خيارات البحث
النتائج 3441 - 3450 من 8,010
Tracing consumption patterns of stimulants, opioids, and ketamine in China by wastewater-based epidemiology النص الكامل
2021
Liu, Si-Yu | Yu, Wen-Jing | Wang, Yi-Ru | Shao, Xue-Ting | Wang, De-Gao
Illicit drug use has long been a key issue of international concern, and the true situation is unknown to the relevant authorities. To develop a profile of comprehensive consumption patterns of illicit drugs in China, data from 34 wastewater treatment plants in 25 cities were collected to analyze four classes of drugs, including amphetamine-type stimulants, opioids, ketamine, and cocaine. They were identified and quantified in samples using methods based on gas chromatography coupled to mass spectrometry. According to the wastewater-based epidemiology (WBE) approach, an analysis of the consumption pattern was performed regarding per inhabitant consumption based on the revised metabolic rate. The consumption quantity of illicit drug and precursor was divided into four categories based on statistical difference analyses: methamphetamine and ephedrine (precursor) were the predominant drugs in the first category, followed by ketamine and heroin in the second category, methcathinone and 3,4-methylenedioxymethamphetamine (MDMA) in the third category, and cocaine and methadone in the fourth category. There were distinctive spatial patterns: heroin and cocaine consumption was higher in Southern China than in Northern China, heroin consumption was higher in Western China than in Eastern China, and the consumption of each drug differed across seven regions of China, especially with ephedrine and methcathinone consumption higher in North China; heroin consumption higher in Southwest, Central, and Northwest China; and ketamine and MDMA consumption higher in East, South, and Central China. Compared with findings in previous studies, there were temporal patterns, in which ketamine consumption presented a downward trend but heroin remained stable. Based on correlation analyses, there were the polydrug abuse patterns between heroin and cocaine, methcathinone and ketamine, and cocaine and MDMA. In general, this study based on WBE provides a comprehensive evaluation of drug consumption in China.
اظهر المزيد [+] اقل [-]Physiological Responses of Pak Choi to Exogenous Foliar Salicylic Acid Under Soil Se Stress النص الكامل
2021
Chen, Jinping | Huang, Taiqing | Zeng, Chengcheng | Xing, Ying | Pan, Liping | Liao, Qing | Liang, Panxia | Jiang, Zepu | Liu, Yongxian
In plants, excess selenium causes general toxic symptoms. However, salicylic acid plays an important role in alleviating toxic effects of various stresses. This study aimed to clarify the role of exogenous foliar salicylic acid on alleviating selenium toxicity of pak choi exposed to moderately and highly Se-excessive soils (4 mg·kg⁻¹ Se and 10 mg·kg⁻¹ Se, respectively). The results showed that Se stress caused severe lipid peroxidation, desynchronization of the antioxidant enzymatic system, and significant decreases in the measures of photosynthetic activity and shoot biomass. Under Se stress conditions, exogenous foliar salicylic acid significantly increased measures of photosynthetic activity and shoot biomass, increased catalase activity, and decreased measures of oxidative stress. Moreover, exogenous salicylic acid significantly enhanced Se accumulation in shoots under Se stress conditions. We demonstrate here that foliar spraying with salicylic acid is an effective measure to alleviate the adverse effects of Se stress and enhance Se accumulation for optimizing crop Se biofortification in Se-excessive soil.
اظهر المزيد [+] اقل [-]Seasonal variation of heavy metals in seagrasses along Thondi coast, Palk Bay, India النص الكامل
2021
Pasumpon, Nigariga | Vasudevan, Sugumar
The present study deals with the bioaccumulation of heavy metals in different seagrass species (Syringodium isoetifolium, Halodule pinifolia, Cymodocea serrulata, Halophila ovalis) along Thondi coast and decaying seagrass offshore. Heavy metal concentrations in the seagrass samples were analysed during the period of April 2019 to March 2020 using atomic absorption spectrophotometry. Among the heavy metals assayed, the level of manganese was higher (15.62 ± 1.02 mg/kg) and chromium was the least metal observed (0.002 mg/kg). One-way ANOVA revealed significantly higher level of heavy metals in summer season, while it gradually decreased through pre-monsoon to monsoon season (P < 0.05). Cadmium and chromium were observed to be below detectable levels in the seagrass species. S. isoetifolium was found to bioaccumulate higher levels of heavy metals than the other seagrass species studied. Elucidation of heavy metal levels in the dead and decayed seagrass offshore revealed a higher level of heavy metals than live seagrass species.
اظهر المزيد [+] اقل [-]Breast cancer and DDT: putative interactions, associated gene alterations, and molecular pathways النص الكامل
2021
Jayaseelan, Vijayashree Priyadharsini | Ramesh, Anita | Arumugam, Paramasivam
The global burden of cancer has recorded an ever-increasing trend in the developing world. The GLOBOCAN, 2018 report has ranked breast cancer (BC) as the second (11.6%) most common form of cancer afflicting the female population worldwide. BC presents as a multi-factorial trait with numerous risk factors associated with the disease phenotype. Besides, genetic predisposition, exposure to environmental chemicals, and pollutants are considered to increase the magnitude of disease in susceptible individuals. Hence, the present observational study aims to investigate those proteins in the host which interact with the persistent organic pollutant, 2,4-dichlorodiphenyltrichloroethane (DDT), and associated alterations in genes encoding these proteins using a computational approach. The genetic alterations were ascertained using the Breast Invasive Carcinoma dataset available in the cBioportal database. The possible functional consequences of mutations identified in the selected dataset were further assessed using tools such as I-Mutant and PROVEAN. The ERBB2 (14%) and FASLG (10%) genes were found to harbor the highest frequency of gene alterations. Gene amplification and deep deletions were the most commonly observed alteration in almost all the genes investigated. Additionally, several synonymous, non-synonymous, frameshift, splice site mutations were also documented. The gnomAD analysis revealed three polymorphic variants in HTR2A (rs539430264), ESR2 (rs905821436), and CYP2B6 (rs757834610), all of which had a minor allele frequency < 0.01. Population-wide screening of observed gene alterations can provide clues on the putative association of these gross and single nucleotide substitutions with the pathophysiology and progression of breast cancer. Experimental genotyping and functional analysis of mutations is warranted to further prove the adverse effects of organochlorine compounds on female health.
اظهر المزيد [+] اقل [-]Salinity exacerbates oil contamination effects in mangroves النص الكامل
2021
Naidoo, Gonasageran | Naidoo, Krishnaveni
The effects of salinity (10 and 50% seawater) and oil in combination on three mangroves, Avicennia marina, Bruguiera gymnorrhiza, and Rhizophora mucronata, were investigated. In all species, plant height, number of leaves, and CO₂ exchange were generally higher in 10% than in 50% seawater. Salinity and oil decreased plant height, number of leaves, chlorophyll content, and CO₂ exchange, with reductions being greater at the higher salinity. In a second experiment, the effects of salinity (0, 10, and 50% seawater) and oil on concentrations of ions, polycyclic aromatic hydrocarbons (PAHs), leaf ultrastructure, and salt secretion in A. marina were investigated. Salinity and oil in combination increased concentrations of Na⁺ but decreased those of K⁺, Ca²⁺, and Mg²⁺. PAHs caused damage to cell membranes, disrupted ion concentrations, and reduced salt secretion. This study demonstrated that increase in salinity reduces growth of mangroves and that salinity and oiling in combination exacerbate growth reduction. In A. marina, oil was absorbed and translocated to the leaves where it disrupted membranes, ion accumulation, and salt secretion.
اظهر المزيد [+] اقل [-]Understanding consumer participation in managing ICT waste: Findings from two-staged Structural Equation Modeling–Artificial Neural Network approach النص الكامل
2021
Najmi, Arsalan | Kanapathy, Kanagi | Aziz, Azmin Azliza
For environmental management, the role of consumers is extremely important in the settings of reverse logistics. Though it is a manufacturer’s extended responsibility to handle the waste however by becoming the supplier of the end of life products, consumers’ participation needed to be encouraged and hence require proper attention. For the said purpose, the present study is conducted whereby crucial determinants of consumer reversing behavior were identified and analyzed by the help of a unique two-staged methodology of partial least square-structural equation modeling and artificial neural network. The data comprised of 746 collected by the survey from ICT users whereby the findings reported to have significant relationships of return intention and reversing behavior with their determinants. Moreover, the aforementioned unique methodology helps in generating more robust results as findings from ANN reported to have moral norm as most important variable which according to PLS-SEM was second most significant construct, whereas attitude was found to be second most important as per ANN which according to PLS-SEM is the most significant construct. Nevertheless, the study offers insights which contributes in the literature of environmental management, reverse logistics, and consumer behavior. Lastly, based on the findings, the managerial implications and recommendations are accordingly discussed.
اظهر المزيد [+] اقل [-]Classification Maps for TDS Concentrations in the GIS Along Euphrates River, Iraq النص الكامل
2021
Chabuk, Ali | Hammood, Zahraa Ali | Anṣārī, Naẓīr | Abed, Salwan Ali | Laue, Jan
Iraq currently undergoing the problem of water shortage, although Iraq has two Rivers (Euphrates and Tigris) pass throughout most of its areas, and they have represented a major source of water supply. In the current research, to evaluate the quality of the Euphrates river in Iraq based on the values of total dissolved salts (TDS), the TDS concentrations were collected from sixteen sections along the river in the three succeeding years (2011, 2012, and 2013). The evaluation of the river was done depending on the classification of (W.H.O. (World Health Organization). (2003). Total Dissolved Salts in Drinking-water: Background document for development of W.H.O. Guidelines for Drinking-water Quality. World Health Organization, 20 Avenue Appia, 1211 Geneva 27, Switzerland). of rivers for drinking uses. Inverse Distance Weighting Technique (IDWT) as a tool in the GIS was employed to establish the maps of the river that using interpolation/prediction for the TDS concentrations to each selected year and the average values of TDS for these 3 years. Based on the five categories of rivers’ classification of the TDS concentrations according to the (W.H.O. (World Health Organization). (2003). Total Dissolved Salts in Drinking-water: Background document for development of W.H.O. Guidelines for Drinking-water Quality. World Health Organization, 20 Avenue Appia, 1211 Geneva 27, Switzerland), the Euphrates river was classified, and the maps of classification for the years 2011, 2012 and 2013 and the average values for 3 years were created. The average values for 3 years of TDS along the Euphrates river indicated that the sections from SC-1 to SC-4 as moderate-water-quality-Category-3, the sections from SC-5 to SC-10 as poor-water-quality-Category-4, while the sections between SC-11 to SC-16 as very poor-water-quality-Category-5. The interpolation maps showed that the Euphrates river in Iraq was ranged from moderate water quality (Category-3) to very poor water quality (Category-5).
اظهر المزيد [+] اقل [-]The effectiveness of surfactants applied with essential oil of Lippia alba in the anesthesia of Nile tilapia (Oreochromis niloticus) and their toxicity assessment for fish and mammals النص الكامل
2021
Postay, Laís Frigini | Cabral, Dandara Silva | Heringer, Otávio Arruda | Vieira, Luiza Valli | de Moraes, Lauro Roger | Freitas, Gabrieli | Gomes, Levy Carvalho
The Lippia alba essential oil (EO) is a fish anesthetic immiscible in water and commonly used diluted in ethanol. We evaluated the effectiveness of surfactant use with Lippia alba EO in the anesthesia of Oreochromis niloticus, as well as its toxicity in fish and mammals. The EO was extracted by hydrodistillation and the fish were exposed to anesthesia at the concentration of 250 μL/L for 10 min with the surfactants polysorbate 20 (T20), polysorbate 80 (T80), polyethylene glycol (PEG), and ethanol. We also evaluated fish recovery and anesthetic safety margin after exposure for 10, 20, and 30 min. To assess the surfactants’ toxicity in mammals, Mus musculus (mice) received the same treatments by gavage. The main constituents of the Lippia alba EO were linalool (42.36%), geraniol (12.46%), neral (10.7%), and limonene (7.45%). Deeper anesthesia was faster in the T20 (60 ± 2.9 s) and T80 (272 ± 21 s) treatment groups, while recovery time for T80 was longer (596 ± 47 s). All treatments showed a good safety margin, without mortality. The genotoxic effects caused by surfactants in mammals and fish were at similar levels to those found in the ethanol treatment. Therefore, this study demonstrated that the use of surfactants T20 and T80 in Oreochromis niloticus anesthesia presented neither a reduction nor a considerable increase of the toxicity when compared to the commonly used ethanol; however, an increase in anesthetic effectiveness was observed throughout the experiment.
اظهر المزيد [+] اقل [-]Thermal modeling, characterization, and enviro-economic investigations on inclined felt sheet solar distiller for seawater desalination النص الكامل
2021
Hilarydoss, Sharon | Delhiraja, Krithika | Reddy, Kalvala Srinivas | Philip, Ligy | Chand, Drupad | Benny, Belmin
Sustainable desalination can be achieved by adopting renewable energy-based low-cost and low-impact desalting techniques. In this investigation, capability of inclined felt sheet solar distiller in desalting seawater is assessed by evaluating its performance, distillate water quality, economics, and environmental impacts. The distiller with 1.18-m² aperture area produced around 4.60 L/day of distillate for a cumulative incident solar radiation intensity of about 20.52 MJ/m² day. Its pollutant removal efficiency is very much superior to other available solar stills reported in literatures. Thermal model developed for estimating distiller’s performance is able to predict its productivity with reasonable accuracy (only 8.0% deviation from experimental values) and was used for estimating distiller’s performance in various seashore locations in India with varying clear days (191 to 246). Yearly mean distillate production and thermal and exergy efficiencies of the proposed distiller range between 3.60 to 4.50 L/day, 36.45 to 42.39%, and 2.85 to 3.65%, respectively, in east seashore locations of India. Moreover, 18.46 tons of CO₂, 132.72 kg of SO₂, and 54.20 kg of NO emission can be mitigated by adopting the distiller for potable water production. Distillate production cost of inclined felt sheet solar distiller is in the range of 1.15 to 2.29 INR/L and highly depends on the interest rate at which the distiller is financed. Generation of reasonable quantity of high-quality potable water at low cost with huge environmental benefits makes proposed inclined felt sheet solar distiller a suitable option for quenching thirst in coastal and remote locations.
اظهر المزيد [+] اقل [-]Do renewable energy and natural gas consumption mitigate CO2 emissions in the USA? New insights from NARDL approach النص الكامل
2021
Çıtak, Ferhat | Uslu, Hakan | Batmaz, Oğuzhan | Hoş, Safa
This article attempts to explore the asymmetric impact of renewable energy and natural gas consumptions on CO₂ emissions for the selected ten most populous states in the USA over the period from 1997 to 2017. For that purpose, the nonlinear autoregressive distributed lag (NARDL) estimation technique, developed by Shin et al. (2014), decomposes the consumption of renewable energy and natural gas into positive and negative changes. The cointegration test results indicate that renewable energy and natural gas consumptions have a long-run connection with CO₂ emissions in the eight of states used in the study. Moreover, the results reveal that the long-run asymmetric impact of renewable energy and natural gas consumptions on CO₂ emissions differs from state to state. Finally, the study provides several important policy suggestions, including reducing the CO₂ emissions in the atmosphere.
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