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1.
Anticancer Res ; 40(9): 5001-5013, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32878788

RESUMO

AIM: Newly synthesized platinum(IV) complexes with ethylenediamine-N,N'-diacetate ligands (EDDA-type) (butyl-Pt and pentyl-Pt) were investigated against two cancer (A549 lung, and HTB 140 melanoma) and one non-cancerous (MRC-5 embryonic lung fibroblast) human cell lines. MATERIALS AND METHODS: The effects of these agents were compared with those of cisplatin after 6-, 24- and 48-h treatment. Sulforhodamine-B (SRB) assay was performed to estimate the cytotoxic effect, while the inhibitory effect on cell proliferation was measured using 5-bromo-2,-deoxyuridine (BrdU) incorporation assay. Cell cycle analysis was performed by flow cytometry. Type of cell death induced by these agents was determined by electrophoretic analysis of DNA, flow cytometry and by western blot analysis of proteins involved in induction of apoptosis. The effects of gamma irradiation, alone and in combination with platinum-based compounds, were examined by clonogenic and SRB assays. RESULTS: All examined platinum-based compounds had inhibitory and antiproliferative effects on A549 cells, but not on HTB140 and MRC-5 cells. Butyl-Pt, pentyl-Pt and cisplatin arrested the cell cycle in the S-phase and induced apoptotic cell death via regulation of expression of B-cell lymphoma 2 (BCL2) and BCL2-associated X (BAX) proteins. Platinum-based compounds increased the sensitivity of A549 cells to gamma irradiation. Butyl-Pt and pentyl-Pt showed better antitumour effects against A549 cells than did cisplatin, by interfering in cell proliferation and the cell cycle, and by triggering apoptosis. CONCLUSION: The effects of gamma irradiation on tumour cells may be amplified by pre-treatment of cells with platinum-based compounds.


Assuntos
Antineoplásicos/farmacologia , Compostos Organoplatínicos/farmacologia , Radiossensibilizantes/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/efeitos da radiação , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Cisplatino/farmacologia , Relação Dose-Resposta a Droga , Ácido Edético/análogos & derivados , Ácido Edético/química , Raios gama , Humanos , Concentração Inibidora 50 , Compostos Organoplatínicos/síntese química , Compostos Organoplatínicos/química , Radiossensibilizantes/síntese química , Radiossensibilizantes/química
2.
PLoS One ; 15(8): e0237356, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32817618

RESUMO

DESS is a formulation widely used to preserve DNA in biological tissue samples. Although it contains three ingredients, dimethyl sulfoxide (DMSO), ethylenediaminetetraacetic acid (EDTA) and sodium chloride (NaCl), it is frequently referred to as a DMSO-based preservative. The effectiveness of DESS has been confirmed for a variety of taxa and tissues, however, to our knowledge, the contributions of each component of DESS to DNA preservation have not been evaluated. To address this question, we stored tissues of three aquatic taxa, Mytilus edulis (blue mussel), Faxonius virilis (virile crayfish) and Alitta virens (clam worm) in DESS, each component of DESS individually and solutions containing all combinations of two components of DESS. After storage at room temperature for intervals ranging from one day to six months, we extracted DNA from each tissue and measured the percentage of high molecular weight (HMW) DNA recovered (%R) and normalized HMW DNA yield (nY). Here, HMW DNA is defined as fragments >10 kb. For comparison, we also measured the %R and nY of HMW DNA from extracts of fresh tissues and those stored in 95% EtOH over the same time intervals. We found that in cases where DESS performed most effectively (yielding ≥ 20%R of HMW DNA), all solutions containing EDTA were as or more effective than DESS. Conversely, in cases where DESS performed more poorly, none of the six DESS-variant storage solutions provided better protection of HMW DNA than DESS. Moreover, for all taxa and storage intervals longer than one day, tissues stored in solutions containing DMSO alone, NaCl alone or DMSO and NaCl in combination resulted in %R and nY of HMW DNA significantly lower than those of fresh tissues. These results indicate that for the taxa, solutions and time intervals examined, only EDTA contributed directly to preservation of high molecular weight DNA.


Assuntos
DNA/química , Ácido Edético/química , Ácido Edético/farmacologia , Preservação de Tecido/métodos , Animais , Composição de Medicamentos , Peso Molecular
3.
Bull Environ Contam Toxicol ; 105(3): 428-432, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32740744

RESUMO

The accumulation of Cd and Pb in rice grains poses a potential threat to human health, which is a subject of increasing concern across the globe. We examined the effect that foliar spraying of Zn-ethylenediaminetetraacetate (Zn-EDTA) (0.3% and 0.5% w/v) during the early-grain filling stage has on rice grain yield and Cd, Pb, Zn and Fe contents in rice tissues via a field experiment. The grain yield significantly decreased with the foliar application of 0.5% Zn-EDTA. In rice grain, foliar spraying of 0.5% Zn-EDTA significantly decreased the Cd and Pb contents, but increased the Zn and Fe contents. The main reasons for the decrease in the Cd and Pb content in grain were the inhibition of Cd and Pb by roots and the increased Fe content in grain via Zn-EDTA application. The foliar spraying of Zn-EDTA decreased the grain yield and Cd and Pb contents, while increased the Zn and Fe contents in grains.


Assuntos
Cádmio/análise , Ácido Edético/química , Chumbo/análise , Oryza/fisiologia , Poluentes do Solo/análise , Grão Comestível/química , Humanos , Oryza/efeitos dos fármacos , Folhas de Planta/química , Raízes de Plantas/química , Solo , Zinco/análise
4.
DNA Cell Biol ; 39(9): 1473-1477, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32721230

RESUMO

Global antibiotic resistance, driven by intensive antibiotic exposure/abuse, constitutes a serious challenge to all health care, particularly in an era when new antimicrobial development has slowed to a trickle. Recently, we published work demonstrating the discovery and partial mechanism of action of a novel bactericidal agent that is effective against both gram-positive and gram-negative multidrug-resistant bacteria. This drug, called AB569, consists of acidified nitrite (A-NO2-) and EDTA, of which there is no mechanism of resistance. Using both chemistry-, genetic-, and bioinformatics-based techniques, we first discovered that AB569 was able to generate bactericidal levels of nitric oxide (NO), while the EDTA component stabilized S-nitrosyl thiols, thereby furthering NO and downstream reactive nitrogen species production. This elegant chemistry triggered a paralytic downregulation of vital genes using RNA-seq involved in the synthesis of DNA, RNA, ATP, and protein in the representative ESKAPE pathogen, Pseudomonas aeruginosa.


Assuntos
Antibacterianos/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Antibacterianos/química , Farmacorresistência Bacteriana , Ácido Edético/química , Bactérias Gram-Negativas/genética , Bactérias Gram-Positivas/genética , Nitritos/química
5.
Ecotoxicol Environ Saf ; 201: 110807, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32505762

RESUMO

In order to investigate the decrease in total metal contents and to mitigate the availability and toxicity of metals from farmland near a lead mining area, a combination of two effective soil washing and eco-friendly stabilization technologies was applied in current research. The pre-treatment was performed with three types of agents including Ethylenediaminetetraacetic acid (EDTA), citric acid (CA), and mixture of hydroxylamine hydrochloride and citric acid (HA)) and the post-treatment stabilization was adopted using four rich-carbon organic waste amendments (cow manure compost (CMC), vermicompost (VC), urban sewage sludge (SS), and sludge-derived biochar (BIO)). Furthermore, the fate of residual metals (leachability, plant-availability, bioaccessibility, and chemical distribution), soil quality indicators (phytotoxicity and enzyme activities), and some soil physicochemical properties were examined before and after the two-steps remediation. The soil washing, especially using HA and CA agents, dramatically increased the labile metals and negatively changed the soil microbial activity. The two-month stabilization with SS, BIO, and VC resulted in a significant control of the leachability and plant-availability of residual Zn and Pb. However, the post-treatment was only slightly immobilized of Cd. The amendments affected the restoration of soil pH and organic carbon as well as the improvement of available nutrients. Compared to the other amendments that caused restrictions, the SS significantly restored the enzyme activities. With the exception of CMC, the SS, VC, and BIO, indicated higher germination rate and growth of wheat were also obtained. This study reveal the ability of the complementary role of stabilization with soil washing to reduce metal toxicity and confirm the usefulness of municipal and animal wastes in enhancing soil and environmental qualities.


Assuntos
Recuperação e Remediação Ambiental/métodos , Fertilizantes/análise , Metais Pesados/análise , Mineração , Poluentes do Solo/análise , Solo/química , Animais , Bovinos , Carvão Vegetal/química , Ácido Cítrico/química , Compostagem , Ácido Edético/química , Esterco/análise , Metais Pesados/metabolismo , Plantas/metabolismo , Esgotos/química
6.
Chemosphere ; 257: 127226, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32512332

RESUMO

In washing soils contaminated with toxic metals, the replacement of recalcitrant EDTA with biodegradable chelators has gained high expectations. Herein we investigated the feasibility of using EDTA and biodegradable GLDA, EDDS and IDS under conditions pertinent to operational remediation technology, in a pilot-scale experiment. GLDA and IDS did not precipitate from process solutions, which lessened their recyclability. In other process parameters, chelator supplement, Na-saturation of process solutions and processing time, EDTA outperformed biodegradable chelators. Treatment with EDTA was also the most effective in total Pb and Zn removal and least impacted soil properties. GLDA was slightly better in Cd removal. EDDS and IDS were inefficient. All chelators effectively removed easily-available Pb, Zn and Cd from the exchangeable soil fraction. EDTA was the most efficient chelator in reducing the bioaccessibility of Pb and GLDA in reducing the bioaccessibility of Cd from simulated human gastrointestinal tract. Treatment with GLDA had an edge in reducing plant bioaccessibility of toxic metals, but induced worrying leachability of Pb. This was 8.3-times higher than with the process with EDTA and 3.4-times higher than in original soil. In general, our results demonstrate the advantage of EDTA over tested biodegradable chelators in process and remediation efficiency and environmental safety.


Assuntos
Ácido Edético/química , Recuperação e Remediação Ambiental/métodos , Poluentes do Solo/química , Animais , Quelantes , Estudos de Viabilidade , Isópodes , Metais Pesados/análise , Reciclagem , Solo , Poluentes do Solo/análise
7.
Niger J Clin Pract ; 23(5): 697-703, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32367879

RESUMO

Background: The purpose of this study was to assess the quantity of the chelated calcium ions and the smear layer removal efficiency after root canal final irrigation with three different solutions. Materials and Methods: Forty-five teeth were instrumented with rotary-files, then randomly divided into 3 equal groups (n = 15) depending on the final irrigation solution; group I: 17% ethylenediaminetetraacetic acid (EDTA), group II: 0.2% chitosan, and group III: 10% trisodium citrate. According to the time of application, every group was divided into 3 subgroups (1 min, 5 min, and 24 h). The quantification analysis of chelated calcium ions was performed by flame atomic absorption spectrometry (FAAS). Then, the presence of smear layer was examined by splitting the samples longitudinally and using scanning electron microscopy (SEM) to examine coronal, middle, and apical root canal levels. One-way analysis of variance (ANOVA) test was used for the evaluation of treatment effect. Kruskal-Wallis test was executed to detect a significant difference between groups, while Mann-Whitney U test has determined the difference between each two groups for smear layer. Results: Both 17% EDTA and 0.2% chitosan had not been statistically significant difference for smear layer removal efficiency and observed calcium ion concentrations. Although, they were more efficient of 10% trisodium citrate with a significant difference (P < 0.05). Conclusion: The application time of the chelators' solutions must not exceed 5 min to completely remove smear layer, and 0.2% chitosan is a natural substitute for 17% EDTA with a safety application for 24 h.


Assuntos
Quitosana/química , Ácido Edético/química , Irrigantes do Canal Radicular/química , Preparo de Canal Radicular/métodos , Humanos , Microscopia Eletrônica de Varredura , Camada de Esfregaço/diagnóstico por imagem , Camada de Esfregaço/cirurgia , Dente/cirurgia
8.
Chemosphere ; 253: 126574, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32278903

RESUMO

Making municipal sludge into garden soil is a challenging issue in land using due to the high content of heavy metals, however phytoremediation can reduce the heavy metal pollution in the soil. Three artificial regulators were used in combination to improve phytoremediation of heavy metals by Bryophyllum laetivirens from municipal sludge made garden (MSMG) soil. Results showed that B. laetivirens grew well in MSMG soil and bioaccumulated Cu, Pb, Zn, Cd, and Ni by 2.16-11.0 times higher than those grew in local common garden soil. The application of ethylenediaminetetraacetic acid (EDTA), indole-3-acetic acid (IAA) and microbial liquid (BL) promoted the bioaccumulation of heavy metals of plants in MSMG soil, with 2.1-6.8 times than the control group. The optimum dose for the phytoremediation of B. laetivirens was the combining treatment of 3 mmol kg-1 EDTA, 10-10 M IAA, and 5 ml kg-1 BL, which has been successfully applied in MSMG soil. EDTA treatment is more direct and effective in facilitating HM uptake of root, while the other two treatments play important roles in promoting the transport of HMs in plants.


Assuntos
Biodegradação Ambiental , Kalanchoe/fisiologia , Metais Pesados/metabolismo , Poluentes do Solo/metabolismo , Ácido Edético/química , Jardinagem , Jardins , Ácidos Indolacéticos , Metais Pesados/análise , Plantas , Esgotos/química , Solo/química , Poluentes do Solo/análise
9.
Food Chem ; 319: 126432, 2020 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-32172045

RESUMO

The main aim of the present study was the measurement of nickel metal ion in the real samples of crab, oyster and rice by the designed magnetic nano adsorbent silk fibroin-EDTA ligand (SF-Fe3O4-EDTA). Due to the structure of silk fibroin (possessing lots of functional groups which are suitable for attachment of ligands and high surface area), it was used in the structure of fabricated nano-adsorbent. To follow the fabrication processes of the magnetic nano-adsorbent, different techniques of fourier-transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-Visible), vibrating sample magnetometer (VSM), and field emission scanning electron microscopy (FE-SEM) were used. The optimization processes were performed with the chemometric method of response surface modeling with sufficient accuracy and precision. Using this chemometric method, the optimum values of pH, absorption time, the concentration of nano-adsorbent and temperature were calculated to be 6, 21 min, 4 mg L-1 and 28 °C, respectively. Due to the magnetic nature of the constructed nano-adsorbent, a magnet bar was used to separate the nano-adsorbent from the solution and then inject to the furnace atomic absorption device. Using the magnetic nano-adsorbent of silk fibroin-EDTA ligand and furnace atomic absorption a detection limit of 0.0017 µg L-1 and a linear range of 0.0030-5.0 µg L-1 for determination of nickel metal ion were obtained. The determination of nickel metal ion in the crab tissue, oyster tissue and rice samples were performed and the obtained results revealed the successful applicability of the designed method for determination of nickel metal ion in the real samples.


Assuntos
Braquiúros/química , Fibroínas/química , Níquel/análise , Oryza/química , Frutos do Mar , Animais , Ácido Edético/química , Ligantes , Limite de Detecção , Magnetismo , Imãs , Espectrofotometria Atômica
10.
Food Chem ; 318: 126506, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32126473

RESUMO

Orange peels were applied as precursors to synthesize carbon dots (CDs) via a one-step green hydrothermal method. The relationship between quantum yield and volatile oils in 14 different varieties of orange peels were investigated. The CDs showed strong blue fluorescence and were further modified with EDTA. Compared with the CDs, the CDs@EDTA exhibited higher sensitivity for Cr(VI) detection with a LOD of 10 nM. The CDs@EDTA was proved to be an effective fluorescent sensor element for Cr(VI) detection in water samples with recoveries ranged from 92.09% to 104.87% (RSD < 5%). Moreover, CDs@EDTA/Cr(VI) system was further developed as a fluorescent "off-on" sensor for ascorbic acid (AA) detection with a LOD of 0.1 µM. Further, the sensor had been successfully applied for the analysis of AA in fresh oranges and commercial orange juices. The recoveries of AA in fresh oranges and orange juices were 92.58-106.76% and 91.54-104.95%, respectively.


Assuntos
Ácido Ascórbico/análise , Carbono/química , Citrus sinensis/química , Sucos de Frutas e Vegetais/análise , Espectrometria de Fluorescência/métodos , Cromo/química , Ácido Edético/química , Fluorescência , Frutas/química , Pontos Quânticos/química , Sensibilidade e Especificidade
11.
Proc Natl Acad Sci U S A ; 117(9): 4921-4930, 2020 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-32071223

RESUMO

Antibiotic-resistant superbug bacteria represent a global health problem with no imminent solutions. Here we demonstrate that the combination (termed AB569) of acidified nitrite (A-NO2 -) and Na2-EDTA (disodium ethylenediaminetetraacetic acid) inhibited all Gram-negative and Gram-positive bacteria tested. AB569 was also efficacious at killing the model organism Pseudomonas aeruginosa in biofilms and in a murine chronic lung infection model. AB569 was not toxic to human cell lines at bactericidal concentrations using a basic viability assay. RNA-Seq analyses upon treatment of P. aeruginosa with AB569 revealed a catastrophic loss of the ability to support core pathways encompassing DNA, RNA, protein, ATP biosynthesis, and iron metabolism. Electrochemical analyses elucidated that AB569 produced more stable SNO proteins, potentially explaining one mechanism of bacterial killing. Our data implicate that AB569 is a safe and effective means to kill pathogenic bacteria, suggesting that simple strategies could be applied with highly advantageous therapeutic/toxicity index ratios to pathogens associated with a myriad of periepithelial infections and related disease scenarios.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Ácido Edético/farmacologia , Nitrito de Sódio/farmacologia , Animais , Antibacterianos/uso terapêutico , Biofilmes/efeitos dos fármacos , Modelos Animais de Doenças , Regulação para Baixo , Farmacorresistência Bacteriana/efeitos dos fármacos , Ácido Edético/química , Pneumopatias/tratamento farmacológico , Pneumopatias/microbiologia , Redes e Vias Metabólicas , Camundongos , Nitritos/química , Nitritos/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos
12.
Chemosphere ; 243: 125439, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31995887

RESUMO

This paper introduces a novel method for ethylenediaminetetraacetic acid (EDTA)-enhanced electrokinetic (EK) remediation by combining dual cation-exchange membranes and circulation methods for an aged electroplating soil contaminated by chrome (Cr), copper (Cu), and nickel (Ni). Three laboratory-scale EK experiments were carried out, including T1, the traditional EK process; T2, the traditional EDTA-enhanced EK process; and T3, the assisted EDTA-enhanced EK process. The results obtained show that removal of Cu and Ni in T3 was 3-10 times higher than after T1 and T2. However, the removal of Cr (total) was small in all experiments because of the high content of Cr(III). T3 eliminated the metal accumulation problem that existed for T1 and T2. Simultaneously, the highly acidified area (pH < 4) was reduced from 80% in T1 and T2 to only 20% in T3. The results obtained in T3 indicate that the chelating effect of EDTA has a greater ability to dissolve oxidizable Cu and Ni in the soil than the acidification effect. Toxicity evaluation confirmed that the soil treated by T3 presented a lower effect on a luminescent bacterium (Photobacterium phosphoreum T3) because soil pH tended to be more neutral after this treatment. This research provides a novel method for removing heavy metals from soil in a more environmentally friendly way and clarifies the cause of the existing problems of low removal efficiency and high accumulation in the traditional EK process.


Assuntos
Técnicas Eletroquímicas/métodos , Recuperação e Remediação Ambiental/métodos , Resinas de Troca de Cátion , Compostos de Cromo/isolamento & purificação , Cobre/química , Cobre/isolamento & purificação , Ácido Edético/química , Galvanoplastia , Metais Pesados/isolamento & purificação , Níquel/isolamento & purificação , Solo/química , Poluentes do Solo/isolamento & purificação
13.
Artigo em Inglês | MEDLINE | ID: mdl-31941097

RESUMO

Adding chelating agents is a critical technique of heavy metal activation for enhancing phytoextraction through the formation of soluble metal complexes which will be more readily available for extraction. The preliminary, dynamic, equilibrium activation experiments and speciation analysis of Pb, Cd and Tl in contaminated red soils were used to select six chelates with relatively good activation performance from nine chelates, and the effects of dosage and pH on the heavy metals activation were studied systematically. Results showed that the activation of Pb, Cd and Tl by chelates reached equilibrium within 2 h, and the activation process showed three stages. Under neutral conditions, chelates had better activation performance on Pb- and Cd-contaminated soils. Except for S,S-ethylenediamine disuccinic acid (S,S-EDDS) and citric acid (CA), the maximum equilibrium activation effect (MEAE) of ethylenediaminetetraacetic acid (EDTA), N,N-bis (carboxymethyl) glutamic acid (GLDA), diethylenetriaminepentaacetic acid (DTPA) and aminotriacetic acid (NTA) was over 81%. The MEAE of Tl-contaminated soil was less than 15%. The decreasing order of the dosage of chelating agents corresponding to MEAE for three types of contaminated soils was Pb-, Cd- and Tl-contaminated soil, relating to the forms of heavy metals, the stability constants of metal-chelates and the activation of non-target elements Fe in red soil. Under acidic conditions, the activation efficiencies of chelates decreased to differing degrees in Pb- and Cd-contaminated soils, whereas the activation efficiencies of chelating agents in Tl-contaminated soils were slightly enhanced.


Assuntos
Cádmio/química , Quelantes/química , Chumbo/química , Poluentes do Solo/química , Tálio/química , Biodegradação Ambiental , Ácido Cítrico/química , Ácido Edético/química , Etilenodiaminas/química , Glutamatos/química , Glicina/análogos & derivados , Glicina/química , Ácido Pentético/química , Solo/química , Succinatos/química
14.
Ecotoxicol Environ Saf ; 191: 110185, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31986455

RESUMO

Landscaping of sludge is a kind of recycling disposal, but the potential heavy metal risks limit its application. In this paper, the sludge soil was remediated by ryegrass, and the effect of ethylene diamine tetraacetic acid (EDTA) was studied through pot experiments. Italian ryegrass was planted in the sludge soil treated with six gradients concentrations of 0, 1, 2, 3, 4, 5 mmol kg-1 of EDTA, and the planting conditions were kept the same. After 45 days of planting, compared with the control group (without EDTA treated), the application of 1-5 mmol kg-1 EDTA decreased ryegrass biomass by 2-43%, reduced soil pH value by 0.21-0.34 unit, and reduced 4.1-9.7% capacity of exchange cation, but increased 1.4-8.6% soil organic matter. After growing ryegrass, the contents of heavy metals decreased by 10% for Cu, 15% for Zn, 6% for Ni, 14% for Cd and 44% for Pb; and after spraying EDTA decreased again by 33% for Cu, 31% for Zn, 56% for Ni, 24% for Cd, and 68% for Pb. In ryegrass, the uptake heavy metals were enhanced, and bio-concentration factor of Cu, Zn, Ni, Cd, and Pb of EDTA treated groups were 1.9, 1.6, 4.1, 2.7, and 4.8 times of the control group, respectively. However, EDTA only significantly increased transfer factor values of Cu and Zn, and made bio-extraction factor value of Cu greater than 1. The remediation factor values were used to comprehensive assess accumulation capacity of heavy metals by ryegrass under EDTA treating, and they ordered in Zn > Cu > Ni > Cd > Pb, and the best dose was 2 mmol kg-1 EDTA. Prediction models for bio-concentration factor were established by using stepwise multiple linear regression, explaining 94.9-99.3% of the corresponding elements with soil organic matter, EDTA dosage, and/or pH value (p < 0.005). This paper provided effective heavy metals remediation data for municipal sludge landscape and the prediction models.


Assuntos
Ácido Edético/química , Lolium/metabolismo , Metais Pesados/metabolismo , Poluentes do Solo/metabolismo , Eliminação de Resíduos Líquidos/métodos , Biodegradação Ambiental , Biomassa , Itália , Lolium/crescimento & desenvolvimento , Metais Pesados/análise , Metais Pesados/química , Esgotos/química , Solo/química , Poluentes do Solo/análise , Poluentes do Solo/química
15.
Food Chem ; 310: 125741, 2020 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-31806389

RESUMO

Polyphenol oxidase (PPO), also known as tyrosinase and catechol oxidase, is the enzyme responsible for enzymatic browning in foods. It causes undesirable organoleptic, nutritional and colour changes. Here, we report the preparation of five nanomaterials and a study of their ability to modulate PPO enzyme activity. The materials consist of UVM-7 supports (a mesoporous silica material) modified with diverse functional groups (i.e. amine, carboxylic acid, isocyanate, alkane and pyridine). We also studied the PPO immobilisation capability of the materials. All the materials, except the carboxylic acid functionalised one, offer high PPO loading capabilities and the immobilisation speed increases with functionalisation. Nevertheless, only a minor effect of the inhibition of enzymatic browning was produced. Furthermore, the amine containing material was able to capture not only PPO, but also the oxidation products. Such behaviour was validated with fresh apple juice in which browning was avoided, even 90 min in the presence of oxygen at room temperature.


Assuntos
Catecol Oxidase/química , Catecol Oxidase/metabolismo , Sucos de Frutas e Vegetais , Nanoestruturas/química , Dióxido de Silício/química , Ácidos Carboxílicos/química , Ácido Edético/química , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Malus/química , Oxirredução , Oxigênio/química , Oxigênio/metabolismo , Piridinas/química , Propriedades de Superfície
16.
J Appl Oral Sci ; 28: e20190005, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31800870

RESUMO

other: Chitosan is a natural, biocompatible chelating substance with potential for dental use. This study compared the effects of final canal irrigation with chitosan and EDTA on dentin microhardness, sealer dentin tubules penetration capacity, and push-out strength. METHODOLOGY: Fifty canine roots were distributed according to the final irrigation protocol (n=10): G1- 15% EDTA with conventional irrigation; G2- 15% EDTA with Endovac; G3- 0.2% chitosan with conventional irrigation; G4- 0.2% chitosan with Endovac; and G5- without irrigation. Specimens were obturated (AH Plus) and sectioned in 3 slices per root third. The first slice was used for microhardness and sealer penetration assessments under a laser confocal microscope. The second was utilized in a push-out strength test. The third slice was discarded. Data were analyzed using 2-way ANOVA and Tukey's post hoc test (α<0.05). Failure mode was determined at x40 magnification. RESULTS: Microhardness reduction was more significant in groups G2 and G4 (p<0.05). Sealer penetration through dentin was significantly greater in group G2 (p<0.05). There was no significant difference between groups G1, G3, and G4 (p>0.05). In general, all experimental groups presented similar bond resistance (p>0.05) that significantly differed from the control (p<0.001). Mixed type failures were predominant. CONCLUSIONS: In general, 0.2% chitosan and 15% EDTA solutions act in a similar manner with regard to the variables studied. The use of Endovac potentiates the effect of these solutions.


Assuntos
Quelantes/química , Quitosana/química , Colagem Dentária/métodos , Dentina/efeitos dos fármacos , Ácido Edético/química , Irrigantes do Canal Radicular/química , Análise de Variância , Resinas Epóxi/química , Testes de Dureza , Humanos , Teste de Materiais , Microscopia Confocal , Pessoa de Meia-Idade , Valores de Referência , Reprodutibilidade dos Testes , Materiais Restauradores do Canal Radicular/química , Resistência ao Cisalhamento , Propriedades de Superfície/efeitos dos fármacos
17.
Bull Environ Contam Toxicol ; 104(1): 128-133, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31728557

RESUMO

Ethylenediaminetetraacetic acid disodium salt (EDTA) was selected among various eluents due to its highest removal efficiency for lead (Pb) (43.7%) and zinc (Zn) (57.1%) leaching from Pb-Zn contaminated soil by soil column experiment. Compared with newly prepared EDTA eluent, using recycled EDTA eluent can still leaching down 71.1% of Pb and 63.2% of Zn respectively, which showed the reusable benefits of recycled EDTA eluent. After soils were leached by EDTA, soil quality decline, such as reducing of urease, catalase, invertase activities and microorganism numbers. However, adding 5% nutrition soil or earthworm fertilizer can significantly improve the quality of EDTA leached soil, and promote growth of peas and ryegrass compared with EDTA treatments. Overall, the improvement of EDTA leached soil by adding nutrition soil or earthworm fertilizer is important, and recycled EDTA eluent can recycle and re-use for Pb-Zn contaminated soil remediation.


Assuntos
Recuperação e Remediação Ambiental/métodos , Reciclagem , Poluentes do Solo/análise , Ácido Edético/química , Solo , Zinco/química
18.
Environ Sci Pollut Res Int ; 27(1): 812-822, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31811611

RESUMO

In this study, ozone-oxidation was used to treat synthetic chemical plating solution containing Cu(II)/Ni(II)-EDTA solution to realize the purpose of decomplexation. The effects of solution pH, initial concentration of Cu(II)/Ni(II)-EDTA, the molar ratio of EDTA to Cu(II)/Ni(II), and the coexistence of Cu(II)/Ni(II) on their removal efficiencies were investigated. The degradation of EDTA-Cu(II) and EDTA-Ni(II) were mainly attributed to OH oxidation, and the removal rates of Cu(II)/Ni(II) depend on the complete decomplexation. The removal rates of Cu(II) and Ni(II) was affected by the pH of solution, and the optimal pH was found to be 7-9; nevertheless, their removal rates can still be up to 90% even in acidic pHs of 3~5. When the molar ratio of EDTA to Cu(II)/Ni(II) increased from 1:1 to 3:1, the kinetics of metal ion removal rate declined from 0.0788 and 0.1139 min-1 to 0.0250 and 0.0271 min-1. The synergistic effect was found in the Cu(II)/Ni(II) blended system due to the higher catalytic capability and the lower complexation affinity toward EDTA for Ni(II). In summary, ozone oxidation can be considered as an effective technology to realize the complete decomplexation of Cu(II)/Ni(II)-EDTA that contained in chemical plating industry wastewater. Graphical Abstract.


Assuntos
Cobre/química , Ácido Edético/química , Ozônio/química , Catálise , Cinética , Oxirredução
19.
Mater Sci Eng C Mater Biol Appl ; 106: 110283, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31753393

RESUMO

The aim of this study was to characterize glycolic acid (GA) and examine its effects on powder and flexural strength of dentin. Particle size and energy-dispersive EDS in GA powder was performed for chemical analysis. Surface tension and pH levels of ethylenediaminetetraacetic acid (EDTA), citric acid (CA), and GA solutions were evaluated at different times and temperatures. Dentin powder and mineralized dentin beams were immersed for 1 min in EDTA, CA, or GA solutions and subjected to Fourier transform infrared spectroscopy for apatite/collagen ratio analysis and 3-point flexure test, respectively. GA showed the largest particle size (µm), and its surface tension was similar to that of EDTA and CA. Surface tension decreased in solutions of higher concentrations. GA showed pH stability at all times and temperatures evaluated. The apatite/collagen ratio reduced with increased GA concentrations, while flexural strength was not significantly affected by GA concentration. GA seems a good choice as a final irrigation solution after root canal preparation.


Assuntos
Dentina/química , Glicolatos/química , Ácido Cítrico/química , Colágeno/química , Colágeno/metabolismo , Cavidade Pulpar/efeitos dos fármacos , Dentina/efeitos dos fármacos , Ácido Edético/química , Resistência à Flexão , Glicolatos/farmacologia , Humanos , Concentração de Íons de Hidrogênio , Tamanho da Partícula , Desnaturação Proteica , Irrigantes do Canal Radicular/química , Irrigantes do Canal Radicular/farmacologia , Tensão Superficial , Temperatura
20.
Chemosphere ; 239: 124722, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31494318

RESUMO

Perfluorooctanoic acid (PFOA) has attracted considerable attention worldwide due to its widespread occurrence and environmental impacts. This research focused on the photocatalytic process for the treatment of PFOA in water and wastewater. Gallium oxide (Ga2O3) and peroxymonosulfate (PMS) were mixed directly in PFOA solution, which was irradiated under different light sources. The treatment system showed excellent performance that 100% PFOA was degraded within 90 min and 60 min under 254 nm and 185 nm UV irradiation, respectively. Moreover, the degradation efficacy was unaffected by initial PFOA concentration from 50 ng L-1 to 50 mg L-1. Acidic solution (pH 3) improved the degradation process. The quantum yield in the PMS/Ga2O3 system under UV light (254 nm) was estimated to be 0.009 mol E-1. Scavengers such as tert-butanol (t-BuOH), disodium ethylenediaminetetraacetate (EDTA-Na2) and benzoquinone (BQ) were added into PFOA solution to prove that sulfate radicals (SO4•-), superoxide radical (O2•-) and photogenerated electrons (e-) were the main active species with strong redox ability for PFOA degradation in PMS/Ga2O3/UV system. Combined with the intermediates analysis, PFOA was degraded stepwise from long chain compound to shorter chain intermediates. In addition, PFOA in real wastewater exhibited similar degradation efficiency, together with 75-85% TOC removal by Ga2O3/PMS under 254 nm UV irradiation. Therefore, Ga2O3/PMS system was highly effective for PFOA photodegradation under UV irradiation, which has potential to be applied for the perfluoroalkyl substances (PFAS) treatment in water and wastewater.


Assuntos
Caprilatos/química , Fluorcarbonetos/química , Gálio/química , Peróxidos/química , Poluentes Químicos da Água/química , Benzoquinonas/química , Ácido Edético/química , Concentração de Íons de Hidrogênio , Oxirredução , Fotólise , Superóxidos/química , Raios Ultravioleta , Águas Residuárias/química , Água , Purificação da Água , Difração de Raios X
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