Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7148

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Now showing 1 - 10 of 11
  • Article
    Citation - WoS: 5
    Citation - Scopus: 7
    Targeting the Panoptosome Using Necrostatin-1 Reduces Panoptosis and Protects the Kidney Against Ischemia-Reperfusion Injury in a Rat Model of Controlled Experimental Nonheart-Beating Donor
    (Elsevier Science inc, 2024) Dokur, Mehmet; Uysal, Erdal; Kucukdurmaz, Faruk; Altinay, Serdar; Polat, Sait; Batcioglu, Kadir; Yeni, Sema Nur Dokur
    Purpose. Reducing renal ischemia is crucial for the function and survival of grafts from non- heartbeat donors, as it leads to inflammatory responses and tubulointerstitial damage. The primary concern with organs from nonheartbeat donors is the long warm ischemia period and reperfusion injury following renal transplantation. This study had two main goals; one goal is to determine how Necrostatin-1 targeting the PANoptosome affects PANoptosis in the nonheartbeating donor rat model. The other goal is to fi nd out if Necrostatin-1 can protect the kidney from ischemic injury for renal transplantation surgery. Methods. Twenty-four rats were grouped randomly as control and Necrostatin-1 in this experimental animal study, and we administered 1.65 mg/kg of Necrostatin-1 intraperitoneally to the experimental group for 30 minutes before cardiac arrest. We removed the rats' left kidneys and measured various oxidative stress marker measures such as malondialdehyde, superoxide dismutase, catalase, GPx, and 8-hydroxy-2-deoxyguanosine levels. We then subjected the tissues to immunohistochemical analysis, electron microscopy, and histopathological analysis. Findings. The Necrostatin-1 group had a lower total tubular injury score (P < .001) and less Caspase-3, gasdermin D, and mixed lineage kinase domain-like protein expression. Additionally, the apoptotic index of the study group was lower (P < .001). Furthermore, the study group had higher levels of superoxide dismutase and GPx (P < .05), whereas malondialdehyde levels were reduced (P = .009). Electron microscopy also revealed a significant improvement in tissue structure in the Necrostatin-1 group. Conclusion. Necrostatin-1 protects against ischemic acute kidney injury in nonheart-beating donor rats by inhibiting PANoptosis via the blockade of RIPK1. As a result of this, Necrostatin1 may offer novel opportunities for protecting donor kidneys from renal ischemia-reperfusion injury during transplantation in patients with end-stage kidney disease requiring a renal transplantation.
  • Article
    Citation - WoS: 1
    Citation - Scopus: 1
    Completeness of Energy Eigenfunctions for the Reflectionless Potential in Quantum Mechanics
    (Aip Publishing, 2024) Erman, Fatih; Turgut, O. Teoman
    There are a few exactly solvable potentials in quantum mechanics for which the completeness relation of the energy eigenstates can be explicitly verified. In this article, we give an elementary proof that the set of bound (discrete) states together with the scattering (continuum) states of the reflectionless potential form a complete set. We also review a direct and elegant derivation of the energy eigenstates with proper normalization by introducing an analog of the creation and annihilation operators of the harmonic oscillator problem. We further show that, in the case of a single bound state, the corresponding wave function can be found from the knowledge of continuum eigenstates of the system. Finally, completeness is shown by using the even/odd parity eigenstates of the Hamiltonian, which provides another explicit demonstration of a fundamental property of quantum mechanical Hamiltonians.
  • Conference Object
    Angular Momentum Loss by Magnetic Braking and Gravitational Radiation in Relativistic Binary Stars
    (Incoma Ltd, 2008) Yakut,K.; Kalomeni,B.; Tout,C.A.
    Angular momentum loss (AML) mechanisms and dynamical evolution owing to magnetic braking and gravitational radiation in relativistic binary stars (RBS) are studied with use of physical parameters collected from the literature. We have calculated and compared AML time scales for the RBS with non-degenerate components and double degenerate (DD) systems. © Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial- ShareAlike Licence.
  • Conference Object
    Citation - Scopus: 4
    Circular Economy in the Built Environment: a Systematic Literature Review on the Role of Digital Technologies Across Regional Contexts
    (Institute of Physics, 2024) Aral,D.; Kayaçetin,N.C.; Durmuş Arsan,Z.
    The built environment has a significant role in ecosystems and resource depletion. Therefore, its transition from linear into the circular economy (CE) is critical yet still progressing. While research on CE in the built environment (BE) is growing, an in-depth understanding of facilitators as digital technologies (DT) is required to accelerate its implementation. Investigating these digitalization efforts, considering the regional variations of developed and developing economies, needs to be deepened. This study aims to demonstrate state-of-the-art CE research, providing insight into how digital technology preferences evolved through regional context as a facilitator in the built environment. For this purpose, 80 articles were assessed by (i) descriptive and (ii) thematic analysis through a systematic literature review (SLR). The descriptive analysis highlights the trends in the literature on CE-enabling DT in the built environment. The thematic analysis indicates the prominent DT to facilitate the transition with a link to the regional context and related variations. The results identify integrated DT in CE studies and their relevance to the economic levels of several countries, and they show research gaps to guide future research. This study contributes to an emerging field of research at the nexus of the built environment, the circular economy, and digital technology by mapping regional research tendencies. © 2024 Institute of Physics Publishing. All rights reserved.
  • Conference Object
    Kinematic Design of a Novel Finger Exoskeleton Mechanism for Rehabilitation Exercises
    (Springer international Publishing Ag, 2024) Kiper, Gokhan; Inanc, Emirhan
    The paper presents the kinematic design of a novel low-cost two degree-of-freedom finger exoskeleton mechanism to be used for rehabilitation exercises for post-stroke or injured patients. The first degree-of freedom is for the flexion/extension of metacarpophalangeal joint and is achieved via a planar 4-bar loop. The second degree-of-freedom is for the simultaneous flexion/extension of distal/proximal interphalangeal joints and is achieved via an over-constrained double-spherical 6-bar linkage, where 3 of the links are the phalanges of the finger and 2 of the joints are finger joints themselves. So, the number of extra links are less compared to other designs in the literature. The motion of an index finger is recorded via image processing. The four-bar mechanism part is designed for optimum transmission angle characteristics. The formulation and application of the kinematic synthesis of the 6-bar linkage is presented. The design is verified via a prototype.
  • Article
    Citation - WoS: 1
    Citation - Scopus: 1
    Thickness-Dependent Characteristics and Oxidation of 2d-Cadmium
    (Royal Soc Chemistry, 2024) Gulucu, Arda; Sahin, Hasan
    In this study, the structural, electronic, and vibrational properties of the thinnest crystal structure that can be obtained by thinning bulk Cd down to a monolayer are investigated by performing first-principles calculations. Total energy optimization and dynamic stability calculations reveal that the single layer crystal structure has a hexagonal unitcell with a two-atomic basis where alternating layers are formed by trigonal arrangements of Cd atoms. Softening occurs with decreasing zone center optical phonon frequencies as a result of structural relaxation when going from a bulk to a single layer (SL) structure. It is also shown that the thinnest structure obtained from bulk Cd crystals maintains its metallic features despite the dimensional crossover. In addition, it is predicted through calculations that the SL Cd crystal strongly interacts with oxygen and that the oxidized regions even undergo chemical transformation to form a CdO crystal. In the double-layer CdO crystal resulting from the oxidation of individual Cd layers, the layers are connected to each other with partially covalent bonds, and this structure is a semiconductor with a band gap of 2.10 eV. On the one hand, the robust metallic structure of the thinnest possible Cd crystal provides flexibility for its use in nanoscale applications, on the other hand, the fact that its electronic properties can be changed by oxidation is important for optoelectronic device applications. In this study, the structural, electronic, and vibrational properties of the thinnest crystal structure that can be obtained by thinning bulk Cd down to a monolayer are investigated by performing first-principles calculations.
  • Conference Object
    Citation - Scopus: 1
    Experimental and Numerical Investigation of Energy Absorption Characteristics of a E-glass/Epoxy Crash Box
    (Institute of Physics, 2024) Bilmez,S.A.; Taşdemirci,A.
    Crash boxes are energy absorbing components generally placed at the front end of cars to reduce the amount of damage at especially low impact velocities. The number of electric vehicles has been increasing recently, so weight reduction studies are. For this reason, lighter glass or carbon fiber reinforced composite crash boxes are preferred instead of steel ones. In the current study, the dynamic compression behavior of a rectangular cross-section thin-walled composite crash box was investigated both experimentally and numerically. The main aim of the study was to understand the effective damage modes and monitor the deformation sequence experimentally and numerically. Once the numerical model is verified then it can be further used to reveal the behavior at different impact velocities and geometries. The methodology followed in the study first started with the static mechanical characterization of the composite material. Within the scope of this study, 2x2 twill-woven glass fiber/epoxy crash boxes were produced using the vacuum bagging method. Quasi-static compression and tension tests were carried out in accordance with ASTM D3039 and ASTM D6641 standards. In the numerical part, Radioss finite element package was used with the material model of MAT 25 along with the failure option of Tsai-Wu. Experimental dynamic crushing tests of the crash box was carried out using a custom made drop-weight tester at impact velocity of 4.4 m/s and dropping mass with 450 kg. The material model constants were obtained once the coupon based static and dynamic tests were completed. From the dynamic crushing tests, maximum and mean force values of 225 and 65.0 kN were noted, respectively. There is close agreement between the experimental and numerical results both in terms of force and displacement values. This verified numerical model can further be used to investigate the crushing characteristics at different impact conditions. © 2024 Institute of Physics Publishing. All rights reserved.
  • Article
    Citation - WoS: 6
    Citation - Scopus: 6
    Evaluation of the Extracts of Purple Basil (<i>ocimum Basilicum</I> L.) as Natural Ph-Indicator Dyes Anticipated To Be Utilised in Intelligent Food Packaging-An Optimisation Study
    (Wiley, 2024) Erez, Elif; Bayramoğlu, Beste; Bayramoglu, Beste
    Purple basil (Ocimum basilicum L.) extract has significant potential as a natural colorimetric pH-indicator material owing to its abundance in anthocyanins. This contribution is the first to optimise the ultrasound-assisted extraction of purple basil by response surface methodology in terms of maximum total monomeric anthocyanin (TMA) content and pH-dependent increase in green intensity (IGI) using a three-level, three-factor Box-Behnken design. The latter was considered as a measure of the pH-indicator ability of the extracts. The independent variables were ethanol concentration, solvent/solid ratio, and extraction time for two types of solvents [aqueous ethanol with 0.1% (v/v) acetic acid (Ac) or hydrochloric acid]. Optimum conditions were determined for single and combined responses. The extracts were further characterised according to total phenolic content (TPC), percentage polymeric colour (PPC), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) antioxidant, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities. All models explained more than 93% of the variability. The combined response model for the Ac-acidified system gave more favourable optimal conditions [55.25% (v/v) ethanol, 30 mL/g solvent/solid ratio and 39.24 min] regarding lower ethanol consumption and shorter times. Validation experiments verified the model successfully predicted the responses. The corresponding TMA, IGI, PPC, TPC, ABTS, and DPPH values were determined as 4.83 +/- 0.18 mg cyanidin-3-glucoside equivalent, 2.29 +/- 0.05, 68.07 +/- 3.17, 28.79 +/- 1.54 mg gallic acid equivalent, 55.85 +/- 1.71 mg Trolox equivalent, and 16.80 +/- 1.08 mg ascorbic acid equivalent per gram dry weight, respectively.
  • Article
    Citation - WoS: 1
    Citation - Scopus: 1
    Effect of Urbanization on Groundwater Resources Hydrodynamics and Bearing Capacity: a Case Study From the Bayraklı Region, Izmir, ̇ Türkiye
    (Geological Society of London, 2024) Öztürk,B.; İşbuğa,V.; Bilgiç,E.; Baba,A.
    The bearing capacity of soil is a critical factor in the design of foundations for civil engineering structures. The bearing capacity depends on soil properties, as well as the location of the water table. A rise in the groundwater level can be dramatic, especially in highly urbanized regions, and can affect the bearing capacity of foundations. In this study, groundwaterlevel fluctuations in a highly urbanized region in Izmir, the third largest city in Türkiye, was monitored over a 1 year period, and ̇ its effect on reducing the bearing capacity, which is not considered in foundation design and construction, was investigated. For this purpose, four observation wells equipped with groundwater data loggers were used to determine the variations in groundwater level over 1 year. Using the Terzaghi approach to calculate the bearing capacity, normalized bearing capacity plots for various foundation width/depth (B/Df) ratios were generated for all four observation wells. Remarkable bearing capacity changes of 10.94, 8.21, 7.62 and 9.29% were observed in four different observation wells (OW-1, OW-3, OW-6 and OW-9, respectively). The study showed that changes in groundwater level in the region caused by urbanization poses a potential risk to the sustainability of previously constructed foundations. © 2024 The Author(s).
  • Conference Object
    Citation - Scopus: 2
    Machine-Learning Assisted Insights Into Cytotoxicity of Zinc Oxide Nanoparticles
    (Institute of Physics, 2024) Bilgi,E.; Karakus,C.O.
    Zinc oxide nanoparticles (ZnO NPs) are commercially used as an active ingredient or a color additive in foods, pharmaceuticals, sun protection lotions, and cosmetic products. While the use of ZnO NPs in everyday products has not been linked to any serious health issues so far, the scientific evidence generated for their safety is not conclusive and, in most cases, could not be validated further in in vivo settings. To settle controversies arising from inconsistent in vitro findings in previous research focusing on the toxicity ZnO NPs, we combined the results of 25+ independent studies. One way analysis of variance (ANOVA) and classification and regression tree (CART) algorithm were used to pinpoint intrinsic and extrinsic factors influencing cytotoxic potential of ZnO in nanoscale. Particle size was found to have the most significant impact on the cytotoxic potential of ZnO NPs, with 10 nm identified as a critical diameter below which cytotoxic effects were elevated. As expected, strong cell type-, exposure duration- and dose-dependency were observed in cytotoxic response of ZnO NPs, highlighting the importance of assay optimization for each cytotoxicity screening. Our findings also suggested that ≥12 hours exposure to NPs resulted in cytotoxic responses irrespective of the concentration. Considering the cumulative nature of research processes where advances are made through subsequent investigations over time, such meta-analytical approaches are critical to maximizing the use of accumulated data in nano-safety research. © 2024 Institute of Physics Publishing. All rights reserved.