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1.
Environ Sci Pollut Res Int ; 31(29): 42330-42341, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38866933

RESUMO

A novel mesoporous magnetic biochar (MBC) was prepared, using a randomly growing plant, i.e., common reed, as an exporter of carbon, and applied for removal of methylene blue (MB) from aqueous solutions. The prepared sorbent was characterized by nitrogen adsorption/desorption isotherm, saturation magnetization, pH of point of zero charges (pHPZC), Fourier-transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). The obtained MBC has a specific surface area of 94.2 m2 g-1 and a pore radius of 4.1 nm, a pore volume of 0.252 cm3 g-1, a saturation magnetization of 0.786 emu g-1, and a pHPZC of 6.2. Batch adsorption experiments were used to study the impact of the physicochemical factors involved in the adsorption process. The findings revealed that MB removal by MBC was achieved optimally at pH 8.0, sorbent dosage of 1.0 g L-1, and contact time of 30 min. At these conditions, the maximum adsorption was 353.4 mg g-1. Furthermore, the adsorption isotherm indicated that the Langmuir pattern matched well with the experimental data, compared to the Freindlich model. The ∆G was - 6.7, - 7.1, and - 7.5 kJ mol-1, at 298, 308, and 318 K, respectively, indicating a spontaneous process. The values of ∆H and ∆S were 5.71 kJ mol-1 and 41.6 J mol-1 K-1, respectively, suggesting endothermic and the interaction between MB and MBC is van der Waals type. The absorbent was regenerated and reused for four cycles after elution with 0.1 mol L-1 of HCl. This study concluded that the magnetic biochar generated from common reed has tremendous promise in the practical use of removing MB from wastewater.


Assuntos
Carvão Vegetal , Azul de Metileno , Poaceae , Poluentes Químicos da Água , Azul de Metileno/química , Carvão Vegetal/química , Adsorção , Poluentes Químicos da Água/química , Espectroscopia de Infravermelho com Transformada de Fourier , Purificação da Água/métodos , Porosidade , Concentração de Íons de Hidrogênio , Cinética
2.
Carbohydr Polym ; 341: 122359, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-38876709

RESUMO

To address escalating environmental and sustainability concerns of petroleum-based superplasticizers (SPs), this work aims to develop sustainable and eco-friendly starch-based SPs using gamma radiation for maintaining the desired workability of geopolymeric pastes. Specifically, two green SPs were prepared from starch via radiation-induced grafting of two sulfonic group-bearing monomers, namely 2-acrylamido-2-methylpropane sulfonic acid (AMPS) and 4-styrene sulfonic acid sodium salt (Na4SS). The grafting reaction was improved by initial modification of starch with glycidyl methacrylate to insert vinyl groups into the starch backbone. The modified starch samples were characterized by a variety of analytical techniques such as FTIR, 1H NMR, EDX, SLS, and viscometry. The prepared SPs exhibited high stability in aqueous 5 % NaOH. The effect of the prepared SPs on the fresh properties of GGBFS/MK geopolymer was studied using the mini slump test, zeta potential, adsorption capacity, and setting time. They significantly improved the paste flowability and dispersion compared to the control. Notably, the aromatic Na4SS-grafted starch displayed a comparable enhancement to the commercial PNS, while outperforming the aliphatic AMPS-grafted sample. This emphasizes the potential of these green SPs to address the challenges posed by the petroleum-based SPs and maximize the benefit of using starch as a green renewable resource.

3.
Pathol Res Pract ; 256: 155237, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38492358

RESUMO

A serious consequence of diabetes mellitus, diabetic nephropathy (DN) which causes gradual damage to the kidneys. Dietary changes, blood pressure control, glucose control, and hyperlipidemia are all important components of DN management. New research, however, points to microRNAs (miRNAs) as having a pivotal role in DN pathogenesis. Miniature non-coding RNA molecules such as miRNAs control gene expression and impact several biological processes. The canonical and non-canonical routes of miRNA biogenesis are discussed in this article. In addition, several important signaling pathways are examined in the study of miRNA regulation in DN. A deeper knowledge of these regulatory mechanisms would allow for a better understanding of the molecular basis of DN and the development of innovative therapeutic strategies. Finally, miRNAs show tremendous potential as DN diagnostic biomarkers and treatment targets, opening up promising avenues for further study and potential clinical use.


Assuntos
Diabetes Mellitus , Nefropatias Diabéticas , MicroRNAs , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Nefropatias Diabéticas/metabolismo , Rim/metabolismo , Transdução de Sinais/genética
4.
Sci Rep ; 13(1): 4611, 2023 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-36944693

RESUMO

Sodium hydroxide (NaOH) as an alkaline activator presents a vital limitation in the mass production of alkali-activated binders due to its severe effect on users' safety. In this study, safe and sustainable one-part alkali-activated slag mixes (OP-AAS) were prepared through an efficient microwave sintering for a mixture of active amorphous ground granulated blast furnace slag (GGBFS) and sodium hydroxide powder (NaOH). Different microwave-sintered powders were prepared using microwave energy of power 900 W for the mixture at different treatment periods (10, 20, and 30 min). Fresh and hardened properties of different OP-AAS mixes were studied. Moreover, the phase composition and microstructure were investigated using X-ray diffraction (XRD) analysis and scanning electron microscope (SEM). Cytotoxicity/viability testing was performed to evaluate the cell death induced by the developed materials to measure their safety for the user. According to compressive strength, cytotoxicity/viability analysis, environmental impact and cost calculation of developed OP-AAS, it is concluded that employing microwave sintering for a short duration is sufficient to produce safe binding materials with adequate mechanical properties suitable for commercial applications in the construction sector.

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