Browsing by Author "Gur, T."

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Characterisation, Antibacterial and Antioxidant Effects of Mountain Tea (Sideritis L.) Mediated Silver Nanoparticles in Preventing Dna Damage
(Springer, 2025) Gur, T.; Bekmezci, M.; Meydan, I.; Seckin, H.; Sen, F.
Nanoparticle-based products formed by combining atomic and molecular level materials find their place in many fields such as industry, cosmetics, medicine and pharmacy. In our study, we synthesised Ag NPs from mountain tea (Sideritis L.) using green chemistry method and demonstrated their material properties by characterisations such as SEM, EDX, FT-IR, XRD and UV-Vis spectroscopy. It was observed that the obtained silver nanoparticles formed inhibition zone diameters of 18 mm, 10 mm and 10 mm against Bacillussubtilis ATCC 6633, Pseudomonasaeruginosa ATCC 27853 and Staphylococcusaureus ATTC 29213 bacteria, respectively. Candidaalbicans ATTC 90028 pathogen, which we used as a fungus, formed a zone diameter of 10 mm. In addition the effect of Ag NPs against DNA damage was determined by gel electrophoresis method. In the images, it is seen that the damaged DNA in the 2 end well is preserved due to the increase in concentration. The effects of Ag NPs used in the 5th and 6 th wells are much better seen compared to the others. Ag NPs showed strong resistance to possible DNA damage. DPPH method was used to investigate the antioxidant effects of AgNPs produced by green synthesis, which is a biological procedure, and as a result, the radical quenching activity of mountain tea was found to be quite good with a value of 80% compared to the positive control BHA. We hope that Ag NPs synthesised from mountain tea, whose structure and properties have been extensively elucidated by various methods, may have a wide range of uses that can serve humanity.
Immobilization of Catalase Via Adsorption Into Natural and Modified Active Carbon Obtained From Walnut in Various Methods
(Academic Journals, 2009) Alkan, S.; Gur, A.; Ertan, M.; Savran, A.; Gur, T.; Genel, Y.
In the present work, the immobilization of catalase into natural active carbon and active carbon modified by hydrochloric acid was carried out. In the experimental section, the effects of pH, ionic strength and reaction temperature were chosen as parameters, with experiments performed in batch system. For the optimization of immobilization procedure, values of kinetic parameters were evaluated. It was observed that storage and operational stabilities of the enzyme increased with immobilization. The results obtained from experiments showed that active carbon is a valuable support for the adsorption of enzymes.
Immobilization of Catalase Via Adsorption Onto Natural and Modified Montmorillanit Analsim-Clay
(Polish Chemical Soc, 2009) Alkan, S.; Gur, T.; Gur, A.; Uruc, H.; Demir, H.
Immobilization of the enzyme catalase on natural and modified montmorillanit analsim-clays was investigated using a batch system. Such an immobilization does not result in enzyme inactivation and constitutes a valuable method for immobilizing catalase at high ionic strength. In the immobilization process, the effect of pH, ionic strength and reaction temperature were chosen as parameters. Furthermore the optimization of immobilization conditions were studied using data obtained from experimental results. For the free catalase and three different immobilized catalase enzymes, the optimum pH values 8, 7, 7 and 8; reaction temperature 30 degrees C; ionic strength 0.25 M were found. It was determined that enzyme activity for enzyme supported by natural clay was 73.3%, when it was retained during the storage at 4 degrees C for a period of 60 days. It was observed that storage and operational stabilities of the enzyme increased with immobilization. The results obtained show that montmorillanit analsim-clay is valuable and favourable support the simple adsorption of enzymes.
Immobilization of Polyphenol Oxidase Purified From Igdir Apricot on Bardakci-Clay
(2008) Demir, H.; Gur, A.; Yilidz, A.; Gur, T.
It is known that immobilized enzymes more useful and advantageous than free enzymes. In this work, polyphenol oxidase purifed by affinity chromatography from lgdir apricot was immobilized onto natural bardakci-clay by physical adsorption method. The properties of the immobilized enzyme were compared to the tree enzyme. The PPO activity of immobilized clay was determined, and then the effects of reaction optimum temperature, thermostability, optimum pH, ionic effect and kinetic parameters were investigated. Catechol was used as substrate, the activities of immobilized and free polyphenol oxidase were determined in the reaction mixture containing substrate catechol. The results obtained from experiments indicated that physical adsorption is favourable for attachment of enzyme onto bardakci-clay.
Ternary/Quaternary Nanomaterials for Direct Alcohol Fuel Cells
(Elsevier, 2021) Altuner, E.E.; Gur, T.; Şen, F.
In this chapter, ternary and quaternary nanomaterials that increase electrocatalytic activity in direct alcohol fuel cells (DAFCs) are mentioned. Because nanosized materials achieve their target quickly due to the desired nanostructure, they give quite good results. These types of materials also increase activation and efficiency of the alcohol oxidation reaction in DAFCs. Undesired reactions occurring at the anode and cathode in DAFCs, the instability of platinum, and its corrosion have led to the need for multiple nanoelectrocatalysts such as ternary and quaternary supporting platinum. For this reason, binary, ternary, and quaternary systems were created to be able to increase the efficiency of the DAFCs. © 2021 Elsevier Inc. All rights reserved.