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1.
Ecotoxicol Environ Saf ; 214: 112064, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33691241

RESUMEN

Hydrophyte decomposition caused large amounts of dissolved organic matter (DOM) to enter aquatic environment that influence the migration and transformation of heavy metals (HMs). Six hydrophytes with five dry weight gradients (DWG) were used for the decomposition experiments. The results showed that protein-like materials occupy relatively high content in the hydrophyte-derived DOM. The binding properties of DOM-Cu(II) have been explored by using two-dimensional correlation spectroscopy (2D-COS) in conjunction with synchronous fluorescence spectroscopy (SFS) and log-transformed SFS. The weak signals of binding site can be amplified by the log-transformed 2D-COS analysis. Herein, more binding sites can be identified by the log-transformed 2D-COS analysis. The results reveal that tryptophan-like materials show a preferential sequence of binding Cu(II) in the hydrophyte-derived DOM with a relatively low DWG and sediment DOM, and fulvic-like substances indicate a preferential sequence of binding Cu(II) in the hydrophyte-derived DOM with a relatively high DWG. Meanwhile, the results of binding parameters indicate that the log K is the range of 3.61-4.25, 4.33-4.74, 4.59-4.97, 3.91-4.41, and 4.14-4.78 for D1-D5, respectively, suggesting that hydrophyte decomposition can change the binding affinity between DOM components and Cu(II). The complexes of fluorescent components with Cu(II) showed a high log K value at long wavelength (e.g. humic-like substances), and a relatively low fluorescent ligand proportion (f%) at shorter wavelength in the hydrophyte-derived DOM. However, the log K is the range of 3.08-4.31, 4.09-4.45, 3.93-4.35, 4.39-4.75, and 3.95-4.36 for C1-C5, separately. Protein-like substances with Cu(II) showed a relatively high log K value with the exception of C4. The log-transformed 2D-COS can be an analytical tool to understand the binding heterogeneity of DOM with HMs. The study can provide a guide for managing and controlling the effects of hydrophyte decomposition.


Asunto(s)
Cobre/metabolismo , Contaminantes Químicos del Agua/metabolismo , Colorantes , Cobre/química , Sustancias Húmicas/análisis , Metales Pesados/química , Espectrometría de Fluorescencia/métodos
2.
Molecules ; 26(4)2021 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-33672487

RESUMEN

Recently, N-substituted anilines have been the object of increasing research interest in the field of organic chemistry due to their role as key intermediates for the synthesis of important compounds such as polymers, dyes, drugs, agrochemicals and pharmaceutical products. Among the various methods reported in literature for the formation of C-N bonds to access secondary anilines, the one-pot reductive amination of aldehydes with nitroarenes is the most interesting procedure, because it allows to obtain diverse N-substituted aryl amines by simple reduction of nitro compounds followed by condensation with aldehydes and subsequent reduction of the imine intermediates. These kinds of tandem reactions are generally catalyzed by transition metal-based catalysts, mainly potentially reusable metal nanoparticles. The rapid growth in the last years in the field of metal-based heterogeneous catalysts for the one-pot reductive amination of aldehydes with nitroarenes demands for a review on the state of the art with a special emphasis on the different kinds of metals used as catalysts and their recyclability features.


Asunto(s)
Aldehídos/química , Compuestos de Anilina/síntesis química , Metales Pesados/química , Nitrocompuestos/química , Compuestos de Anilina/química , Catálisis , Estructura Molecular
3.
Food Chem ; 345: 128864, 2021 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-33601663

RESUMEN

The aim of this study was to determine the physicochemical parameter changes, aroma, melissopalynological properties, and heavy metal content of honey produced from different types of flora (chestnut and highland) in the Senoz Valley. For this purpose, the distribution of beehives at different elevation levels in the research area was determined by a layered random sampling method. Some characteristics of the honey samples were analyzed by standard laboratory methods. The highest average color (L and b) and the glucose, sucrose, Brix, Cd, Pb, Ni, Zn, and Cr values were found in the highland honeys; the highest color (a) and fructose, F/G ratio, proline, pH, conductivity, Fe, Cu, Al, and Mn values were found in the chestnut honeys. The difference between highland and chestnut honeys was statistically significant in terms of color (L and a), F/G ratio, proline, pH, electrical conductivity, Pb, Cu, and Mn. A total of 146 aromatic components were isolated in the chestnut and highland honeys.


Asunto(s)
Miel/análisis , Nueces/química , Color , Flores/química , Flores/metabolismo , Fructosa/análisis , Cromatografía de Gases y Espectrometría de Masas , Metales Pesados/análisis , Metales Pesados/química , Nueces/metabolismo , Turquia , Compuestos Orgánicos Volátiles/análisis
4.
ACS Appl Mater Interfaces ; 13(7): 8082-8094, 2021 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-33570927

RESUMEN

Antibiotic-resistant bacteria are a significant and growing threat to human health. Recently, two-dimensional (2D) nanomaterials have shown antimicrobial activity and have the potential to be used as new approaches to treating antibiotic resistant bacteria. In this Research Article, we exfoliate transition metal dichalcogenide (TMDC) nanosheets using synthetic single-stranded DNA (ssDNA) sequences, and demonstrate the broad-spectrum antibacterial activity of MoSe2 encapsulated by the T20 ssDNA sequence in eliminating several multidrug-resistant (MDR) bacteria. The MoSe2/T20 is able to eradicate Gram-positive Escherichia coli and Gram-positive Staphylococcus aureus at much lower concentrations than graphene-based nanomaterials. Eradication of MDR strains of methicillin-resistant S. aureus (MRSA), Enterococcus faecalis, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Acinetobacter baumannii are shown to occur at at 75 µg mL-1 concentration of MoSe2/T20, and E. coli at 150 µg mL-1. Molecular dynamics simulations show that the thymine bases in the T20 sequence lie flat on the MoSe2 surface and can, thus, form a very good conformal coating and allow the MoSe2 to act as a sharp nanoknife. Electron microscopy shows the MoSe2 nanosheets cutting through the cell membranes, resulting in significant cellular damage and the formation of interior voids. Further assays show the change in membrane potential and reactive oxygen species (ROS) formation as mechanisms of antimicrobial activity of MoSe2/T20. The cellular death pathways are also examined by mRNA expression. This work shows that biocompatible TMDCs, specifically MoSe2/T20, is a potent antimicrobial agent against MDR bacteria and has potential for clinical settings.


Asunto(s)
Antibacterianos/farmacología , Calcógenos/farmacología , ADN de Cadena Simple/química , Farmacorresistencia Bacteriana Múltiple/efectos de los fármacos , Metales Pesados/farmacología , Células A549 , Acinetobacter baumannii/efectos de los fármacos , Antibacterianos/química , Cápsulas/química , Cápsulas/farmacología , Calcógenos/química , ADN de Cadena Simple/síntesis química , Enterococcus faecalis/efectos de los fármacos , Humanos , Klebsiella pneumoniae/efectos de los fármacos , Metales Pesados/química , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Tamaño de la Partícula , Pseudomonas aeruginosa/efectos de los fármacos , Especies Reactivas de Oxígeno/análisis , Especies Reactivas de Oxígeno/metabolismo , Propiedades de Superficie
5.
Molecules ; 26(3)2021 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-33498661

RESUMEN

The quality of water is continuously under threat as increasing concentrations of pollutants escape into the aquatic environment. However, these issues can be alleviated by adsorbing pollutants onto adsorbents. Chitosan and its composites are attracting considerable interest as environmentally acceptable adsorbents and have the potential to remove many of these contaminants. In this review the development of chitosan-based adsorbents is described and discussed. Following a short introduction to the extraction of chitin from seafood wastes, followed by its conversion to chitosan, the properties of chitosan are described. Then, the emerging chitosan/carbon-based materials, including magnetic chitosan and chitosan combined with graphene oxide, carbon nanotubes, biochar, and activated carbon and also chitosan-silica composites are introduced. The applications of these materials in the removal of various heavy metal ions, including Cr(VI), Pb(II), Cd(II), Cu(II), and different cationic and anionic dyes, phenol and other organic molecules, such as antibiotics, are reviewed, compared and discussed. Adsorption isotherms and adsorption kinetics are then highlighted and followed by details on the mechanisms of adsorption and the role of the chitosan and the carbon or silica supports. Based on the reviewed papers, it is clear, that while some challenges remain, chitosan-based materials are emerging as promising adsorbents.


Asunto(s)
Quitosano/química , Contaminantes Químicos del Agua/química , Agua/química , Adsorción , Quitina/química , Grafito/química , Humanos , Metales Pesados/química , Dióxido de Silicio/química , Purificación del Agua/métodos
6.
Ecotoxicol Environ Saf ; 208: 111756, 2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-33396079

RESUMEN

To deeply assess the feasibility of sewage sludge-based biochars for use in soil applications, this review compared sewage sludge-based biochars (SSBBs) with lignocellulose-based biochars (LCBBs) in terms of their pyrolysis processes, various fractions and potential soil applications. Based on the reviewed literature, significant differences between the components of SSBB and LCBB result in different pyrolysis behavior. In terms of the fractions of biochars, obvious differences were confirmed to exist in the carbon content, surface functional groups, types of ash fractions and contents of potential toxic elements (PTEs). However, a clear influence of the feedstock on labile carbon and polycyclic aromatic hydrocarbons (PAHs) was not observed in the current research. These differences determined subsequent discrepancies in the soil application potential and corresponding mechanisms. The major challenges facing biochar application in soils and corresponding recommendations for future research were also addressed. LCBBs promote carbon sequestration, heavy metal retention and organic matter immobilization. The application of SSBBs is a promising approach to improve soil phosphorus fertility, immobilize heavy metals and provide available carbon sources for soil microbes to stimulate microbial biomass. The present review provides guidance information for selecting appropriate types of biochars to address targeted soil issues.


Asunto(s)
Carbón Orgánico/química , Restauración y Remediación Ambiental/métodos , Metales Pesados/química , Pirólisis , Contaminantes del Suelo/química , Biomasa , Carbono , Lignina , Metales Pesados/análisis , Hidrocarburos Policíclicos Aromáticos , Aguas del Alcantarillado , Suelo , Contaminantes del Suelo/análisis
7.
Ecotoxicol Environ Saf ; 208: 111634, 2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-33396154

RESUMEN

The Quantitative Structure-Activity Relationship (QSAR) has been used to investigate organic mixtures but QSAR in the nanomaterial field (QNAR) is still new. Toxicity is a result of the interaction of many substances. QNAR research focuses on a single nanomaterial in the long-term. It is difficult to find an appropriate descriptor to build a model due to the complexity of the mixture. Here, we attempt to build a QNAR model to predict cell viability for HK-2 cells exposed to a mixture containing nano-TiO2 and heavy metals. HK-2 cells were exposed to four groups of mixtures containing heavy-metals and nanomaterials and CCK8 was added to obtain the number of living cells. At the same time, ROS was investigated to study this mechanism. Each descriptor of the components and mixtures were obtained using the formula Dmix= [Formula: see text] respectively. We used the Multiple Partial Least Squares Regression (PLS) and Random Forest Regression (RF) to build a QNAR model. Both models reliably predict and assess viability of HK-2 cells exposed to the mixture. The RF model showed greater stability and higher precision in toxicity predictability and can be applied to environmental nano-toxicology.


Asunto(s)
Ecotoxicología/métodos , Metales Pesados/toxicidad , Nanoestructuras/toxicidad , Relación Estructura-Actividad Cuantitativa , Titanio/toxicidad , Línea Celular , Supervivencia Celular/efectos de los fármacos , Humanos , Metales Pesados/química , Nanoestructuras/química , Especies Reactivas de Oxígeno/metabolismo , Titanio/química
8.
Ecotoxicol Environ Saf ; 208: 111704, 2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-33396035

RESUMEN

Clay minerals can adsorb both microorganisms and heavy metals. In this study, typical soil bacterium, Enterobacter sp. was applied to investigate the potential protection of the bacterial cells from Pb2+ stress by clay minerals. The sorption by two representative types of montmorillonite (Mt) were contrasted, i.e., Mts/Mtw with strong/weak CEC. There was no significant difference between the two clay minerals regarding their adsorption of Pb2+ cations in water (i.e., ~55 mg L-1). However, the sorption of bacterial cells on the two clay minerals showed evident contrasts, which resulted in the different capacity of Pb sorption. Mts with high CEC preferentially adsorbed abundant bacterial cells (rather than Pb2+) on its surface. The residual Pb2+ concentration in solution actually raised by 7.5% after the addition of Enterobacter sp. In addition, both the Pb-contaminated cells and "healthy" cells (with low Pb contamination) could be adsorbed onto Mt surface, whereas the latter dominated the adsorbents on Mts. This was due to that the Mts with high CEC could provide more exchangeable cations, building more cation bridging ligands between the microbial cells (whatever the types of cells) and clay surface. Furthermore, the adsorbed "healthy" bacterial cells might escape from clay surface via "self-liberating" mechanism, i.e., increasing electrostatic repulsion between the bacteria and clay during microbial decomposition of the medium. This study hence elucidated the protection of microorganisms from Pb2+ stress by Mt.


Asunto(s)
Arcilla/química , Enterobacter/efectos de los fármacos , Plomo/toxicidad , Contaminantes del Suelo/toxicidad , Adsorción , Bentonita/química , Cationes/química , Enterobacter/metabolismo , Plomo/química , Metales Pesados/química , Minerales/química , Contaminantes del Suelo/química
9.
Anal Chem ; 93(4): 1880-1888, 2021 02 02.
Artículo en Inglés | MEDLINE | ID: mdl-33430590

RESUMEN

This Feature summarizes recent works in paper-based potentiometry and voltammetry in heavy metal determination. Interactions of paper substrates with heavy metals, influence on the sensing response, and modification methods applied to paper substrates to improve the performance of recently developed electrochemical sensors are discussed. Since the rekindling of interest in paper-based analytical devices, methodologies and electrode designs for heavy metal determinations are highlighted. Promising aspects of the use of these sensors for samples containing solids and the increased versatility of the use of paper in analytics offers the possibility of increased acceptance of these low-cost platforms.


Asunto(s)
Técnicas Electroquímicas/métodos , Metales Pesados/química , Papel , Técnicas Electroquímicas/economía , Técnicas Electroquímicas/instrumentación , Monitoreo del Ambiente/instrumentación , Monitoreo del Ambiente/métodos
10.
Chemosphere ; 262: 127838, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32768756

RESUMEN

Nitrogen and heavy metals can co-occur in various industrial wastewaters such as coke-oven wastewater. Removal of these contaminants is important, but cost-efficient removal technology is limited. In this study, we examined the usefulness of nitrate-dependent ferrous iron oxidation (NDFO) for the simultaneous removal of nitrate and heavy metals (iron and zinc), by using an NDFO strain Pseudogulbenkiania sp. NH8B. Based on the batch culture assays, nitrate, Fe, and Zn were successfully removed from a basal medium as well as coke-oven wastewater containing 5 mM nitrate, 10 mM Fe(II), and 10 mg/L Zn. Zinc in the water was most likely co-precipitated with Fe(III) oxides produced during the NDFO reaction. Simultaneous removal of nitrate, Fe, and Zn was also achieved in a continuous-flow reactor fed with a basal medium containing 10 mM nitrate, 5 mM Fe(II), 4 mM acetate, and 10 mg/L Zn. However, when the reactor is fed with coke-oven wastewater supplemented with 10 mM nitrate, 5 mM Fe(II), 4 mM acetate, and 10 mg/L ZnCl2, the reactor performance significantly decreased, most likely due to the inhibition of bacterial growth by thiocyanate or organic contaminants present in the coke-oven wastewater. Use of mixed culture of NDFO bacteria and thiocyanate/organic-degrading denitrifiers should help improve the reactor performance.


Asunto(s)
Reactores Biológicos , Metales Pesados/química , Nitratos/química , Eliminación de Residuos Líquidos/métodos , Betaproteobacteria , Coque , Desnitrificación , Compuestos Ferrosos , Hierro , Nitrógeno , Óxidos de Nitrógeno , Oxidación-Reducción , Aguas Residuales , Zinc
11.
Chemosphere ; 262: 127897, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32791371

RESUMEN

This paper investigates the dynamics between basalt weathering and heavy metal accumulation through a comparative study of 37 small basaltic watersheds within different climate zones in the Yungui (the Pearl River Basin in southwest China), Xuyi (the Huaihe River Basin in east China) and Leiqiong regions (Hainan Island in south China). From a comprehensive sampling regime of stream water, riverbed sediments and bedrock, this study shows that the concentrations of heavy metals in river water are far below the national surface water quality standard and WHO quality standard for drinking water, indicating no significant ecological risk for water body in these basaltic areas. In contrast, the riverbed sediments exhibit varying degrees of heavy metal enrichment in the process of weathering from bedrock to sediments: without enrichment for Cr, Ni, Cu and Zn, but significant enrichment for Cd, As and Pb. Cd exhibits the largest ecological risk of all the heavy metals in the basaltic watersheds especially in the Yungui region, which can be mainly attributed to the high geological background values in this area. Comparative studies of some major basalt watersheds in the world show that temperature, runoff and elevation differences significantly affect the chemical weathering rates and thus the accumulation of heavy metals.


Asunto(s)
Monitoreo del Ambiente , Metales Pesados/química , Contaminantes Químicos del Agua/química , China , Agua Dulce , Sedimentos Geológicos , Geología , Metales Pesados/análisis , Medición de Riesgo , Ríos , Silicatos , Contaminantes Químicos del Agua/análisis , Calidad del Agua , Tiempo (Meteorología)
12.
Food Chem ; 338: 127797, 2021 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-32950864

RESUMEN

As a nutritious and popular seafood among consumers, Sargassum fusiforme is susceptible to the toxic heavy metals because of its strong adsorption properties. In this study, laser-induced breakdown spectroscopy (LIBS) coupled with a simple framework (only remove some noise and low-intensity variables, and then combine with PLS algorithm) was used to establish the detection models to simultaneously and quantitatively analyze the content of heavy metals arsenic (As), chromium (Cd), cadmium (Cr), copper (Cu), mercury (Hg), lead (Pb) and zinc (Zn) in Sargassum fusiforme. As comparisons, three classic variable methods of successive projections algorithm (SPA), uninformative variable elimination (UVE) and variable importance in projection (VIP) were adopted. The final results showed that six of seven heavy metal models from the TV-PLSR model were optimal. These results demonstrate that the TV-PLSR framework combined with LIBS technique is an effective framework for quantitatively analyzing the heavy metals in Sargassum fusiforme.


Asunto(s)
Contaminación de Alimentos/análisis , Rayos Láser , Metales Pesados/análisis , Sargassum/química , Análisis Espectral , Metales Pesados/química
13.
Carbohydr Polym ; 254: 117324, 2021 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-33357885

RESUMEN

Pectin is natural biopolymer derived from various plant sources and its activity is driven by functional groups. Affinity of pectin and chemical interactions of the active sites to chemicals in media determines fate of adjuvant molecules. Pectin is appropriate co-polymer in modulation of drawbacks of other biopolymers such as low glass transition temperature, low water solubility, and susceptibility to human digestive tract. However, functionality of pectin is improved by its optimized complexation with other chemicals especially in food packaging and tissue engineering. In the last decade, several technical and health-related functions of pectin have been studied through which some products designed and marketed progressively. Pectin-based formulations were commercialized in food, medicine, and radioprotection sectors. It is also advised for alleviation of constipation symptoms. Cost-effectiveness of this multifunctional biopolymer compared to the others that are currently used, has introduced it as a potential alternative for the next years.


Asunto(s)
Estreñimiento/tratamiento farmacológico , Composición de Medicamentos/métodos , Embalaje de Alimentos/métodos , Enfermedades Gastrointestinales/tratamiento farmacológico , Pectinas/uso terapéutico , Protectores contra Radiación/uso terapéutico , Ingeniería de Tejidos/métodos , Absorción Fisicoquímica , Digestión/efectos de los fármacos , Humanos , Metales Pesados/química , Pectinas/química , Protectores contra Radiación/química , Solubilidad , Temperatura de Transición
14.
Food Chem ; 338: 127886, 2021 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-32829294

RESUMEN

Laser-induced breakdown spectroscopy (LIBS) was used to rapidly detect heavy metals in mulberry leaves. For the purpose of increasing detection stability and accuracy, a novel analysis framework consisting of a Kohonen self-organizing map (SOM), a variable selection method using the successive projection algorithm (SPA) and uninformative variable elimination (UVE), and a consensus modeling strategy was proposed for processing LIBS data to determine copper (Cu) and chromium (Cr) content. Results showed that the best regression model for Cu and Cr content achieved the residual predictive deviation (RPD) values of 10.0494 and 8.3874, respectively, and root mean square error of prediction (RMSEP) values of 110.4550 and 41.4561, respectively. The proposed strategy provides a high-accuracy and rapid alternative to the traditional method for monitoring heavy metals in mulberry leaves, which could guarantee the quality of mulberry leaves and potentially be used in food-related industries.


Asunto(s)
Rayos Láser , Metales Pesados/análisis , Morus/química , Espectrofotometría/métodos , Cromo/análisis , Cobre/análisis , Metales Pesados/química , Morus/metabolismo , Hojas de la Planta/química , Hojas de la Planta/metabolismo , Análisis de Componente Principal
15.
Ecotoxicol Environ Saf ; 207: 111275, 2021 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-32920316

RESUMEN

In-situ immobilization is an effective and economically viable strategy for remediation of soil extensively polluted with heavy metals. The long-term sustainability is critical for the remediation practice. In the present study, a ten-year experiment was performed in a Cd-polluted agricultural field to evaluate the long-term stability of lime, silicon fertilizer (SF), fused calcium magnesium phosphate fertilizer (FCMP), bone charcoal, steel slag, and blast furnace slag with one-off application. All amendments had no significant effect on biomass but significantly reduced Cd uptake by Artemisia selengensis at higher dose. Among them, SF and FCMP applied at 1% could reduce Cd uptake by more than 40% to meet the Chinese maximum permissible limit for Cd content in food products (50 µg kg-1). These amendments stimulated high Cd immobilization by increasing the soil pH and decreasing the soil acid-extractable Cd content, which were closely associated with Cd uptake. In addition, the two amendments altered the soil microbial structure and stimulated metabolism pathways, including amino acid, carbohydrate, and lipid metabolism, which are beneficial for soil function and quality. The results proved that SF and FCMP at 1% are stable and ecologically safe amendments, suitable for long-term Cd immobilization, and provide a strategy to mitigate the risk of food product contamination in heavy-metal-polluted soil.


Asunto(s)
Cadmio/análisis , Monitoreo del Ambiente , Contaminantes del Suelo/análisis , Biomasa , Cadmio/metabolismo , Compuestos de Calcio , Carbón Orgánico/química , Contaminación Ambiental , Restauración y Remediación Ambiental , Fertilizantes , Metales Pesados/química , Óxidos , Fosfatos , Suelo/química
16.
Chemosphere ; 262: 128342, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33182112

RESUMEN

Aerobic composting has been used for a long time for bioconversion of manure wastes, however, its application has been limited due to slow transition of organic matters and influence of heavy metals and antibiotics residues. Compost with lime addition can speed up the composting process, while its effects on the evolution of organic matters, heavy metals and antibiotics need to be further investigated. In this research, the effects of lime amendment on organic substances changes was assessed by the spectroscopic characteristics. Besides, chlortetracycline (CTC) removal and Cu, Zn chemical speciation transformation were also evaluated. Results showed that the humic acid-like substances region of fluorescence regional integration (FRI-EEM) increased from 20.5% to 40.9% and 20.6%-32.6%, respectively, in lime addition treatment and control after 15 days of composting, indicating that the addition of lime remarkably improved the transition of organic matter and accelerated the maturity process. Besides, 94.04% of CTC in the manure was removed when lime was added, higher than 86.10% in the control group. The transformation of zinc from exchangeable and reducible into oxidizable and residual fractions was improved while the transformation of copper was affected slightly. Therefore, lime is a suitable amendment material for manure composting, which can accelerate the transition of organic matters due to the regulation of composting pH, as well as eliminate harmful CTC and bioavailable heavy metal, thus promoting the further utilizing of organic substance.


Asunto(s)
Antibacterianos/metabolismo , Compuestos de Calcio , Compostaje/métodos , Estiércol , Metales Pesados/química , Óxidos , Aerobiosis , Animales , Antibacterianos/química , Biodegradación Ambiental , Clortetraciclina/química , Clortetraciclina/metabolismo , Cobre/química , Sustancias Húmicas , Suelo/química , Espectroscopía Infrarroja por Transformada de Fourier , Porcinos , Temperatura , Zinc/química
17.
Phys Chem Chem Phys ; 23(2): 928-943, 2021 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-33355325

RESUMEN

Energy decomposition analysis (EDA) based on absolutely localized molecular orbitals (ALMOs) decomposes the interaction energy between molecules into physically interpretable components like geometry distortion, frozen interactions, polarization, and charge transfer (CT, also sometimes called charge delocalization) interactions. In this work, a numerically exact scheme to decompose the CT interaction energy into pairwise additive terms is introduced for the ALMO-EDA using density functional theory. Unlike perturbative pairwise charge-decomposition analysis, the new approach does not break down for strongly interacting systems, or show significant exchange-correlation functional dependence in the decomposed energy components. Both the energy lowering and the charge flow associated with CT can be decomposed. Complementary occupied-virtual orbital pairs (COVPs) that capture the dominant donor and acceptor CT orbitals are obtained for the new decomposition. It is applied to systems with different types of interactions including DNA base-pairs, borane-ammonia adducts, and transition metal hexacarbonyls. While consistent with most existing understanding of the nature of CT in these systems, the results also reveal some new insights into the origin of trends in donor-acceptor interactions.


Asunto(s)
Aminas/química , Amoníaco/química , Boranos/química , Complejos de Coordinación/química , ADN/química , Emparejamiento Base , Teoría Funcional de la Densidad , Enlace de Hidrógeno , Metales Pesados/química , Modelos Químicos , Electricidad Estática , Elementos de Transición/química
18.
J Ethnopharmacol ; 266: 113457, 2021 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-33039629

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: Trimada is well-known polyherbal Ayurvedic formulation used in Indian Traditional medicine since ancient times. It consisted of three inebriant herbs including "Chitraka" (Plumbago zeylanica Linn. Family- Plumabaginaceae), "Musta" (Cyperus rotundus Linn. Family- Cyperaceae) and Vidanga (Embelia ribes Burm. F. Family- Myrsinaceae) in equal ratios as mentioned in Ayurveda. Trimada is traditionally used to increase the functioning of the digestive system and metabolism. Along with these, it also assists in the reduction of cholesterol as well as reduces stomach aches and chest pain. AIM OF THE STUDY: This study is aimed to identify the metabolites present in this polyherbal formulation. Further, the cytotoxicity and interaction potential of the formulation and individual herbs with Cytochrome P450 isozymes (CYP3A4, 2D6, 2C9, 1A2) was evaluated by MTT assay and CYP450 enzyme inhibition. The concentration of heavy metals was also determined. MATERIAL AND METHODS: Ultra-performance liquid chromatography-quadrupole/time-of-flight mass spectrometry (UPLC-QTOF-MS) analysis was performed to detect and identify the phytoconstituents in the formulation. Cytotoxicity of the formulation was evaluated by MTT assay. CYP450 enzyme interaction potential of the individual herbs and the Trimada formulation was carried out through CYP-CO assay and fluorometric high throughput screening (HTS) assay for individual isozymes. The content of heavy metal in the formulation was quantified by Atomic Absorption Spectroscopy. RESULTS: Trimada formulation exhibited lower cytotoxicity to human liver carcinoma cell line (HepG2). CYP-CO assay revealed that the interaction potential of individual herbs and Trimada on the liver microsomes was found to be lesser than the standard inhibitor ketoconazole. Individual herbs and Trimada formulation displayed higher IC50 values than the respective standard inhibitors in the fluorimetric assay. UPLC-QTOF-MS analysis showed the presence of a number of active phytoconstituents including sesquiterpenes, phenolic acids, benzoquinones, triterpenes and flavonoids. The heavy metal concentration in the traditional medicinal herbal formulation was found within the approved limit. CONCLUSIONS: This study suggested that the individual herbs and Trimada formulation exhibited low cytotoxicity and contributes insignificant interaction with CYP450 isozymes. So, the formulation is considered to be safe for its therapeutic management without any potential drug interaction involving CYP 450 isozymes.


Asunto(s)
Sistema Enzimático del Citocromo P-450/efectos de los fármacos , Medicina Ayurvédica , Microsomas Hepáticos/efectos de los fármacos , Extractos Vegetales/farmacología , Cromatografía Líquida de Alta Presión , Cyperus/química , Sistema Enzimático del Citocromo P-450/metabolismo , Embelia/química , Células Hep G2 , Ensayos Analíticos de Alto Rendimiento , Humanos , Concentración 50 Inhibidora , Isoenzimas , Metales Pesados/análisis , Metales Pesados/química , Metales Pesados/aislamiento & purificación , Microsomas Hepáticos/metabolismo , Extractos Vegetales/química , Extractos Vegetales/metabolismo , Plumbaginaceae/química
19.
J Am Chem Soc ; 142(52): 21640-21644, 2020 12 30.
Artículo en Inglés | MEDLINE | ID: mdl-33337857

RESUMEN

A 5-carboxyuracil (caU) nucleobase was found to pair not only with A (caU-A) by hydrogen bonding but also with other DNA nucleobases by metal coordination bonding. Metal-dependent formation of caU-CuII-caU, caU-HgII-T, caU-AgI-C, and caU-CuII-G pairs was demonstrated by duplex melting analysis and mass spectrometry. The duplexes containing caU-X (X = caU, T, C, and G) were significantly stabilized in the presence of the corresponding metal ions, while the DNA duplexes containing the caU-A pairs were destabilized by the addition of CuII. These results suggest that the hybridization partner of caU-containing DNA strands can be altered by metal complexation. As a result, this study provides a new direction to integrate caU nucleobases to construct diverse metallo-DNA supramolecules and metal-responsive DNA devices.


Asunto(s)
Emparejamiento Base , ADN/química , Metales Pesados/química , Uracilo/química , Enlace de Hidrógeno , Modelos Moleculares , Hibridación de Ácido Nucleico
20.
PLoS One ; 15(10): e0239412, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33091005

RESUMEN

Incineration has emerged as one of the acceptable ways to treat municipal solid waste (MSW) due to its potential in reducing the mass and volume of the waste. However, it produces two major by-product residues, namely MSW-bottom ash (MSW-BA) and MSW-fly ash (MSW-FA). These residues have gained great attention to their hazardous nature and potential to be reused and recycled. In this paper, the physicochemical characterizations of the MSW-BA and the MSW-FA were performed, followed by a systematic investigation of metals extraction from MSW-BA and MSW-FA. Various extracting agents were used to investigate the possibility to extract 21 metals including cadmium (Cd), vanadium (V), chromium (Cr), and lead (Pb). It was revealed that some metals were present in a high amount in the MSW-BA while other metals were higher in the MSW-FA. Moreover, the energy-dispersive X-ray spectroscopy results revealed that the MSW-BA was dominated by oxygen (O) 55.4 ±0.6 wt%, silicon (Si) 22.5 ±0.3 wt%, and calcium (Ca) 18.5 ±0.2 wt%. On the other hand, the MSW-FA was enriched with Ca 45.2 ±0.5 wt%, and O 40.3 ±0.4 wt%. From the scanning electron microscopy, the MSW-BA was observed as flaky with an irregular surface that consisted of large pores, while, the MSW-FA was present as agglomerated particles and had a bimodal distribution. Moreover, Fourier transform infrared spectroscopy revealed that Al-Fe-OH, Al-Al-OH, Si-O, C-O, and C-H were some of the major functional groups present in the ashes. The F-tests concluded that the metal extraction from the MSW-BA and MSW-FA were significantly affected by the acid type. it is concluded that nitric acid and phosphoric acid were the best-suited acid for the MSW-BA while sulfuric acid and phosphoric acid for the MSW-FA. More than 11 wt% of Cd and 9 wt% of Cu were extracted from MSW-BA while 6 wt% of Pb and 4.5 wt% of V were extracted from the MSW-FA. The present methodology is an interesting development in metal extraction from the MSW-BA and the MSW-FA, which can develop in a cost-effective and sustainable option to utilize MSW.


Asunto(s)
Fenómenos Químicos , Ciudades , Ceniza del Carbón/química , Metales Pesados/química , Metales Pesados/aislamiento & purificación , Residuos Sólidos/análisis , Incineración , Reciclaje
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