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Результаты 3831-3840 из 4,938
Overexpression of AtAAP1 increased the uptake of an alanine-chlorantraniliprole conjugate in Arabidopsis thaliana Полный текст
2019
Ren, Zhanfu | Chen, Zhiting | Luo, Xiao | Su, Jiebing | Yao, Guangkai | Xu, Hanhong | Lin, Fei
Transporters play an important role in the uptake and redistribution of agrochemicals to the site of insect feeding. The product of the Arabidopsis thaliana gene AtAAP1 substantially contributes to inorganic nitrogen acquisition under ecologically relevant amino acid concentrations. Here, the transporter ability of AtAAP1 to a chlorantraniliprole-alanine conjugate (CAP-Ala-1) was tested both in planta and in vitro. Thirty-day-old and 15-day-old plants overexpressing AtAAP1 increased the uptake of CAP-Ala-1 into the roots, whereas AtAAP1 deficiency did not completely block the uptake of CAP-Ala-1. An uptake experiment carried out in Xenopus laevis oocytes expressing AtAAP1 showed that CAP-Ala-1 interacted with AtAAP1. Although little native AtAAP1 transcription was present in the leaves, constitutive expression of AtAAP1 in plants significantly increased the ability of the leaf mesophyll protoplasts to take up CAP-Ala-1. The observations supported the possibility of exploiting AtAAP1 as a component of a novel delivery and redistribution system for amino acid-based pesticide conjugates.
Показать больше [+] Меньше [-]Toxicity of cadmium selenide nanoparticles on the green microalgaChlorella vulgaris: inducing antioxidative defense response Полный текст
2019
Movafeghi, Ali | Khataee, Alireza | Rezaee, Arezoo | Kosari-Nasab, Morteza | Tarrahi, Roshanak
Green algae are dominant primary producers in aquatic environments. Thus, assessing the influences of pollutants such as nanoparticles on the algae is of high ecological significance. In the current study, cadmium selenide nanoparticles (CdSe NPs) were synthesized using the hydrothermal method and their characteristics were determined by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FT-IR) techniques. Subsequently, the toxicity of synthesized nanoparticles on the green microalga Chlorella vulgaris was investigated. The observations by SEM confirmed that exposure to CdSe NPs had severe impacts on the algal morphology. Furthermore, the obtained results revealed the toxic effect of CdSe NPs by a decrease in the number of cells. Measurement of antioxidant enzymes activity showed an increase in the activity of catalase, and a decrease in the activity of superoxide dismutase (SOD) at high concentrations of CdSe NPs. The exposure of C. vulgaris to CdSe NPs resulted also in a change in algal pigments as well as total phenol content. Taken together, CdSe NPs appeared to have significant cytotoxic effects on C. vulgaris in the applied concentrations.
Показать больше [+] Меньше [-]Catalytic degradation of organic pollutants in Fe(III)/peroxymonosulfate (PMS) system: performance, influencing factors, and pathway Полный текст
2019
Latif, Abdul | Kai, Sun | Si, Youbin
This study demonstrated, for the first time, Fe(III)/peroximonosulphate (PMS) could be an efficient advanced oxidation process (AOP) for wastewater treatment. Bisphenol A (BPA) was chosen as a model pollutant in the present study. Fe(III)-activated PMS system proved very effective to eliminate 92.18% of BPA (20 mg/L) for 30-min reaction time at 0.50 mM PMS, 1.5 g/L Fe(III), pH 7.0. The maximum degradation of BPA occurred at neutral pH, while it was suppressed at both strongly acidic and alkaline conditions. Organic and inorganic ions can interfere with system efficiency either positively or negatively, so their interaction was thoroughly investigated. Furthermore, the presence of organic acids also affected BPA degradation rate, especially the addition of 10 mM citric acid decreased the degradation rate from 92.18 to 66.08%. Radical scavenging experiments showed that SO₄•– was the dominant reactive species in Fe(III)/PMS system. A total of 5 BPA intermediates were found by using LC/MS. A possible degradation pathway was proposed which underwent through bridge cleavage and hydroxylation processes. Acute toxicity of the BPA degradation products was assessed using Escherichia coli growth inhibition test. These findings proved to be promising and economical to deal with wastewater using iron mineral for the elimination of organic pollutants. Graphical abstract
Показать больше [+] Меньше [-]Limno-ecological assessment of Aras River surface waters in Turkey: application of diatom indices Полный текст
2019
Çelekli, Abuzer | Kayhan, Seda | Lekesiz, Ömer | Toudjani, Assane Anabi | Çetin, Tolga
This study is the first attempt to evaluate the limno-ecological status of freshwater ecosystems in Aras River system (Turkey) using diatom metrics and multivariate analyses according to the European Union Water Framework Directive requirements. Samples were collected using the standard protocols from 17 sampling stations in August and October of 2014, and June of 2015. Deterioration of water quality in the Aras River catchment was remarked from the downstream of Karakoyunlu, Sarısu, and Bozkuş creeks, which showed higher values of trophic index Turkey (TIT), trophic index (TI), and eutrophication and/or pollution index-diatom (EPI-D). These sites were also characterized by pollution tolerant taxa e.g., Cocconeis placentula, Gomphonema parvulum, Navicula cryptocephala, Navicula trivialis, and Tryblionella angustata. Sites S14–S17 had high ecological status according to TIT, supported by the score of EPI-D which indicated a good ecological condition for S14. The occurrence of pollution-sensitive species (e.g., Hannaea arcus, Cymbella affinis, Didymosphenia geminata, Meridion circulare, and Encyonema silesiacum) and the low nutrients like total phosphorus, orthophosphate and nitrate, conductivity, and BOD₅ supported the high ecological status of S14–S17. The relationships between diatom assemblages and environmental variables were also illustrated by multivariate analyses. Spearman correlation analysis revealed that TIT had positive important correlations with total phosphorus (p < 0.01, r = 0.768). Trophic index and EPI-D had also significant correlations with environmental variables, but they had lower correlation coefficient than that of TIT. It seems that TIT could be a suitable diatom metric for assessing the ecological status of sampling stations in Aras River system and Mediterranean region. Our findings showed also that ecological statuses of surface waters should be evaluated due to the indices developed in their ecoregions.
Показать больше [+] Меньше [-]Relationship among pollution concerns, attitudes toward social problems, and environmental perceptions in abandoned sites using Bayesian inferential analysis Полный текст
2019
Kim, Eujin Julia | Kang, Youngeun
How do local community perceive pollution risk and social problems in abandoned areas? Which factors affect these risk perceptions? Among several factors affecting environmental perceptions, familiarity to places has long been known to positively affect landscape perception, but is this also true for abandoned area with scruffy vegetation and industrial remnants? Will long-term residents eventually adapt to and accept these neglected landscapes? In the past, efforts have largely been devoted to the cleanup of large, highly polluted areas. This left many smaller, less polluted sites, often in urban or suburban areas, relatively neglected. These areas, which typically consist of small abandoned industrial and commercial sites and vacant lots in neighborhoods, are problematic since people living nearby continue to suffer from urban blight. Recently, there has been a shift in the focus of brownfield programs from highly polluted post-industrial cleanup to local brownfield reuse. In this new environment, a participatory planning process that engages the community seems to have become more important. In order to better understand factors affecting community people’s risk perception and effectively engage community support for the better management of derelict sites, this study investigated the factors on local community perceptions of abandoned landscapes including the effect of familiarity (the length of residency) and other sociodemographic (gender and age). For the study, the 200 study participants in eight neighborhoods along the Rail Corridor Revitalization Project in the city of Roanoke, VA, were asked to participate in survey and evaluate scenes of three types of abandoned landscapes focusing on two aspects, preference and pollution concerns. The results of scene ratings showed that lower scene preferences were associated with scene concerns related to higher pollution. However, although age and gender were associated with participants’ preference ratings and attitudes toward social problems and pollution, there was no significant effect for the length of residency.
Показать больше [+] Меньше [-]Influence of Spirulina platensis and ascorbic acid on amikacin-induced nephrotoxicity in rabbits Полный текст
2019
Abdel-Daim, Mohamed M. | Ahmed, Amira | Ijaz, Hira | Abushouk, Abdelrahman Ibrahim | Ahmed, Hussien | Negida, Ahmed | Aleya, Lotfi | Bungau, Simona G.
The current study was performed to investigate the nephroprotective efficacy of Spirulina platensis (SP) and the possible benefits of combining SP and ascorbic acid (AA) in protecting against amikacin (AMK)-induced nephrotoxicity in rabbits. Forty-two male New Zealand rabbits were allocated to seven equal groups, receiving (I) normal saline as negative controls, (II) oral SP (500 mg/kg body weight), (III) oral AA (20 mg/kg bw), (IV) intramuscular AMK injection (100 mg/kg bw), (V) AMK plus SP, (VI) AMK plus AA, or (VII) AMK plus SP and AA at the aforementioned doses. The treatments were given once/day for 7 days. Data analysis showed that in comparison to the control group, AMK-intoxicated rabbits showed significant increases (p ≤ 0.05) in serum concentrations of creatinine, uric acid, and urea, as well as renal tissue concentrations of tumor necrosis factor-α [TNF-α], malondialdehyde [MDA], and nitric oxide [NO]. Moreover, significant (p ≤ 0.05) reductions in renal glutathione concentration, antioxidant enzymatic activities (catalase, glutathione peroxidase, and superoxide dismutase), and total antioxidant capacity were noted following AMK intoxication. Treatment by SP ameliorated most of the aforementioned AMK-induced alterations. Although treatment with AA significantly reduced the renal tissue MDA, NO, and TNF-α concentrations, it was not associated with significant ameliorations of AMK-induced changes in the serum concentrations of renal function markers or renal tissue antioxidant parameters. The nephroprotective effects of SP-AA combination were more potent than SP alone in several parameters. In conclusion, SP alone or in combination with AA minimized the nephrotoxic effects of AMK through their antioxidant and anti-inflammatory activities.
Показать больше [+] Меньше [-]Genotoxic, cytotoxic, and neurotoxic responses in Anodonta cygnea after complex metal mixture treatment Полный текст
2019
Butrimavičienė, Laura | Stankevičiūtė, Milda | Kalcienė, Virginija | Jokšas, Kęstutis | Baršienė, Janina
Environmental effects associated with the release of various metals even at maximum permissible concentrations (MPC) to the aquatic ecosystems are evident. In the present work, time-dependent increase in accumulated metals amount in gills of Anodonta cygnea after exposure to complex metal (Zn 0.1, Cu 0.01, Ni 0.01, Cr 0.01, Pb 0.005, and Cd 0.005 mg/L, MPC accepted for the inland waters in EU) mixture at various time points (1, 2, 4, 7, 14, and 28 days) was investigated. Statistically significant increase of Cu and Cd was determined in mussel’s gills after 7-day exposure, in comparison to control group; moreover, significantly elevated concentration of Cu was measured and after 14-day treatment (in comparison to control and pre-exposure group). Concentrations of five (Cu, Ni, Cr, Pb, and Cd) out of 6 investigated metals were statistically increased in gills tissue after 28-day treatment. Moreover, complex metal mixture has demonstrated tissue- and time-dependent genotoxicity (∑Gentox) and cytotoxicity (∑Cytox) responses in mussels. After 4-day exposure, there were found the highest ∑Gentox levels in gills cells and haemocytes. Two-day treatment of mussels resulted in the highest and statistically significant induction of ∑Cytox level (in gills). Furthermore, after short-term (4 days) exposure, statistically significant inhibition of AChE activity in hemolymph of metal mixture–exposed mussels, in comparison to control and pre-exposure group, was found. Comparison of investigated responses in different tissue of A. cygnea discloses new information about metal mixture (at MPC) impacts at different treatment time. According to the obtained geno- and cytotoxicity data, it is suggested that gills are more sensitive tissue. Environmentally relevant trace metal concentrations when existing in mixture are able to cause adverse effects in A. cygnea; therefore, biological effects at different levels of organism are expected as a realistic scenario.
Показать больше [+] Меньше [-]Burden of disease for workers attributable to exposure through inhalation of PPAHs in RSPM from cooking fumes Полный текст
2019
Goel, Anubha | Ola, Deepshikha | Veetil, Anitha V.
Polycyclic aromatic hydrocarbons (PAHs), some of which are classified as possible carcinogens (WHO), have been detected in cooking fumes in considerable amounts. Distribution of 24 PAHs on varying particle sizes was analyzed in cooking emission. Analysis of cooking fumes from vegetarian and non-vegetarian food was carried out separately in the kitchen of a hostel mess in IIT Kanpur during November 2012 and February 2013. Respirable suspended particulate matter (RSPM) and particle-bound polycyclic aromatic hydrocarbons (PPAHs) showed a similar sequence regarding concentration observed in vegetarian and non-vegetarian food. PAHs with carcinogenic potential was detected and quantified mostly in the fine particles. Total PAH concentrations in the fine and ultrafine ranges together accounted for > 90% of the total carcinogenic PAHs, highlighting them as primary carriers of PAHs rather than coarser particles. Benzo [a] pyrene (B [a]P) levels contribute > 70% to total carcinogenic potential and > 60%, to mutagenic potential, respectively. The total toxicity impact on the workers due to the PAHs emitted from cooking fumes was 3.374 × 10⁻¹⁰ DALYs, with B [a] P contributing the most (> 70%) despite its low concentration. Exposure to cooking fumes especially for people involved in this activity on a daily basis (chefs, hostel mess workers, among others) raises health concerns. An extensive examination of impacts due to exposure to emissions in both particle and gas phase on a long-term basis is required.
Показать больше [+] Меньше [-]What matters for environmental quality in the Next Eleven Countries: economic growth or income inequality? Полный текст
2019
Padhan, Hemachandra | Haouas, Ilham | Sahoo, Bhagaban | Heshmati, Almas
This study uses panel data for the period 1971–2013 to explore the implications of growth, wealth disparities, and per capita energy consumption on carbon emissions in a sample of Next Eleven (N-11) countries. It uses the first-generation (Pedroni and Kao) and second-generation (Westerlund) cointegration techniques to highlight a long-run interplay between the selected variables in carbon emission functions for all the N-11 countries. It also analyzes the long-run interactions among the series. Contrastingly, it also shows that economic growth, income inequalities, and per capita energy consumption accelerate CO₂ emissions. Besides examining the effects of wealth disparity square, the study also uses the environmental Kuznets curve hypothesis in the context of the N-11 countries and discusses the policy implications of its findings.
Показать больше [+] Меньше [-]Knowledge and behavior regarding pesticide use: a survey among caregivers of children aged 1–6 years from rural China Полный текст
2019
Deng, Yuanying | Dai, Hongmei | Zeng, Ming | Guan, Lan | Luo, Xiangwen | Zhang, Chen | Tian, Jing | Zhang, Jie | Li, Ying | Xi, Qiong | Zhao, Mengwen | Jiang, Mei | Zhao, Lingling
Little is known about pesticide exposure risks for children in rural areas in China, many of whom have been left behind by migrant workers. To survey caregivers of children in rural China and assess their pesticide use and disposal methods, the measures were used to protect the children and their perceptions of the adverse effects of pesticides on children’s health. Three or four villages in each of Xinhua, Gongan and Sansui Counties in China were selected by random cluster sampling. The main caregivers of children aged 1–6 years were surveyed in face-to-face interviews. The questionnaire used was adapted from the World Health Organization “Exposure to Pesticides: Standard Protocol” survey and similar studies. The study included 464 caregivers (mean age, 46.4 years), who were most commonly the children’s grandparents (65.3%). Among the caregivers, 41.9% were educated to middle school level or higher, 45.4% had a household income < 297 USD, and 29.7% had received education/training about pesticide use/adverse health effects in children. The score for caregivers’ knowledge of the adverse effects of pesticides on children’s health was higher in those who had received education/training (5.1 ± 2.6 vs. 3.4 ± 2.5, P < 0.001). Factors associated with unsafe behaviors during pesticide use included grandparent as the caregiver (odds ratio [OR] 0.551; 95% confidence interval [95% CI] 0.368–0.824; P = 0.004), annual income < 297 USD (OR 0.580; 95% CI 0.395–0.853; P = 0.006), and insufficient health-related education/training (OR 0.436; 95% CI 0.286–0.665; P < 0.001). Improved education and training are needed to promote the safe use of pesticides by caregivers of children in rural China.
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