TR Dizin İndeksli Yayınlar / TR Dizin Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7149
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Article The Association of Vertebrobasilar System Morphology and Geometry With the Posterior and Anterior Ischemic Stroke(Pera Yayıncılık Hizmetleri, 2025) Leblebici, Asım; Demirtas, İsmet; Ayyıldız, Sevilay; Ayyıldız, Behçet; Kuş, Koral Çağlar; Ayran, Ayşegül; Kurt, Mustafa AyberkObjective: Morphometric and geometric variations in the vertebrobasilar system (VBS) may influence cerebral hemodynamics, potentially contributing to ischemic strokes in both anterior and posterior circulatory territories. This study aimed to investigate the association between VBS morphology and ischemic stroke localization. Methods: This retrospective observational study analyzed multidetector computed tomography angiography images from 431 patients (187 females, 244 males, mean age: 65.3 ± 14.6 years). Patients were categorized into three groups: anterior circulation ischemic stroke (ACIS, n=184), posterior circulation ischemic stroke (PCIS, n=88), and control subjects (n=159). Morphometric parameters were assessed using 3D Slicer software. Results: Significant differences in basilar artery (BA) length were observed between stroke groups and controls, with ACIS and PCIS groups exhibiting longer BA lengths (p<0.05). Males had significantly longer vertebral artery (VA) lengths than females in the control and ACIS groups (p value < 0.05). The vertebrobasilar junction angle was significantly wider in females than in males (p value = 0.046). BA bending was predominantly directed to the right across all groups, with no significant differences between the stroke and control groups. VA dominance was more frequent on the left in ACIS and the right in PCIS, while VA hypoplasia was less common in stroke patients compared to controls, contrary to previous reports. Conclusion: While certain morphometric and geometric variations in the VBS were observed, the evidence for a direct association between these characteristics and the localization of ischemic stroke was limited and inconclusive. These findings suggest that vertebrobasilar morphology may not independently determine stroke localization.Article Citation - WoS: 2Citation - Scopus: 1Çelik Fiber Katkısının Farklı Boyuna Donatı Oranına Sahip Betonarme Döşemelerin Zımbalama Davranışı Üzerinde Etkileri(2019) Saatci, Selcuk; Yasayanlar, Suleyman; Yasayanlar, Yonca; Batarlar, BaturaySunulan çalışmada her iki yönde birbirine dik 0,004 (D1 serisi) ve 0,002 (D2 serisi) oranında boyuna donatıiçeren 2150x2150x150 mm boyutlarında iki grup betonarme döşeme, hacimce %0, %0,5, %1 ve %1,5oranında çelik fiber katkısı içeren beton karışımlarıyla dökülmüştür. Üretilen toplam sekiz döşeme ortanoktalarından statik yük altında test edilmişlerdir. Çelik fiber katkısı olmayan numunelerde yüksek boyunadonatı oranına sahip döşeme boyuna donatısında akma gerçekleşmeden gevrek bir şekilde zımbalamagöçmesi oluşurken düşük boyuna donatı oranına sahip döşeme zımbalama gerçekleşmeden önce çok dahasünek bir davranış göstermiştir. Çelik fiber katkısı her iki boyuna donatı oranında da iki kata varan oranlardazımbalama dayanımı artışlarına sebep olmuştur. Ancak D1 serisi döşemelerde çelik fiber katkısı maksimumyer değiştirmeleri önemli ölçüde arttırırken D2 serisinde maksimum yer değiştirmelerde önemli bir farkoluşmamış, bu döşemelerin yer değiştirmesi boyuna donatının akması tarafından kontrol edilmiştir. Çelikfiber katkısı oranının arttırılması D1 serisi döşemelerde dayanımın ve maksimum yer değiştirmelerinartmasına sebep olurken, D2 serisi döşemelerde %1'in üstü çelik fiber katkı oranları davranışta önemli birfark oluşturmamıştır. Yapılan deneyler Kritik Kesme Çatlağı Teorisi kullanılarak analitik olarakmodellenmiş ve bu tip modelleme ile ilgili bazı iyileştirmeler önerilmiştir.Article İzmir’in Toplu Ulaşım Sisteminin Doğrusal Programlama ve Duyarlılık Analizi Aracılığıyla Optimizasyonu(Pamukkale Univ, 2024) Görgülü, Çağla; Görgülü, Lale; Duvarcı, YavuzBu çalışma, enerji tüketimi, seyahat süresi ve ulaşım ücreti perspektiflerinden toplu ulaşım problemlerine odaklanmaktadır. Çalışmanın amacı İzmir örneğinde görülen benzer ulaşım sorunlarına yönelik güzergâh açısından karşılaştırılabilir olan tramvay ve otobüs sistemleri için en iyi çözümleri sunmaktır. Ayrıca, bu çalışma farklı ulaşım tipleri arasındaki bütünleşme konusuna dikkat çekmektedir. Çalışmada kullanılan yöntemler doğrusal programlama ve duyarlılık analizidir. Bu çalışma için hem tramvay hem de otobüs hattına sahip dokuz rota belirlenmiştir. Hangi ulaşım tipinin daha uygun veya kullanışlı olduğunu, bunların olumsuz ve olumlu sonuçlarının neler olduğunu ve hangisinin çevre dostu ve yolcu bütçesine dost olduğunu incelemek üzere aynı aktarma noktalarını paylaşan rotalar seçilmiştir. Doğrusal programlama Microsoft Excel® yazılımının bir uzantısı olan çözücü aracıyla gerçekleştirilmiştir. İlk olarak, amaç fonksiyonları en küçük enerji tüketimi, en küçük rota uzunluğu ve en küçük yolcu ücreti olarak tanımlanmıştır. Elde edilen enerji tüketimi, hız ve yolcu hacmi verileri optimizasyonların kısıtlarıdır. Son olarak, bulgular duyarlılık analizi aracılığıyla değerlendirilmiştir. Hem yolcular hem ulaşım işletmecileri için otobüs ve tramvay seçenekli en iyi sonuçlar tespit edilmiştir. En uygun rotalar Fahrettin Altay-Alsancak, Fahrettin Altay-Halkapınar, Mavişehir-Bostanlı ve Egekent-Bostanlı rotalarıdır. Bu çalışma, ulaşım maliyet matrisinin yanı sıra seyahat süresi matrisini kullanarak literatüre katkı sağlamaktadır. Böylece, bu araştırma sadece mali amaçlara değil, çevresel ve sosyal amaçlara da hizmet etmektedir.Article Cytoplasmically Localized Trna-Derived Fragments Inhibit Translation\rin Drosophila S2 Cells(2022) Hamıd, Syed Muhammad; Akgül, BünyaminTransfer ribonucleic acids (tRNAs) serve not only as amino acid carriers during translation but also as a template for the biogenesis of short fragments that can regulate gene expression. Despite recent progress in the function of tRNA-derived fragments (tRFs), their intracellular localization, protein partners, and role in regulating translation are not well understood. We used synthetic tRFs to investigate their localization and function in Drosophila S2 cells. Under our experimental setting, all synthetic tRFs tested were localized at distinct sites within the cytoplasm in a similar manner in Drosophila S2 cells. Cytoplasmically-localized tRFs were positioned in close proximity to GW182 and XRN1 proteins. Functionally, tRFs, which slightly suppressed proliferation in S2 cells, inhibited translation without any major shift in the polysome profile. These results suggest that 5’-tRFs are cytoplasmically-localized and regulate gene expression through inhibition of translation in Drosophila.Article Performance Analysis and Feature Selection for Network-Based Intrusion Detection\rwith Deep Learning(2022) Caner, Serhat; Erdoğmuş, Nesli; Erten, Y. MuratAn intrusion detection system is an automated monitoring tool that analyzes network traffic and detects\rmalicious activities by looking out either for known patterns of attacks or for an anomaly. In this study, intrusion\rdetection and classification performances of different deep learning based systems are examined. For this purpose, 24\rdeep neural networks with four different architectures are trained and evaluated on CICIDS2017 dataset. Furthermore,\rthe best performing model is utilized to inspect raw network traffic features and rank them with respect to their\rcontributions to success rates. By selecting features with respect to their ranks, sets of varying size from 3 to 77 are\rassessed in terms of classification accuracy and time efficiency. The results show that recurrent neural networks with a\rcertain level of complexity can achieve comparable success rates with state-of-the-art systems using a small feature set\rof size 9; while the average time required to classify a test sample is halved compared to the complete set.Article Citation - WoS: 1Citation - Scopus: 2Lacoo3 Is a Promising Catalyst for the Dry Reforming of Benzene Used as a Surrogate of Biomass Tar(Tubitak Scientific & Technological Research Council Turkey, 2024) Çağlar, Başar; Üner, DenizTar build-up is one of the bottlenecks of biomass gasification processes. Dry reforming of tar is an alternative solution if the oxygen chemical potential on the catalyst surface is at a sufficient level. For this purpose, an oxygen-donor perovskite, $LaCoO_3$, was used as a catalyst for the dry reforming of tar. To circumvent the complexity of the tar and its constituents, the benzene molecule was chosen as a model compound. Dry reforming of benzene vapor on the $LaCoO_3$ catalyst was investigated at temperatures of 600, 700, and 800 °C; at $CO_2/C_6H_6$ ratios of 3, 6, and 12; and at space velocities of 14,000 and 28,000 h–1. The conventional Ni(15 wt.%)/$Al_2O_3$ catalyst was also used as a reference material to determine the relative activity of the $LaCoO_3$ catalyst. Different characterization techniques such as X-ray diffraction, $N_2$ adsorption-desorption, temperature-programmed reduction, and oxidation were used to determine the physicochemical characteristics of the catalysts. The findings demonstrated that the $LaCoO_3$ catalyst has higher $CO_2$ conversion, higher $H_2$ and CO yields, and better stability than the Ni(15 wt.%)/γ-$Al_2O_3$ catalyst. The improvement in activity was attributed to the strong capacity of $LaCoO_3$ for oxygen exchange. The transfer of lattice oxygen from the surface of the $LaCoO_3$ catalyst facilitates the oxidation of carbon and other surface species and leads to higher conversion and yields.Article Citation - WoS: 3Citation - Scopus: 3Β-Ketoenamine-linked covalent organic framework for efficient iodine capture(Tubitak Scientific & Technological Research Council Turkey, 2024) Büyükçakır, OnurExploring the materials that effectively capture radioactive iodine is crucial in managing nuclear waste produced from nuclear power plants. In this study, a β-ketoenamine-linked covalent organic framework (bCOF) is reported as an effective adsorbent to capture iodine from both vapor and solution. The bCOF’s high porosity and heteroatom-rich skeleton offer notable iodine vapor uptake capacity of up to 2.51g $g^{–1}$ at 75 °C under ambient pressure. Furthermore, after five consecutive adsorption-desorption cycles, the bCOF demonstrates high reusability performance with significant iodine vapor capacity retention. The adsorption mechanism was also investigated using various ex situ structural characterization techniques, and these mechanistic studies revealed the existence of a strong chemical interaction between the bCOF and iodine. The bCOF also showed good iodine uptake performance of up to 512 mg $g^{–1}$ in cyclohexane with high removal efficiencies. The bCOF’s performance in adsorbing iodine from both vapor and solution makes it a promising material to be used as an effective adsorbent in capturing radioactive iodine emissions from nuclear power plants.Article Citation - WoS: 2Citation - Scopus: 2Enrichment of Turkish Question Answering Systems Using Knowledge Graphs(Tubitak Scientific & Technological Research Council Turkey, 2024) Ciftci, Okan; Soygazi, Fatih; Tekir, SelmaRecent capabilities of large language models (LLMs) have transformed many tasks in Natural Language Processing (NLP), including question answering. The state-of-the-art systems do an excellent job of responding in a relevant, persuasive way but cannot guarantee factuality. Knowledge graphs, representing facts as triplets, can be valuable for avoiding errors and inconsistencies with real-world facts. This work introduces a knowledge graph-based approach to Turkish question answering. The proposed approach aims to develop a methodology capable of drawing inferences from a knowledge graph to answer complex multihop questions. We construct the Beyazperde Movie Knowledge Graph (BPMovieKG) and the Turkish Movie Question Answering dataset (TRMQA) to answer questions in the movie domain. We evaluate our proposed question answering pipeline against a baseline study. Furthermore, we compare it with a question answering system built upon GPT-3.5 Turbo to answer the 1-hop questions from TRMQA. The experimental results confirm that link prediction on a knowledge graph is quite effective in answering questions that require reasoning paths. Finally, we provide insights into the pros and cons of the provided solution through a qualitative study.Article Citation - WoS: 1Citation - Scopus: 2Integration of Daylight Use and Analysis in Double Skin Facades: a Literature Review(Gazi Universitesi, 2024) Kazanasmaz, Tugce; Ünlütürk, Mustafa SerhanDouble skin facades (DSF) aim to save energy reducing the heat losses in buildings. They are visually appeal while allowing to use daylight efficiently. Such facade systems can reduce glare and distribute daylight evenly in the interior when compared to conventional facade systems. That is a result of cavities between two glass facades and locating sun shading elements in them, although this system provides a high level of transparency. As their primary purpose of application is to ensure thermal performance and ventilation, most studies in literature have focused on these. This study started with the hypothesis that studies examining daylight performance in DSFs are more limited than studies examining thermal performance and that daylight optimization methods are not used sufficiently in DSFs. In this context, the study aims to analyze studies focusing on daylight performance of DSFs. The review targets results of such current studies to guide future ones providing feedback knowledge. This may help to better technical developments in such facades and make them prevail in constructions or in retrofitting So, it contributes to literature in this sense. Recent studies are shown in tabulated form and interpreted in detail with graphics. considering their methodologies, daylight parameters and findings. Results show that the daylight parameter is one of the most important issues that architects or designers should consider from the moment they start the design, and they should make their designs based on the optimum penetration of daylight into the building. Consequently, this review presents that the use of daylight optimization has started to be used in recent studies dealing with DSFs. A DSF design can optimally get daylight into the interior can be made by using this method more frequently.Article Citation - WoS: 4Citation - Scopus: 3Expression Patterns of M6a Rna Methylation Regulators Under Apoptotic Conditions in Various Human Cancer Cell Lines(TUBITAK, 2024) Alasar, Azime Akçaöz; Sağlam, Buket; Vatansever, İpek Erdoğan; Akgül, BünyaminBackground/aim: Cancer is a complex disease that involves both genetic and epigenetic factors. While emerging evidence clearly suggests that changes in epitranscriptomics play a crucial role in cancer pathogenesis, a comprehensive understanding of the writers, erasers, and readers of epitranscriptomic processes, particularly under apoptotic conditions remains lacking. The aim of this study was to uncover the changes in the expression of m6A RNA modifiers under apoptotic conditions across various cancer cell lines. Materials and methods: Initially, we quantified the abundance of m6A RNA modifiers in cervical (HeLa and ME180), breast (MCF7 and MDA-MB-231), lung (A549 and H1299), and colon (Caco-2 and HCT116) cancer cell lines using qPCR. Subsequently, we induced apoptosis using cisplatin and tumor necrosis factor-alpha (TNF-α) to activate intrinsic and extrinsic pathways, respectively, and assessed apoptosis rates via flow cytometry. Further, we examined the transcript abundance of m6A RNA modifiers under apoptotic conditions in cervical, breast, and lung cancer cell lines using qPCR. Results: Overall, treatment with cisplatin increased the abundance of m 6A modifiers, whereas TNF-α treatment decreased their expression in cervical, breast, and lung cancer cell lines. Specifically, cisplatin-induced apoptosis, but not TNF-α-mediated apoptosis, resulted in decreased abundance of METTL14 and FTO transcripts. Additionally, cisplatin treatment drastically reduced the abundance of IGF2BP2 and IGF2BP3 readers. Conclusion: These results suggest that the differential response of cancer cells to apoptotic inducers may be partially attributed to the expression of m6A RNA modifiers.