Search Results (9,906)

Herein we report the synthesis of three novel sulfonamide derivatives of trimetazidine—medication primarily used to treat angina pectoris. The new compounds have been fully characterized with their melting point, ¹H- and ¹³C-NMR, UV, and mass spectrometry. The collected data confirm the successful synthesis and structural integrity of the new molecules. Full article

Among polymer wastes, poly(ethylene terephthalate) (PET) is the most important commercial thermoplastic polyester. Less than 30% of total PET production is recycled into new products. Therefore, large amounts of waste PET need to be recycled. We describe a feasible approach for the direct application of the glycolysis products of PET (GP-PET), without further purification, for the synthesis of value-added products. It was established that GP-PET is valorized via phosphorylation with phenylphosphonic dichloride (PPD), as well as with trimethyl phosphate (TMP). When PPD is used, a condensation reaction takes place with the evolution of hydrogen chloride. During the interaction between GP-PET and TMP, the following reactions take place simultaneously: a transesterification with the participation of the hydroxyl group of GP-PET and the methoxy group of TMP and an exchange reaction between the ester group of GP-PET and the methyl ester group of TMP. The occurrence of the exchange reaction was confirmed by ¹H, ³¹P, ¹³C NMR, and GPC analysis. Thermogravimetric analysis (TGA) revealed that the percentage of a carbon residual (CR) implies the possibility of using the end products as flame retardant (FR) additives, especially for polyurethanes as well as thermal stabilizers of polymer materials or Li-ion cells. Full article

The growing consumer demand for natural and eco-friendly food products motivates the development and evaluation of new and natural inputs for the food industry. So, this work explores the potential of grape pomace (GP) from winemaking, a food production residue, to obtain an anthocyanin-rich, ready-to-use extract with antioxidant activity that can confer improved color-rich gummy candies. The anthocyanins’ chemical nature and the predictive COSMO-SAC model was considered for screening the best natural eutectic mixture for anthocyanin extraction. The eutectic mixtures composed of choline chloride as a hydrogen bond acceptor and acetic and citric acids as hydrogen bond donors were selected as solvents. The extraction was performed using a high-shear disperser (Ultra-Turrax^®) at 45 °C and was stirred at 5000 rpm for 10 min. The extracts presented high total anthocyanin content (TAC), up to 60 µg equivalent of cyaniding-3-glucoside/g of dry GP, and high antioxidant activity as determined by DPPH and FRAP assays. The phenolic profile was also determined by high-performance liquid chromatography (HPLC) and the results corroborated with the antioxidant activity of the extracts. The results also demonstrate that eutectic mixtures enhance the extraction efficiency of anthocyanins and improve their stability, making them suitable for incorporation into functional food products such as gummies, acting as natural colorants. Full article

This article investigates the activation of surface groups of poly(ethylene terephthalate) (PET) fibers in woven fabric by hydrolysis and their functionalization with chitosan. Two types of hydrolysis were performed—alkaline and enzymatic. The alkaline hydrolysis was performed in a more sustainable process at reduced temperature and time (80 °C, 10 min) with the addition of the cationic surfactant hexadecyltrimethylammonium chloride as an accelerator. The enzymatic hydrolysis was performed using Amano Lipase A from Aspergillus niger (2 g/L enzyme, 60 °C, 60 min, pH 9). The surface of the PET fabric was functionalized with the homogenized gel of biopolymer chitosan using a pad–dry–cure process. The durability of functionalization was tested after the first and tenth washing cycle of a modified industrial washing process according to ISO 15797:2017, in which the temperature was lowered from 75 °C to 50 °C, and ε-(phthalimido) peroxyhexanoic acid (PAP) was used as an environmentally friendly agent for chemical bleaching and disinfection. The influence of the above treatments was analyzed by weight loss, tensile properties, horizontal wicking, the FTIR-ATR technique, zeta potential measurement and SEM micrographs. The results indicate better hydrophilicity and effectiveness of both types of hydrolysis, but enzymatic hydrolysis is more environmentally friendly and favorable. In addition, alkaline hydrolysis led to a 20% reduction in tensile properties, while the action of the enzyme resulted in a change of only 2%. The presence of chitosan on polyester fibers after repeated washing was confirmed on both fabrics by zeta potential and SEM micrographs. However, functionalization with chitosan on the enzymatically bioactivated surface showed better durability after 10 washing cycles than the alkaline-hydrolyzed one. The antibacterial activity of such a bio-innovative modified PET fabric is kept after the first and tenth washing cycles. In addition, applied processes can be easily introduced to any textile factory. Full article

This study aims to compare the effects of three calcium compounds on the workability, setting time and mechanical properties of red mud (RM)–blast furnace slag (BFS)-based geopolymers. The crystalline phase, hydration process and microstructure of RM-BFS-based geopolymers were characterized by X-ray diffraction (XRD), heat evolution, X-ray photoelectron spectroscopy (XPS), and scanning electron microscope (SEM) tests. The results showed that an appropriate amount of calcium compounds can improve the flowability and compressive strength of the geopolymers, but the excessiveness causes a decrease in strength due to rapid hardening. Other than calcium carbonate, both calcium oxide and calcium chloride played important roles in accelerating the setting times of RM-BFS-based geopolymers. The acceleration in the setting times of geopolymers could be attributed to the calcium hydroxide produced by the dissolution of the calcium compounds, which also provides nucleation sites for the geopolymerization reaction. This study gives new insights into the effect of calcium on the setting times and mechanical properties of geopolymers in the geopolymerization process. Full article

Retinoids are known to improve the condition of the skin. Transepithelial transport of sodium and chloride ions is important for proper skin function. So far, the effect of applying vitamin A preparations to the skin on ion transport has not been evaluated. In the study, electrophysiological parameters, including transepithelial electric potential (PD) and transepithelial resistance (R), of rabbit skin specimens after 24 h exposure to retinol ointment (800 mass units/g) were measured in a modified Ussing chamber. The R of the fragments incubated with retinol was significantly different than that of the control skin samples incubated in iso-osmotic Ringer solution. For the controls, the PD values were negative, whereas the retinol-treated specimens revealed positive PD values. Mechanical–chemical stimulation with the use of inhibitors of the transport of sodium (amiloride) or chloride (bumetanide) ions revealed specific changes in the maximal and minimal PD values measured for the retinol-treated samples. Retinol was shown to slightly modify the transport pathways of sodium and chloride ions. In particular, an intensification of the chloride ion secretion from keratinocytes was observed. The proposed action may contribute to deep hydration and increase skin tightness, limiting the action of other substances on its surface. Full article

Melanoma, the most aggressive form of skin cancer, presents a major clinical challenge due to its tendency to metastasize and recalcitrance to traditional therapies. Despite advances in surgery, chemotherapy, and radiotherapy, the outlook for advanced melanoma remains bleak, reinforcing the urgent need for more effective treatments. Photodynamic therapy (PDT) has emerged as a promising alternative, leading to targeted tumor destruction with minimal harm to surrounding tissues. In this study, the direct and abscopal antitumor effects of PDT in a bilateral murine melanoma model were evaluated. Although only one of the two tumors was treated, effects were observed in both. Our findings revealed significant changes in systemic inflammation and alterations in CD4⁺ and CD8⁺ T cell populations in treated groups, as evidenced by blood analyses and flow cytometry. High-throughput RNA sequencing (RNA-Seq) further unveiled shifts in gene expression profiles in both treated and untreated tumors. This research sheds light on the novel antitumor and abscopal effects of nanoemulsion of aluminum chloride phthalocyanine (AlPcNE)-mediated PDT in melanoma, highlighting the potential of different PDT protocols to modulate immune responses and to achieve more effective and targeted cancer treatments. Full article

In the present work, the corrosion properties and the surface chemistry of a graphene oxide-coated AZ91D alloy were investigated. The coatings were deposited on the substrate specimens by immersion in solutions with GO concentrations of 0.05% and 0.1% (m/v). An intermediate silane layer was firstly obtained to improve adhesion between the GO films and the AZ91D substrate. The electrochemical behavior of the coated specimens was assessed using electrochemical impedance spectroscopy and potentiodynamic polarization curves in 3.5 wt.% NaCl solution. The surface chemistry was assessed using X-ray photoelectron spectroscopy (XPS). The GO films consisted of a mixture of carbon-based bonds (C-C, C-OH, C=O, and O-C=O). The surface morphology of the coated specimens was examined using scanning electron microscopy. The results revealed that the compactness of the GO films was dependent on the deposition conditions. The corrosion resistance was affected by the surface morphology. Full article

The present study examines the water quality in the Quaternary Mio-Plio-Quaternary aquifer of the mining basin of Gafsa using a hydrochemical approach and multivariate statistical methods, to assess groundwater mineralization processes. Results from the analysis of groundwater quality collected during the winter (January 2020) and summer (June 2021) seasons reveal a pronounced stability in geochemical parameters, emphasizing a noteworthy consistency in water composition between the two seasons, with the dominance of the Na-Ca-Mg-SO4-Cl facies, in addition to the fact that all year round these concentrations are beyond their respective WHO limits. Despite the intensive extractive and transformation phosphate industry, the prolonged interaction of water with geological formations is the primary factor controlling their high mineralization. This results from the dissolution of carbonates (calcite, dolomite), gypsum, and halite. The results of the PCA represent two correlation classes. Class 1 comprises major elements sulfate, chloride, sodium, magnesium, and calcium strongly correlated with electrical conductivity (EC) and total dissolved solids (TDS). This correlation is indicative of the water mineralization process. Class 2 includes major elements nitrate and potassium weakly correlated with (TDS) and (EC) As regards heavy metals, their concentrations fall consistently below their respective potability standards established by the WHO across all water sampling points. Meanwhile, fluoride (F-) concentrations exhibited values ranging from (1.6 mg·L⁻¹ to 2.9 mg·L⁻¹) in the winter of January 2020 and (1 to 2.9 mg·L⁻¹) in the summer of June 2021, surpassing its WHO limit (1.5 mg·L⁻¹) in almost all water samples. These findings allow us to conclude that the high mineralization of these waters is acquired due to the dissolution of carbonates (calcite, dolomite), gypsum, and halite due to their prolonged interaction with the geological formations. The deterioration of groundwater quality in the Gafsa mining basin associated with phosphate extraction and processing activities appears to be primarily due to the intensive exploitation of deep-water resources. Full article

This study explores the use of secondary gold tailings (SGTs) in concrete production to solve sand sustainability issues. This approach addresses waste issues and presents a sustainable material alternative to conventional sand, investigating different SGT proportions (ranging from 0% to 100%) to replace fine aggregate in structural concrete. This study examined the fresh, mechanical, and durability properties of concrete containing SGTs. Incorporating SGTs reduced the concrete’s workability, but up to a 75% replacement level resulted in a high fresh concrete density compared with the reference concrete. The results indicated that up to 25% replacement level increased the compressive strength and up to 50% replacement level improved the splitting tensile strength compared with reference concrete. However, all concretes containing SGTs exhibited satisfactory strengths. The statistical analysis confirmed the significant influence of SGTs on concrete strength. In addition, the durability results of the concrete demonstrated good resistance to oxygen, water, and chloride penetration, indicating good concrete quality. SGTs are recommended as a substitute for crusher sand to reduce production costs, conserve natural resources, and promote a sustainable and greener environment. Full article

In this study, nine concrete short columns and nine UHPC (ultra-high-performance concrete) short columns were produced, and an accelerated corrosion test method was used to compare and analyze the cracking phenomena and reinforcement corrosion after different durations of electrical current application. The analysis revealed that the corrosion rate of the UHPC specimens was approximately half of that of the concrete specimens, demonstrating excellent corrosion resistance. Although the corrosion rate of the UHPC specimen was lower, the length of the internal steel reinforcement decreased more significantly under prolonged electrification. For example, after 38 days of accelerated corrosion, the internal steel reinforcement in the ordinary concrete specimen measured 48 mm in length, while in the UHPC specimen, it measured only 43 mm. It was also found that the corrosion rates of both the concrete and UHPC specimens were significantly lower than the theoretical corrosion rate. This discrepancy is attributed to the fact that Faraday’s law, used to calculate the theoretical corrosion rate, does not fully account for factors such as the thickness of the protective layer and chloride ion concentration. The actual corrosion rate of the concrete specimens was generally only 70% of the theoretical value, while the UHPC specimens showed a corrosion rate which was only 40% of the theoretical value. Full article

One of the challenges of our time is replacing the existing fossil fuel-based economy with a green one in the framework of developing a sustainable society. The biological synthesis of nanoparticles from plant extracts is currently under study for developing environmentally compatible nanoparticle synthesis and avoiding adverse effects. The environmental impacts of emissions, energy requirements, and energy losses are calculated to comparatively evaluate the effects of the traditional process, in addition to any new one, in obtaining TiO₂ nanoparticles from the life cycle point of view. The two methods are syntheses via green chemistry (using an aqueous extract of Cymbopogon citratus) and via the chloride route, which are some of the most used methods for the synthesis of TiO₂ nanoparticles owing to them having the most advanced production processes. The life cycle analysis was carried out using OpenLCA software, which showed that the production of chemically synthesized TiO₂ contributes to greenhouse gas emissions and respiratory effects caused by inorganic substances. On the other hand, green synthesis contributes to reductions in toxicity and greenhouse gas emissions. Full article

It is imperative to eliminate heavy metals and pharmaceutical residual pollutants from wastewater to reduce their detrimental effects on the environment. In this work, natural zeolite and a 2-amino terephthalic acid-based multi-metallic organic framework were used to create a new composite that can be utilized as an adsorbent for cadmium and safinamide. The adsorption study was examined in a variety of settings (pH, adsorbent dosage, pollutant concentration, and time). Moreover, Zeta potential, BET, SEM, FTIR, XRD, and SEM measurements were used to characterize the adsorbents. The adsorption process was confirmed using FTIR, XRD, and SEM analysis. Various nonlinear adsorption isotherm models were applied to adsorption results. The results showed a significantly better adsorption ability for safinamide and cadmium using zeolite/MOF compared to zeolite. Adsorption kinetics were represented by five models: pseudo first-order, pseudo second-order, intraparticle diffusion, mixed first- and second-order, and the Avrami model. Regarding both adsorbent substances, safinamide adsorption was best represented by the intraparticle diffusion model. In contrast, the pseudo second-order and intraparticle diffusion models for zeolite and zeolite/MOF, respectively, better fit the experimental results in the case of cadmium adsorption. The thermodynamic parameters ΔH°, ΔS°, and ΔG° were investigated through temperature tests carried out at 25, 35, 45, and 55 °C. Exothermic and spontaneous adsorption processes were demonstrated by the computed values. The study of adsorbent regeneration involved the use of several chemical solvents. The DMSO solvent was shown to have the highest adsorbent regeneration method efficiency at 63%. Safinamide elimination was lessened by organic interfering species like cefixime and humic acid compared to inorganic species like chloride, sulphate, and nitrate, most likely as a result of intense competition for the few available active sites. Using zeolite/MOF nanocomposite, the percentage of safinamide removed from spiked real water samples (tap water, Nile River water, and groundwater samples) was 48.80%, 64.30%, and 44.44%, respectively. Based on cytotoxicity results, the highest percentages of cell viability for zeolite and zeolite/MOF at 24 h were 83% and 81%, respectively, in comparison to untreated controls. According to these results, zeolite and zeolite/MOF composites can be used as effective adsorbents for these pollutants in wastewater. Full article

In this paper, a lab-scale reactor designed to simulate the operations of the North Water Saline Wastewater Treatment Plant (SWWTP) located in Delfzijl, The Netherlands, was constructed and assessed. Unlike conventional municipal wastewater treatment facilities, this industrial plant deals with wastewater containing stubborn chemicals that are difficult to break down, along with a high ratio of chemical oxygen demand (COD) to nitrogen and elevated sodium chloride levels. Furthermore, its treatment process diverges from standard industrial setups by employing an aerobic process preceding the anaerobic phase. The proposed lab-scale reactors were proven stable and effective in mimicking the conditions of the studied industrial SWWTP, particularly in the presence of abundant glycerol, a factor not explored in similar lab-scale models. Throughout the experiment, the removal of COD (specifically glycerol) and nitrogen were monitored, alongside changes in the microbial community within both reactors. The data enabled us to examine the proliferation of microbial populations within the sludge. The results indicated the complete removal of glycerol and ammonia from the system, with some residual nitrate detected in the effluent. The soluble COD decreased in the first reactor (R1) to approximately 50% of the influent and reduced further to less than 100 mg/L in the second reactor (R2), while nitrogen was majorly removed in the R1. By the experiment’s conclusion, Actinomycetales was identified as the dominant order in the anaerobic reactor (sometimes even exceeding 70% of the population), which is known for its utilization of glycerol as a carbon source and its tolerance to high salt concentrations in the influent. Conversely, the aerobic reactor was predominantly inhabited by the order Flavobacteriales, which correlates with ammonia concentration. Full article

The objective of the present study was to compare principal cell-specific aquaporin-2 (AQP2) abundances in urinary extracellular vesicles (uEVs) on the first postoperative day in deceased-donor kidney transplant recipients without and with acute kidney injury. We measured uEV markers (CD9 and CD63) and the abundances of proximal tubular sodium-glucose transporter 2, distal tubular sodium/chloride cotransporter, and principal cell-specific aquaporin-2 using Western blotting of urine. uEV-AQP2 levels were normalized to living donor controls. The validation cohort consisted of 82 deceased-donor kidney transplant recipients who had a median age of 50 years (IQR 43 to 57 years). A total of 32% of recipients had acute kidney injury. The median uEV-AQP2 was significantly higher in recipients with acute kidney injury compared to immediate allograft function (2.05; IQR 0.87 to 2.83; vs. 0.81; IQR 0.44 to 1.78; p < 0.01). The Youden index indicated a uEV-AQP2 threshold of 2.00. Stratifying uEV-AQP2 into quartiles showed that recipients with higher uEV-AQP2 levels had higher rates of acute kidney injury (Cochran–Armitage, p = 0.001). The discovery cohort showed elevated CD9, CD63, and uEV-AQP2 levels in urine from recipients with acute kidney injury compared to immediate allograft function. We were able to quantify the damage of principal cells after kidney transplant to predict acute kidney injury using uEV-AQP2. Full article