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Результаты 3981-3990 из 4,309
Profiling the biological effects of wastewater samples via bioluminescent bacterial biosensors combined with estrogenic assays Полный текст
2017
Bazin, Ingrid | Seo, Ho Bin | Suehs, Carey M. | Ramuz, Marc | De Waard, Michel | Gu, Man Bock
Various water samples were successfully evaluated using a panel of different recombinant bioluminescent bacteria and estrogenic activity analysis. The bioluminescent bacteria strains induced by oxidative (superoxide radical or hydroxyl radical), protein damage, cell membrane damage, or cellular toxicity were used. Estrogenic activities were examined by using the yeast strain BY4741, which carries the β-galactosidase reporter gene under the control of the estrogen-responsive element (ERE). A total of 14 samples from three wastewater treatment plants, one textile factory, and seawater locations in Tunisia were analyzed. A wide range of bio-responses were described. Site/sample heterogeneity was prevalent, in combination with generally high relative bioluminescence scores for oxidative stress (OH•). Estrogenic activity was detected at all sites and was particularly elevated at certain sites. Our perspectives include the future exploration of the variation detected in relation to treatment plant operations and environmental impacts. In conclusion, this new multi-experimental method can be used for rapid bio-response profile monitoring and the evaluation of environmental samples spanning a wide range of domains. This study confirms that bio-reactive wastewater treatment plant (WWTP) effluents are discharged into seawater, where they may impact coastal populations.
Показать больше [+] Меньше [-]Lifetime cancer risk assessment for inhalation exposure to di(2-ethylhexyl) phthalate (DEHP) Полный текст
2017
Miao, Yufeng | Wang, Runhuai | Lu, Zhan | Zhao, Jinping | Deng, Qihong
The plasticizer di(2-ethylhexyl) phthalate (DEHP) is ubiquitous in the environment and considered as carcinogen; however, the carcinogenic risk of human exposure to DEHP in the air via inhalation is lacking. A probabilistic incremental lifetime cancer risk (ILCR) model was implemented to quantitatively estimate the potential cancer risk of DEHP via human inhalation by using Monte Carlo simulation. We assessed the cancer risk in different age groups (children, adolescents, and adults) exposed to different DEHP concentrations (background low, indoor moderate, and occupational high) for different durations (2, 8, and 20 years). Results showed that the cancer risk of exposure to DEHP was below the acceptable limit (10⁻⁶) in the ambient air but was serious in indoor and occupational environments even at short exposure duration (2 years). The cancer risk of DEHP via inhalation in children was lower than that in adolescents and adults, but the risk in children via dermal and oral exposure to indoor dust and soft PVC toys should be considered. Sensitivity analysis indicated that the exposure concentration of DEHP was the strongest factor that influenced ILCR. Our work provides the evidence of cancer risk of DEHP via inhalation and highlights the risk in indoor and occupational environments.
Показать больше [+] Меньше [-]A follow-up on the analytical study of discolouration of the marble statues of Orsanmichele in Florence Полный текст
2017
Pinna, Daniela | Galeotti, Monica | Rizzo, Adriana | Cantisani, Emma | Sciutto, Giorgia | Zangheri, Martina | Prati, Silvia | Mazzeo, Rocco | Roda, A. (Aldo)
The research complements the complex study carried out to understand the source of brown discolourations of ten marble statues in the Church of Orsanmichele in Florence, Italy. Originally located in exterior niches, the statues were restored to reverse the extensive alterations they had undergone throughout the centuries. One of the major alterations was the application of a dark brown patina that dated just after 1789. After the statues were placed indoors, brownish discolourations started to appear on their surfaces. Cross sections were examined using FTIR mapping and immunological methods. In parallel, the pyrolysis-gas chromatography/mass spectrometry (py-GC/MS) data already obtained from the statues’ scrapings were compared with data from aged casein films applied to microscope glass slides and aged milk-treated marble. All the statues had been treated with milk-based substances before the time the bronze patina was applied. The values of temperature and illumination of the room were important factors in the ageing of organic substances and in the formation of calcium oxalates. It is likely that products of thermo-oxidation and photo-oxidation of the oils together with the oxalates caused the darkening. The marble samples corresponded to a Lunense provenance.
Показать больше [+] Меньше [-]The spatial distribution and accumulation characteristics of heavy metals in steppe soils around three mining areas in Xilinhot in Inner Mongolia, China Полный текст
2017
Gao, Yongfei | Liu, Honglin | Liu, Guixiang
Metal deposition has become a major environmental problem in China due to its adverse effects on human and ecosystem health, particularly in Inner Mongolia, where frequent dust storms (due to steppe degradation and desertification) and soil pollution (associated with the increasing mining activities) have occurred in recent decades. To assess spatial distribution of heavy metals and the influences of mining activities on geochemical behavior of heavy metals in soils, soil samples with depth of 0–10, 10–20, and 20–30 cm at each site were collected from different directions in the vicinity of three mines (coal mine, gold mine, and fluorite mine) in a typical steppe zone of Inner Mongolia, China. Six elements (Cd, Pb, Zn, Cr, Cu, and Ni) in the soils were analyzed using inductively coupled plasma emission spectrometer (ICP-OES). The results indicated that the average concentrations of Cd, Pb, Zn, Cr, Cu, and Ni in the soil of the study area around three mines were lower than the second class level of the National Soil Environment Safety Standard, but mostly were higher than the background value of soil in the Inner Mongolia. Northwest, southwest, and northeast wind directions have a great influence on the distribution of metals in coal, gold, and fluorite mine area, respectively. The concentration of heavy metals in coal, gold, and fluorite increased with the distance from the center of the mine, then reached a peak, then decreased gradually. The vertical mobility of metals in soil profiles was slightly significant for Cd > Cr > Zn > Ni in coal mine area and was not significant in gold and fluorite mines. Multivariate statistical methods such as principal component analysis and cluster analysis, coupled with correlation coefficient analysis, showed that Cd, Cu, Cr, and Ni in the mining area came from the same source, while Zn and Pb came from the other source. That the sources of heavy metals in the mining area were discussed would not only enhance our knowledge regarding the soil pollution status in the study area but would also provide us information to manage the sources of these elements in the study area.
Показать больше [+] Меньше [-]Asthma disease as cause of admission to hospitals due to exposure to ambient oxidants in Mashhad, Iran Полный текст
2017
Ghaffari, Hamid Reza | Aval, Hamideh Ebrahimi | Alahabadi, Ahmad | Mokammel, Adel | Khamirchi, Ramzanali | Yousefzadeh, Samira | Ahmadi, Ehsan | Rahmani-Sani, Abolfazl | Estaji, Mehdi | Ghanbarnejad, Amin | Gholizadeh, Abdolmajid | Taghavi, Mahmoud | Miri, Mohammad
Nowadays, asthma is one of the most common chronic respiratory diseases, worldwide. Many reports have emphasized the correlation between the short-term exposure to the ambient air pollutants and acute respiratory diseases, especially among children with asthmatic symptoms. The aim of this study was to evaluate the relationship between the exposure to three atmospheric antioxidants (NO₂, SO₂, and O₃) and hospital admission due to asthmatic disease (HAAD) in the city of Mashhad, Iran. The concentrations of atmospheric antioxidants were obtained from the real-time monitoring stations located in the city. The collected data were employed for developing predictive models in the AirQ software. In order to investigate the association between short-term exposure to air pollutants and HAAD, the study participants were categorized into two age groups: less than 15 and from 15 to 64 years old. The results indicated that in people less than 15 years increase in NO₂ (attributable proportion (AP) = 3.775%, 95% CI 0.897–6.883%), SO₂ (AP = 3.649%, 95% CI 1.295–5.937%), and O₃ (AP = 0.554%,95% CI 0.00–3.321) results in increase in HAAD. While for those aged between 15 and 64 years, the AP was 4.192% (95% CI 0.450–7.662%) for NO₂; 0.0% (95% CI 0.00–1.687%) for SO₂; and 0.236% (95% CI 0.00–1.216%) for O₃. The number of asthmatic cases who were less than 15 years admitted to the hospitals during the study period was higher than that of those within the age groups between 15 and 64 years as a consequence of exposure to NO₂ (101 vs. 75), SO₂ (98 vs. 0), and O₃ (15 vs. 3), respectively. To the best of our knowledge, the AirQ model has not been applied before to estimate the effect of atmospheric antioxidant exposure on hospital admission because of asthma disease. Eventually, this model is proposed to be applicable for other cities around the world.
Показать больше [+] Меньше [-]Air pollution and admissions due to ST elevation myocardial infarction—a time-series study from northwest of Iran Полный текст
2017
Ghaffari, Samad | Hajizadeh, Reza | Pourafkari, Leili | Shokouhi, Behrouz | Tajlil, Arezou | Mazani, Sarvin | Kavandi, Hadiseh | Ansari, Hosein | Nader, Nader D.
We investigated the association between the levels of air pollutants and the number of daily admissions due to ST segment elevation myocardial infarction (STEMI) in a metropolitan in the northwest of Iran. Daily concentrations of common air pollutants were obtained for the greater city of Tabriz for a period of 2 years. These reports included sulfur dioxide (SO2), nitrogen dioxide (NO2), nitric oxide (NO), nitrogen byproducts (NOx), carbon monoxide (CO), ozone (O3), and particulate matters < 10 μm (PM10). The census of admissions for STEMI was retrieved for the same period from hospital registries. The association of daily variations in air pollutant levels and the daily number of STEMI admissions were investigated in a time-series analysis. In the multi-pollutant model adjusting for long-term trend, seasonality, and temperature, a significant association was found for 1-h [NO2] and 24-h [CO]. A marginally significant association was observed for 24-h [NO2] and 8-h [CO]. The 24-h [CO] had the strongest association with the number of admissions with STEMI. Maximum 1-h concentrations of NO2 on the same day and on the prior day as well as 24-h concentrations of CO on the prior day were independently associated with increased number of STEMI admissions. However, daily concentrations of SO2, NO, O3, and PM10 were not associated with the frequency of hospital admissions for STEMI.
Показать больше [+] Меньше [-]Molecular and structural changes induced by essential oil treatments in Vicia faba roots detected by FTIR and FTNIR spectroscopy Полный текст
2017
Mecozzi, Mauro | Sturchio, Elena | Boccia, Priscilla | Zanellato, Miriam | Meconi, Claudia | Peleggi, Francesco
Essential oils have recognized antimicrobial and antifungal properties which allow their utilization in agriculture like an alternative to pesticides, but their utilization requires the knowledge of all the potential structural changes and damages produced by the interaction with the vegetal organisms. In this paper, we investigated the effects of two essential oils, the tea tree oil (TTO) and the mixture of clove and rosemary oils (C + R), on the molecular structure of Vicia faba roots by Fourier transform infrared (FTIR) and Fourier near infrared transform (FTNIR) spectroscopy. FTIR spectroscopy showed structural modifications of the absorption bands related to DNA (1100 and 1050 cm⁻¹, carbohydrate backbones, and nucleotide bands within 900 and 850 cm⁻¹), proteins (1700 and 1600 cm⁻¹ amide I band, 1580 and 1520 cm⁻¹ amide II band), and lipids (methylene group of aliphatic chains between 2950 and 2800 cm⁻¹). The changes in the secondary structures of proteins consisted of a denaturation depending on increased presence of random coil structures. In addition, in the samples treated with TTO oils, we observed the presence of protein oxidation, an effect negligible instead for the C + R-treated samples. The modified shapes of the infrared methyl bands of aliphatic chains suggested an increased lipid disorder which could also determine lipid peroxidation. The changes observed for the DNA structures at the highest concentration of the above essential oils can be related to the genotoxic effect of eugenol, an important constituent of both TTO and C + R mixture oils. FTNIR spectroscopy showed the modified shape of the second overtone bands belonging to methyl and methylene groups, between 8500 and 8000 cm⁻¹. This confirmed the increased lipid disorders already observed by FTIR spectroscopy. The results obtained on the probe organism V. faba show that FTIR and FTNIR spectroscopy can become a useful support to the conventional cytogenetic tests used in the evaluation of the allelopathic uses of essential oils in agriculture.
Показать больше [+] Меньше [-]Properties and evolution of dissolved organic matter during co-composting of dairy manure and Chinese herbal residues Полный текст
2017
Li, Qunliang | Lu, Yanyu | Guo, Xiaobo | Shan, Guangchun | Huang, Junhao
Composting is an effective method in treating solid organic wastes, in which dissolved organic matter (DOM) plays an important role in transformation of organic matter and microbial activity. Therefore, an understanding of the properties and evolution of DOM during composting is crucial. In this study, DOM was studied using elemental analysis, spectroscopic analysis (UV-vis, FTIR, and pyrolysis-GC/MS), and colloidal analysis during a 120-day composting. Results showed that the content of N and O in DOM increased while C and H content declined progressively over the composting time. Aliphatic C–H stretching, aromatic C=C or C=O stretching of amide groups, and C–O stretch (carbohydrates) showed an obvious decrease, while COO– and C–N groups had a significant increase. The evolution of DOM indicated a gradual decrease of the lipid and polysaccharide fractions, whereas an increase of aromatic and nitrogenous compounds was observed. The DOM also showed a more stable status, and an accumulation of small molecular compounds occurred with composting proceeded. Taken together, these results shed a good insight into the properties and evolution of DOM during a composting process.
Показать больше [+] Меньше [-]Efficient photo–catalytic degradation of malachite green using nickel tungstate material as photo–catalyst Полный текст
2017
Helaïli, N. | Boudjamaa, A. | Kebir, M. | Bachari, K.
The present study focused on the evaluation of photo-catalytic and photo–electrochemical properties of the photo–catalyst based on nickel tungstate material prepared by a nitrate method through the degradation of malachite green (MG) dye's. The effect of catalyst loading and dye concentration was examined. Physico–chemical, optical, electrical, electrochemical, and photo–electrochemical properties of the prepared material were analyzed by X-ray diffraction (XRD), fourier transform–infrared spectroscopy (FTIR), BET analysis, optical reflectance diffuse (DR), scanning electron microscopy (SEM/EDX), electrical conductivity, cyclic voltammetry (CV), current intensity, mott–shottky, and nyquist. XRD revealed the formation of monoclinic structure with a small particle size. BET surface area of the sample was around 10 m²/g. The results show that the degradation of MG was more than 80%, achieved after 3 h of irradiation at pH 4.6 and with a catalyst loading of 75 mg. Also, it was found that the dye photo–degradation obeyed the pseudo-first order kinetic via Langmuir Hinshelwood model.
Показать больше [+] Меньше [-]Application of phosphate solubilizing bacteria in immobilization of Pb and Cd in soil Полный текст
2017
Yuan, Zhimin | Yi, Honghong | Wang, Tianqi | Zhang, Yiyue | Zhu, Xiaozhe | Yao, Jun
In the present study, heavy metal (HM)-tolerant phosphate solubilizing bacteria (PSB) were isolated and their performance during the remediation of Pb and Cd in contaminated soil was studied. A total of 16 bacterial strains and one consortium were isolated, and the consortium had the highest phosphate solubilizing ability and HM tolerance. Great variations between the Fourier transform infrared (FTIR) spectra of consortium cells before and after adsorption of Pb²⁺ and Cd²⁺ revealed that amide I/amide II bonds and carboxyl on the cell surface were involved in binding of metal ions. High-throughput sequencing technique revealed that the consortium was composed of Enterobacter spp., Bacillus spp., and Lactococcus spp. The consortium was added into contaminated soil, and its potential ability in dissolution of phosphate from Ca₃(PO₄)₂ and subsequent immobilization of HMs was tested. Results showed that when Ca₃(PO₄)₂ was applied at 10.60 mg/g soil, PSB addition significantly increased soil available phosphate content from 12.28 to 17.30 mg/kg, thereby enhancing the immobilization rate of Pb and Cd from 69.95 to 80.76% and from 28.38 to 30.81%, respectively. Microcalorimetric analysis revealed that PSB addition significantly improved soil microbial activity, which was possibly related with the decreased HMs availability and the nutrient effect of the solubilized phosphate. The present study can provide a cost-effective and environmental-friendly strategy to remediate multiple HM-contaminated soils.
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