Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.284
Filtrar
1.
Int J Biol Macromol ; 267(Pt 1): 131471, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38599419

RESUMO

The conversion of glucose into fructose can transform cellulose into high-value chemicals. This study introduces an innovative synthesis method for creating an MgO-based ordered mesoporous carbon (MgO@OMC) catalyst, aimed at the efficient isomerization of glucose into fructose. Throughout the synthesis process, lignin serves as the exclusive carbon precursor, while Mg2+ functions as both a crosslinking agent and a metallic active center. This enables a one-step synthesis of MgO@OMC via a solvent-induced evaporation self-assembly (EISA) method. The synthesized MgO@OMCs exhibit an impeccable 2D hexagonal ordered mesoporous structure, in addition to a substantial specific surface area (378.2 m2/g) and small MgO nanoparticles (1.52 nm). Furthermore, this catalyst was shown active, selective, and reusable in the isomerization of glucose to fructose. It yields 41 % fructose with a selectivity of up to 89.3 % at a significant glucose loading of 7 wt% in aqueous solution over MgO0.5@OMC-600. This performance closely rivals the current maximum glucose isomerization yield achieved with solid base catalysts. Additionally, the catalyst retains a fructose selectivity above 60 % even after 4 cycles, a feature attributable to its extended ordered mesoporous structure and the spatial confinement effect of the OMCs, bestowing it with high catalytic efficiency.


Assuntos
Carbono , Frutose , Glucose , Lignina , Óxido de Magnésio , Frutose/química , Lignina/química , Glucose/química , Carbono/química , Porosidade , Óxido de Magnésio/química , Catálise , Isomerismo
2.
Environ Sci Pollut Res Int ; 31(20): 30149-30162, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38602634

RESUMO

Nanoparticles, particularly magnesium oxide nanoparticles (MgO-NPs), are increasingly utilized in various fields, yet their potential impact on cellular systems remains a topic of concern. This study aimed to comprehensively investigate the molecular mechanisms underlying MgO-NP-induced cellular impairment in Saccharomyces cerevisiae, with a focus on cell wall integrity, endoplasmic reticulum (ER) stress response, mitochondrial function, lipid metabolism, autophagy, and epigenetic alterations. MgO-NPs were synthesized through a chemical reduction method, characterized for morphology, size distribution, and elemental composition. Concentration-dependent toxicity assays were conducted to evaluate the inhibitory effect on yeast growth, accompanied by propidium iodide (PI) staining to assess membrane damage. Intracellular reactive oxygen species (ROS) accumulation was measured, and chitin synthesis, indicative of cell wall perturbation, was examined along with the expression of chitin synthesis genes. Mitochondrial function was assessed through Psd1 localization, and ER structure was analyzed using dsRed-HDEL marker. The unfolded protein response (UPR) pathway activation was monitored, and lipid droplet formation and autophagy induction were investigated. Results demonstrated a dose-dependent inhibition of yeast growth by MgO-NPs, with concomitant membrane damage and ROS accumulation. Cell wall perturbation was evidenced by increased chitin synthesis and upregulation of chitin synthesis genes. MgO-NPs impaired mitochondrial function, disrupted ER structure, and activated the UPR pathway. Lipid droplet formation and autophagy were induced, indicating cellular stress responses. Additionally, MgO-NPs exhibited differential cytotoxicity on histone mutant strains, implicating specific histone residues in cellular response to nanoparticle stress. Immunoblotting revealed alterations in histone posttranslational modifications, particularly enhanced methylation of H3K4me. This study provides comprehensive insights into the multifaceted effects of MgO-NPs on S. cerevisiae, elucidating key molecular pathways involved in nanoparticle-induced cellular impairment. Understanding these mechanisms is crucial for assessing nanoparticle toxicity and developing strategies for safer nanoparticle applications.


Assuntos
Parede Celular , Estresse do Retículo Endoplasmático , Óxido de Magnésio , Nanopartículas , Saccharomyces cerevisiae , Saccharomyces cerevisiae/efeitos dos fármacos , Óxido de Magnésio/toxicidade , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Parede Celular/efeitos dos fármacos , Nanopartículas/toxicidade , Espécies Reativas de Oxigênio/metabolismo , Autofagia/efeitos dos fármacos
3.
Bioprocess Biosyst Eng ; 47(5): 753-766, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38573334

RESUMO

Green synthesis of metal oxides as a treatment for bone diseases is still exploring. Herein, MgO and Fe2O3 NPs were prepared from the extract of Hibiscus sabdariffa L. to study their effect on vit D3, Ca+2, and alkaline phosphatase enzyme ALP associated with osteoporosis. Computational chemistry was utilized to gain insight into the possible interactions. These oxides were characterized by X-ray diffraction, SEM, FTIR, and AFM. Results revealed that green synthesis of MgO and Fe2O3 NPs was successful with abundant. MgO NPs were in vitro applied on osteoporosis patients (n = 35) and showed a significant elevation of vit D3 and Ca+2 (0.0001 > p < 0.001) levels, compared to healthy volunteers (n = 25). Thus, Hibiscus sabdariffa L. is a good candidate to prepare MgO NPs, with a promising enhancing effect on vit D3 and Ca+2 in osteoporosis. In addition, interactions of Fe2O3 and MgO NPs with ALP were determined by molecular docking study.


Assuntos
Hibiscus , Óxido de Magnésio , Osteoporose , Hibiscus/química , Humanos , Osteoporose/tratamento farmacológico , Óxido de Magnésio/química , Compostos Férricos/química , Extratos Vegetais/química , Feminino , Masculino , Cálcio/química , Simulação de Acoplamento Molecular , Nanopartículas Metálicas/química , Pessoa de Meia-Idade , Óxidos/química , Fosfatase Alcalina/metabolismo , Colecalciferol/química , Colecalciferol/farmacologia
4.
Open Vet J ; 14(1): 545-552, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38633155

RESUMO

Background: Nanoparticles are regarded as magical bullets because of their exclusive features. Recently, the usage of nanoparticles has progressed in almost all aspects of science and technology due to its ability to revolutionize certain fields. In the field of food science and technology, the application of nanoparticles is being researched in many various areas thus provides the dairy industry with a variety of new attitudes for developing the quality, prolong shelf life, ensure the safety and healthiness of foods. Aim: This study aimed to focus on the application of some inorganic metal oxide nanoparticles (zinc oxide (ZnO), magnesium oxide (MgO), and calcium oxide (CaO)) to control E. coli in raw milk and ensure its safety. Methods: The antibacterial action of certain nanoparticles (ZnO, MgO, and CaO) with multiple concentrations (0.1, 0.05, 0.025, 0.0125, 0.006, and 0.003 mg/ml) was evaluated against E. coli strains in ultra heat treated (UHT) milk samples. Also, storage temperature and storage period effects were studied. Results: The findings of the current research revealed that inorganic metal oxide nanoparticles had a significant antibacterial role against E. coli, in the following order; ZnO, MgO, and CaO, respectively. The antibacterial effect of inorganic metal oxide nanoparticles is more noticeable at lower temperatures. Conclusion: Inorganic metal nanoparticles can be used in the food industry for the purpose of the control of E. coli, and extension of the shelf life of dairy products.


Assuntos
Compostos de Cálcio , Nanopartículas Metálicas , Óxido de Zinco , Animais , Escherichia coli , Óxido de Magnésio , Leite , Óxidos , Antibacterianos
5.
Oncol Rep ; 51(5)2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38577936

RESUMO

Cancer cells are characterized by increased glycolysis, known as the Warburg effect, which leads to increased production of cytotoxic methylglyoxal (MGO) and apoptotic cell death. Cancer cells often activate the protective nuclear factor erythroid 2­related factor2 (Nrf2)/glyoxalase1 (Glo1) system to detoxify MGO. The effects of sodium butyrate (NaB), a product of gut microbiota, on Nrf2/Glos/MGO pathway and the underlying mechanisms in prostate cancer (PCa) cells were investigated in the present study. Treatment with NaB induced the cell death and reduced the proliferation of PCa cells (DU145 and LNCap). Moreover, the protein kinase RNA-like endoplasmic reticulum kinase/Nrf2/Glo1 pathway was greatly inhibited by NaB, thereby accumulating MGO-derived adduct hydroimidazolone (MG-H1). In response to a high amount of MGO, the expression of Nrf2 and Glo1 was attenuated, coinciding with an increased cellular death. NaB also markedly inhibited the Janus kinase 2 (JAK2)/Signal transducer and activator of transcription 3 (Stat3) pathway. Conversely, co­treatment with Colivelin, a Stat3 activator, significantly reversed the effects of NaB on Glo1 expression, MG-H1 production, and the cell migration and viability. As expected, overexpression of Stat3 or Glo1 reduced NaB­induced cell death. The activation of calcium/calmodulin dependent protein kinase II gamma and reactive oxygen species production also contributed to the anticancer effect of NaB. The present study, for the first time, demonstrated that NaB greatly increases MGO production through suppression of the JAK2/Stat3/Nrf2/Glo1 pathway in DU145 cells, a cell line mimicking castration­resistant PCa (CRPC), suggesting that NaB may be a potential agent for PCa therapy.


Assuntos
Neoplasias de Próstata Resistentes à Castração , Humanos , Masculino , Ácido Butírico/farmacologia , Janus Quinase 2/metabolismo , Óxido de Magnésio/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Aldeído Pirúvico/metabolismo , Fator de Transcrição STAT3/metabolismo
6.
Molecules ; 29(7)2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38611866

RESUMO

α-Dicarbonyls are significant degradation products resulting from the Maillard reaction during food processing. Their presence in foods can indicate the extent of heat exposure, processing treatments, and storage conditions. Moreover, they may be useful in providing insights into the potential antibacterial and antioxidant activity of U.S. honey. Despite their importance, the occurrence of α-dicarbonyls in honey produced in the United States has not been extensively studied. This study aims to assess the concentrations of α-dicarbonyls in honey samples from different regions across the United States. The identification and quantification of α-dicarbonyls were conducted using reverse-phase liquid chromatography after derivatization with o-phenylenediamine (OPD) and detected using ultraviolet (UV) and mass spectrometry methods. This study investigated the effects of pH, color, and derivatization reagent on the presence of α-dicarbonyls in honey. The quantification method was validated by estimating the linearity, precision, recovery, method limit of detection, and quantification using known standards for GO, MGO, and 3-DG, respectively. Three major OPD-derivatized α-dicarbonyls including methylglyoxal (MGO), glyoxal (GO), and 3-deoxyglucosone (3-DG), were quantified in all the honey samples. 3-Deoxyglucosone (3-DG) was identified as the predominant α-dicarbonyl in all the U.S. honey samples, with concentrations ranging from 10.80 to 50.24 mg/kg. The total α-dicarbonyl content ranged from 16.81 to 55.74 mg/kg, with the highest concentration measured for Southern California honey. Our results showed no significant correlation between the total α-dicarbonyl content and the measured pH solutions. Similarly, we found that lower amounts of the OPD reagent are optimal for efficient derivatization of MGO, GO, and 3-DG in honey. Our results also indicated that darker types of honey may contain higher α-dicarbonyl content compared with lighter ones. The method validation results yielded excellent recovery rates for 3-DG (82.5%), MGO (75.8%), and GO (67.0%). The method demonstrated high linearity with a limit of detection (LOD) and limit of quantitation (LOQ) ranging from 0.0015 to 0.002 mg/kg and 0.005 to 0.008 mg/kg, respectively. Our results provide insights into the occurrence and concentrations of α-dicarbonyl compounds in U.S. honey varieties, offering valuable information on their quality and susceptibility to thermal processing effects.


Assuntos
Mel , Fenilenodiaminas , Óxido de Magnésio , Glioxal , Aldeído Pirúvico
7.
Int J Mol Sci ; 25(7)2024 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-38612389

RESUMO

Alkaline earth metal oxide (MgO, CaO, SrO) catalysts supported on BEA zeolite were prepared by a wet impregnation method and tested in the transesterification reaction of rapeseed oil with methanol towards the formation of biodiesel (FAMEs-fatty acid methyl esters). To assess the influence of the SiO2/Al2O3 ratio on the catalytic activity in the tested reaction, a BEA zeolite carrier material with different Si/Al ratios was used. The prepared catalysts were tested in the transesterification reaction at temperatures of 180 °C and 220 °C using a molar ratio of methanol/oil reagents of 9:1. The transesterification process was carried out for 2 h with the catalyst mass of 0.5 g. The oil conversion value and efficiency towards FAME formation were determined using the HPLC technique. The physicochemical properties of the catalysts were determined using the following research techniques: CO2-TPD, XRD, BET, FTIR, and SEM-EDS. The results of the catalytic activity showed that higher activity in the tested process was confirmed for the catalysts supported on the BEA zeolite characterized by the highest silica/alumina ratio for the reaction carried out at a temperature of 220 °C. The most active zeolite catalyst was the 10% CaO/BEA system (Si/Al = 300), which showed the highest triglyceride (TG) conversion of 90.5% and the second highest FAME yield of 94.6% in the transesterification reaction carried out at 220 °C. The high activity of this system is associated with its alkalinity, high value of the specific surface area, the size of the active phase crystallites, and its characteristic sorption properties in relation to methanol.


Assuntos
Biocombustíveis , Zeolitas , Óxido de Magnésio , Metanol , Óleo de Brassica napus , Dióxido de Silício , Ácidos Graxos , Óxidos
8.
Sci Total Environ ; 926: 172172, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38575019

RESUMO

To improve the retention and slow-release abilities of nitrogen (N) and phosphorus (P), an 82 %-purity struvite fertilizer (MAP-BC) was synthesized using magnesium-modified biochar and a solution with a 2:1 concentration ratio of NH4+ to PO43- at a pH of 8. Batch microscopic characterizations and soil column leaching experiments were conducted to study the retention and slow-release mechanisms and desorption kinetics of MAP-BC. The slow-release mechanism revealed that the dissolution rate of high-purity struvite was the dominant factor of NP slow release. The re-adsorption of NH4+ and PO43- by biochar and unconsumed MgO prolonged slow release. Mg2+ ionized by MgO could react with PO43- released from struvite to form Mg3(PO4)2. The internal biochar exhibited electrostatic attraction and pore restriction towards NH4+, while magnesium modification and nutrient loading formed a physical antioxidant barrier that ensured long-term release. The water diffusion experiment showed a higher cumulative release rate for PO43- compared to NH4+, whereas in soil column leaching, the trend was reversed, suggesting that soil's competitive adsorption facilitated the desorption of NH4+ from MAP-BC. During soil leaching, cumulative release rates of NH4+ and PO43- from chemical fertilizers were 3.55-3.62 times faster than those from MAP-BC. The dynamic test data for NH4+ and PO43- in MAP-BC fitted the Ritger-Peppas model best, predicting release periods of 163 days and 166 days, respectively. The leaching performances showed that MAP-BC reduced leaching solution volume by 5.58 % and significantly increased soil large aggregates content larger than 0.25 mm by 24.25 %. The soil nutrients retention and pH regulation by MAP-BC reduced leaching concentrations of NP. Furthermore, MAP-BC significantly enhanced plant growth, and it is more suitable as a NP source for long-term crops. Therefore, MAP-BC is expected to function as a long-term and slow-release fertilizer with the potential to minimize NP nutrient loss and replace part of quick-acting fertilizer.


Assuntos
Fertilizantes , Magnésio , Estruvita/química , Magnésio/química , Fertilizantes/análise , Óxido de Magnésio , Fósforo/química , Carvão Vegetal/química , Solo/química , Nitrogênio/análise
9.
Int J Mol Sci ; 25(8)2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38673825

RESUMO

This work is devoted to magnesium oxide (MgO) nanoparticles (NPs) for their use as additives for bone implants. Extracts from four different widely used plants, including Aloe vera, Echeveria elegans, Sansevieria trifasciata, and Sedum morganianum, were evaluated for their ability to facilitate the "green synthesis" of MgO nanoparticles. The thermal stability and decomposition behavior of the MgONPs were analyzed by thermogravimetric analysis (TGA). Structure characterization was performed by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), ultraviolet-visible spectroscopy (UV-Vis), dynamic light scattering (DLS), and Raman scattering spectroscopy (RS). Morphology was studied by scanning electron microscopy (SEM). The photocatalytic activity of MgO nanoparticles was investigated based on the degradation of methyl orange (MeO) using UV-Vis spectroscopy. Surface-enhanced Raman scattering spectroscopy (SERS) was used to monitor the adsorption of L-phenylalanine (L-Phe) on the surface of MgONPs. The calculated enhancement factor (EF) is up to 102 orders of magnitude for MgO. This is the first work showing the SERS spectra of a chemical compound immobilized on the surface of MgO nanoparticles.


Assuntos
Regeneração Óssea , Química Verde , Óxido de Magnésio , Extratos Vegetais , Análise Espectral Raman , Óxido de Magnésio/química , Química Verde/métodos , Regeneração Óssea/efeitos dos fármacos , Extratos Vegetais/química , Nanopartículas/química , Nanopartículas Metálicas/química , Difração de Raios X
10.
Int J Nanomedicine ; 19: 3143-3166, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38585472

RESUMO

Background: The ability of nanomaterials to induce osteogenic differentiation is limited, which seriously imped the repair of craniomaxillofacial bone defect. Magnetic graphene oxide (MGO) nanocomposites with the excellent physicochemical properties have great potential in bone tissue engineering. In this study, we aim to explore the craniomaxillofacial bone defect repairment effect of MGO nanocomposites and its underlying mechanism. Methods: The biocompatibility of MGO nanocomposites was verified by CCK8, live/dead staining and cytoskeleton staining. The function of MGO nanocomposites induced osteogenic differentiation of BMSCs was investigated by ALP activity detection, mineralized nodules staining, detection of osteogenic genes and proteins, and immune-histochemical staining. BMSCs with or without MGO osteogenic differentiation induction were collected and subjected to high-throughput circular ribonucleic acids (circRNAs) sequencing, and then crucial circRNA circAars was screened and identified. Bioinformatics analysis, Dual-luciferase reporter assay, RNA binding protein immunoprecipitation (RIP), fluorescence in situ hybridization (FISH) and osteogenic-related examinations were used to further explore the ability of circAars to participate in MGO nanocomposites regulation of osteogenic differentiation of BMSCs and its potential mechanism. Furthermore, critical-sized calvarial defects were constructed and were performed to verify the osteogenic differentiation induction effects and its potential mechanism induced by MGO nanocomposites. Results: We verify the good biocompatibility and osteogenic differentiation improvement effects of BMSCs mediated by MGO nanocomposites. Furthermore, a new circRNA-circAars, we find and identify, is obviously upregulated in BMSCs mediated by MGO nanocomposites. Silencing circAars could significantly decrease the osteogenic ability of MGO nanocomposites. The underlying mechanism involved circAars sponging miR-128-3p to regulate the expression of SMAD5, which played an important role in the repair craniomaxillofacial bone defects mediated by MGO nanocomposites. Conclusion: We found that MGO nanocomposites regulated osteogenic differentiation of BMSCs via the circAars/miR-128-3p/SMAD5 pathway, which provided a feasible and effective strategy for the treatment of craniomaxillofacial bone defects.


Assuntos
Grafite , MicroRNAs , Nanocompostos , MicroRNAs/genética , Osteogênese/genética , RNA Circular , Hibridização in Situ Fluorescente , Óxido de Magnésio , Células Cultivadas , Regeneração Óssea , Fenômenos Magnéticos , Diferenciação Celular
11.
Int J Biol Macromol ; 266(Pt 1): 130995, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38521323

RESUMO

Critical-size bone defects are one of the main challenges in bone tissue regeneration that determines the need to use angiogenic and osteogenic agents. Rosuvastatin (RSV) is a class of cholesterol-lowering drugs with osteogenic potential. Magnesium oxide (MgO) is an angiogenesis component affecting apatite formation. This study aims to evaluate 3D-printed Polycaprolactone/ß-tricalcium phosphate/nano-hydroxyapatite/ MgO (PCL/ß-TCP/nHA/MgO) scaffolds as a carrier for MgO and RSV in bone regeneration. For this purpose, PCL/ß-TCP/nHA/MgO scaffolds were fabricated with a 3D-printing method and coated with gelatin and RSV. The biocompatibility and osteogenicity of scaffolds were examined with MTT, ALP, and Alizarin red staining. Finally, the scaffolds were implanted in a bone defect of rat's calvaria, and tissue regeneration was investigated after 3 months. Our results showed that the simultaneous presence of RSV and MgO improved biocompatibility, wettability, degradation rate, and ALP activity but decreased mechanical strength. PCL/ß-TCP/nHA/MgO/gelatin-RSV scaffolds produced sustained release of MgO and RSV within 30 days. CT images showed that PCL/ß-TCP/nHA/MgO/gelatin-RSV scaffolds filled approximately 86.83 + 4.9 % of the defects within 3 months and improved angiogenesis, woven bone, and osteogenic genes expression. These results indicate the potential of PCL/ß-TCP/nHA/MgO/gelatin-RSV scaffolds as a promising tool for bone regeneration and clinical trials.


Assuntos
Regeneração Óssea , Gelatina , Óxido de Magnésio , Osteogênese , Impressão Tridimensional , Rosuvastatina Cálcica , Alicerces Teciduais , Regeneração Óssea/efeitos dos fármacos , Rosuvastatina Cálcica/farmacologia , Rosuvastatina Cálcica/química , Alicerces Teciduais/química , Gelatina/química , Animais , Ratos , Osteogênese/efeitos dos fármacos , Óxido de Magnésio/química , Óxido de Magnésio/farmacologia , Poliésteres/química , Liberação Controlada de Fármacos , Durapatita/química , Durapatita/farmacologia , Preparações de Ação Retardada/farmacologia , Fosfatos de Cálcio/química , Fosfatos de Cálcio/farmacologia , Crânio/efeitos dos fármacos , Engenharia Tecidual/métodos
12.
Environ Sci Pollut Res Int ; 31(19): 28153-28165, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38528219

RESUMO

The re-mobilization risks of potentially toxic elements (PTEs) during stabilization deserve to be considered. In this study, artificial simulation evaluation methods based on the environmental stress of freeze-thaw (F-T), acidification and variable pH were conducted to assess the long-term effectiveness of PTEs stabilized by MgO in Pb/Zn smelter contaminated soils. Among common stabilizing materials, MgO was considered as the best remediation material, since PTEs bioavailability reduced by 55.48% for As, 19.58% for Cd, 10.57% for Cu, and 26.33% for Mn, respectively. The stabilization effects of PTEs by MgO were best at the dosage of 5 wt%, but these studied PTEs would re-mobilize after 30 times F-T cycles. Acid and base buffering capacity results indicated that the basicity of contaminated soils with MgO treatment reduced under F-T action, and the leached PTEs concentrations would exceed the safety limits of surface water quality standard in China (GB3838-2002) after acidification of 2325 years. No significant changes were found in the pH-dependent patterns of PTEs before and after F-T cycles. However, after F-T cycles, the leaching concentrations of PTEs increased due to the destruction of soil microstructure and the functionality of hydration products formed by MgO, as indicated by scanning electron microscopy (SEM) coupled with energydispersive Xray spectroscopy (EDS) results. Hence, these findings would provide beneficial references for soil remediation assessments of contaminated soils under multi-environmental stress.


Assuntos
Chumbo , Óxido de Magnésio , Poluentes do Solo , Solo , Zinco , Poluentes do Solo/química , Chumbo/química , Solo/química , Óxido de Magnésio/química , Zinco/química , China , Recuperação e Remediação Ambiental/métodos
13.
Cells ; 13(5)2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38474393

RESUMO

CD40 induces pro-inflammatory responses in endothelial and Müller cells and is required for the development of diabetic retinopathy (DR). CD40 is upregulated in these cells in patients with DR. CD40 upregulation is a central feature of CD40-driven inflammatory disorders. What drives CD40 upregulation in the diabetic retina remains unknown. We examined the role of advanced glycation end products (AGEs) in CD40 upregulation in endothelial cells and Müller cells. Human endothelial cells and Müller cells were incubated with unmodified or methylglyoxal (MGO)-modified fibronectin. CD40 expression was assessed by flow cytometry. The expression of ICAM-1 and CCL2 was examined by flow cytometry or ELISA after stimulation with CD154 (CD40 ligand). The expression of carboxymethyl lysine (CML), fibronectin, and laminin as well as CD40 in endothelial and Müller cells from patients with DR was examined by confocal microscopy. Fibronectin modified by MGO upregulated CD40 in endothelial and Müller cells. CD40 upregulation was functionally relevant. MGO-modified fibronectin enhanced CD154-driven upregulation of ICAM-1 and CCL2 in endothelial and Müller cells. Increased CD40 expression in endothelial and Müller cells from patients with DR was associated with increased CML expression in fibronectin and laminin. These findings identify AGEs as inducers of CD40 upregulation in endothelial and Müller cells and enhancers of CD40-dependent pro-inflammatory responses. CD40 upregulation in these cells is associated with higher CML expression in fibronectin and laminin in patients with DR. This study revealed that CD40 and AGEs, two important drivers of DR, are interconnected.


Assuntos
Diabetes Mellitus , Retinopatia Diabética , Humanos , Retinopatia Diabética/metabolismo , Molécula 1 de Adesão Intercelular/metabolismo , Fibronectinas/metabolismo , Células Ependimogliais/metabolismo , Células Endoteliais/metabolismo , Óxido de Magnésio/metabolismo , Retina/metabolismo , Antígenos CD40/metabolismo , Ligante de CD40/metabolismo , Laminina/metabolismo , Produtos Finais de Glicação Avançada/metabolismo , Diabetes Mellitus/metabolismo
14.
Luminescence ; 39(3): e4724, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38523053

RESUMO

For white light-rendering research activities, interpretation by using colored emitting materials is an alternative approach. But there are issues in designing the white color emitting materials. Particularly, differences in thermal and decay properties of discrete red, green, and blue emitting materials led to the quest for the search of a single-phased material, able to emit primary colors for white light generation. The current study is an effort to design a simple, single-phase, and cost-effective material with the tunable emission of primary colors by a series of Mg1-xBaxAl2O4:Mn2+ nanopowders. Doping of manganese ion (Mn2+) in the presence of the larger barium cation (Ba2+) at tetrahedral-sites of the spinel magnesium aluminate (MgAl2O4) structure led to the creation of antisite defects. Doped samples were found to have lower bandgaps compared with MgAl2O4, and hybridization of 3d-orbitals of Mn2+ with O(2p), Mg(2s)/Al(2s3p) was found to be responsible for narrowing the bandgap. The distribution of cations at various sites at random results in a variety of electronic transitions between the valance band and oxygen vacancies as well as electron traps produced the antisite defects. The suggested compositions might be used in white light applications since they have three emission bands with centers at 516 nm (green), 464 nm (blue) and 622 nm (red) at an excitation wavelength of 380 nm. A detailed discussion to analyze the effects of the larger cationic radius of Ba2+ on the lattice strain, unit cell parameters, and cell volumes using X-ray diffraction analysis is presented.


Assuntos
Óxido de Alumínio , Óxido de Magnésio , Cristalografia por Raios X , Eletrônica
15.
Chemosphere ; 353: 141586, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38452980

RESUMO

Heterogeneous activation of peroxomonosulfate (PMS) has been extensively studied for the degradation of antibiotics. The cobalt ferrite spinel exhibits good activity in the PMS activation, but suffers from the disadvantage of low PMS utilization efficiency. Herein, the nanocomposites including FeS, CoS2, CoFe2O4 and Fe2O3 were synthesized by hydrothermal method and used for the first time to activate PMS for the removal of sulfamethoxazole (SMX). The nanocomposites showed superior catalytic activity in which the SMX could be completely removed at 40 min, 0.1 g L-1 nanocomposites and 0.4 mM PMS with the first order kinetic constant of 0.2739 min-1. The PMS utilization efficiency was increased by 29.4% compared to CoFe2O4. Both radicals and non-radicals contributed to the SMX degradation in which high-valent metal oxo dominated. The mechanism analysis indicated that sulfur modification, on one hand, enhanced the adsorption of nanocomposites for PMS, and promoted the redox cycles of Fe2+/Fe3+ and Co2+/Co3+ on the other hand. This study provides new way to enhance the catalytic activity and PMS utilization efficiency of spinel cobalt ferrite.


Assuntos
Óxido de Alumínio , Cobalto , Compostos Férricos , Óxido de Magnésio , Nanocompostos , Sulfametoxazol , Peróxidos
16.
Chemosphere ; 353: 141647, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38460843

RESUMO

Humification offers a promising avenue for sequestering dissolved organic carbon while facilitating environmental cleanup. In this study, CuMgFe layered double oxides (LDO) were applied as a catalyst to replace conventional enzymes, such as laccase, thereby enhancing the in vitro polyphenol-Maillard humification reaction. CuMgFe LDO was synthesized through calcination of CuMgFe layered double hydroxides (LDH) at 500 °C for 5 h. A suite of characterization methods confirmed the successful formation into mixed oxides (Cu2O, CuO, MgO, FeO, and Fe2O3) after thermal treatment. A rapid humification reaction was observed with CuMgFe LDO, occurring within a two-week span, likely due to a distinct synergy between copper and iron elements. Subsequent analyses identified that MgO in CuMgFe LDO also played a pivotal role in humification by stabilizing the pH of the reaction. In the absence of magnesium, LDO's humification activity was more pronounced in the early stages of the reaction, but it rapidly diminished as the reaction progressed. The efficiency of CuMgFe LDO was heightened at elevated temperatures (35 °C), while light conditions manifested a discernible effect, with a modest decrease in humification efficacy under indoor light exposure. CuMgFe LDO surpassed both laccase and MgFe LDH in performance, boasting a superior humification efficiency relative to its precursor, CuMgFe LDH. The catalysts' humification activity was modulated by their crystallinity and valence dynamics. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) results suggested that introducing the amino acid, glycine, expedited the CuMgFe LDO-fueled humification, enhancing the formation of C-N and C-C bonds in the resultant products. The humic-like substances derived from the catalyst-enhanced reaction displayed an elevated presence of aromatic configurations and a richer array of oxygen functional groups in comparison to a typical commercial humic material.


Assuntos
Lacase , Óxidos , Óxidos/química , Óxido de Magnésio , Substâncias Húmicas/análise , Hidróxidos/química
17.
Langmuir ; 40(12): 6077-6093, 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38466375

RESUMO

NiCo2O4 spinel composites decorated with metal oxides (Ta2O5), reduced graphene oxide (rGO), polyaminoanthraquinone (PAAQ), and layered double hydroxide hydrotalcite (HTs) were synthesized by the hydrothermal route. The synthesized composites were characterized using X-ray powder diffraction (XRD), Brunauer-Emmett-Teller (BET), high-resolution transmission electron microscopy (HR-TEM), and X-ray photoelectron spectroscopy (XPS) analyses for structural parameters such as surface area, morphology, chemical composition, etc. The production of oxygen by the water oxidation technique is the most suitable eco-friendly method, where rGO@Ta2O5/NiCo2O4 (RTNCO) showed an efficient oxygen evolution reaction (OER) performance under 1 M KOH electrolyte. Lower Tafel slope and overpotential values of 76 mV dec-1 and 315 mV, respectively, were calculated for RTNCO. The photocatalytic degradation efficiencies calculated were MB = 97.86%, RhB = 94.75%, and AP = 96% under UV light illumination within 120 min. The degraded dye solution was tested on mung bean (Vigna radiata) plants to determine the toxicity of the dye solution after 15 days, and the results showed good seed germination similar to that in water as the control. The synthesized materials exhibited better antibacterial activity against Bacillus cereus, Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. Interestingly, the toxicological effects of the degraded dyes and drug solutions were effectively studied in the Caenorhabditis elegans model. The overall results revealed that the synthesized composites are promising for electro-/photocatalytic and biological applications.


Assuntos
Óxido de Alumínio , Caenorhabditis elegans , Grafite , Óxido de Magnésio , Nanocompostos , Animais , Água , Nanocompostos/química , Oxigênio
18.
Cancer Treat Rev ; 125: 102704, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38452708

RESUMO

BACKGROUND: Cancer-related pain often requires opioid treatment with opioid-induced constipation (OIC) as its most frequent gastrointestinal side-effect. Both for prevention and treatment of OIC osmotic (e.g. polyethylene glycol) and stimulant (e.g. bisacodyl) laxatives are widely used. Newer drugs such as the peripherally acting µ-opioid receptor antagonists (PAMORAs) and naloxone in a fixed combination with oxycodone have become available for the management of OIC. This systematic review and meta-analysis aims to give an overview of the scientific evidence on pharmacological strategies for the prevention and treatment of OIC in cancer patients. METHODS: A systematic search in PubMed, Embase, Web of Science and the Cochrane Library was completed from inception up to 22 October 2022. Randomized and non-randomized studies were systematically selected. Bowel function and adverse drug events were assessed. RESULTS: Twenty trials (prevention: five RCTs and three cohort studies; treatment: ten RCTs and two comparative cohort studies) were included in the review. Regarding the prevention of OIC, three RCTs compared laxatives with other laxatives, finding no clear differences in effectivity of the laxatives used. One cohort study showed a significant benefit of magnesium oxide compared with no laxative. One RCT found a significant benefit for the PAMORA naldemedine compared with magnesium oxide. Preventive use of oxycodone/naloxone did not show a significant difference in two out of three other studies compared to oxycodone or fentanyl. A meta-analysis was not possible. Regarding the treatment of OIC, two RCTs compared laxatives, of which one RCT found that polyethylene glycol was significantly more effective than sennosides. Seven studies compared an opioid antagonist (naloxone, methylnaltrexone or naldemedine) with placebo and three studies compared different dosages of opioid antagonists. These studies with opioid antagonists were used for the meta-analysis. Oxycodone/naloxone showed a significant improvement in Bowel Function Index compared to oxycodone with laxatives (MD -13.68; 95 % CI -18.38 to -8.98; I2 = 58 %). Adverse drug event rates were similar amongst both groups, except for nausea in favour of oxycodone/naloxone (RR 0.51; 95 % CI 0.31-0.83; I2 = 0 %). Naldemedine (NAL) and methylnaltrexone (MNTX) demonstrated significantly higher response rates compared to placebo (NAL: RR 2.07, 95 % CI 1.64-2.61, I2 = 0 %; MNTX: RR 3.83, 95 % CI 2.81-5.22, I2 = 0 %). With regard to adverse events, abdominal pain was more present in treatment with methylnaltrexone and diarrhea was significantly more present in treatment with naldemedine. Different dosages of methylnaltrexone were not significantly different with regard to both efficacy and adverse drug event rates. CONCLUSIONS: Magnesium oxide and naldemedine are most likely effective for prevention of OIC in cancer patients. Naloxone in a fixed combination with oxycodone, naldemedine and methylnaltrexone effectively treat OIC in cancer patients with acceptable adverse events. However, their effect has not been compared to standard (osmotic and stimulant) laxatives. More studies comparing standard laxatives with each other and with opioid antagonists are necessary before recommendations for clinical practice can be made.


Assuntos
Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Naltrexona/análogos & derivados , Neoplasias , Constipação Induzida por Opioides , Humanos , Laxantes/uso terapêutico , Analgésicos Opioides/efeitos adversos , Antagonistas de Entorpecentes/uso terapêutico , Antagonistas de Entorpecentes/efeitos adversos , Constipação Intestinal/induzido quimicamente , Constipação Intestinal/tratamento farmacológico , Constipação Intestinal/prevenção & controle , Oxicodona/uso terapêutico , Oxicodona/efeitos adversos , Constipação Induzida por Opioides/tratamento farmacológico , Constipação Induzida por Opioides/etiologia , Óxido de Magnésio/efeitos adversos , Estudos de Coortes , Naloxona/uso terapêutico , Naloxona/efeitos adversos , Polietilenoglicóis/uso terapêutico , Neoplasias/tratamento farmacológico , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/tratamento farmacológico , Compostos de Amônio Quaternário
19.
J Dent ; 144: 104952, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38508442

RESUMO

OBJECTIVES: Evaluation of the two-body wear of lithium-silicate ceramics against different antagonists compared to a direct resin composite and human teeth. METHODS: Initial LiSi Block [LISI], IPS e.max CAD [EMA], and CEREC Tessera [TESE] were investigated and compared with direct resin composite [FILL] and human teeth [tooth]. As antagonists were used: steatite, ceramic, and human enamel. The control group tooth was only tested with enamel antagonist. The combinations underwent thermomechanical aging using a chewing simulator. Material losses were calculated using GOM-analysis software. Kolmogorov-Smirnov test, Kruskal-Wallis H, Mann-Whitney-U-test with Bonferroni correction and Spearman-rho correlation were calculated. A fractographic analysis was performed. RESULTS: Within TESE, enamel antagonists led to lower restoration losses than steatite and ceramic antagonists. Within FILL, enamel and steatite antagonists caused lower material losses compared to ceramic antagonists. Against steatite antagonists, LISI showed lowest material losses. Against ceramic antagonists, the use of LISI led to lower material losses compared to FILL. Against tooth antagonists, TESE showed lower material losses than tooth and FILL and LISI lower than FILL. Within LISI, steatite antagonists showed lower material losses on the antagonist than ceramic. Within EMA, steatite antagonists showed higher material losses than ceramic ones. Within ceramic antagonists, LISI restoration material showed lower material losses than FILL and EMA. CONCLUSIONS: Regardless of the antagonist material, the material losses of LISI and EMA were comparable. However, the abrasion resistance of LISI tended to be higher than EMA. CLINICAL SIGNIFICANCE: LISI is a fully crystallized lithium-silicate ceramic and no longer needs to be processed after milling. In addition, the abrasion resistance is very good, regardless of the antagonist material chosen.


Assuntos
Cerâmica , Resinas Compostas , Esmalte Dentário , Porcelana Dentária , Óxido de Magnésio , Teste de Materiais , Dióxido de Silício , Humanos , Resinas Compostas/química , Porcelana Dentária/química , Esmalte Dentário/efeitos dos fármacos , Cerâmica/química , Materiais Dentários/química , Silicatos/química , Propriedades de Superfície , Desgaste de Restauração Dentária , Desenho Assistido por Computador , Lítio
20.
J Agric Food Chem ; 72(11): 5828-5841, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38442256

RESUMO

α-Dicarbonyl compounds, such as glyoxal (GO) and methylglyoxal (MGO), are a series of chemical hazards that exist in vivo and in vitro, posing a threat to human health. We aimed to explore the scavenging effects on GO/MGO by synephrine (SYN) alone or in combination with neohesperidin (NEO). First, through LC-MS/MS, we confirmed that both SYN and NEO could effectively remove GO and form GO adducts, while NEO could also clear MGO by forming MGO adducts, and its ability to clear MGO was stronger than that of GO. Second, a synergistic inhibitory effect on GO was found when SYN and NEO were used in combination by using the Chou-Talalay method; on the other hand, SYN could promote NEO to clear more MGO, although SYN could not capture MGO. Third, after synthesizing four GO/MGO-adducts (SYN-GO-1, SYN-GO-3, NEO-GO-7, and NEO-MGO-2) and identifying their structure through NMR, strict correlations between the GO/MGO-adducts and the GO/MGO-clearance rate were found when using SYN and NEO alone or in combination. Furthermore, it was inferred that the synergistic effect between SYN and NEO stems from their mutual promotion in capturing more GO by the quantitative analysis of the adducts in the combined model. Finally, a study was conducted on flowers of Citrus aurantium L. var. amara Engl. (FCAVA, an edible tea) rich in SYN and NEO, which could serve as an effective GO and MGO scavenger in the presence of both GO and MGO. Therefore, our study provided well-defined evidence that SYN and NEO, alone or in combination, could efficiently scavenge GO/MGO at high temperatures, whether in the pure form or located in FCAVA.


Assuntos
Glioxal , Hesperidina/análogos & derivados , Aldeído Pirúvico , Humanos , Aldeído Pirúvico/química , Glioxal/química , Sinefrina , Cromatografia Líquida , Óxido de Magnésio , Temperatura , Espectrometria de Massas em Tandem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...