PubMed İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/397
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Article Radar Resolution Enhancement Based on Burg-Aided MIMO-DBS and Burg-Aided MIMO-SAR †(MDPI, 2026) Bekar, Muge; Bekar, Ali; Baker, Christopher John; Gashinova, Marina; Pirkani, AnumAutonomous systems require sensors that provide high-resolution imagery in adverse lighting and weather conditions for advanced situational awareness. In this regard, radars are a mandatory component of autonomous systems. Although Multiple-Input Multiple-Output (MIMO) radars provide high angular resolution beyond that of their actual physical dimension, much higher cross-range resolutions are required, especially in traffic congested areas, to differentiate and recognize closely positioned targets. The motion of the MIMO radar platform can be exploited to obtain higher cross-range resolution in the off-boresight direction, using Synthetic Aperture Radar (SAR) and Doppler Beam Sharpening (DBS) techniques, but improvements in the boresight direction, the most crucial direction for path planning, require the use of super-resolution techniques. This paper proposes a technique that combines the Burg algorithm with MIMO-SAR and MIMO-DBS radar data to enhance the cross-range resolution in the boresight direction and to achieve further enhanced cross-range resolution in off-boresight directions. The proposed technique is applied to both frequency domain and time domain data in back-projection (BP) and DBS image formation processing. A comprehensive comparison is made, with evaluation of corresponding performance and operational complexity. The performance of the technique is validated through simulation, lab-based and real-world experiments at a frequency of 77 GHz.Article Performance Evaluation of Multi-Modal Radar Signal Processing in Dense Co-Existent Environments(MDPI, 2026) Norouzian, Fatemeh; Bekar, Muge; Bekar, Ali; Gashinova, Marina; Pirkani, AnumThe wide-scale deployment of radars, distributed across a platform and across multiple platforms for reliable 360 degrees situational awareness (SA), introduces the challenge of radar interference. Interference can broadly be categorised as self-interference (between radars mounted on the same platform) and mutual interference (signals received from radars on other platforms). Both types of interference impede the reliability of SA delivered by such systems, particularly in dense environments where numerous radars operate simultaneously within the same frequency band. This work presents a comprehensive evaluation of a multi-modal beamforming approach that combines unfocused synthetic aperture radar with the traditional Multiple-Input, Multiple-Output beamformer to enhance radar resolution and suppress interference. Additionally, various aspects of sensor configurations defining hardware and software capabilities of state-of-the-art radars are discussed, and a systematic analysis of signal-to-interference-plus-noise ratio at each step of the processing is presented. Extensive simulations and experimental results in both automotive and maritime environments are shown to validate the effectiveness of the proposed approach.Article CRISPR/Cas9-mediated Metabolic Engineering of Endophytic Pseudomonas Loganensis Sp. Nov. for the Production of Nutritionally Valuable Carotenoids(American Chemical Society, 2026-01-02) Arslansoy, N.; Karaman, M.Z.; Fidan, O.Carotenoids with significant nutritional and antioxidant properties have been widely utilized in the food, feed, pharmaceutical, and cosmetic industries. They improve the nutritional value of foodstuffs and have been used as natural food colorants. However, their current supply chain is mainly dependent on extraction from plants and chemical synthesis, both of which have bottlenecks, including environmental concerns, toxicity, and allergenicity. To address global demand for sustainable and environmentally friendly production of nutrients, we engineered the endophytic Pseudomonas loganensis sp. nov. as a niche microbial chassis for nutritionally valuable carotenoid production. Using CRISPR-Cas9, we knocked out key carotenogenic genes to construct strains capable of producing zeaxanthin, lycopene, and β-carotene. Additionally, an overexpression plasmid was introduced to produce astaxanthin. HPLC analysis confirmed the successful production of four target carotenoids. The culture conditions and media compositions were optimized using response surface methodology, resulting in a ∼5-fold increase in the titers of zeaxanthin (13.4 mg/L), lycopene (9.67 mg/L), and β-carotene (23.53 mg/L), and a ∼12-fold increase in astaxanthin titer (1 mg/L) compared to LB medium without optimization. Our results indicate the potential of endophytic bacteria as a microbial chassis for carotenoid bioproduction, underscoring the potential of synthetic biology to contribute to global efforts toward nutritional security and sustainable food systems. © 2026 The Authors. Published by American Chemical SocietyArticle Does Your Love Lift Me Higher? A Direct Replication of the Energising Role of Secure Relationships(John Wiley & Sons Ltd, 2025-12-07) Lagap, Adar Cem; Harma, MehmetPrevious work has revealed that priming people with significant others increases feelings of security and energy, and in turn, boosts exploration motivations. In this preregistered study, we directly replicated Luke et al.'s (2012) Study 2 (N = 281). We found similar results as the replicated study regarding increased security feelings and exploration motivations on the self-report measures after the priming. However, we did not find any support for the increased energy feelings after the attachment security priming. In addition, contrary to Luke et al.'s (2012) results, energy feelings did not mediate the relationship between security priming and exploration motivations. A discussion of null findings, along with the limitations of self-reports and potential misinterpretation of the mediational analyses, follows. We also discuss possible future implications of the current findings.Article Citation - WoS: 1Citation - Scopus: 1Burg-Aided 2D MIMO Array Extrapolation for Improved Spatial Resolution(MDPI, 2025-10-12) Bekar, Muge; Bekar, Ali; Pirkani, Anum; Baker, Christopher John; Gashinova, MarinaIn this paper, the extrapolation of a 2D multiple-input multiple-output (MIMO) array is proposed using the Burg algorithm to achieve higher angular resolution beyond that of the corresponding 2D MIMO virtual array. The main advantage of such an approach is that it allows us to dramatically decrease both the physical size and the number of antenna elements of the MIMO array. The performance and limitations of the Burg algorithm are examined through both simulation and experimentation at 77 GHz. The experimental methodology used to acquire 3D data of range, azimuth and elevation information with the 1D MIMO off-the-shelf radar is described. Using this method, the performance of the proposed array can be tested experimentally, especially at frequencies where it is desired to assess the antenna response prior to fabricating the antenna.Article Citation - WoS: 24Citation - Scopus: 26Wireless Measurement of Elastic and Plastic Deformation by a Metamaterial-Based Sensor(MDPI, 2014-10-20) Ozbey, Burak; Demir, Hilmi Volkan; Kurc, Ozgur; Erturk, Vakur B.; Altintas, AyhanWe report remote strain and displacement measurement during elastic and plastic deformation using a metamaterial-based wireless and passive sensor. The sensor is made of a comb-like nested split ring resonator (NSRR) probe operating in the near-field of an antenna, which functions as both the transmitter and the receiver. The NSRR probe is fixed on a standard steel reinforcing bar (rebar), and its frequency response is monitored telemetrically by a network analyzer connected to the antenna across the whole stress-strain curve. This wireless measurement includes both the elastic and plastic region deformation together for the first time, where wired technologies, like strain gauges, typically fail to capture. The experiments are further repeated in the presence of a concrete block between the antenna and the probe, and it is shown that the sensing system is capable of functioning through the concrete. The comparison of the wireless sensor measurement with those undertaken using strain gauges and extensometers reveals that the sensor is able to measure both the average strain and the relative displacement on the rebar as a result of the applied force in a considerably accurate way. The performance of the sensor is tested for different types of misalignments that can possibly occur due to the acting force. These results indicate that the metamaterial-based sensor holds great promise for its accurate, robust and wireless measurement of the elastic and plastic deformation of a rebar, providing beneficial information for remote structural health monitoring and post-earthquake damage assessment.Article Citation - WoS: 15Citation - Scopus: 14Tuning the Shades of Red Emission in InP/ZnSe Nanocrystals With Narrow Full Width for Fabrication of Light-Emitting Diodes(Amer Chemical Soc, 2023-10-13) Soheyli, Ehsan; Bicer, Aysenur; Ozel, Sultan Suleyman; Tiras, Kevser Sahin; Mutlugun, Evren; Sahin Tiras, KevserWhile Cd-based luminescent nanocrystals (NCs) are the most mature NCs for fabricating efficient red light-emitting diodes (LEDs), their toxicity related limitation is inevitable, making it necessary to find a promising alternative. From this point of view, multishell-coated, red-emissive InP-based NCs are excellent luminescent nanomaterials for use as an emissive layer in electroluminescent (EL) devices. However, due to the presence of oxidation states, they suffer from a wide emission spectrum, which limits their performance. This study uses tris-(dimethyl-amino)-phosphine (3DMA-P) as a low-cost aminophosphine precursor and a double HF treatment to suggest an upscaled, cost-effective, and one-pot hot-injection synthesis of purely red-emissive InP-based NCs. The InP core structures were coated with thick layers of ZnSe and ZnS shells to prevent charge delocalization and to create a narrow size distribution. The purified NCs showed an intense emission signal as narrow as 43 nm across the entire red wavelength range (626-670 nm) with an emission quantum efficiency of 74% at 632 nm. The purified samples also showed an emission quantum efficiency of 60% for far-red wavelengths of 670 nm with a narrow full width of 50 nm. The samples showed a relatively long average emission lifetime of 50-70 ns with a biexponential decay profile. To demonstrate the practical ability of the prepared NCs in optoelectronics, we fabricated a red-emissive InP-based LEDs. The best-performing device showed an external quantum efficiency (EQE) of 1.16%, a luminance of 1039 cd m(-2), and a current efficiency of 0.88 cd A(-1).Article Citation - WoS: 35Citation - Scopus: 35Therapeutic Targeting of FLT3 in Acute Myeloid Leukemia: Current Status and Novel Approaches(Dove Medical Press Ltd, 2022-11) Tecik, Melisa; Adan, AysunFMS-like tyrosine kinase 3 (FLT3) is mutated in approximately 30% of acute myeloid leukemia (AML) patients. The presence of FLT3-ITD (internal tandem duplication, 20-25%) mutation and, to a lesser extent, FLT3-TKD (tyrosine kinase domain, 5- 10%) mutation is associated with poorer diagnosis and therapy response since the leukemic cells become hyperproliferative and resistant to apoptosis after continuous activation of FLT3 signaling. Targeting FLT3 has been the focus of many pre-clinical and clinical studies. Hence, many small-molecule FLT3 inhibitors (FLT3is) have been developed, some of which are approved such as midostaurin and gilteritinib to be used in different clinical settings, either in combination with chemotherapy or alone. However, many questions regarding the best treatment strategy remain to be answered. On the other hand, various FLT3-dependent and -independent resistance mechanisms could be evolved during FLT3i therapy which limit their clinical impact. Therefore, identifying molecular mechanisms of resistance and developing novel strategies to overcome this obstacle is a current interest in the field. In this review, recent studies of approved FLT3i and knowledge about major resistance mechanisms of clinically approved FLT3i's will be discussed together with novel treatment approaches such as designing novel FLT3i and dual FLT3i and combination strategies including approved FLT3i plus small-molecule agents targeting altered molecules in the resistant cells to abrogate resistance. Moreover, how to choose an appropriate FLT3i for the patients will be summarized based on what is currently known from available clinical data. In addition, strategies beyond FLT3i's including immunotherapeutics, small-molecule FLT3 degraders, and flavonoids will be summarized to highlight potential alternatives in FLT3-mutated AML therapy.Article Citation - WoS: 35Citation - Scopus: 44The Role of Frictional Contact of Constituent Blocks on the Stability of Masonry Domes(Royal Soc, 2018-01) Beatini, Valentina; Royer-Carfagni, Gianni; Tasora, AlessandroThe observation of old construction works confirms that masonry domes can withstand tensile hoop stresses, at least up to a certain level. Here, such tensile resistance, rather than a priori assumed as a property of the bulk material, is attributed to the contact forces that are developed at the interfaces between interlocked blocks under normal pressure, specified by Coulomb's friction law. According to this rationale, the aspect ratio of the blocks, as well as the bond pattern, becomes of fundamental importance. To investigate the complex assembly of blocks, supposed rigid, we present a non-smooth contact dynamic analysis, implemented in a custom software based on the Project Chrono C++ framework and complemented with parametric-design interfaces for pre- and post-processing complex geometries. Through this advanced tool, we investigate the role of frictional forces resisting hoop stresses in the stability of domes, either circular or oval, under static and dynamic loading, focusing, in particular, on the structural role played by the underlying drumand the surmounting tiburium.Article The Need for Death Pedagogy: Academics' Opinions on the Place of Death in the Curricula(Routledge Journals, Taylor & Francis Ltd, 2025-06-02) Sonbul, Zeynep FundaThis paper seeks to explore the opinions of educational sciences academics on how death pedagogy should be integrated into curricula across preschool, primary, secondary, and high school levels. The sample comprises academics specializing in educational sciences, who have conducted at least two studies on death, loss, and bereavement, and are affiliated with various universities in T & uuml;rkiye. Seven academics responded to six open-ended questions, and their qualitative responses were analyzed. The results indicated unanimous support for including death pedagogy in the formal curriculum. Key implementation considerations include: (a) collaborating with experts to define the content, methods, and scope; (b) providing comprehensive training for all teachers on the subject and offering additional support for those grappling with their own mortality; (c) ensuring that school counselors play a central role in all phases of planning, implementation, and evaluation; and (d) highlighting the significance of death pedagogy in fostering students' psychological resilience.