WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7150
Browse
200 results
Search Results
Now showing 1 - 10 of 200
Article Citation - Scopus: 1Adulteration of Pomegranate Molasses With Sugar Syrups: Application of FTIR-ATR Spectroscopy and Chemometrics(Elsevier, 2025) Kilinc, Gizem Simge; Uncu, Oguz; Eren, Ismail; Bagdatlioglu, NerimanIn this study, it was aimed to determine the adulteration ratio of pomegranate molasses (PM) with sugar syrups by using FTIR spectroscopy based upon chemometrics. With this intention, 34 pure PM samples were supplied from local manufacturers and adulterated with high fructose corn syrup (HFCS), glucose-fructose syrup (GFS) and beet sugar syrup (BSS) in varying ratios (5-50 %, w/w). Authentic and adulterated PM samples were analyzed in the range of 4000 and 400 cm(-1) wavenumber by FTIR spectroscopy. PCA was applied as a pretreatment for classification and regression analysis to select the spectral region and data reduction. Whereby the DD-SIMCA models were created using this information. The adulterated and authentic samples were classified correctly by the developed DD-SIMCA models. In the calibration and prediction model of DD-SIMCA, authentic and adulterated PM samples were correctly classified with high sensitivity (>= 0.91) and specificity (>= 0.94), and a clear distinction was observed with high efficiency (>= 0.94). Adulteration rates in PM samples were determined by PLS-R analysis. The correlation coefficients (R-2 >= 0.98) of models were also found quite high. As a consequence, FTIR spectroscopy in conjunction with chemometric approaches could be applied as a quick, dependable, non-destructive, and environmentally friendly tool for categorizing, distinguishing, and quantifying adulteration rates in PM samples.Article Functional Manipulation of Nonspherical Nanoparticles With Cascaded Reconfigurable Modules(Elsevier, 2025) Arslanyurek, Seyma; Dinleyici, Mehmet SalihSelective nanoparticle sorting is essential for applications requiring monodisperse distributions, yet conventional methods lack adaptability for shape-based separation. This study introduces a reconfigurable optical manipulation technique that dynamically sorts spherical and non-spherical nanoparticles using cascaded modules based on evanescent fields. Optical forces were calculated using the Discrete Dipole Approximation (DDA) method, enabling the modeling of various particle shapes and accurately capturing rotational and translational movements. Two cascaded strategies are proposed: the first approach enables fluid-assisted filtration by selectively trapping spherical particles while allowing non-spherical ones to be carried away by the flow. The second strategy first induces the rotational alignment of particles and then employs a trapping mechanism that selectively retains specific geometries, enabling the separation of spherical and non-spherical nanoparticles. Unlike traditional approaches, this method enables high-precision, shape-selective separation without external flow modifications. The results demonstrate unprecedented control and efficiency in nanoparticle sorting, offering a scalable, high-throughput solution for microfluidic and optofluidic applications.Article Citation - WoS: 3Citation - Scopus: 3Design, Synthesis, Characterization and Biological Evaluation of Cobalt-Ferrite Nanoparticles for Biomedical Applications(Elsevier, 2025) Esmer, Ecem Fatma; Bilgi, Eyup; Dincay, Selin Cesmeli; Sakalli, Tugce; Karakus, Ceyda OkselCobalt-Ferrite nanoparticles (CF NPs) are increasingly used in biomedical applications due to their unique magnetic properties and biocompatibility. In this study, CF NPs were synthesized via co-precipitation, both in the presence and absence of oleic acid (OA) as a surfactant. Plackett-Burman Design was employed to study the influence of reaction conditions on the particle size distribution of bare and OA-coated CF NPs. Representative bare and OA-coated CF NP samples were characterized for morphology, composition, thermal stability, and optical and magnetic properties using TEM, XRD, FTIR, TGA, UV-Vis, and VSM. The highest saturation magnetization value (similar to 44 emu/g) was observed for bare CF NPs of smaller sizes. MTT assay results indicated that none of the tested samples showed significant cytotoxicity at the concentrations tested (1, 10, and 100 mu g/mL), except for the bare CF NPs, which reduced viability of A549 cells to approximately 50 % following 72-hour exposure at 100 mu g/mL. Following incubation in a cell culture medium for 48 h, proteins bound to the surface of CF NPs were analyzed using SDS-PAGE, revealing bovine serum albumin, apolipoprotein A-I and fibronectin as the most abundant proteins across samples. Overall, OA-coating slightly improved colloidal stability and reduced cytotoxicity, without significantly compromising the magnetic or protein-binding properties.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: 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 Synthesis, Characterization, Crystal Structure, Electrochemical and Photoluminescence Properties, Dft and Molecular Docking Studies, and Antimicrobial Activities of Two Mononuclear Nickel (II) Complexes With Pyrazole-Derived Ligands(Elsevier, 2025) Amin, Mina A.; Diker, Halide; Sahin, Onur; Varlikli, Canan; Soliman, Ahmed A.Two octahedral nickel complexes; [Ni(fdtp)2(DMF)2] (1) and [Ni(dcdtp)2(DMF)2] (2), based on 4-((3-fluorophenyl)diazenyl)-3-(trifluoromethyl)-1H-pyrazol-5-ol (fdtp) and 4-((2,4-dichlorophenyl)diazenyl)-3-(trifluoromethyl)-1H-pyrazol-5-ol (dcdtp) were synthesized. The complexes were characterized spectroscopically (FTIR, UV-Vis, Photoluminescence), Mass spectrometry, elemental analyses, electrochemically, thermally, and through Single-crystal X-ray investigations. The formation of the complexes was confirmed by the existence of Ni-O and Ni-N vibrations at bonds were observed as weak bands at 526-497 and 470-438 cm-1. According to the thermogravimetric analyses, the complexes were thermally stable and had relatively high activation energies (585.81 and 730.07 kJ mol-1 for 1, and 2, respectively). Cyclic voltammograms showed that the anodic potential region of 1 and 2 exhibited two irreversible oxidation peaks at 1.34 V &1.55 V and 1.41 V & 1.63 V, respectively, attributed to metal-localized oxidation. The complexes showed enhanced antibacterial activities compared to free ligands and comparable to the standard. The inhibition zones exhibited via 1 were about 21.7, 19.3, and 26.7 mm versus Escherichia coli (E. coli), Staphylococcus aureus (S. Aureus), and Bacillus Subtits (B. Subtits), respectively. Docking studies supported the antibacterial investigations; the binding energies of the complexes were -8.81 and -9.69 kcal/mol for 1 and 2 respectively, against E. coli (PDB ID: 6F86).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 Ti-Cu Dry Electrodes for Biomedical Sensing: Tribocorrosion Performance Under Simulated Skin Conditions(Elsevier, 2025) Alves, A. C.; Lopes, C.; Camarinha, A.; Geraldo, D.; Toptan, F.; Ferreira, A.; Vaz, F.Monitoring electromyographic (EMG) activity is crucial for diagnosing musculoskeletal disorders and understanding neuromuscular systems. Dry electrodes represent a significant advancement over traditional wet electrodes by eliminating the need for gels, thereby extending lifespan, simplifying skin preparation, and facilitating prolonged remote monitoring. However, challenges such as higher impedance and susceptibility to motion artifacts, along with issues of user discomfort and signal distortion, persist with existing metal-coated or entirely metal dry electrodes. This study explores an alternative approach using Ti-Cu thin films deposited on polymeric substrates to enhance electrical, electrochemical, and tribo-electrochemical properties. The research specifically investigates the corrosion and tribocorrosion behaviour of these Ti-Cu thin films in an artificial sweat environment, comparing them to pure Ti and Cu films. Chemical, microstructural, topographical, and electrical characterizations were conducted, alongside evaluations of electrochemical and tribo-electrochemical behaviour. The results indicate that while all films showed rupture under sliding, TiCu0.34 thin films exhibited superior corrosion resistance due to their unique microstructure. This study suggests that TiCu0.34 electrodes may offer a promising balance between corrosion resistance and electrical performance for wearable applications, although improvements in adhesion are necessary to withstand mechanical loads.Article Citation - WoS: 1Derivation of Soil Hydraulic Properties (SHPS) Using a Physics-Based Inverse Calibration Method and International Soil Moisture Network Database(Elsevier, 2025) Sahin, Onur Gungor; Gunduz, OrhanThis study used extensive soil moisture records to estimate "inverse-calibrated Soil Hydraulic Properties (SHPs)" using a multi-processing technique via high-performance computing clusters. Within this objective, a mass conservative numerical model was developed to solve the one-dimensional Richards Equation incorporating two different soil hydraulic models: the well-known van Genuchten Mualem (VGM) model and the relatively new Fredlund-Xing-Wang (FXW). A multiprocessing version of the Differential Evolution Algorithm (DEA) optimization technique was used for inverse calibration of the soil hydraulic parameters. For FXW, calibration statistics were calculated as means of the KGE' (0.89 f 0.1 and 0.83 f 0.23), R (0.89 f 0.1 and 0.85 f 0.21) and ubRMSE (0.017 f 0.01 and 0.015 f 0.02) for the depths 50 and 100 cm, respectively. For VGM, calibration statistics were found as means of the KGE' (0.87 f 0.11 and 0.78 f 0.22), R (0.90 f 0.08 and 0.86 f 0.17) and ubRMSE (0.019 f 0.01 and 0.017 f 0.01) for the same depths, respectively. The employed methodology had highly promising statistical performance for both FXW and VGM to derive SHPs. A comprehensive validation methodology was used to evaluate the reliability of derived SHPs. Correlation analysis showed that derived SHPs strongly correlated with the soil properties and environmental variables. Further, as a validation procedure, initial investigations were also conducted to explore the spatial transferability of the parameters. Despite the use of basic k-means clustering, the resulting soil hydraulic datasets showed statistical similarity or even improvement to hyper-resolution maps used in the literature. While the simulation model of the methodology has certain assumptions and limitations, this study proves that the ISMN database can be used to derive soil hydraulic properties and transfer these parameters to locations other than the calibration points. This study shows that FXW is a promising hydraulic model for the determination of soil moisture at root zone within the complete moisture range. The methodology can also be readily extended to other established soil moisture monitoring networks and potentially extended versions of "inverse-calibrated SHPs" and trained pedotransfer functions are considered to be valuable tools to estimate soil moisture profiles at the root zone.Article Citation - WoS: 3Citation - Scopus: 3An Ex Vivo Model for Evaluation of Prebiotic Activity of Xylan and Xylooligosaccharides(Elsevier, 2025) Sabanci, Kevser; Gulec, Sukru; Buyukkileci, Ali OguzEx vivo techniques can provide more physiologically significant insights into prebiotic activity and overcome some limitations of in vitro tests. In this study, an ex vivo model, formed of a large intestine of mice, was tested to assess the effects of the hydrocolloidal natural polymer, xylan (XY), and its hydrolysis product, xylooligosaccharides (XOS). XY and XOS were loaded separately into the cecum, proximal colon, and distal colon. Their utilization and short-chain fatty acid (SCFA) formation by the colonized microflora and levels of dominant phyla and key genera such as Bifidobacterium, Bacteroides, and Lactobacillus were followed. XY and XOS were metabolized in all sections, and SCFAs were released. The results suggest that the slower utilization of XY compared to XOS in the cecum can enable this polysaccharide to move towards distal parts of the large intestine and extend the sites of prebiotic activity. Unlike widely used in vitro models, the ex vivo model allowed testing the utilization pattern and effects of the prebiotics in the natural environment of the microflora and examining the intestinal sections separately.