47 results
Search Results
Now showing 1 - 10 of 47
Article Citation - WoS: 37Citation - Scopus: 45Study on the Cytocompatibility, Mechanical and Antimicrobial Properties of 3d Printed Composite Scaffolds Based on Pva/ Gold Nanoparticles (aunp)/ Ampicillin (amp) for Bone Tissue Engineering(Elsevier, 2021) Topsakal, Aysenur; Midha, Swati; Yuca, Esra; Tukay, Ari; Sasmazel, Hilal Turkoglu; Kalaskar, Deepak M.; Gunduz, OguzhanOver the years, gold nanoparticles (AuNP) have been widely used in several biomedical applications related to the diagnosis, drug delivery, bio-imaging, photo-thermal therapy and regenerative medicine, owing to their unique features such as surface plasmon resonance, fluorescence and easy surface functionality. Recent studies showed that gold nanoparticles display positive effect on osteogenic differentiation. In line with this effect, 3-Dimesional (3D) scaffolds that can be used in bone tissue were produced by exploiting the properties of gold nanoparticles that increase biocompatibility and support bone tissue development. In addition, ampicillin was added to the scaffolds containing gold nanoparticles as a model drug to improve its antimicrobial properties. The scaffolds were produced as composites of polyvinyl alcohol (PVA) main matrix as PVA, PVA/AuNP, PVA/Ampicillin (AMP) and PVA/AuNP/AMP. Scanning Electron Microscopy (SEM) Fourier Transform Infrared Spectroscopy (FTIR), tensile measurement tests, and in vitro applications of 3D scaffolds were performed. As depicted by SEM, scaffolds were produced at pore sizes appropriate for bone tissue regeneration. According to FTIR results, there was no modification observed in the AMP, PVA and gold nanoparticles due to mixing in the resultant scaffolds. In vitro results show that 3D printed composite scaffold based on PVA/AuNP/AMP are biocompatible, osteo-inductive and exhibit antimicrobial properties, compared to PVA scaffolds. This study has implications for addressing infections during orthopedic surgeries. The PVA-based gold nanoparticle 3D tissue scaffold study containing ampicillin covers a new study compared to other articles based on gold nanoparticles.Article Citation - WoS: 7Citation - Scopus: 8Aptamer-Based Magnetic Isolation and Specific Detection System for listeria Monocytogenes from Food Samples(Elsevier, 2024) Bayramoglu, Gulay; Ozalp, Veli Cengiz; Arica, Mehmet YakupIn this work, an aptamer-based magnetic system was designed for specific and rapid detection of Listeria monocytogenes in food samples. To prepare the selective magnetic system against the target bacterium, firstly, magnetic particles (Fe3O4) were coated with two hydrophilic polymer layers. The specific aptamer immobilized magnetic system efficiently captured L. monocytogenes cells in a competitive response time of approximately 10 min. The magnetic aptamer detection system was very specific to L. monocytogenes and had high selective, up to 97.6 % compared to the Listeria species (Listeria ivanovii, Listeria innocua, and Listeria seeligeri) and other bacteria species Escherichia coli, Staphylococcus aureus, and Basillus subtilus. The isolation and detection of L. monocytogenes from food samples using the presented method are fast and reliable. Moreover, another significant factor to be contemplated is the use of a few chemicals for detection, reducing the cost of analysis, and the results can be obtained within 18 h.Article Citation - WoS: 1Citation - Scopus: 1Shallow Trapping Centers in Bi12geo20 Single Crystals by Thermally Stimulated Current Measurements(Elsevier, 2022) Delice, S.; Isik, M.; Gasanly, N. M.Bi12GeO20 single crystals were investigated by thermally stimulated current (TSC) experiments performed in the temperature range of 10-290 K. Recorded TSC glow curve exhibited six distinctive peaks with maxima at around 90, 105, 166, 209, 246, 275 K. The analyses of the obtained glow curve were accomplished by curve fitting and initial rise methods. The analysis results were in good agreement that the TSC peaks appeared in the glow curve due to existence of trapping levels with activation energies of 0.10, 0.18, 0.23, 0.53, 0.68 and 0.73 eV. These trapping levels were estimated to be hole traps above valence band. The heating rate dependent TSC glow curves were also obtained for various rates between 0.30 and 0.45 K/s. The changes of TSC intensity, peak maximum temperature and full-widths-half-maximum values with heating rates were studied in detail. TSC intensity decreased and peak maximum temperature increased with increasing heating rate. Determination of defects and trapping/stimulation mechanism of those are significant for technological applications since local states in these materials take critical role for device performance.Article Citation - WoS: 44Citation - Scopus: 54Towards a Circular Economy: Investigating the Critical Success Factors for a Blockchain-Based Solar Photovoltaic Energy Ecosystem in Turkey(Elsevier, 2021) Erol, Ismail; Peker, Iskender; Ar, Ilker Murat; Turan, Ismet; Searcy, CoryNovel business models can be implemented through digital platforms to enable better circular economy (CE) performance in the renewable energy industry. For example, blockchain can assist in developing innovative business models throughout the solar photovoltaic energy ecosystem (SPVEE) to improve CE. Ranked fifth in total installed photovoltaic (PV) capacity, Turkey, as a developing country, should take the necessary steps and make progress towards achieving CE in the SPVEE. The solar PV industry requires further innovation to address the negative environmental impact of existing linear business models. To ensure favorable results, identifying and evaluating critical success factors (CSFs) are necessary. However, no study has investigated CSFs for SPVEE or any other renewable energy source to achieve a blockchain-based infrastructure towards increased CE performance. Therefore, the goal of this study is to identify and examine the CSFs to improve the performance of a blockchain-based SPVEE towards CE in Turkey. To this end, first, the CSFs for blockchain-based SPVEE were identified through both a literature review and the Nominal Group Technique (NGT). Then, Intuitionistic Fuzzy (IF)DEMATEL was used to explore their interrelationships based on the expert data. Finally, IF-DELPHI was employed to validate the results. Our findings suggested that effective government incentive programs and regulations are significant for blockchain-based SPVEE towards CE in Turkey. The findings of this study assist macro and micro decision-making in the potential implementation of blockchain in Turkish SPVEE to improve CE. They are also invaluable for other countries and can be used as a reference point. (c) 2021 International Energy Initiative. Published by Elsevier Inc. All rights reserved.Article Citation - WoS: 27Citation - Scopus: 29Assessing Dependency of Part Properties on the Printing Location in Laser-Powder Bed Fusion Metal Additive Manufacturing(Elsevier, 2022) Mussatto, Andre; Groarke, Robert; Vijayaraghavan, Rajani K.; Hughes, Cian; Obeidi, Muhannad Ahmed; Dogu, Merve Nur; Brabazon, DermotDespite the accelerated growth of laser-powder bed fusion in recent years, there are still major obstacles to be overcome before the technology enjoys truly widespread adoption. These include inconsistent part quality and repeatability issues linked to variability in the properties of printed parts. Commonly, the print location across the build platform is overlooked and assumed to have little or no effect on the overall part properties. There is a lack of previous systematic studies and a lack of knowledge of the influences of the location parameter on the final part properties. Therefore, to address the existing problem, the current study completely isolated the location parameter to accurately assess any effect of this variable on the microstructure and mechanical properties of laser-powder bed fusion manufactured parts. The results revealed the importance of the build location and showed that there is correlation between the location parameter and part properties as qualitative and quantitative properties of printed parts varied between the selected extremity locations. The findings highlight the importance of considering the location of the part being printed on the build platform and how the location may need to be fixed for multiple builds in order to achieve acceptable repeatability.Article Citation - WoS: 5Citation - Scopus: 5Identification of Shallow Trap Centers in Inse Single Crystals and Investigation of Their Distribution: a Thermally Stimulated Current Spectroscopy(Elsevier, 2024) Isik, M.; Gasanly, N. M.Identification of trap centers in semiconductors takes great importance for improving the performance of electronic and optoelectronic devices. In the present study, we employed the thermally stimulated current (TSC) method within a temperature range of 10-280 K to explore trap centers in InSe crystal-a material with promising applications in next-generation devices. Our findings revealed the existence of two distinct hole trap centers within the InSe crystal lattice located at 0.06 and 0.14 eV. Through the leveraging the T-stop method, we offered trap distribution parameters of revealed centers. The results obtained from the experimental methodology employed to investigate the distribution of trap centers indicated that one of the peaks extended between 0.06 and 0.13 eV, while the other spanned from 0.14 to 0.31 eV. Notably, our research uncovers a remarkable variation in trap density, spanning one order of magnitude, for every 10 and 88 meV of energy variation. The results of our research present the characteristics of shallow trap centers in InSe, providing important information for the design and optimization of InSe-based optoelectronic devices.Review Citation - WoS: 4Citation - Scopus: 4Smart Hydrogels in Lab-On (loc) Applications(Elsevier, 2024) Tevlek, Atakan; Cretin, Esin AkbayLaboratory on-chip (LOC) technology facilitates numerous developments across diverse disciplines, such as medicine, tissue engineering, materials science, biomedical engineering, and biotechnology. Moreover, the potential applications appear boundless when LOC is integrated with intelligent hydrogels. In the literature, however, there are few accounts of the vast array of developments and applications that this combination has spawned. These new systems, which integrate smart hydrogels and LOC and thus significantly advance cuttingedge technology, have been thoroughly examined in this review. The functions of smart hydrogels in LOC applications were described and subsequently the developed intelligent hydrogels were classified as multiresponsive, thermo-responsive, pH-responsive, and stimuli-responsive (light, magnetic, and electric). Following this, details regarding tunable properties for LOC functions were provided, followed by a discussion of the fabrication processes and integration of these intelligent hydrogels into LOC systems, including their benefits and drawbacks. Following that, current literature examples of LOC systems utilizing these intelligent hydrogels for biosensing, 3D culture, tissue engineering, controlled release, personalized medicine, drug delivery, analyte enrichment, and organ-on-a-chip applications were presented. Following the presentation of state-of-the-art information regarding smart hydrogel characterization techniques, present challenges and prospective prospects were discussed.Editorial Citation - WoS: 47Citation - Scopus: 47Emergency Changes in International Guidelines on Treatment for Head and Neck Cancer Patients During the Covid-19 Pandemic(Elsevier, 2020) Chaves, Aline Lauda Freitas; Castro, Ana Ferreira; Marta, Gustavo Nader; Junior, Gilberto Castro; Ferris, Robert L.; Giglio, Raul Eduardo; Kowalski, Luiz Paulo[No Abstract Available]Article Citation - WoS: 30Citation - Scopus: 31Synthesis and Properties of 4,4-Difluoro (bodipy)-Based Conducting Copolymers(Elsevier, 2009) Cihaner, Atilla; Algi, FatihThe synthesis, characterization and engineering of a novel polymer based on a unique combination of 1,3,5,7-tetramethyl-8-(4-nitro-phenyl)-2,6-bis(2-thienyl)-4,4-difluoroboradiazaindacene and 3,4-ethylenedioxythiophene are highlighted. It was found that the polymer represents an environmentally robust electroactive material bearing high stability, well-defined quasi-reversible redox couple, and fast response time between redox states as well as high coloration efficiency. (c) 2008 Elsevier Ltd. All rights reserved.Article Citation - WoS: 2Citation - Scopus: 2Investigations of Ph-Dependent Dynamic Properties of Ompg-16sl, an Outer Membrane Protein G Mutant by Atr-Ftir Spectroscopy(Elsevier, 2022) Yilmaz, Irem; Korkmaz, FilizIn this paper, the dynamic properties of outer membrane protein G mutant (OmpG-16SL) are investigated with ATR-FTIR spectroscopy. While OmpG-WT has 14 beta-strands in its structure, the mutant is designed to have 16 beta-strands with the intention of creating an enlarged pore. Loop L6 is elongated by introducing six residues, two of which are negatively charged. The solvent accessibility of the OmpG-16SL mutant is compared with WT and a previously reported mutant OmpG-16S by tracking the H-1/H-2 exchange kinetics in acidic and neutral buffer conditions. The exchange kinetics and dynamics in the fast and slow exchange phases are separately investigated using the 2DCOS technique, which enables the tracking of the structural changes at each phase of the exchange process. The results suggest that the mutant OmpG-16SL is equally exposed to buffer in both acidic and neutral pH conditions. Additionally, the time range in the fast phase is very short - one-tenth of that for WT - and most of the exchange is completed in this phase. This fast exchange within minutes is also indicative of the presence of highly flexible and/or unstructured regions. In all, the fast exchange rates independent of the buffer pH justify the assumption that there is an altered interaction among the charged residues, which leads to a steadily-open pore. The role of the side-chain interactions within the pore and between the loops involving the loop L6 is also discussed.
