Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - WoS: 1Citation - Scopus: 1Chemical Composition Optimization and Isothermal Transformation of Δ-Transformation Plasticity Steel for the Third-Generation Advanced High-Strength Steel Grade(Wiley-v C H verlag Gmbh, 2024) Okur, Onur; Davut, Kemal; Davut, Kemal; Palumbo, Gianfranco; Nalcaci, Burak; Guglielmi, Pasquale; Yalcin, Mustafa Alp; Erdogan, Mehmet; 03.09. Department of Materials Science and Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyA new low-manganese transformation-induced plasticity steel is designed with optimized nickel content to achieve superior strength and ductility while minimizing the use of expensive nickel. The steel is optimized using JMatPro software, then cast, and hot rolled. To assess the effect of intercritical annealing on austenite (martensite at room temperature) volume fraction and carbon content, hot-rolled steel samples quenched from different annealing temperatures (680-1100 degrees C) are used. Additionally, hot-rolled steel coupons are intercritically annealed at about 50% austenite formation temperature (740 degrees C) and then subjected to isothermal treatments at 300-425 degrees C for varying times (10-90 min). After optimizing these treatments to maximize retained austenite (RA), tensile specimens are heat-treated first at 740 degrees C and then isothermally at 325 degrees C. Thermodynamic calculations suggest that aluminum combined with silicon may lead to the delta ferrite formation, and even minimal nickel content can stabilize a considerable amount of austenite. In the experimental studies, it is shown that lower-temperature bainitic holding enhances austenite stability by enriching the carbon content. Optimized two-stage heat treatments yield up to 25.8% RA, with a tensile strength of 867.2 MPa and elongation of 40.6%, achieving a strength-elongation product of 35.2 GPax%, surpassing the third-generation advanced high-strength steel grades minimum requirement of 30 GPax%.Article Citation - WoS: 2Citation - Scopus: 3Development of Mg-Alginate Based Self Disassociative Bio-Ink for Magnetic Bio-Patterning of 3d Tumor Models(Wiley-v C H verlag Gmbh, 2024) Şahin, Hasan; Arslan Yıldız, Ahu; Sahin, Hasan; Arslan-Yildiz, Ahu; 04.04. Department of Photonics; 03.01. Department of Bioengineering; 03. Faculty of Engineering; 04. Faculty of Science; 01. Izmir Institute of TechnologyAlginate forms a hydrogel via physical cross-linking with divalent cations. In literature, Ca2+ is mostly utilized due to strong interactions but additional procedures are required to disassociate Ca-alginate hydrogels. On the other hand, Mg-alginate hydrogels disassociate spontaneously, which might benefit certain applications. This study introduces Mg-alginate as the main component of a bio-ink for the first time to obtain 3D tumor models by magnetic bio-patterning technique. The bio-ink contains magnetic nanoparticles (MNPs) for magnetic manipulation, Mg-alginate hydrogel as a sacrificial material, and cells. The applicability of the methodology is tested for the formation of 3D tumor models using HeLa, SaOS-2, and SH-SY5Y cells. Long-term cultures are examined by Live/dead and MTT analysis and revealed high cell viability. Subsequently, Collagen and F-actin expressions are observed successfully in 3D tumor models. Finally, the anti-cancer drug Doxorubicin (DOX) effect is investigated on 3D tumor models, and IC50 values is calculated to assess the drug response. As a result, significantly higher drug resistance is observed for bio-patterned 3D tumor models up to tenfold compared to 2D control. Overall, Mg-alginate hydrogel is successfully used to form bio-patterned 3D tumor models, and the applicability of the model is shown effectively, especially as a drug screening platform.Article Citation - WoS: 3Citation - Scopus: 3The Effect of Co-Delivery of Oxygen and Anticancer Drugs on the Viability of Healthy and Cancer Cells Under Normoxic and Hypoxic Conditions(Wiley-v C H verlag Gmbh, 2024) Kehr, Nermin Seda; Kehr, Nermin Seda; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of TechnologyHypoxia, cancer, tissue damage, and acidic pH conditions are interrelated, as chronic hypoxic conditions enhance the malignant phenotype of cancer cells, causing more aggressive tissue destruction, and hypoxic cells rely on anaerobic glycolysis, leading to the accumulation of lactic acid. Therefore, the administration of oxygen is necessary to support the functions of healthy cells until the formation of new blood vessels and to increase the oxygen supply to cancerous tissues to improve the efficacy of antitumor drugs on tumor cells. In addition to O2 supply, pH-dependent delivery of anticancer drugs is desired to target cancer cells and reduce drug side effects on healthy cells. However, the simultaneous delivery of O2 and pH-dependent anticancer drugs via nanomaterials and their effects on the viability of normal and cancer cells under hypoxic conditions have not been studied in sufficient numbers. This study describes the synthesis of a pH-responsive nanomaterial containing oxygen and anticancer drugs that exhibits sustained O2 release over a 14 d period under hypoxic conditions and pH-dependent sustained release of anticancer drugs over 30 d. The simultaneous administration of O2 and anticancer drugs results in higher cell survival of normal cells than that of cancer cells under hypoxic and normoxic conditions. The synthesis of pH-sensitive perfluorocarbon-based nanomaterials containing oxygen and anticancer drugs is reported. These nanomaterials provide oxygen release within 14 d and pH-dependent sustained release of anticancer drugs over 30 d. Co-delivery of oxygen and anticancer drugs by pH-sensitive nanomaterials promotes the viability of healthy cells compared to malignant cells under hypoxic conditions. imageArticle Citation - WoS: 10Citation - Scopus: 11Tunable Magnetism in 2d Organic-Ion Mnps<sub>3</Sub> Via Molecule-Dependent Vacancy Generation(Wiley-v C H verlag Gmbh, 2024) Tezze, Daniel; Pereira, Jose M.; Tutar, Dogukan; Ramos, Maria; Regner, Jakub; Gargiani, Pierluigi; Gobbi, Marco; 01. Izmir Institute of TechnologyThe magnetic properties of van der Waals materials are profoundly influenced by structural defects. The layered antiferromagnet MnPS3 offers a unique opportunity to explore defect-related magnetism, as Mn2+ vacancies can be generated by the intercalation of specific guest molecules. However, the effectiveness of this process in atomically thin flakes and the extent of the magnetic tunability remain unclear. Here, it is shown that the magnetic properties of MnPS3 can be tailored through the intercalation of different guest molecules. Notably, the insertion of four alkylammonium ions introduces different populations of Mn2+ vacancies, leading to a transition from the pristine antiferromagnetic state to more complex magnetic textures, including a ferrimagnetic state displaying a magnetic saturation of 1 mu B per atom. Moreover, it is shown that the intercalation of few-nm-thick flakes also leads to the emergence of a ferrimagnetic response. This in-flake intercalation, which can be monitored in real time using optical microscopy, can be interrupted before completion, generating lateral heterostructures between pristine and intercalated areas. This approach opens the way to the use of partial intercalation to define regions with distinct magnetic properties within a single flake.Article Improving the Device Stability by Controlling the Morphology of Quantum Dot Emissive Layer Via a Coating Process in Blue Qleds(Wiley-v C H verlag Gmbh, 2024) Özçelik, Serdar; Varlıklı, Canan; Diker, Halide; Ozcelik, Serdar; Varlikli, Canan; 01. Izmir Institute of Technology; 04.01. Department of Chemistry; 04.04. Department of Photonics; 04. Faculty of ScienceBlue light-emitting CdSe@ZnS/ZnS quantum dot (QD) nanoparticles (NPs) were synthesized and their photophysical properties in both solution and film phases were investigated. The morphological properties of films prepared by different coating methods i. e. single layer coating from low to high concentrations of QD solutions and layer-by-layer (multilayer) coating within constant low QD solution concentration, were also examined in detail. Varying the concentration (1-10 mg/mL) and the number of layers (from 1-16) did not essentially affect the photophysical properties of QD films, although it resulted in a direct increment in QD film thickness. The concentration and layer-dependent films were used as an emissive layer (EML) in QD light-emitting diodes (QLEDs). Although the "6 mg/ml(-1) Layer" QD EML-based device exhibited relatively high device efficiency compared to the "1 mg/ml(-10) Layers" based one at working voltage region, it had similar to 2-fold higher efficiency roll-off at high voltage region. The performance differences for both devices with the same QD EML thickness were attributed to the morphological variations for the QD layer in terms of surface roughness, void density, aggregates/clusters, and trap sites that were directly related to the charge injection balance and Auger recombination.