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2011 - 202020
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Yazar: Levent, Abdulkadir × Tam Metin: false ×

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    The changes in the serum, liver, kidney protein and genomic DNA profiles in rats treated with 7,12-Dimethylbenz(A) anthracene and Plantago major L.
    (RJPBCS, 2014-01) Berber, İsmet; Ekin, Suat; Levent, Abdulkadir; Oto, Gökhan;
    In the study, the changes in the serum, liver, kidney protein and genomic DNA profiles in Wistar albino rats administrated to 7,12-dimethylbenz(a)anthracene (DMBA) and Plantagomajor L. were investigated. SDS-PAGE profiling of the serum proteins showed that the levels of two proteins molecular weighing 140.8 kDa and 46.8 kDa were significantly lower on the 0th day of treatment than on the 60th day of application in the groups. Furthermore, two proteins (34.5 and 22.3 kDa) were solely present in DMBA-treated liver cell lysates. On the contrary, the kidney protein profiles did not show significant banding variations in groups. Genomic DNA analysis also confirmed that DNA extracted from liver and kidney cells did not fragment in any of the groups after the 60th study day. The proteins 34.5 and 22.3 kDa in liver cell lysates at the 60th day in DMBA-treated group could be extra-prognostic indicators for severe DMBA toxicity.
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    New voltammetric strategy for determination and electrochemical behaviors of metformin by pencil graphite electrode in the NaOH
    (Indian Chemical Society, 2020) Altunkaynak, Yalçın; Yavuz, Ömer; Levent, Abdulkadir
    Metformin(MET), an oral antidiabetic drug commonly used in the treatment of diabetes, is a drug that increases insulin sensitivity in the biguanide group [1]. MET shows its pharmacological effect by lowering the glucose level in the blood. In the literature research, there are studies using electrochemical techniques for the analysis of MET in biological fluid and drug forms[1-6]. In this study, the electrochemical properties of MET, one of the drugs used in the treatment of diabetes, were performed using a pencil graphite electrode in NaOH (0.1 M) solution. This compound was recorded with an irreversible and diffusion controlled adsorption oxidation peak at approximately +1.28 V by cyclic voltammetry. With square wave stripping voltammetry, it was observed that the peak current signals of MET in the concentration range of 2.76-24.8 µM in 0.1M NaOH solution increased linearly. At a concentration of 2.76 µM (n = 9), the limit of detection and relative standard deviation were calculated as 9.03 nM (1.495 ngmL-1 ) and 3.25 %, respectively. This method has been successfully applied for MET analysis in pharmaceutical preparations and urine samples without any separation.
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    Plantago major protective effects on antioxidant status after administration of 7,12-dimethylbenz(a)anthracene in rats
    (Asian Pacific Organization for Cancer Prevention, 2011) Oto, Gökhan; Ekin, Suat; Özdemir, Hülya; Demir, Halit; Yaşar, Semih; Levent, Abdulkadir; Berber, İsmet; Kaki, Barış
    Aim: The present study was designed to evaluate effects of Plantago major extract on oxidative status in Wistar albino rats administrated 7,12-dimethylbenz(a)anthracene (DMBA). Methods: Rats were divided into three equal groups of 6 animals each: Group 1 controls, group 2 treated with DMBA (100 mg/kg, single dose) and group 3 receiving the DMBA and the aqueous extract at 100 mg/kg/d for 60 days. Results: Significant decrease in catalase (P<0.05), carbonic anhydrase (p≤0.01), reduced glutathione (GSH) (P<0.01) and total protein (P<0.01) values was observed in the DMBA group compared with the healthy controls and DMBA + Plantago major groups. Conclusion: The results suggest preventive effects of Plantago major on DMBA induced oxidative damage in Wistar albino rats that might be due to decreased free radical generation.
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    Electroanalytical investigation of antineoplastic drug vinorelbine at pencil graphite electrode in surfactant media
    (Turkish Chemical Society, 2019) Önal, Günay; Levent, Abdulkadir; Şentürk, Zühre
    Vinorelbine (sold under the brand name Navelbine), one of the semisynthetic derivatives of Vinca alkaloids, has been widely used either alone or in combination with other drugs in the tre- atment of leukemia, lymphoma, advanced testicular cancer and Kaposi's sarcoma. From the electrochemical point of view, only one study that was quite old has been reported on its voltammetric characteris- tics so far (Brett et al.). Keeping the above knowledge in mind, in the present study, a novel application of single-use pencil graphite (PG) electrode is introduced for the determination of Vinorelbine. The electrochemical oxidation of this compound was first investigated by cyclic voltammetry in aqueous solutions. Special attention was given to the use of adsorptive stripping vol- tammetry at a surface of PG electrode and glassy carbon (GC) one (for comparison purpose) in aqueous solutions over the pH range of 2.0-12.0 both without and with the addition of different charged surfactants. The sensitivity of the stripping voltammet- ric measurements was significantly improved when the anionic (sodium dodecylsulfate, SDS) and cationic (tetra-n-butylammo- nium bromide, TBAB) surfactants were present in the Vinorelbi- ne-containing electrolyte solution at pH 2.0-4.0 and pH 9.0-10.0, respectively, by using PG electrode. Using square-wave stripping mode, Vinorelbine yielded a well-defined voltammetric response in Britton-Robinson buffer pH 10.0 containing 3×10−3 M TBAB at +0.75 V (vs. Ag/AgCl) (after 120 s accumulation at +0.0 V). The process could be used to determine this compound in the concentration range of 2.3×10−8 – 5.8×10−6 M, with a detection limit of 7.5×10−9 M (base-5.8 ng mL1−). The proposed method was successfully applied to pharmaceutical formulations and the spiked human urine samples.
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    Simultaneous electrochemical evaluation of ascorbic acid, epinephrine and uric acid at disposable pencil graphite electrode: Highly sensitive determination in pharmaceuticals and biological liquids by differential pulse voltammetry
    (Elsevier, 2018) Levent, Abdulkadir; Önal, Günay
    Aim and Objective: As is known, AA, EP and UA can also coexist in biological fluids. Therefore, the determination of the levels of these compounds in biological fluids is extremely important both for the diagnosis and treatment of the related diseases. In the presence of many interfering substances in biological fluids such as blood and urine samples, it is very important that these compounds can be selectively analyzed. Materials and Methods: All electrochemical experiments were performed using an Autolab PGSTAT 128N potentiostat. Before beginning the electrochemical measurements, the PGE was activated. The electrochemical pretreatment of PG was exercised by anodically +1.40 V for 60 s. Then, measurements were performed with CV (-0.4 V to 1.2 V) and DPV (-0.2 V to 0.7 V) for single and simultaneous voltammetric behaviour of AA, EP, and UA in the electrochemical method. Results: The anodic peak potentials of AA and UA were observed at about +0.32 V and +0.62 V, respectively. On the other hand, for EP, while anodic peak potential was observed at about +0.53 V, in the reverse scan, cathodic peak potentials were observed at about +0.41 V and +0.007 V. The39 reduction peak observed at +0.3 V with the oxidation peak observed at +0.53 V are the reversible peaks. In the method developed for the electrochemical simultaneous determination of AA, EP and UA using PGE with DPV technique in BR buffer solution (pH 4.0), the anodic peak potentials are sufficiently separated from each other. Conclusion: A voltammetric method was developed for the simultaneous determination of AA, EP and UA with PGE for the first time. Here, the most important thing is that the simultaneous determination of AA, EP and UA was successfully achieved with that targeted voltammetric method which was sensitive, low-cost, practical and well-repeated; and that these were proven to be selectively applicable in pharmaceutical products and biological liquids.
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    Electroanalytical determination of progesterone hormone using borondoped diamond electrode
    (ICNTC, 2020) Levent, Abdulkadir; Uçar, Muhlis
    Progesterone is synthesized from pregnenolone, a derivative of cholesterol like other steroids. It is a steroid hormone that has a vital importance in human and animal health. In case of progesterone imbalance, it causes problems such as fertility and infertility. In this study, electrochemical properties of Progesterone hormone Boron doped diamond (BDD) on electrode surface were investigated in strongly acidic environment (HClO4 and H2SO4). A fast, sensitive, selective and simple electroanalytical method was developed for cathodically pre-treated BDD electrodes. A good linear analytical curve in the concentration range of 10 μM to 100 μM at a voltage value of +1.51 V (vs. Ag / AgCl) (after 120 s deposition at +0.1 V voltage) in 0.5 M HClO4 using the square wave stripping technique for the quantification of progesterone hormone obtained. The observability limit is 0.012 µM(3.77 µg L-1); The relative standard deviation value (RSD) for the concentration of 3.1 µM (n = 11) was calculated to be 4.87%. In addition, the developed voltammetric method has been successfully applied to drug and blood serum.
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    New voltammetric strategy for determination and electrochemical behaviors of metformin by pencil graphite electrode
    (ICNTC, 2020) Altunkaynak, Yalçın; Yavuz, Ömer; Levent, Abdulkadir
    Metformin(MET), an oral antidiabetic drug commonly used in the treatment of diabetes, is a drug that increases insulin sensitivity in the biguanide group [1]. MET shows its pharmacological effect by lowering the glucose level in the blood. In the literature research, there are studies using electrochemical techniques for the analysis of MET in biological fluid and drug forms[1-6]. In this study, the electrochemical properties of MET, one of the drugs used in the treatment of diabetes, were performed using a pencil graphite electrode in NaOH (0.1 M) solution. This compound was recorded with an irreversible and diffusion controlled adsorption oxidation peak at approximately +1.28 V by cyclic voltammetry. With square wave stripping voltammetry, it was observed that the peak current signals of MET in the concentration range of 2.76-24.8 µM in 0.1M NaOH solution increased linearly. At a concentration of 2.76 µM (n = 9), the limit of detection and relative standard deviation were calculated as 9.03 nM (1.495 ngmL-1 ) and 3.25 %, respectively. This method has been successfully applied for MET analysis in pharmaceutical preparations and urine samples without any separation.
  • Küçük Resim Yok
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    Batman Üniversiteli kadın akademisyenin bilimsel profili
    (Batman Üniversitesi, 2017) Kaçmaz Levent, Esra; Levent, Abdulkadir