Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Repair and Strengthening of Fire Damaged Concrete Cylinders Using FRP Confinement: Tests and Analytical Modelling(Elsevier Science inc, 2025) Demir, Ugur; Ilki, AlperThis study examines the effects of fiber-reinforced polymer (FRP) repair and strengthening on the axial stress-strain behavior of concrete columns after exposure to realistic fires. A total of 30 plain concrete cylinders, each measuring 150 x 300 mm, were cast for this investigation. Of these, three specimens were kept as reference at ambient temperature, while the remaining were exposed to ISO-834 standard fire for durations of 30, 60 or 90 min, with nine specimens in each duration group. After natural cooling, the heated specimens were categorized into three groups: i) three were left unconfined, ii) three were repaired and strengthened using two layers of carbon FRP sheets, and iii) three were repaired and strengthened with four layers of carbon FRP sheets. This study employs realistic ISO 834 fire scenarios and investigates CFRP confinement with up to four layers, addressing high confinement demands beyond current literature. The results showed that transverse confinement provided by carbon FRP sheets significantly improved axial strength and deformability for all specimens, while it did not fully restore the axial stiffness achieved before fire exposure. The effectiveness of FRP confinement increased with longer fire exposure durations. Additionally, two analytical models proposed previously for predicting the axial strength and ultimate strain of FRP confined fire-damaged concrete were evaluated in terms of their accuracy. The accuracy of the predictions was reduced with an increase in exposure temperatures for both models. Therefore, a new model is proposed within the scope of study, which shows good agreement with the novel test results.Article Citation - WoS: 5Citation - Scopus: 7Targeting the Panoptosome Using Necrostatin-1 Reduces Panoptosis and Protects the Kidney Against Ischemia-Reperfusion Injury in a Rat Model of Controlled Experimental Nonheart-Beating Donor(Elsevier Science inc, 2024) Dokur, Mehmet; Uysal, Erdal; Kucukdurmaz, Faruk; Altinay, Serdar; Polat, Sait; Batcioglu, Kadir; Yeni, Sema Nur DokurPurpose. Reducing renal ischemia is crucial for the function and survival of grafts from non- heartbeat donors, as it leads to inflammatory responses and tubulointerstitial damage. The primary concern with organs from nonheartbeat donors is the long warm ischemia period and reperfusion injury following renal transplantation. This study had two main goals; one goal is to determine how Necrostatin-1 targeting the PANoptosome affects PANoptosis in the nonheartbeating donor rat model. The other goal is to fi nd out if Necrostatin-1 can protect the kidney from ischemic injury for renal transplantation surgery. Methods. Twenty-four rats were grouped randomly as control and Necrostatin-1 in this experimental animal study, and we administered 1.65 mg/kg of Necrostatin-1 intraperitoneally to the experimental group for 30 minutes before cardiac arrest. We removed the rats' left kidneys and measured various oxidative stress marker measures such as malondialdehyde, superoxide dismutase, catalase, GPx, and 8-hydroxy-2-deoxyguanosine levels. We then subjected the tissues to immunohistochemical analysis, electron microscopy, and histopathological analysis. Findings. The Necrostatin-1 group had a lower total tubular injury score (P < .001) and less Caspase-3, gasdermin D, and mixed lineage kinase domain-like protein expression. Additionally, the apoptotic index of the study group was lower (P < .001). Furthermore, the study group had higher levels of superoxide dismutase and GPx (P < .05), whereas malondialdehyde levels were reduced (P = .009). Electron microscopy also revealed a significant improvement in tissue structure in the Necrostatin-1 group. Conclusion. Necrostatin-1 protects against ischemic acute kidney injury in nonheart-beating donor rats by inhibiting PANoptosis via the blockade of RIPK1. As a result of this, Necrostatin1 may offer novel opportunities for protecting donor kidneys from renal ischemia-reperfusion injury during transplantation in patients with end-stage kidney disease requiring a renal transplantation.