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Monitoring and risk assessment of tepraloxydim in banana (Musa paradisiaca) and sweet orange (Citrus sinensis) Texte intégral
2020
Lim, Sung-Jin | Jeong, Du-Yun | Jin, Yong-Duk | Ro, Jin-Ho
This study was conducted to analyze the residue levels of tepraloxydim in banana and sweet orange. Successive liquid–liquid extraction and cartridge clean-up method for tepraloxydim determination in banana and sweet orange were developed and validated by HPLC. The developed method was validated, and the recovery and LOQ of tepraloxydim were 79.3–99.5% and 0.02 mg kg⁻¹, respectively. Among the 48 banana and 34 sweet orange samples, tepraloxydim was detected in two (0.03 mg kg⁻¹) and four samples (0.03–0.05 mg kg⁻¹), respectively. A risk assessment of tepraloxydim in banana and sweet orange was conducted by calculating the percent ratio of estimated daily intake (EDI) and acceptable daily intake (ADI). The ADI of tepraloxydim was 0.05 mg kg⁻¹ day⁻¹, and the EDIs of it from banana and sweet orange were 6.3 × 10⁻⁶ and 5.1–8.5 × 10⁻⁶, respectively. The percent of EDI to ADI of tepraloxydim was 0.013 and 0.010–0.017%, respectively. These results showed that the tepraloxydim levels in this study might not be harmful to human beings.
Afficher plus [+] Moins [-]Urea application enhances cadmium uptake and accumulation in Italian ryegrass Texte intégral
2020
Ji, Shuren | Gao, Limin | Chen, Wei | Su, Jing | Shen, Yixin
Italian ryegrass (Lolium multifolorum Lam.) has a potential phytoextraction capacity for cadmium (Cd), which is considered as the most toxic heavy metal (HM) pollutant in the farmland. The promotion effect of urea application on Italian ryegrass growth has been clarified, while it is not clear whether and how urea application affects Cd accumulation in Italian ryegrass under Cd stress. A 2-year pot experiment was conducted to investigate the effect of urea application on Cd accumulation and related mechanisms by uptake inhibition and kinetics experiments. The results showed that both shoot biomass and Cd concentration under Cd stress were increased by up to 213.37% and 84.74% in 2016 and 38.15% and 47.11% in 2017 after urea application, respectively. The shoot Cd accumulation reached maximum value (910.23 and 630.09 μg pot⁻¹ in 2016 and 2017, respectively) at the level of 300 kg ha⁻¹ urea. Superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activities were significantly increased by urea application. Compared with control group, urea application significantly improved inhibition ratio of 2, 4-dinitrophenol (DNP) rather than LaCl₃ and Ca²⁺. Cadmium uptake kinetics experiment showed that urea application significantly decreased the Kₘ value and improved the α value (P < 0.01), but no significant effect on the Vₘₐₓ value (P > 0.05). In conclusion, we proposed that the higher affinity to Cd²⁺ of the membrane transporter after urea application promoted the active uptake of Cd, which contributed to the effective Cd accumulation capacity in Italian ryegrass.
Afficher plus [+] Moins [-]Hepatoprotective role of berberine against paraquat-induced liver toxicity in rat Texte intégral
2020
Eftekhari, Aziz | Hasanzadeh, Amir | Khalilov, Rovshan | Hosainzadegan, Hasan | Ahmadian, Elham | Eghbal, Mohammad Ali
Paraquat (PQ) is a herbicide agent commonly used in agricultural applications. Hepatotoxicity is among clinical complications associated with PQ intoxication. Oxidative stress and its subsequent events are major mechanisms identified in PQ-induced liver toxicity. Berberine (BBR) is a natural antioxidant widely investigated for its hepatoprotective effects. The present study designed to evaluate the potential cytoprotective properties of BBR against PQ-induced cytotoxicity in primary cultured rat hepatocytes and in vivo test of liver function enzymes. Cellular and biochemical parameters including lactate dehydrogenase (LDH), cell viability, ROS formation, glutathione (GSH) content, and mitochondrial membrane potential in the PQ-treated hepatocytes were measured, and the mentioned markers were evaluated in the presence of BBR. BBR treatment caused significant decrease in PQ-induced cell death, ROS formation, and LDH release. On the other hand, it was found that BBR inhibits cellular glutathione depletion in PQ-treated hepatocytes. Also, BBR treatment significantly diminished PQ-induced the liver function enzyme elevation. These data mention the potential hepatoprotective effect of BBR with therapeutic capability against PQ-induced liver damage.
Afficher plus [+] Moins [-]Studying of drought phenomena and vegetation trends over South Asia from 1990 to 2015 by using AVHRR and NASA’s MERRA data Texte intégral
2020
Shahzād, ʻAlī | Xu, Zhen Tian | Henchirli, Malak | Wilson, Kalisa | Zhang, Jiahua
Drought is a severe climate fact that mainly results from low rainfall leading to serious threat of water shortages an ecological system of South Asia. Due to the current drought conditions and vegetation dynamics, the situation could further be intensified over South Asia. Thus, we study the drought impacts on vegetation dynamics over South Asia, aimed to find out the spatiotemporal differences in vegetation dynamics and seasons at which vegetation is determined by drought. Our approach is based on the using of advanced very high resolution radiometer (AVHRR) normalized difference vegetation index (NDVI) data and (NASA’s MERRA) air temperature and rainfall data (1990–2015). Due to the low vegetation and dryness in South Asia, the NDVI is more helpful in describing the drought condition. From April to October, there were fast improvements in NDVI, VHI, and VCI. During September, the monthly VHI and VCI were stabilized and enhanced in October once more and in December again indicated a declining trend. The PCI, TCI, VCI, and VHI monthly values confirmed that in 2001, an extreme drought year, and continuous up to 2003, which lead the maximum drought in the South Asia regions. A considerably significantly correlation value in summer (JJA) and autumn (SON) seasons are showed between precipitation and NDVI. While the relationship between NVSWI and NDVI presented considerably high relationship in DJF, JJA, and SON, which specify an excellent indication for monitoring water stress. From 1990 to 2015, the difference of vegetation trend was obvious showed among various regions. The drought frequency was reducing trends from 1990 to 2015 over South Asia.
Afficher plus [+] Moins [-]Synthesis and characterization of high-performance activated carbon from walnut shell biomass for CO2 capture Texte intégral
2020
Al Mesfer, Mohammed K.
An increasing level of carbon dioxide (CO₂) in the atmosphere has ultimately resulted in global warming and climate change. The high-performance activated carbon (AC-WL) was synthesized from walnut shell, a low-cost biomass by-product, by physical activation using a tube furnace. The adsorption behavior of CO₂ from the CO₂/N₂ mixture was investigated using a fixed bed. The surface and morphological characterizations of the produced activated carbons were measured using a BET analyzer and a scanning electron microscope (SEM). The effect of temperature, flow rate, CO₂ level, and partial pressure on breakthrough behavior was analyzed, and the adsorption response presented in terms of breakthrough point and adsorption capacity. The breakthrough and saturation periods vary significantly with change in temperature. The steepness of the breakthrough curves signifies good utilization of adsorbent capacity at breakthrough point. The increase in temperatures and flow rates lead to an increase in the length of mass transfer zone. The adsorption capacity of 1.58 mmol/g was obtained at 1.30 bars and 293 K with higher capacity utilization factor of 0.8492.These results suggest that the walnut-based activated carbon is favorable for capturing CO₂.
Afficher plus [+] Moins [-]Groundwater pollution source apportionment using principal component analysis in a multiple land-use area in southwestern China Texte intégral
2020
Li, Qiling | Zhang, Han | Guo, Shanshan | Fu, Kang | Liao, Lei | Xu, Yi | Cheng, Siqian
Identification of different pollution sources in groundwater is challenging, especially in areas with diverse land uses and receiving multiple inputs. In this study, principal component analysis (PCA) was combined with geographic information system (GIS) to explore the spatial and temporal variation of groundwater quality and to identify the sources of pollution and main factors governing the quality of groundwater in a multiple land-use area in southwestern China. Groundwater samples collected from 26 wells in 2012 and 38 wells in 2018 were analyzed for 13 water quality parameters. The PCA results showed that the hydro-geochemical process was the predominant factor determining groundwater quality, followed by agricultural activities, domestic sewage discharges, and industrial sewage discharges. Agriculture expansion from 2012 to 2018 resulted in increased apportionment of agricultural pollution. In contrast, economic restructure and infrastructure improvement reduced the contributions of domestic sewage and industrial pollution. Anthropogenic activities were found the major causes of elevated nitrogen concentrations (NO₃⁻, NO₂⁻, NH₄⁺) in groundwater, highlighting the necessity of controlling N sources through effective fertilizer managements in agricultural areas and reducing sewage discharges in urban areas. The applications of GIS and PCA successfully identified the sources of pollutants and major factors driving the variations of groundwater quality in tested years.
Afficher plus [+] Moins [-]The reaction of cucumber to the introduction of ionic liquids into the soil Texte intégral
2020
Biczak, Robert | Pawłowska, Barbara | Podsiadło, Cezary | Śnioszek, Martyna | Telesiński, Arkadiusz
This paper presents the influence of two bromides, tetrabutylammonium and tetrabutylphosphonium, on the growth and development of cucumber seedlings. The tests were performed at two dates, i.e. 10 and 20 days, after the introduction of increasing amounts of ionic liquids (ILs) into the soil. The applied ILs showed phytotoxicity dependent mainly on the concentration of the substance, which is proved by the inhibition of the length of aboveground parts and their roots and the yield of cucumber fresh mass, from which EC₅₀ values were calculated. The phytotoxicity symptoms were the result of oxidative stress, one of the manifestations of which was a decrease in assimilative pigments, linearly correlated with an increase in bromide concentration in the medium. The stress is also proven by the large increase in hydrogen peroxide, malondialdehyde and free proline in cucumber leaves. The reaction of this plant to oxidative stress was an increase in the activity of antioxidative enzymes such as catalase and peroxidase. As a result of statistical analysis, it was proved that all changes of biomarkers of phytotoxicity of examined ILs and oxidative stress indicators in cucumber seedlings depended more on the applied concentration of these salts than on the date of the study.
Afficher plus [+] Moins [-]Prenatal exposure to organophosphate pesticides, maternal paraoxonase 1 genotype, and childhood neurodevelopment at 24 months of age in Shandong, China Texte intégral
2020
Wang, Yiwen | Zhang, Yan | Ji, Lin | Zhou, Yijun | Shi, Rong | Kamijima, Michihiro | Ueyama, Jun | Gao, Yu | Tian, Ying
Prenatal organophosphate pesticide (OP) exposure was reported to negatively affect childhood neurodevelopment. Paraoxonase 1 (PON1) is a key enzyme in the metabolism of OPs and may affect an individual’s susceptibility to OP exposure. However, little is known about its role in the associations of prenatal OP exposure and childhood neurodevelopment. We measured dimethylphosphate (DM), diethylphosphate (DE), and total dialkylphosphate (DAP) metabolites in maternal urine (n = 436) as well as PON1–₁₀₈C/T and PON1₁₉₂Q/R genotypes in maternal blood (n = 244). We assessed the modifying effects of maternal PON1–₁₀₈C/T and PON1₁₉₂Q/R genotypes on relationships between prenatal OP exposure and developmental quotients (DQs) in 24-month-old children in Shandong, China (n = 172). Among children of mothers carrying PON1–₁₀₈CC, a tenfold increase in prenatal DMs was associated with a 5.72-point decrease in social domain DQ scores. Among children of mothers carrying PON1₁₉₂QQ, a tenfold increase in prenatal DMs and DAPs were associated with a 7.68- and 7.67-point decrease in gross motor domain DQ scores, respectively. Among children of mothers carrying PON1₁₉₂QQ, a tenfold increase in prenatal DMs, DEs, and DAPs were associated with a 7.52-, 9.07-, and 9.60-point decrease in social domain DQ scores, respectively. Maternal PON1 genotype might modify the associations between prenatal OP exposure and children’s neurodevelopment at 24 months of age.
Afficher plus [+] Moins [-]Distance to landfill and human activities affects the debris incorporation into the white stork nests in urbanized landscape in central Spain Texte intégral
2020
Jagiello, Zuzanna | López-García, Alejandro | Aguirre, José I. | Dylewski, Łukasz
Human’s activities dominates many aspects of the Earth’s environment; thus animals are forced to adapt and respond to the resulting changes in habitat structure and functioning due to anthropogenic pressure. Along with the growing human population and the associated amount of waste produced, the amount of different type of physical contamination component in environment is increasing. Incorporation of debris in nests may be a mounting avian response to anthropogenic pollution. In this research, we quantified the constituent pieces and total mass of human-derived materials incorporated in white stork nests. The study was conducted on four locations in central Spain where white storks nest along a urbanization gradient. In total, we examined 49 nests. This study demonstrates that the incorporation of debris by white storks into their nests is related to human activity, measured by the Human Footprint Index (HFI). Moreover, the distance between these nests and landfills predicts the occurrence of debris incorporated into nests. Our study shows that birds nest building behaviour is impacted by human activities and pollution in environment.
Afficher plus [+] Moins [-]Testing the moderating role of urbanization on the environmental Kuznets curve: empirical evidence from an emerging market Texte intégral
2020
Kirikkaleli, Dervis | Kalmaz, Demet Beton
Over the last 50 years, urban population of Turkey has grown from 25 to 75%. Urbanization is highly linked with one of the most important global problems which is global warming through accelerating economic growth, energy consumption, and trade openness that are considered to be the main indicators of climate change in environmental literature. The main purpose of the present research is to examine the long-run effect of economic growth, energy consumption, trade openness, and urbanization on environmental degradation and causal link among the indicators under consideration in Turkey by taking into account the moderating role of urbanization over the period of 1960–2016. Aiming to establish robust findings, this study utilized both traditional and modern econometric techniques, including Bayer and Hanck cointegration, Gregory and Hansen cointegration, fully modified ordinary least squares (FMOLS) and dynamic ordinary least square (DOLS), Granger causality, Toda-Yamamoto causality, and Gradual Shift causality tests. The cointegration tests reveal that carbon dioxide (CO₂) emissions and economic growth, energy consumption, trade openness, urbanization, and the moderating role of urbanization are cointegrated. The outcomes of the long-run estimators—FMOLS and DOLS—reveals that environmental Kuznets curve (EKC) hypothesis is valid and the existence of moderating role of urbanization on indicators of CO₂ emissions is confirmed for the case of Turkey. Moreover, the causality tests mirror that while energy consumption, trade openness, and urbanization are important for predicting CO₂ emissions, the moderating role of urbanization leads CO₂ emissions in the short run.
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