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Результаты 3501-3510 из 4,033
Toxic heavy metals in the muscle of roe deer (Capreolus capreolus)—food toxicological significance
2016
Lehel, József | Laczay, Péter | Gyurcsó, Adrienn | Jánoska, Ferenc | Majoros, Szilvia | Lányi, Katalin | Marosán, Miklós
The study was performed on 20 (10 males, 10 females) roe deer (Capreolus capreolus) to investigate the concentration of cadmium, lead, mercury, and arsenic in the muscle tissue. They reside in forest and meadow, about 50 km distance from industrial activities and traffic. Samples were taken from the musculus biceps femoris of each deer without external contamination after shooting during the regular hunting season on a hunting area close to Eger in Hungary. The determination of heavy metal contents was carried out by inductively coupled plasma optical emission spectrometry (ICP-OES). The statistical analysis was performed by statistical package for the social sciences (SPSS) version 11.0. The measured residue concentration of cadmium was below the limit of detection in the roe deer meat indicating no health risk for the consumers. The average lead concentration (0.48 ± 0.21 mg/kg wet weight) exceeded the regulated maximum limit, but its calculated weekly intake was below the provisional tolerable weekly intake (PTWI). The residue level of mercury is not regulated and the average mercury content of roe deer meat (0.87 ± 0.40 mg/kg wet weight) was about half of PTWI, but the consumption of meat with the highest detected concentrations results in higher PTWI than recommended. The measured concentration of arsenic (0.27 ± 0.20 mg/kg wet weight) in the roe deer meat may not pose any health risk for the human consumers according to the PTWI set by the World Health Organization.
Показать больше [+] Меньше [-]Characterization of chromophoric dissolved organic matter and relationships among PARAFAC components and water quality parameters in Heilongjiang, China
2016
Cui, Hongyang | Shi, Jianhong | Qiu, Linlin | Zhao, Yue | Wei, Zimin | Wang, Xinglei | Jia, Liming | Li, Jiming
Chromophoric dissolved organic matter (CDOM) is an important optically active substance that can transports nutrients and pollutants from terrestrial to aquatic systems. Additionally, it is used as a measure of water quality. To investigate the source and composition of CDOM, we used chemical and fluorescent analyses to characterize CDOM in Heilongjiang. The composition of CDOM can be investigated by excitation-emission matrix (EEM) fluorescence and parallel factor analysis (PARAFAC). PARAFAC identified four individual components that were attributed to microbial humic-like (C1) and terrestrial humic-like (C2–4) in water samples collected from the Heilongjiang River. The relationships between the maximum fluorescence intensities of the four PARAFAC components and the water quality parameters indicate that the dynamic of the four components is related to nutrients in the Heilongjiang River. The relationships between the fluorescence component C3 and the biochemical oxygen demand (BOD₅) indicates that component C3 makes a great contribution to BOD₅ and it can be used as a carbon source for microbes in the Heilongjiang River. Furthermore, the relationships between component C3, the particulate organic carbon (POC), and the chemical oxygen demand (CODMₙ) show that component C3 and POC make great contributions to BOD₅ and CODMₙ. The use of these indexes along with PARAFAC results would be of help to characterize the co-variation between the CDOM and water quality parameters in the Heilongjiang River.
Показать больше [+] Меньше [-]Acute and short-term developmental toxicity of cyhalofop-butyl to zebrafish (Danio rerio)
2016
Cao, Fangjie | Liu, Xiaoshan | Wang, Chengju | Zheng, Mingqi | Li, Xuefeng | Qiu, Lihong
Cyhalofop-butyl is an aryloxyphenoxypropionate post-emergence herbicide widely used around the world in agriculture. The acute toxicity of cyhalofop-butyl to embryos, larvae (12 and 72 h post-hatching), and adult zebrafish, as well as the short-term developmental toxicity of cyhalofop-butyl to embryo and sac-fry stages, was tested. The results showed that the 96-h LC₅₀ values of cyhalofop-butyl to embryos, 12 h post-hatching larvae, 72 h post-hatching larvae, and adult fish were 2.03, 0.58, 1.42, and 3.49 mg/L, respectively, suggesting zebrafish early life stages were more sensitive to cyhalofop-butyl than adult stage. Cyhalofop-butyl would inhibit the spontaneous movement, heartbeat, hatching rate of embryos, and the body length of surviving larvae of zebrafish at 1.00 mg/L or higher concentrations. Morphological abnormalities, including pericardial edema, yolk sac edema, deformation of tail, and deformation of spine, were induced by cyhalofop-butyl. The results indicated that cyhalofop-butyl had significant negative impacts on zebrafish at different life stages, and spontaneous movement and hatching rate were sensitive endpoints for assessing short-term developmental toxicity of cyhalofop-butyl.
Показать больше [+] Меньше [-]MicroRNA-1228* inhibit apoptosis in A549 cells exposed to fine particulate matter
2016
Li, Xiaobo | Ding, Zhen | Zhang, Chengcheng | Zhang, Xin | Meng, Qingtao | Wu, Shenshen | Wang, Shizhi | Yin, Lihong | Pu, Yuepu | Chen, Rui
Studies have reported associations between fine particulate matter (PM₂.₅) and respiratory disorders; however, the underlying mechanism is not completely clear owing to the complex components of PM₂.₅. microRNAs (miRNAs) demonstrate tremendous regulation to target genes, which are sensitive to exogenous stimulation, and facilitate the integrative understood of biological responses. Here, significantly modulated miRNA were profiled by miRNA microarray, coupled with bioinformatic analysis; the potential biological function of modulated miRNA were predicted and subsequently validated by cell-based assays. Downregulation of miR-1228-5p (miR-1228*) expression in human A549 cells were associated with PM₂.₅-induced cellular apoptosis through a mitochondria-dependent pathway. Further, overexpression of miR-1228* rescued the cellular damages induced by PM₂.₅. Thus, our results demonstrate that PM₂.₅-induced A549 apoptosis is initiated by mitochondrial dysfunction and miR-1228* could protect A549 cells against apoptosis. The involved pathways and target genes might be used for future mechanistic studies.
Показать больше [+] Меньше [-]Toxicity assessment of silver nanoparticles in Persian sturgeon (Acipenser persicus) and starry sturgeon (Acipenser stellatus) during early life stages
2016
Banan, Ashkan | Kalbassi Masjed Shahi, Mohammad Reza | Bahmani, Mahmoud | Yazdani Sadati, Mohammad Ali
Silver nanoparticles (AgNPs) are widely used in consumer products mainly due to their antimicrobial action. The rapidly increasing use of nanoparticles (NPs) has driven more attention to their possible ecotoxicological effects. In this study, the acute toxicity of colloidal AgNPs was evaluated during the embryonic stage of Persian sturgeon (Acipenser persicus) and starry sturgeon (Acipenser stellatus) at concentrations of 0, 0.25, 0.5, 1, 2, 4, and 8 mg/L. Fertilized eggs (75 eggs per replicate) were exposed to aforementioned concentrations for 96 h in triplicate. 96-h LC50 values in Persian sturgeon and starry sturgeon were calculated as 0.163 and 0.158 mg/L, respectively. Furthermore, in starry sturgeon, the short-term effects of AgNPs on the hatching rate, survival rate, and Ag accumulation during early life stages (before active feeding commences) were also analyzed at concentrations of 0, 0.025, 0.05, and 0.1 mg/L of colloidal AgNPs. The highest silver accumulation occurred in larvae exposed to 0.1 mg/L AgNPs; however, the body burden of silver did not alter survival rate, and there were no significant differences among treatments. Based on the obtained results from the acute toxicity exposures, AgNPs induced a concentration-dependent toxicity in both species during early life stages, while complementary studies are suggested for investigating their short-term effects in detail.
Показать больше [+] Меньше [-]Performance analysis and optimization of an advanced pharmaceutical wastewater treatment plant through a visual basic software tool (PWWT.VB)
2016
Pal, Parimal | Thakura, Ritwik | Chakrabortty, Sankha
A user-friendly, menu-driven simulation software tool has been developed for the first time to optimize and analyze the system performance of an advanced continuous membrane-integrated pharmaceutical wastewater treatment plant. The software allows pre-analysis and manipulation of input data which helps in optimization and shows the software performance visually on a graphical platform. Moreover, the software helps the user to “visualize” the effects of the operating parameters through its model-predicted output profiles. The software is based on a dynamic mathematical model, developed for a systematically integrated forward osmosis-nanofiltration process for removal of toxic organic compounds from pharmaceutical wastewater. The model-predicted values have been observed to corroborate well with the extensive experimental investigations which were found to be consistent under varying operating conditions like operating pressure, operating flow rate, and draw solute concentration. Low values of the relative error (RE = 0.09) and high values of Willmott-d-index (d wᵢₗₗ = 0.981) reflected a high degree of accuracy and reliability of the software. This software is likely to be a very efficient tool for system design or simulation of an advanced membrane-integrated treatment plant for hazardous wastewater.
Показать больше [+] Меньше [-]Characterization, chemometric evaluation, and human health-related aspects of essential and toxic elements in Italian honey samples by inductively coupled plasma mass spectrometry
2016
Quinto, Maurizio | Miedico, Oto | Spadaccino, Giuseppina | Paglia, G. (Giuseppe) | Mangiacotti, Michele | Li, Donghao | Centonze, Diego | Chiaravalle, A Eugenio
Concentration values of 24 elements (Al, As, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, Ge, Hg, Mn, Mo, Pb, Sb, Se, Sn, Sr, Ti, Tl, U, V, and Zn) were determined in 72 honey samples produced in Italy by inductively coupled plasma mass spectrometry (ICP-MS). Considering the recommended established heavy metal daily intakes for humans, in this perspective, an equilibrated and ordinary honey consumption should not be considered matter of concerns for human health, even if particular attention should be addressed if honey is consumed by children, due to different maximum daily heavy metal intakes. Chemometric analysis of the results obtained highlights heavy metal content differences in honey samples obtained from notoriously polluted zones, confirming then that honey can be considered a bio-indicator of environmental pollution. Finally, Pearson coefficients highlighted correlations among element contents in honey samples.
Показать больше [+] Меньше [-]Measurement of p-nitrophenyl acetate esterase activity (EA), total antioxidant capacity (TAC), total oxidant status (TOS) and acetylcholinesterase (AChE) in gills and digestive gland of Mytilus galloprovincialis exposed to binary mixtures of Pb, Cd and Cu
2016
Franco-Martinez, Lorena | Romero, Diego | García-Navarro, José A. | Tecles, Fernando | Teles, Mariana | Tvarijonaviciute, Asta
The aims of the present work were (1) to evaluate oxidative stress biomarkers and AChE in two tissues of wild mussel (Mytilus galloprovincialis) of high biochemical activity and accumulation capacity (gills and digestive gland) and (2) to study the behaviour of these biomarkers in presence of heavy metals. For this, EA, TOS, TAC and AChE were measured in tissues of mussels exposed to binary combination of Pb, Cd and Cu. Mussels (n = 36) were exposed to one of the binary mixtures of Pb (1000 μg L⁻¹), Cd (100 μg L⁻¹) and Cu (100 μg L⁻¹) for 7 days, under controlled conditions. Gills and digestive gland were extracted and frozen at −80 °C until analysis. The automatic methods employed for the measurement of EA, TAC, TOS and AChE in M. galloprovincialis revealed higher levels of these biomarkers in digestive gland than gills. Study results suggest that gills would be the tissue of election for study oxidative stress markers, whereas digestive tissue should be selected for AChE measurements in case of evaluation of combined metal toxicity in mussels.
Показать больше [+] Меньше [-]Comparative effects of direct-fed microbials alone or with a trace minerals supplements on the productive performance, blood metabolites, and antioxidant status in grazing Awassi lambs
2016
Alhidary, I. A. | Abdelrahman, M. M. | Khan, R. U.
Twenty Awassi lambs were used to find the effects of direct-fed microbials (DFM) and long-acting trace minerals rumen bolus (TMB) supplements on performance, blood biochemical variables, and antioxidant status of the lambs under grazing conditions. The lambs were randomly distributed into four groups as follows: (1) untreated, (2) oral dose of 5 mL DFM, (3) TMB, or (4) oral dose of 5 mL DFM and TMB. The treatments were carried out for 90 days. Supplementation with TMB significantly increased (P < 0.05) average daily gain (ADG) and feed efficiency compared with the control. A significant (P < 0.05) increase in blood albumin in the DFM and a significant (P < 0.05) decrease in aspartate aminotrasferase were found in the lambs supplemented with TMB alone or in combination with DFM. Supplementing lambs with TMB resulted in higher glutathione peroxidase, total antioxidant capacity (P < 0.001) and activity of superoxide dismutase (P < 0.05) compared with no supplementation and supplementation with DFM only. In conclusion, TMB supplementation had a positive impact on performance traits and the antioxidant system of the lambs under grazing condition.
Показать больше [+] Меньше [-]Modeling the feedback between aerosol and boundary layer processes: a case study in Beijing, China
2016
Miao, Yucong | Liu, Shuhua | Zheng, Yijia | Wang, Shu
Rapid development has led to frequent haze in Beijing. With mountains and sea surrounding Beijing, the pollution is found to be influenced by the mountain-plain breeze and sea-land breeze in complex ways. Meanwhile, the presence of aerosols may affect the surface energy balance and impact these boundary layer (BL) processes. The effects of BL processes on aerosol pollution and the feedback between aerosol and BL processes are not yet clearly understood. Thus, the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) is used to investigate the possible effects and feedbacks during a haze episode on 23 September 2011. Influenced by the onshore prevailing wind, sea-breeze, and upslope breeze, about 45 % of surface particulate matter (PM)₂.₅ in Beijing are found to be contributed by its neighbor cities through regional transport. In the afternoon, the development of upslope breeze suppresses the growth of BL in Beijing by imposing a relatively low thermal stable layer above the BL, which exacerbates the pollution. Two kinds of feedback during the daytime are revealed as follows: (1) as the aerosols absorb and scatter the solar radiation, the surface net radiation and sensible heat flux are decreased, while BL temperature is increased, resulting in a more stable and shallower BL, which leads to a higher surface PM₂.₅ concentration in the morning and (2) in the afternoon, as the presence of aerosols increases the BL temperature over plains, the upslope breeze is weakened, and the boundary layer height (BLH) over Beijing is heightened, resulting in the decrease of the surface PM₂.₅ concentration there.
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