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    Anion effect on magnetic and structural properties of green synthesized NiO nanoparticles via Ni.salt precursors in Salvia officinalis extract
    (Chinese Chemical Soc, 2024) Zenkin, Kubra; Dalmaz, Aslihan; Ozdincer, Mesut; Durmus, Sefa
    Using a green synthesis method, Salvia officinalis extract was used as a reducing and capping agent to synthesize nickel oxide nanoparticles (NiO NPs). In addition, NiO NPs were synthesized using various precursors, and their morphologies were analyzed using scanning electron microscopy. The structures of NiO NPs were characterized using Fourier-transform infrared spectroscopy, and powder X-ray diffraction (PXRD). Their magnetic properties were measured using a vibrating sample magnetometer. PXRD studies showed that all synthesized NiO NPs exhibited a face-centered cubic phase with high crystallinity, and NiO formations with a high-purity phase were confirmed. As a result of magnetization studies, NiO NPs synthesized from three nickel salt precursors (acetate, chloride, and sulfate) exhibit superparamagnetic, soft ferromagnetic, and paramagnetic behaviors, respectively.
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    Biological evaluation of benzothiazoles obtained by microwave-green synthesis
    (Acad Brasileira De Ciencias, 2024) Ozdincer, Mesut; Dalmaz, Aslihan; Durmus, Sefa; Dülger, Görkem; Kiliccioglu, Ilker
    Benzothiazole compounds are known as an important bicyclic ring system with multiple applications. These compounds have a wide range of biological activities, including anticancer, antimicrobial, anti-inflammatory and antiviral activities. In this study, benzothiazole compounds were synthesized and their various biological activities were examined. The synthesized benzothiazoles were evaluated for their antimicrobial properties against various bacterial and fungal strains. The compound 6e is most active ligand in the series against bacteria and fungi as compared to standard antibiotics. Especially, this compound significant effect against Staphylococcus aureus (32.00 +/- 1.73 mm). These compounds exhibited potent anticancer activity against gastrointestinal cancer cells, demonstrating their potential as therapeutic agents. The lowest antiproliferative response after administration of the compounds was observed in HCT116 cells, while the most effective antiproliferative response was observed in AGS cells (> 10 mu g/mL). In all cell lines, 40 and 100 mu g/mL application values of the selected compounds showed significant increases in the expression of caspase-3, 8 and 9. We also utilized a computational docking approach to investigate the interaction of these benzothiazoles with VEGFR-2 kinase. Our docking studies showed that compounds 6a and 6d may be promising therapeutic agents against gastrointestinal system cancers due to their ability to bind to VEGFR-2 kinase.
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    Green synthesis of ZnO nanoparticles using Laurus nobilis L. extract and investigation of corrosion inhibition properties of DES-based nanofluids
    (Springer, 2024) Dalmaz, Aslihan; Kasimfirtina, Eren; Ozak, Sezen Sivrikaya
    In this study, new nanofluids based on four different deep eutectic solvents consisting of acetic acid and ethylene glycol as hydrogen bond acceptors, choline chloride, and water as hydrogen bond donor were prepared and these deep eutectic solvents, ZnO used to influence the corrosion of nanoparticles. The study's originality is that for the first time in this study, ZnO nanoparticles obtained with the help of the green material deep eutectic solvent and the extract of Laurus nobilis L. leaves were used effectively in the corrosion study. As a result of the corrosion studies, the best corrosion prevention efficiency was determined in the nanofluid prepared by adding 0.015% by weight ZnO nanoparticles. According to the XRD analysis results, the synthesized ZnO nanoparticles are formed in a hexagonal structure. When the SEM images of ZnO nanoparticles were examined, it was seen that the obtained structure was homogeneous, and the dimensions of the nanoparticles varied between 12 and 33 nm. The thermal stability of ZnO nanoparticles was proven from the TGA curve, where only a 2% weight loss was observed. ZnO nanoparticles did not undergo any degradation up to 1000(degrees)C.
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    Hydrophilic deep eutectic solvent based microextraction procedure for the determination of four paraben preservatives in vitamin D for babies: A green approach
    (Elsevier, 2023) Akmes, Ali; Dalmaz, Aslihan; Ozak, Sezen Sivrikaya
    In this study, an easily available, sensitive, and fast hydrophilic deep eutectic solvent-liquid phase microextraction method developed using deep eutectic solvent (DES) as a green solvent for the determination and microextraction of paraben (methyl, ethyl, propyl, and butyl) preservatives in vitamin D for babies. The highest yield for extraction recovery was obtained using DES consisting of a 1:4 M ratio of choline chloride and acetic acid. Moreover, various optimization parameters such as DES volume, DES type, sample volume, and centrifugation time were investigated in order to develop a real sample specific microextraction method. Relative standard deviation values were 0.92%-2.87%, the detection limit was 0.194-0.254 & mu;g/mL, and extraction recovery values were between 87.40% and 102.98%. The method developed in this study was successfully applied to 5 different babies in vitamin D for babies obtained from pharmacies for the determination of methyl, ethyl, propyl, and butylparaben. As far as we know, it is the first study conducted both in terms of the determination of paraben preservatives in vitamin D for babies and in terms of the fact that DES used in this study is used for the first time in vitamin D for babies.
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    Methylene blue dye efficient removal using activated carbon developed from waste cigarette butts: Adsorption, thermodynamic and kinetics
    (Elsevier Sci Ltd, 2024) Dalmaz, Aslihan; Sivrikaya Ozak, Sezen
    This study aimed to obtain activated carbon using waste cigarette butts, which is one of the most harmful and toxic environmental materials. In addition, cigarette butts were converted into activated carbon in the thermal carbonization stage using ZnCl2 (1:2 ratios by mass) as a chemical activator. Brunauer-Emmett-Teller test, Fourier transform infrared spectrometry, Scanning electron microscope, and Elemental analysis were used to determine the activated carbon's surface morphology, elemental composition, functional group, and surface properties. As a result of the Brunauer-Emmett-Teller test, it was observed that the activated carbon obtained had a high surface area of 667.9 m2/g. In the study, it was determined that the Langmuir model can best describe the adsorption isotherm model. In addition, the maximum adsorption capacity of activated carbon for methylene blue dye was 285.7 mg g -1 at 25 degrees C. The results obtained in the study support that the pore structure of cigarette butts will be one of the strong alternatives in the production of activated carbon for the removal of methylene blue dye.