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Genetic aberrations of the K-ras proto-oncogene in bladder cancer in relation to pesticide exposure Texto completo
2018
Hameed, Diaa A. | Yassa, Heba A. | Agban, Michael N. | Hanna, Randa T. | Elderwy, Ahmed M. | Zwaita, Mohamed A.
In Egypt, bladder cancer is one of the most popular cancers, accounting for 31% of all cancer cases. It ranks first in males about 16.2% of male cancer. The incidence in rural areas among males is near 32 per 100,000. The exact etiology of bladder cancer is still unknown; K-ras gene is known as a critical DNA target for chemical carcinogens such as pesticide. Some occupational hazard exposure is thought to be directly genotoxic, while others might enhance the mutagenicity and carcinogenicity of directly acting genotoxic agents. Analysis of the relationship between pesticide exposure and mutation in the K-ras gene in human bladder cancer. One hundred patients were diagnosed with bladder cancer and two hundred controls attended the outpatient clinic; after taking consent and filling a questionnaire for age, sex, occupation and pesticide exposure, surgically resected specimens were collected and the samples were used to determine the k-ras mutation. Blood samples were taken to analyze the level of acetylcholinesterase enzyme and level of P₅₃. The present study indicated that pesticide exposure may play a great role in malignant transformation of the bladder cells through mutation in the K-ras gene; there was a significant correlation between the acetylcholinesterase enzyme level and k-ras mutation (p < 0.001). The results revealed that the level of P₅₃ was significantly high in comparison with the control group (p < 0.001). These findings give an alarm to decrease the amount of pesticides used in our area; also, p₅₃ may be used as an indicator to bladder cancer.
Mostrar más [+] Menos [-]Methylmercury and diphenyl diselenide interactions in Drosophila melanogaster: effects on development, behavior, and Hg levels Texto completo
2018
Leão, Mayara B. | da Rosa, Paulo C. C. | Wagner, Caroline | Lugokenski, Thiago H. | Dalla Corte, Cristiane L.
Methylmercury (MeHg) is a highly toxic environmental pollutant which binds with a high affinity to selenol groups. In view of this, seleno-compounds have been investigated as MeHg antidotes. In the present study, we evaluated the effects of the co-exposure to MeHg and the seleno-compound diphenyl diselenide (PhSe)₂ on Drosophila melanogaster. We measured the survival rate, developmental survival, locomotor ability, reactive oxygen species (ROS) production, and Hg levels in D. melanogaster exposed to MeHg and/or (PhSe)₂ in the food. Exposure to MeHg caused a reduction in the survival rate, developmental survival, and locomotion in D. melanogaster. In addition, MeHg increased the ROS production and mercury levels in flies. The co-exposure to MeHg and (PhSe)₂ did not prevent the toxic effects of MeHg in D. melanogaster. On the contrary, the co-exposure enhanced the toxic effects on the locomotor ability and developmental survival. This effect may be explained by the fact that the co-exposure increased the Hg levels in body when compared to flies exposed only to MeHg, suggesting that MeHg and (PhSe)₂ interaction may increase Hg body burden in D. melanogaster which could contribute for the increased toxicity observed in the co-exposure.
Mostrar más [+] Menos [-]Performance and microbial community of CIC anaerobic reactor treating food waste under different grease contents and inner circulation ratio Texto completo
2018
Su, Chengyuan | Zhao, Lijian | Liao, Liming | Qin, Jingjing | Lu, Yuxiang | Chen, Menglin | Huang, Mei | Huang, Zhi
High concentrations of grease easily inhibit anaerobic digestion. The stability of the process and microbial responses in the controlling internal circulation (CIC) reactor used for treating food waste were investigated under different grease contents and inner circulation ratios. Results showed that at the grease content of 1 g/L, the removal rates of 94% and 86–93% were achieved for chemical oxygen demand (COD) and NH₃–N, respectively. In contrast, when the grease content increased to 7 g/L, removal rates for COD and NH₃–N significantly decreased to 42.8 and 10%, respectively. In the three-dimensional excitation and emission matrix (3D-EEM) spectra of LB-EPS (loosely bound extracellular polymeric substances), the fluorescence intensity of coenzyme F₄₂₀ was weakened in the granular sludge, and the fluorescence peak of aromatic protein disappeared in the TB-EPS (tightly bound EPS). The activity and stability of the granular sludge deteriorated with increasing grease content, in this case at 7 g/L. However, when the inner cycle ratio was increased to 4, the removal rate of COD and NH₃–N increased to about 70 and 76%, respectively. The adverse effects of grease could be decreased by increasing the inner cycle ratio. When the grease content increased from 1 to 7 g/L, the abundance of Methanofollis increased from 9.93 to 46.41%, while Methanothrix abundance was reduced from 18.4 to 3.07%. It could indicate that Methanothrix was sensitive to high grease content.
Mostrar más [+] Menos [-]Total and available metal concentrations in soils from six long-term fertilization sites across China Texto completo
2018
Guan, Dong-Xing | Sun, Fusheng | Yu, Guang-Hui | Polizzotto, Matthew L. | Liu, Yun-Gen
Approximately 19% of agricultural soils in China are contaminated by heavy metals. However, the effects of agricultural management practices on soil contamination are not well understood. Taking advantage of six long-term (23–34 years) field sites across China, this study examined the effects of different agricultural fertilization treatments, including control (no fertilization), inorganic nitrogen, phosphorus and potassium fertilization (NPK), manure fertilization (M), and NPK plus manure fertilization (NPKM), on the total and available metal concentrations in soils. The results showed that after 23–34 years of fertilization, the M and NPKM treatments significantly increased the total concentration of cadmium (Cd), copper (Cu), and zinc (Zn) in soils compared with the concentrations measured for the control and NPK treatments. In contrast, the fertilization treatments had almost no influence on soil lead (Pb) and nickel (Ni) concentrations. The results of analysis via diffusive gradients in thin films demonstrated that long-term sheep or cattle manure fertilization increased the available metals, especially Cd, Cu, and Zn, but long-term swine manure application decreased the available metals, except for Cu and Zn, in soils. Further analysis revealed that the manure source, soil pH level, and biogeochemical properties of metals affected the availability of Cd, Cu, Pb, Zn, and Ni in soils. Collectively, organic fertilizers had the potential to reduce metal uptake by crops, but caution should be taken to reduce metal concentrations in manure.
Mostrar más [+] Menos [-]Analysis of a photobioreactor scaling up for tertiary wastewater treatment: denitrification, phosphorus removal, and microalgae production Texto completo
2018
Villaseñor Camacho, José | Fernández Marchante, Carmen María | Rodríguez Romero, Luis
The present work studies the removal of nutrients (nitrate and phosphate) from a synthetic wastewater simulating a secondary treatment effluent using the microalgae Chlorella vulgaris in autotrophic photobioreactors, together with an analysis of the critical points affecting the scaling-up process from laboratory to pilot scale. Laboratory experiments were done in open agitated 1-L photobioreactors under batch operation mode, while pilot-scale experiments were done using a 150-L closed tubular photobioreactor under continuous operation mode. In both scales, nitrate was the limiting substrate and the effect of its concentration on microalgae performance was studied. From laboratory experiments, an average microalgae productivity of 85 mgVSS L⁻¹ day⁻¹ and approximate maximum N-NO₃⁻ and P-PO₄³⁻ removal rates of 8 mg N gVSS⁻¹ day⁻¹, and 2.6 mg P gVSS⁻¹ day⁻¹ were found. Regarding pilot scale, the average microalgae productivity slightly decreased (76 mgVSS L⁻¹ day⁻¹) while the approximate maximum N-NO₃⁻ and P-PO₄³⁻ removal rates slightly were increased (11.7 mg N gVSS⁻¹ day⁻¹ and 3.04 mg P gVSS⁻¹ day⁻¹) with respect to the laboratory-scale results. The pilot-scale operation worked under lower levels of turbulence and higher dissolved oxygen concentration and light intensity than laboratory experiments; those parameters were difficult to control and they can be identified as the critical points in the differences found on both nutrient removal and microalgae production.
Mostrar más [+] Menos [-]Is there any association between phthalate exposure and precocious puberty in girls? Texto completo
2018
Hashemipour, Mahin | Kelishadi, Roya | Amin, MohammadMehdi | Ebrahim, Karim
Considerable increase in the prevalence of precocious puberty (PP) during the last decade has raised a lot of concerns. Some environmental endocrine disruptor chemicals (EDCs), such as phthalate esters, have intrinsic estrogen activity or increase endogenous sex hormone levels leading to PP. This study was conducted to investigate the association between exposure to phthalate esters and PP in a sample of girls. Plasma levels of seven phthalate ester metabolites were measured in 87 girls with PP and 63 age- and sex-matched controls by dispersive liquid–liquid microextraction and GC/MS analysis. History of exposure to main sources of phthalates was obtained by a checklist. Diethyl hexyl phthalate (DEHP) metabolite levels were significantly higher in those with PP than that in controls (p < 0.05), but this difference was not significant for other phthalate metabolites. 30.1% girls with PP and 12.2% of controls had played for more than 2 h/day with plastic toys in their childhood. 65.1% girls with PP and 32.8% of controls have regularly used some cosmetic products. Consumption of bottled water and beverages by those with PP was about twofold higher than that in the control group. A positive correlation was found between bottled ware consumption and plasma concentrations of four phthalate metabolites. The frequency of seafood consumption was not significantly different between the groups studied. Our findings confirm positive association between phthalate exposure and incidence of PP in girls. Control and reduction of children exposure to phthalate esters should be considered as a health priority.
Mostrar más [+] Menos [-]Interaction of pesticides with natural and synthetic solids. Evaluation in dynamic and equilibrium conditions Texto completo
2018
Otalvaro, JuliánOrtiz | Brigante, Maximiliano
Interactions between pesticides (paraquat, glyphosate, 2,4-D, atrazine, and metsulfuron methyl) and soil organic and inorganic components have been studied in batch experiments by performing adsorption, dissolution, and chemical and photochemical degradation under different conditions. The obtained results confirm that the affinity of a pesticide to the solid surface depends on the nature of both and shows that each reactant strongly affects the mobility of the other one, e.g., anionic pesticides promote the dissolution of the solid humic acid but if this last is retained into the inorganic matrix enhances the adsorption of a cationic pesticide. Adsorption also seems to protect the bonded specie to be chemical degraded, such as shown in two pesticide/clay systems at constant pH. The use of mesoporous silicas could result in a good alternative for pesticide remediation. In fact, the solid shows high adsorption capacity towards paraquat and its modification with TiO₂ nanoparticles increases not only the pesticide adsorption but also seems to catalyze its degradation under UV light to less-toxic metabolites. UV-VIS spectroscopy was relevant and novel in such sense. Electrostatic interactions, hydrogen and coordinative bonds formations, surface complexations and hydrophobic associations play a key role in the fate of mentioned pesticides on soil and ground/surface water environments.
Mostrar más [+] Menos [-]Antifungal exploitation of fungicides against Fusarium oxysporum f. sp. capsici causing Fusarium wilt of chilli pepper in Pakistan Texto completo
2018
Bashir, MuhammadRizwan | Atiq, Muhammad | Sājid, Muḥammad | Mohsan, Muhammad | Abbas, Waseem | Alam, MuhammadWaqar | Bashair, Muhammad
The research was conducted to evaluate in-vitro efficacy of numerous fungicides against Fusarium oxysporum f. sp. capsici. In present research, six treatments (T) viz. Carbendazim, Benomyl, Topsin-M, Difenoconazole, Nativo, and Alliete along with control, various concentrations (C), days (D), and their interactions, i.e., (T × C), (T × D), (C × D), and (T × C × D) were exploited in a laboratory through food poison technique. Alliete expressed maximum colony growth (1.93 cm) as compared to all other fungicides with respect to control. Interaction between treatments and concentration (T × C) exhibited maximum colony growth of all treatments (Carbendazim, Benomyl, Topsin-M, Difenoconazole, Nativo, and Alliete), i.e., 0.87, 1.23, 1.73, 2.20, 2.53, and 2.93 cm at 300 ppm as compared to 500 and 700 ppm concentrations, respectively. Similar trend was also observed concerning interaction between (fungicides × days) and (tested concentrations × days). Results of the present study revealed that among tested fungicides, Carbendazim at 700 ppm expressed significant reduction in fungal growth.
Mostrar más [+] Menos [-]Analysis method for PCBs in reclaimed oil using a fast-GC triple stage quadrupole mass spectrometer with the 13-component quantitation method Texto completo
2018
Takakuwa, Hiroshi | Miura, Takashi | Matsumura, Toru | Hashi, Norie | Kubota, Michiyo | Kutsukake, Hiroshi | Muramatsu, Kazuhiro | Kasamatsu, Takashi | Okuda, Masahiro
It is necessary for companies supplying reclaimed oil to analyze polychlorinated biphenyls (PCBs), because there is a possibility of the presence of contaminants due to trace-level PCBs in the reclaimed oil. However, common analysis methods of PCBs are time-consuming and complicated. Fast-GC triple stage quadrupole mass spectrometer with the 13-component quantitation method is an official method for analyzing PCBs in insulating oil in Japan. This method is extremely fast and simplified. The purpose of this study involves an investigation of the aforementioned fast and simple method for potential use in the analysis of reclaimed oil. Furthermore, it was attempted to combine the method with sample preparation involving only hexane dilution. The effect of sample dilutions corresponding to 100, 300, and 500 times was evaluated for reducing the matrix effect. The matrix effect was suppressed at a dilution ratio equal to or exceeding 300 times. Calibration curves of four points, namely 0.01, 0.05, 0.1, and 0.5 ng/mL, (ignored origin) by using an internal standard method were prepared for the 13 components. The square of regression coefficient (R²) values of all calibration curves exceeded 0.997. This method was adopted for the analysis of reclaimed oil containing 0.5 μg/mL PCBs, which corresponds to the judgment criteria, and accurate quantitation (accuracy value, 94.0–102%) and good repeatability (%RSD, 3.6%) were obtained. Furthermore, the required sensitivity was maintained even when 800 samples were analyzed without a cleaning ion source and an exchanging analysis column.
Mostrar más [+] Menos [-]Enhanced adsorption of uranium by modified red muds: adsorption behavior study Texto completo
2018
Wu, Wanying | Chen, Diyun | Li, Jinwen | Su, Minhua | Chen, Nan
Uranium is a hazardous and radioactive element. Effective removal of uranium from wastewater stream requires advanced functional materials and reliable technologies. Red mud is a type of low-cost adsorbent which is widely used in the adsorption process. In the present work, we successfully modified the raw red mud to gain a series of highly efficient sorbents for uranium removal. They are nitric acid dealkalized red mud (DRM), aluminum nitrate modified red mud (ARM), and ferric nitrate modified red mud (FRM). The adsorption efficiencies of uranium(VI) by DRM, ARM, and FRM were 74.50, 95.56, and 98.75% in their optimal immobilization regions, respectively. The chemisorption of uranium dominates the adsorption process of FRM, while as to physical adsorption dominates the adsorption process of ARM and DRM. Both DRM and ARM reached their maximum adsorption capacities at 10 min while that for FRM occurred at 30 min. FRM performed much stronger anti-interference ability to the influence of carbonate and calcium. The outstanding adsorption ability of these modified red muds is mainly due to the enhancement of ion exchange, co-precipitation, and electrostatic attraction by red mud’s active components and functional groups.
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