Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
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Correction Chlorinated Phosphorene for Energy Application (vol 231, 112625, 2024)(Elsevier, 2024) Hassani, Nasim; Yagmurcukardes, Mehmet; Peeters, Francois M.; Neek-Amal, Mehdi[No Abstract Available]Article Citation - WoS: 1Citation - Scopus: 1Real-Time Superficial Vein Imaging System for Observing Abnormalities on Vascular Structures(Springer, 2024) Altay, A.; Gumus, A.Circulatory system abnormalities might be an indicator of diseases or tissue damage. Early detection of vascular abnormalities might have an important role during treatment and also raise the patient’s awareness. Current detection methods for vascular imaging are high-cost, invasive, and mostly radiation-based. In this study, a low-cost and portable microcomputer-based tool has been developed as a Near-Infrared (NIR) superficial vascular imaging device. The device uses NIR Light-Emitting Diode (LED) light at 850 nm along with other electronic and optical components. It operates as a non-contact and safe infrared (IR) imaging method in real-time. Image and video analysis are carried out using OpenCV (Open-Source Computer Vision), a library of programming functions mainly used in computer vision. Various tests were carried out to optimize the imaging system and set up a suitable external environment. To test the performance of the device, the images taken from three diabetic volunteers, who are expected to have abnormalities in the vascular structure due to the possibility of deformation caused by high glucose levels in the blood, were compared with the images taken from two non-diabetic volunteers. As a result, tortuosity was observed successfully in the superficial vascular structures, where the results need to be interpreted by the medical experts in the field to understand the underlying reasons. Although this study is an engineering study and does not have an intention to diagnose any diseases, the developed system here might assist healthcare personnel in early diagnosis and treatment follow-up for vascular structures and may enable further opportunities. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2023.Conference Paper Citation - Scopus: 1Effect of Tsunami Induced Currents on Floating Pontoons With the Mooring Lines(American Society of Civil Engineers (ASCE), 2023) Ozbahceci, B.O.; Celik, H.; Girgin, E.; Yalciner, A.C.; Dogan, G.G.[No abstract available]Article Citation - WoS: 3Citation - Scopus: 3Liquid Metal-Tunable Miniaturized Bimodal Cavity for Enhanced Measurement Accuracy in the Ism Bands(Ieee-inst Electrical Electronics Engineers inc, 2024) Karatay, Anil; Yaman, FatihEnhancing measurement accuracy or reducing the effect of the neighboring modes in resonant cavities may necessitate the separation of mode frequencies. However, in ISM-band measurement configurations utilizing a rectangular or cylindrical cavity, the placement of the first two modes at 2.45 and 5.8 GHz is unattainable, necessitating the presence of additional modes in between that would potentially degrade measurement accuracy. This article begins with an analytical approach, employing Lagrange multipliers for the first time to reveal the level of separation achievable in the frequency domain between the initial two modes within these types of conventional cavities. The analytical results were also verified with a numerical grid search. Subsequently, innovative strategies have been introduced to surpass this intrinsic constraint that reduces the measurement accuracy in various applications. A novel miniaturized cavity configuration has been proposed to operate bimodally at 2.45 and 5.8 GHz and manufactured with a 3-D printer. It has been ensured that there are no physical modes present in between, and measurements of the structure have been conducted. Another notable innovation of the article is the capability of tuning the proposed cavity structure by means of liquid metal displacement. Thus, a more flexible tuning method compared to mechanical tuning techniques can be achieved, enabling precise adjustment of the desired measurement frequency. Good agreement between the simulation and measurement results has been reported.Conference Paper Magnetic Levitation-Based Endothelial Cell Sorting(Institute of Electrical and Electronics Engineers Inc., 2023) Ozcan, H.A.; Kecili, S.; Tekin, H.C.Cell sorting for rare cells is crucial for diagnostic purposes. Circulating Endothelial Cells (CECs) can be used as cardiovascular disease markers. Due to the rareness of the CECs in the blood, an accurate, easy, cost and time-effective sorting method is a need. Magnetic levitation is a promising technique for observing differences in the average height of endothelial and white blood cells which does not require any labeling. This study aims to show that the magnetic levitation principle can be used for sorting endothelial cells from the blood. By using paramagnetic medium concentrations of 10 mM and 50 mM, the average levitation height between HUVECs used as a model endothelial cells and U937 cells used as model of white blood cells was measured as 65 μm and 32 μm, respectively. Since there is a significant difference in levitation height for HUVECs and U937 cells, magnetic levitation technology exhibits promising potential for the precise sorting of endothelial cells. © 2023 IEEE.Article Citation - WoS: 3Citation - Scopus: 3Light-Induced Synthesis of Single-Crystalline Gold Microplates in an Open System(Amer Chemical Soc, 2023) Akkuş, Betül; Mert Balcı, FadimeBottom-up synthesis of large single-crystalline gold microplates is of key importance to catalysis, nanophotonics, bioengineering, and plasmonics. However, easy, low-cost, room-temperature, and high-yield synthesis of large gold microplates with several micrometers in lateral size and a few tens of nanometers in thickness by using photochemical synthesis in an open system is still challenging. We herein report on an easy and cost-effective photochemical synthesis of single-crystalline gold microplates with lateral sizes up to around 40 mu m and tens of nanometers in thickness in a few hours of reaction time in an open system containing a lyotropic liquid crystal, which is formed by self-assembly of 10-lauryl ether in a strong acid, sulfuric acid, along with water. We have found that by changing the reaction parameters, such as the reaction time, the concentration of gold ions in the liquid crystal, etc., the thickness and size of the microplates can be easily controlled. Most importantly, the liquid crystalline phase is completely preserved after completion of the photochemical reaction. The microplates can be easily isolated and transferred to different media such as alcohol and water for further studies, or they can be immediately used on a substrate after completion of the reaction. The results obtained in this study will allow us to understand the growth mechanism of gold microplates in open systems, and they will find applications in a variety of critical areas, such as plasmonics, nanophotonics, and catalysis.Conference Object Serum Creatinine Detection in a Microfluidic Chip Using a Smartphone Camera(Chemical and Biological Microsystems Society, 2022) Karakuzu, B.; Tarim, E.A.; Tekin, H.C.We present a microfluidic chip platform to detect serum creatinine levels using the enzyme-linked immunosorbent assay (ELISA) principle. In the platform, surface modified microfluidic channel sensitively captured target molecules from the serum sample, and then ELISA protocol was applied inside the channels. Afterward, the blue color formed as a result of the enzymatic reaction was measured via a smartphone camera. The proposed strategy allows the detection of creatinine rapidly in a minute amount of the serum samples without the need for expensive equipment. Thus, chronic kidney disease (CKD) could be monitored easily at point-of-care settings via the proposed creatinine detection strategy. © 2022 MicroTAS 2022 - 26th International Conference on Miniaturized Systems for Chemistry and Life Sciences. All rights reserved.Conference Object Magnetic Levitation-Based Viscosity Measurement in a Microcappilary Channel(Chemical and Biological Microsystems Society, 2022) Doyran, O.; Tekin, H.C.Viscosity, has been known as the key rheological parameter, to characterize biological, chemical and physical material properties. In this work, we have developed a magnetic levitation-based viscosity measurement method in a microcapillary channel. For this purpose, polymer microspheres are utilized as microsensors to correlate solution viscosity to microspheres' velocity while microspheres are balanced at a stable levitation position. This inexpensive and practical system enables rapid viscosity measurement from low amount of sample. © 2022 MicroTAS 2022 - 26th International Conference on Miniaturized Systems for Chemistry and Life Sciences. All rights reserved.Conference Object Quote Detection: a New Task and Dataset for Nlp(Association for Computational Linguistics, 2023) Tekir, S.; Güzel, A.; Tenekeci, S.; Haman, B.U.Quotes are universally appealing. Humans recognize good quotes and save them for later reference. However, it may pose a challenge for machines. In this work, we build a new corpus of quotes and propose a new task, quote detection, as a type of span detection. We retrieve the quote set from Goodreads and collect the spans through a custom search on the Gutenberg Book Corpus. We run two types of baselines for quote detection: Conditional random field (CRF) and summarization with pointer-generator networks and Bidirectional and Auto-Regressive Transformers (BART). The results show that the neural sequence-to-sequence models perform substantially better than CRF. From the viewpoint of neural extractive summarization, quote detection seems easier than news summarization. Moreover, model fine-tuning on our corpus and the Cornell Movie-Quotes Corpus introduces incremental performance boosts. Finally, we provide a qualitative analysis to gain insight into the performance. © 2023 Association for Computational Linguistics.Article Citation - Scopus: 6Functional Characterization of a Novel Cyp119 Variant To Explore Its Biocatalytic Potential(John Wiley and Sons Inc, 2022) Sakalli, T.; Surmeli, N.B.Biocatalysts are increasingly applied in the pharmaceutical and chemical industry. Cytochrome P450 enzymes (P450s) are valuable biocatalysts due to their ability to hydroxylate unactivated carbon atoms using molecular oxygen. P450s catalyze reactions using nicotinamide adenine dinucleotide phosphate (NAD(P)H) cofactor and electron transfer proteins. Alternatively, P450s can utilize hydrogen peroxide (H2O2) as an oxidant, but this pathway is inefficient. P450s that show higher efficiency with peroxides are sought after in industrial applications. P450s from thermophilic organisms have more potential applications as they are stable toward high temperature, high and low pH, and organic solvents. CYP119 is an acidothermophilic P450 from Sulfolobus acidocaldarius. In our previous study, a novel T213R/T214I (double mutant [DM]) variant of CYP119 was obtained by screening a mutant library for higher peroxidation activity utilizing H2O2. Here, we characterized the substrate scope; stability toward peroxides; and temperature and organic solvent tolerance of DM CYP119 to identify its potential as an industrial biocatalyst. DM CYP119 displayed higher stability than wild-type (WT) CYP119 toward organic peroxides. It shows higher peroxidation activity for non-natural substrates and higher affinity for progesterone and other bioactive potential substrates compared to WT CYP119. DM CYP119 emerges as a new biocatalyst with a wide range of potential applications in the pharmaceutical and chemical industry. © 2021 International Union of Biochemistry and Molecular Biology, Inc.