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Öğe Assesment the role of oxidative stress and efficacy of caffeic acid phenethyl ester (CAPE) on neurotoxicity induced by isoniazid and ethambutol in a rat model(Verduci Publisher, 2014) Uzar, E.; Varol, S.; Acar, A.; Firat, U.; Basarslan, S. K.; Evliyaoglu, O.; Yucel, Y.OBJECTIVE: The aim of this study were to investigate a role of oxidative stress and the therapeutic efficacy of caffeic acid phenethyl ester (CAPE) in the pathogenesis of neurotoxicity induced by isoniazid and etambutol in a rat model. MATERIALS AND METHODS: Male Sprague-Dawley rats were randomly divided into eight experimental groups: control, INH, ETM, INH+ETM, INH+CAPE, ETM+CAPE, INH+ETM+CAPE, and CAPE treatment group, with ten animals in each group. INH and ETM doses were given orally within tap water for 30 days. CAPE was administered into relevant groups intraperitoneally for 30 days. Brain tissue and sciatic nerve were removed for biochemical and histopathological investigation. RESULTS: In the INH, ETM, and INH+ETM groups, malondialdehyde (MDA) and total oxidant status (TOS) levels were significantly higher than those of the control group (p < 0.05). Also, in these groups, brain total antioxidant capacity (TAC) levels, and superoxide dismutase (SOD) and PON-1 activities were decreased compared with the control group (p < 0.05). By a CAPE supplement within INH and ETM groups, there was a significant decrease in MDA and TOS (p < 0.05). In addition to a significant increase in TAC levels, and SOD and PON-1 activities both in brain and sciatic nerve tissues (p < 0.05). CONCLUSIONS: CAPE may protect against INH- and ETM-induced neurotoxicity in rat brain and sciatic nerve.Öğe The Enzymatic Production of Biodiesel from Pomace Oil Using Immobilized Thermomyces lanuginosus(Taylor & Francis Inc, 2013) Yucel, Y.In the present work, microbial lipase from Thermomyces lanuginosus was immobilized by covalent binding onto styrene-divinylbenzene polyglutaraldehyde copolymer. Immobilized support material was used to produce biodiesel with pomace oil and methanol. The properties of the support and immobilized derivative were evaluated by scanning electron microscopy. Biodiesel production was carried out with a semi-continuous operation system. Methanol was added into the reactor by three successive additions of 1:6 molar equivalent of methanol to avoid enzyme inhibition. The maximum methyl esters yield was obtained as 98%.Öğe Methods for Lipase Immobilization and Their Use for Biodiesel Production from Vegetable Oil(Taylor & Francis Inc, 2014) Yucel, Y.; Demir, C.; Dizge, N.; Keskinler, B.In the present work, two different lipases (triacylglycerol hydrolase, EC 3.1.1.3), Lipozyme TL-100L and Novozyme 388, were immobilized onto three different low-cost supports using both adsorption and covalent method: celite 545, silica gel, and styrene-divinylbenzene copolymer. The maximum immobilization yield was obtained as 79.0% for Lipozyme TL-100L and the highest specific activity was 6.5 U/mg protein for Novozym 388. The properties of the support and immobilized derivatives were characterized by Fourier transform infrared spectroscopy. Maximum methyl esters yield was obtained as 98.3%. The lipases, which are immobilized by covalently, proved to be stable after even 10 repeated reuses.Öğe The Optimization of Immobilized Lipase-catalyzed Transesterification of Canola Oil by Response Surface Methodology and Mixture Design(Taylor & Francis Inc, 2012) Yucel, Y.; Demir, C.The abilities of three immobilized lipases from Candida Antarctica (Novozym 435), Thermomyces lanuginosus (Lipozyme TL-IM), and Rhizomucor miehei (Lipozyme RM-IM) to catalyze the transesterification of canola oil with methanol were investigated. Response surface methodology and central composite design were employed to optimization of the reaction parameters. Simplex lattice mixture design was employed to evaluate the effect of the composition of lipase mixtures on the yield of transesterification reaction. The highest conversion of canola oil to fatty acid methyl ester was obtained as 97.2%. Mixture of lipases could be used to obtain higher conversion of canola oil to biodiesel.