http://hdl.handle.net/20.500.12566/993 Wed, 08 Apr 2026 08:41:41 GMT 2026-04-08T08:41:41Z http://hdl.handle.net/20.500.12566/881 A comparative analysis of breast cancer detection and diagnosis using data visualization and machine learning applications Ak, Muhammet Fatih In the developing world, cancer death is one of the major problems for humankind. Even though there are many ways to prevent it before happening, some cancer types still do not have any treatment. One of the most common cancer types is breast cancer, and early diagnosis is the most important thing in its treatment. Accurate diagnosis is one of the most important processes in breast cancer treatment. In the literature, there are many studies about predicting the type of breast tumors. In this research paper, data about breast cancer tumors from Dr. William H. Walberg of the University of Wisconsin Hospital were used for making predictions on breast tumor types. Data visualization and machine learning techniques including logistic regression, k-nearest neighbors, support vector machine, naïve Bayes, decision tree, random forest, and rotation forest were applied to this dataset. R, Minitab, and Python were chosen to be applied to these machine learning techniques and visualization. The paper aimed to make a comparative analysis using data visualization and machine learning applications for breast cancer detection and diagnosis. Diagnostic performances of applications were comparable for detecting breast cancers. Data visualization and machine learning techniques can provide significant benefits and impact cancer detection in the decision-making process. In this paper, different machine learning and data mining techniques for the detection of breast cancer were proposed. Results obtained with the logistic regression model with all features included showed the highest classification accuracy (98.1%), and the proposed approach revealed the enhancement in accuracy performances. These results indicated the potential to open new opportunities in the detection of breast cancer. Wed, 01 Jan 2020 00:00:00 GMT http://hdl.handle.net/20.500.12566/881 2020-01-01T00:00:00Z http://hdl.handle.net/20.500.12566/877 Mathematical model of the ventricular action potential and effects of isoproterenol-induced cardiac hypertrophy in rats Şengül Ayan, Sevgi; Sırcan, Ahmet K.; Abewa, Mohamedou; Kurt, Ahmet; Dalaman, Uğur; Yaraş, Nazmi Mathematical action potential (AP) modeling is a well-established but still-developing area of research to better understand physiological and pathological processes. In particular, changes in AP mechanisms in the isoproterenol (ISO) -induced hypertrophic heart model are incompletely understood. Here we present a mathematical model of the rat AP based on recordings from rat ventricular myocytes. In our model, for the first time, all channel kinetics are defined with a single type of function that is simple and easy to apply. The model AP and channels dynamics are consistent with the APs recorded from rats for both Control (absence of ISO) and ISO-treated cases. Our mathematical model helps us to understand the reason for the prolongation in AP duration after ISO application while ISO treatment helps us to validate our mathematical model. We reveal that the smaller density and the slower gating kinetics of the transient K+ current help explain the prolonged AP duration after ISO treatment and the increasing amplitude of the rapid and the slow inward rectifier currents also contribute to this prolongation alongside the flux in Ca2+ currents. ISO induced an increase in the density of the Na+ current that can explain the faster upstroke. We believe that AP dynamics from rat ventricular myocytes can be reproduced very well with this mathematical model and that it provides a powerful tool for improved insights into the underlying dynamics of clinically important AP properties such as ISO application. Wed, 01 Jan 2020 00:00:00 GMT http://hdl.handle.net/20.500.12566/877 2020-01-01T00:00:00Z http://hdl.handle.net/20.500.12566/865 Sulfur dioxide derivative prevents the prolongation of action potential during the isoproterenol-induced hypertrophy of rat cardiomyocytes Dalaman, Uğur; Özdoğan, Hasan; Sırcan, Ahmet Kürşad; Şengül Ayan, Sevgi; Yaraş, Nazmi Exogenous SO2 is toxic especially to the pulmonary and cardiovascular system, similar to nitric-oxide, carbon-monoxide, and hydrogen-sulfide. Endogenous SO2 is produced in many cell types. The SO2 content of the rat heart has been observed to substantially decrease during isoproterenol-induced hypertrophy. This study sought to determine whether an SO2 derivative could inhibit the prolongation of action potentials during the isoproterenol-induced hypertrophy of rat cardiomyocytes and explore the ionic currents. Alongside electrocardiogram recordings, the voltage and current- clamped measurements were conducted in the enzymatically isolated left ventricular cardiomyocytes of Wistar rats. The consistency of the results was evaluated by the novel mathematical electrophysiology model. Our results show that SO2 significantly blocked the prolongation of QT-interval and action potential duration. Furthermore, SO2 did not substantially affect the Na+ currents and did not improve the decreased steady- state and transient outward K+ currents, but it reverted the reduced L-type Ca2+ currents (ICaL) to the physiological levels. Altered inactivation of ICaL was remarkably recovered by SO2. Interestingly, SO2 significantly increased the Ca2+ transients in hypertrophic rat hearts. Our mathematical model also confirmed the mechanism of the SO2 effect. Our findings suggest that the shortening mechanism of SO2 is related to the Ca2+ dependent inactivation kinetics of the Ca2+ current. Fri, 01 Jan 2021 00:00:00 GMT http://hdl.handle.net/20.500.12566/865 2021-01-01T00:00:00Z http://hdl.handle.net/20.500.12566/844 Lymphedema information and prevention practices of women after breast cancer surgery Aydın, Aydanur; Gürsoy, Ayla AIM: This study was carried out to determine women’s knowledge about lymphedema precautions and their practice status. The sample of this descriptive and correlationally designed study included 107 women who underwent surgery. METHOD: This descriptive study’s data were collected using a questionnaire form developed by the researcher. The data were structured on a 3-point Likert-type scale. The one-way analysis of variance, correlations, and the Kolmogorov–Smirnov test were used in the statistical analysis. RESULTS: Three-quarters of the women knew that they should do arm exercises, keep the arm above the heart level while resting, and that blood pressure should not be measured, and jewelry not be worn. However, it was found that the percentage of women who did not know that the arm circumference should be measured at regular intervals or how to evaluate the arm circumference measurements and what to do in case of an injury was the same. It was determined that the precautions that the majority of women took in measuring lymphedema consisted of not measuring blood pressure, not wearing tight jewelry, and wearing an appropriate bra. CONCLUSION: It is thought that patients should be informed about the development of lymphedema after breast cancer surgery because their compliance with taking the precautions will be important in reducing the incidence, degree, and effects of lymphedema. Wed, 01 Jan 2020 00:00:00 GMT http://hdl.handle.net/20.500.12566/844 2020-01-01T00:00:00Z