https://hdl.handle.net/20.500.12294/2895 Tıbbi Görüntüleme Teknikleri Programına ait makaleler bu koleksiyonda listelenir. 2026-04-17T00:25:06Z https://hdl.handle.net/20.500.12294/4127 37 years after the chernobyl Gunay, Osman; Yalcin, Caner; Guray, R. Taygun; Karakurt, Didem Avci; Tantoglu, Ezgi; Basdemir, Safa This study aims to assess the artificial and natural radiation dose levels in certain districts of Kocaeli province within the Marmara region, 37 years after the Chernobyl nuclear accident, and evaluate the current status prior to potential nuclear leakage events from Zaporijya or other nuclear power plants. Radioactive concentrations of Th-232, U-238, K-40 and Cs-137 were determined using HPGe gamma spectrometry in 26 soil samples collected from the region of interest. The average concentrations were found to be 22.35 Bqkg(-1) for U-238, 26.36 Bqkg(-1) for Th-232, 368.34 Bqkg(-1) for K-40, and 2.44 Bqkg(-1) for Cs-137. Furthermore, the study revealed an absorbed dose rate of 41.73 nGyh(-1), an annual effective dose equivalent of 51.18 mu Svy(-1), and an excess lifetime cancer risk of 0.00018. 2024-01-01T00:00:00Z https://hdl.handle.net/20.500.12294/3907 Temporal evolution of entropy and chaos in low amplitude seismic wave prior to an earthquake Yılmaz, Nazmi; Akıllı, Mahmut; Ak, Mine This study investigates the temporal changes of entropy and chaos in low-amplitude continuous seismic wave data prior to two moderate-level earthquakes. Specifically, we examine seismic signals before and during the Istanbul-Turkey earthquake of September 26, 2019 (M = 5.7), and the Duzce-Turkey earthquake of November 17, 2021 (M = 5.2), which occurred near the Marmara Sea region on the north-Anatolian fault line. We aim to identify changes in complexity and chaotic characteristics in the pre-earthquake seismic waves and explore the possibility of earthquake forecasting minutes before an earthquake. To accomplish this, we utilize windowed scalogram entropy and sample entropy methods and compared the results with Lyapunov exponents and windowed scale index. Our findings indicate that measuring the temporal change of entropy using windowed scalogram entropy is sensitive to the change in complexity due to the frequency shifts during the weak ground motion approaching an earthquake. On the other hand, Lyapunov exponents and sample entropy appear more effective in their response to the change in complexity and chaotic characteristics due to the change in the signal amplitude. Additionally, the windowed scale index can detect temporal fluctuations in the aperiodicity of the signal. Overall, our results suggest that all four methods can be valuable in characterizing complexity and chaos in short-time pre-earthquake seismic signals, differentiating earthquakes, and contributing to the development of earthquake forecasting techniques. © 2023 Elsevier Ltd 2023-01-01T00:00:00Z https://hdl.handle.net/20.500.12294/3875 Determination of the effect of silica nanoparticles on TRP currents in retinal pigment epithelial cells by entropy measurement Sogut, Fatma; Akilli, Mahmut; Kaynar, Ayse Humeyra; Tuncel, Handan; Kibar, Deniz; Yilmaz, Sakir Necat; Comelekoglu, Ulku Ion channels in cell membranes are gated, water-filled pores that allow passive transport of ions across the membrane along their electrochemical gradient. Recent studies have shown that nanoparticles can interact with ion channels and change their currents kinetics properties of the channel. In this study, we used the transient receptor potential (TRP) channel currents in retinal pigment epithelial (RPE) cells recorded by whole-cell patch clamp technique to observe the silica nanoparticle-ion channel interaction. For whole cell recordings, we clamped membrane potential to − 40 mV and used a ramp of 1000 ms duration for stimulation. The ramp was increased from − 140 mV to +60 mV. We used windowed scalogram entropy and compared the results with windowed scale index method. Our results indicated that the temporal change of entropy using windowed scalogram entropy method is sensitive to demonstrating the effect of silica nanoparticles on RPE cell TRP currents. Furthermore, windowed scale index can analyze the temporal fluctuations in the aperiodicity of cell membrane current signals. Our findings suggest that entropy measurement methods may be useful in the function analysis of cell ion channels. 2023-01-01T00:00:00Z https://hdl.handle.net/20.500.12294/3863 Acute effect of kinesiotaping applied to the first finger of the patients with rheumatoid hand Narin, Selnur; Bayraktar, Dilek; Ozgul, Semiha; Inal, Vedat; Çöpüroğlu, Özge Baykan Background & Objective: Rheumatoid arthritis (RA) is a crippling disease characterized by joint pains and joint stiffness. Kinesiotaping (KT) has been advocated to reduce local pressure and increase circulation, resulting in decreased pain in various conditions. We aimed to evaluate the acute effect of KT on pain, function, range of motion (ROM) and grip strength parameters in patients with rheumatoid hand. Methodology: A total of 34 patients, 27 women and 7 men, diagnosed with RA were included in our study. All patients were divided into two groups; Kinesiotape group (Group KT) and control group (Group C), each consisting of 17 patients. Subjective pain intensity by Visual Analog Scale (VAS), ROM by goniometer, functional evaluation with the Grip Skill Test, hand grip strength by dynamometer, and finger grip strength by pinchmeter were evaluated. The patients in the Group KT were taped with the mechanical correction method and the patients in the Group C were taped with tensionless I tape. Applications were made on both dominant and non-dominant hands. Results: The mean age of the patients was 54 +/- 20 y. VAS score changes at the time of grasping were significant in both groups (P < 0.05), but Group KT was more effective for reducing pain and increasing grip strength. An increase was observed in the wrist and thumb metacarpophalangeal joint ROM in the Group KT (P < 0.05). No change was observed in the groups in hand grip strength and finger grip strength (P > 0.05). In the Grip Skill test, there was a significant difference after the application in both groups (P < 0.05), but there was no difference in between the groups (P > 0.05). Conclusion: Kinesiotaping applied in rheumatoid hand patients was found to be effective in increasing functionality and joint range of motion, as well as reducing pain during gripping. 2023-01-01T00:00:00Z