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1.
NanoImpact ; : 100532, 2024 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-39454679

RESUMO

Titanium dioxide nanoparticles (TiO2 NPs) are extensively used in various fields and can consequently be detected in wastewater, making it necessary to study their potential impacts on biological wastewater treatment processes. In this study, the shock-load impacts of TiO2 NPs were investigated at concentrations ranging between 1 and 200 mg L-1 on nutrient removal, extracellular polymeric substances (EPSs), microbial activity in aerobic granular sludge (AGS), and algal-bacterial granular sludge (AB-AGS) bioreactors. The results indicated that low concentration (≤10 mg L-1) TiO2 NPs had no effect on microbial activity or the removal of chemical oxygen demand (COD), nitrogen, and phosphorus, due to the increased production of extracellular polymeric substances (EPSs) in the sludge. In contrast, the performance of both AGS and AB-AGS bioreactors gradually deteriorated as the concentration of TiO2 NPs in the influent increased to 50, 100, and 200 mg L-1. Specifically, the ammonia­nitrogen removal rate in AGS decreased from 99.9 % to 88.6 %, while in AB-AGS it dropped to 91.3 % at 200 mg L-1 TiO2 NPs. Furthermore, the nitrate­nitrogen levels remained stable in AB-AGS, while NO3-N was detected in the effluent of AGS at 100 and 200 mg L-1. Microbial activities change similarly as smaller decrease in the specific ammonia uptake rate (SAUR) and specific nitrate uptake rate (SNUR) was found in AB-AGS compared to those in AGS. Overall, the algal-bacterial sludge exhibited higher resilience against TiO2 NPs, which was attributed to a) higher EPS volume, b) smaller decrease in LB-EPS, and c) the favorable protein to polysaccharide (PN/PS) ratio. This in turn, along with the symbiotic relationship between the algae and bacteria, mitigates the toxic effects of nanoparticles.

2.
J Hazard Mater ; 480: 136234, 2024 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-39461295

RESUMO

Desilication products (DSPs) are one of the main components of bauxite residue, which is currently discharged without further usage. The present study reports on the use of DSPs as adsorbents for basic fuchsine dye. Using artificial spent liquor, we synthesized not only neat DSP but also solids in the presence of various organics, to account for their likely occurrence during the Bayer process. The physico-chemical properties of all DSPs are similar, except for the specific surface area (SSA), which decreases as the organic content in the final product increases. Further, we compared the adsorption characteristics of DSP to those of Y-type faujasite (FAUY). Strikingly, both time-dependent adsorption measurements and adsorption isotherms showed that DSP, despite its 28-fold smaller SSA, binds 4-5 times more dye molecules. Computational modelling for sodalite (as a model for DSP) and FAUY indicates not only more favourable adsorbent-adsorbate interactions, but also more available free Si-OH sites for binding of fuchsine in the case of sodalite. Finally, we find that organic impurities present in the Bayer liquor do not alter the adsorption capacity of neat DSP to any significant degree; therefore, this adsorbent tolerates numerous organic contaminants without decreasing its affinity to the binding of fuchsine.

3.
Nanomaterials (Basel) ; 14(17)2024 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-39269098

RESUMO

Using a co-precipitation technique, the anionic form of sulisobenzone (benzophenone-4) sunscreen ingredient was incorporated into the interlayer space of CaFe-hydrocalumite for the first time. Using detailed post-synthetic millings of the photoprotective nanocomposite obtained, we aimed to study the mechanochemical effects on complex, hybridized layered double hydroxides (LDHs). Various physicochemical properties of the ground and the intact LDHs were compared by powder X-ray diffractometry, N2 adsorption-desorption, UV-Vis diffuse reflectance, infrared and Raman spectroscopy, scanning electron microscopy and thermogravimetric measurements. The data showed significant structural and morphological deformations, surface and textural changes and multifarious thermal behavior. The most interesting development was the change in the optical properties of organic LDHs; the milling significantly improved the UV light blocking ability, especially around 320 nm. Spectroscopic results verified that this could be explained by a modification in interaction between the LDH layers and the sulisobenzone anions, through modulated π-π conjugation and light absorption of benzene rings. In addition to the vibrating mill often used in the laboratory, the photoprotection reinforcement can also be induced by the drum mill grinding system commonly applied in industry.

4.
ACS Appl Mater Interfaces ; 16(40): 54485-54495, 2024 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-39316750

RESUMO

Antioxidant nanozymes are powerful tools to combat oxidative stress, which can be further improved by applying nanozyme mixtures of multiple enzymatic function. Here, cocktails of Prussian blue (PB) nanocubes and copper(II) exchanged ZSM-5 zeolites (CuZ) with enhanced reactive oxygen species (ROS) scavenging activity were developed. Surface functionalization of the particles was performed using polymers to obtain stable colloids, i.e., resistant to aggregation, under a wide range of experimental conditions. The nanozyme cocktails possessed advanced antioxidant properties with multiple enzyme-like functions, catalyzing the decomposition of ROS in cascade reactions. The activity of the mixture far exceeded that of the individual particles, particularly in the peroxidase assay, where an improvement of more than an order of magnitude was observed, pointing to coamplification of the enzymatic activity. In addition, it was revealed that the copper(II) site in the CuZ plays an important role in the decomposition of both superoxide radicals and hydrogen peroxide, as it directly catalyzes the former reaction and acts as cocatalyst in the latter process by boosting the peroxidase activity of the PB nanozyme. The results give important insights into the design of synergistic particle mixtures for the broad-spectrum scavenging of ROS to develop efficient tools for antioxidant treatments in both medical therapies and industrial manufacturing processes.


Assuntos
Antioxidantes , Cobre , Ferrocianetos , Espécies Reativas de Oxigênio , Ferrocianetos/química , Antioxidantes/química , Antioxidantes/farmacologia , Cobre/química , Cobre/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Espécies Reativas de Oxigênio/química , Zeolitas/química , Peróxido de Hidrogênio/química , Catálise , Estresse Oxidativo/efeitos dos fármacos
5.
Chem Commun (Camb) ; 60(76): 10520-10523, 2024 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-39228353

RESUMO

Liquid phase direct amination of phenols to primary anilines with hydrazine was achieved using commercial NiLa-perovskite catalysts as bifunctional Lewis acid/redox-active catalysts without adding any external hydride sources. The amination strategy took place efficiently in the absence of any amount of reducing gasses (H2/NH3) and noble metals under mild conditions.

6.
Heliyon ; 10(18): e37421, 2024 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-39323807

RESUMO

Surface modification, including the anchoring of functional groups is a popular method to increase the photocatalytic activity of semiconductor photocatalysts. These species can trap excited electrons, thus prolonging the life of the charge carriers. N-containing functional groups are suitable for this purpose due to their high electron density. Here, we report a facile synthesis method for preparing interfacial N-based functional groups-modified and nitrogen-doped SrTiO3 photocatalysts. Among the modified samples (with 0.42-11.14 at.% nominal nitrogen content), the one with 7.71 at.% nitrogen showed 6.4 times higher photooxidation efficiency for phenol and 2.2 times better photoreduction efficiency for CO2 conversion than the unmodified SrTiO3 reference. Characterization results showed that using a low amount of nitrogen source resulted in low but measurable nitrogen doping, which did not significantly affect the photocatalytic activity. The formation of surface amine groups was significant even at lower initial nitrogen concentrations, while higher amounts of nitrogen source gradually resulted in the incorporation of nitrogen in higher amounts. Surface amine groups decreased the recombination of charge carriers, resulting in increased photocatalytic activity.

7.
Heliyon ; 10(14): e34938, 2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-39149055

RESUMO

Calcium titanate (CTO) photocatalysts were synthesized using a sol-gel method by adopting a cost-efficient, rapid calcination technique. The CTOs were characterized by X-ray diffractometry, X-ray photoelectron spectroscopy, infrared spectroscopy, nitrogen adsorption, porosimetry measurements, scanning/transmission electron microscopy, and diffuse reflectance spectroscopy. Their photocatalytic activity was assessed through the photocatalytic degradation of phenol, oxalic acid, and chlorophenol under UV light exposure, using a commercial CTO as a reference. The stability of the samples was evaluated using compounds with -OH, -COOH, and -Cl functional groups. Characterization results showed that CTO composites containing anatase, rutile, and brookite titania were obtained. Increasing the calcination temperature led to various crystalline compositions, higher crystallinity, larger primary crystallite sizes, and smaller specific surface areas. The photocatalytic activity of all CTO/TiO2 composites was superior compared to the commercial CTO we used as a reference. The high photocatalytic activity of the best-performing composites was attributed to their higher specific surface areas and the synergistic effect between the crystal phases. A cost comparison was also made between our unique calcination technique and conventional calcination, and it was found that our method is approximately 35% more cost-effective, while retaining the photocatalytic activity.

8.
Plants (Basel) ; 13(14)2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-39065423

RESUMO

Reversible protein phosphorylation regulates various cellular mechanisms in eukaryotes by altering the conformation, activity, localization, and stability of substrate proteins. In Arabidopsis thaliana root meristems, histone post-translational modifications are crucial for proper cell division, and they are also involved in oxidative stress signaling. To investigate the link between reactive oxygen species (ROS) and mitosis, we treated various Arabidopsis genotypes, including wild-types and mutants showing dysfunctional PP2A, with the ROS-inducing herbicide diquat (DQ). Studying the c3c4 double catalytic subunit mutant and fass regulatory subunit mutants of PP2A provided insights into phosphorylation-dependent mitotic processes. DQ treatment reduced mitotic activity in all genotypes and caused early mitotic arrest in PP2A mutants, likely due to oxidative stress-induced damage to essential mitotic processes. DQ had a minimal effect on reversible histone H3 phosphorylation in wild-type plants but significantly decreased phospho-histone H3 levels in PP2A mutants. Following drug treatment, the phosphatase activity decreased only in the stronger phenotype mutant plants (fass-5 and c3c4). Our findings demonstrate that (i) the studied PP2A loss-of-function mutants are more sensitive to increased intracellular ROS and (ii) DQ has indirect altering effects of mitotic activities and histone H3 phosphorylation. All these findings underscore the importance of PP2A in stress responses.

9.
Environ Res ; 260: 119665, 2024 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-39048062

RESUMO

The intensifying production and release into the environment as well as the increasing potential in agricultural applications make the relationship between plants and nickel nanoparticles (Ni NPs) a relevant and timely topic. The aim of this review is to give an overview and discuss the latest findings about the relationship of Ni NPs and plants. Ni NPs can be synthesized using phytochemicals derived from plant parts in an environmentally friendly manner. There are several ways for these nanoparticles to enter plant cells and tissues. This can be demonstrated through various imaging and chemical mapping approaches (e.g., transmission electron microscopy, X-ray fluorescence spectroscopy etc.). NiO NPs affect plants at multiple levels, including subcellular, cellular, tissue, organ, and whole-plant levels. However, the effects of Ni NPs on plants' ecological partners (e.g., rhizobiome, pollinators) remain largely unknown despite their ecotoxicological significance. The main cause of the Ni NPs-triggered damages is the reactive oxygen species imbalance as a consequence of the modulation of antioxidants. In non-tolerant plants, the toxicity of NiO NPs can be mitigated by exogenous treatments such as the application of silicon, salicylic acid, or jasmonic acid, which induce defense mechanisms whereas Ni-hypertolerant plant species possess endogenous defense systems, such as cell wall modifications and nitrosative signaling against NiO NP stress. Research highlights the role of Ni NPs in managing fungal diseases, showcasing their antifungal properties against specific pathogens. Due to the essentiality of Ni, the application of Ni NPs as nanofertilizers might be promising and has recently started to come into view.


Assuntos
Nanopartículas Metálicas , Níquel , Níquel/toxicidade , Nanopartículas Metálicas/toxicidade , Plantas/efeitos dos fármacos , Agricultura , Química Verde
10.
Environ Sci Pollut Res Int ; 31(30): 43152-43173, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38896217

RESUMO

Currently, lithium-ion batteries are increasingly widely used and generate waste due to the rapid development of the EV industry. Meanwhile, how to reuse "second life" and recycle "extracting of valuable metals" of these wasted EVBs has been a hot research topic. The 4810 relevant articles from SCI and SSCI Scopus databases were obtained. Scientometric analysis about second life using and recycling methodologies of wasted EVBs was conducted by VOSviewer, Pajek, and Netdraw. According to analytical results, the research of second life using and recycling mythologies has been growing and the expected achievement will continue to increase. China, Germany, the USA, Italy, and the UK are the most active countries in this field. Tsinghua University in China, "Fraunhofer ISI, Karlsruhe" in Germany, and "Polytechnic di Torino" in Italy are the most productive single and collaborative institutions. The journals SAE technical papers and World Electric Vehicle Journal have the highest publication and citations than other journals. Chinese author "Li Y" has the highest number of 36 publications, and his papers were cited 589 times by other authors. By analyzing the co-occurrence and keywords, energy analysis, second life (stationary using, small industry), and treatment methods, (hydrometallurgy and pyrometallurgical, electrochemical, bio-metallurgical) were the hot research topics. The S-curve from the article indicates hydrometallurgical and bio-metallurgical methods are attached with great potential in the near future. Further, different treatment methodologies are observed especially advanced techniques in hydrometallurgical, and spent medium bioleaching techniques in bio-metallurgical are good, economically cheap, has low CO2 emission, environmentally friendly, and has high recovery rate. Finally, this research provides information on second life use and top recycling methodology opportunities for future research direction for researchers and decision-makers who are interested in this research.


Assuntos
Fontes de Energia Elétrica , Lítio , Reciclagem
11.
ACS Appl Nano Mater ; 7(9): 9968-9977, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38752020

RESUMO

Different Co contents were used to tune bimetallic Pt-Co nanoparticles with a diameter of 8 nm, resulting in Pt:Co ratios of 3.54, 1.51, and 0.96. These nanoparticles were then applied to the MCF-17 mesoporous silica support. The synthesized materials were characterized with HR-TEM, HAADF-TEM, EDX, XRD, BET, ICP-MS, in situ DRIFTS, and quasi in situ XPS techniques. The catalysts were tested in a thermally induced reverse water-gas shift reaction (CO2:H2 = 1:4) at atmospheric pressure in the 200-700 °C temperature range. All bimetallic Pt-Co particles outperformed the pure Pt benchmark catalyst. The nanoparticles with a Pt:Co ratio of 1.51 exhibited 2.6 times higher activity and increased CO selectivity by 4% at 500 °C. Experiments proved that the electron accumulation and alloying effect on the Pt-Co particles are stronger with higher Co ratios. The production of CO followed the formate reaction pathway on all catalysts due to the face-centered-cubic structure, which is similar to the Pt benchmark. It is concluded that the enhanced properties of Co culminate at a Pt:Co ratio of 1.51 because decreasing the ratio to 0.96 results in lower activity despite having more Co atoms available for the electronic interaction, resulting in the lack of electron-rich Pt sites.

12.
ACS Appl Mater Interfaces ; 16(23): 29946-29962, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38821886

RESUMO

Herein, we investigate the potential of nanostructured high-entropy oxides (HEOs) for photocatalytic CO2 hydrogenation, a process with significant implications for environmental sustainability and energy production. Several cerium-oxide-based rare-earth HEOs with fluorite structures were prepared for UV-light driven photocatalytic CO2 hydrogenation toward valuable fuels and petrochemical precursors. The cationic composition profoundly influences the selectivity and activity of the HEOs, where the Ce0.2Zr0.2La0.2Nd0.2Sm0.2O2-δ catalyst showed outstanding CO2 activation (14.4 molCO kgcat-1 h-1 and 1.27 molCH3OH kgcat-1 h-1) and high methanol and CO selectivity (7.84% CH3OH and 89.26% CO) under ambient conditions with 4 times better performance in comparison to pristine CeO2. Systematic tests showed the effect of a high-entropy system compared to midentropy oxides. XPS, in situ DRIFTS, as well as DFT calculation elucidate the synergistic impact of Ce, Zr, La, Nd, and Sm, resulting in an optimal Ce3+/Ce4+ ratio. The observed formate-routed mechanism and a surface with high affinity to CO2 reduction offer insights into the photocatalytic enhancement. While our findings lay a solid foundation, further research is needed to optimize these catalysts and expand their applications.

13.
Chemosphere ; 358: 142125, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38670509

RESUMO

Microcystin-LR (MC-LR) is a harmful cyanotoxin that inhibits 1 and 2A serine-threonine protein phosphatases. This study examines the influence of MC-LR on chloroplast division and the underlying mechanisms and consequences in Arabidopsis. MC-LR increased the frequency of dividing chloroplasts in hypocotyls in a time range of 1-96 h. At short-term exposures to MC-LR, small-sized chloroplasts (longitudinal diameters ≤6 µm) were more sensitive to these stimulatory effects, while both small and large chloroplasts showed stimulations at long-term exposure. After 48 h, the cyanotoxin increased the frequency of small-sized chloroplasts, indicating the stimulation of division. MC-LR inhibited protein phosphatases in whole hypocotyls and isolated chloroplasts, while it did not induce oxidative stress. We show for the first time that total cellular phosphatases play important roles in chloroplast division and that particular chloroplast phosphatases may be involved in these processes. Interestingly, MC-LR has a protective effect on cyanobacterial division during methyl-viologen (MV) treatments in Synechococcus PCC6301. MC-LR production has harmful effects on ecosystems and it may have an ancient cell division regulatory role in stressed cyanobacterial cells, the evolutionary ancestors of chloroplasts. We propose that cytoplasmic (eukaryotic) factors also contribute to the relevant effects of MC-LR in plants.


Assuntos
Arabidopsis , Cloroplastos , Toxinas Marinhas , Microcistinas , Fosfoproteínas Fosfatases , Microcistinas/toxicidade , Cloroplastos/efeitos dos fármacos , Cloroplastos/metabolismo , Fosfoproteínas Fosfatases/metabolismo , Arabidopsis/efeitos dos fármacos , Cianobactérias/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Synechococcus/efeitos dos fármacos
14.
Materials (Basel) ; 17(8)2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38673163

RESUMO

The presence of alkaline earth cations, in particular, Ca2+ and Mg2+ ions in brine, causes undesired effects in solutions containing anionic surfactants because of precipitate formation. In the present study, an anionic surfactant, sodium dodecyl sulfate (SDS), was investigated, focusing on the determination of various properties (surface tension, critical micelle concentration, micelle size, turbidity) in the presence of alcohols and, in particular, the inhibition of the precipitation of SDS with calcium ions. The calcium ions were added to the surfactant in increasing concentrations (3.0-10.0 g/L), and short-carbon-chain alcohols (methanol, ethanol, n-propanol and n-butanol) were used to shift the onset of precipitate formation. The critical micelle concentration (CMC) of SDS in the presence of alcohols was also determined. It was established that among these alcohols, methanol and ethanol did not exert significant effects on the solubility of the Ca(DS)2 precipitate, while n-propanol and n-butanol were found to be much more efficient inhibitors. In addition, all the alcohols in the applied concentration range (up to 20 V/V%) were found to decrease the critical micelle concentration of SDS.

15.
Materials (Basel) ; 17(5)2024 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-38473501

RESUMO

In this study, a chemical precipitation approach was adopted to produce a photocatalyst based on bismuth tungstate Bi2WO6 for enhanced and environmentally friendly organic pollutant degradation. Various tools such as X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), optical spectroscopy and X-ray photoelectron spectroscopy, were employed to assess the structural and morphological properties. Hence, the XRD profiles showed a well crystallized Bi2WO6 orthorhombic phase. The photocatalytic performance of the resulting photocatalyst was assessed by the decomposition of Rhodamine B (RhB) and methyl orange (MO) with a decomposition efficiency of 97 and 92%, along with the highest chemical oxygen demand of 82 and 79% during 120 min of illumination, respectively. The principal novelty of the present work is to focus on the changes in the crystalline structure, the morphology, and the optical and the photoelectrochemical characteristics of the Bi2WO6, by tuning the annealing temperature of the designed photocatalyst. Such physicochemical property changes in the as-prepared photocatalyst will affect in turn its photocatalytic activity toward the organic pollutant decomposition. The photocatalytic mechanism was elaborated based on electrochemical impedance spectroscopy, photocurrent analysis, photoluminescence spectroscopy, and radical trapping measurements. The overall data indicate that the superoxide O2•- and holes h+ are the principal species responsible for the pollutant photodegradation.

16.
Environ Sci Pollut Res Int ; 31(9): 13673-13687, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38261222

RESUMO

Regulation of antibiotic use in aquaculture calls for the emergence of more sustainable alternative treatments. Tea polyphenols (GTE), particularly epigallocatechin gallate (EGCG), have various biological activities. However, tea polyphenols are susceptible to degradation. In this work, EGCG and GTE were encapsulated in zein nanoparticles (ZNP) stabilized with alginate (ALG) and chitosan (CS) to reduce the degradation effect. ALG-coated ZNP and ALG/CS-coated ZNP encapsulating EGCG or GTE were obtained with a hydrodynamic size of less than 300 nm, an absolute ζ-potential value >30 mV, and an encapsulation efficiency greater than 75%. The antioxidant capacity of the encapsulated substances, although lower than that of the free ones, maintained high levels. On the other hand, the evaluation of antimicrobial activity showed greater efficiency in terms of growth inhibition for ALG/CS-ZNP formulations, with average overall values of around 60%, reaching an inhibition of more than 90% for Photobacterium damselae. These results support encapsulation as a good strategy for tea polyphenols, as it allows maintaining significant levels of antioxidant activity and increasing the potential for antimicrobial activity, in addition to increasing protection against sources of degradation.


Assuntos
Quitosana , Nanopartículas , Compostos Organometálicos , Piridinas , Zeína , Animais , Antioxidantes/farmacologia , Antioxidantes/análise , Alginatos , Polifenóis/farmacologia , Antibacterianos/farmacologia , Chá
17.
Environ Pollut ; 341: 122874, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-37949159

RESUMO

The industrial application and environmental release of nickel oxide NPs (NiO NPs) is increasing, but the details of their relationship with plants are largely unknown. In this work, the cellular, tissue, organ, and molecular level responses of three ecotypes of Ni hyperaccumulator Odontarrhena lesbiaca grown in the presence of high doses of NiO NP (250 mg/L and 500 mg/L) were studied. All three ecotypes showed a similar accumulation of Ni in the presence of nano Ni, and in the case of NiO NPs, the root-to-shoot Ni translocation was slighter compared to the bulk Ni. In all three ecotypes, the walls of the root cells effectively prevented internalization of NiO NPs, providing cellular defense against Ni overload. Exposure to NiO NP led to an increase in cortex thickness and the deposition of lignin-suberin and pectin in roots, serving as a tissue-level defense mechanism against excessive Ni. Exposure to NiO NP did not modify or cause a reduction in some biomass parameters of the Ampeliko and Loutra ecotypes, while it increased all parameters in Olympos. The free salt form of Ni exerted more negative effects on biomass production than the nanoform, and the observed effects of NiO NPs can be attributed to the release of Ni ions. Nitric oxide and peroxynitrite levels were modified by NiO NPs in an ecotype-dependent manner. The changes in the abundance and activity of S-nitrosoglutathione reductase protein triggered by NiO NPs suggest that the enzyme is regulated by NiO NPs at the post-translational level. The NiO NPs slightly intensified protein tyrosine nitration, and the slight differences between the ecotypes were correlated with their biomass production in the presence of NiO NPs. Overall, the Odontarrhena lesbiaca ecotypes exhibited tolerance to NiO NPs at the cellular, tissue, organ/organism and molecular levels, demonstrating various defense mechanisms and changes in the metabolism of reactive nitrogen species metabolism and nitrosative protein modification.


Assuntos
Brassicaceae , Nanopartículas , Ecótipo , Parede Celular
18.
Angew Chem Int Ed Engl ; 63(8): e202317343, 2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38117671

RESUMO

The implementation of supported metal catalysts heavily relies on the synergistic interactions between metal nanoparticles and the material they are dispersed on. It is clear that interfacial perimeter sites have outstanding skills for turning catalytic reactions over, however, high activity and selectivity of the designed interface-induced metal distortion can also obtain catalysts for the most crucial industrial processes as evidenced in this paper. Herein, the beneficial synergy established between designed Pt nanoparticles and MnO in the course of the reverse water gas shift (RWGS) reaction resulted in a Pt/MnO catalyst having ≈10 times higher activity compared to the reference Pt/SBA-15 catalyst with >99 % CO selectivity. Under activation, a crystal assembly through the metallic Pt (110) and MnO evolved, where the plane distance differences caused a mismatched-row structure in softer Pt nanoparticles, which was identified by microscopic and surface-sensitive spectroscopic characterizations combined with density functional theory simulations. The generated edge dislocations caused the Pt lattice expansion which led to the weakening of the Pt-CO bond. Even though MnO also exhibited an adverse effect on Pt by lowering the number of exposed metal sites, rapid desorption of the linearly adsorbed CO species governed the performance of the Pt/MnO in the RWGS.

19.
ACS Appl Nano Mater ; 6(21): 20089-20098, 2023 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-38026613

RESUMO

Highly porous metal oxide-polymer nanocomposites are attracting considerable interest due to their unique structural and functional features. A porous polymer matrix brings properties such as high porosity and permeability, while the metal oxide phase adds functionality. For the metal oxide phase to perform its function, it must be fully accessible, and this is possible only at the pore surface, but functioning surfaces require controlled engineering, which remains a challenge. Here, highly porous nanocomposite beads based on thin metal oxide nanocoatings and polymerized high internal phase emulsions (polyHIPEs) are demonstrated. By leveraging the unique properties of polyHIPEs, i.e., a three-dimensional (3D) interconnected network of macropores, and high-precision of the atomic-layer-deposition technique (ALD), we were able to homogeneously coat the entire surface of the pores in polyHIPE beads with TiO2-, ZnO-, and Al2O3-based nanocoatings. Parameters such as nanocoating thickness, growth per cycle (GPC), and metal oxide (MO) composition were systematically controlled by varying the number of deposition cycles and dosing time under specific process conditions. The combination of polyHIPE structure and ALD technique proved advantageous, as MO-nanocoatings with thicknesses between 11 ± 3 and 40 ± 9 nm for TiO2 or 31 ± 6 and 74 ± 28 nm for ZnO and Al2O3, respectively, were successfully fabricated. It has been shown that the number of ALD cycles affects both the thickness and crystallinity of the MO nanocoatings. Finally, the potential of ALD-derived TiO2-polyHIPE beads in photocatalytic oxidation of an aqueous bisphenol A (BPA) solution was demonstrated. The beads exhibited about five times higher activity than nanocomposite beads prepared by the conventional (Pickering) method. Such ALD-derived polyHIPE nanocomposites could find wide application in nanotechnology, sensor development, or catalysis.

20.
Ecotoxicol Environ Saf ; 267: 115633, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37890253

RESUMO

In addition to their beneficial effects on plant physiology, multi-walled carbon nanotubes (MWCNTs) are harmful to plants in elevated concentrations. This study compared the effects of two doses of MWCNT (10 and 80 mg/L) in Brassica napus and Solanum lycopersicum seedlings focusing on nitro-oxidative processes. The presence of MWCNTs was detectable in the root and hypocotyl of both species. Additionally, transmission electron microscopy analysis revealed that MWCNTs are heavily transformed within the root cells forming large aggregates. The uptake of MWCNTs negatively affected root viability and root cell proliferation of both species, but more intense toxicity was observed in S. lycopersicum compared to B. napus. The presence of MWCNT triggered more intense protein carbonylation in the relative sensitive S. lycopersicum, where increased hydrogen peroxide levels were observed. Moreover, MWCNT exposure increased the level of physiological protein tyrosine nitration which was more intense in S. lycopersicum where notable peroxynitrite accumulation occurred. These suggest for the first time that MWCNT triggers secondary nitro-oxidative stress which contributes to its toxicity. Moreover, the results indicate that the extent of the nitro-oxidative processes is associated with the extent of MWCNT toxicity.


Assuntos
Brassica napus , Nanotubos de Carbono , Solanum lycopersicum , Nanotubos de Carbono/toxicidade , Transporte Biológico , Estresse Oxidativo
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