WoS İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/394
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Article Citation - WoS: 8Citation - Scopus: 8Thermo-Responsive Complexes of c-Myc Antisense Oligonucleotide With Block Copolymer of Poly(OEGMA) and Quaternized Poly(4-Vinylpyridine)(Wiley-VCH Verlag GmbH, 2016-11-03) Topuzogullari, Murat; Elalmis, Yeliz Basaran; Isoglu, Sevil DincerSolution behavior of thermo-responsive polymers and their complexes with biological macromolecules may be affected by environmental conditions, such as the concentration of macromolecular components, pH, ion concentration, etc. Therefore, a thermo-responsive polymer and its complexes should be characterized in detail to observe their responses against possible environments under physiological conditions before biological applications. To briefly indicate this important issue, thermo-responsive block copolymer of quaternized poly(4-vinylpyridine) and poly(oligoethyleneglycol methyl ether methacrylate) as a potential nonviral vector has been synthesized. Polyelectrolyte complexes of this copolymer with the antisense oligonucleotide of c-Myc oncogene are also thermo-responsive but, have lower LCST (lower critical solution temperature) values compared to individual copolymer. LCST values of complexes decrease with molar ratio of macromolecular components and presence of salt. Dilution of solutions also affects solution behavior of complexes and causes a significant decrease in size and an increase in LCST, which indicates possible effects of severe dilutions in the blood stream.Article Citation - WoS: 15Citation - Scopus: 16Quartz-Crystal Microbalance Measurements of Cd19 Antibody Immobilization on Gold Surface and Capturing B Lymphoblast Cells: Effect of Surface Functionalization(Wiley-VCH Verlag GmbH, 2018-02-05) Icoz, Kutay; Soylu, Mehmet Cagri; Canikara, Zeynep; Unal, EkremWe have investigated different surface functionalization methods to immobilize CD19 antibody on gold surface to capture B lymphoblast cells associated with the acute lymphoblastic leukemia disease. Quartz Crystal Microbalance measurements were performed to analyze the binding kinetics of each layer and determine the optimum method, which results in higher cell capture rates. The random orientation of antibody and oriented antibody through protein G was investigated and protein G presence resulted in 15,2Hz frequency shift for 10(4)cells/mL. The 3-mercaptopropyltrimethoxysilane (MPS) and 11-Mercaptoundecanoic acid (MUA) coatings of gold surface together with 4-(N-Maleimidomethyl)cyclohexane-1-carboxylic acid 3-sulfo-N-hydroxysuccinimide ester sodium salt (Sulfo-SMCC) and N-Ethyl-N'-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC)/N-hydroxysulfosuccinimide (NHS) linker layers were tested on QCM for protein G and antibody binding. The results indicate that MUA, EDC/NHS, protein G, antibody CD19 is the optimum surface modification among the tested combinations. By using the optimum surface functionalization method, minimum 10(3) cell per mL was measured as 1.9Hz frequency shift.Article Citation - WoS: 13Citation - Scopus: 14HER2-Targeted, Degradable Core Cross-Linked Micelles for Specific and Dual pH-Sensitive Dox Release(Wiley-VCH Verlag GmbH, 2021-11-09) Bayram, Nazende Nur; Ulu, Gizem Tugce; Topuzogullari, Murat; Baran, Yusuf; Isoglu, Sevil Dincer; Dinçer İşoğlu, SevilHere, a targeted, dual-pH responsive, and stable micelle nanocarrier is designed, which specifically selects an HER2 receptor on breast cancer cells. Intracellularly degradable and stabilized micelles are prepared by core cross-linking via reversible addition-fragmentation chain-transfer (RAFT) polymerization with an acid-sensitive cross-linker followed by the conjugation of maleimide-doxorubicin to the pyridyl disulfide-modified micelles. Multifunctional nanocarriers are obtained by coupling HER2-specific peptide. Formation of micelles, addition of peptide and doxorubicin (DOX) are confirmed structurally by spectroscopical techniques. Size and morphological characterization are performed by Zetasizer and transmission electron microscope (TEM). For the physicochemical verification of the synergistic acid-triggered degradation induced by acetal and hydrazone bond degradation, Infrared spectroscopy and particle size measurements are used. Drug release studies show that DOX release is accelerated at acidic pH. DOX-conjugated HER2-specific peptide-carrying nanocarriers significantly enhance cytotoxicity toward SKBR-3 cells. More importantly, no selectivity toward MCF-10A cells is observed compared to HER2(+) SKBR-3 cells. Formulations cause apoptosis depending on Bax and Caspase-3 and cell cycle arrest in G2 phase. This study shows a novel system for HER2-targeted therapy of breast cancer with a multifunctional nanocarrier, which has higher stability, dual pH-sensitivity, selectivity, and it can be an efficient way of targeted anticancer drug delivery.Article Citation - WoS: 10Citation - Scopus: 8Ensemble Feature Selection for Clustering Damage Modes in Carbon Fiber-Reinforced Polymer Sandwich Composites Using Acoustic Emission(Wiley-VCH Verlag GmbH, 2024-07-15) Gulsen, Abdulkadir; Kolukisa, Burak; Caliskan, Umut; Bakir-Gungor, Burcu; Gungor, Vehbi CagriAcoustic emission (AE) serves as a noninvasive technique for real-time structural health monitoring, capturing the stress waves produced by the formation and growth of cracks within a material. This study presents a novel ensemble feature selection methodology to rank features highly relevant with damage modes in AE signals gathered from edgewise compression tests on honeycomb-core carbon fiber-reinforced polymer. Two distinct features, amplitude and peak frequency, are selected for labeling the AE signals. An ensemble-supervised feature selection method ranks feature importance according to these labels. Using the ranking list, unsupervised clustering models are then applied to identify damage modes. The comparative results reveal a robust correlation between the damage modes and the features of counts and energy when amplitude is selected. Similarly, when peak frequency is chosen, a significant association is observed between the damage modes and the features of partial powers 1 and 2. These findings demonstrate that, in addition to the commonly used features, other features, such as partial powers, exhibit a correlation with damage modes. This article presents a novel ensemble feature selection methodology to rank features relevant to damage modes on acoustic emission signals in carbon fiber-reinforced polymer sandwich composites. Subsequently, ranked features are utilized in unsupervised clustering models to identify damage modes. The comparative results demonstrate that, along with common features, other features, like partial powers, have a robust correlation with damage modes.image (c) 2024 WILEY-VCH GmbHArticle Citation - WoS: 5Citation - Scopus: 5Development of Buckwheat Starch-Capric Acid Complex-Based Film: Process Optimization and Film Characterization(Wiley-VCH Verlag GmbH, 2025-02-26) Koca, Esra; Kahraman, Kevser; Oskaybas-Emlek, Betul; Ozbey, Ayse; Aydemir, Levent YurdaerTo overcome the limitations of starch usage alone, the film formation ability of the buckwheat starch-capric acid complex (BS-CA) was optimized, and the films were characterized. Significant models were obtained for tensile strength (TS) and Young's modulus (YM) of BS-CA film (p < 0.0001). The glycerol/starch ratio, temperature, and their interactions were significant in the YM model (R-2 is 0.9851). The BS-CA film had a better water vapor barrier (0.463 +/- 0.02 g mm/m(2) h kPa), with lower water solubility (WS) (34.18 +/- 1.70%) and moisture content (MC) (16.87 +/- 0.09%) than the buckwheat starch (BS) film (p < 0.05). It had lower thickness (0.073 +/- 0.00 mm) and TS (0.624 +/- 0.04 MPa) but higher elasticity (114.60 +/- 3.12%). The non-covalent interactions were determined between BS and CA, since new peaks were not observed in the film's FTIR spectrum. BS-CA film had a typical V-type crystalline structure and had slightly lower decomposition temperatures than the BS film. Contact angle measurements (55.19 degrees +/- 1.7), and images of AFM topography and SEM showed that the BS-CA film surface was hydrophilic; height and average roughness values were 1014 and 276 nm, respectively, which were quite higher than those of BS film. The results reveal that starch modification with fatty acid is a promising way to develop starch-based films to be used in practical applications.Article Citation - WoS: 110Citation - Scopus: 116Bodipy-Based Semiconducting Materials for Organic Bulk Heterojunction Photovoltaics and Thin-Film Transistors(Wiley-VCH Verlag GmbH, 2018-12-13) Ho, Dongil; Ozdemir, Resul; Kim, Hyungsug; Earmme, Taeshik; Usta, Hakan; Kim, ChoongikThe rapid emergence of organic (opto)electronics as a promising alternative to conventional (opto)electronics has been achieved through the design and development of novel pi-conjugated systems. Among various semiconducting structural platforms, 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) pi-systems have recently attracted attention for use in organic thin-films transistors (OTFTs) and organic photovoltaics (OPVs). This Review article provides an overview of the developments in the past 10 years on the structural design and synthesis of BODIPY-based organic semiconductors and their application in OTFT/OPV devices. The findings summarized and discussed here include the most recent breakthroughs in BODIPYs with record-high charge carrier mobilities and power conversion efficiencies (PCEs). The most up-to-date design rationales and discussions providing a strong understanding of structure-property-function relationships in BODIPY-based semiconductors are presented. Thus, this review is expected to inspire new research for future materials developments/applications in this family of molecules.Article Citation - WoS: 3Citation - Scopus: 3An Experimental and Numerical Study of the Exchange Current Density in an HTPEM Fuel Cell(Wiley-VCH Verlag GmbH, 2021-09-18) Celik, Murat; Elden, GulsahThe purpose of this study is to examine the effects of exchange current density, as dependent on operating parameters, on the activation polarization in an HTPEM fuel cell. In line with this purpose, cell performance tests were performed for different relative humidity levels (from 0 to 20% in steps of 5%) and six different acid doping levels (4.26, 4.53, 4.95, 5.51, 7.24, 7.51 H3PO4/RPU PBI) at constant cell temperature (120 degrees C). The exchange current densities, as dependent on acid doping level and relative humidity, were determined by fitting a zero-dimensional steady-state mathematical model to the cell performance test results. Finally, to investigate the activation polarization in the cell, the exchange current densities obtained were incorporated within a numerical model. The results show that the effects of relative humidity on the exchange current density are relatively limited at all acid doping levels when the relative humidity is greater than 5%. The exchange current densities exhibit a decreasing trend with increasing acid doping level. Furthermore, it was found that the acid doping level and relative humidity have a strong influence on the anode overpotential, whereas no significant effect on the cathode overpotential was observed.Article Citation - WoS: 19Citation - Scopus: 20A Solution-Processable Meso-Phenyl N-Channel Semiconductor With Enhanced Fluorescence Emission(Wiley-VCH Verlag GmbH, 2019-06-26) Ozcan, Emrah; Ozdemir, Mehmet; Ho, Dongil; Zorlu, Yunus; Ozdemir, Resul; Kim, Choongik; Cosut, BunyeminThe cover feature shows the delicate balance between locally excited (LE) and twisted intramolecular charge-transfer (TICT) states, which could be controlled by solvent polarity and nano-aggregation, of a meso-phenyl-BODIPY-based fluorescent semiconductor. The dihedral angle between the meso-aromatic unit and BODIPY pi-core was found to be the key factor in this balance. This is the first report of highly emissive characteristics for an A-D-A type BODIPY-based n-channel semiconductor. Details are given in the Full Paper by B. Cosut, H. Usta, C. Kim, and co-workers (DOI: 10.1002/cplu.201900317).