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Hollow porous molecularly imprinted polymers as emerging adsorbents
2021
Bhogal, Shikha | Kuldip Kaur, | Mohiuddin, Irshad | Kumar, Sandeep | Lee, Jechan | Brown, Richard J.C. | Kim, Ki Hyun | Malik, Ashok Kumar
Hollow porous molecularly imprinted polymers (HPMIPs) are identified as promising adsorbents with many advantageous properties (e.g., large number of imprinted cavities, highly accessible binding sites, controllable pore structure, and fast mass transfer). Because of such properties, HPMIPs can exhibit improved binding capacity and kinetics to make analyte molecules readily interact with a greater number of recognition sites on the imprinted shell. This review highlights the synthesis and utility of HPMIPs as adsorbents to cover diverse targets of interest (e.g., endocrine disrupting chemicals, pharmaceuticals, pesticides, and heavy metal ions). The overall potential of HPMIPs is thus discussed in the context of analytical chemistry with particular focus on the efficient extraction of trace-level targets from complex matrices.
显示更多 [+] 显示较少 [-]Acute and subacute oral toxicity of propylene glycol enantiomers in mice and the underlying nephrotoxic mechanism
2021
Zhou, Yixi | Zhao, Xijing | Hu, Weiping | Ruan, Fengkai | He, Chengyong | Huang, Jiyi | Zuo, Zhenghong
Propylene glycol (PG; 1,2-propanediol) has been commonly used as a food additive and vehicle in pharmaceutical preparations. PG can form rectus (R-) enantiomers and sinister (S-) enantiomers. Herein, Kunming mice were used as the animal model to evaluate the acute and subacute oral toxicity of R-PG, S-PG and RS-PG (1:1 racemic mixture of R-PG and S-PG). The median lethal doses of R-PG, S-PG and RS-PG administered by oral gavage to mice were 22.81 g/kg, 26.62 g/kg and 24.92 g/kg, respectively. In the 28-day oral subacute toxicity study, the body weight, organ weights, serum biochemical, and renal histology were examined. There was no difference in subacute toxicity among R-PG, S-PG and RS-PG. The administration of 1 and 5 g/kg/day PG for 28 days caused nephrotoxicity. The kidney somatic index and levels of blood urea nitrogen exhibited a significant increase. Moreover, the activities of superoxide dismutase, catalase, and glutathione peroxidase significantly decreased after the treatment with PG. The levels of malondialdehyde, tumor necrosis factor α, interleukin 1β, and interleukin 6 significantly increased in the kidney. The results show that the nephrotoxic effects of PG are induced by oxidative stress, and the activation of the inflammatory response is mediated by the NF-κB signaling pathway. Together, these findings provide information on R-PG, S-PG and RS-PG treatments for the risk assessment of toxicity and effects on human health.
显示更多 [+] 显示较少 [-]Plastic additives and personal care products in south China house dust and exposure in child-mother pairs
2021
Shi, Yumeng | Liu, Xiaotu | Xie, Qitong | Pan, Xiong-Fei | Mei, Zhixiong
Indoor environment constitutes an important source of industrial additive chemicals to human exposure. We hypothesized that the influence of residential environment on human exposure varies among different types of additive chemicals and differs between children and mothers. This study determined a suite of additive chemicals in house dust from South China dwellings (n = 47) and urine from child-mother pairs. Concentrations of phthalates (PAEs; median 601 μg/g) were 2–3 orders of magnitude greater than those of parabens (0.82 μg/g), bisphenols (3.31 μg/g), and benzophenone-related chemicals (2.69 μg/g). Urinary concentrations differed between children and mothers, but the pattern of differences varied between chemical groups. Children exhibited greater urinary levels of mono-PAEs than mothers (510 versus 395 ng/mL, p = 0.152), while the latter population exhibited greater levels of parabens and benzophenones. Regression analyses indicate a lack of association between dust and urinary levels for most chemicals, suggesting that other exposure pathways can complicate human exposure scenarios. Indeed, we estimated that the daily intake via dust ingestion only constituted 0.002–0.81% of total daily intake estimated based on urine data for mothers and 0.04–5.61% for children. Future efforts are needed to better characterize source-specific exposure for different populations.
显示更多 [+] 显示较少 [-]Organic-matter decomposition as a bioassessment tool of stream functioning: A comparison of eight decomposition-based indicators exposed to different environmental changes
2021
Ferreira, Verônica | Silva, João | Cornut, Julien | Sobral, Olímpia | Bachelet, Quentin | Bouquerel, Jonathan | Danger, Michael
Organic-matter decomposition has long been proposed as a tool to assess stream functional integrity, but this indicator largely depends on organic-matter selection. We assessed eight decomposition-based indicators along two well-known environmental gradients, a nutrient-enrichment gradient (0.2–1.4 mg DIN/L) in central Portugal and an acidification gradient (pH: 4.69–7.33) in north-eastern France to identify the most effective organic-matter indicator for assessing stream functional integrity. Functional indicators included natural leaf litter (alder and oak) in 10-mm and 0.5-mm mesh bags, commercial tea (Lipton green and rooibos teas in 0.25-mm mesh bags), wood sticks (wood tongue depressors) and cotton strips. Biotic indices based on benthic macroinvertebrates (IPtIN for Portugal and IBGN for France) were calculated to compare the effectiveness of structural and functional indicators in detecting stream impairment and to assess the relationship between both types of indicators. The effectiveness of organic-matter decomposition rates as a functional indicator depended on the stressor considered and the substrate used. Decomposition rates generally identified nutrient enrichment and acidification in the most acidic streams. Decomposition rates of alder and oak leaves in coarse-mesh bags, green and rooibos teas and wood sticks were positively related with pH. Only decomposition rates of rooibos tea and wood sticks were related with DIN concentration; decomposition rates along the nutrient-enrichment gradient were confounded by differences in shredder abundance and temperature among streams. Stream structural integrity was good to excellent across streams; the IPtIN index was unrelated to DIN concentration, while the IBGN index was positively related with pH. The relationships between decomposition rates and biotic indices were loose in most cases, and only decomposition rates of alder leaves in coarse-mesh bags and green tea were positively related with the IBGN. Commercial substrates may be a good alternative to leaf litter to assess stream functional integrity, especially in the case of nutrient enrichment.
显示更多 [+] 显示较少 [-]Is water quality better in wet years or dry years in river-connected lakes? A case study from Dongting Lake, China
2021
Geng, Mingming | Wang, Kelin | Yang, Nan | Qian, Zhan | Li, Feng | Zou, Yeai | Chen, Xinsheng | Deng, Zhengmiao | Xie, Yonghong
Water quality is essential for lake systems, which are not only influenced by climate change and human activities but are also controlled by high-frequency hydrological rhythms. However, the differences in water quality during different hydrological periods have not been addressed in detail. Here, a 15-year water quality dataset (2004–2018) was selected to explore the variation trends and their relationship with water level in different hydrological periods in Dongting Lake, a typical river-connected lake in China. The hydrological periods were classified into hydrological years and hydrological phases based on the characteristics of water level fluctuations. The results showed that annual variation in the water level in Dongting Lake fluctuated between 23.63 and 25.81 m from 2004 to 2018, and also displayed considerable water level differences ranging from 7.66 m (dry years) to 9.97 m (wet years) within a year. The water level of the lake phase showed significant differences among the different hydrological years. The concentration of TP, CODMₙ, and NH₃-N showed significant decreasing trends, whereas that of TN showed a significant increasing trend from 2004 to 2018. The TN concentration in wet years was significantly higher than that in dry years, which could be attributed to sewage discharge and hydrological conditions. The contributions of the lake phase to the total sewage discharge successively decreased from 64.54% in wet years to 59.47% in dry years, while the river phase showed the opposite trends, ranging from 35.46% to 40.53%, reflecting the strong relationship between water regimes and pollutant fluxes. A regression analysis indicated the different responses of water quality to water level fluctuations over hydrological years, and water quality in different hydrological phases clearly separated the lake and river phases, highlighting the influence of water level fluctuations on water quality within a year. To maintain the water quality of Dongting Lake, the control of external load should not be relaxed, and hydrological regulation should be actively carried out within each year.
显示更多 [+] 显示较少 [-]Real-time prediction of river chloride concentration using ensemble learning
2021
Zhang, Qianqian | Li, Zhong | Zhu, Lu | Zhang, Fei | Sekerinski, Emil | Han, Jing-Cheng | Zhou, Yang
Real-time river chloride prediction has received a lot of attention for its importance in chloride control and management. In this study, an artificial neural network model (i.e., multi-layer perceptron, MLP) and a statistical inference model (i.e., stepwise-cluster analysis, SCA) are developed for predicting chloride concentration in stream water. Then, an ensemble learning model based on MLP and SCA is proposed to further improve the modeling accuracy. A case study of hourly river chloride prediction in the Grand River, Canada is presented to demonstrate the model applicability. The results show that the proposed ensemble learning model, MLP-SCA, provides the best overall performance compared with its two ensemble members in terms of RMSE, MAPE, NSE, and R² with values of 11.58 mg/L, 27.55%, 0.90, and 0.90, respectively. Moreover, MLP-SCA is more competent for predicting extremely high chloride concentration. The prediction of observed concentrations above 150 mg/L has RMSE and MAPE values of 9.88 mg/L and 4.40%, respectively. The outstanding performance of the proposed MLP-SCA, particularly in extreme value prediction, indicates that it can provide reliable chloride prediction using commonly available data (i.e., conductivity, water temperature, river flow rate, and rainfall). The high-frequency prediction of chloride concentration in the Grand River can supplement the existing water quality monitoring programs, and further support the real-time control and management of chloride in the watershed. MLP-SCA is the first ensemble learning model for river chloride prediction and can be extended to other river systems for water quality prediction.
显示更多 [+] 显示较少 [-]Adsorption mechanism of two pesticides on polyethylene and polypropylene microplastics: DFT calculations and particle size effects
2021
Mo, Qiming | Yang, Xingjian | Wang, Jinjin | Xu, Huijuan | Li, Wenyan | Fan, Qi | Gao, Shuang | Yang, Wenyi | Gao, Chengzhen | Liao, Dehua | Li, Yongtao | Zhang, Yulong
Polyethylene (PE) and polypropylene (PP) microplastics (MPs), as carriers, can bind with pesticides, which propose harmful impacts to aqueous ecosystems. Meanwhile, carbofuran and carbendazim (CBD), two widely used carbamate pesticides, are toxic to humans because of the inhibition of acetylcholinesterase activity. The interaction between two MPs and two pesticides could start in farmland and be maintained during transportation to the ocean. Herein, the adsorption behavior and mechanism of carbofuran and carbendazim (CBD) by PE and PP MPs were investigated via characterization and density functional theory (DFT) simulation. The adsorption kinetic and thermodynamic data were best described by pseudo-second-order kinetics and the Freundlich models. The adsorption behaviors of individual carbofuran/CBD on both MPs were very similar. The CBD adsorption rate and capacity of PE and PP MPs were higher than those of carbofuran. This phenomenon explained the lower negative effects of DOM (oxalic acid, glycine (Gly)) on CBD adsorption relative to those of carbofuran. The presence of oxalic acid and Gly decreased the PE adsorption by 20.40–48.02% and the PP adsorption by 19.27–42.11%, respectively. It indicated the significance of DOM in carbofuran cycling. The adsorption capacities were negatively correlated with MPs size, indicating the importance of specific surficial area. Fourier transformation infrared spectroscopy before and after adsorption suggested that the adsorption process did not produce any new covalent bond. Instead, intermolecular van der Waals forces were one of the primary adsorption mechanisms of carbofuran and CBD by MPs, as evidenced by DFT calculations. Based on the zeta potential, the electrostatic interaction explained the higher adsorption CBD by MPs than carbofuran.
显示更多 [+] 显示较少 [-]Effects of high-dose bisphenol A on the mouse oral mucosa: A possible link with oral cancers
2021
Araujo Almeida, Tatiana Fernandes | Oliveira, Sicília Rezende | Mayra da Silva, Janine | Fernandes de Oliveira, Ana Laura | de Lourdes Cardeal, Zenilda | Menezes, Helvécio Costa | Gomes, José Messias | Campolina-Silva, Gabriel Henrique | Oliveira, Cleida Aparecida | Macari, Soraia | Garlet, Gustavo Pompermaier | Alves Diniz, Ivana Márcia | Leopoldino, Andréia Machado | Aparecida Silva, Tarcília
Bisphenol A (BPA) is an endocrine disrupting chemical able to promote hormone-responsive tumors. The major route of BPA contamination being oral, the aim of the present study was to investigate BPA effects on oral cells. Here, we evaluated the impact of sub-chronic in vivo exposure to BPA and its in vitro effects on neoplastic and non-neoplastic oral cells. We evaluated the oral mucosa of mice chronically exposed to BPA (200 mg/L). The response of keratinocytes (NOK–SI) and Head and Neck (HN) Squamous Cell Carcinoma (SCC), HN12 and HN13 cell lines to BPA was examined. In vivo, BPA accumulated in oral tissues and caused an increase in epithelial proliferative activity. BPA disrupted the function of keratinocytes by altering pro-survival and proliferative pathways and the secretion of cytokines and growth factors. In tumor cells, BPA induced proliferative, invasive, pro-angiogenic, and epigenetic paths. Our data highlight the harmful effects of BPA on oral mucosa and, tumorigenic and non-tumorigenic cells. Additionally, BPA may be a modifier of oral cancer cell behavior by prompting a functional shift to a more aggressive phenotype.
显示更多 [+] 显示较少 [-]Microplastics and trace metals in fish species of the Gulf of Mannar (Indian Ocean) and evaluation of human health
2021
Selvam, S. | Manisha, A. | Roy, Priyadarsi D. | Venkatramanan, S. | Chung, S.Y. | Muthukumar, P. | Jesuraja, K. | Elgorban, Abdallah M. | Ahmed, Bilal | Elzain, Hussam Eldin
The importance of microplastic (MPs) contamination in marine environments is reflected by increasing number of studies in fish species. Some even dedicated to the toxicological effects from the ingestion. Microplastics (MPs) and their trace metal composition were examined in the muscle and intestine of five commercially important fish species (i.e., Sufflamen fraenatus, Heniochus acuminatus, Atropus atropos, Pseudotriacanthus and Leiognathus brevirostris) from Thoothukudi at the Gulf of Mannar coast in south India. The abundance and morphology of MPs (size, shape, and texture) in muscle and intestinal were investigated by micro-Fourier Transform Infrared Spectroscopy (μ-FT-IR) and atomic force microscope (AFM). ICP-OES was used to investigate the adsorption/leaching of trace metals in microplastics in order to assess health risk for adults and children. Particles of 100–250 μm and white color dominated, and the mean abundances (items/100 g) of total MPs were more in Pseudotriacanthus (muscle: 51.2; intestine: 50.1) compared to Heniochus acuminatus (muscle: 9.6; intestine: 15), Leiognathus brevirostris (muscle: 12; intestine: 13.2) and Atropus atropus (muscle: 15.2; intestine: 44.1). Polyethylene (35.3%), polypropylene (27.2%), polyamide (nylon) (22.2%) and fiber (15.3%) represented the MPs present in muscles, and polyamide (nylon) (30.2%), polyethylene (28.1%), polypropylene (25.9%), and fiber (15.8%) composed the intestine MPs. We estimated possible consumption of 121–456 items of MPs/week by adults and about 19–68 items of MPs/week by children by considering the sizes of safe meals. Zn, Cu, Mn and Cr in these fish species reflected influence of the sewage waste. However, the non-carcinogenic risk evaluated through EDI, THQ, HI, and CR did not suggest any immediate health problem for the consumers.
显示更多 [+] 显示较少 [-]Macroinvertebrates as biomonitors of pollutants on natural sandy beaches: Overview and meta-analysis
2021
Costa, Leonardo Lopes | da Costa, Monica Ferreira | Zalmon, Ilana Rosental
This review synthesises information from published articles on the incorporation of pollutants by macroinvertebrates from sandy beaches, including both field samplings and bioassays. The hypothesis that macroinvertebrates quantitatively reflect the presence of pollutants in sediment, acting as biomonitors, was tested through a meta-analysis based on studies performed in situ. More than half of the studies were conducted in the Mediterranean. Of the 53 articles based on field samplings, less than half (40%) determined the concentration of pollutants in the sediment as well as in the organisms. Donacidae, Talitridae, and Hippidae were tested as biomonitors, mainly of trace elements. Donacidae and Talitridae reflected in their soft tissues the presence of most trace elements in the sediment, which was not the case with Hippidae. Few studies (≤2 articles) evaluated the response of these macroinvertebrates to persistent organic pollutants, hydrocarbons, or microplastic. A selection based on sampling of sediment and species not yet tested as biomonitors is necessary due to the scarcity of a baseline worldwide and because responses to pollutants may be species-specific.
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