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Possible protective role of elderberry fruit lyophilizate against selected effects of cadmium and lead intoxication in Wistar rats
2016
Kopeć, Aneta | Sikora, Elżbieta | Piątkowska, Ewa | Borczak, Barbara | Czech, Tomasz
The objective of this study was the investigation whether the administration of the elderberry fruit lyophilizate under exposure to cadmium(Cd) and (Pb) lead may protect against some effects of their toxic action in Wistar rats. Rats were fed with diets containing Cd (Cd 0.025 mg/kg b.m.) or Pb (Pb 0.025 mg /kg b.m.) with the addition of the freeze-dried elderberry fruits (BEF) in the amount of 5 %. BEF added to the diet with Cd significantly decreased the activity of AST and ALT compared to the rats fed with the control diet with Cd (C + Cd). Activity of glutathione peroxidase was significantly higher in the blood of rats fed with BEF diet compared with animals fed with BEF + Cd, BEF + Pb, and C + Pb diets. Addition of BEF to the diets with Cd or Pb significantly decreased the uric acid concentration compared to the level of this parameter in the serum of animals fed with control diets containing Cd or Pb. The level of the Cd significantly decreased in the livers of rodents fed with BEF + Cd diet as compared to the concentration of this metal in the livers of rats fed with C + Cd diet. Elderberry fruit lyophilizate did not protect against the increased concentration of Cd or Pb in kidneys and bones of experimental rats; however, it improved the function of livers and kidneys, especially of rats intoxicated with Cd.
显示更多 [+] 显示较少 [-]Expression of copper-resistance genes in microbial communities under copper stress and oxic/anoxic conditions
2016
Besaury, Ludovic | Pawlak, Barbara | Quillet, Laurent
Microorganisms have developed copper-resistance mechanisms in order to survive in contaminated environments. The abundance and expression of the copper-resistance genes cusA and copA, encoding respectively for a Resistance Cell Nodulation protein and for a P-type ATP-ase pump, was assessed along a gradient of copper concentration in microcosms prepared from Seine estuary mudflat sediment. We demonstrated that the abundance of copA and cusA genes decreased with the increase of copper concentration and that cusA gene was up to ten times higher than the copA gene. Only the copA gene was expressed in both oxic and anoxic conditions. The abundance and activity of the microbial community remained constant whatever the concentrations of copper along the gradient. The molecular phylogeny of the two copper-resistance genes was studied and revealed that the increase of copper increased the diversity of copA and cusA gene sequences.
显示更多 [+] 显示较少 [-]Effect of operation parameters on the flux stabilization of gravity-driven membrane (GDM) filtration system for decentralized water supply
2016
Tang, Xiaobin | Ding, An | Qu, Fangshu | Jia, Ruibao | Chang, Haiqing | Cheng, Xiaoxiang | Liu, Bin | Li, Guibai | Liang, Heng
A pilot-scale gravity-driven membrane (GDM) filtration system under low gravitational pressure without any pre-treatment, backwash, flushing, or chemical cleaning was carried out to investigate the effect of operation parameters (including operation pressure, aeration mode, and intermittent filtration) on the effluent quality and permeability development. The results revealed that GDM system exhibited an efficient performance for the removal of suspended substances and organic compounds. The stabilization of flux occurred and the average values of stable flux were 6.6, 8.1, and 8.6 Lm⁻² h⁻¹ for pressures of 65, 120, and 200 mbar, respectively. In contrast, flux stabilization was not observed under continuous and intermittent aeration conditions. However, aeration (especially continuous aeration) was effective to improve flux and alleviate membrane fouling during 1-month operation. Moreover, intermittent filtration would influence the stabilization of permeate flux, resulting in a higher stable flux (ranging from 6 to 13 Lm⁻² h⁻¹). The stable flux significantly improved with the increase of intermittent period. Additionally, GDM systems exhibited an efficient recovery of flux after simple physical cleaning and the analyses of resistance reversibility demonstrated that most of the total resistance was hydraulic reversible resistance (50–75 %). Therefore, it is expected that the results of this study can develop strategies to increase membrane permeability and reduce energy consumption in GDM systems for decentralized water supply.
显示更多 [+] 显示较少 [-]Bioanalytical and instrumental screening of the uptake of sediment-borne, dioxin-like compounds in roach (Rutilus rutilus)
2016
Eichbaum, Kathrin | Brinkmann, Markus | Nuesser, Leonie | Buchinger, Sebastian | Reifferscheid, Georg | Codling, Garry | Jones, Paul | Giesy, John P. | Hecker, Markus | Hollert, Henner
To examine the uptake of dioxin-like compounds (DLCs), common roaches (Rutilus rutilus) were exposed for 28 days to differently contaminated sediments from two major European rivers in a purpose-built facility. Dietary transfer of DLCs was investigated by exposing fish to sediments inoculated or non-inoculated with black worms (Lumbriculus variegatus). Dioxin-like polychlorinated biphenyls (DL-PCBs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), measured via high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS) in sediments and whole fish, were used to calculate toxicity equivalent quotients (TEQs). TEQs were compared with biological toxicity equivalent quotients (BEQs) determined via the 7-ethoxyresorufin-O-deethylase (EROD) assay, performed with mammalian (H4IIE) and fish (RTL-W1) liver cell lines. TEQs and BEQs indicated an uptake of sediment-borne DLCs by roach, which was independent of sediment contamination levels, but rather reflected sediment-specific characteristics. For most sediment treatments, DLC uptake did not increase with time. Highest congener-specific uptake (DL-PCB 123) was 10-fold compared to control. Exposure to worm-inoculated sediment of highest overall DLC contamination caused a 2-fold (TEQ and H4IIE BEQ) greater uptake of DLCs by fish compared to the respective non-inoculated treatment. H4IIE cells showed the greatest sensitivity (0.37 ± 0.25 pM TCDD) and the strongest correlation with TEQs (r ² = 0.79), hence, they seem to be best suited for DLC screening of sediments and biota, amended by compound-specific instrumental analysis if required.
显示更多 [+] 显示较少 [-]Supervised neural computing solutions for fluorescence identification of benzimidazole fungicides. Data and decision fusion strategies
2016
Suárez Araujo, Carmen Paz | García Báez, Patricio | Sánchez Rodríguez, Álvaro | Santana-Rodrríguez, José Juan
Benzimidazole fungicides (BFs) are a type of pesticide of high environmental interest characterized by a heavy fluorescence spectral overlap which complicates its detection in mixtures. In this paper, we present a computational study based on supervised neural networks for a multi-label classification problem. Specifically, backpropagation networks (BPNs) with data fusion and ensemble schemes are used for the simultaneous resolution of difficult multi-fungicide mixtures. We designed, optimized and compared simple BPNs, BPNs with data fusion and BPNs ensembles. The information environment used is made up of synchronous and conventional BF fluorescence spectra. The mixture spectra are not used in the training nor the validation stage. This study allows us to determine the convenience of fusioning the labels of carbendazim and benomyl for the identification of BFs in complex multi-fungicide mixtures.
显示更多 [+] 显示较少 [-]Detection of human fecal contamination by nifH gene quantification of marine waters in the coastal beaches of Rio de Janeiro, Brazil
2016
Oliveira, Samara Sant’Anna | Sorgine, Marcos Henrique Ferreira | Bianco, Kayo | Pinto, Leonardo Henriques | Barreto, Camila | Albano, Rodolpho Mattos | Cardoso, Alexander Machado | Clementino, Maysa Mandetta
The identification of fecal pollution in aquatic ecosystems is one of the requirements to assess the possible risks to human health. In this report, physicochemical parameters, Escherichia coli enumeration and Methanobrevibacter smithii nifH gene quantification were conducted at 13 marine waters in the coastal beaches of Rio de Janeiro, Brazil. The pH, turbidity, dissolved oxygen, temperature, and conductivity, carried out by mobile equipment, revealed varied levels due to specific conditions of the beaches. The bioindicators’ enumerations were done by defined substrate method, conventional, and real-time PCR. Six marine beach sites (46 %) presenting E. coli levels in compliance with Brazilian water quality guidelines (<2500 MPN/100 mL) showed nifH gene between 5.7 × 10⁹ to 9.5 × 10¹¹ copies. L⁻¹ revealing poor correlation between the two approaches. To our knowledge, this is the first inquiry in qPCR using nifH gene as a biomarker of human-specific sources of sewage pollution in marine waters in Brazil. In addition, our data suggests that alternative indicator nifH gene could be used, in combination with other markers, for source tracking studies to measure the quality of marine ecosystems thereby contributing to improved microbial risk assessment.
显示更多 [+] 显示较少 [-]Breakage and regrowth of flocs formed by sweep coagulation using additional coagulant of poly aluminium chloride and non-ionic polyacrylamide
2016
Nan, Jun | Yao, Meng | Chen, Ting | Li, Shengnan | Wang, Zhenbei | Feng, Gao
The breakage and regrowth of flocs formed by sweep flocculation were investigated on different flocculation mechanisms using additional dosage coagulant of poly aluminium chloride (PACl) and non-ionic polyacrylamide (PAM) to explore the reversibility after floc breakage. The optimal dosage of PACl was 0.15 mM (as alum), and zeta potential exceeding 1 mV meant that sweep flocculation was dominant in the pre-flocculated process. Re-coagulation efficiency increased with additional coagulants dosing, and sedimentation rates of flocs re-formed by small additional dosage of non-ionic PAM are faster than that of flocs re-formed by additional PACl. For additional inorganic coagulant (PACl) during regrowth processes, few negatively charged particles that existed in water sample restricted the effect of charge neutralization. An amorphous aluminum hydroxide precipitation could re-activate the weaker points on the broken floc surface, but regrown flocs have loose structure indicating worse settleability. For additional non-ionic PAM dosing, lower dosage showed large values of fractal dimension and average size, probably due to that unfolded curly molecular chain and exposed amide groups of non-ionic PAM which provide superb conditions for amide group interacting with particles. The use of non-ionic PAM in flocculation has advantage of being more effective than the cationic PACl, probably because it may avoid the re-stabilization of broken flocs by polymer adsorption driven by electrostatic attraction. Hence, appropriate dosing of PAM after breakage could improve the flocs characteristics with large size and compact structure.
显示更多 [+] 显示较少 [-]Acute toxicity assessment of explosive-contaminated soil extracting solution by luminescent bacteria assays
2016
Xu, Wenjie | Jiang, Zhenming | Zhao, Quanlin | Zhang, Zhenzhong | Su, Hongping | Gao, Xuewen | Ye, Zhengfang
Explosive-contaminated soil is harmful to people’s health and the local ecosystem. The acute toxicity of its extracting solution was tested by bacterial luminescence assay using three kinds of luminescent bacteria to characterize the toxicity of the soil. An orthogonal test L ₁₆ (4⁵) was designed to optimize the soil extracting conditions. The optimum extracting conditions were obtained when the ultrasonic extraction time, ultrasonic extraction temperature, and the extraction repeat times were 6 h, 40 °C, and three, respectively. Fourier transform infrared spectroscopy (FTIR) results showed that the main components of the contaminated soil’s extracting solution were 2,4-dinitrotoluene-3-sulfonate (2,4-DNT-3-SO₃ ⁻); 2,4-dinitrotoluene-5-sulfonate (2,4-DNT-5-SO₃ ⁻); and 2,6-dinitrotoluene (2,6-DNT). Compared with Photobacterium phosphoreum and Vibrio fischeri, Vibrio qinghaiensis sp. Nov. is more suitable for assessing the soil extracting solution’s acute toxicity. Soil washing can remove most of the contaminants toxic to luminescent bacterium Vibrio qinghaiensis sp. Nov., suggesting that it may be a potential effective remediation method for explosive-contaminated soil.
显示更多 [+] 显示较少 [-]Pilot project at Hazira, India, for capture of carbon dioxide and its biofixation using microalgae
2016
Yadav, Anant | Choudhary, Piyush | Atri, Neelam | Teir, Sebastian | Mutnuri, Srikanth
The objective of the present study was to set up a small-scale pilot reactor at ONGC Hazira, Surat, for capturing CO₂ from vent gas. The studies were carried out for CO₂ capture by either using microalgae Chlorella sp. or a consortium of microalgae (Scenedesmus quadricauda, Chlorella vulgaris and Chlorococcum humicola). The biomass harvested was used for anaerobic digestion to produce biogas. The carbonation column was able to decrease the average 34 vol.% of CO₂ in vent gas to 15 vol.% of CO₂ in the outlet gas of the carbonation column. The yield of Chlorella sp. was found to be 18 g/m²/day. The methane yield was 386 l CH₄/kg VSfₑd of Chlorella sp. whereas 228 l CH₄/kg VSfₑd of the consortium of algae.
显示更多 [+] 显示较少 [-]Variation in nitrate isotopic signatures in sewage for source apportionment with urbanization: a case study in Beijing, China
2016
Xian, Chaofan | Ouyang, Z. (Zhiyun) | Li, Yanmin | Xiao, Yang | Ren, Yufen
Nitrate (NO₃ ⁻) pollution is a severe problem in urban aquatic systems especially within megacity undergoing rapid urbanization, and mostly, sewage is supposed as the prevailing NO₃ ⁻ source. A dual isotope approach (δ ¹⁵N-NO₃ ⁻ and δ ¹⁸O-NO₃ ⁻) was applied to explore the variation in NO₃ ⁻ isotopic signatures in sewage processed by wastewater treatment plants (WWTPs) in Beijing from 2014 to 2015. We found that the raw and treated sewage owned the different NO₃ ⁻ isotopic signatures, including δ ¹⁵N from 1.1 to 24.7 ‰ and δ ¹⁸O from 1.6 to 22.8 ‰ in raw sewage, as well as δ ¹⁵N from 6.1 to 22.8 ‰ and δ ¹⁸O from 1.6 to 13.2 ‰ in treated effluents. The WWTP processing would result in the enrichment of NO₃ ⁻ isotopic compositions in discharged effluents with NO₃ ⁻ concentrations increasing. Besides, advanced sewage treatment technology with more pollutant N reduction may raise the heavier NO₃ ⁻ isotopic compositions further. The NO₃ ⁻ isotope value ranges of urban sewage and manure should be separated, and the seasonal and tighter NO₃ ⁻ isotope value ranges are supposed to improve the accuracy of source apportionment. The NO₃ ⁻ isotope value ranges conducted in this study might provide useful information for tracing NO₃ ⁻ sources towards the implementation of efficient water pollution control in Beijing.
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