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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 Citation - WoS: 11Citation - Scopus: 14Card Spending Dynamics in Turkey During the Covid-19 Pandemic(Central Bank Republic Turkey, 2021) Kantur, Zeynep; Özcan, GülserimThis paper provides an extensive analysis of card spending during the COVID-19 pandemic in Turkey by using weekly aggregated and sectoral credit and debit card spending data from March 2014 to December 2020. At an aggregated level, we show that aggregate demand decreases significantly at the early stages of COVID-19 and seems to reinstate its pre-COVID trend. However, when we include the pre-existing conditions of Turkey, the 2018 currency crisis, we observe that the recovery in demand is not that strong. To highlight the underlying reasons for structural change in aggregate demand, we estimate the model with stringency index and unemployment-related search index. The estimated model indicates that containment measures and restrictions and fear of job/income loss mainly explain the overall impact of COVID-19 on aggregate demand. We also examined sectoral data to understand aggregate demand dynamics better. Only stable and delayable sector groups have reached a trend above their pre-pandemic trajectories. However, the social and work-related sectors are far from their respective pre-pandemic trend.Article 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: 1Citation - Scopus: 1Karotis Arter Stentlemesinin Etkinliği ve Güvenliği: Tek Merkez Deneyimi(Kare Publ, 2020) Karaduman, Bilge Duran; Karaduman, Bilge Duran; Ayhan, Hüseyin; Ayhan, Hüseyin; Keles, Telat; Bozkurt, Engin; Karaduman, Bilge Duran; Ayhan, HüseyinAmaç: İnternal karotis arterdeki orta ve şiddetli darlıklar tüm inmelerin %10–15’ine neden olmaktadır. Bu çalışmada, üçüncü basamak bir referans merkezde karotis arter stentlemesinin (KAS) güvenliğini ve kısa dönem etkinliğini değerlendirmeyi amaçladık. Yöntemler: Üçüncü basamak merkezimizde Ocak 2017 ile Mayıs 2018 arasında KAS uygulanan hastalar geriye dönük olarak değerlendirildi. KAS uygulanan 145 hasta çalışmaya dahil edildi. Bulgular: Hastaların ortalama yaşı 70.1±8.6 yıl idi ve tüm grubun %75.2’si erkek olup %37.9’unda hipertansiyon mevcuttu. Hastaların 81’i (%55.9) semptomatik, 64’ü (%44.1) asemptomatik olarak gruplandırıldı. Semptomatik hastalarda koroner girişimler daha çok KAS sonrası (%38.9) yapılırken, asemptomatik grupta ise KAS öncesi (%25.9) ve sonrasında (%25.9) benzer oranlarda yapıldığı görüldü ama gruplar arasında istatistiksel fark yoktu. Semptomatik hastalarda (%59.2), asemptomatik hastalarda (%78.7) olduğu gibi distal emboli koruyucu cihaz (EKC), proksimal EKC’ye göre daha fazla kullanıldı. Ancak proksimal EKC, semptomatik hastalarda asemptomatik hastalara kıyasla anlamlı olarak daha fazla kullanıldı. Hastane içi ölüm görülmedi ve tüm popülasyonda 5 (%3.4) hastada inme veya geçici iskemik atak (GİA) gözlendi. Asemptomatik grupta GİA veya inme gözlenmedi, semptomatik grupta 2 hastada (%2.4) inme ve 3 hastada (%3.7) GİA görüldü. Sonuç: Bu çalışma kabul edilebilir komplikasyon oranları ile KAS’ın güvenirliğini ve uygulanabilirliğini ortaya koymuştur. KAS prosedürü, deneyimli girişimciler tarafından optimal tıbbi tedavi altında, agresif risk modifikasyonu ile EKC kullanılarak, uygun hastalarda en az komplikasyonla gerçekleştirilmelidir.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: 21Citation - Scopus: 23Fear of Missing Out, Internet Addiction and Their Relationship To Psychological Symptoms(Turkish Green Crescent Soc, 2020) Orta, İrem Metin; Metin-Orta, IremInternet addiction has become one of the most important problems of today's youth and received considerableattention from scholars. Research demonstrated significant impairments in psychological and social functioning among internet dependents. Given this, the present study aimed to investigate the relationship betweenfear of missing out (FoMO), internet addiction, and psychological symptoms. Based on research demonstratingthat FoMO, the pervasive anxiety associated with the feeling that one is missing out others’ satisfying experiences, increases social media engagement, it was expected that FoMO would relate to internet addiction, whichin turn would be linked to poor psychological well-being. The sample consisted of 322 undergraduate studentswho filled out items measuring FoMO, internet addiction and psychological symptoms. The regression analysisrevealed that internet addiction acts as a mediator in the link between FoMO and psychological symptoms.That is, the participants’ greater FoMO is linked to higher levels of psychological symptoms both directly andindirectly through a higher level of internet addiction. Overall, the present study provides an insight into ourunderstanding of the psychological and behavioral aspects of internet addiction, and thus, makes an importantcontribution to the promotion of mental health.Article Correlation of Clinical Signs and Magnetic Resonance Imaging Findings in Patients With Lumbar Spondylosis(Turkish League Against Rheumatism, 2023) Altan, Lale; Ökmen, Burcu Metin; Tuncer, Tiraje; Sindel, Dilşad; Çay, Hasan Fatih; Hepgüler, Simin; Uğurlu, Hatice; Gurer, Gülcan; Sarıkaya, Selda; Melikoğlu, Meltem Alkan; Metin Ökmen, Burcu; Ayhan, Fikriye Figen; Duruöz, Mehmet Tuncay; Sezer, IlhanObjectives: The purpose of the study was to contribute further to this debated topic by investigating the correlation of magnetic resonance imaging (MRI) findings with the clinical picture in lumbar spondylosis patients. Patients and methods: This multicenter retrospective study (as part of the epidemiological project of the TLAR-OASG [Turkish League Against Rheumatism-Osteoarthritis Study Group]) included 514 patients (101 males, 413 females; mean age: 63.6±10.8 years; range, 40 to 85 years) who were diagnosed as lumbar spondylosis by clinical examination and direct X-ray between December 2016 and June 2018. Demographic characteristics of patients, Visual Analog Scale for pain, presence of radiating pain, Roland-Morris disability questionnaire, straight leg raise test, deep tendon reflexes, neurogenic intermittent claudication symptoms, any decrease of muscle strength, and abnormality of sensation were recorded. Lumbar MRI findings of the patients were recorded as positive or negative in terms of disc herniation, intervertebral disc degeneration, root compression, osteophytes, spinal stenosis. Statistical analysis was done to assess the correlation between the clinical symptoms, physical examination, and MRI findings. Results: Correlation analysis of the MRI results and the clinical findings showed a significant correlation between straight leg raise test and root compression (p<0.001, r=0.328) and a significant correlation between neurogenic intermittent claudication and spinal stenosis (p<0.001, r=0.376). Roland-Morris disability questionnaire had a significant correlation with all MRI findings (p<0.05, r<0.200). Conclusion: The results of this study corroborate the notion that diligent patient history and physical examination are more valuable than MRI findings, even though a higher incidence of abnormal MRI findings have been obtained in patients with disability and dermatomal radiating pain.Article A Modeling Approach for Designing New Acoustic Materials(Gazi Univ, 2024) Koçyiğit, Filiz Bal; Köse, Ercan; Buluklu, Hatice Mehtap; Bal Kocyigit, FilizIn this study, mathematical modeling design based on Sound Transmission Loss measurement results of new acoustic material samples with natural content was carried out. Using the test samples in question, transfer function of acoustic materials based on electronic filter circuit design and a transition design method for the production of new acoustic materials by utilizing the transfer function is presented. Based on the experimental results of the test samples, it is the most suitable low-pass filter structure for the proposed design. In this study, active Sallen-Key low-pass filter structure is preferred and used. Sound Transmission Losses in dB (decibels) of acoustic samples were obtained experimentally for 500, 1000, 2000 and 4000 Hz. fundamental frequencies in the literature. Based on these data, transfer function simulation suppression gain results were obtained in TINA-TI program, active filter circuit designed, and MATLAB program. When the other results were compared in the experimental results, it was seen that very close values were obtained. It has been demonstrated that the proposed method can be used effectively in the design and examination of new acoustic materials.Article Citation - WoS: 4Citation - Scopus: 516s Bacterial Metagenomic Analysis of Herby Cheese (otlu Peynir) Microbiota(Istanbul Univ-cerrahpasa, 2021) Sudağıdan, Mert; Yurt, Mediha Nur Zafer; Taşbaşı, Behiye Büşra; Acar, Elif Esma; Ömeroğlu, Esra Ersoy; Uçak, Samet; Aydın, Ali; Ozalp, Cengiz; Ersoy Omeroglu, Esra; Mediha Nur, Zafer YURTCheese microbiota may contain various bacterial species due to the use of different types of milk, rennet, and herbs. In this study, the distribution of the dominant bacteria present in the microbiota of herby cheese samples (n = 13) were examined by the next generation sequencing (NGS) technique. DNA was extracted both directly from cheese samples and after pre-enrichment. The metagenomic analysis of the NGS results revealed that Firmicutes were dominant both in DNA directly extracted from herby cheese (KOP), and pre-enriched samples (OP), at the phylum level. At the genus level, Lactobacillus, Lactococcus, and Streptococcus were dominant in the KOP samples, whereas in the OP samples, Enterococcus, Streptococcus, and Bacillus were determined as the dominant bacterial genera. Although Lactococcus raffinolactis and Streptococcus salivarius were dominant in the KOP samples, Enterococcus faecalis and S. salivarius were dominant in the OP samples. The Shannon species diversity index and principal coordinates analysis (PCoA) were used to determine the distribution in KOP and OP samples at the genus level. The PCoA of KOP-10, KOP-11, KOP-2, and KOP-7, KOP-3, and KOP-6 samples showed the wide distribution, whereas KOP-5, KOP-8, KOP-9, and KOP-14 herby cheese samples were closely related. The OP samples, especially OP-7 and OP-14, showed wide distribution in comparison to other OP samples. Finally, the dominant bacterial communities were identified by DNAbased metagenomic analysis, and this is the first report to elucidate the microbiota of herby cheese produced in Turkey using the NGS technique.
