Fakülteler / Faculties

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    Sensitive And Cost-Effective Boron Doped Diamond And Fe2O3/Chitosan Nanocomposite Modified Glassy Carbon Electrodes For The Trace Level Quantification Of Anti-Diabetic Dapagliflozin Drug
    (2022) Ozkan, Ece; Cetinkaya, Ahmet; Ozcelikay, Goksu; Nemutlu, Emirhan; Kir, Sedef; Ozkan, Sibel A.; https://orcid.org/0000-0001-5014-0907; AAF-6076-2019
    Dapagliflozin (DPG), used in the treatment of type 2 diabetes, is a drug widely used to treat type 1 diabetes with certain restrictions. Hypoglycemia, urinary tract, genital infections, and decreased body water are among the common side effects of DPG. The detailed electrochemical oxidation process of DPG at both electrodes was investigated using cyclic voltammetry. The bare boron-doped diamond electrode (BDDE) showed a diffusion-controlled process, while the glassy carbon electrode (GCE) was an adsorption-controlled process. Using iron (III) oxide/Chitosan nanocomposite showed (Fe2O3/Chitosan NCs) as the modification agent for the GCE, a highly sensitive and selective nanosensor was created for the DPG assay. Fe2O3/Chitosan NCs modified GC, and bare BDD electrodes were successfully applied for the electrochemical determination of DPG. The simple, eco-friendly, sensitive, and time-saving electroanalytical methods have been developed for the determination of DPG in urine, serum, and tablet samples using differential pulse (DPV) and adsorptive stripping differential pulse voltammetric (AdSDPV) methods with a BDDE and the proposed nanosensor (Fe2O3/Chitosan NCs modified GCE) in 0.1 M H2SO4 containing 20% methanol, respectively. Under optimized conditions, the developed methods gave detection limits of 2.0 nM and 15 nM and linear range of 0.1-8.0 mu M and 0.6-80.0 mu M for Fe2O3/Chitosan NCs modified GCE and BDDE, respectively. Both electrodes showed excellent recoveries (between 97.25 and 102.68 %) and repeatability with RSD lower than 2.4% (n = 5). The developed methods were successfully applied for the analysis of DPG in serum, urine, and pharmaceutical dosage forms.
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    Is the revised 2018 FIGO staging system for cervical cancer more prognostic than the 2009 FIGO staging system for women previously staged as IB disease?
    (2019) Ayhan, Ali; Aslan, Koray; Bulut, Ayca Nazli; Akilli, Huseyin; Oz, Murat; Haberal, Ali; Meydanli, Mehmet Mutlu; 0000-0002-7495-5470; 31325847
    Objective: The purpose of this study was to compare the prognostic value of the revised FIGO staging system with that of the 2009 FIGO staging system for women previously staged as IB disease. Methods: Institutional cervical cancer databases of two high-volume gynecologic cancer centers in Ankara, Turkey, were retrospectively analyzed. Only women with 2009 FIGO stage IB1 or 1B2 disease who underwent primary surgery were included. Survival curves were generated using Kaplan-Meier plots, and the log-rank test was used for survival comparisons. The Cox proportional hazards regression model was used to obtain hazard ratios (HRs) and 95% confidence interval (CI). Results: Data from 425 women were analyzed. The 2009 FIGO stage IB2 (n = 131) disease was associated with a nearly three-fold increased risk of mortality when compared to the 2009 FIGO stage IB1 (n = 294) disease (HR: 2.72, 95% CI: 1.69-4.37; p < 0.001). Stage migration was observed in 372 (87.5%) patients, according to the revised FIGO staging system, leading to no significant difference in five-year overall survival rates between stage IB1 (n=53) and IB2 (n=127) disease (95.2% vs. 89.3%, respectively; p = 0.23),or between stage IB2 (n=127) and IB3 (n=95) disease (89.3% vs. 84.2%, respectively; p = 0.12). Similarly, there was no significant difference in five-year overall survival rates between stage IIIC1 (n=114) and IIIC2 (n=36) disease (79.0% vs. 67.2%, respectively; p = 0.34). Conclusion: When compared to the 2009 FIGO staging system, the revised staging system has more substages, which leads to fewer patients in each sub-stage, resulting in diminished statistical power. (C) 2019 Elsevier B.V. All rights reserved.