in this way may ingest biosolids adhered to foliage and/or on the top soil. This paper describes an episode of toxicity in a dairy herd consuming silage from a field fertilized with sewage sludge produced in a wastewater treatment plant. The affected cows were recumbent, unable to rise and suffered diarrhoea. Analysis of tissues (fresh weight) from a cow that subsequently died revealed severe hepatic iron loading (6720 mg/kg) and secondary multi-trace element hepatic deficiency, particularly of copper (0.812 mg/kg) and manganese (0.436 mg/kg), but also selenium (0.164 mg/kg) and zinc (19.9 mg/kg). The study findings indicate that the use of sewage sludge in agriculture can cause secondary multi-trace element deficiencies in ruminants. Careful attention should be taken when crops are ensilaged avoiding top-soil sewage sludge contamination, since the acidification process may greatly increase Fe bioavailability.
Show more [+] Less [-]Cultivation modes and deficit irrigation strategies to improve 13C carbon isotope, photosynthesis, and winter wheat productivity in semi-arid regions Full text
2019
Shahzād, ʻAlī | Xu, Yueyue | Ma, Xiangcheng | Henchiri, Malak | Cai, Tie | Ren, Xiaolong | Zhang, Jiahua | Jia, Zhikuan
Determining the effect of ridge-furrow cultivation mode on ¹³C carbon isotope discrimination, photosynthetic capacity, and leaf gas exchange characteristics of winter wheat leaves will help to increase wheat production. To verify these effects of cultivation modes with deficit irrigation will provide scientific basis for determining water-saving strategy. Therefore, a mobile rainproof shelter was used to explore the potential benefit of two cultivation modes: (1) the ridge-furrow (RF) precipitation system and (2) traditional flat planting (TF) with two deficit irrigation levels (150, 75 mm) and three precipitation levels (275 mm, 200 mm, 125 mm) were tested in this study. Plastic film mulching on ridges had significant effects on rainwater collection and improved soil water retention. Analysis of the light-response curve showed that RF2₁₅₀ treatment significantly increased flag leaf net photosynthetic rate (Pₙ), stomatal conductance (Gₛ), intercellular CO₂ concentration (Cᵢ), transpiration rate (Tᵣ), leaf WUE, and total contents of chlorophyll ab of wheat at flowering stage than that of TF planting. The RF system significantly increases maximum net photosynthetic rate (Pₙₘₐₓ) (16.2%), light saturation points (LSP) (6.7%), and Pₙ under CO₂-response curves compared to the TF cultivation across the two irrigation and three simulated rainfall levels. The RF system significantly increased Δ¹³C (0.7%) and caused a notable increase in the intercellular to ambient CO₂ concentration ratio (7.6%), dry matter translocation (54.9%), and grain yield plant⁻¹ (19%) compared to the TF planting. Furthermore, Δ¹³C was significantly positively correlated with Pₙ, Gₛ, Cᵢ/Cₐ, Cᵢ, Tᵣ, Pₙₘₐₓ, LSP, and grain yield. This study suggested that the RF2₁₅₀ treatment was the best water-saving technique because it increased soil water content, Δ¹³C, biomass, grain yield, and leaf WUE.
Show more [+] Less [-]Association between prenatal exposure to perfluoroalkyl substances and asthma-related diseases in preschool children Full text
2019
Zeng, Xinxin | Chen, Qian | Zhang, Xi | Li, Huajun | Liu, Quanhua | Li, Chunxiao | Ma, Ming | Zhang, Jianhua | Zhang, Weixi | Zhang, Jun | Huang, Lisu
Thus far, the few studies on the associations between perfluoroalkyl substances (PFASs) and asthma in children have yielded inconsistent results. In this study, we aimed to evaluate whether and to what extent prenatal PFASs exposure is associated with childhood asthmatic diseases. Eight PFASs were measured in cord blood drawn from 358 children in the Shanghai Allergy Birth Cohort, and a 5-year follow-up plan was completed. Asthma was diagnosed and reported by pediatric respiratory physicians via repeated symptoms (wheezing and coughing) and laboratory examination (Immunoglobulin E level test and skin prick test). A total of 26.6% and 17.4% subjects were diagnosed with wheezing and asthma, respectively. Multivariable logistic regression and piecewise linear regression were applied, and no association was found between PFASs and asthma or wheezing. However, cord serum PFOA, PFOS, and PFDA were positively correlated with serum total IgE in 5-year-old children as the level of the former beyond the turning point (4.37 ng/mL, 2.95 ng/mL, and 0.42 ng/mL, respectively), but negatively with IgE before it reach turnning point.
Show more [+] Less [-]Ozonation catalyzed by iron- and/or manganese-supported granular activated carbons for the treatment of phenol Full text
2019
Xiong, Wei | Chen, Nan | Feng, Chuanping | Liu, Yang | Ma, Ningping | Deng, Jian | Xing, Linlin | Gao, Yu
Iron- and/or manganese-supported catalysts on granular activated carbons (Fe and/or Mn/GACs) were prepared, and their catalytic activities were evaluated by using them to treat phenol and secondary petrochemical effluent via ozonation. The presence of Fe and/or Mn/GACs significantly improved the degradation and degree of phenol mineralization. Changes in dissolved ozone concentrations and the effects of carbonate and tert-butyl alcohol (TBA) indicated that the prepared catalyst enhanced the decomposition of ozone into hydroxyl radicals (·OH), which was determined to be a key factor in catalyzing the ozonation of phenol. Typical intermediate products were identified by GC-MS and HPLC analysis, and a possible degradation pathway of phenol via catalytic ozonation was proposed. The results of XPS, CV, and other experimental data indicated that introducing Fe and/or Mn increased the rate of ozone decomposition into ·OH, and also enhanced the interfacial electron transfer by Fe²⁺-Fe³⁺ and Mn²⁺-Mn³⁺-Mn⁴⁺ redox cycles, resulting in higher catalytic activity. However, the Fe-Mn/GAC surface was shown to undergo galvanic corrosion between Fe₃O₄ and MnO₂, decreasing the catalytic activity. In addition, catalytic ozonation was used to treat secondary petrochemical effluent. The results demonstrated that the Mn/GAC/O₃ system significantly improved the quality of phenol-containing wastewater in terms of its COD, TOC, NH₄⁺-N, water color, and ecotoxicity. This study gives a better understanding of the phenol treatment by catalytic ozonation using Fe and/or Mn/GAC.
Show more [+] Less [-]Occurrence, virulence, and antimicrobial resistance of Vibrio parahaemolyticus isolated from bivalve shellfish farms along the southern coast of Korea Full text
2019
Ryu, A Ra | Mok, Jong Soo | Lee, Da Eun | Kwon, Ji Young | Park, Kunbawui
Vibrio parahaemolyticus is the most common pathogen causing seafood-borne illnesses in Korea. The present study evaluated the occurrence, virulence, and antimicrobial resistance of V. parahaemolyticus in seawater and bivalves obtained in 2016 from the southern coast of Korea, an important region for commercial aquaculture industries, especially the Korean raw seafood culture. V. parahaemolyticus was detected in 87 of 160 (54.4%) bivalve samples and in 32 of 130 (24.5%) seawater samples. Especially high levels were detected during summer to early autumn. All the seawater and bivalves contained less than 2 and 5% of the tdh and trh genes of the isolates, respectively, and seawater isolates possessed two fewer genes than the bivalve isolates. Of 23 antimicrobials tested, three agents (ofloxacin, norfloxacin, and trimethoprim/sulfamethoxazole) effectively treated V. parahaemolyticus illness due to the sensitivity of the isolates. The isolates were highly resistant to ampicillin, however, excluding it as a treatment option. More than half of the isolates exhibited resistance to at least three antimicrobials. These findings indicate the importance of an integrated monitoring and surveillance program noting the occurrence, virulence, and antimicrobial resistance patterns of V. parahaemolyticus in various aquatic sources for preventing human health risks from seafood consumption.
Show more [+] Less [-]Performance of machine-learning algorithms to pattern recognition and classification of hearing impairment in Brazilian farmers exposed to pesticide and/or cigarette smoke Full text
2019
Tomiazzi, Jamile Silveira | Pereira, Danillo Roberto | Judai, Meire Aparecida | Antunes, Patrícia Alexandra | Favareto, Ana Paula Alves
The use of pesticides has been increasing in agriculture, leading to a public health problem. The aim of this study was to evaluate ototoxic effects in farmers who were exposed to cigarette smoke and/or pesticides and to identify possible classification patterns in the exposure groups. The sample included 127 participants of both sexes aged between 18 and 39, who were divided into the following four groups: control group (CG), smoking group (SG), pesticide group (PG), and smoking + pesticide group (SPG). Meatoscopy, pure tone audiometry, logoaudiometry, high-frequency thresholds, and immittance testing were performed. Data were evaluated by artificial neural network (ANN), K-nearest neighbors (K-NN), and support vector machine (SVM). There was symmetry between the right and left ears, an increase in the incidence of hearing loss at high frequency and of downward sloping audiometric curve configuration, and alteration of stapedial reflex in the three exposed groups. The machine-learning classifiers achieved good classification performance (control and exposed). The best classification results occur in high type (I and II) datasets (about 90% accuracy) in k-NN test. It is concluded that both xenobiotic substances have ototoxic potential; however, their combined use does not present additive or potentiating effects recognizable by the algorithms.
Show more [+] Less [-]Assessment of metal enrichment and bioavailability in mangrove and mudflat sediments of the tropical (Zuari) estuary, west coast of India Full text
2019
Gadkar, Nikita S. | Nayak, Ganapati N. | Nasnodkar, Maheshwar R.
Mangrove and mudflat sediment cores at the confluence point of the Cumbarjua Canal and the Zuari River were collected and analyzed to assess metal enrichment and bioavailability, with the background of significant bioaccumulation reported in earlier studies within the Zuari Estuary, a recipient of open-cast mining waste containing Fe and Mn. Metals were enriched in mangrove and mudflat sediments due to additions from natural and anthropogenic sources. Contamination factor showed moderate degree of contamination of Fe, Mn, Cu, and Co in mangroves while of Fe, Mn, and Co in mudflats. Pollution load index suggested metal pollution in the sediments of the Zuari Estuary. Metal speciation study indicated largely lithogenic source of Fe (in mudflats), Cu, Zn, and Co, whereas abundant bioavailable Fe (in mangroves) and Mn (in both mangroves and mudflats) suggest their possible mobilization, preferential accumulation, and bioavailability. Further, sediment quality values indicated toxicity of bioavailable Mn and Co, and risk assessment code revealed medium risk of Mn to sediment associated organisms.
Show more [+] Less [-]Fuzzy risk assessment of modified polychlorinated naphthalenes for enhanced degradation Full text
2019
Gu, Wenwen | Li, Qing | Li, Yu
The three-dimensional quantitative structure-activity relationship (3D-QSAR) model is established for polychlorinated naphthalenes (PCNs) using the biological degradability (total score) results to modify CN-56 to design 37 new derivatives with higher degradability (increased by 14.55–38.79%). Furthermore, five new CN-56 derivatives are selected through evaluation of their persistent organic pollutant properties (toxicity, bioconcentration, long-range transport) and practicability (stability, insulativity, flame retardancy) using 3D-QSAR, density functional theory (DFT) and molecular docking methods. Environmental and health-based risk assessments are conducted using the multimedia fugacity model and fuzzy theory for complete screening of the new CN-56 derivatives. Whereas CN-56 is classed as high risk, three new derivatives can be classed as medium risk. The biodegradability mechanism analysis of the PCNs indicates that the electrostatic property is the main factor that affects the degradability, which provides a favorable theoretical reference to obtain environmentally friendly fire retardant and insulating materials.
Show more [+] Less [-]Maternal exposure to perfluorooctanoic acid (PFOA) causes liver toxicity through PPAR-α pathway and lowered histone acetylation in female offspring mice Full text
2019
Li, Danyang | Zhang, Linchao | Zhang, Yan | Guan, Shuo | Gong, Xincheng | Wang, Xiaodan
The study was conducted to investigate the liver toxicity in female offspring mice induced by maternal exposure to perfluorooctanoic acid (PFOA). Fifty pregnant Kunming mice were randomly divided into 5 groups with 10 of each, which were treated with 0.2 mL PFOA solution dissolved with deionized water at 0, 1, 2.5, 5, and 10 mg/kg BW, respectively, from the pregnancy day (PND) 0 to day 17. Female offspring mice were sacrificed to collect serum and liver at postpartum day 21. The results showed that PFOA significantly reduced the body weight at weaning and the survival rate of the female offspring mice (P < 0.01) increased the liver index of the pups (P < 0.01). Meanwhile, PFOA also caused hepatic bleeding, local necrosis, and enlargement of hepatocytes and vacuolization. The levels of serum AST, ALT, SOD, and CAT in PFOA treatment group were upregulated significantly (P < 0.01). The expressions of Acot1, Acox1, and Acsl1 genes were increased significantly (P < 0.01). The expression of PPAR-α gene was decreased significantly (P < 0.01). There was no significant difference in the expression of Cpt1a gene among the 5 groups. HAT activity was reduced significantly and HDAC activity was increased significantly. The expression of anti-acetyl-histone H3 and acetyl-histone H4 was reduced significantly. Thus, our findings indicate that exposure to PFOA during pregnancy affects the growth and development of the pups and causes liver damage, disrupting the secretion of enzymes involved in fatty acid oxidation induced by PPAR-α, leading to liver oxidative stress and a decrease in the degree of histone acetylation. Elevated HDAC may aggravate downstream fatty acid metabolism disorders through PPAR-α.
Show more [+] Less [-]Effects of the export product quality on carbon dioxide emissions: evidence from developing economies Full text
2019
Fang, Jianchun | Gözgor, Giray | Lü, Zhou | Wu, Wanshan
Using the new measure of the export quality of the International Monetary Fund (IMF), this paper investigates the effects of the product quality of exports on the growth rate of the per capita carbon dioxide emissions. The paper focuses on the panel dataset of 82 developing economies for the period from 1970 to 2014. Along with the index of export quality, we also consider the measures of the per capita income, per capita energy consumption, natural resource rents, and trade openness. The results indicate that there is the positive impact of the quality of exports on carbon dioxide emissions. There is also the positive relationship between the per capita income and carbon dioxide emissions. In addition, we find that the trade openness measures are positively related to carbon dioxide emissions. These results are robust to consider different income measures and to divide the developing economies, according to their income levels.
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