Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
Browse
11 results
Search Results
Article Influence of Soil Characteristics on the Phytochemistry of Evergreen Ivy (Hedera Helix L.) Leaves in Deciduous Forests(Wiley-v C H verlag Gmbh, 2025) Yildirim, Elif Begum; Özdemir, Durmuş; Ozer, Gulcin; Sen, Nisa Beril; Ozdemir, Emrah; Makineci, Ender; Ozdemir, Durmus; Guzelmeric, Etil; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of TechnologyThe evergreen ivy (Hedera helix L.), traditionally used to treat respiratory conditions, contains triterpene saponins, primarily hederacoside C, and various phenolic compounds. This study investigated the relationships between the chemical composition of ivy leaves and their natural growing conditions (moisture, temperature, pH, and electrical conductivity of soil). Ivy leaves were collected monthly over 1 year from oak and beech forests. Hederacoside C, rutin, chlorogenic acid (ChA), neoChA, 4,5-dicaffeoylquinic acid (DCQA), and 3,5-DCQA were analyzed by high-performance thin-layer chromatography (HPTLC) and high-performance liquid chromatography (HPLC). Soil parameter data, along with the quantitative HPLC results of ivy leaves, were first subjected to bivariate analysis, which revealed significant correlations, particularly between soil moisture, soil temperature, and the chemical composition of ivy leaves. In addition, ivy samples were classified and clustered based on seasons by principal component analysis (PCA) and hierarchical cluster analysis (HCA), regardless of their collection sites. Digitized HPTLC chromatograms were evaluated by PCA and partial least squares discriminant analysis (PLS-DA) analyses; PCA enabled the grouping of ivy leaves based on their collection sites, and PLS-DA categorized the samples by seasons. The evaluation of the relationships between the phytochemistry of ivy leaves and their natural growing conditions has been reported for the first time.Article The Effect of Co-Delivery of Oxygen and Antibacterial Drug Gentamicin From Alginate-Based Nanocomposite Hydrogels on Bacterial Apoptosis and Cell Viability(Wiley-v C H verlag Gmbh, 2025) Tepeli, Dilek; Kehr, Nermin Seda; Tepeli, Dilek; Demirci, Eylem Kurulgan; Pehlivanoglu, Pelin; Kehr, Nermin Seda; 04.01. Department of Chemistry; 01. Izmir Institute of Technology; 04. Faculty of ScienceThere is a need to develop multifunctional biomaterials that can deliver oxygen and antibacterial drugs together for effective wound healing applications. Here, we report a novel biomaterial capable of co-delivering O2 and the antibacterial drug Gentamicin (GEN) for a period of 7 and 15 days, respectively. This biomaterial is fabricated by the synthesis of perfluorocarbon-based periodic mesoporous organosilica (PMOF) and the loading of its pores with GEN (GENPMOF). The synthesized GENPMOF is incorporated in alginate hydrogel to obtain Alg-GENPMOF with O2 and GEN co-delivery ability. Our results show that PMOF and GENPMOF have concentration-dependent toxicity on both Gram-negative E. coli and Gram-positive S. aureus bacteria. The most effective concentration of PMOF and GENPMOF (0.5 mg/mL) show little toxic effect for fibroblast cells. On the other hand, Alg-PMOF and Alg-GENPMOF prepared using this concentration require a long incubation time with E. coli to induce apoptosis. However, an incubation period of 1 day is sufficient to inhibit the growth of S. Aureus. Furthermore, Alg-PMOF and Alg-GENPMOF increase fibroblast cell viability under both normoxic and hypoxic conditions while slightly decreasing cancerous Malme-3M cell viability within 5 days of incubation.Article Citation - WoS: 2Citation - Scopus: 3Magnetic Levitational Assembly of Differentiated Sh-Sy5y Cells for Aβ-Induced 3d Alzheimer's Disease Modeling and Curcumin Screening(Wiley-v C H verlag Gmbh, 2025) Bilginer-Kartal, Rumeysa; Arslan Yıldız, Ahu; Arslan-Yildiz, Ahu; 03.01. Department of Bioengineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyAlzheimer's disease is one of the prevalent neurodegenerative diseases and is characterized by amyloid beta aggregate (A beta) accumulation. This study reports an A beta 1-42 induced 3D Alzheimer's disease modeling utilizing differentiated SH-SY5Y spheroids, which is carried out by Magnetic levitation approach, and the neuroprotective effect of Curcumin is further investigated on this model. For this purpose, SH-SY5Y spheroids are differentiated using Retinoic acid-Brain-derived neurotrophic factor sequentially during 3D cell culture. Differentiated spheroids maintained high viability and exhibited significant neuronal characteristics, as evidenced by increasing beta-III tubulin and NeuN expressions. 3D Alzheimer's disease model formation and neurotoxicity of A beta 1-42 aggregates are investigated on un-/differentiated spheroids, resulting in 65% and 51% cell viability, respectively. Characterization of the 3D Alzheimer's disease model is done by immunostaining of Choline acetyltransferase to investigate cholinergic neuron activity loss, showing a 2.2 decrease in fluorescence intensity. Further, Curcumin treatment on the 3D Alzheimer's disease model resulted in augmenting cell viability, confirming neuroprotective effect of Curcumin on A beta 1-42 induced Alzheimer's disease model. This study highlighted the magnetic levitation-based fabrication of A beta 1-42-induced 3D Alzheimer's disease model successfully, offering a promising experimental platform for other neurodegenerative disease research and potential clinical applications.Article Citation - WoS: 14Citation - Scopus: 14Quantum Optics Applications of Hexagonal Boron Nitride Defects(Wiley-v C H verlag Gmbh, 2025) Ateş, Serkan; Cholsuk, Chanaprom; Gale, Angus; Kianinia, Mehran; Pacal, Serkan; Ates, Serkan; Vogl, Tobias; 04.05. Department of Pyhsics; 04. Faculty of Science; 01. Izmir Institute of TechnologyHexagonal boron nitride (hBN) has emerged as a compelling platform for both classical and quantum technologies. In particular, the past decade has witnessed a surge of novel ideas and developments, which may be overwhelming for newcomers to the field. This review provides an overview of the fundamental concepts and key applications of hBN, including quantum sensing, quantum key distribution, quantum computing, and quantum memory. Additionally, critical experimental and theoretical advances that have expanded the capabilities of hBN are highlighted, in a cohesive and accessible manner. The objective is to equip readers with a comprehensive understanding of the diverse applications of hBN, and provide insights into ongoing research efforts.Article Citation - WoS: 2Citation - Scopus: 2Hybrid Preceramic Aerogels for Oil and Solvent Cleanup(Wiley-v C H verlag Gmbh, 2025) Icin, Oyku; Ahmetoğlu, Çekdar Vakıf; Vakifahmetoglu, Cekdar; 03.09. Department of Materials Science and Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyThis study presents the first synthesis and characterization of monolithic hybrid preceramic aerogels using distinct drying techniques: ambient pressure (ambigels) and CO2 supercritical drying. Polymeric ambi/aerogels, derived from polyhydromethlysiloxane (PHMS) and divinylbenzene (DVB), are processed at 200 degrees C, while hybrid ceramic-polymer (ceramer) is produced through pyrolysis at 600 degrees C. Despite variations in drying methods, polymer and ceramer ambi/aerogels exhibit comparable microstructural characteristics, bulk density, pore size and volume, and specific surface area (542-841 m(2) g(-1)). Polymeric and ceramer ambigel with 90 vol% total porosity yield a compressive strength, reaching 2.5 MPa, demonstrating a low thermal conductivity of 0.046 W m-1 K-1. Sorption tests are conducted using oil and organic solvents in aqueous media to benefit their high hydrophobicity (112 degrees < theta < 142 degrees). Aerogels exhibit high sorption capacities: 13.17 g g(-1) for sesame oil, 11.74 g g(-1) for toluene, and 9.19 g g(-1) for n-hexane. The sorption rate for the oil is nearly 10 times slower than that for toluene and n-hexane. Regarding regeneration and reusability, polymer and ceramer aerogels show consistent sorption properties cycles tested for n-hexane and toluene.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 An Interior Inverse Generalized Impedance Problem for the Modified Helmholtz Equation in Two Dimensions(Wiley-v C H verlag Gmbh, 2025) Ivanyshyn Yaman, Olha; Ozdemir, Gazi; 04.02. Department of Mathematics; 04. Faculty of Science; 01. Izmir Institute of TechnologyWe consider the inverse interior problem of recovering the surface impedances of the cavity from sources and measurements placed on a curve inside of it. The uniqueness issue is investigated, and a hybrid method is proposed for the numerical solution. The approach takes advantages of both direct and iterative schemes, such as it does not require an initial guess and has an accuracy of a Newton-type method. Presented numerical experiments demonstrate the feasibility and effectiveness of the approach.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.