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Öğe The Activity and Reproductive Pattern of Testudo graeca in Cappadocia Region, Anatolia(Wiley, 2017) Arslan Akveran, Gönül[Abstract Not Available]Öğe Effect of immobilization on the activity of catalase carried by poly(HEMA-GMA) cryogels(Elsevier B.V., 2019) Erol, Kadir; Koncuk Cebeci, Büşra; Köse, Kazım; Köse, Dursun AliHydrogen peroxide is converted by catalase to molecular oxygen and water to remove oxidative stress. In this study, catalase immobilization was performed using poly(2-hydroxyethyl methacrylate-glycidyl methacrylate) (poly(HEMA-GMA)) cryogels with different amounts of GMA. Catalase adsorption capacity of 298.7 ± 9.9 mg/g was achieved at the end of 9 h using the poly(HEMA-GMA)-250 cryogel. Kinetic parameters and the inhibitory effects of pesticides such as 4,4?-DDE and 4,4?-DDT on the activity of free and immobilized catalase enzyme were investigated. While the V max value of the immobilized enzyme was reduced 4-fold compared to the free enzyme, in the case of the comparison of the K M values, the affinity of the immobilized enzyme was increased by 1.94 times against the substrate. The inhibitory effect of 4,4?-DDT pesticide was found to be higher for the immobilized and free enzyme. NaCl (1 M, pH: 7.0) solution was used for desorption of the adsorbed catalase enzyme. A desorption ratio of 96.45% was achieved. The technique used in this study is promising regarding for the immobilization of catalase enzyme to increase the operational activity. Therefore, poly(HEMA-GMA) cryogels have the potential to be used for immobilization of catalase enzyme in the fields of biology and biochemistry. © 2018 Elsevier B.V.Öğe Lead removal from industrial waste(Hitit University, 2017) Bilgin, Elif; Yüce, Murat; Köse, Kazım; Erol, Kadir; Köse, Dursun AliIn this study, the heavy metal removal performance of poly(2-hydroxyethyl methacrylate-N-methacryloyl-(L)-histidine methyl ester), poly(HEMA-MAH) cryogel, a known polymer, in HNO3 was investigated. To determine the heavy metal removal performance of cryogel, wastewater was used as obtained from an inorganic material manufacturer. The characterization studies using scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, elemental analysis, waterswelling tests and surface area analysis were conducted. The effect of HNO3 on the adsorption process, especially for metals, was found very effective even in trace amounts.Öğe Nicotinamide-modified poly(HEMA-GMA)-Nic cryogels for removal of pesticides(Turkish Chemical Society, 2018) Köse, Kazım; Arslan Akveran, Gönül; Erol, Kadir; Köse, Dursun AliChlordane is only one of the persistent pesticides used in some countries despite the ban. Removal of chlordane, a severe threat to all living things, was performed using nicotinamide-modified poly (2-hydroxyethyl methacrylate-glycidyl methacrylate), poly(HEMA-GMA)-Nic, polymeric cryogels in this study. Poly(HEMA-GMA) polymeric cryogels were synthesized based on previously reported literature procedures and were subsequently modified by nicotinamide moieties. Removal of chlordane in alcoholic medium has been accomplished exploiting the alcoho-phobic interaction, which was the first indication in our previous study. Structural analysis of poly(HEMA-GMA)-Nic was performed using Fourier transform infrared spectroscopy (FT-IR) and elemental analysis methods. Scanning electron microscopy (SEM) was used to understand the surface morphology of cryogels. Surface area and cavity volume calculations were determined by applying N 2 adsorption method and swelling test. The interaction time and maximum adsorption capacity were identified as 5 minutes and 64.61 mg chlordane/g cryogel for 300 mg/L chlordane concentration and 108.818 mg chlordane/g cryogel for 800 mg/L chlordane concentration during the adsorption experiments. Cyclohexane, toluene, chloroform, dichloromethane, acetone, and acetonitrile were used as solvents to observe the solvent effect on adsorption of chlordane onto the polymeric material. As expected, the removal of chlordane was performed with the highest adsorption performance in cyclohexane with the lowest dielectric constant. © 2018, Turkish Chemical Society. All rights reserved.Öğe Solvent effect on endosulfan adsorption onto polymeric arginine-methacrylate cryogels(Springer Verlag, 2018) Arslan Akveran, Gönül; Köse, Kazım; Köse, Dursun AliEndosulfan is a persistent insecticide that is still used in some countries even though it is life-threatening and banned in the agricultural struggle. The solubility of pesticides in water is negligible. It is known that pesticides with better solubility in organic solvents have different solubility when the dielectric constants of these solvents are taken into account. The polymeric structure of arginine was modified with methacrylate to be a functional monomer, and it was immobilized on a solid support, poly(HEMA), and finally, poly(2-hydroxyethyl methacrylate-arginine methacrylate) was obtained and used as an effective adsorbent. The effect of organic solvents on endosulfan adsorption was investigated for the first time in the literature. Endosulfan was removed from alcohol media by using this polymeric structure synthesized by exploiting alcoho-phobic interaction in this work. Nuclear magnetic resonance (NMR), elemental analysis, and Fourier transform infrared spectroscopy (FTIR) methods were used for the structural characterization and therefore to prove successful synthesis of cryogels. Morphological characteristics were also investigated by scanning electron microscopy (SEM), an N2 adsorption method, and swelling test. Adsorption experiments were carried out against varying interaction time and concentration parameters in the batch system. Since the alcohol used as a solvent has a pH value close to the ionic strength of drinking water, no change was made in the pH of the solution. Endosulfan molecules dissolved in solvents such as toluene, dichloromethane, acetone, and chloroform were removed using poly(HEMA-ArMA) cryogels to determine the solvent effect on the adsorption of endosulfan. As expected, the removal of endosulfan from the solvent toluene provided the best result. Although the adsorption in toluene is almost 9.5 times higher than that in ethanol, the use of toluene in the adsorption process due to its chemical structure is not feasible. Thus, experiments were carried out in ethanol. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature.Öğe Isolation of aspartic acid using Novel Poly(2-hydroxyethyl methacrylate-N-methacryloyl-(l)-lysine) Cryogels(Friedr. Vieweg und Sohn Verlags GmbH, 2018) Sarıca, Büşra; Köse, Kazım; Uzunoğlu, Aytekin; Erol, Kadir; Köse, Dursun AliIn this study, we report on the synthesis of novel poly(2-hydroxyethyl methacrylate-N-methacryloyl-(l)-lysine) [poly(HEMA-MAL)] cryogels for the isolation of aspartic acid. Cryogels were characterized using nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), N2-adsorption, swelling test, and elemental analysis techniques. The FTIR and elemental analysis results showed successful synthesis of poly(HEMA-MAL)-based polymeric structures. SEM images and N2 adsorption results indicated the three-dimensional morphology and large surface area of the cryogels. After the synthesis and characterization steps, adsorption performance of these novel cryogels towards l-aspartic acid was evaluated and adsorption capacity was found to be 265.7 ± 3 mg aspartic acid g?1 adsorbent. To show the applicability of our adsorbent design for the isolation of aspartic acid from real samples, adsorption and desorption experiments using lysozyme enzyme were also performed. Our results showed that the proposed cryogel design can be successfully employed for the isolation of amino acids from complex environments. It can be stated that poly(HEMA-MAL)-based cryogels are promising candidates for the isolation of aspartic acid and lysozyme owing to their enhanced performance and specificity, low cost, and high reusability. © 2017, Springer-Verlag GmbH Germany.Öğe In vitro effects of pesticide exposure on the activity of the paraoxonase-1 enzyme from sheep liver microsomes(The Scientific and Technological Research Council of Turkey (TÜBİTAK), 2014) Koncuk Cebeci, Büşra; Alım, Zuhal; Beydemir, ŞükrüThe organophosphate target enzyme paraoxonase-1 (PON1) has been extensively studied in toxicology. Pesticides are organophosphate compounds that are commonly used in agriculture. They are also used as nerve gases, such as sarin and soman. Therefore, the effects of these compounds on enzymatic activity are well known. In the present study, we investigated the in vitro effects of fenoxaprop-p-ethyl, lambda cyhalothrin, imidacloprid, and dichlorvos pesticides on sheep liver microsomal PON1. The enzyme was purified approximately 141-fold with a specific activity of 1822.22 EU/mg proteins. The pesticides inhibited sheep liver PON1 in vitro, and the IC_ {50} values for these compounds were 0.0103, 0.069, 0.157, and 0.2\mu M, respectively.
