PubMed İndeksli Yayınlar Koleksiyonu / PubMed Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7645
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Article Citation - WoS: 4Citation - Scopus: 2Elastic and Anelastic Behavior Associated With Structural Transitions in CsPbBr3(Amer Chemical Soc, 2025) Luo, Pingjing; He, Zhengwang; Yang, Dexin; Aktas, Oktay; Ding, Xiangdong; Zhang, XuefengStrain coupling and relaxation dynamics critically influence the photovoltaic and photoluminescent performances of metal halide perovskites. Here, resonant ultrasound spectroscopy is employed to study the elastic and anelastic properties associated with the octahedral tilting transitions in the optoelectronic semiconductor CsPbBr3 over the temperature range 303-468 K. The cubic-to-tetragonal transition near 405 K is marked by pronounced elastic softening accompanied by a sharp increase in acoustic loss. High anelastic loss below this transition reveals the presence of mobile ferroelastic twin walls that become pinned by lead vacancies at a temperature interval near 380 K in the tetragonal phase. The elastic softening in the cubic phase is strongly correlated to dynamic effects such as the local polar fluctuations. This local disordered effect is further verified by the anomalously high attenuation in the orthorhombic structure, in which the ferroelastic twin walls might become mobile.Article Citation - WoS: 3Citation - Scopus: 3Analysis of Microplastic Flux From the Gediz River To the Aegean Sea: a Modeling Study for Environmental Management(Academic Press Ltd- Elsevier Science Ltd, 2025) Kazanci, Yigithan; Alyuruk, Nefise; Alpergun, Cumana; Kara, Nursena; Baycan, Neval; Gunduz, OrhanIt is critical to determine the abundance of microplastics in terrestrial inland waters, understand their fate and transport mechanisms, and reveal their status in aquatic environments. This study aimed to develop and calibrate a mathematical model to simulate microplastic (MP) pollution in the Gediz River Basin, T & uuml;rkiye, which focused on MP fate and transport under existing conditions and various management scenarios. The baseline scenario revealed that, despite a ninefold difference in flow rates, the midstream and upstream parts of the basin also exhibited significant contamination, with an average concentration of 25 n/L compared to the downstream average of 29 n/L. The model was later simulated to test the effects of various mitigation scenarios including but not limited to reducing MP discharges from wastewater treatment plants (WWTPs) and implementing vegetative barriers in tributaries. Scenario 4, which involves reducing MP concentrations in upstream tributaries with vegetative barriers, achieved the highest average reduction across all segments (32 %) and specifically in the downstream area (47 %). In contrast, Scenario 1, aimed at reducing wastewater discharges from urban and industrial WWTPs through water reclamation, and Scenario 2, which focused on eliminating MP in Organized Industrial Zone (OIZ) discharges by changing industrial inputs, achieved the most effective MP reductions in the upper basin, with reductions of 20 % and 17 %, respectively. Scenario 3, targeting flow reduction and accumulation through constructed wetlands, had minimal impact, with reductions close to 0 % in most areas. These results highlight the need for comprehensive approaches to effectively reduce MP pollution, particularly in managing upstream and tributary sources.Article An Analytical Methodology for the Determination of Cadmium Bound To Whey-Proteins by Laser-Induced Breakdown Spectroscopy at Low Pressures(Elsevier, 2026) Erdogrul, Ilayda Yaman; Yalcin, Serife H.In this study, a dried-droplet LIBS methodology for determining cadmium in cow milk has been developed. The performance of the methodology was shown by standard and real protein samples. A standard protein, bovine serum albumin (BSA), and whey protein extracted from skim cow milk were incubated in standard Cd solutions, and the complex solution was filtered through cut-off filters by centrifugation. The unreacted cadmium in the filtrate and Cd-bound protein in the filtered fraction were loaded separately onto a Si-wafer substrate and analyzed via dried-droplet LIBS methodology. Measurements were performed at reduced pressures by taking advantage of the signal enhancement effect. The optimum pressure for most Cd emission lines was found to be 100 mbar. It has been shown that the dried-droplet LIBS methodology at reduced pressures can be used for the identification and determination of free and protein-bound Cd in the whey matrix. The concentration-based detection limit of Cd bound to whey proteins was determined to be 20.2 ng mL- 1, which corresponds to as low as 10 pg in absolute amount with a sample volume of 500 nL. The LOQ value is estimated as 67.3 ng mL- 1 and 33.3 pg, in terms of concentration unit and absolute amount, respectively. The use of small sample volumes is important in the analysis of limited amounts of samples, such as body fluids. Preconcentration studies with multiple loadings of the sample on the same spot resulted in improvements in concentration-based detection. 8 ng mL- 1 Cd in the whey matrix that could not be determined by a single droplet loading due to being below the detection limit; could be determined after 10 consecutive loadings. The methodology may also be applied to the determination of other toxic metals bound to proteins for food quality control.Article Citation - WoS: 3Citation - Scopus: 4Evaluation of in Vivo and in Vitro Toxicity of Chestnut (Castanea Mollissima Blume) Plant: Developmental Toxicity in Zebrafish Embryos Cytotoxicity, Antioxidant Activity, and Phytochemical Composition by LC-ESI-MS/MS(John Wiley and Sons Inc, 2025) Demirtas, Ibrahim; Atalar, Mehmet Nuri; Bingol, Zeynebe; Kokturk, Mine; Ozhan, Gunes; Abdelsalam, Amine Hafis; Gulcin, IlhamiThe search for novel therapeutic agents has led to increasing interest in natural products, driven by the recognition that they may offer safer and more sustainable alternatives to synthetic drugs. This study aims to fill the gap in knowledge regarding the biological activity and safety of the water extract of chestnut (Castanea mollissima) (chestnut), a plant species with a long history of use in traditional medicine, by conducting a comprehensive evaluation of its antioxidant, antidiabetic, and neuroprotective properties. This study presents a comprehensive analysis of the water extract of chestnut for the first time using various bioanalytical antioxidant methods. The extract's inhibitory effects on key enzymes like acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and alpha-glycosidase were evaluated due to their relevance in metabolic and neurodegenerative disorders such as diabetes and Alzheimer's disease. Developmental toxicity and cytotoxicity were assessed using zebrafish (Danio rerio) embryos to evaluate the extract's biological safety. The major phenolic compounds present in the extract were identified by liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS), revealing catechin, gallic acid, taxifolin, and epicatechin as the predominant constituents. Antioxidant capacity was determined through radical scavenging assays using 2,2-diphenyl-1-picrylhydrazyl (DPPH center dot) and 2,2 '-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS center dot+), alongside ferric (Fe3+), cupric (Cu2+), and Fe3+-TPTZ (ferric-tripyridyltriazine) reducing power assays. The findings highlight the significant antioxidant, antidiabetic, and neuroprotective potential of the chestnut water extract, supporting its prospective use in pharmaceutical and nutraceutical applications.Article Citation - WoS: 1Citation - Scopus: 1High-Performance Polyether Sulfone (PES) Membranes Modified With Sunflower Seed Shell-Derived Activated Carbon (SSAC)@zif-11 Nanoparticles for Enhanced Antibiotic Removal and Antifouling Properties(Elsevier, 2025) Alafi, Narges Mortazazad; Barzegar, Behrad; Habibi, Rezvan; Aghdasinia, Hassan; Altinkaya, Sacide Alsoy; Barzegar, B.This study investigates the impact of incorporating a novel composite filler on the antibiotic removal efficiency and protein fouling resistance of polyether sulfone (PES) membranes. The filler was synthesized from activated carbon derived from sunflower seed shells (SSAC) and modified with zeolitic imidazolate framework-11 (ZIF-11). The adsorption capacities of the composite for two model antibiotics, tetracycline (TC) and rifampicin (RP), were evaluated. Mixed matrix membranes were fabricated using the phase inversion method with varying SSAC@ZIF11 contents (0.2-1 wt%). The membrane containing 0.8 wt% SSAC@ZIF-11 exhibited improved structural and surface characteristics, including increased porosity, larger pore size, smoother morphology, and enhanced hydrophilicity, as reflected by a reduction in contact angle from 60.72 degrees to 46.45 degrees. At this optimal loading, the pure water flux increased significantly from 10.52 to 39.1 L/m2h. Moreover, the modified membrane demonstrated outstanding removal efficiencies for TC (99.12 %) and RP (89.9 %), alongside excellent antifouling performance, as indicated by a flux recovery ratio increase from 42.85 % to 99.74 %. These results confirm the potential of SSAC@ZIF-11 as an effective nanofiller for developing high-performance PES membranes in advanced water purification applications.Article Citation - WoS: 2Citation - Scopus: 2Determination of Retrorsine in Thyme Via Molecularly Imprinted Electrochemical Sensor: Validation and Comparison With Chromatographic Technique(Elsevier Sci Ltd, 2025) Tunc-Ata, Melek; Akturk, Ezgi Zekiye; Njjar, Muath; Kaya, Ahmet; Akdogan, Abdullah; Onac, CananPyrrolizidine alkaloid (PA) toxicity is a growing public health concern, especially with rising herbal product use during the pandemic, highlighting the need for accurate exposure data. Retrorsine (RTS), a retronecine-based PA, is highly toxic, causing liver damage, mutagenicity, and DNA cross-linking through metabolic activation. In the light of the need for a practical alternative to monitor pyrrolizidine alkaloid contamination in herbal products, a molecularly-imprinted-polymer sensor (MIPs-GCE) was used for exploring the electrochemical behavior of RTS electrochemical behavior using cyclic voltammetry and the selective detection of RTS using square wave voltammetry. The sensor demonstrated a linear-detection range of 0.05-2 nM, with a LOD of 0.02869 nM. The sensor's accuracy was validated by analyzing thyme samples, detecting RTS concentrations of 0.5168 and0.5345 nM with RSD of 2.4 % and 1.9 %. These results closely aligned LC-MS/MS values of 0.5142 and 0.5267 nM, confirming the sensor's precision. The sensor demonstrated high selectivity, low detection limits, and practical applicability, ensuring reliable and efficient RTS detection in the presence of twenty-eight different PA compounds. This study introduces a novel, reliable, and straightforward method for detecting PAs, with a specific focus on RTS, offering an enhancement to existing analytical techniques and presenting a complementary alternative in chromatographic applications such as LC-MS/MS, HPLC and GC-MS.Article Citation - WoS: 2Citation - Scopus: 2Speciation of Inorganic and Organometallic Arsenic in Various Matrices With a Novel Spme Fiber Functionalized With Iron Nanoparticles Prior To Lc-Icp Determination(Elsevier, 2025) Boyaci, Ezel; Cagir, Ali; Shahwan, Talal; Eroglu, Ahmet E.A novel SPME-LC-ICP-MS methodology is described for the simultaneous microextraction/speciation/determination of the metabolically critical inorganic and organoarsenic species, namely, As(III), As(V), dimethylarsinic acid (DMA), and monomethylarsonic acid (MMA) in natural waters such as drinking and geothermal waters, and biological fluids such as urine. The novelty of the study stems also from the use of home-made SPME fibers for the extraction process, and from the proposed methodology needing no derivatization step. SPME fibers were prepared with in-tube capillary template approach through the immobilization of iron nanoparticles into agarose matrix. The fibers demonstrated reproducible extraction (<10 % RSD), good mechanical strength and good solvent resistivity. The separation of the analytes was realized by HPLC with a strong anion exchange column via gradient elution using different concentrations of (NH4)(2)CO3 (pH 8.50), and the on-line detection of eluted analytes was achieved by ICP-MS. The validity of the proposed methodology was verified via the analysis of certified reference materials (SRM 1643e, Natural Water-Trace Elements, and SRM 2669, Arsenic Species in Frozen Human Urine) and through spike recovery tests. The values of percentage recovery for SRM 2669 were 90.7 % for As(III), 99.8 % for As(V), 93.6 % for DMA, and 85.9 % for MMA. A good correlation was also found between the certified (60.45 mu gL(-1)) and determined (59.00 mu gL(-1)) values for SRM 1643e. Moreover, the speciation capability of the method was demonstrated on various natural waters and biological fluids.Article Citation - WoS: 5Citation - Scopus: 5Magnetically Controllable and Degradable Milliscale Swimmers as Intraocular Drug Implants(Wiley, 2025) Yildiz, E.; Bozuyuk, U.; Yildiz, E.; Wang, F.; Han, M.; Karacakol, A.C.; Sitti, M.Intraocular drug implants are increasingly used for retinal treatments, such as age-related macular degeneration and diabetic macular edema, due to the rapidly aging global population. Although these therapies show promise in arresting disease progression and improving vision, intraocular implant-based therapies can cause unexpected complications that require further surgery due to implant dislocation or uncontrolled drug release. These frequent complications of intraocular drug implants can be overcome using magnetically controllable degradable milliscale swimmers (MDMS) with a double-helix body morphology. A biodegradable hydrogel, polyethylene glycol diacrylate, is employed as the primary 3D printing material of MDMS, and it is magnetized by decorating it with biocompatible polydopamine-encapsulated iron-platinum nanoparticles. MDMS have comparable dimensions to commercial intraocular implants that achieve translational motions in both aqueous and vitreous bodies. They can be imaged in real-time using optical coherence tomography, ultrasound, and photoacoustic imaging. Thanks to their biodegradable hydrogel-based structure, they can be loaded with anti-inflammatory drug molecules and release the medications without disrupting retinal epithelial viability and barrier function, and decrease proinflammatory cytokine release significantly. These magnetically controllable swimmers, which degrade in a couple of months, can be used for less invasive and more precise intraocular drug delivery compared to commercial intraocular drug implants. © 2025 The Author(s). Advanced Science published by Wiley-VCH GmbH.Article Citation - WoS: 1Citation - Scopus: 1Differential Susceptibility and Role for Senescence in Cart Cells Based on Costimulatory Domains(BMC, 2025) Can, Ismail; Siegler, Elizabeth L.; Sirpilla, Olivia L.; Manriquez-Roman, Claudia; Yun, Kun; Stewart, Carli M.; Kenderian, Saad S.Despite the success of chimeric antigen receptor T (CART) cell therapy in hematological malignancies, durable remissions remain low. Here, we report CART senescence as a potential resistance mechanism in 41BB-costimulated CART cell therapy. To mimic cancer relapse, we utilized an in vitro model with repeated CART cell activation cycles followed by rest periods. Using CD19-targeted CART cells with costimulation via 4-1BB-CD3 zeta (BB zeta) or CD28-CD3 zeta (28 zeta), we showed that CART cells undergo functional, phenotypical, and transcriptomic changes of senescence, which is more prominent in BB zeta. We then utilized two additional independent strategies to induce senescence through MYC activation and irradiation. Induction of senescence impaired BB zeta activity but improved 28 zeta activity in preclinical studies. These findings were supported by analyses of independent patient data sets; senescence signatures in CART cell products were associated with non-response to BB zeta but with improved clinical outcomes in 28 zeta treatment. In summary, our study identifies senescence as a potential mechanism of failure predominantly in 41BB-costimulated CART cells.Article Citation - WoS: 2Citation - Scopus: 2Tuning Toxicity Profiles of Graphene Oxide Through Imidazole-Oxime Modification: Zebrafish as a Model System(Oxford Univ Press, 2025) Yildirim, Serkan; Kokturk, Mine; Yigit, Aybek; Sahin, Ayse; Kiliclioglu, Metin; Atamanalp, Muhammed; Alak, GoncaThe increasing use of nanotechnology, especially in agriculture and the food industry, has raised concerns about the possible adverse effects of nanomaterials (NMs) on human health and the environment. This study investigates the effects of synthesized graphene oxide (GO) and its derivatives on zebrafish exposed for 96 hr, focusing on morphological changes in brain tissue, histopathology, and immunofluorescent markers such as 8-hydroxy-2'-deoxyguanosine (8-OHdG) and nucleolar protein 10 (NOP10). Exposure to GO resulted in malformations, DNA damage, and increased NOP10 expression, and it reduced hatching and survival rates. Our results demonstrated that exposure to GO, graphene oxide-oxime (GO-OX), and OX exerted dose-dependent inhibitory effects on hatching and promoted malformations in zebrafish larvae. Histopathological analysis revealed that higher doses led to more pronounced tissue damage, with GO 50 causing severe degeneration and necrosis, while high doses of GO-OX and OX resulted in moderate tissue changes. This was further supported by the increased expression levels of 8-OHdG (marker of oxidative DNA damage) and NOP10 (marker of nucleolar stress), which aligns with the histopathological findings and confirms the neurotoxic effects. Notably, GO-OX treatments consistently mitigated both morphological and neurotoxic effects at all doses, suggesting that oxime functionalization reduces the inherent toxicity of GO. In contrast, treatment with different concentrations of GO-OX derivatives mitigated these adverse effects, reducing them to mild or moderate levels.