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1.
Small ; 18(34): e2202648, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35900063

RESUMEN

The enhanced safety, superior energy, and power density of rechargeable metal-air batteries make them ideal energy storage systems for application in energy grids and electric vehicles. However, the absence of a cost-effective and stable bifunctional catalyst that can replace expensive platinum (Pt)-based catalyst to promote oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) at the air cathode hinders their broader adaptation. Here, it is demonstrated that Tin (Sn) doped ß-gallium oxide (ß-Ga2 O3 ) in the bulk form can efficiently catalyze ORR and OER and, hence, be applied as the cathode in Zn-air batteries. The Sn-doped ß-Ga2 O3 sample with 15% Sn (Snx =0.15 -Ga2 O3 ) displayed exceptional catalytic activity for a bulk, non-noble metal-based catalyst. When used as a cathode, the excellent electrocatalytic bifunctional activity of Snx =0.15 -Ga2 O3 leads to a prototype Zn-air battery with a high-power density of 138 mW cm-2 and improved cycling stability compared to devices with benchmark Pt-based cathode. The combined experimental and theoretical exploration revealed that the Lewis acid sites in ß-Ga2 O3 aid in regulating the electron density distribution on the Sn-doped sites, optimize the adsorption energies of reaction intermediates, and facilitate the formation of critical reaction intermediate (O*), leading to enhanced electrocatalytic activity.

2.
Environ Sci Technol ; 55(20): 13504-13512, 2021 10 19.
Artículo en Inglés | MEDLINE | ID: mdl-33555877

RESUMEN

In this study, spinach plants exposed to fresh/unweathered (UW) or weathered (W) copper compounds in soil were analyzed for growth and nutritional composition. Plants were exposed for 45 days to freshly prepared or soil-aged (35 days) nanoparticulate CuO (nCuO), bulk-scale CuO (bCuO), or CuSO4 at 0 (control), 400, 400, and 40 mg/kg of soil, respectively. Foliar health, gas exchange, pigment content (chlorophyll and carotenoid), catalase and ascorbate peroxidase enzymes, gene expression, and Cu bioaccumulation were evaluated along with SEM imagery for select samples. Foliar biomass was higher in UW control (84%) and in UW ionic treatment (87%), compared to the corresponding W treatments (p ≤ 0.1). Root catalase activity was increased by 110% in UW bCuO treatment as compared to the W counterpart; the value for the W ionic treatment was increased by 2167% compared to the UW counterpart (p ≤ 0.05). At 20 days post-transplantation, W nCuO-exposed plants had ∼56% lower carotenoid content compared to both W control and the UW counterpart (p ≤ 0.05). The findings indicate that over the full life cycle of spinach plant the weathering process significantly deteriorates leaf pigment production under CuO exposure in particular and foliar health in general.


Asunto(s)
Nanopartículas del Metal , Nanopartículas , Cobre/análisis , Suelo , Spinacia oleracea
3.
Environ Sci Technol ; 54(9): 5598-5607, 2020 05 05.
Artículo en Inglés | MEDLINE | ID: mdl-32243750

RESUMEN

Cobalt sulfide precipitates, key phases in the natural biogeochemistry of cobalt and in relevant remediation and resource recovery processes, are poorly defined under low-temperature aqueous conditions. Here, we systematically studied Co (Fe) sulfides precipitated and aged in environmentally relevant solutions, defined by different combinations of pH, initial cobalt to iron ratios ([Co]aq/[Fe]aq), with/without S0, and the presence/absence of sulfate-reducing bacteria. The initial abiogenic precipitates were composed exclusively of amorphous Co sulfide nanoparticles (CoS·xH2O) that were stable in anoxic solution for 2 months, with estimated log K* values 1-5 orders of magnitude higher than that previously reported for Co sulfides. The addition of S0, in combination with acidic pH and elevated temperature (60 °C), resulted in recrystallization of the amorphous precipitates into nanocrystalline jaipurite (hexagonal CoS) within 1 month. In the presence of Fe(II)aq, the abiogenic precipitates were composed of more crystalline Co sulfides and/or Co-rich mackinawite, the exact phase being dependent on the [Co]aq/[Fe]aq value. The biogenic precipitates displayed higher crystallinity for Co sulfides (up to the formation of nanocrystalline cobalt pentlandite, Co9S8) and lower crystallinity for Co-rich mackinawite, suggestive of mineral-specific bacterial interaction. The revealed precipitation and transformation pathways of Co (Fe) sulfides in this study allows for a better constraint of Co biogeochemistry in various natural and engineered environments.


Asunto(s)
Cobalto , Nanopartículas , Sulfuros , Temperatura
4.
Ecotoxicol Environ Saf ; 206: 111197, 2020 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-32882572

RESUMEN

In the present study, Zea mays seedlings grown under nano Cu(OH)2 (nCu), bulk Cu(OH)2 (bCu), and ionic CuSO4 (iCu) compound exposure were harvested after six days. The nutritional profile was determined to be significantly disrupted in the roots by 1000 ppm bCu treatment, resulting in a 58.7% reduction in potassium compared to the control. In the shoots, a significant decrease of manganese was observed for 10 and 1000 ppm iCu treatments with 55.7% and 64.2% reductions, respectively. The overall protein content and catalase (CAT) enzymatic activity, however, remained unaffected in either roots or shoots, while an absence of polyphenol oxidase (PPO) activity was observed for all samples. The genetic expression of defense-related genes, metallothionein (MT), CAT, ascorbate peroxidase (APX), and PPO was assessed. The genetic expression of MT was upregulated 50-fold in roots treated with 1000 ppm bCu. There were no significant differences in CAT transcripts among the various treatments, while APX was upregulated 28 and 19-fold in shoots treated with 10 ppm bCu and 10 ppm nCu, respectively. Meanwhile, APX mRNA levels were downregulated five-fold in shoots treated with 1000 ppm iCu. Thus, indicating that the role of APX in plant defense was reinforced in seedlings exposed to low concentration of particulate Cu compounds. Remarkably, no PPO expression was found in any of the treatments and controls, which suggests this enzyme is expressed only under specific external factors or seedlings have an "immature" cascade signaling activation of the PPO system. Taken together, these results show that bCu and nCu treatments at a low concentration do not compromise vital cell machinery but rather elicit the enhancement of defense responses as observed through the increase in APX expression. Furthermore, under optimal concentrations, these Cu treatments show promise in enhancing corn defense responses, which can ultimately lead to increases in future global crop yields.


Asunto(s)
Antioxidantes/metabolismo , Ascorbato Peroxidasas/genética , Cobre/toxicidad , Contaminantes del Suelo/toxicidad , Zea mays/efectos de los fármacos , Ascorbato Peroxidasas/metabolismo , Cobre/química , Relación Dosis-Respuesta a Droga , Iones , Manganeso/metabolismo , Oxidación-Reducción , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/crecimiento & desarrollo , Potasio/metabolismo , Plantones/efectos de los fármacos , Plantones/crecimiento & desarrollo , Contaminantes del Suelo/química , Zea mays/genética , Zea mays/crecimiento & desarrollo , Zea mays/metabolismo
5.
Environ Sci Technol ; 50(13): 6782-92, 2016 07 05.
Artículo en Inglés | MEDLINE | ID: mdl-26690677

RESUMEN

Mass-flow modeling of engineered nanomaterials (ENMs) indicates that a major fraction of released particles partition into soils and sediments. This has aggravated the risk of contaminating agricultural fields, potentially threatening associated food webs. To assess possible ENM trophic transfer, cerium accumulation from cerium oxide nanoparticles (nano-CeO2) and their bulk equivalent (bulk-CeO2) was investigated in producers and consumers from a terrestrial food chain. Kidney bean plants (Phaseolus vulgaris var. red hawk) grown in soil contaminated with 1000-2000 mg/kg nano-CeO2 or 1000 mg/kg bulk-CeO2 were presented to Mexican bean beetles (Epilachna varivestis), which were then consumed by spined soldier bugs (Podisus maculiventris). Cerium accumulation in plant and insects was independent of particle size. After 36 days of exposure to 1000 mg/kg nano- and bulk-CeO2, roots accumulated 26 and 19 µg/g Ce, respectively, and translocated 1.02 and 1.3 µg/g Ce, respectively, to shoots. The beetle larvae feeding on nano-CeO2 exposed leaves accumulated low levels of Ce since ∼98% of Ce was excreted in contrast to bulk-CeO2. However, in nano-CeO2 exposed adults, Ce in tissues was higher than Ce excreted. Additionally, Ce content in tissues was biomagnified by a factor of 5.3 from the plants to adult beetles and further to bugs.


Asunto(s)
Cerio , Tamaño de la Partícula , Cadena Alimentaria , Raíces de Plantas , Suelo
6.
Environ Sci Technol ; 49(5): 2921-8, 2015 Mar 03.
Artículo en Inglés | MEDLINE | ID: mdl-25648544

RESUMEN

Information about changes in physiological and agronomic parameters through the life cycle of plants exposed to engineered nanoparticles (NPs) is scarce. In this study, corn (Zea mays) plants were cultivated to full maturity in soil amended with either nCeO2 or nZnO at 0, 400, and 800 mg/kg. Gas exchange was monitored every 10 days, and at harvest, bioaccumulation of Ce and Zn in tissues was determined by ICP-OES/MS. The effects of NPs exposure on nutrient concentration and distribution in ears were also evaluated by ICP-OES and µ-XRF. Results showed that nCeO2 at both concentrations did not impact gas exchange in leaves at any growth stage, while nZnO at 800 mg/kg reduced net photosynthesis by 12%, stomatal conductance by 15%, and relative chlorophyll content by 10% at day 20. Yield was reduced by 38% with nCeO2 and by 49% with nZnO. Importantly, µ-XRF mapping showed that nCeO2 changed the allocation of calcium in kernels, compared to controls. In nCeO2 treated plants, Cu, K, Mn, and Zn were mainly localized at the insertion of kernels into cobs, but Ca and Fe were distributed in other parts of the kernels. Results showed that nCeO2 and nZnO reduced corn yield and altered quality of corn.


Asunto(s)
Cerio/análisis , Estadios del Ciclo de Vida/efectos de los fármacos , Nanopartículas , Semillas/efectos de los fármacos , Zea mays/efectos de los fármacos , Óxido de Zinc/análisis , Animales , Imagen Óptica/métodos
7.
Proc Natl Acad Sci U S A ; 109(37): E2451-6, 2012 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-22908279

RESUMEN

Based on previously published hydroponic plant, planktonic bacterial, and soil microbial community research, manufactured nanomaterial (MNM) environmental buildup could profoundly alter soil-based food crop quality and yield. However, thus far, no single study has at once examined the full implications, as no studies have involved growing plants to full maturity in MNM-contaminated field soil. We have done so for soybean, a major global commodity crop, using farm soil amended with two high-production metal oxide MNMs (nano-CeO(2) and -ZnO). The results provide a clear, but unfortunate, view of what could arise over the long term: (i) for nano-ZnO, component metal was taken up and distributed throughout edible plant tissues; (ii) for nano-CeO(2), plant growth and yield diminished, but also (iii) nitrogen fixation--a major ecosystem service of leguminous crops--was shut down at high nano-CeO(2) concentration. Juxtaposed against widespread land application of wastewater treatment biosolids to food crops, these findings forewarn of agriculturally associated human and environmental risks from the accelerating use of MNMs.


Asunto(s)
Calidad de los Alimentos , Glycine max/efectos de los fármacos , Nanoestructuras/toxicidad , Fijación del Nitrógeno/efectos de los fármacos , Contaminantes del Suelo/toxicidad , Agricultura , Cerio , Cromatografía de Gases , Fertilidad , Espectrometría de Masas , Microscopía Electrónica , Nanotecnología/tendencias , Contaminantes del Suelo/farmacocinética , Glycine max/crecimiento & desarrollo , Espectroscopía de Absorción de Rayos X , Óxido de Zinc
8.
Environ Sci Technol ; 46(14): 7637-43, 2012 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-22715806

RESUMEN

Advances in nanotechnology have raised concerns about possible effects of engineered nanomaterials (ENMs) in the environment, especially in terrestrial plants. In this research, the impacts of TiO(2) nanoparticles (NPs) were evaluated in hydroponically grown cucumber (Cucumis sativus) plants. Seven day old seedlings were treated with TiO(2) NPs at concentrations varying from 0 to 4000 mg L(-1). At harvest, the size of roots and shoots were measured. In addition, micro X- ray fluorescence (micro-XRF) and micro X-ray absorption spectroscopy (micro-XAS), respectively, were used to track the presence and chemical speciation of Ti within plant tissues. Results showed that at all concentrations, TiO(2) significantly increased root length (average >300%). By using micro-XRF it was found that Ti was transported from the roots to the leaf trichomes, suggesting that trichomes are possible sink or excretory system for the Ti. The micro-XANES spectra showed that the absorbed Ti was present as TiO(2) within the cucumber tissues, demonstrating that the TiO(2) NPs were not biotransformed.


Asunto(s)
Cucumis sativus/metabolismo , Nanopartículas/química , Espectrometría por Rayos X , Sincrotrones , Titanio/metabolismo , Espectroscopía de Absorción de Rayos X , Transporte Biológico/efectos de los fármacos , Cucumis sativus/efectos de los fármacos , Cucumis sativus/crecimiento & desarrollo , Hidroponía , Nanopartículas/toxicidad , Nitrógeno/metabolismo , Hojas de la Planta/citología , Hojas de la Planta/efectos de los fármacos , Hojas de la Planta/metabolismo , Raíces de Plantas/anatomía & histología , Raíces de Plantas/citología , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/metabolismo , Brotes de la Planta/anatomía & histología , Brotes de la Planta/efectos de los fármacos , Brotes de la Planta/metabolismo , Reproducibilidad de los Resultados , Titanio/toxicidad
9.
Nanomaterials (Basel) ; 12(14)2022 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-35889574

RESUMEN

Carbohydrates and phytonutrients play important roles in tomato fruit's nutritional quality. In the current study, Fe3O4, MnFe2O4, ZnFe2O4, Zn0.5Mn0.5Fe2O4, Mn3O4, and ZnO nanomaterials (NMs) were synthesized, characterized, and applied at 250 mg/L to tomato plants via foliar application to investigate their effects on the nutritional quality of tomato fruits. The plant growth cycle was conducted for a total of 135 days in a greenhouse and the tomato fruits were harvested as they ripened. The lycopene content was initially reduced at 0 stored days by MnFe2O4, ZnFe2O4, and Zn0.5Mn0.5Fe2O4; however, after a 15-day storage, there was no statistical difference between the treatments and the control. Moreover, the ß-carotene content was also reduced by Zn0.5Mn0.5Fe2O4, Mn3O4, and ZnO. The effects of the Mn3O4 and ZnO carried over and inhibited the ß-carotene after the fruit was stored. However, the total phenolic compounds were increased by ZnFe2O4, Zn0.5Mn0.5Fe2O4, and ZnO after 15 days of storage. Additionally, the sugar content in the fruit was enhanced by 118% and 111% when plants were exposed to Mn3O4 and ZnO, respectively. This study demonstrates both beneficial and detrimental effects of various NMs on tomato fruit quality and highlights the need for caution in such nanoscale applications during crop growth.

10.
Sci Total Environ ; 844: 157160, 2022 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-35798116

RESUMEN

The objective of the current study is to evaluate both the positive and negative effects of manganese-doped graphene quantum dots (GQD-Mn) on Capsicum annuum L. grown under salt stress. GQD-Mn was synthesized, characterized, and foliar-applied (250 mg/L, 120 mg/L, 60 mg/L) to C. annuum L. before and after the flowering stage, during which 100 mM of NaCl solution was introduced into the soil as salt stress. Controls were designed as absolute control (no nanomaterials or salt) and negative control (no nanomaterials only salt). Herein, we report that GQD-Mn offset the reduction of fruit production in salt-stressed C. annuum L. by around 40 %. However, based on a comprehensive analysis of normal alkanes (n-alkane) using gas chromatography-mass spectrometry (GC-MS), we also observed that the leaf epicuticular wax profile was disturbed by GQD-Mn, as the concentration of long-chain n-alkanes was increased. Meanwhile, the content of magnesium (Mg) and zinc (Zn) indicated a potential promoted photosynthesis activity in C. annuum L leaves. We hypothesize that the optical properties of GQD-Mn allow leaves to utilize light more efficiently, thus improving photosynthetic activities in plants to acclimate salt stress. But the increased light usage also induced heat stress on the leaf surfaces, which caused n-alkanes changes. Our results provided a unique perspective on nano-plant interaction that value both beneficial and toxic effects of nanomaterials, especially when evaluating the safety of nano-enabled agriculture in areas facing harsh environmental conditions such as salinity.


Asunto(s)
Capsicum , Grafito , Puntos Cuánticos , Alcanos , Capsicum/química , Iones , Manganeso/toxicidad , Hojas de la Planta , Puntos Cuánticos/toxicidad , Estrés Salino
11.
Sci Rep ; 12(1): 19010, 2022 Nov 08.
Artículo en Inglés | MEDLINE | ID: mdl-36347903

RESUMEN

Additive manufacturing, also called 3D printing, has the potential to enable the development of flexible, wearable and customizable batteries of any shape, maximizing energy storage while also reducing dead-weight and volume. In this work, for the first time, three-dimensional complex electrode structures of high-energy density LiNi1/3Mn1/3Co1/3O2 (NMC 111) material are developed by means of a vat photopolymerization (VPP) process combined with an innovative precursor approach. This innovative approach involves the solubilization of metal precursor salts into a UV-photopolymerizable resin, so that detrimental light scattering and increased viscosity are minimized, followed by the in-situ synthesis of NMC 111 during thermal post-processing of the printed item. The absence of solid particles within the initial resin allows the production of smaller printed features that are crucial for 3D battery design. The formulation of the UV-photopolymerizable composite resin and 3D printing of complex structures, followed by an optimization of the thermal post-processing yielding NMC 111 is thoroughly described in this study. Based on these results, this work addresses one of the key aspects for 3D printed batteries via a precursor approach: the need for a compromise between electrochemical and mechanical performance in order to obtain fully functional 3D printed electrodes. In addition, it discusses the gaps that limit the multi-material 3D printing of batteries via the VPP process.

12.
Sci Total Environ ; 774: 145699, 2021 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-33609834

RESUMEN

Rutile titanium dioxide nanoparticles (nTiO2) were weathered in field soil at 0, 100, 200, and 400 mg Ti/kg soil for four months. Two types of nTiO2 with different surface coatings (hydrophilic and hydrophobic), uncoated nTiO2 (pristine), and the untreated control were included. Thereafter, carrot seeds (Daucus carota L.) were sown in those soils and grown in a growth chamber for 115 days until full maturity. A comparison was made between this and our previous unaged study, where carrots were treated in the same way in soil with freshly amended nTiO2. The responses of plants depended on the nTiO2 surface coating and concentration. The aged hydrophobic and hydrophilic-coated nTiO2 induced more positive effects on plant development at 400 and 100 mg Ti/kg soil, respectively, compared with control and pristine treatments. Taproot and leaf fresh biomass and plant height were improved by up to 64%, 40%, and 40% compared with control, respectively. Meanwhile, nutrient elements such as Fe in leaves, Mg in taproots, and Ca, Zn, and K in roots were enhanced by up to 66%, 64%, 41, 143% and 46%, respectively. However, the contents of sugar, starch, and some other metal elements in taproots were negatively affected, which may compromise their nutritional quality. Taken together, the overall growth of carrots was benefited by the aged nTiO2 depending on coating and concentration. The aging process served as a potential sustainable strategy to alleviate the phytotoxicity of unweathered nanoparticles.


Asunto(s)
Daucus carota , Nanopartículas , Nanopartículas/toxicidad , Nutrientes , Suelo , Titanio/análisis , Titanio/toxicidad
13.
J Hazard Mater ; 402: 123768, 2021 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-33254779

RESUMEN

The production and environmental release of surface-modified titanium dioxide nanoparticles (nTiO2) have increased. Hence, crops may be directly exposed to the nTiO2 in soil. In this study, we grew carrots in soils amended with pristine, hydrophilic and hydrophobic surface-coated nTiO2 at 100, 200, and 400 mg kg-1 until full-plant maturity. The content of Ti in plant secondary roots treated with different nTiO2 at 400 mg kg-1 was in the order of hydrophobic > hydrophilic > pristine treatments, with values of 140.1, 100.5, and 64.3 mg kg-1, respectively. The fresh biomass of the taproot was significantly decreased by all nTiO2 forms at 400 mg kg-1 by up to 56 %, compared to control. Pristine nTiO2 at 100 mg kg-1 enhanced the fresh weight of leaves by 51 % with respect to control. Remarkably, an abnormal increase of taproot splitting was found in plants treated with all nTiO2 forms. In carrots treated with the surface-coated nTiO2, the accumulation of Ca, Mg, Fe, and Zn increased in leaves; but Mg, Mn, and Zn decreased in taproots. These results suggest that future regulation of nTiO2 release into soils should consider its surface coating properties since the phytotoxicity effects depend on nTiO2 outer structure.


Asunto(s)
Daucus carota , Nanopartículas , Interacciones Hidrofóbicas e Hidrofílicas , Suelo , Titanio/análisis , Titanio/toxicidad
14.
Environ Sci Technol ; 44(19): 7315-20, 2010 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-20384348

RESUMEN

Concern and interest related to the effects of nanomaterials on living organisms are growing in both the scientific and public communities. Reports have described the toxicity of nanoparticles (NPs) on micro- and macro-organisms, including some plant species. Nevertheless, to the authors' knowledge there are no reports on the biotransformation of NPs by edible terrestrial plants. Here, shown for the first time, is evidence pertaining to the biotransformation of ZnO and CeO(2) NPs in plant seedlings. Although the NPs did not affect soybean germination, they produced a differential effect on plant growth and element uptake. By using synchrotron X-ray absorption spectroscopy we obtained clear evidence of the presence of CeO(2) NPs in roots, whereas ZnO NPs were not present. Random amplified polymorphic DNA assay was applied to detect DNA damage and mutations caused by NPs. Results obtained from the exposure of soybean plants to CeO(2) NPs show the appearance of four new bands at 2000 mg L(-1) and three new bands at 4000 mg L(-1) treatment. In this study we demonstrated genotoxic effects from the exposure of soybean plants to CeO(2) NPs.


Asunto(s)
Cerio/toxicidad , Glycine max/efectos de los fármacos , Mutágenos/toxicidad , Óxido de Zinc/toxicidad , Secuencia de Bases , Biomasa , Biotransformación , Cerio/farmacocinética , Cartilla de ADN , ADN de Plantas/aislamiento & purificación , Raíces de Plantas/crecimiento & desarrollo , Reacción en Cadena de la Polimerasa , Técnica del ADN Polimorfo Amplificado Aleatorio , Glycine max/genética , Glycine max/crecimiento & desarrollo , Óxido de Zinc/farmacocinética
15.
Sci Total Environ ; 725: 138387, 2020 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-32298898

RESUMEN

With the exponential growth of nanomaterial production in the last years, nano copper (Cu)-based compounds are gaining more consideration in agriculture since they can work as pesticides or fertilizers. Chinese scallions (Allium fistulosum), which are characterized by their high content of the antioxidant allicin, were the chosen plants for this study. Spectroscopic and microscopic techniques were used to evaluate the nutrient element, allicin content, and enzyme antioxidant properties of scallion plants. Plants were harvested after growing for 80 days at greenhouse conditions in soil amended with CuO particles [nano (nCuO) and bulk (bCuO)] and CuSO4 at 75-600 mg/kg]. Two-photon microscopy images demonstrated the particulate Cu uptake in nCuO and bCuO treated roots. In plants exposed to 150 mg/kg of the Cu-based compounds, root Cu content was higher in plants treated with nCuO compared with bCuO, CuSO4, and control (p ≤ 0.05). At 150 mg/kg, nCuO increased root Ca (86%), root Fe (71%), bulb Ca (74%), and bulb Mg (108%) content, compared with control (p ≤ 0.05). At the same concentration, bCuO reduced root Ca (67%) and root Mg (33%), compared with control (p ≤ 0.05). At all concentrations, nCuO and CuSO4 increased leaf allicin (56-187% and 42-90%, respectively), compared with control (p ≤ 0.05). The antioxidant enzymes were differentially affected by the Cu-based treatments. Overall, the data showed that nCuO enhances nutrient and allicin contents in scallion, which suggests they might be used as a nanofertilizer for onion production.


Asunto(s)
Allium , Nanopartículas del Metal , Nanopartículas , Cobre , Disulfuros , Nutrientes , Cebollas , Raíces de Plantas , Ácidos Sulfínicos
16.
J Agric Food Chem ; 68(7): 1986-1997, 2020 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-31986044

RESUMEN

In this study, the impact of cerium oxide nanoparticles on the nutritional value of tomato (Solanum lycopersicum) fruit grown in soil infested with Fusarium oxysporum f. sp. lycopersici was investigated in a greenhouse pot study. Three-week old seedlings of Bonny Best tomato plants were exposed by foliar and soil routes to nanoparticle CeO2 (NP CeO2) and cerium acetate (CeAc) at 0, 50, and 250 mg/L and transplanted into pots containing a soil mixture infested with the Fusarium wilt pathogen. Fruit biomass, water content, diameter, and nutritional content (lycopene, reducing and total sugar) along with elemental composition, including Ce, were evaluated. Fruit Ce concentration was below the detection limit in all treatments. Foliar exposure to NP CeO2 at 250 increased the fruit dry weight (67%) and lycopene content (9%) in infested plants, compared with the infested untreated control. Foliar exposure to CeAc at 50 mg/L reduced fruit fresh weight (46%) and water content (46%) and increased the fruit lycopene content by 11% via root exposure as compared with the untreated infested control. At 250 mg/L, CeAc increased fruit dry weight (94%), compared with the infested untreated control. Total sugar content decreased in fruits of infested plants exposed via roots to NP CeO2 at 50 mg/kg (63%) and 250 mg/kg (54%), CeAc at 50 mg/kg (46%), and foliarly at 50 mg/L (50%) and 250 mg/L (50%), all compared with the infested untreated control. Plants grown in Fusarium-infested soil had decreased fruit dry weight (42%) and lycopene content (17%) and increased total sugar (60%) and Ca content (140%), when compared with the noninfested untreated control (p ≤ 0.05). Overall, the data suggested minimal negative effects of NP CeO2 on the nutritional value of tomato fruit while simultaneously suppressing Fusarium wilt disease.


Asunto(s)
Cerio/farmacología , Frutas/química , Fungicidas Industriales/farmacología , Fusarium/fisiología , Enfermedades de las Plantas/microbiología , Solanum lycopersicum/microbiología , Frutas/efectos de los fármacos , Frutas/crecimiento & desarrollo , Frutas/microbiología , Fusarium/efectos de los fármacos , Solanum lycopersicum/química , Solanum lycopersicum/efectos de los fármacos , Solanum lycopersicum/crecimiento & desarrollo , Nanopartículas/química , Valor Nutritivo , Suelo/química , Microbiología del Suelo
17.
Sci Total Environ ; 742: 140572, 2020 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-32623177

RESUMEN

The recent application of nano copper (Cu) compounds in the agrosystem has shown potential to improve the physiological performance and agronomical parameters of crops. We grew alfalfa (Medicago sativa) in potting mix amended with bulk, nano, and ionic Cu compounds at 80 and 280 mg Cu/kg; then, we evaluated plant performance at physiological and molecular levels. Plants treated with bulk/nano Cu presented better agronomical responses. The P and S content was reduced in bulk and ionic Cu-exposed plants, compared to controls (p ≤ .05). All Cu forms increased the content of Fe and Zn in roots and Fe in leaves, compared to controls (p ≤ .05). Leaf-superoxide dismutase expression was augmented ~27-fold and rubisco mRNA was unaffected in bulk/nano Cu-treated plants, compared to controls (p ≤ .05). Bulk/nano Cu incremented the relative abundance of microorganisms involved in the elemental uptake. These results indicate that nano Cu improved the physiology of alfalfa and can be considered as potential nanofertilizers.


Asunto(s)
Nanopartículas del Metal , Nanocables , Cobre , Genómica , Medicago sativa , Raíces de Plantas
18.
Sci Total Environ ; 665: 100-106, 2019 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-30772537

RESUMEN

Numerous studies on short term effects of copper-based nanomaterials on plants have been published, however investigations with plants grown in a complex soil medium are lacking. In this study Grey Zucchini (Cucurbita pepo) was grown in an environmental growth chamber using a 1:1 (v/v) potting mix native soil mixture amended with Kocide 3000, nCuO, bCuO, or Cu NPs. After 3 weeks Cu concentrations in the root, stem, and leaves of treated plants were significantly higher than control plants. This increase in Cu concentration did not adversely affect plant growth or chlorophyll production. The activity ascorbate peroxidase (APX) in the roots tissues of plants treated with Kocide 3000, nCuO, and bCuO decreased by at least 45%. Catalase (CAT) activity in root tissues of plants treated with 50 mg/kg of Cu NP decreased by 77%, while those treated at 200 mg/kg were reduced by 80%, compared to controls. The activity of APX and CAT in the leaves of all treated plants remained similar to control plants. Based on the endpoints used in this study, with the exception of a decrease in the accumulation of Zn and B in the roots, the exposure of zucchini to the tested copper compounds resulted in no negative effects.


Asunto(s)
Cobre/toxicidad , Cucurbita/fisiología , Nanopartículas del Metal/toxicidad , Contaminantes del Suelo/toxicidad , Cobre/metabolismo , Cucurbita/efectos de los fármacos , Nanopartículas del Metal/análisis , Contaminantes del Suelo/metabolismo
19.
Environ Int ; 123: 558-566, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30622080

RESUMEN

The Paso del Norte region is characterized by its dynamic industries and active agriculture. Throughout the years, urban and agricultural soils from this region have been exposed to xenobiotics, heavy metals, and excess of hydrocarbons. In this study, samples of urban [domestic workshops (DW)] and agricultural-intended (AI) soils from different sites of Ciudad Juárez, Mexico were evaluated for their fertility, element content, and microbial diversity. Chemical analyses showed that nitrites, nitrates, P, K, Mg, and Mn were predominantly higher in AI soils, compared to DW soils (p ≤ 0.05). The composition of soil microbial communities showed that Proteobacteria phylum was the most abundant in both soils (67%, p ≤ 0.05). In AI soils, Paracoccus denitrificans was reduced (p ≤ 0.05), concurring with an increment in nitrates, while the content of nitrogen was negatively correlated with the rhizobium group (r2 = -0.65, p ≤ 0.05). In DW soils, the Firmicutes phylum represented up to ~25%, and the relative abundance of Proteobacteria strongly correlated with a higher Cu content (r2 = 0.99, p ≤ 0.0001). The monotypic genus Sulfuricurvum was found only in oil-contaminated soil samples. Finally, all samples showed the presence of the recently created phylum Candidatus saccharibacteria. These results describe the productivity parameters of AI soils and its correlation to the microbial diversity, which are very important to understand and potentiate the productivity of soils. The data also suggest that soils impacted with hydrocarbons and metal(oid)s allow the reproduction of microorganisms with the potential to alleviate contaminated sites.


Asunto(s)
Microbiota , Microbiología del Suelo , Contaminantes del Suelo/toxicidad , Suelo/química , Agricultura , Bacterias/clasificación , Contaminación Ambiental , Hidrocarburos/toxicidad , Metagenómica , Metales Pesados/toxicidad , México , Nitrógeno/análisis , Análisis Espectral
20.
J Agric Food Chem ; 66(26): 6609-6618, 2018 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-29281882

RESUMEN

The interactions of nanoparticles (NPs) with biochar and soil components may substantially influence NP availability and toxicity to biota. In the present study, earthworms ( Eisenia fetida) were exposed for 28 days to a residential or agricultural soil amended with 0-2000 mg of CeO2 NP/kg and with biochar (produced by the pyrolysis of pecan shells at 350 and 600 °C) at various application rates [0-5% (w/w)]. After 28 days, earthworms were depurated and analyzed for Ce content, moisture content, and lipid peroxidation. The results showed minimal toxicity to the worms; however, biochar (350 or 600 °C) was the dominant factor, accounting for 94 and 84% of the variance for the moisture content and lipid peroxidation, respectively, in the exposed earthworms. For both soils with 1000 mg of CeO2/kg at 600 °C, biochar significantly decreased the accumulation of Ce in the worm tissues. Amendment with 350 °C biochar had mixed responses on Ce uptake. Analysis by micro X-ray fluorescence (µ-XRF) and micro X-ray absorption near edge structure (µ-XANES) was used to evaluate Ce localization, speciation, and persistence in CeO2- and biochar-exposed earthworms after depuration for 12, 48, and 72 h. Earthworms from the 500 mg of CeO2/kg and 0% biochar treatments eliminated most Ce after a 48 h depuration period. However, in the same treatment and with 5% BC-600 (biochar pyrolysis temperature of 600 °C), ingested biochar fragments (∼50 µm) with Ce adsorbed to the surfaces were retained in the gut after 72 h. Additionally, Ce remained in earthworms from the 2000 mg of CeO2/kg and 5% biochar treatments after depuration for 48 h. Analysis by µ-XANES showed that, within the earthworm tissues, Ce remained predominantly as Ce4+O2, with only few regions (2-3 µm2) where it was found in the reduced form (Ce3+). The present findings highlight that soil and biochar properties have a significant influence in the internalization of CeO2 NPs in earthworms; such interactions need to be considered when estimating NP fate and effects in the environment.


Asunto(s)
Cerio/metabolismo , Carbón Orgánico/metabolismo , Oligoquetos/química , Oligoquetos/metabolismo , Contaminantes del Suelo/metabolismo , Animales , Cerio/análisis , Carbón Orgánico/análisis , Nanopartículas del Metal/análisis , Suelo/química , Contaminantes del Suelo/análisis , Espectrometría por Rayos X , Sincrotrones
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