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1.
Food Chem ; 317: 126459, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32113141

RESUMO

The widespread exposure of bisphenol A (BPA) presents a significant risk to human health. A rapid, ultra-sensitive and label-free colorimetric aptasensor using high affinity truncated aptamers was developed for BPA detection. Truncated 38-mer and 12-mer aptamers specific for BPA were obtained through rationally truncation from 63-mer BPA aptamer. The dissociation constants (Kd) of 38-mer and 12-mer aptamers were determined to be 13.17 nM and 27.05 nM. Then, truncated aptamers were used in label-free colorimetric detection assays based on gold nanoparticles (AuNPs). The limit of detections of aptasensors using 38-mer and 12-mer aptamers were 7.60 pM and 14.41 pM, which were 265-fold and 140-fold lower than that of the aptasensor using 63-mer aptamer, respectively. The recovery rates in milk, orange juice and mineralized water samples were 93.88% to 107.30%. Therefore, the developed BPA colorimetric aptasensor using truncated aptamers has great application prospects in food safety control and environmental monitoring.


Assuntos
Aptâmeros de Nucleotídeos/química , Compostos Benzidrílicos/análise , Colorimetria/métodos , Análise de Alimentos/métodos , Fenóis/análise , Animais , Aptâmeros de Nucleotídeos/metabolismo , Compostos Benzidrílicos/química , Compostos Benzidrílicos/metabolismo , Análise de Alimentos/instrumentação , Contaminação de Alimentos/análise , Sucos de Frutas e Vegetais/análise , Ouro/química , Limite de Detecção , Nanopartículas Metálicas/química , Leite/química , Simulação de Acoplamento Molecular , Fenóis/química , Fenóis/metabolismo , Sensibilidade e Especificidade
2.
Chemosphere ; 248: 126053, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32041067

RESUMO

Nitrogen-containing carbon materials (NCC-x) are promising metal-free catalysts for activation of peroxymonosulfate (PMS) to treat with aqueous organic pollutants. In this study, NCC-x were synthesized via a facile thermal polymerization method using urea and terephthalaldehyde as precursors. This method was derived from the polymerization method of graphitic carbon nitride (g-C3N4) and the reaction between the precursors was based on Schiff base chemistry. Compared with the synthesis of g-C3N4 using urea as the precursor, formation of a melamine ring was inhibited and the cyano groups were produced in NCC-x during the polymerization process. The obtained NCC-x catalysts had high specific surface areas, many graphite-nitrogen active sites, and high degrees of graphitization, thus exhibiting excellent activities for the degradation of bisphenol A via PMS activation. This study introduces a convenient method to obtain a highly efficient nitrogen-containing carbon PMS activator and the results are useful for the development of bisphenol A treatment by PMS activation using carbon-containing materials.


Assuntos
Compostos Benzidrílicos/química , Nitrogênio/química , Peróxidos/química , Fenóis/química , Carbono/química , Catálise , Poluentes Ambientais , Grafite , Metais , Compostos de Nitrogênio , Polimerização , Água
3.
Environ Pollut ; 259: 113907, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32023790

RESUMO

B cells contribute to produce inflammatory cytokines and antibodies, to present autoantigens, and to interact with T cells, which lead to body defense and disease control. Nuclear factor (erythroid-derived 2)-like 2(Nrf2) is responsible for gene expression of antioxidant enzymes to protect cells from oxidative stress by reactive oxygen species(ROS) production. Bisphenol A(BPA) may not be safe due to the effect on body's physiological functions. The chemicals that substitute for BPA may still have similar effects in the body. Tritan™ copolyester is a novel plastic form using BPA substitutes, 1,4-cyclohexanedimethanol(CHDM), dimethyl terephthalate(DMT), and 2,2,4,4-tetramethyl-1,3-cyclobutanediol(TMCD). Isosorbide(ISO) was also used as a substitute for TMCD and DMT. Here, we investigated whether B cell viability is influenced by BPA and its substitutes via Nrf2 induction using WiL2-NS human B lymphoblast cells. When cytotoxicity was measured by using assays with MTT, CellTiter-Glo, trypan blue and propidium iodide, cytotoxicity by BPA was higher than that by substitutes. BPA and its substitutes showed significant cytotoxicity and ROS production, which were attenuated by the treatment with N-acetylcysteine(NAC), a ROS scavenger. In addition, BPA treatment enhanced gene expression of antioxidant enzymes, heme oxygenase(HO)-1, catalase, superoxide dismutase(SOD) 1 and 2. As H2O2 treatment induced cell death and Nrf2 amount in WiL2-NS cells, BPA treatment increased Nrf2. Cell death by H2O2 was increased in doxycycline-inducible Nrf2-knockdown(KD) cells. In Cytotoxicity by the treatment with BPA or its substitutes was also enhanced in Nrf2-KD cells but that was reduced by Nrf2 overexpression compared to control cells. Taken together, these results implicate that B cell cytotoxicity by substitutes should be lower than BPA and Nrf2 can prevent B cells from BPA- or BPA substitutes-induced cytotoxicity via ROS production. Data suggest that the comprehensive studies or evaluation could be necessary to replace BPA in manufacture by other substitutes.


Assuntos
Linfócitos B , Compostos Benzidrílicos , Regulação da Expressão Gênica , Peróxido de Hidrogênio , Fator 2 Relacionado a NF-E2 , Fenóis , Linfócitos B/citologia , Linfócitos B/efeitos dos fármacos , Compostos Benzidrílicos/química , Compostos Benzidrílicos/toxicidade , Sobrevivência Celular/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Fator 2 Relacionado a NF-E2/genética , Estresse Oxidativo/efeitos dos fármacos , Oxirredutases/genética , Fenóis/química , Fenóis/toxicidade , Espécies Reativas de Oxigênio
4.
Chemosphere ; 246: 125782, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31927373

RESUMO

In our work, a series of in-situ g-C3N4-Zn/Bi2WO6 heterojunctions were synthesized by a two-step solvothermal method followed with calcination process, using dicyanamide as the precursor for g-C3N4. C3N4-Zn/BWO heterojunctions were of gossypine shape, and both C3N4 and Zn were finely distributed into BWO nanosheets, forming a hierarchical structure. C3N4-Zn/BWO with 2.0 g of precursor addition and calcined at 520 °C exhibited effectively enhanced photodegradation for typical organic contaminant BPA, degrading 93% within 120 min, and implied a maximum rate constant k of 0.0211 min-1, indicating synergistic effect of C3N4 and Zn components in C3N4-Zn/BWO heterojunction. The enhancement of photocatalysis was due to quick carriers' separations via Z-scheme system and enlarged specific surface area of as-synthesized C3N4-Zn/BWO heterojunction. Main reactive oxidation species were detected to be h+ and O2-, and nine intermediates were confirmed via anlysis of LC-MS/MS. This study provided an alternative strategy to design novel photocatalysts containing multicomponents for higher photocatalytic activity.


Assuntos
Compostos Benzidrílicos/química , Poluentes Ambientais/química , Modelos Químicos , Fenóis/química , Catálise , Cromatografia Líquida , Luz , Oxirredução , Fotólise , Espectrometria de Massas em Tandem , Zinco
5.
Chemosphere ; 247: 125780, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31945719

RESUMO

In this study, Cu0·5Mn0·5Fe2O4 nanoparticles were synthesized through a facile coprecipitation process, evaluated as highly efficient photo-Fenton catalyst for removal of bisphenol A (BPA). Benefit for its larger surface area and unique chemical composition, the Cu0·5Mn0·5Fe2O4 catalyst exhibited superior catalytic activity toward the degradation of BPA, with a rate constant values ranging from 0.247 to 1.090 min-1 based on different operating parameters (catalyst load, initial solution pH, H2O2 concentration and reaction temperature). Importantly, an excellent BPA removal efficiency exceeding 95.2% were obtained after eight successive runs of photo-Fenton process. Electron paramagnetic resonance (EPR) spectroscopy and radical scavenger experiments demonstrated that the hydroxyl radical was the dominant radical in degradation of BPA. A possible BPA degradation pathway was proposed according to the detected intermediates by GC-MS and HPLC. In brief, this work is expected to provide a new heterogeneous photo-Fenton catalyst for the organic pollutants removal from wastewater.


Assuntos
Compostos Benzidrílicos/isolamento & purificação , Peróxido de Hidrogênio/química , Nanopartículas Metálicas/química , Fenóis/isolamento & purificação , Águas Residuárias/química , Purificação da Água/métodos , Compostos Benzidrílicos/química , Catálise , Cobre , Compostos Férricos , Concentração de Íons de Hidrogênio , Radical Hidroxila , Compostos de Manganês , Compostos Orgânicos/isolamento & purificação , Óxidos , Fenóis/química
7.
Ecotoxicol Environ Saf ; 191: 110183, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31954220

RESUMO

Toxicokinetics and bioconcentration of eight common bisphenol analogues, including bisphenol A (BPA), -B, -C, -E, -S, -Z, -AF, and -AP in common carp (Cyprinus carpio) were investigated. Both free (BPfree) and total forms (BPtotal) of the bisphenols were measured in various fish tissues. The conjugated forms of bisphenols were calculated based on BPfree and BPtotal. The calculated bioconcentration factors (BCFs) based on the total bisphenols (BPtotal) in the carp whole body were in the range of 0.3-320, agreeing with previous field results from Taihu Lake, China. The elimination rate constant (ke) positively correlated with the fraction of conjugated form (fconjugated), which displayed negative correlation with their log Kow (r = -0.861, p < 0.05), indicating that conjugation facilitated their elimination and those with higher hydrophobicity were more difficult to be eliminated. Except BPA, the concentrations of all bisphenols in the carp tissues were in the order of kidney > liver â‰« muscle. The uptake rate constants (ku) in kidney (r = 0.836, p < 0.05) and in liver (r = 0.863, p < 0.05) displayed significantly positive correlations with BCFs, and ku in kidney was greater than in liver except BPA. These results indicated that kidney and liver played important roles in accumulating bisphenols in carp, and kidney made more contribution than liver for most bisphenols. Biliary excretion predominated for elimination of most bisphenols while BPA and BPS were mainly through urinary excretion.


Assuntos
Compostos Benzidrílicos/química , Compostos Benzidrílicos/farmacocinética , Carpas/metabolismo , Fenóis/química , Fenóis/farmacocinética , Alimentos Marinhos/análise , Animais , Bioacumulação , China , Lagos/química , Especificidade de Órgãos , Distribuição Tecidual , Toxicocinética
8.
J Chromatogr A ; 1609: 460437, 2020 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-31409488

RESUMO

Thermal papers (e.g. point of sale receipts, adhesive labels, tickets) significantly contribute to contamination of paper material cycles and the environment with substances of (eco-) toxicological concern. In particular, they contain color developers like endocrine disrupting bisphenols in typical concentrations of about 1-2 percent per weight (wt%). Bisphenol A (BPA) was used as the common color developer over the last decades, but it will be restricted for thermal paper application in the European Union to a limit of 0.02 wt% from 2020 onwards. Consequently, a variety of BPA substituents such as bisphenol S (BPS) and its derivatives gain importance in thermal paper application. In this study, a rapid, reliable and cost-effective method for identification and quantification of BPA, alternative color developers and related substances like sensitizers is presented based on HPLC separation coupled with diode array detection (DAD) and Corona charged aerosol detection (CAD). Quantification was performed with regard to the intended use of the substances in thermal papers. Besides traditional UV external calibration using reference standards, alternative quantification approaches, in particular UV chromophore concentration for BPS derivatives and CAD universal response technique for low-volatile color developers, were applied and compared in order to allow quantification without reference substances. A market analysis for intended used color developers and sensitizers was performed on thermal paper samples (n = 211) collected in Germany during 2018 and 2019. Pergafast 201 (in 41.7% of the samples) was the most common color developer with concentrations above 0.02 wt%, followed by BPA (36.0%), BPS (13.3%) and other BPS derivatives known as D8, D-90, BPS-MAE and TGSA, that are mainly present in adhesive labels. Sensitizers were determined in over 90% of the samples.


Assuntos
Aerossóis/análise , Compostos Benzidrílicos/análise , Marketing , Papel , Fenóis/análise , Temperatura , Compostos Benzidrílicos/química , Calibragem , Cromatografia Líquida de Alta Pressão , Cromatografia de Fase Reversa , Cor , Disruptores Endócrinos/análise , União Europeia , Alemanha , Limite de Detecção , Modelos Lineares , Fenóis/química , Padrões de Referência , Sulfonas
9.
Food Chem Toxicol ; 135: 111015, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31812737

RESUMO

Bisphenol A (BPA) and its derivatives, including bisphenols S (BPS), F (BPF), E (BPE), B (BPB), Z (BPZ), and AF (BPAF), are widely used in consumer products. Moreover, they are typically detected in the environment, food, and humans. Previous studies have linked BPA to several health risks, but it is still unclear whether BPA replacements are safe. In this study, we developed an in vitro model based on human embryonic stem cells (hESCs) to explore the potential neural toxicity of these compounds. We observed that the bisphenols affected the viability of hESCs and hESC-derived neural stem cells (NSCs) at high concentrations, with BPS being the least cytotoxic and BPAF the strongest cytotoxic compound. At human-relevant concentrations, the bisphenols did not significantly interfere with gene expression and protein levels during hESC differentiation into the neural epithelium, as well as during specification of neuron-like cells from NSCs. Nevertheless, monitoring of cell morphology changes indicated that exposure to BPA and its derivatives impaired neurite length in neuron-like cells. Thus, our findings provide insights into the molecular mechanisms of bisphenol-dependent neurotoxicity at low nanomolar levels and support the view that BPA substitutes may not be sufficiently safe for widespread use as industrial chemicals.


Assuntos
Compostos Benzidrílicos/toxicidade , Disruptores Endócrinos/toxicidade , Neuritos , Neurônios/efeitos dos fármacos , Fenóis/toxicidade , Compostos Benzidrílicos/química , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/efeitos dos fármacos , Disruptores Endócrinos/química , Humanos , Fenóis/química
10.
Food Chem Toxicol ; 135: 110889, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31629790

RESUMO

Tetramethyl bisphenol F (TMBPF) has been shown to impart unique physical properties critical for high performance of epoxy can coatings without the estrogenic activity concerns associated with other bisphenols. To further characterize the toxicological profile of TMBPF, additional endocrine-related endpoints including in vitro aromatase inhibition and steroidogenesis assays, and in vivo androgen agonism/antagonism were performed. Systemic toxicity was also assessed by a repeat dose 90-day dietary toxicity study followed by 28-day recovery period. TMBPF did not inhibit aromatase activity, and induced estradiol and testosterone at highest non-cytotoxic concentrations (10 µM) in the steroidogenesis assay. In the Hershberger assay, TMBPF showed no androgenic activity at any dose and equivocal anti-androgenic activity at the highest dose (1000 mg/kg-bw/d). In a 90-day dietary toxicity study with 28-day recovery period, observations including changes in clinical pathology, absolute and relative organ weights, and microscopic findings are discussed. In this current study, the no observed adverse effect level was considered to be 750 mg/kg-bw/d for female rats and 1000 mg/kg-bw/d for male rats with no biologically significant changes to endocrine endpoints at any dose level. Our findings provide further evidence that TMBPF is a low-toxicity substance with a toxicology profile distinct from some other bisphenols.


Assuntos
Compostos Benzidrílicos/química , Compostos Benzidrílicos/toxicidade , Embalagem de Alimentos , Metais/química , Fenóis/química , Fenóis/toxicidade , Animais , Compostos Benzidrílicos/administração & dosagem , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Feminino , Hormônios Esteroides Gonadais/antagonistas & inibidores , Humanos , Masculino , Nível de Efeito Adverso não Observado , Fenóis/administração & dosagem , Ratos , Ratos Sprague-Dawley
11.
Chemosphere ; 241: 125034, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31683430

RESUMO

In this study, Cu(0) was synthesized with NaBH4 as a reducing agent for Cu(II) and used to activate dissolved molecular oxygen (O2) under acidic conditions. The Cu(0) synthesized had much higher activity than the purchased. The roles of Cu was clarified and the formation of reactive oxygen species was discussed through direct detection for the first time. By detecting the valence change of Cu in a CuO system, Bisphenol A (BPA) was found to accelerate the transformation of Cu(II) to Cu(I). Besides, the evidence from electron spin resonance (ESR) studies and scavenging tests revealed the new roles of Cu(0) that Cu(0) could not only convert O2 to produce ·O2-, but also catalyze H2O2 to ·OH. The results from this study offer evidence of new reaction pathways in Cu-activated O2 systems and deepen understanding of the reaction between Cu species and O2.


Assuntos
Compostos Benzidrílicos/química , Cobre/química , Oxigênio/química , Fenóis/química , Espécies Reativas de Oxigênio/química , Espectroscopia de Ressonância de Spin Eletrônica , Peróxido de Hidrogênio , Oxirredução , Espécies Reativas de Oxigênio/metabolismo
12.
Environ Sci Pollut Res Int ; 27(7): 7267-7279, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31879884

RESUMO

Toxicity data on bisphenol A (BPA) effects on aquatic macrophytes remain scarce. Therefore, environmentally relevant BPA concentrations (0.03, 0.1, 0.3, 0.5, 1, and 3 µg L-1) were tested on the seagrass Cymodocea nodosa different parts length increase. All plant parts, at low BPA concentrations (0.03-0.3 µg L-1), elongated equally to the control, while their lengthening and elongation rates gradually decreased by increasing BPA concentrations. A gradual increase of "Toxicity index" with increasing BPA concentrations was observed but was lower for juvenile blades and higher for plagiotropic rhizomes and adult leaves. In all parts, the LOECs were 0.3 and the NOECs 0.1 µg L-1 at 10th day. Juvenile blades displayed, under acute stress, lengthening inhibition at lower concentrations than the rhizomes and adult blades, but at a lower extent. The EC50 values were lower for the rhizome internodes, followed by the adult blades and higher for the juvenile blades. Using as a biological "endpoint" the elongation, all C. nodosa parts and specifically the rhizomes and adult blades, followed by intermediate blades, adult sheaths, and juvenile blades, seemed to be sensitive BPA toxicity assessors. The evaluation of the relative sensitivity of the different parts to BPA toxicity could help identify the most suitable seagrass part for early diagnosis of the risk posed by BPA to seagrass meadows and could constitute a valuable tool to derive the seawater quality criteria and to be used in BPA monitoring programs for rational management of the coastal environment.


Assuntos
Alismatales , Compostos Benzidrílicos/análise , Fenóis/análise , Água do Mar/análise , Animais , Compostos Benzidrílicos/química , Fenóis/química , Água do Mar/química
13.
Environ Sci Pollut Res Int ; 27(7): 7299-7308, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31884539

RESUMO

A theoretical and experimental study of bisphenol A (BPA) degradation by the UV/H2O2 process in water is presented. The effects of the H2O2 concentration and the specific rate of photon emission (EP,0) on BPA degradation were investigated. A kinetic model derived from a reaction sequence was employed to predict BPA and hydrogen peroxide concentrations over time using an annular photochemical reactor in batch recirculation mode. The local volumetric rate of photon absorption (LVRPA) inside the photoreactor was computed using a Line Source with Parallel Plane emission model (LSPP). From the proposed kinetic model and the experimental data, the second order rate constants of the reactions between hydroxyl radicals and the main reacting species (H2O2 and BPA) were estimated applying a nonlinear regression method. A good agreement between the kinetic model and experimental data, for a wide range of operating conditions, was obtained. For BPA, H2O2, and TOC concentrations, the calculated root means square errors (RMSE) were 2.3 × 10- 2, 9.8 × 10- 1, and 9.0 × 10- 2 mmol L- 1, respectively. The simplified kinetic model presented in this work can be directly applied to scaling-up and reactor design, since the estimated kinetic constants are independent of the reactor size, shape, and configuration. Further experiments were made by employing low BPA initial concentration (100 µg L- 1) in water and real wastewater. A lower degradation rate of BPA was observed in the real wastewater, although the UV/H2O2 process has also been able to completely degrade the target pollutant in less than 1 h.


Assuntos
Compostos Benzidrílicos/química , Peróxido de Hidrogênio , Fenóis/química , Poluentes Químicos da Água , Cinética , Raios Ultravioleta
14.
Ultrason Sonochem ; 60: 104749, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31494466

RESUMO

The effectiveness and synergistic mechanisms of combining ultrasonic process (US) with peroxymonosulfate (PMS) were investigated using Bisphenol A (BPA) and Dimethyl Phthalate (DMP) as the model pollutants. Synergy between US and PMS improved the degradation of target pollutants, and PMS was found to play a dual role. The optimum dosage of PMS and the extent of efficiency promotion were found to depend on not only the ultrasonic frequency but also on the hydrophobicity of target pollutants. The scavenger quenching experiments and electron paramagnetic resonance analysis indicated that OH was responsible for DMP degradation in both US and US/PMS processes. The chemical probe experiments also proved that activation of PMS could increase the production of OH while excess PMS consumed the available radicals. Furthermore, it was found for the first time that the constituent salts of KHSO4 and K2SO4 in the commercial Oxone also made considerable influence on US/PMS process. It was also found that the combination of US and PMS showed more pronounced synergistic effect for treating DMP at lower concentrations. Higher efficiency was achieved at more acidic condition and similar efficiencies were obtained at pH range of 5.1 ~ 8.12. DMP degradation pathways were found to be the OH addition to the aromatic ring and hydrogen absorption at the aliphatic chains with and without the presence of PMS, but much better mineralization capability was obtained in the presence of PMS than ultrasonic degradation alone.


Assuntos
Disruptores Endócrinos/química , Peróxidos/química , Ondas Ultrassônicas , Compostos Benzidrílicos/química , Espectroscopia de Ressonância de Spin Eletrônica , Sondas Moleculares , Oxirredução , Fenóis/química , Ácidos Ftálicos/química , Poluentes Químicos da Água/química
15.
Environ Pollut ; 255(Pt 2): 113292, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31597112

RESUMO

The wide application of bisphenol A (BPA) leads to the emergence of BPA residuals in natural water environments. Dissolved organic matter (DOM) existed in water can bind with BPA, hence influencing the migration and transformation of BPA in aquatic environments. pH is a crucial factor governing the binding interactions between DOM and BPA. However, the mechanisms driven the binding process under different pH conditions are still unclear. In this study, the interactions between BPA and humic acids (HA), a primary component of DOM, are investigated over a wide pH range of 3-12 by integrating fluorescence quenching, dynamic light scattering and microcalorimetry. pH dependence of the binding interactions between HA and BPA are interpreted from a thermodynamic perspective. The results indicate that HA can spontaneously interact with BPA to form a stable HA-BPA complex. With the increasing pH, the binding interactions change from entropy driven to entropy-enthalpy co-driven. Hydrophobic force dominate the binding interactions under acidic condition. The synergy of hydrophobic force and hydrogen bond promotes the binding process under neutral condition. Under alkaline conditions, electrostatic repulsion participates the binding process in addition to hydrophobic force and hydrogen bond, weakening the binding strength. Therefore, neutral pH is favorable for HA to bind with BPA, consequently enhancing the dissolution of BPA in natural water bodies. The results are beneficial to better understand the pH dependent distribution of BPA in aquatic environments.


Assuntos
Compostos Benzidrílicos/química , Substâncias Húmicas/análise , Modelos Químicos , Fenóis/química , Poluentes Químicos da Água/química , Calorimetria , Ligação de Hidrogênio , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Termodinâmica
16.
Environ Sci Pollut Res Int ; 26(31): 32589-32599, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31630351

RESUMO

In this paper, a novel structured carbon foam has been prepared from argan nut shell (ANS) was developed and applied in bisphenol A (BPA) removal from water. The results showed that the prepared carbon foam remove 93% of BPA (60 mg/L). The BPA equilibrium data obeyed the Liu isotherm, displaying a maximum uptake capacity of 323.0 mg/g at 20 °C. The calculated free enthalpy change (∆H° = - 4.8 kJ/mol) indicated the existence of physical adsorption between BPA and carbon foam. Avrami kinetic model was able to explain the experimental results. From the regeneration tests, we conclude that the prepared carbon foam has a good potential to be used as an economic and efficient adsorbent for BPA removal from contaminated water. Based on these results and the fact that the developed structured carbon foam is very easy to separate from treated water, it can serve as an interesting material for real water treatment applications.


Assuntos
Compostos Benzidrílicos/química , Carbono/química , Disruptores Endócrinos/análise , Fenóis/química , Adsorção , Biomassa , Disruptores Endócrinos/química , Cinética , Termodinâmica , Poluentes Químicos da Água , Purificação da Água/métodos
17.
Aquat Toxicol ; 216: 105314, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31561137

RESUMO

The endocrine disruptor Bisphenol A (BPA), a widely employed molecule in plastics, has been shown to affect several biological processes in vertebrates, mostly via binding to nuclear receptors. Neurodevelopmental effects of BPA have been documented in vertebrates and linked to neurodevelopmental disorders, probably because some nuclear receptors are present in the vertebrate brain. Similarly, endocrine disruptors have been shown to affect neurodevelopment in marine invertebrates such as ascidians, mollusks or echinoderms, but whether invertebrate nuclear receptors are involved in the mode-of-action is largely unknown. In this study, we assessed the effect of BPA on larval brain development of the ascidian Phallusia mammillata. We found that BPA is toxic to P. mammillata embryos in a dose-dependent manner (EC50: 11.8µM; LC50: 21µM). Furthermore, micromolar doses of BPA impaired differentiation of the ascidian pigmented cells, by inhibiting otolith movement within the sensory vesicle. We further show that this phenotype is specific to other two bisphenols (BPE and BPF) over a bisphenyl (2,2 DPP). Because in vertebrates the estrogen-related receptor gamma (ERRγ) can bind bisphenols with high affinity but not bisphenyls, we tested whether the ascidian ERR participates in the neurodevelopmental phenotype induced by BPA. Interestingly, P. mammillata ERR is expressed in the larval brain, adjacent to the differentiating otolith. Furthermore, antagonists of vertebrate ERRs also inhibited the otolith movement but not pigmentation. Together our observations suggest that BPA may affect ascidian otolith differentiation by altering Pm-ERR activity whereas otolith pigmentation defects might be due to the known inhibitory effect of bisphenols on tyrosinase enzymatic activity.


Assuntos
Compostos Benzidrílicos/toxicidade , Encéfalo/citologia , Encéfalo/embriologia , Diferenciação Celular/efeitos dos fármacos , Organogênese , Fenóis/toxicidade , Pigmentação , Urocordados/citologia , Animais , Compostos Benzidrílicos/química , Movimento Celular/efeitos dos fármacos , Embrião não Mamífero/efeitos dos fármacos , Larva/efeitos dos fármacos , Larva/metabolismo , Organogênese/efeitos dos fármacos , Membrana dos Otólitos/citologia , Membrana dos Otólitos/efeitos dos fármacos , Fenóis/química , Pigmentação/efeitos dos fármacos , Receptores Estrogênicos/antagonistas & inibidores , Receptores Estrogênicos/metabolismo , Testes de Toxicidade , Urocordados/embriologia , Poluentes Químicos da Água/toxicidade
18.
In Vivo ; 33(5): 1421-1423, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31471387

RESUMO

BACKGROUND/AIM: Bisphenol A (BPA) is a ubiquitous substance found in a wide array of consumer products and healthcare consumables, and at low doses in drinking water. Currently, in the UK, it is classed as a low-risk substance with little potential for harm. It has been known to have effects on oestrogen receptors. The implications of this for public safety is currently subject to debate. MATERIALS AND METHODS: In this study, we review recent literature regarding the effects and safety of BPA, and discuss the potential implications, in particular from the perspective of human breast oncogenesis. RESULTS AND CONCLUSION: Recent evidence suggests that low-doses of endocrine disruptors, such as BPA, could have profound effects in breast development and cancer risk. Recent studies in murine models suggest that BPA could contribute to breast oncogenesis via several pathways. The position of regulators should shift accordingly to safeguard the public interest.


Assuntos
Compostos Benzidrílicos/química , Compostos Benzidrílicos/farmacologia , Fenóis/química , Fenóis/farmacologia , Animais , Compostos Benzidrílicos/efeitos adversos , Disruptores Endócrinos/efeitos adversos , Disruptores Endócrinos/química , Disruptores Endócrinos/farmacologia , Exposição Ambiental/efeitos adversos , Humanos , Fenóis/efeitos adversos
19.
Chemosphere ; 236: 124835, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31549673

RESUMO

In this contribution, the electrocatalytic abatement of bisphenol A (BPA) with boron-doped diamond (BDD) anode had been conducted in NaNO2 electrolytes. Central composite design was used as statistical multivariate method to optimize the operating parameters adopted (applied current density, flow rate, concentration of NaNO2 and initial pH). The results from response surface analysis indicated that pH was the most influential factor for TOC decay, and a maximum TOC decay of 63.7% was achieved under the optimized operating conditions (9.04 mA cm-2 of applied current density, 400 mL min-1 of flow rate, 10 mM of NaNO2, 4.0 of initial pH and 60 min of electrolysis time). Besides, LC/MS technique was applied to identify the main reaction intermediates, and plenty of nitrated oligomers were detected at the end of the degradation. These by-products were generated via the coaction of coupling reaction of nitrated phenol and electrophilic substitution mediated by nitrogen dioxide radicals. Moreover, our results showed that the degree of nitration depended heavily on the employed initial nitrite concentration. This was one of the very few investigations dealing with nitrophenolic by-products in nitrite medium, and thus the findings exhibited important implications for electrochemical degradation of BPA and its related phenolic pollutants.


Assuntos
Compostos Benzidrílicos/química , Técnicas Eletroquímicas/métodos , Nitratos/química , Nitritos/química , Fenóis/química , Poluentes Químicos da Água/química , Boro/análise , Diamante , Eletrodos , Eletrólise , Concentração de Íons de Hidrogênio , Nitratos/análise , Nitritos/análise , Oxirredução , Fenóis/análise , Poluentes Químicos da Água/análise
20.
Drug Des Devel Ther ; 13: 2459-2474, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31413543

RESUMO

Introduction: In this study, a dual release bi-layer tablet containing Fesoterodine fumarate (Fst) 5 mg and Mirabegron (Mrb) 50 mg was prepared to investigate the different release behavior of each drug in bilayer tablet. The bilayer tablet was prepared based on monolayer-tablet formulation of each drug. Methods: The optimized bi-layer tablet showed an in vitro dissolution profile similar to commercial reference tablets Toviaz and Betmiga, based on a satisfactory similarity factor. Drug-release kinetics of each drug in the bilayer tablet were evaluated based on dissolution profiles. Drug-release behavior was evaluated by observing the surface of each layer by scanning electron microscopy and measuring the changes in weight and volume of the tablet during dissolution. Drug transfer between each layer was also investigated by Fourier -transform infrared spectroscopic imaging by observing the cross-section of the bilayer tablet cut vertically during dissolution. Results: The release of Fst was well suited for the Higuchi model, and the release of Mrb was well suited for the Hixson-crowell model. Compared with dissolution rate of each monolayer tablet, that of Fst in the bilayer tablet was slightly reduced (5%), but the dissolution rate of Mrb in bilayer tablet was dramatically decreased (20%). Also, a drug-release study confirmed that polymer swelling was dominant in Fst layer compared with polymer erosion, and degradation was dominant in MRB layer. Fourier-transform infrared imaging and 3-D image reconstruction showed that drug transfer in the bilayer tablet correlates with the results of drug-release behavior. Conclusion: These findings are expected to provide scientific insights in the development of a dual-release bilayer drug-delivery system for Fst and Mrb.


Assuntos
Acetanilidas/química , Compostos Benzidrílicos/química , Liberação Controlada de Fármacos , Fumaratos/química , Bicamadas Lipídicas/química , Tiazóis/química , Físico-Química , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Comprimidos
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