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Öğe Could DTI unlock the mystery of subjective tinnitus: it's time for parameters that go a little out of the routine(Springer, 2024) Yılmaz, Eren; Yıldırım, Düzgün; Tekcan Şanlı, Deniz Esin; Elpen, Pınar; Gösterişli Tüzüner, Filiz; Gökmen İnan, Neslihan; Şirin, Ahmet; Yağımlı, Mustafa; Tozan, Hakan; Şanlı, Ahmet Necati; Kandemirli, Sedat GirayIn this study, it was aimed to assess the microstructural changes in the main central auditory pathway in cases with subjective tinnitus. In total, 101 subjects (52 cases with bilateral subjective non-pulsatile tinnitus and 49 healthy cases as the control group) were included in the study. Participants underwent pure tone audiogram and Diffusion Tensor Imaging-Magnetic Resonance Imaging (DTI-MRI) examination with a 3 Tesla MRI device. The number of tracts, tract length, volume, and quantitative anisotropy (QA) and normalized quantitative anisotropy' (nQA) values were calculated by plotting cochleocortical pathways from the cochlear nerve to ipsilateral and contralateral Heschl's gyrus (HG). In pure tone audiometry, the control group had lower hearing thresholds than cases with tinnitus. Fibres and nQA values from the right cochlear nerve to the right HG were significantly lower in the tinnitus group than in the control group. Cochlear nuclei voxel counts were significantly decreased in the tinnitus group. Both cochlear nucleus volumes were higher in the tinnitus group than in the control group. nQA values in both cochlear nuclei were decreased in the tinnitus group. This study showed that the most commonly affected part in subjective non-pulsatile tinnitus cases is the cochlear nucleus. Therefore, the cochlear nucleus should be evaluated more carefully in cases presenting with subjective tinnitus.Öğe Investigation of the network made with the complementary motor of the thalamus with the DTI method in individuals with tinnitus(Kare Publishing, 2024) Elpen Karyemez, Pınar; Yağımlı, Mustafa; Tozan, HakanObjectives:This This study aimed to investigate the differences in the networks between the thalamus and the supplementary motor area in brain MRI examinations of individuals with subjective chronic tinnitus and healthy control groups. Methods: In the study, brain MRI imaging was performed on 47 patients suffering from bilateral tinnitus for two years or more and 42 healthy individuals. The tensor information obtained using the diffusion tensor imaging sequence data obtained from both groups was processed in the DSI Studio program. Brain connection maps were obtained from the data obtained. Quantitative information of the individual connecogram maps of each case was recorded and the groups were compared. Results: In the tinnitus group, there is an increase in the pathways between the thalamus and the supplementary motor area. In addition, it was determined that the pathways of the thalamus with the hippocampus, superior and middle occipital area and frontal area increased, and the pathways with the hippocampus and cerebellum decreased. Conclusion: Important functions of the supplementary motor area and thalamus; These are cognitive actions in which attention plays an important role, such as noticing the stimulus from the environment, planning and implementing the response action. It is thought that changes in the pathways between the thalamus and the supplementary motor area will especially affect attention-related functions.Öğe Mathematical modelling of sound transmission loss performances of different coloured surfaces coated with polyurethane-based paint(Taylor & Francis Ltd, 2020) Ergin Esen, Hande; Yağımlı, Mustafa; Tozan, Hakan; Yalçın, G. E.; Arca, EminThe aim of this study is to investigate the effect of morphologies and the structure of polyurethane-based coatings created by different colour pigments, on sound transmission loss properties. To achieve this goal, coatings were created in different concentrations of 5%, 7% and 9% with red, green, orange and yellow pigments. The coatings were applied on glass surfaces and the sound transmission loss was measured by an experimental arrangement containing a microphone and a decibel meter. The effect of surface tension energy, surface roughness, reflection percentages and concentration of pigments were found to be negligible on the sound transmission loss, whereas the LAB colour codes have a determining effect. In the scope of this study, a new method and mathematical model were created to help measure the sound transmission loss on a surface, in which sound signal was carried with a laser beamviaa system created in the laboratory.Öğe Nötron radyasyondan korunmak için bor katkılı yüzey kaplaması oluşturulması ve karakterizasyonu(Gazi Üniversitesi, 2024) Seval, Hakan Kemal; Yağımlı, Mustafa; Tozan, HakanRadyasyon günlük hayat da sıklıkla maruz kaldığımız, iş sağlığı ve güvenliğinde de fiziksel risk etmenlerinden birini oluşturan tehlikedir. Sanayi sektöründe, enerji, araştırma ve tıbbi uygulamalarda iyonlaştırıcı radyasyon kaynakları yaygın olarak kullanılmaktadır. Özellikle bu sektörlerde çalışanlar radyasyona maruz kalmakta ve bunun sonucunda kanser başta olmak üzere birçok sağlık sorunu ile karşılaşmaktadır. Bu çalışma da hegzagonal bor nitrür (h-BN) katkı malzemesinin polivinil bütiral (PVB) ile fizikokimyasal süreçlerle ilave edilerek bor katkılı yüzey kaplama malzemesi geliştirilmiş ve daldırma kaplama yöntemi ile çelik üzerinde biriktirilmiştir. PVB kaplamadaki h-BN miktarının termal nötron radyasyonuna karşı koruyucu etkisi araştırılmıştır. Kaplama malzemelerinin moleküller arasında kovalent olmayan etkileşim sonucunda homojen bir dağılım gösterdiği görülmüştür. Katkı malzemesi h-BN ve oluşturulan kaplamalar XRD ve SEM ile karakterize edilmiştir. Üretilen kaplamaların nötron radyasyonuna karşı zırhlama özelliklerinin tespiti için nötron zayıflama deneyleri gerçekleştirilmiş ve termal nötron soğurma katsayısı (ΣT, makroskopik tesir kesiti) hesaplanmıştır. Tüm kaplamaların farklı oranlarda termal nötron radyasyonu azalttığı görülmüştür. En fazla nötron emilim doz oranı %48,42 olmuştur. Oluşturulan kaplama malzemesinin hem çevre hem insan sağlığı açısından toksik özellikte olmaması ve her yüzeye uygulanabilen zırh malzemesi olması amaçlanmıştır.Öğe The time response analysis of a hybrid electronic switch and residual current devices system(University of Osijek, 2024) Yurtçu, Ahmet; Yağımlı, Mustafa; Tozan, HakanResidual current devices are vital as they are used to protect humans from electric shocks and fire hazards. These devices detect the residual current in the grid, open the mechanism, and leave the grid without voltage. In this study, the time response of a newly designed hybrid system consisting of an electronic switch system and a residual current device to protect humans from hazards has been analyzed. A model consisting of capacitors and resistors has been used to simulate the human body. In the designed system, the average response time was found to be 1.37 ms, which operates with an average of 6.43 times faster than a conventional residual current device. The results of the study illustrated that the designed system leaves the circuit voltage-free much faster than a conventional residual current device and is more effective in protecting human life.
