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Результаты 4691-4700 из 6,535
Changes of various insecticides during in vitro human digestion Полный текст
2020
Kim, Hyeong Sang | Yi, Sŭng-yun | Hur, Sun Jin
This study was performed to determine the effects of in vitro human digestion on the concentrations of five insecticides, namely 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT), 1,1-dichloro-2,2-bis(p-chlorophenyl)ethane (DDD), 2,2-bis(p-chlorophenyl)-1,1-dichloroethylene (DDE), bifenthrin, and fipronil. In vitro models included all the steps of human digestion, i.e., passage through the mouth, stomach, small intestine, and large intestine (with enteric bacteria). The concentrations of DDT and fipronil did not change (P > 0.05) until small intestinal digestion, whereas those of DDD, DDE, and bifenthrin decreased (P < 0.05) at each digestion step. The concentrations of all the insecticides decreased (P < 0.05) during the large intestinal digestion step with enteric bacteria, Lactobacillus sakei and Escherichia coli. In conclusion, the concentrations of all the tested insecticides decreased during all the steps of in vitro human digestion and were especially reduced by enteric bacteria during the large intestinal digestion step.
Показать больше [+] Меньше [-]Chemical characterization, phytotoxic, and cytotoxic activities of essential oil of Mentha longifolia Полный текст
2020
Singh, Narayan | Singh, Harminder Pal | Batish, Daizy Rani | Kohli, Ravinder Kumar | Yadav, Surender Singh
The present study assessed the phytotoxic and cytotoxic potential of the essential oil (EO) extracted from aboveground parts of Mentha longifolia (L.) Huds. Gas chromatography–mass spectrometry revealed 39 compounds constituting 99.67% of the EO. The EO was rich in monoterpenoids (mostly oxygenated monoterpenes), which accounted for 89.28% of the oil. The major components in EO were monoterpene ketones such as piperitone oxide (53.83%) and piperitenone oxide (11.52%), followed by thymol (5.80%), and (E)-caryophyllene (4.88%). The phytotoxic activities of EO were estimated against Cyperus rotundus, Echinochloa crus-galli, and Oryza sativa (rice) through pre- and post-emergence assays at concentrations ranging from 10 to 250 μg/ml and 0.5–5%, respectively. In pre-emergence assay, the phytotoxic effect of EO was most pronounced on C. rotundus, thereby significantly affecting percent germination, plantlet growth, and chlorophyll content. On the contrary, the impact was comparatively lesser on rice, with ~ 40% germination in response to 250 μg/ml of EO treatment. In the post-emergence assay, the spray treatment of EO caused a loss of chlorophyll and wilting in test plants, and subsequently affected the growth of plants, even leading to death in some cases. The cytotoxic activity of EO (at 2.5–50 μg/ml) was studied in meristem cells in onion (Allium cepa L.) root tips. EO exposure to the onion roots induced various chromosomal aberrations such as chromosomal bridges, c-mitosis, stickiness, vagrant chromosomes, etc., and negatively affected the mitotic index. At 50 μg/ml, EO treatment triggered the complete death of roots. The study concludes that M. longifolia EO has phytotoxic activities due to the mito-depressive effect, along with other physiological effects on target plants. Therefore, EO of M. longifolia could be developed into a novel bioherbicide for sustainable management of weeds in agricultural systems.
Показать больше [+] Меньше [-]Arsenic, cadmium, mercury, and lead levels in hair and urine in first-year RUDN University students of different geographic origins Полный текст
2020
Kirichuk, Anatoly A. | Skalny, Andrey A. | Rusakov, Alexander I. | Tinkov, Alexey A. | Skalny, Anatoly V.
The objective of the present study was to assess the markers of arsenic, cadmium, mercury, and lead exposure in first-year RUDN University students of different geographic origins. A total of 274 first-year students of the RUDN University originating from Russia (n = 65), Asia (n = 57), Middle East (n = 84), Africa (n = 40), and Latin America (n = 28) were enrolled in the present study. Evaluation of As, Cd, Hg, and Pb levels in urine and hair was performed using inductively coupled plasma-mass spectrometry. The obtained data demonstrate that hair As levels in foreign students exceed that in Russian examinees. The highest Cd and Pb levels were detected in subjects from Africa and Latin America, whereas hair Hg content was significantly higher in Latin America students. Urinary Cd levels in foreign students exceeded those in Russian counterparts. In turn, the highest Hg concentration in urine was revealed in students originating from Middle East and especially Latin America. Urinary Pb levels were found to be the highest in students from Africa. Multiple regression analysis demonstrated that Asian, African, and Latin American origins were considered as a significant predictor of hair Hg content. Higher urinary Hg levels were associated with Asia, Middle East, and Latin American origins. Prior habitation in Africa and Asia was considered as predictor of higher hair Pb and urinary Cd levels. The observed difference may be indicative of geographic difference in toxic metal exposure patterns.
Показать больше [+] Меньше [-]A novel modeling approach for a generalizable photo-Fenton-based degradation of organic compounds Полный текст
2020
Audino, Francesca | Pérez-Moya, Montserrat | Graells, Moisès | Espuña, A. | Csukás, Béla | Varga, Mónika
This work aims at proposing and validating a model that can be exploited for the future development of industrial applications (e.g., process design and control) of Fenton and photo-Fenton processes. Hence, a compromise modeling solution has been developed between the non-generalizable accuracy of the first principles models (FPMs) and the oversimplification of the empirical models (EMs). The work presents a novel model of moderate complexity that is simplified enough to be generalizable and computationally affordable, while retaining physical meaning. The methodology is based on a general degradation mechanism that can be algorithmically generated from the carbon number of the target compound, as well as from the knowledge of two kinetic parameters, one for the faster initial rate and the other one for the subsequent degradation steps. The contaminant degradation mechanism has been combined with an appropriately simplified implementation of the well-known Fenton and photo-Fenton kinetics. This model describes the degradation not only of the target compound and of the oxidant, but also of total organic carbon (TOC), which is used to define the overall quality of the water. Experimental design techniques were used along with a non-conventional modeling methodology of programmable process structures (PPS). This novel modeling approach was applied and validated on the degradation of three model compounds. A successful prediction of the evolution of the contaminants H₂O₂ and TOC was confirmed and assessed by the root mean square error (RMSE).
Показать больше [+] Меньше [-]Characterization of a mine legacy site: an approach for environmental management and metals recovery Полный текст
2020
Dinis, Maria de Lurdes | Fiúza, António | Futuro, Aurora | Leite, Alexandre | Martins, Diogo | Figueiredo, Janine | Góis, Joaquim | Vila de Gerlic, María Cristina
The characterization of historical mine tailings provides important information for land-management decisions, in particular when considering potential reprocessing activities or the development of an environmental protection program. In addition, outcomes from such characterization may define the scope for a more detailed investigation. The present work describes the characterization of the waste material from the Cabeço do Pião tailings impoundment performed within the project ReMinE: Improve Resource Efficiency and Minimize Environmental Footprint. The purpose of the work was to investigate alternative mine waste management options such as the extraction of valuable resources from an environmental liability. The study involved the collection of 41 samples at different locations at two different depths, physical and chemical characterization of the wastes, natural leaching tests, and potential for acid generation. The results showed that, apart from the potential instability of the dyke (with an average slope of 35°), the drained solutions flowing by percolation contain very small particles with high arsenic contents that are being incorporated into the river sediments. In addition, these very fine-grained materials are available for the transport by the wind creating secondary sources of environmental contamination. This data is fundamental for economic and environmental assessment of the two main alternatives, reprocessing or removal.
Показать больше [+] Меньше [-]Revisiting the role of forestry, agriculture, and renewable energy in testing environment Kuznets curve in Pakistan: evidence from Quantile ARDL approach Полный текст
2020
Aziz, Noshaba | Sharif, Arshian | ʻAlī, Raz̤ā | Rong, Kong
This paper assesses the Environmental Kuznets curve based on quantile behavior of the relationship between economic growth, forest area, agriculture production, renewable energy, and environmental degradation. The current literature generally used a single indicator to address environmental issues; however single indicator neither measures overall environmental conditions nor does specify that the environment issue is generally diminishing. Our study is the first one that used ecological footprint (EF) as an indicator to test environmental Kuznets curve (EKC) hypothesis for Pakistan by employing recent approach of quantile autoregressive distributed lag (QARDL) initiated by Cho et al. (J Econ 188(1):281–300, 2015). The result of this study validates the EKC hypothesis for Pakistan and shows quantile-dependent relationship, and in that case, using the conventional methods may somewhat lead to biased results. Moreover, the rejection of the null hypothesis of parameter constancy is also confirmed by Wald test. In the long run, the findings of renewable energy consumption and forest area show significant negative effects on ecological footprints, which indicates that by increasing renewable energy usage and forest area, ecological footprints can be minimized. Interestingly, the short-term effects of agricultural production findings on EF show statistically negative results. This illustrates that EF can also be reduced in the agriculture sector by adopting environment-friendly technologies. In order to create efficient policies for environment deterioration, the empirical findings of the current analysis can be used as a guideline for policy implications.
Показать больше [+] Меньше [-]Impact of green finance on economic development and environmental quality: a study based on provincial panel data from China Полный текст
2020
Zhou, Xiaoguang | Tang, Xinmeng | Zhang, Rui
The goal of green finance is to pursue the coordinated development of financial activities, environmental protection, and ecological balance. This study aims to examine the impact of green finance on economic development and environmental quality. Data concerning green finance, economic development, and environmental quality for 30 provinces and municipalities in China from 2010 to 2017 are used. First, the global principal component analysis is adopted to develop a green finance development index. Second, a model of the impact of green finance on economic development is constructed, which indicates that the development of green finance plays a role in promoting economic development. Next, emissions of industrial smoke (powder) dust, industrial solid waste, and carbon dioxide are used to represent the environmental variables, and a model of the impact of green finance on environmental quality is proposed. The model shows that green finance has a positive effect on environment improvement. However, the impact of green finance on environmental quality varies for different levels of economic development. Finally, based on the theory of the environmental Kuznets curve, a model of the impact of green finance on the relationship between economic development and environmental quality is developed. The model indicates that green finance can significantly improve this relationship, creating a win-win situation regarding economic development and the environment.
Показать больше [+] Меньше [-]Levels and distribution of polybrominated diphenyl ethers in humans and environmental compartments: a comprehensive review of the last five years of research Полный текст
2020
Klinčić, Darija | Dvoršćak, Marija | Jagić, Karla | Mendaš, Gordana | Herceg Romanić, Snježana
Polybrominated diphenyl ethers (PBDEs) are a class of brominated flame retardants (BFRs), present in the environment, animals, and humans. Their levels, distribution, and human exposure have been studied extensively, and over the last decade, various legal measures have been taken to prohibit or minimize their production and use due to the increasing amount of evidence of their harmful effects on human and animal health.Our aim here was to make a comprehensive and up-to-date review of the levels and distribution of PBDEs in the aquatic environment, air, and soil, in indoor dust, and in humans. To fulfill this, we searched through Web of Science for literature data reported in the last five years (2015–2019) on levels of at least six key PBDE congeners in abovementioned matrices. According to our summarized data, significant PBDE mass concentrations/fractions are still being detected in various sample types across the world, which implies that PBDE contamination is an ongoing problem. Secondary sources of PBDEs like contaminated soils and landfills, especially those with electronic and electrical waste (e-waste), represent a particular risk to the future and therefore require a special attention of scientists.
Показать больше [+] Меньше [-]Identifying modeling forms of instrument panel system in intelligent shared cars: a study for perceptual preference and in-vehicle behaviors Полный текст
2020
Yang, Hao | Zhao, Ying | Wang, Yueran
A sustainable human-machine interface design has been highlighted for shared cars which is environmentally friendly. To improve people’s perceptual, psychological, and behavioral experience in shared cars, this study revealed the relationship between modeling forms of the instrument panel and interaction performance. Modeling forms include the panel layout and the central screen installation type. After classifying existing panel layout designs into four kinds, this study relied on System Usability Scale (n = 182) to score them and clarify the usability of each kind. The one with the best usability (the symmetrical driver-oriented layout) was identified and ANOVA was used to judge the significance of the difference. Then, three central screen installation types were analyzed and sorted by means of analytic hierarchy process. Based on the above analysis for perceptual preference, behavioral experiments were carried out (n = 60) in intelligent vehicles equipped with the two advantageous screens (all-in-one type and semi-detached type) to analyze electrocardiograph data and workload of typical interaction behaviors. The logit model showed that when interacting with the SD-AIO panel (the panel of symmetrical driver-oriented layout with an all-in-one type screen), tension level was often lower in both driving and secondary tasks. Besides, we explored how the heart rate of specific tasks influenced the total completion time. The conclusion confirmed the advantages of SD-AIO panel, which could contribute to a sustainable interaction with high traffic efficiency.
Показать больше [+] Меньше [-]Short-term impacts of biochar, tillage practices, and irrigation systems on nitrate and phosphorus concentrations in subsurface drainage water Полный текст
2020
Farahani, Saeid Shahvarooghi | Asoodar, Mohammad Amin | Moghadam, Bijan Khalili
Leaching of nitrogen (N) and phosphorus (P) from agricultural lands can cause serious environmental problems such as eutrophication. The objective of this study was to investigate the impacts of biochar application, tillage practices, and irrigation systems on nitrate and dissolved phosphorus (DP) concentrations in subsurface drainage water and grain yield of winter wheat using a strip-split plot design with 3 replications. Irrigation at three different levels (flood (Ifₗ), furrow (Ifᵤ), and sprinkler (Iₛ) systems) considered as main factor, tillage at two levels (reduced tillage (Tᵣ) and conventional systems (Tc)) as subplot factor, and bagasse biochar at two levels (without biochar (B₀) and 20 ton ha⁻¹ biochar (B₁)) as sub-subplot factor. Polyvinyl chloride (PVC) standpipes were used in each sub-subplot to collect leachate water at 100-cm depth. The results indicated that irrigation had significant effects on yield, collected water volume (CWV), nitrate, and DP concentrations (P < 0.01). Interaction of tillage and irrigation was significant for grain yield (P < 0.05). Biochar application only caused a significant decrease in nitrate concentration under sprinkler irrigation (P < 0.05), while no significant impact was observed under flood and furrow irrigation systems. Under sprinkler irrigation, the total nitrate collected in the PVC standpipes decreased by 37.51 and 34.29% compared with flood and furrow irrigations, respectively. Biochar application reduced the total nitrate collected by 16.84%, while difference among tillage treatments was negligible (4.51%). The total DP collected under sprinkler irrigation was lower in comparison with flood and furrow irrigations by 42.24 and 38.76%, respectively. Biochar application reduced the total DP collected by 10.84%, while reduced tillage increased the total DP collected by 8.90% compared with the conventional tillage.
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