RESUMO
4-Nitrophenol (4-NP), as a toxic and refractory pollutant, has generated significant concern due to its adverse effects. However, the potential toxic effects and mechanism remained unclear. In this study, the reproduction, development, locomotion and reactive oxygen species (ROS) production of Caenorhabditis elegans were investigated to evaluate the 4-NP toxicity. We used metabolomics to assess the potential damage mechanisms. The role of metabolites in mediating the relationship between 4-NP and phenotypes was examined by correlation and mediation analysis. 4-NP (8 ng/L and 8 µg/L) caused significant reduction of brood size, ovulation rate, total germ cells numbers, head thrashes and body bends, and an increase in ROS. However, the oosperm numbers in uterus, body length and body width were decreased in 8 µg/L. Moreover, 36 differential metabolites were enriched in the significant metabolic pathways, including lysine biosynthesis, ß-alanine metabolism, tryptophan metabolism, pentose phosphate pathway, pentose and glucuronate interconversions, amino sugar and nucleotide sugar metabolism, starch and sucrose metabolism, galactose metabolism, propanoate metabolism, glycerolipid metabolism, and estrogen signaling pathway. The mechanism of 4-NP toxicity was that oxidative stress caused by the perturbation of amino acid, which had effects on energy metabolism through disturbing carbohydrate and lipid metabolism, and finally affected the estrogen signaling pathway to exert toxic effects. Moreover, correlation and mediation analysis showed glycerol-3P, glucosamine-6P, glucosamine-1P, UDP-galactose, L-aspartic acid, and uracil were potential markers for the reproduction and glucose-1,6P2 for developmental toxicity. The results provided insight into the pathways involved in the toxic effects caused by 4-NP and developed potential biomarkers to evaluate 4-NP toxicity.
Assuntos
Caenorhabditis elegans , Estrogênios , Nitrofenóis , Reprodução , Transdução de Sinais , Animais , Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/fisiologia , Reprodução/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Nitrofenóis/toxicidade , Estrogênios/toxicidade , Espécies Reativas de Oxigênio/metabolismo , Estresse Oxidativo/efeitos dos fármacosRESUMO
Due to the rising human population and industrialization, harmful chemical compounds such as 4-nitrophenol (4-NP) and various dyes are increasingly released into the environment, resulting in water pollution. It is essential to convert these harmful chemicals into harmless compounds to mitigate this pollution. This research focuses on synthesizing a novel heterogeneous catalyst using modified canvas fabric (CF) decorated with silver metal nanoparticles on graphene oxide nanosheets (Ag-GO/CF). The process involves coating the fabrics (CF) with graphene oxide (GO) nanosheets through sonication. Subsequently, silver nanoparticles are deposited in situ and reduced on the GO surface, resulting in the formation of the Ag-GO/CF composite. Various physicochemical characterizations were conducted to examine the interfacial interactions between CF, GO, and Ag nanoparticles. The catalytic activity of the nanocomposite was assessed by hydrogenating 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in the presence of sodium borohydride (NaBH4). The results showed that the 10%Ag-5%GO/CF with a surface of 6 cm2 (3 × 2 cm) exhibited the highest catalytic activity, achieving a reduction efficiency of over 96% in 5 min. The 4-NP reduction reaction rate was well-fitted with a pseudo-first-order kinetics model with an apparent reaction rate constant (Kapp) of 0.676 min-1. Furthermore, the Ag-GO/CF composite demonstrated remarkable stability over successive cycles, with no noticeable decrease in its catalytic activity, suggesting its promising application for long-term chemical catalytic processes. This synthesized composite can be easily added to and removed from the reaction solution while maintaining high catalytic performance in the reduction of 4-NP, and it could be beneficial in avoiding problems related to powder separation.
Assuntos
Grafite , Nanopartículas Metálicas , Nitrofenóis , Prata , Grafite/química , Prata/química , Nitrofenóis/química , Catálise , Nanopartículas Metálicas/química , Aminofenóis/química , Óxidos/químicaRESUMO
In the current era of rapid population growth, there has been an increase in resource consumption and the subsequent release of organic pollutants into water bodies by various industries. To address this issue, we have developed a nanocomposite material, Bi2S3-TiO2/HNTs, for electrochemical sensors capable of simultaneously detecting nitrofurantoin (NFT) and 4-nitrophenol (4-NP) contaminants. The nanocomposite material was synthesized using a novel one-pot sol-gel method, and its structural morphology was characterized using techniques such as FE-SEM, FT-IR, HR-TEM, and XRD. The electrochemical sensor exhibited a remarkably low limit of detection (3.2 nM for NFT and 3.5 nM for 4-NP) and a wide concentration range from 0 µM to 260 µM for both NFT and 4-NP, demonstrating their high sensitivity and accuracy for pollutant detection, and furthermore its potential for real-world application was assessed considering pond and tap water as real samples.
Assuntos
Técnicas Eletroquímicas , Nanocompostos , Nitrofurantoína , Nitrofenóis , Titânio , Poluentes Químicos da Água , Titânio/química , Nanocompostos/química , Nitrofenóis/análise , Nitrofenóis/química , Poluentes Químicos da Água/análise , Nitrofurantoína/análise , Nitrofurantoína/química , Sulfetos/químicaRESUMO
To maintain human health and purity of drinking water, it is crucial to eliminate harmful chemicals such as nitrophenols and azo dyes, considering their natural presence in the surroundings. In this particular research study, the application of machine learning techniques was employed in order to make an estimation of the performance of reduction catalysis in the context of ecologically detrimental nitrophenols and azo dyes contaminants. The catalyst utilized in the experiment was Ag@CMC, which proved to be highly effective in eliminating various contaminants found in water, like 4-nitrophenol (4-NP). The experiments were carefully conducted at various time intervals, and the machine learning procedures used in this study were all employed to forecast catalytic performance. The evaluation of the performance of such algorithms were done by means of Mean Absolute Error. The noteworthy findings of this research indicated that the ADAM and LSTM algorithm exhibited the most favourable performance in the case of toxic compounds i.e. 4-NP. Moreover, the Ag@CMC catalyst demonstrated an impressive reduction efficiency of 98 % against nitrophenol in just 8 min. Thus, based on these compelling results, it can be concluded that Ag@CMC works as a highly effective catalyst for practical applications in real-world scenarios.
Assuntos
Compostos Azo , Corantes , Aprendizado de Máquina , Nitrofenóis , Águas Residuárias , Poluentes Químicos da Água , Nitrofenóis/química , Nitrofenóis/isolamento & purificação , Compostos Azo/química , Compostos Azo/isolamento & purificação , Catálise , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Águas Residuárias/química , Corantes/química , Corantes/isolamento & purificação , Purificação da Água/métodos , Prata/química , AlgoritmosRESUMO
The growing population and urbanization have adversely affected the environment including water. The waste water from industries has affected not only human but also animals. The availability of clean water is one of the foremost needs for living organism. This makes very urgent to find reliable solutions for cleaning waste water. These days catalysis is one the best solutions to remove and degrade organic pollutants. In this work, porous composite polymer films have been designed through facile method which were employed to stabilize zero-valent metal nanoparticles (NPs). The sustainable, environmentally friendly polymer matrix with attached metal NPs was applied for the effective catalytic degradation of both phenolic compounds and organic dyes. The different composite films consist of ZnO NPs embedded in an Oxidized Alginate-Chitosan (OAlg-CS) biomatrix named as OAlg-CS/ZnO with various percentages of ZnO as a support for metallic Cu NPs. The ZnO NPs have been incorporated into OAlg-CS polymer with 10, 15, and 20 wt% and are designated as OAlg-CS/ZnO-10, OAlg-CS/ZnO-15, OAlg-CS/ZnO-20. Various analytical techniques were utilized to investigate the shape, morphology, elemental composition, functional groups and stability of the composite films. All these polymer nanocomposite films were then evaluated for removal of model organic pollutants comprising p-nitrophenol (4-NP), methylene blue (MB), and methyl orange (MO). The Kapp value for 4-NP was 2.19 × 10-1 min-1, 4.68 × 10-1 min-1 for MO and 8.99× 10-1 min-1 for MB. The experimental results demonstrated that OAlg-CS/ZnO-20 films show the highest catalytic activity as compared to OAlg-CS/ZnO, OAlg-CS/ZnO-10, and OAlg-CS/ZnO-15. The order of rate constants for nitrophenol and dyes using OAlg-CS/ZnO-20 was found to be MB Ë MO Ë 4-NP, showing the selectivity of these composite films. The prepared composite films were also investigated for their antibacterial activity against Gram-positive and Gram-negative bacteria and all the films exhibited good anti-bacterial activity, with OAlg-CS/ZnO-20 showed the highest anti-bacterial activity.
Assuntos
Alginatos , Antibacterianos , Quitosana , Cobre , Nanopartículas Metálicas , Oxirredução , Óxido de Zinco , Quitosana/química , Óxido de Zinco/química , Alginatos/química , Antibacterianos/química , Antibacterianos/farmacologia , Nanopartículas Metálicas/química , Cobre/química , Poluentes Químicos da Água/química , Nanocompostos/química , Catálise , Nitrofenóis/química , Corantes/química , Compostos AzoRESUMO
The presence of toxic chemicals in water, including heavy metals like mercury and lead, organic pollutants such as pesticides, and industrial chemicals from runoff and discharges, poses critical public health and environmental risks leading to severe health issues and ecosystem damage; education plays a crucial role in mitigating these effects by enhancing awareness, promoting sustainable practices, and integrating environmental science into curricula to empower individuals to address and advocate for effective solutions to water pollution. However, the educational transformation should be accompanied with a technical process which can be eventually transferred to society to empower environmental education. In this study, carbonaceous material derived from Haematoxylum campechianum (CM-HC) was utilized for removing 3-nitrophenol (3-Nph) from aqueous solutions. The novelty of this research utilizes Haematoxylum campechianum bark and coconut shell, abundant agricultural wastes in Campeche, Mexico, for toxin removal, enhancing the adsorption process through artificial neural networks and genetic algorithms to optimize conditions and maximize the absorption efficiency. CM-HC's surface morphology was analyzed using scanning electron microscopy (SEM/EDS), BET method, X-ray powder diffraction (XRD), and pHpzc. Kinetic models including pseudo-first-order (PFO), pseudo-second-order (PSO), and Elovich were applied to fit the data. Adsorption isotherms were determined at varying pH (3-8), adsorbent dosages (2-10 g/L), and temperatures (300.15-330.15 K), employing Langmuir, Freundlich, Temkin, and Redlich-Peterson models. PSO kinetics demonstrated a good fit (R2 > 0.98) for Ci = 50-100 mg/L, indicating a chemical adsorption mechanism. The Langmuir isotherm model exhibited the best fit, confirming chemical adsorption, with a maximum adsorption capacity (Qm) of 236.156 mg/g at T = 300.15 K, pH = 6, contact time = 3 h, and 2 g/L adsorbent dosage. Lower temperatures favored exothermic adsorption. Artificial neural networks (ANNs) were employed for deep learning, optimizing the predictive model for removal percentage. Correlation heat maps highlighted positive correlations between time, dosage, and removal percentage, emphasizing the impact of initial concentration on efficiency. ANN modeling, incorporating iterative optimization, yielded highly accurate predictions, aligned closely with experimental results. The study showcases the success of deep learning in optimizing adsorption processes, emphasizing the importance of diverse correlation algorithms for comprehensive insights into competitive adsorption dynamics. The 5-14-14-1 deep learning architecture, fine-tuned over 228 epochs, demonstrated strong performance with mean squared error (MSE) values of 4.07, 18.406, and 6.2122 for training, testing, and total datasets, respectively, and high R-squared values. Graphical analysis showed a solid linear correlation between experimental and simulated removal percentages, emphasizing the need to consider more than just testing data for optimization. Experimental validation confirmed a 98.77% removal efficiency, illustrating the effectiveness of combining deep learning with genetic algorithms, and highlighting the necessity of experimental trials to verify computational predictions. It is concluded that the carbonaceous material from Haematoxylum campechianum waste (CM-HC) is an effective, low-cost adsorbent for removing 3-nitrophenol from aqueous solutions, achieving optimal removal at pH 6 and 300.15 K with a maximum adsorption capacity of 236.156 mg/g, following Langmuir model and pseudo-second order kinetics. The validated ANN model offers a reliable tool for practical applications in environmental remediation, advancing both environmental science and educational innovation by integrating artificial neural networks and data science methodologies into student learning experiences.
Assuntos
Biomassa , Aprendizado Profundo , Redes Neurais de Computação , Nitrofenóis , Adsorção , Nitrofenóis/química , Poluentes Químicos da Água/química , Poluentes Químicos da Água/análise , Carbono/química , Purificação da Água/métodosRESUMO
Despite the vital roles of Fe0/biochar composites in the Fenton-like systems for eliminating pollutants that have been recognized, the contributions of persistent free radicals (PFRs) of carbon-based materials are typically overlooked. In this study, the high-PFR-containing biochar nanoiron composites were prepared (nZVI/500), and the in situ generation of hydroxyl radicals (·OH) and degradation of p-nitrophenol (PNP) were investigated. The results showed that nZVI/500 could effectively remove PNP in solution within the pH range of 3-8. Quantitative experiments of ·OH presented that, compared with low PFRs-containing composites, nZVI/500 could generate 64.6 µM ·OH in 60 min without any extra energy consumption. Mechanistic studies revealed that (1) both PFRs and Fe0 are able to utilize dissolved oxygen to generate H2O2 in situ; (2) PFRs can promote the cycling of Fe3+/Fe2+ in the system due to their strong electron exchange ability; and (3) PFRs directly transfer electrons to H2O2; therefore, the presence of PFRs accelerates the generation of ·OH in the system and facilitates the removal of PNP. This study provides an important theoretical basis and technical reference for expanding the application of PFR-rich carbon-based materials to remove environmental pollutants.
Assuntos
Carvão Vegetal , Ferro , Nitrofenóis , Nitrofenóis/química , Ferro/química , Carvão Vegetal/química , Radicais Livres/química , Peróxido de Hidrogênio/química , Radical Hidroxila/químicaRESUMO
In this study, we present the synthesis of gold nanoparticles (AuNPs) using a completely green synthesis method without the use of any additional functionalizing agent, except dried turmeric root extract. The significant synthesis parameters were optimized, and the applicability of AuNPs was investigated in areas such as plasmonic and fluorescent sensing of aluminum (Al3âº) and chromium (Cr3âº) ions, reduction of 4-nitrophenol (4-NP), and degradation of methylene blue (MB) and methyl orange (MO) dyes. Characterization studies were performed using UV-Vis spectroscopy, TEM, FTIR, and XRD, revealing that the AuNPs predominantly had a spherical morphology and a very small particle size of 8.5 nm, with stability maintained up to 120 days. The developed AuNP-based plasmonic sensors relied on aggregation-induced decreases in absorption, along with a red shift in the spectra. Fluorescence sensing demonstrated a linear increase in intensity with increasing concentrations of Al3⺠and Cr3âº, with detection limits of 0.83 and 1.19 nM, respectively. The catalytic activities of AuNPs were tested in reducing 4-NP and degradations of MB and MO dyes (binary system) in tap water and wastewater, with the reactions following pseudo-first-order kinetics. This study highlights the potential of AuNPs synthesized from turmeric roots for various environmental and sensing applications.
Assuntos
Curcuma , Ouro , Nanopartículas Metálicas , Extratos Vegetais , Ouro/química , Nanopartículas Metálicas/química , Curcuma/química , Extratos Vegetais/química , Química Verde , Raízes de Plantas/química , Catálise , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/química , NitrofenóisRESUMO
In this paper, a versatile heterogeneous nanocatalyst was fabricated employing a self-assembly technique. To commence, Fe3O4 MNPs were coated with a thin layer of SiO2 using the stobbers method. Subsequently, the surface was further functionalized with 3-CPMS, followed by a reaction with a Schiff base. Finally, nickel NPs were deposited on the surface through in situ deposition, forming the Fe3O4@SiO2@3-CPMS@L-Ni magnetic nanocatalyst. The architecture of this magnetic nanocatalyst was meticulously characterized through an array of sophisticated techniques: XRD, FT-IR, SEM, TEM, BET and VSM. The XRD diffraction pattern confirmed the presence of Fe3O4 MNPs, SiO2, and Ni peaks, providing evidence for successful synthesis. Moreover, the successful functionalization with a Schiff base was demonstrated by the presence of an azomethane peak in the FTIR spectra of the synthesized nanocatalyst. The fabricated nanocatalyst was adeptly utilized for the reduction of 4-NP, NB, and MO demonstrating a remarkably elevated rate of catalytic efficacy. Moreover, this catalyst was effortlessly retrievable through the application of an external magnet, and it maintained its catalytic prowess across at least six consecutive cycles. The utilization of water as an environmentally friendly solvent, coupled with the utilization of abundant and cost-effective nickel catalyst instead of the costly Pd or Pt catalysts, along with the successful recovery and scalability of the catalyst, render this method highly advantageous from both environmental and economic perspectives for the reduction of 4-NP, NB, and MO.
Assuntos
Níquel , Dióxido de Silício , Níquel/química , Catálise , Dióxido de Silício/química , Nitrobenzenos/química , Nitrofenóis/química , Compostos Azo/química , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
Nitrites (NO2-/HONO), as the primary source of hydroxyl radicals (â¢OH) in the atmosphere, play a key role in atmospheric chemistry. However, the current understanding of the source of NO2-/HONO is insufficient and therefore hinders the accurate quantification of atmospheric oxidation capacity. Herein, we highlighted an overlooked HONO source by the reaction between nitrophenols (NPs) and â¢OH in the aqueous phase and provided kinetic data to better evaluate the contribution of this process to atmospheric HONO. Three typical NPs, including 4-nitrophenol (4NP), 2-nitrophenol (2NP), and 4-nitrocatechol (4NC), underwent a denitration process to form aqueous NO2- and gaseous HONO through the â¢OH oxidation, with the yield of NO2-/HONO varied from 15.0 to 33.5%. According to chemical composition and structure analysis, the reaction pathway, where the ipso addition of â¢OH to the NO2 group on 4NP generated hydroquinone, can contribute to more than 61.9% of the NO2-/HONO formation. The aqueous photooxidation of NPs may account for HONO in the atmosphere, depending on the specific conditions. The results clearly suggest that the photooxidation of NPs should be considered in the field observation and calculation to better evaluate the HONO budget in the atmosphere.
Assuntos
Nitrofenóis , Oxirredução , Nitrofenóis/química , Nitritos/química , Atmosfera/química , Radical Hidroxila/química , Água/química , CinéticaRESUMO
Cisplatin (CDDP) is an FDA-approved chemotherapeutic drug used for treating various solid tumors. Despite of its effectiveness towards chemotherapy, it faces several challenges, such as multi-drug resistance (MDR) and significant damage to the normal tissues. To address these challenges, various nanoformulations were developed to improve the delivery and safety of CDDP. One of the limitation in these CDDP loaded nanoformulations is that the effective CDDP loading concentrations are very poor. Therefore, this leaves a grand challenge to develop an effective strategy to carry higher concentrations of CDDP molecules, and also simultaneously exhibit very unique properties. Herein, we have developed an one-pot synthesis of Cisplatin encapsulated Plasmonic blackbody (CiP), which offers a double play for near infrared (NIR) light activatable chemo-photothermal therapy in destructing cancer cells as well as mediate catalytic reduction of 4-nitrophenol (4-NP). The CiP nanoformulation exhibits superior light absorbing capabilities in the NIR region with an appreciable photothermal conversion efficiency of 41 %. Further, NIR light activatable combinatorial therapeutic approach of CiP was demonstrated against ovarian cancer cells and as a catalyst for the reduction of model pollutant 4-nitrophenol. Our findings highlight the potential of CiP as a versatile platform for light-activated combinatorial cancer therapy and environmental pollutant remediation.
Assuntos
Antineoplásicos , Cisplatino , Raios Infravermelhos , Nitrofenóis , Nitrofenóis/química , Cisplatino/química , Cisplatino/farmacologia , Humanos , Antineoplásicos/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Oxirredução , Sobrevivência Celular/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Fototerapia , Proliferação de Células/efeitos dos fármacosRESUMO
Herein, we reported the dual functions of molybdenum disulfide/sulfur-doped graphitic carbon nitride (MoS2/SGCN) composite as a sensing material for electrochemical detection of 4-NP and a catalyst for 4-NP degradation. The MoS2 nanosheet, sulfur-doped graphitic carbon nitride (SGCN) and MoS2/SGCN were characterized using field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) spectroscopy and X-ray photoelectron spectroscopy (XPS). Electrochemical characterization of these materials with electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) in 1â¯mM K4[Fe(CN)6]3-/4- show that the composite has the lowest charge transfer resistance and the best electrocatalytic activity. The limit of detection (LOD) and the linear range of 4-nitrophenol at MoS2/SGCN modified glassy carbon electrode (MoS2/SGCN/GCE) were computed as 12.8â¯nM and 0.1 - 2.6 µM, respectively. Also, the percentage recoveries of 4-NP in spiked tap water samples ranged from 97.8 - 99.1â¯%. The electroanalysis of 4-NP in the presence of notable interferons shows that the proposed electrochemical sensor features outstanding selectivity toward 4-NP. Additionally, the results of the catalytic degradation of 4-NP at MoS2/SGCN show that the nanocatalyst catalyzed the transformation of 4-NP to 4-aminophenol (4-AP) with a first-order rate constant (k) estimated to be 4.2 ×10-2 s-1. The results of this study confirm that the MoS2/SGCN nanocatalyst is a useful implement for electroanalytical monitoring and catalytic degradation of the hazardous 4-NP in water samples.
Assuntos
Dissulfetos , Técnicas Eletroquímicas , Grafite , Limite de Detecção , Molibdênio , Nitrofenóis , Poluentes Químicos da Água , Molibdênio/química , Molibdênio/análise , Nitrofenóis/análise , Nitrofenóis/química , Técnicas Eletroquímicas/métodos , Dissulfetos/química , Catálise , Poluentes Químicos da Água/análise , Grafite/química , Compostos de Nitrogênio/química , Compostos de Nitrogênio/análise , EletrodosRESUMO
In this work, a molecularly imprinted electrochemiluminescence (ECL) sensor was developed for selective detection of 4-nitrophenol (4-NP) in drinking water for the first time. By synthesizing velvet-like graphitic carbon nitride (V-g-C3N4) via one-step thermal polycondensation and integrating it with a molecularly imprinted polymer (MIP), the ECL sensor was fabricated. The MIP-modified V-g-C3N4 composites (MIP/V-g-C3N4) were synthesized using a sol-gel method with 4-NP as the template molecule. Under optimal conditions, the ECL sensor exhibited a wide detection range (5 × 10-10-1 × 10-5 mol/L) and a low detection limit (1.8 × 10-10 mol/L). In testing with actual drinking water samples, it displayed high accuracy (recoveries for intraday and inter-day: 93.50-106.2% and 97.00-107.3%, separately) and precision (RSDs for intraday and inter-day: 1.54-4.59% and 1.53-4.28%, respectively). The developed MIP-based ECL sensor demonstrated excellent selectivity, stability, and reproducibility, offering a promising and reliable approach for highly sensitive and selective determination of 4-NP in drinking water.
Assuntos
Água Potável , Técnicas Eletroquímicas , Grafite , Impressão Molecular , Nitrofenóis , Poluentes Químicos da Água , Água Potável/análise , Água Potável/química , Grafite/química , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/química , Nitrofenóis/análise , Nitrofenóis/química , Técnicas Eletroquímicas/instrumentação , Compostos de Nitrogênio/química , Limite de Detecção , Medições Luminescentes/instrumentação , Medições Luminescentes/métodos , Polímeros Molecularmente Impressos/química , Nitrilas/química , Nitrilas/análiseRESUMO
This study explores novel nanoparticles used in environmental remediation of 4-nitrophenol and aniline from wastewater bodies. The Zn0.5Ni0.5FeCrO4 magnetic nanoparticles (MNPs) were synthesized using tragacanth gel as a green, low-cost, and easy sol-gel method. The MNPs were characterized by XRD, XPS, FT-IR, VSM, TEM, EDX, FESEM, BET, DRS, and elemental mapping. The analysis demonstrated that nanoparticles have a spinel cubic structure, spatial distribution of the elements, ferromagnetic activity, narrow bandgap, and uniform morphology. Furthermore, effectiveness of the developed MNPs to degrade recalcitrant organic pollutants such as 4-nitrophenol (4-NP) and aniline under visible light exposure were studied. The results indicated 95% aniline and 80% of 4-NP were successfully degraded in 180 and 150 min, respectively. The total organic carbon (TOC) analysis revealed 65% and 54% removal of aniline and 4-NP. LC-MS was employed to elucidate the photodegradation mechanism and to identify the degradation products, including small fragmented molecules.
Assuntos
Compostos de Anilina , Luz , Nitrofenóis , Fotólise , Compostos de Anilina/química , Nitrofenóis/química , Poluentes Químicos da Água/química , Nanopartículas de Magnetita/química , Níquel/química , Zinco/química , Química Verde/métodosRESUMO
In this study, hydrogel beads were fabricated using alginate (Algt) polymer containing dispersed nickel phthalocyanine (NTC) nanomaterial. The viscous solution of Algt and NTC was poured dropwise into a divalent Ca2+ ions, resulting in the formation of hydrogel beads known as NTC@Algt-BDs. The surface of the NTC@Algt-BDs was further modified by coating them with different types of metal ions, yielding metal-coated M+/NTC@Algt-BDs. The adsorbed metal ions i.e., Cu+2, Ag+, Ni+2, Co+2, and Fe+3 were subsequently reduced to zero-valent metal nanoparticles (M0) by NaBH4. The prepared beads were characterized using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Initially, M0/NTC@Algt-BDs were examined for the catalytic reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). Among them, Cu0/NTC@Algt-BDs catalyst exhibited the highest reduction rate and therefore, investigated for reduction of different nitrophenols (NPs) and dyes, including 2-nitrophenol (2-NP), 2,6-dinitrophenol (2,6-DNP), methyl orange (MO), potassium ferrocyanide (PFC), congo red (CR), and acridine orange (ArO). The highest reduction rates of 2.019 and 1.394 min-1 were observed for MO and 2-NP, respectively. Furthermore, the fabricated catalysts were employed for the efficient production of H2 gas by NaBH4 methanolysis. Among which the Ag0/NTC@Algt-BDs catalyst showed excellent catalytic production of H2 gas, exhibiting the lowest activation energy (Ea) of 25.169 kJ/mol at ambient temperature. Furthermore, the impact of NaBH4 amount, and catalyst dosage on the reduction of 2-NP and H2 gas production was conducted whereas the effect of temperature on methanolysis of NaBH4 for evolution of H2 gas was studied. The amount of H2 gas was confirmed by GC-TCD system. Additionally, the recyclability of the catalyst was investigated, as it garnered significant research interest.
Assuntos
Alginatos , Hidrogênio , Alginatos/química , Catálise , Hidrogênio/química , Poluentes Ambientais/química , Indóis/química , Propriedades de Superfície , Nitrofenóis/química , Microesferas , Hidrogéis/química , AdsorçãoRESUMO
BACKGROUND: Psoriasis is an inflammatory skin disease with unclear pathogenesis and unmet therapeutic needs. OBJECTIVE: To investigate the role of senescent CD4+ T cells in psoriatic lesion formation and explore the application of senolytics in treating psoriasis. METHODS: We explored the expression levels of p16INK4a and p21, classical markers of cellular senescence, in CD4+ T cells from human psoriatic lesions and imiquimod (IMQ)-induced psoriatic lesions. We prepared a senolytic gel using B-cell lymphoma 2 (BCL-2) inhibitor ABT-737 and evaluated its therapeutic efficacy in treating psoriasis. RESULTS: Using multispectrum immunohistochemistry (mIHC) staining, we detected increased expression levels of p16INK4a and p21 in CD4+ T cells from psoriatic lesions. After topical application of ABT-737 gel, significant alleviation of IMQ-induced psoriatic lesions was observed, with milder pathological alterations. Mechanistically, ABT-737 gel significantly decreased the percentage of senescent cells, expression of T cell receptor (TCR) α and ß chains, and expression of Tet methylcytosine dioxygenase 2 (Tet2) in IMQ-induced psoriatic lesions, as determined by mIHC, high-throughput sequencing of the TCR repertoire, and RT-qPCR, respectively. Furthermore, the severity of psoriatic lesions in CD4creTet2f/f mice was milder than that in Tet2f/f mice in the IMQ-induced psoriasis model. CONCLUSION: We revealed the roles of senescent CD4+ T cells in developing psoriasis and highlighted the therapeutic potential of topical ABT-737 gel in treating psoriasis through the elimination of senescent cells, modulation of the TCR αß repertoire, and regulation of the TET2-Th17 cell pathway.
Assuntos
Compostos de Bifenilo , Linfócitos T CD4-Positivos , Senescência Celular , Dioxigenases , Modelos Animais de Doenças , Imiquimode , Nitrofenóis , Piperazinas , Proteínas Proto-Oncogênicas c-bcl-2 , Psoríase , Sulfonamidas , Imiquimode/administração & dosagem , Psoríase/tratamento farmacológico , Psoríase/induzido quimicamente , Psoríase/patologia , Psoríase/imunologia , Animais , Senescência Celular/efeitos dos fármacos , Camundongos , Humanos , Nitrofenóis/farmacologia , Nitrofenóis/administração & dosagem , Sulfonamidas/farmacologia , Sulfonamidas/administração & dosagem , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/genética , Piperazinas/farmacologia , Piperazinas/administração & dosagem , Compostos de Bifenilo/farmacologia , Compostos de Bifenilo/uso terapêutico , Compostos de Bifenilo/administração & dosagem , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Proteínas de Ligação a DNA/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Administração Cutânea , Senoterapia/farmacologia , Senoterapia/administração & dosagem , Senoterapia/uso terapêutico , Pele/patologia , Pele/efeitos dos fármacos , Pele/imunologia , Masculino , Géis , Feminino , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Inibidor p16 de Quinase Dependente de Ciclina/genética , Camundongos Endogâmicos C57BLRESUMO
In recent years, due to the abuse of antibiotics, nitro explosives and pesticides, which have caused great harm to the environment and human health, social concerns have prompted researchers to develop more sensitive detection platforms for these pollutants. In this paper, a novel two-dimensional Zn (II) coordination polymer, [Zn(L)0.5(1,2-bimb)]·DMF (1), [H4L=[1,1':4',1''-terphenyl]-2, 2'',4, 4'' -tetracarboxylic acid, 1,2-bimb = 1,2-bis(imidazol-1-ylmethyl)benzene] was synthesized using a hydro-solvothermal method. Among commonly used organic solvents, 1 exhibits significant stability. Fast and efficient fluorescence response can be achieved for tetracycline (TET), 4-nitrophenol (4-NP), fluazinam (FLU), and abamectin benzoate (AMB) with low detection limits. A binary intelligent logic gate device with FLU and AMB as chemical input signals is successfully constructed, which provides a new idea for biochemical detection. In addition, a portable visual test paper has been prepared, which has high sensitivity, good selectivity, and simple operation. It can be used for rapid detection of pollutants in daily life and has broad application prospects. Finally, a detailed discussion was conducted on the fluorescence sensing mechanism of 1 for detecting TET, 4-NP, AMB and FLU.
Assuntos
Nitrofenóis , Praguicidas , Espectrometria de Fluorescência , Tetraciclina , Nitrofenóis/análise , Nitrofenóis/química , Tetraciclina/análise , Praguicidas/análise , Espectrometria de Fluorescência/métodos , Limite de Detecção , Poluentes Químicos da Água/análise , Zinco/análiseRESUMO
This paper investigates the esterase activity of minimalist amyloid fibers composed of short seven-residue peptides, IHIHIHI (IH7) and IHIHIQI (IH7Q), with a particular focus on the role of the sixth residue position within the peptide sequence. Through computational simulations and analyses, we explore the molecular mechanisms underlying catalysis in these amyloid-based enzymes. Contrary to initial hypotheses, our study reveals that the twist angle of the fiber, and thus the catalytic site's environment, is not notably affected by the sixth residue. Instead, the sixth residue interacts with the p-nitrophenylacetate (pNPA) substrate, particularly through its -NO2 group, potentially enhancing catalysis. Quantum mechanics/molecular mechanics (QM/MM) simulations of the reaction mechanism suggest that the polarizing effect of glutamine enhances catalytic activity by forming a stabilizing network of hydrogen bonds with pNPA, leading to lower energy barriers and a more exergonic reaction. Our findings provide valuable insights into the intricate interplay between peptide sequence, structural arrangement, and catalytic function in amyloid-based enzymes, offering potentially valuable information for the design and optimization of biomimetic catalysts.
Assuntos
Amiloide , Domínio Catalítico , Esterases , Ligação de Hidrogênio , Esterases/química , Esterases/metabolismo , Amiloide/química , Amiloide/metabolismo , Catálise , Simulação de Dinâmica Molecular , Teoria Quântica , Oligopeptídeos/química , Oligopeptídeos/metabolismo , Sequência de Aminoácidos , Nitrofenóis/química , Nitrofenóis/metabolismoRESUMO
The stimulus-responsive regulation of enzyme catalytic activity and selectivity provides a new opportunity to extend the functionality and efficiency of immobilized enzymes. This work aims to design and synthesize a thermo-switchable enzyme@MOF for size-selective biocatalysis and biosensing through the immobilization of Candida rugosa lipase (CRL) within ZIF-8 functionalized with thermally responsive polymer, poly(N-isopropylacrylamide) (PNIPAM) (CRL@ZIF-8-PNIPAM). Unlike free CRL, which does not demonstrate substrate selectivity, we can reversibly tune the pore size of the ZIF-8-PNIPAM nanostructures (open pores or blocked pores) through temperature stimulus and subsequently modulate the substrate selectivity of CRL@ZIF-8-PNIPAM. CRL@ZIF-8-PNIPAM had the highest hydrolytic activity for small molecules (12 mM p-nitrophenol/mg protein/min, 4-nitrophenyl butyrate (p-NP Be)) and the lowest hydrolytic activity for large molecules (0.16 mM p-nitrophenol/mg protein/min, 4-nitrophenyl palmitate (p-NP P)). In addition, CRL@ZIF-8-PNIPAM demonstrated thermo-switchable behavior for large molecules (p-NP P). The p-NP P hydrolytic activity of CRL@ZIF-8-PNIPAM was significantly lower at 40 °C (blocked pores) than at 27 °C (open pores). However, the transition of blocked pores and open pores is a gradual process that resulted in a delay in the "thermo-switchable" catalytic behavior of CRL@ZIF-8-PNIPAM during thermal cycling. CRL@ZIF-8-PNIPAM was also successfully used for the fabrication of electrochemical biosensors for the selective biosensing of pesticides with different molecular sizes.
Assuntos
Resinas Acrílicas , Biocatálise , Técnicas Biossensoriais , Enzimas Imobilizadas , Lipase , Estruturas Metalorgânicas , Técnicas Biossensoriais/métodos , Estruturas Metalorgânicas/química , Lipase/química , Lipase/metabolismo , Enzimas Imobilizadas/química , Resinas Acrílicas/química , Temperatura , Nitrofenóis/química , Zeolitas/química , Proteínas Fúngicas/química , SaccharomycetalesRESUMO
Non-thermal dielectric barrier discharge (DBD) plasma has received great attention for degradation of persistent organic pollutants such as p-nitrophenol (PNP). However, the feasibility of the DBD implementation is not clear due to its high energy consumption and relatively low degradation efficiency. In this research, a novel strategy was suggested based on re-circulation of the generated O3 in the DBD system to enhance the PNP degradation efficiency and energy yield. The potential mechanism and possible pathway of PNP degradation were studied by EPR, ESR, DFT and GS-MS analytical tests. According to the results, the PNP degradation efficiency and energy yield increased from 57.4% to 94.4% and from 0.52 to 1.18 g kW-1h-1, respectively through ozone circulation into the DBD reactor. This was due to the more release of long-lived and short-lived reactive species (ROS) in the DBD-O3 system by the O3 circulation. The variations in pH (4-10), initial concentration (50-90 mg L-1), and the presence of co-existing substances in the water matrix had minimal impact on the DBD-O3 system, in comparison to the conventional system. The biological toxicity evaluation revealed that the hybrid DBD-O3 system transform PNP to less toxic intermediates. This study proposes a promising strategy to improve the utilization of DBD for the degradation of PNP.