Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article A Novel Technique Using Integral Transforms and Residual Functions for Nonlinear Partial Fractional Differential Equations Involving Caputo Derivatives(Public Library of Science, 2024) Khan, Z.A.; Riaz, M.B.; Liaqat, M.I.; Akgül, A.Fractional nonlinear partial differential equations are used in many scientific fields to model various processes, although most of these equations lack closed-form solutions. For this reason, methods for approximating solutions that occasionally yield closed-form solutions are crucial for solving these equations. This study introduces a novel technique that combines the residual function and a modified fractional power series with the Elzaki transform to solve various nonlinear problems within the Caputo derivative framework. The accuracy and effectiveness of our approach are validated through analyses of absolute, relative, and residual errors. We utilize the limit principle at zero to identify the coefficients of the series solution terms, while other methods, including variational iteration, homotopy perturbation, and Adomian, depend on integration. In contrast, the residual power series method uses differentiation, and both approaches encounter difficulties in fractional contexts. Furthermore, the effectiveness of our approach in addressing nonlinear problems without relying on Adomian and He polynomials enhances its superiority over various approximate series solution techniques. © 2024 Khan et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Article Citation - WoS: 6Citation - Scopus: 6Effect of the Synthesis Method and Particle Size on Bczt Electrocaloric Properties(Pergamon-elsevier Science Ltd, 2025) Temel, Helin; Avci, Tubanur; Okatan, M. Baris; Alkoy, Sedat; Misirlioglu, I. Burc; Mensur, EbruIn this study, the electrocaloric properties of BCZT ceramics fabricated through different processing methods: solid-state and sol-gel were investigated. The calcination process was done for BCZT powders obtained by sol-gel process at 900 degrees C for 2 h and by solid-state calcination method at 1200 degrees C for 6 h. BCZT-SG ceramics exhibited higher Delta T values, particularly at lower temperatures (similar to 0 degrees C-20 degrees C), and a stronger response to the electric field, suggesting a more efficient domain structure due to sol-gel processing. Notably, BCZT-SGH samples demonstrated the most complex and pronounced electrocaloric behavior, with dual Delta T peaks around 0 degrees C and 50 degrees C, and the highest Delta T of 2.5 K at 80 kV/cm and 50 degrees C, surpassing values in the literature. Especially, high Delta T results at 0 degrees C allows using this material in the extreme conditions. These results emphasize the significant role of processing techniques in tailoring the structural, dielectric, and electrocaloric properties of BCZT ceramics for high-performance energy applications.Article Citation - WoS: 2Citation - Scopus: 2Fabrication of Bioactive Helix Aspersa Extract-Loaded Chitosan-Based Bilayer Wound Dressings for Skin Tissue Regeneration(Amer Chemical Soc, 2024) Perpelek, Merve; Tıhmınlıoğlu, Funda; Tamburaci, Sedef; Karakasli, Ahmet; Tihminlioglu, FundaIn recent years, there has been a notable shift toward exploring plant and animal extracts for the fabrication of tissue engineering structures that seamlessly integrate with the human body, providing both biological compatibility and physical reinforcement. In this particular investigation, we synthesized bilayer wound dressings by incorporating snail (Helix aspersa) secretions, comprising mucus and slime, into chitosan matrices via lyophilization and electrospinning methodologies. A nanofiber layer was integrated on top of the porous structure to mimic the epidermal layer for keratinocyte activity as well as acting as an antibacterial barrier against possible infection, whereas a porous structure was designed to mimic the dermal microenvironment for fibroblast activity. Comprehensive assessments encompassing physical characterization, antimicrobial efficacy, in vitro bioactivity, and wound healing potential were conducted on these bilayer dressings. Our findings revealed that the mucus and slime extract loading significantly altered the morphology in terms of nanofiber diameter and average pore size. Snail extracts loaded on a nanofiber layer of bilayer dressings showed slight antimicrobial activity against Staphylococcus epidermidis and Escherichia coli. An in vitro release study of slime extract loaded in the nanofiber layer indicated that both groups 1 and 2 showed a burst release up to 6 h, and a sustained release was observed up to 96 h for group 1, whereas slime extract release from group 2 continued up to 72 h. In vitro bioactivity assays unveiled the favorable impact of mucus and slime extracts on NIH/3T3 fibroblast and HS2 keratinocyte cell attachment, proliferation, and glycosaminoglycan synthesis. Furthermore, our investigations utilizing the in vitro scratch assay showcased the proliferative and migratory effects of mucus and slime extracts on skin cells. Collectively, our results underscore the promising prospects of bioactive snail secretion-loaded chitosan constructs for facilitating skin regeneration and advancing wound healing therapies.Article Citation - WoS: 1Comparison of Cell-Penetrating and Fusogenic Tat-Ha2 Peptide Performance in Peptideplex, Multicomponent, and Conjugate Sirna Delivery Systems(Amer Chemical Soc, 2024) Uz, Metin; Bulmus, Volga; Altinkaya, Sacide AlsoyIn this study, the performance of the cell-penetrating and fusogenic peptide, TAT-HA2, which consists of a cell-permeable HIV trans-activator of transcription (TAT) protein transduction domain and a pH-responsive influenza A virus hemagglutinin protein (HA2) domain, was comparatively evaluated for the first time in peptideplex, multicomponent, and conjugate siRNA delivery systems. TAT-HA2 in all three systems protected siRNA from degradation, except in the conjugate system with a low Peptide/siRNA ratio. The synergistic effect of different peptide domains enhanced the transfection efficiency of multicomponent and conjugate systems compared to that of peptideplexes, which was attributed to the surface configuration of TAT-HA2 peptides depending on the nature of attachment. Particularly, the multicomponent system showed better cellular uptake and endosomal escape than the peptideplexes, resulting in enhanced siRNA delivery in the cytoplasm. In addition, the presence of cleavable disulfide bonds in multicomponent and conjugate systems promoted the effective siRNA delivery in the cytoplasm, resulting in improved gene silencing activity. The multicomponent system reduced the level of luciferase expression in SKOV3 cells to 45% (+/- 4). In contrast, the conjugate system and the commercially available siRNA transfection agent, Lipofectamine RNAiMax, caused luciferase suppression down to 55% (+/- 2) at a siRNA dose of 100 nM. For the same dose, the peptideplex system could only reduce the luciferase expression to 65% (+/- 5). None of the developed systems showed significant toxicity at any dose. Overall, the TAT-HA2 peptide is promising as a siRNA delivery vector; however, its performance depends on the nature of attachment and, as a result, its surface configuration on the developed delivery system.Correction Diaph1-Deficiency Is Associated With Major T, Nk and Ilc Defects in Humans (vol 44, 175, 2024)(Springer/plenum Publishers, 2025) Azizoglu, Zehra Busra; Babayeva, Royala; Haskologlu, Zehra Sule; Acar, Mustafa Burak; Ayaz-Guner, Serife; Okus, Fatma Zehra; Eken, Ahmet[No Abstract Available]Article Citation - WoS: 4Citation - Scopus: 4Tailored Bodipy-Based Fluorogenic Probes for Phosgene Detection: a Comparative Evaluation of Recognition Sites(Royal Soc Chemistry, 2024) Dartar, Suay; Kaya, Beraat Umur; Yayak, Yanki Oncu; Vural, Ezgi; Emrullahoglu, MustafaWe constructed two novel boron-dipyrromethene (BODIPY)-based fluorescent probes, BOPD and BOBA, each equipped with the phosgene specific recognition units o-phenylenediamine (OPD) and o-aminobenzylamine (OBA) at the 2-position of the BODIPY core. BOPD and BOBA represent rare examples of BODIPY-based probes that operate by modulating an intramolecular charge transfer process (ICT), as validated by computational studies. We systematically compared the analytic performance of those recognition units while focusing on selectivity, fluorescence turn-on ratios and response times. Probe BOBA, equipped with OBA as the recognition unit, demonstrated a remarkably low detection limit (i.e., 1.40 nM) and a rapid response time (<10 s) for triphosgene. By comparison, BOPD, featuring an OPD unit, showed superior selectivity towards triphosgene, with a detection limit of 93 nM and a response time of up to 30 s. A portable sensing platform was developed by loading BOPD onto test strips made of TLC plates, nonwoven materials and small-headed cotton swabs, which were assessed for their effectiveness in detecting phosgene. We additionally performed the first successful application of a fluorescent probe, namely BOPD, for monitoring the accumulation of phosgene in plants.Article Citation - WoS: 2Citation - Scopus: 2Stabilization of the First-Order Phase Transition Character and Enhancement of the Electrocaloric Effect by Na<sub>0.5</Sub>bi<sub>0.5< Substitution in Batio<sub>3</Sub> Ceramics(Royal Soc Chemistry, 2024) Karakaya, Merve; Gurbuz, Irem; Fulanovic, Lovro; Adem, UmutThe electrocaloric properties of BaTiO3-based Pb-free ferroelectric materials are widely investigated. One approach to achieving a large electrocaloric response is making use of the substantial polarization change associated with the first-order phase transition at the Curie temperature. To make use of this approach, we have investigated the electrocaloric response of (1 - x)BaTiO3-xNa0.5Bi0.5TiO3 (BT-NBT) ceramics for x = 0.05, 0.10, 0.20 and 0.30. For this BT-rich part of the solid solution, it is established that increasing the NBT content increases the tetragonality of the BaTiO3. We show that this increase in tetragonality with NBT substitution helps to maintain the first-order nature of the phase transition in BaTiO3 and correspondingly a large electrocaloric response, despite the simultaneous enhancement of relaxor ferroelectric character with the NBT substitution. A significantly larger effective electrocaloric temperature change (Delta Teff) of 1.65 K was obtained for the x = 0.20 sample under 40 kV cm-1, using the direct measurement of the electrocaloric effect, which is in reasonable agreement with the indirect measurements.Article Citation - WoS: 2Citation - Scopus: 1Gliflozins, Sucrose and Flavonoids Are Allosteric Activators of Lecithin-Cholesterol Acyltransferase(Nature Portfolio, 2024) Niemela, Akseli; Giorgi, Laura; Nouri, Sirine; Yurttas, Betul; Rauniyar, Khushbu; Jeltsch, Michael; Koivuniemi, ArtturiLecithin-cholesterol acyltransferase (LCAT) serves as a pivotal enzyme in preserving cholesterol homeostasis via reverse cholesterol transport, a process closely associated with the onset of atherosclerosis. Impaired LCAT function can lead to severe LCAT deficiency disorders for which no pharmacological treatment exists. LCAT-based therapies, such as small molecule positive allosteric modulators (PAMs), against LCAT deficiencies and atherosclerosis hold promise, although their efficacy against atherosclerosis remains challenging. Herein we utilized a quantitative in silico metric to predict the activity of novel PAMs and tested their potencies with in vitro enzymatic assays. As predicted, sodium-glucose cotransporter 2 (SGLT2) inhibitors (gliflozins), sucrose and flavonoids activate LCAT. This has intriguing implications for the mechanism of action of gliflozins, which are commonly used in the treatment of type 2 diabetes, and for the endogenous activation of LCAT. Our results underscore the potential of molecular dynamics simulations in rational drug design.Article Citation - WoS: 4Citation - Scopus: 4Organolabeler: a Quick and Accurate Annotation Tool for Organoid Images(Amer Chemical Soc, 2024) Kahveci, Burak; Polatli, Elifsu; Bastanlar, Yalin; Guven, SinanOrganoids are self-assembled 3D cellular structures that resemble organs structurally and functionally, providing in vitro platforms for molecular and therapeutic studies. Generation of organoids from human cells often requires long and costly procedures with arguably low efficiency. Prediction and selection of cellular aggregates that result in healthy and functional organoids can be achieved by using artificial intelligence-based tools. Transforming images of 3D cellular constructs into digitally processable data sets for training deep learning models requires labeling of morphological boundaries, which often is performed manually. Here, we report an application named OrganoLabeler, which can create large image-based data sets in a consistent, reliable, fast, and user-friendly manner. OrganoLabeler can create segmented versions of images with combinations of contrast adjusting, K-means clustering, CLAHE, binary, and Otsu thresholding methods. We created embryoid body and brain organoid data sets, of which segmented images were manually created by human researchers and compared with OrganoLabeler. Validation is performed by training U-Net models, which are deep learning models specialized in image segmentation. U-Net models, which are trained with images segmented by OrganoLabeler, achieved similar or better segmentation accuracies than the ones trained with manually labeled reference images. OrganoLabeler can replace manual labeling, providing faster and more accurate results for organoid research free of charge.Article Citation - WoS: 5Citation - Scopus: 5An Experimental and Comparative Study on Passive and Active Pcm Cooling of a Battery With/Out Copper Mesh and Investigation of Pcm Mixtures(Elsevier, 2024) Samancioglu, Umut Ege; Gocmen, Sinan; Madani, Seyed Saeed; Ziebert, Carlos; Nuno, Fernando; Huang, Jack; Cetkin, ErdalThe carbon emission contribution to global warming accelerated both research on and transition to electric vehicles (EVs). Drivers demand high power, fast acceleration and less charging times. All these demands require high C rate charging/discharging demands from batteries. The rate of heat generation is exponentially proportional to C rates which decreases battery lifetime and may lead to thermal runaway. However, a battery thermal management system decreases thermal runaway risk and decelerates battery degradation via controlling battery temperature. In this paper, we first document the thermal conductivity enhancement via copper foam into phase change material (PCM) domain to uncover their possible use in EV thermal management applications. Maximum 15.93 times increment is achieved with a specific copper foam. Then, physical properties and behaviors of distinct PCM mixtures are documented. Homogeneity of mixtures is associated with the chemistry of PCMs and the mixture melting point is proportional to the volume weighted average of melting temperatures. The results document that the PCM with relatively lower melting point is beneficial when end of discharge temperatures considered, except for high discharge rate of 2C. Temperature uniformity across the battery increases with relatively higher melting point PCM. Experiments also document that the amount of PCM volume lost via insertion of copper foam yields higher end of discharge temperatures. Overall, both PCM and copper foam enhances temperature homogeneity and their benefit becomes more sensible during drive cycles relative to continuous charge/discharge use cases.