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Article Citation - WoS: 7Citation - Scopus: 6A platinum blue complex exerts its cytotoxic activity via DNA damage and induces apoptosis in cancer cells(Wiley, 2017) Adiguzel, Zelal; Ozalp-Yaman, Seniz; Celik, Gokalp; Salem, Safia; Bagci-Onder, Tugba; Senbabaoglu, Filiz; Acilan, CeydaHere, we describe the characteristics of a Pt-blue complex [Pt-4(2-atp)(8)(H2O)(OH)] (2-atp: 2-aminothiophenol) as a prodrug for its DNA-binding properties and its use in cancer therapy. The nature of the interaction between the Pt-blue complex and DNA was evaluated based on spectroscopic measurements, the electronic absorption spectra, thermal behavior, viscosity, fluorometric titration, and agarose gel electrophoresis. Our results suggested that the compound was able to partially intercalate DNA and appeared to induce both single- and double-stranded breaks (DBS) on DNA in vitro, but no DSBs in cells. The ability of the compound to induce DNA damage was dependent on reactive oxygen species (ROS) in vitro. There was also elevated formation of ROS and SOD expression in response to drug treatment in cell culture. The complex was found to be more cytotoxic to cancer cells in comparison with noncancer controls using WST-1 assay. The mean of cell death was determined to be apoptosis as assessed via biochemical, morphological, and molecular observations, including DNA condensation/fragmentation analysis, live cell imaging microscopy, TUNEL analyses, and increase in the levels of pro-apoptotic genes such as Bag3, Bak, Bik, Bmf, and Hrk. Hence, the Pt-blue complex under study grants premise for further studies.Article Fixed Point Results on Perturbed B-Metric Space(Univ Belgrade, Fac Electrical Engineering, 2025) Karapinar, ErdalIn this paper, we introduce the notion of perturbed b-metric spaces and consider some basic topological notions on this new abstract structure. In addition, we shall discuss the existing and uniqueness of a fixed point in the setting of perturbed b-metric spaces.Article Citation - WoS: 17Citation - Scopus: 27Fixed Point Theorems in New Generalized Metric Spaces(Springer Basel Ag, 2016) Karapinar, Erdal; Karapınar, Erdal; O'Regan, Donal; Roldan Lopez de Hierro, Antonio Francisco; Shahzad, Naseer; Karapınar, Erdal; Mathematics; MathematicsThe aim of our paper is to present new fixed point theorems under very general contractive conditions in generalized metric spaces which were recently introduced by Jleli and Samet in [Fixed Point Theory Appl. 2015 (2015), doi:10.1186/s13663-015-0312-7]. Although these spaces are not endowed with a triangle inequality, these spaces extend some well known abstract metric spaces (for example, b-metric spaces, Hitzler-Seda metric spaces, modular spaces with the Fatou property, etc.). We handle several types of contractive conditions. The main theorems we present involve a reflexive and transitive binary relation that is not necessarily a partial order. We give a counterexample to a recent fixed point result of Jleli and Samet. Our results extend and unify recent results in the context of partially ordered abstract metric spaces.Article Recognition and Misclassification Patterns of Basic Emotional Facial Expressions: An Eye-Tracking Study in Young Healthy Adults(MDPI, 2025) Alkan, NeşeAccurate recognition of basic facial emotions is well documented, yet the mechanisms of misclassification and their relation to gaze allocation remain under-reported. The present study utilized a within-subjects eye-tracking design to examine both accurate and inaccurate recognition of five basic emotions (anger, disgust, fear, happiness, and sadness) in healthy young adults. Fifty participants (twenty-four women) completed a forced-choice categorization task with 10 stimuli (female/male poser x emotion). A remote eye tracker (60 Hz) recorded fixations mapped to eyes, nose, and mouth areas of interest (AOIs). The analyses combined accuracy and decision-time statistics with heatmap comparisons of misclassified versus accurate trials within the same image. Overall accuracy was 87.8% (439/500). Misclassification patterns depended on the target emotion, but not on participant gender. Fear male was most often misclassified (typically as disgust), and sadness female was frequently labeled as fear or disgust; disgust was the most incorrectly attributed response. For accurate trials, decision time showed main effects of emotion (p < 0.001) and participant gender (p = 0.033): happiness was categorized fastest and anger slowest, and women responded faster overall, with particularly fast response times for sadness. The AOI results revealed strong main effects and an AOI x emotion interaction (p < 0.001): eyes received the most fixations, but fear drew relatively more mouth sampling and sadness more nose sampling. Crucially, heatmaps showed an upper-face bias (eye AOI) in inaccurate trials, whereas accurate trials retained eye sampling and added nose and mouth AOI coverage, which aligned with diagnostic cues. These findings indicate that the scanpath strategy, in addition to information availability, underpins success and failure in basic-emotion recognition, with implications for theory, targeted training, and affective technologies.Article Citation - WoS: 1Citation - Scopus: 4Fixed Point Theorems for Mappings With a Contractive Iterate at a Point in Modular Metric Spaces(House Book Science-casa Cartii Stiinta, 2022) Karapinar, Erdal; Aksoy, Umit; Fulga, Andreea; Erhan, Inci M.In this manuscript, we introduce two new types of contraction, namely, w-contraction and strong Sehgal w-contraction, in the framework of modular metric spaces. We indicate that under certain assumptions, such mappings possess a unique fixed point. For the sake of completeness, we consider examples and an application to matrix equations.Editorial Citation - WoS: 5Citation - Scopus: 5Transcatheter Treatment Tricuspid Regurgitation by Valve-In Implantation With a Novel Balloon-Expandable Myval® Thv(Polish Cardiac Soc-polskie Towarzystwo Kardiologiczne, 2022) Ayhan, Huseyin; Karaduman, Bilge Duran; Keles, Telat; Bozkurt, Engin[No Abstract Available]Article Citation - WoS: 3Citation - Scopus: 4Physical Fitness and Maternal Psychosocial Status in Children With Autism Attending a Regular Physical Activity Program(Sage Publications inc, 2022) Sahan, Ayse Kubra; Ozturk, Nazan; Calik-Kutukcu, Ebru; Aksu, Hatice; Tunagur, Mustafa Tolga; Arikan, HulyaThe aim of this study was to compare physical fitness-related parameters in children with mild to moderate autism and their typically developing (TD) peers to determine maternal anxiety level and quality of life. Children with autism had significantly worse scores for all Munich Fitness Test (MFT) parameters except step test heart rate and had lower physical activity levels compared to the TD children (p < .05). There was no difference between groups in terms of postural deviations or maternal anxiety scores (p > .05). The MFT total score was associated with higher maternal quality of life scores (r = .605, p = .006). This study showed that despite participating in a regular physical activity program, children with mild to moderate autism have lower physical fitness and activity levels compared to their TD peers, whereas better physical fitness in children with autism has a positive effect on their mothers' quality of life.Article Citation - WoS: 19Citation - Scopus: 18Best Proximity Point Theorems for kt-types Cyclic Orbital Contraction Mappings(House Book Science-casa Cartii Stiinta, 2012) Karapinar, Erdal; Petrusel, Gabriela; Tas, Kenan; MathematicsIn this manuscript, three new KT-types cyclic orbital contractions are defined and some related best proximity point theorems are given. Also, the notion of KT-type cyclic orbital Meir-Keeler contraction is defined and some fixed point theorems for this class of mappings are proved. The results of this manuscript generalize some theorems, on the same subject, of several authors, such as Kirk-Srinavasan-Veeramani, Eldered-Veeramani and Karpagam-Agrawal.Article Citation - WoS: 8Citation - Scopus: 8Thermoluminescence Properties of Zno Nanoparticles in the Temperature Range 10-300 K(Springer, 2016) Isik, M.; Yildirim, T.; Gasanly, N. M.Low-temperature thermoluminescence (TL) properties of ZnO nanoparticles grown by sol-gel method were investigated in the 10-300 K temperature range. TL glow curve obtained at 0.2 K/s constant heating rate exhibited one broad peak around 83 K. The observed peak was analyzed using curve fitting method to determine the activation energies of trapping center(s) responsible for glow curve. Analyses resulted in the presence of three peaks at 55, 85 and 118 K temperatures with activation energies of 12, 30 and 45 meV, respectively. Thermal cleaning process was applied to separate overlapped peaks and get an opportunity to increase the reliability of results obtained from curve fitting method. Heating rate dependence of glow curve was also studied for rates between 0.2 and 0.7 K/s. The shift of the peak maximum temperatures to higher values and decrease in peak height with heating rate were observed. Moreover, X-ray diffraction and scanning electron microscopy were used for structural characterization.Article Citation - WoS: 13Citation - Scopus: 13Coincidence Point Theorems on Quasi-Metric Spaces Via Simulation Functions and Applications To g-metric Spaces(Springer Basel Ag, 2018) Lopez de Hierro, A. F. Roldan; Karapinar, E.; O'Regan, D.In this paper, we present some coincidence point results in the framework of quasi-metric spaces using contractive conditions involving simulation functions. As consequences, we are able to particularize these results to a variety of situations including G-metric spaces. The results presented in this paper generalize and extend several comparable results in the existing literature. In addition, some examples are given.
