Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7148

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  • Article
    Cryofixation Strategy for Fabrication of Robust Gelatin-Polyester Conductive Biocomposites
    (Taylor & Francis Inc, 2026) Koksal, Busra; Onder, Ahmet; Yildiz, Umit Hakan
    The development of mechanically robust and electroconductive biomaterials is critical for advancing tissue engineering strategies, particularly in neural, cardiac and musculoskeletal applications. Here, we report a polycaprolactone (PCL)-gelatin conductive polymer (poly(3,4-ethylenedioxythiophene):polystyrene sulfonate, PEDOT:PSS) biocomposite with tunable mechanical and electrical properties, fabricated via the cryofixation process relying on rapid reaction between isocyanate-terminated PCL, gelatin and PEDOT:PSS. Two isocyanate sources, hexamethylene diisocyanate (HDI) or isophorone diisocyanate (IPDI) were employed to obtain reactive end-functionalized PCLHDI and PCLIPDI. The cryofixation (at -18 degrees C) of PCLHDI or PCLIPDI, gelatin and PEDOT:PSS was found to occur in unfrozen microdomains and enabled the resultant gel with an inherited network of ice, thereby increasing porosity. Electroconductivity was introduced via the incorporation of PEDOT:PSS, yielding conductive cryogels with porous morphology. The resulting scaffolds exhibited a Young's modulus of 637 Pa and electrical conductivity of 197 mu S/cm, alongside biocompatible nature of gelatin-based gels. This multifunctional platform offers significant promise for the engineering of electrically active tissues.
  • Article
    FW-S3PFCM: Feature-Weighted Safe-Semi Possibilistic Fuzzy C-Means Clustering
    (Springer, 2026) Khezri, Shirin; Aghazadeh, Nasser; Hashemzadeh, Mahdi; Golzari Oskouei, Amin
    The safe semi-supervised fuzzy c-means clustering (S3FCM) method is a well-known clustering method that can produce successful results by incorporating prior knowledge of the class distribution. Its process is fast and simple but still has two limitations. The first issue is that it gives equal weight to all data features, while in real-world applications, different features usually have different importance. Secondly, S3FCM is very sensitive to noise and outliers. This paper proposes an extension of the S3FCM, entitled FW-S3PFCM, to mitigate these shortcomings. The proposed method uses a local feature weighting scheme to consider the different feature weights in the clustering process. Additionally, a possibilistic version of the S3FCM is designed to reduce the sensitivity to noise and outliers. The effectiveness of the proposed method is comprehensively evaluated on various benchmark datasets, and its performance is compared with the state-of-the-arts methods. To practically asses the FW-S3FCM, a real-world dataset of brain MRI images and its segmentation performance are analyzed as well. The average Accuracy, F1-score, Sensitivity, and Precision measures obtained by FW-S3FCM are 0.9682, 0.9826, 0.9743, and 0.9925, respectively, which are better than the competitors' performance.
  • Article
    Alterations in Secondary Lipids Are Associated with Neuroinflammation in the Brain of Neu1-Deficient Mice
    (Springer, 2026) Ada, Ebru; Seyrantepe, Volkan
    Neu1 (lysosomal sialidase 1) is essential for removing sialic acid from oligosaccharides and glycoconjugates. Neu1 deficiency impairs lysosomal digestion, leading to sialidosis and sialoglycoprotein accumulation. It also increases lipids, including gangliosides GM3, GD3, GM4, and LM1, in the kidney, liver, and spleen. Neu1-/- mice display symptoms resembling Type II sialidosis, including enlarged spleen and liver, kidney issues, neurological problems, spinal defects, and oligosaccharide buildup. The study examined secondary lipid alterations and inflammation in the cortex and cerebellum of these mice. Lipidomic, molecular, and immunohistochemical analyses of tissues from 2 and 5 M Neu1-/- mice revealed reduced levels of lipids, including PC, PE, PS, and CL, along with increased pro-inflammatory cytokines and loss of oligodendrocytes and neurons. Signs of astrogliosis and microgliosis emerged in specific brain regions. These results indicate that reduced levels of glycerophospholipids could serve as an indicator of inflammation in sialidosis mice. Future research should investigate therapies targeting these lipid changes, as modulating glycerophospholipids might slow disease progression in sialidosis patients.
  • Article
    Gamma Secretase Inhibitors, DAPT and MK0752, Exhibit Synergistic Anticancer Effects with Cisplatin and Docetaxel in 2D and 3D Models of Breast Cancer
    (TÜBİTAK Scientific & Technological Research Council of Turkey, 2025) Telli, Kubra; Gubat, Johannes; D'Arcy, Padraig; Ozuysal, Ozden Yalcin
    Background/aim: Breast cancer remains a major malignancy among women, and severe side effects and the development of acquired drug resistance frequently hinder current therapeutic strategies. The Notch signaling pathway, a key regulator of cell fate, is commonly dysregulated in breast cancer and associated with poor prognosis. Gamma-secretase inhibitors (GSIs) block Notch receptor activation and have shown potential anticancer efficacy. This study aimed to investigate the synergistic activity of two commonly used GSIs, DAPT and MK0752, combined with docetaxel or cisplatin in both 2D and 3D breast cancer models. Materials and methods: Triple-negative, highly metastatic MDA-MB-231 and ER+/PR+ MCF-7 breast cancer cell lines were treated with DAPT or MK0752 alone or in combination with docetaxel or cisplatin. Drug efficacy and potential synergism were evaluated in 2D monolayer cultures and 3D spheroid models. Sequential treatment strategies were also assessed, where docetaxel or cisplatin was administered prior to GSI exposure. Results: Both MDA-MB-231 and MCF-7 cell lines exhibited notable sensitivity to DAPT and MK0752 combinations with docetaxel or cisplatin in 2D and 3D cultures. Synergistic enhancement of cytotoxicity was observed, particularly in sequential treatment regimens. Pretreatment with docetaxel or cisplatin followed by GSI exposure demonstrated superior growth inhibition compared with either monotherapy or simultaneous combination treatments. Conclusion: This study highlights the therapeutic potential of combining GSIs with standard chemotherapeutics to overcome drug resistance in breast cancer. The observed synergy and sequencing effects provide a strong basis for further mechanistic and translational investigations to optimize GSI-based combinational therapy strategies.
  • Article
    Triple Helix Spaces: A Tale of Three Helices
    (Routledge Journals, Taylor & Francis Ltd, 2025) Kose, Suheda; Elburz, Zeynep; Velibeyoglu, Koray; Oner, Asli Ceylan
    In recent years, the Triple Helix model has gained prominence within academic circles. This study, situated in the field of city planning, aims to clarify the model's theoretical foundations, evaluate its measurement techniques, and explore the relationship between the Triple Helix and urban space. By examining 231 Triple Helix-related publications from the past 40 years (up to 12 July 2024, sourced from the Web of Science Core Collection), we propose a framework of three distinct generations for understanding Triple Helix spaces in urban contexts. The first-generation Triple Helix space is characterized by direct interactions among the three primary actors: university, industry, and government. The second-generation expands on this by including multiple interactions among the three main actors and their facilitators. The third-generation involves the circular interaction of multiple second-generation Triple Helix spaces. Across these generations, the study provides a lens for analyzing innovative urban spaces through Triple Helix interactions and offers practical approaches for examining the Triple Helix spaces. The findings also contribute to the theoretical foundation for the sustainable development of such spaces.
  • Article
    Mass Spectrometric Profiling Reveals Alterations in N-Glycans and O-Glycans in Tay-Sachs Disease Under Autophagy-Induced Conditions
    (Springer, 2025) Can, Melike; Basirli, Hande; Jin, Chunsheng; Karlsson, Niclas G.; Bojar, Daniel; Seyrantepe, Volkan
    Tay-Sachs disease is a rare neurodegenerative disorder caused by mutations in the HEXA gene. The HEXA gene encodes the alpha-subunit of the enzyme beta-hexosaminidase A, which degrades GM2 ganglioside. Previously, we identified impaired autophagy in the brains of a mouse model of Tay-Sachs disease, which exhibited neuropathological and clinical abnormalities. Moreover, we demonstrated autophagosome clearance in Tay-Sachs cells under lithium-induced conditions. Here, we further aimed to evaluate N- and O-glycan changes in these cells and examine whether glycan alterations are linked to ER stress. The profiles of N- and O-glycans were analyzed using LC-MS/MS in fibroblasts and neuroglial cells from 5-month-old Hexa-/-Neu3-/- mice and neuroglial cells from Tay-Sachs patients under lithium induction and nutrient deprivation. The expression levels of ER stress-related markers were assessed using qRT-PCR and Western blot analyses. We demonstrated higher levels of high mannose and lower levels of complex types of N-glycans, along with increased O-glycan levels in Tay-Sachs cells. Compared to control groups, we observed upregulated expression of endoplasmic reticulum (ER) stress-related markers, CHOP and ATF-6, in Tay-Sachs cells. Our study demonstrated that autophagy induction causes the degradation of accumulated high-mannose N-glycans and O-glycans, which is associated with the downregulation of ER stress-related genes in Tay-Sachs cells. Our study is the first to show this phenomenon in Tay-Sachs cells and suggests the presence of ER stress-mediated autophagy. Therefore, targeting glycans through autophagy induction could offer therapeutic benefits to patients with Tay-Sachs disease in future studies.
  • Article
    Effects of Grain Refinement, Eutectic Modification, and T6 Heat Treatment on Tribological Properties of Al8Si3Cu Alloys
    (Springer India, 2026) Gurtaran, Mikdat; Uludag, Muhammet
    In this study, the effects of grain refinement and eutectic modification on the wear behaviour of Al8Si3Cu cast alloys produced both before and after degassing were investigated in detail. Grain refinement and eutectic modification were conducted by adding AlTi5B1, Al3B, and AlSr15, respectively. Following the casting process, half of the samples were T6 heat-treated to evaluate the impact of heat treatment on their wear rate. Adhesive wear testing was conducted using a steel ball under a load of 3 N, at a speed of 8 mm/s over 20 m in dry and oily mediums. Microstructural characterisation was performed using optical microscopy and scanning electron microscopy. The results revealed that grain refinement enhances wear resistance by reducing the secondary dendrite arm spacing and strengthening the aluminium matrix. Conversely, while T6 heat treatment significantly promotes the precipitation of secondary phases and intermetallic compounds, improving wear resistance, it also results in more superficial wear on T6-treated samples, which can be attributed to insufficient surface wettability during the solution treatment stage of T6 heat treatment.
  • Article
    Dimensionality Effects in Anisotropic Single Layers TiSe5 and TiTe5: a Comparative Study of 2D Sheets and 1D Nanochains
    (IOP Publishing Ltd, 2026) Can Dogan, Kadir; Kutay Tamdogan, Omer; Bozkurt, Yagmur; Cetin, Zebih; Yagmurcukardes, Mehmet
    In this study, we present a comprehensive first-principles investigation of the structural, vibrational, and electronic properties of titanium pentachalcogenide structures in both two-dimensional (2D) and one-dimensional (1D) nanochain (NC) forms. Total energy and geometry optimizations reveal that the 2D TiX5 (X = Se, Te) structures exhibit in-plane anisotropy arising from the trigonal prismatic TiX3 units interconnected via the chalcogenide chains. Phonon band dispersions and elastic tensor elements confirm the dynamical and mechanical stability of the 2D layers, respectively. Electronically, while TiTe5 is a metal, TiSe5 possesses direct band gap semiconducting behavior. In addition, free-standing 1D NC counterparts, which are sub-units of the 2D structures, are investigated by means of their stability. Three stable 1D NCs, namely TiTe5-NC, TiSe7-NC, and TiTe7-NC, are found to be composed of edge-sharing TiX6-like units with either five- or seven-fold coordination. The dynamically stable 1D NCs are shown to be semiconductors with relatively larger band gaps as compared to 2D layers. Predicted Raman spectra reveal clear signatures of vibrational mode evaluations as a result of quantum confinement from the 2D layer to the 1D NC. Moreover, finite-temperature ab-initio quantum molecular dynamics simulations at 300 K confirm the thermal stability of both the 2D TiX5 layers and 1D NC derivatives, showing that the Ti-based systems retain their structural integrity under ambient conditions and are feasible candidates for experimental synthesis. Our findings highlight the formation of stable semiconducting 1D NCs of Ti-pentachalcogenides from their 2D counterparts.
  • Article
    Importance of Zoning for Vertical Circulation Planning of Densely Populated Buildings: A Simulation Based Approach for Elevator Traffic Analyses
    (Gazi Univ, 2025) Deligoz, Dostcan; Harputlugil, Timucin
    Elevator systems are essential in multi-story buildings, affecting circulation, travel time, and user comfort. Traditional design methods, based on mathematical calculations, provide initial estimates of elevator numbers and capacities by considering basic operational criteria. However, these methods cannot fully capture dynamic passenger flows and temporal variations in demand. Dynamic simulation-based elevator traffic analysis, on the other hand, allows for more comprehensive evaluation of elevator operations and enables testing of alternative zoning scenarios. In this study, a dynamic simulation-based analysis is applied as a case study for a hospital outpatient building. Different zoning strategies are implemented for elevator groups to evaluate their effect on system performance. Performance criteria, including Average Waiting Time (AWT), Average Time To Destination (ATTD), and Interval (INT), are assessed across different zoning scenarios and compared with values commonly reported in the literature. The results highlight the potential of zoning to improve elevator performance, including passenger handling, waiting times, and travel efficiency. Especially in buildings where physical modifications are difficult, the combination of simulation-based analysis and carefully designed zoning strategies can reveal the potential for enhancing operational performance and optimizing elevator efficiency within existing physical constraints.
  • Article
    Interventions in Historic Urban Sites After Earthquake Disasters
    (MDPI, 2025) Demir, Hatice Aysegul; Turan, Mine Hamamcioglu
    Earthquakes, fires, and climate change-related hazards increasingly threaten cultural heritage. Documenting and identifying the significance of heritage sites before disasters is essential for archival purposes and for guiding post-disaster interventions such as consolidation, reconstruction, or redesign. Although various post-disaster strategies exist in the literature, they often lack consideration of pre-disaster values and authentic qualities, limiting their effectiveness in value-based regeneration. This study proposes a framework for managing post-disaster interventions grounded in pre-disaster documentation of heritage values, authenticity, and integrity. The methodology includes seven phases: case selection; site survey and documentation; thematic analysis and mapping; quantification of qualitative data; synthesis of pre-disaster analysis results to define values, problems, and potentials; post-disaster assessment using aerial and terrestrial imagery; and development of targeted intervention strategies. This study focuses on two areas in Antakya, T & uuml;rkiye: Kurtulu & scedil; Street and Kuyulu Neighborhood, affected by the 2023 earthquake (M 7.7). These areas represent different historical layers: a Hellenistic grid plan with French-style buildings, and an organic Ottoman settlement morphology, respectively. Conservation data collected in 2019 inform the analysis. Mapping techniques evaluate attributes such as spatial characteristics, typologies, and structural systems. The study concludes that traces of pre-disaster spatial patterns and building features should inform post-disaster designs, ensuring sustainable, earthquake-resistant, and value-based interventions.