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The need to develop advanced wastewater treatment techniques and their use has become a priority, the main goal being the efficient removal of pollutants, especially those of organic origin. This study presents the photo-degradation of a pharmaceutical wastewater containing Kabi cytarabine, using ultraviolet (UV) radiation, and a synthesized catalyst, a composite based on bismuth and iron oxides (BFO). The size of the bandgap was determined by UV spectroscopy, having a value of 2.27 eV. The specific surface was determined using the BET method, having a value of 0.7 m2 g−1. The material studied for the photo-degradation of cytarabine presents a remarkable photo-degradation efficiency of 97.9% for an initial concentration 0f 10 mg/L cytarabine Kabi when 0.15 g of material was used, during 120 min of interaction with UV radiation at 3 cm from the irradiation source. The material withstands five photo-degradation cycles with good results. At the same time, through this study, it was possible to establish that pyrimidine derivatives could be able to combat infections caused by Escherichia coli and Candida parapsilosis.

The present paper describes the preparation and characterization of a new dinuclear ligand based on terpyridine featuring a diselenide unit. This new compound was synthesized in a two-step procedure that first involved the insertion of the diselenide moiety on a carboxylic acid and was followed by a Steglich esterification reaction between the biscarboxylic acid containing the diselenide unit and 2,6-di(pyridin-2-yl)pyridin-4-ol (tpyOH). The title compound was characterized via FT-IR, Raman, NMR (1D and 2D), and UV-Vis spectroscopies and elemental analysis. Emission properties were investigated.

Bioactive compounds extracted from plants can provide wide health benefits. However, some molecules have limited applications as pharmaceuticals due to their limited solubility, poor bioavailability, and low stability when exposed to environmental factors. Their integration in formulations that can deliver them to physiological targets while preserving their biological activity can enhance their usage in improving human health. This research provides a delivery system design to enhance the solubility, stability and to mask the bitter taste of salicin. Thus, a novel salicin-β-cyclodextrin complex was prepared and analyzed by X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, FTIR, Raman and UV-Vis spectroscopy. The analytical and computational methods provided clear and distinct evidence for inclusion of salicin within the β-cyclodextrin cavity and brought important findings for the characterization of the inclusion complex. The present study showed that salicin and β-cyclodextrin can form inclusion complexes, both in solution and in solid state, and that the inclusion of salicin in the cavity of β-cyclodextrin leads to the improvement of its solubility and stability. Thus, the study communicates both qualitative and quantitative knowledge about the preparation of a new salicin-β-cyclodextrin inclusion complex suggesting its potential applications in pharmaceutical industry and medical sciences, as formulations with better compliance for the patient, with increased bioavailability, and easier control of dosage.

In recent years, during industrial development, the expanding discharge of harmful metallic ions from different industrial wastes (such as arsenic, barium, cadmium, chromium, copper, lead, mercury, nickel, selenium, silver, or zinc) into different water bodies has caused serious concern, with one of the problematic elements being represented by selenium (Se) ions. Selenium represents an essential microelement for human life and plays a vital role in human metabolism. In the human body, this element acts as a powerful antioxidant, being able to reduce the risk of the development of some cancers. Selenium is distributed in the environment in the form of selenate (SeO42–) and selenite (SeO32–), which are the result of natural/anthropogenic activities. Experimental data proved that both forms present some toxicity. In this context, in the last decade, only several studies regarding selenium’s removal from aqueous solutions have been conducted. Therefore, in the present study, we aim to use the sol–gel synthesis method to prepare a nanocomposite adsorbent material starting from sodium fluoride, silica, and iron oxide matrices (SiO2/Fe(acac)3/NaF), and to further test it for selenite adsorption. After preparation, the adsorbent material was characterized by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). The mechanism associated with the selenium adsorption process has been established based on kinetic, thermodynamic, and equilibrium studies. Pseudo second order is the kinetic model that best describes the obtained experimental data. Also, from the intraparticle diffusion study, it was observed that with increasing temperature the value of the diffusion constant, Kdiff, also increases. Sips isotherm was found to best describe the experimental data obtained, the maximum adsorption capacity being ~6.00 mg Se(IV) per g of adsorbent material. From a thermodynamic point of view, parameters such as ΔG0, ΔH0, and ΔS0 were evaluated, proving that the process studied is a physical one.

Herein, we present the investigation of catalytical and fluorescence properties for Ni11(HPO3)8(OH)6 materials obtained through a hydrothermal approach. As part of the constant search for new materials that are both cost effective and electrocatalytically active for the oxygen evolution reaction (OER) in alkaline medium, the present study involves several graphite electrodes modified with Ni11(HPO3)8(OH)6 mixed with reduced graphene oxide (rGO) and carbon black. The experimental results obtained in 0.1 mol L–1 KOH electrolyte solution show the electrode modified with rGO, 5 mg carbon black and 1 mg nickel phosphite as displaying the highest current density. This performance can be attributed to the synergistic effect between nickel phosphite and the carbon materials. Investigation of the electrode’s OER performance in 0.1 mol L–1 KOH solution revealed a Tafel slope value of just 46 mV dec–1. By increasing the concentration to 0.5 and 1 mol L–1, this value increased as well, but there was a significant decrease in overpotential. Fluorescence properties were analyzed for the first time at the excitation length of 344 nm, and the observed strong and multiple emissions are described.

Aggressive industrial development over the last century involved different heavy metals being used, including high quantities of molybdenum, which need to be treated before discharge in industrial waters. Molybdenum’s market price and industrial applicability make its recovery a big challenge. In the present study the possibility to recover molybdenum ions from aqueous solutions by adsorption on a composite material based on silica matrix and iron oxides—SiO2FexOy—was evaluated. Tests were performed in order to determine the influence of adsorbent material dose, initial solution pH, contact time and temperature over adsorption capacity of synthesized adsorbent material. For better understanding of the adsorption process, the obtained experimental data were modelled using Langmuir, Freundlich and Sips adsorption isotherms. Based on the obtained data, it can proved that the Sips isotherm was describing with better orderliness the studied process, obtaining a maximum adsorption capacity of 10.95 mg MoO42− for each gram of material. By modelling the studied adsorption process, it was proven that the pseudo-second order model is accurately describing the adsorption process. By fitting experimental data with Weber-Morris model, it was proven that MoO42− adsorption is a complex process, occurring in two different steps, one controlled by diffusion and the second one controlled by mass transfer. Further, studies were performed in order to determine the optimum pH value needed to obtain maximum adsorption capacity, but also to determine which are the adsorbed species. From pH and desorption studies, it was proven that molybdate adsorption is a physical process. In order to establish the adsorption mechanism, the thermodynamic parameters (ΔG0, ΔH0 and ΔS0) were determined.

In this study series of CdxZn1-xS solid solutions with different amounts of Cd and Zn were synthesized by the hydrothermal treatment of aqueous solutions containing CdCl2, Na2S · 9 H2O and ZnSO4 · 7 H2O. The aim was to examine the influence of Zn concentration and processing conditions (hydrothermal temperature and duration) on the structure of the obtained powders and their photocatalytic activity (in water splitting process). The obtained photocatalysts (with and without Pd co-catalyst) were analysed by X-ray diffraction (XRD), atomic absorption spectroscopy (AAS), ultraviolet-visible spectroscopy (UV-VIS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) method and gas chromatography (GC). The XRD results confirmed the crystallinity of the compounds and transition from hexagonal to cubic phase with increasing Zn content. Complete transformation from hexagonal to cubic phase did not take place, and both phases were present in almost all samples. BET analysis showed the importance of the pore distribution and pore size, especially in the case of photocatalysts with different duration treatment. GC measurements of the photocatalysts without and with Pd co-catalyst confirmed the production of hydrogen for all tested compounds. The best photocatalytic performance was achieved by the sample Zn50230/72-Pd prepared at 230 °C, for 72 hours, with 50% Zn and in the presence of Pd co-catalyst. The synthesis implied neither stabilizer nor organic compound.

This study aimed to evaluate the comparative biological effects of Polygonum aviculare L. herba (PAH) extract and quercetin-entrapped liposomes on doxorubicin (Doxo)-induced toxicity in HUVECs. HUVECs were treated with two formulations of liposomes loaded with PAH extract (L5 and L6) and two formulations of liposomes loaded with quercetin (L3 prepared with phosphatidylcholine and L4 prepared with phosphatidylserine). The results obtained with atomic force microscopy, zeta potential and entrapment liposome efficiency confirmed the interactions of the liposomes with PAH or free quercetin and a controlled release of flavonoids entrapped in all the liposomes. Doxo decreased the cell viability and induced oxidative stress, inflammation, DNA lesions and apoptosis in parallel with the activation of Nrf2 and NF-kB. Free quercetin, L3 and L4 inhibited the oxidative stress and inflammation and reduced apoptosis, particularly L3. Additionally, these compounds diminished the Nrf2 and NF-kB expressions and DNA lesions, principally L4. PAH extract, L5 and L6 exerted antioxidant and anti-inflammatory activities, reduced γH2AX formation and inhibited extrinsic apoptosis and transcription factors activation but to a lesser extent. The loading of quercetin in liposomes increased the cell viability and exerted better endothelial protection compared to free quercetin, especially L3. The liposomes with PAH extract had moderate efficiency, mainly due to the antioxidant and anti-inflammatory effects and the inhibition of extrinsic apoptosis.

Gold is one of the precious metals with multiple uses, whose deposits are much smaller than the global production needs. Therefore, extracting maximum gold quantities from industrial diluted solutions is a must. Am-L-GA is a new material, obtained by an Amberlite XAD7-type commercial resin, functionalized through saturation with L-glutamic acid, whose adsorption capacity has been proved to be higher than those of other materials utilized for gold adsorption. In this context, this article presents the results of a factorial design experiment for optimizing the gold recovery from residual solutions resulting from the electronics industry using Am-L-GA. Firstly, the material was characterized using atomic force microscopy (AFM), to emphasize the material’s characteristics, essential for the adsorption quality. Then, the study showed that among the parameters taken into account in the analysis (pH, temperature, initial gold concentration, and contact time), the initial gold concentration in the solution plays a determinant role in the removal process and the contact time has a slightly positive effect, whereas the pH and temperature do not influence the adsorption capacity. The maximum adsorption capacity of 29.27 mg/L was obtained by optimizing the adsorption process, with the control factors having the following values: contact time ~106 min, initial Au(III) concentration of ~164 mg/L, pH = 4, and temperature of 25 °C. It is highlighted that the factorial design method is an excellent instrument to determine the effects of different factors influencing the adsorption process. The method can be applied for any adsorption process if it is necessary to reduce the number of experiments, to diminish the resources or time consumption, or for expanding the investigation domain above the experimental limits.

Silicon-based mesoporous materials have become increasingly used in various fields as industry, medicine, environment, etc. We developed five samples in mild conditions, at room temperature, of mesoporous silica by substituting tetra-ethyl-orthosilicate (TEOS) with different amount of sodium silicate (Na2Si3O7) precursor by maintaining the total ratio for SiO2 at 1.8g. Acetic acid (CH3COOH)/hydrochloric acid (HCl) aqueous solution was used as catalyst keeping the pH at 5. The samples were examined by FT-IR, Raman Spectroscopy, Scanning Laser Confocal Microscopy and Nitrogen Adsorption-Desorption Isotherms. The results indicate enhancements when Na2Si3O7 was added. Sample with TEOS and lowest amount of Na2Si3O7 displayed the best surface area value (750 m²/g) and total pore volume (0.63 cm³/g). Highest amount of Na2Si3O7 in the sample (P5) has considerably influenced the roughness of the material. [ABSTRACT FROM AUTHOR]