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Article ISAR Imaging of Drone Swarms at 77 GHz(Tubitak Scientific & Technological Research Council Turkey, 2025) Coruk, Remziye Busra; Kara, Ali; Aydin, ElifThe proliferation of easily available, internet-purchased drones, coupled with the emergence of coordinated drone swarms, poses a significant security threat for airspace. Detecting these swarms is crucial to prevent potential accidents, criminal misuse, and airspace disruptions. This paper proposes a novel inverse synthetic aperture radar (ISAR) imaging technique for high-resolution reconstruction of drone swarms at 77 GHz millimeter wave (mmWave) frequency, offering a valuable tool for military and defense antidrone systems. The key parameters affecting down-range and cross-range resolution (0.05 m), ultimately enabling the generation of detailed ISAR images are discussed. Here, we create diverse scenarios encompassing various swarm formations, sizes, and payload configurations by employing ANSYS simulations. To enhance image quality, different window functions are evaluated, and the Hamming window is selected due to its highest peak signal-to-noise ratio (PSNR) (16.3645) and structural similarity (SSIM) (0.9067) values, ensuring superior noise reduction and structural preservation. The results demonstrate that the effectiveness of high-resolution ISAR imaging in accurately detecting and characterizing drone swarms pave the way for enhanced airspace security measures.Article Citation - WoS: 1Citation - Scopus: 1Solving an initial boundary value problem on the semiinfinite interval(Tubitak Scientific & Technological Research Council Turkey, 2016) Atalan, Ferihe; Guseinov, Gusein Sh.We explore the sign properties of eigenvalues and the basis properties of eigenvectors for a special quadratic matrix polynomial and use the results obtained to solve the corresponding linear system of differential equations on the half line subject to an initial condition at t = 0 and a condition at t = infinity.Article Citation - WoS: 1Citation - Scopus: 1Short-Term Effectiveness of Epidermis Dermis Fascia Kinesiotaping Technique in Myofascial Pain Syndrome on Upper Trapezius: a Multi-Center, Double-Blind, Randomized Clinical Study(Baycinar Medical Publ-Baycinar Tibbi Yayincilik, 2024) Ayhan, Fikriye Figen; Külcü, Duygu Geler; Keleş, Elif Çiğdem; Dinç, Arzu; Mesci, Nilgün; Çakmak, Bahar; Yılmaz, Zeynep Alpoğuz; Erhan, Belgin; Yavas, Arzu Ding; Kölcö, Duygu Geler; Tur, Birkan SonelObjectives: This study aims to investigate the efficacy of epidermis dermis fascia (EDF) kinesiotaping (KT) technique on pain intensity, number of active trigger points (TrPs), cervical range of motion (ROM) angles, and disability levels in patients with myofascial pain syndrome (MPS) on upper trapezius (UT) muscle. Patients and methods: Between January 2019 and January 2020, a total of 180 patients (21 males, 159 females; mean age: 35.9±9.0 years; range, 18 to 56 years) with MPS were included. The patients were randomized into either KT with EDF technique (Group 1) or sham KT (Group 2). Outcome measures were Visual Analog Scale (VAS) pain score, number of active TrPs, cervical ROM angles, and Neck Pain Disability Scale (NPDS). Results: Both groups improved in terms of all outcome parameters except for cervical flexion and extension angles in Group 2. The VAS pain scores significantly decreased in Group 1 (p<0.05), compared to Group 2. The number of active TrPs (p=0.001) and NPDS scores (p=0.016) of Group 1 significantly improved than Group 2. Cervical flexion (p=0.001), extension (p=0.001), and left and right lateral flexion angles (p<0.0001) significantly improved in Group 1. Cervical left (p=0.001) and right (p<0.0001) lateral flexion angles significantly improved in Group 2. There was no significant difference between the groups regarding cervical ROM angles. Conclusion: Our study results suggest that KT with the EDF technique is an effective method in reducing pain and number of active TrPs, improving disability and cervical ROM angles.Article A Note on the Generalized Matsumoto Relation(2017) Dalyan, Elif; Medetoğulları, Elif; Pamuk, MehmetcikWe give an elementary proof of a relation, first discovered in its full generality by Korkmaz, in the mapping class group of a closed orientable surface. Our proof uses only the well-known relations between Dehn twists.Article Citation - WoS: 3Citation - Scopus: 3A Note on the Generalized Matsumoto Relation(Tubitak Scientific & Technological Research Council Turkey, 2017) Dalyan, Elif; Medetogullari, Elif; Pamuk, MehmetcikWe give an elementary proof of a relation, first discovered in its full generality by Korkmaz, in the mapping class group of a closed orientable surface. Our proof uses only the well-known relations between Dehn twists.Article Citation - WoS: 3Citation - Scopus: 5Investigation of the Effect of Hyperthyroidism on Endoplasmic Reticulum Stress and Transient Receptor Potential Canonical 1 Channel in the Kidney(Tubitak Scientific & Technological Research Council Turkey, 2021) Aykanat, Nuriye Ezgi Bektur; Şahin, Erhan; Kaçar, Sedat; Bağcı, Rıdvan; Karakaya, Şerife; Dönmez, Dilek Burukoğlu; Şahintürk, Varol; Bektur Aykanat, Nuriye Ezgi; Burukoğlu Dönmez, Dilek; Bektur, EzgiBackground/aim: Hyperthyroidism is associated with results in increased glomerular filtration rate as well as increased renin-angiotensin-aldosterone activation. The disturbance of Ca2+ homeostasis in the endoplasmic reticulum (ER) is associated with many diseases, including diabetic nephropathy and hyperthyroidism. Transient receptor potential canonical 1 (TRPC1) channel is the first cloned TRPC family protein. Although it is expressed in many places in the kidney, its function is uncertain. TRPC1 is involved in regulating Ca2+ homeostasis, and its upregulation increases ER Ca2+ level, activates the unfolded protein response, which leads to cellular damage in the kidney. This study investigated the role of TRPC1 in the kidneys of hyperthyroid rats in terms of ER stress markers that are glucose-regulated protein 78 (GRP78), activating transcription factor 6 (ATF6), (protein kinase R (PKR)-like endoplasmic reticulum kinase) (PERK), Inositol-requiring enzyme 1 (IRE1). Materials and methods: Twenty male rats were assigned into control and hyperthyroid groups (n = 10). Hyperthyroidism was induced by adding 12 mg/L thyroxine into the drinking water of rats for 4 weeks. The serum-free T3 and T4 (fT3, fT4), TSH, blood urea nitrogen (BUN), and creatinine levels were measured. The histochemical analysis of kidney sections for morphological changes and also immunohistochemical and western blot analysis of kidney sections were performed for GRP78, ATF6, PERK, IRE1, TRPC1 antibodies. Results: TSH, BUN, and creatinine levels decreased while fT3 and fT4 levels increased in the hyperthyroid rat. The morphologic analysis resulted in the capillary basal membrane thickening in glomeruli and also western blot, and immunohistochemical results showed an increase in TRPC1, GRP78, and ATF6 in the hyperthyroid rat (p < 0.05). Conclusion: In conclusion, in our study, we showed for the first time that the relationship between ER stress and TRPC1, and their increased expression caused renal damage in hyperthyroid rats.Key words: Hyperthyroidism, endoplasmic reticulum (ER) stress, transient receptor potential canonical 1 (TRPC1), kidney, ratArticle Fedja’s Proof of Deepti’s Inequality(Tubitak Scientific & Technological Research Council Turkey, 2018) Ostrovska, Sofiya; Turan, MehmetThe paper aims to present, in a systematic way, an elegant proof of Deepti’s inequality. Both the inequalityand various ideas concerning the issue were discussed on the Mathoverflow website by a number of users, but none haveappeared in the literature thus far. In this work, suggestions pertaining to users ‘Deepti’ and ‘fedja’ are traced, whencethe title. The results or the paper are new, and the proof is divided into a series of statements, many of which are ofinterest in themselves.Article Citation - WoS: 9Citation - Scopus: 10Impact of Hospital-Acquired Acute Kidney Injury on Covid-19 Outcomes in Patients With and Without Chronic Kidney Disease: a Multicenter Retrospective Cohort Study(Tubitak Scientific & Technological Research Council Turkey, 2021) Ozturk, Savas; Turgutalp, Kenan; Arıcı, Mustafa; Çetinkaya, Hakkı; Altıparmak, Mehmet Rıza; Aydın, Zeki; Ateş, Kenan; Dolarslan, Mursıde Esra; Seyahi, Nurhan; Yıldız, Alaattın; Bora, FeyzaBackground/aim: Hospital-acquired acute kidney injury (HA-AKI) may commonly develop in Covid-19 patients and is expected to have higher mortality. There is little comparative data investigating the effect of HA-AKI on mortality of chronic kidney disease (CKD) patients and a control group of general population suffering from Covid-19. Materials and methods: HA-AKI development was assessed in a group of stage 3–5 CKD patients and control group without CKD among adult patients hospitalized for Covid-19. The role of AKI development on the outcome (in-hospital mortality and admission to the intensive care unit [ICU]) of patients with and without CKD was compared. Results: Among 621 hospitalized patients (age 60 [IQR: 47–73]), women: 44.1%), AKI developed in 32.5% of the patients, as stage 1 in 84.2%, stage 2 in 8.4%, and stage 3 in 7.4%. AKI developed in 48.0 % of CKD patients, whereas it developed in 17.6% of patients without CKD. CKD patients with HA-AKI had the highest mortality rate of 41.1% compared to 14.3% of patients with HA-AKI but no CKD (p < 0.001). However, patients with AKI+non-CKD had similar rates of ICU admission, mechanical ventilation, and death rate to patients with CKD without AKI. Adjusted mortality risks of the AKI+non-CKD group (HR: 9.0, 95% CI: 1.9–44.2) and AKI+CKD group (HR: 7.9, 95% CI: 1.9–33.3) were significantly higher than that of the non-AKI+non-CKD group. Conclusion: AKI frequently develops in hospitalized patients due to Covid-19 and is associated with high mortality. HA-AKI has worse outcomes whether it develops in patients with or without CKD, but the worst outcome was seen in AKI+CKD patients.Key words: Acute kidney injury, chronic kidney disease, Covid-19, hospitalization, mortalityArticle Characterizations of the Commutators Involving Idempotents in Certain Subrings of $m_{2}(\mathbb{z})$(Tubitak Scientific & Technological Research Council Turkey, 2023) Ozdin, Tufan; Gumusel, GunseliIn this paper, we characterize the idempotency, cleanness, and unit-regularity of the commutator [E1, E2] = E1E2 - E2E1 involving idempotents E1, E2 in certain subrings of M2(Z).Article Neuron Modeling: Estimating the Parameters of a Neuron Model From Neural Spiking Data(Tubitak Scientific & Technological Research Council Turkey, 2018) Doruk, Resat Ozgur; Doruk, OzgurWe present a modeling study aiming at the estimation of the parameters of a single neuron model from neural spiking data. The model receives a stimulus as input and provides the firing rate of the neuron as output. The neural spiking data will be obtained from point process simulation. The resultant data will be used in parameter estimation based on the inhomogeneous Poisson maximum likelihood method. The model will be stimulated by various forms of stimuli, which are modeled by a Fourier series (FS), exponential functions, and radial basis functions (RBFs). Tabulated results presenting cases with different sample sizes (# of repeated trials), stimulus component sizes (FS and RBF), amplitudes, and frequency ranges (FS) will be presented to validate the approach and provide a means of comparison. The results showed that regardless of the stimulus type, the most effective parameter on the estimation performance appears to be the sample size. In addition, the lowest variance of the estimates is obtained when a Fourier series stimulus is applied in the estimation.
