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Multigenerational study of the obesogen effects of bisphenol S after a perinatal exposure in C57BL6/J mice fed a high fat diet النص الكامل
2021
Brulport, Axelle | Le Corre, Ludovic | Maquart, Guillaume | Barbet, Virginie | Dastugue, Aurélie | Severin, Isabelle | Vaiman, Daniel | Chagnon, Marie-Christine
Bisphenol S is an endocrine disruptor exhibiting metabolic disturbances, especially following perinatal exposures. To date, no data are available on the obesogen effects of BPS in a mutligenerational issue.We investigated obesogen effects of BPS in a multigenerational study by focusing on body weight, adipose tissue and plasma parameters in male and female mice.Pregnant C57BL6/J mice were exposed to BPS (1.5 μg/kg bw/day ie a human equivalent dose of 0.12 μg/kg bw/day) by drinking water from gestational day 0 to post natal day 21. All offsprings were fed with a high fat diet during 15 weeks. Body weight was monitored weekly and fat mass was measured before euthanasia. At euthanasia, blood glucose, insuline, triglyceride, cholesterol and no esterified fatty acid plasma levels were determined and gene expressions in visceral adipose tissue were assessed. F1 males and females were mated to obtain the F2 generation. Likewise, the F2 mice were cross-bred to obtain F3. The same analyses were performed.In F1 BPS induced an overweight in male mice associated to lipolysis gene expressions upregulation. In F1 females, dyslipidemia was observed. In F2, BPS exposure was associated to an increase in body weight, fat and VAT masses in males and females. Several plasma parameters were increased but with a sex related pattern (blood glucose, triglycerides and cholesterol in males and NEFA in females). We observed a down-regulation in mRNA expression of gene involved in lipogenesis and in lipolysis for females but only in the lipogenesis for males. In F3, a decrease in VAT mass and an upregulation of lipogenesis gene expression occurred only in females.BPS perinatal exposure induced sex-dependent obesogen multigenerational effects, the F2 generation being the most impacted. Transgenerational disturbances persisted only in females.
اظهر المزيد [+] اقل [-]Alkylation modified pistachio shell-based biochar to promote the adsorption of VOCs in high humidity environment النص الكامل
2022
Cheng, Tangying | Li, Jinjin | Ma, Xiuwei | Zhou, Lei | Wu, Hao | Yang, Linjun
The objective of this work was to evaluate the adsorption capacity of alkylated modified porous biochar prepared by esterification and etherification (PSAC-2) for low concentrate volatile organic compounds (VOCs, toluene and ethyl acetate) in high humidity environment by experiments and theoretical calculations. Results showed that PSAC-2 has a large specific surface area and weak surface polarity, at 80% relative humidity, its capacities for toluene and ethyl acetate adsorption could be maintained at 92% and 87% of the initial capacities (169.9 mg/g and 96.77 mg/g). The adsorption behaviors of toluene, ethyl acetate, and water vapor were studied by adsorption isotherms, and isosteric heat was obtained. The desorption activation energy was obtained by temperature programmed desorption experiment. The outcomes manifested that the PSAC-2 can achieve strong adsorption performance for weakly polar molecules. Through density functional theory (DFT) simulations, owing to the interaction of hydrogen bonds, oxygen-containing groups became a significant factor influencing the adsorption of VOCs in humid environments. These results could provide an important reference for VOCs control in a high humidity environment.
اظهر المزيد [+] اقل [-]Quantification and speciation of volatile fatty acids in the aqueous phase النص الكامل
2017
Lee, Jechan | Kim, Jieun | Oh, Jeong-Ik | Lee, Sang Ryong | Kwon, Eilhann E.
This study lays great emphasis on establishing a reliable analytical platform to quantify and specify volatile fatty acids (VFAs) in the aqueous phase by derivatizing VFAs into their corresponding alkyl esters via thermally-induced rapid esterification (only 10 s reaction time). To this end, reaction conditions for the thermally-induced rapid esterification are optimized. A volumetric ratio of 0.5 at 400 °C for VFA/methanol is identified as the optimal reaction conditions to give ∼90% volatile fatty acid methyl ester (VFAME) yield. To maintain a high yield of VFAMEs, this study suggests that dilution of the sample to an optimum concentration (∼500 ppm for each VFA) is required. Derivatization of VFAs into VFAMEs via the thermally-induced rapid esterification is more reliable to quantify and specify VFAs in the aqueous phase than conventional colorimetric method.
اظهر المزيد [+] اقل [-]Influence of Cd toxicity on subcellular distribution, chemical forms, and physiological responses of cell wall components towards short-term Cd stress in Solanum nigrum النص الكامل
2021
Wang, Juncai | Chen, Xunfeng | Chu, Shaohua | Hayat, Kashif | Chi, Yaowei | Zhi, Yuee | Zhang, Dan | Zhou, Pei
Solanum nigrum is a well-documented cadmium (Cd) hyperaccumulator; however, its Cd-induced tolerance capability and detoxification mechanism remain elusive. Hence, a short-term hydroponic experiment was performed in a multiplane glasshouse to determine the influence of Cd toxicity on subcellular distribution, chemical forms, and the physiological responses of cell wall towards Cd stress in a 4-week-old plant. The experiment was conducted following completely randomized design (CRD) with five treatments (n = 4 replicates). The results showed that Cd stress showed dose-dependent response towards growth inhibition. The subcellular distribution of Cd in S. nigrum was in the order of cell wall > soluble fractions > organelles, and Cd was predominantly extracted by 1 M NaCl (29.87~43.66%). The Cd contents in different plant tissues and cell wall components including pectin, hemicellulose 1 (HC1), hemicellulose 2 (HC2), and cellulose were increased with the increase in Cd concentrations; however, the percentage of Cd concentration decreased in pectin and cellulose. Results of the polysaccharide components such as uronic acid, total sugar contents, and pectin methylesterase (PME) activity showed Cd-induced dose-dependent increase relative to exposure Cd stress. The pectin methylesterase (PME) activity was significantly (p < 0.05) enhanced by 125.78% at 75 μM Cd in root, 105.78% and 73.63% at 100 μM Cd in stem and leaf, respectively. In addition, the esterification, amidation, and pectinase treatment of cell wall and Fourier transform infrared spectroscopy (FTIR) assay exhibited many functional groups that were involved in cell wall retention Cd, especially on carboxyl and hydroxyl groups of cell wall components that indicated that the –OH and –COOH groups of S. nigrum cell wall play a crucial role in Cd fixation. In summary, results of the current study will add a novel insight to understand mobilization/immobilization as well as detoxification mechanism of cadmium in S. nigrum.
اظهر المزيد [+] اقل [-]Comparison of adsorption behaviors and mechanisms of methylene blue, Cd2+, and phenanthrene by modified biochars derived from pomelo peel النص الكامل
2021
Li, Baoqing | Zheng, Zhiran | Fang, Jianzhang | Gong, Jiaxin | Fang, Zhanqiang | Wang, Wenxiang
Although biochar (BC) has been widely used to adsorb pollutants in environment due to its natural and green characteristics, the structural defects of BC limit the ability to remove various environmental pollutants in aqueous solution. In this study, oxidized biochar (OBC) and sulfhydryl biochar (SBC) derived from pomelo peel (PP) were prepared through an oxidation and esterification reaction. BC and modified BC were used for the removal of methylene blue (MB), Cd²⁺, and phenanthrene (PHE) in aqueous solution. The adsorption behavior and efficiency toward different types of pollutants were studied by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), Raman, X-ray photoelectron spectroscopy (XPS), kinetics, and isotherm model fitting. The results showed that the change of pH had great effect on MB and Cd²⁺ adsorption, but not on PHE. SBC not only possessed the newly formed sp²-hybridized domains with easy access to aromatic pollutants but also had multiple functional groups (-COOH, -OH, -SH, -NH₂) that provided adsorption sites for positively charged pollutants. SBC was more flexible and efficient in purifying pollutants compared to BC and OBC, with the saturated adsorption capacities of MB (209.16 mg/g), Cd²⁺ (786.19 mg/g), and PHE (521.58 mg/g). Moreover, the adsorption kinetic and isotherms fitting showed that the adsorption mechanisms were closely related to the structure of biochar and the properties of pollutants, including π-π interaction, surface charge, electrostatic interaction, surface functional groups, and Van der Waals force. In addition, the analysis of structure-function relationship demonstrated the enhanced hydrophilicity and the easy exposure of the binding sites on OBC and SBC. Hence, it was significantly effective to regulate microstructure and interfacial properties to promote its adsorption behaviors of biochar.
اظهر المزيد [+] اقل [-]Optimization of process variables on two-step microwave-assisted transesterification of waste cooking oil النص الكامل
2020
Supraja, Kolli Venkata | Behera, Bunushree | Paramasivan, Balasubramanian
Scale-up and commercialization of biodiesel is often delimited by costly feedstock that adds up to the process costs. These underlying issues demand the exploration of unconventional cheap feed to improve the process economics. Conversion of waste cooking oil (WCO) into biodiesel could reduce the process costs by 60–70%. However, the continuous exposure to heat during frying leads to oxidation as well increase in the free fatty acid (FFA) content which intensifies the time and energy required for transesterification. The present study analyzes the effect of parameters over the conversion of WCO (with 8.17% FFA) into biodiesel via two-step acid-alkali-based microwave-assisted transesterification. Response surface methodology (RSM) was used to optimize the oil:methanol volume ratio, microwave power, and reaction time during the acid-catalyzed esterification to bring down the FFA below 1%. Microwave irradiation of 250 W, with methanol:oil molar ratio of 19.57:1 [oil:methanol volume ratio of 1.31 (expressed as decimal)] and reaction time of 35 s, resulted in 0.082% of FFA. Alkali-catalyzed transesterification with methanol:oil molar ratio of 5:1 with 2% sodium hydroxide at 65 °C thereby produced fatty acid methyl esters (FAMEs) with the volumetric biodiesel yield of 94.6% in 30 min. Physiochemical properties of the transesterified WCO were well comparable with the biodiesel standards. The study highlights the essentiality of multivariate optimization for the esterification process that could aid in understanding the interactive effects of variables over FFA content. Such studies would benefit in scaling up of the transesterification process at industrial level by improving the economics of the overall bioprocess.
اظهر المزيد [+] اقل [-]CuO Nanoparticle Exposure Impairs the Root Tip Cell Walls of Arabidopsis thaliana Seedlings النص الكامل
2020
Nie, Guangli | Zhao, Jian | He, Rong | Tang, Yulin
The increasing number of applications of nanoparticles (NPs) in various fields has led to negative effects on the environment. In this study, the effects of CuO nanoparticles (CuO NPs) on Arabidopsis root tips were investigated. Significant growth inhibition on Arabidopsis roots was observed after treatment with both CuO NPs (10 mg/L) and the correspondingly released Cu²⁺ (0.80 mg/L). Scanning electron microscope images demonstrated that NPs primarily deposited on the surface of root tips and penetrated intercellular spaces after CuO NP exposure. Light and fluorescence microscope visualization revealed that the root tips were damaged severely after CuO NP exposure, with swelling of the hair zone, splitting of the cell wall junction, and disordered cell arrangement in the root tip. Semiquantitative analysis by Fourier transform infrared spectroscopy demonstrated that the cell wall xyloglucan and esterified pectin contents in the roots were decreased. Similar but weaker effects on the roots were detected after Cu²⁺ treatment. Additionally, some genes related to cell wall organization were downregulated by CuO NP stress, partially contributing to the cell wall component change. The results demonstrated that CuO NPs produced phytotoxicity to the cell wall through both physical damage and biochemical disruption, causing loosening of the tethers between cellulose microfibrils in the cell wall and the disruption of cell adhesion. The phytotoxicity of CuO NPs in the plant cell wall was mainly caused by NPs and was partially related to the released Cu²⁺. These findings are helpful to understand better the negative effects of CuO NPs on plant regarding the cell wall.
اظهر المزيد [+] اقل [-]Zinc Removal from the Aqueous Solutions by the Chemically Modified Biosorbents النص الكامل
2018
Rajczykowski, Krzysztof | Sałasińska, Oktawia | Loska, Krzysztof
Biosorbents are the natural origin adsorbents, which popularity in environmental engineering is steadily increasing due to their low price, ease of acquisition, and lack of the toxic properties. Presented research aimed to analyze the possibility of chemical modification of the straw, which is a characteristic waste in the Polish agriculture, to improve its biosorption properties with respect to removal of selected metals from aquatic solutions. Biosorbents used during the tests was a barley straw that was shredded to a size in the range of 0.2–1.0 mm. The biosorption process was performed for aqueous solutions of zinc at a pH 5. Two different modifications of straw were analyzed: esterification with methanol and modification using the citric acid at elevated temperature. The results, obtained during the research, show a clear improvement in sorption capacity of the straw modified by the citric acid. In the case of straw modified with methanol, it has been shown that the effectiveness of zinc biosorption process was even a twice lower with respect to the unmodified straw. Moreover, it was concluded that the removal of analyzed metals was based mainly on the ion-exchange adsorption mechanism by releasing a calcium and magnesium ions from the straw surface to the solution. Graphical Abstract ᅟ
اظهر المزيد [+] اقل [-]Pork Lard Derived Biodiesel Production: Characterization, Engine Performance and Emission Analysis النص الكامل
2022
Rohan Jeffry Robert and C. R. Girish
The present work introduces a new methodology in the production of biodiesel from pork-lard waste having high cholesterol content and discusses its improved performance and emissions in a diesel engine. The traditional method of transesterification does not work with cholesterol due to the absence of triglycerides, therefore, the new improved method oxidizes cholesterol to fatty acids and then converts it to biodiesel ester. The procedure includes an acid reagent to break cholesterol and a renewable basic catalyst from seashells, for catalyzing the production. The acid-base system maintains the overall pH while yielding 95.6% conversion at the optimized conditions. The morphology of the produced catalyst was analyzed through FESEM and confirmed through XRD and EDX analyses. The physicochemical and ASTM properties were determined and the calorific value of the 20% biodiesel blend was found to be comparable with that of diesel. From the engine performance analysis, the thermal efficiency of the engine was observed to be higher and the exhaust emissions showed a maximum of 75% reduction in CO and 42.2% reduction in CO2 emissions, proving it to be an environment-friendly fuel. Additionally, a 32.7% reduction in smoke opacity was also observed, thus decreasing the concentration of particulate matter in the atmosphere.
اظهر المزيد [+] اقل [-]Hydroxypropyl methylcellulose-sugarcane bagasse adsorbents for removal of 17α-ethinylestradiol from aqueous solution and freshwater النص الكامل
2022
Novaes, Stephanie Dias | Oliveira, Pedro Vitoriano | Petri, Denise Freitas Siqueira
Adsorbents made of hydroxypropyl methylcellulose (HPMC) and sugarcane bagasse (BG) microparticles were applied for the separation of 17α-ethinylestradiol (EE2) from aqueous solution in batch, and from aqueous solution and freshwater in fixed-bed columns. HPMC chains and BG microparticles were crosslinked by the esterification with citric acid. The adsorbents presented compression modulus values that increased from 208 ± 20 kPa (pure HPMC) to 917 ± 90 kPa, when the content of BG particles added to HPMC was 50 wt% (HPMC50BG). The porosity (~ 97%), specific surface area (1.16 ± 0.10 m²/g) and swelling degree (20 ± 1 g water/g) values were not affected by the addition of BG particles. The adsorption isotherms determined for EE2 on HPMC and on HPMC50BG fitted to the Langmuir and Freundlich models; the adsorption capacity of HPMC was slightly higher than that of composite HPMC50BG. Nevertheless, the addition of BG particles rendered outstanding mechanical reinforcement and dimensional stability to the adsorbents. The adsorption was driven by (i) hydrophobic interactions between EE2 methylene and aromatic groups and HPMC methyl groups, as evidenced by FTIR spectroscopy, and (ii) H bonds between HPMC and EE2 hydroxyl groups, as revealed by the adsorption enthalpy change (ΔHₐdₛ) of − 45 kJ/mol. Column adsorption experiments of EE2 from aqueous solution on HPMC and HPMC50BG indicated adsorptive capacity (q₀) values of 8.06 mg/g and 4.07 mg/g, respectively. These values decreased considerably for the adsorption of EE2 from river water, probably due to the competition of EE2 with humic substances dissolved in natural water. The HPMC adsorbents could be recycled retaining up to 83% of the original efficiency.
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