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Article Citation - WoS: 5Citation - Scopus: 5The Effect of Zn Concentration on the Structural and Optical Properties of Cd1-xznx< Nanostructured Thin Films(Springer, 2021) Isik, M.; Terlemezoglu, M.; Isik, S.; Erturk, K.; Gasanly, N. M.The structural and optical properties of electrodeposited Cd1-xZnxS nanostructured thin films were investigated in the present paper for compositions of x = 0, 0.03, 0.06 and 0.09. X-ray diffraction patterns of the deposited thin films consisted of diffraction peaks related to cubic crystal lattice. The atomic compositional ratios were determined by performing energy dispersive spectroscopy measurements. Scanning electron microscopy images indicated that deposited thin films have nanostructured forms. Raman spectra of the Cd1-xZnxS thin films exhibited two vibrational modes associated with longitudinal optical mode and its first overtone. Transmission measurements were performed on the deposited thin films to get their band gap energies. It was seen from the analyses of absorption coefficient that band gap energy of Cd1-xZnxS thin films increases almost linearly from 2.40 to 2.51 eV as the composition was increased from x = 0 to x = 0.09.Article Citation - WoS: 3Citation - Scopus: 3Detection of spermatogonial stem/progenitor cells in prepubertal mouse testis with deep learning(Springer/plenum Publishers, 2023) Kahveci, Burak; Onen, Selin; Akal, Fuat; Korkusuz, PetekPurposeRapid and easy detection of spermatogonial stem/progenitor cells (SSPCs) is crucial for clinicians dealing with male infertility caused by prepubertal testicular damage. Deep learning (DL) methods may offer visual tools for tracking SSPCs on testicular strips of prepubertal animal models. The purpose of this study is to detect and count the seminiferous tubules and SSPCs in newborn mouse testis sections using a DL method.MethodsTesticular sections of the C57BL/6-type newborn mice were obtained and enumerated. Odd-numbered sections were stained with hematoxylin and eosin (H&E), and even-numbered sections were immune labeled (IL) with SSPC specific marker, SALL4. Seminiferous tubule and SSPC datasets were created using odd-numbered sections. SALL4-labeled sections were used as positive control. The YOLO object detection model based on DL was used to detect seminiferous tubules and stem cells.ResultsTest scores of the DL model in seminiferous tubules were obtained as 0.98 mAP, 0.93 precision, 0.96 recall, and 0.94 f1-score. The SSPC test scores were obtained as 0.88 mAP, 0.80 precision, 0.93 recall, and 0.82 f1-score.ConclusionSeminiferous tubules and SSPCs on prepubertal testicles were detected with a high sensitivity by preventing human-induced errors. Thus, the first step was taken for a system that automates the detection and counting process of these cells in the infertility clinic.Article Citation - Scopus: 3Evaluating Effectiveness of Led and Oled Lights on User Visual Comfort and Reading Performance(Istanbul Teknik Universitesi, Faculty of Architecture, 2021) Avci,A.N.; Memikoğlu,İ.In interior architecture, one of the main purposes of light is to create comfortable and functional spaces according to user needs. Light provides individuals to understand, get information for visual tasks and it affects how they experience and behave in the environment. Desired illuminance levels are required for visual comfort and task efficiency. This study analyzes the effects of different illuminance levels of light emitting diode (LED) and organic light emitting diodie (OLED) lights on user visual comfort and reading performance. An experiment was con-ducted with eighty interior architecture students at Çankaya University. Six lighting scenarios were created with LED and OLED lighting sources that assessed six visual comfort criteria. The experimental setting consisted of three different illuminance levels, as 200, 500 and 800 lx. The results revealed that different illuminance levels were found more comfortable for different visual comfort criteria, but the illuminance level of 500 lx was visually more comfortable than the other illuminance levels. The illuminance level of LED 200 lx was visually more comfortable than LED 800 lx. OLED light was found visually more comfortable than LED light. In addition, participants read slower under the illuminance level of LED 200 lx. It was concluded that illuminance levels of light effect user’s visual comfort and reading performance. This study provides a basis to recommend the preferred illuminance level for LED and OLED light during a reading performance. © 2021, Istanbul Teknik Universitesi, Faculty of Architecture. All rights reserved.Article The Relationship Between Operational Efficiency and Financial Efficiency in the Shipping Industry: An Example From Privatized Ports in Türkiye(EDP Sciences S A, 2025) Kaya, Ebru Nur; Mete, Mevlut Hurol; Belgin, OnderSince the ports are the backbone of international trade they need to be managed efficiently. This study addresses to analyze the operational and financial efficiency of the selected privatized ports that have been belonged to TCDD (Republic of T & uuml;rkiye State Railways). For this purpose, EATWOS (Efficiency Analysis Technique with Output Satisfying) method is employed, and the weights of the inputs and outputs are determined using LOPCOW (Logarithmic Percentage Change-Driven Objective Weighting), MEREC (Method Based on the Removal Effects of Criteria), and CRITIC (Criteria Importance Through Intercriteria Correlation) methods. After obtaining the weights from these objective methods, the comprehensive weights are calculated using TPOP (Technique of Precise Order Preference) method. Finally, Spearman's rank-order correlation shows that there is no relationship between the operational and financial efficiency of the ports. The number of studies that address both operational and financial efficiency of ports is limited, and this study distinguishes itself by investigating the relationship between both efficiency types.Article Citation - WoS: 1Citation - Scopus: 1Structural and Optical Properties of Thermally Evaporated Ga-In Thin Films(World Scientific Publ Co Pte Ltd, 2014) Isik, Mehmet; Gullu, Hasan HuseyinIn this paper, structural and optical properties of Ga-In-Se (GIS) thin films deposited by thermal evaporation technique have been investigated. The effect of annealing was also studied for samples annealed at temperatures between 300 degrees C and 500 degrees C. X-ray diffraction, energy dispersive X-ray analysis and scanning electron microscopy have been used for structural characterization. It was reported that increase of annealing temperature results with better crystallization and chemical composition of the films were almost same. Optical properties of the films were studied by transmission measurements in the wavelength range of 320-1100 nm. The direct bandgap transitions with energies in the range of 1.52 eV and 1.65 eV were revealed for the investigated GIS films. Photon energy dependence of absorption coefficient showed that there exist three distinct transition regions for films annealed at 400 degrees C and 500 degrees C. The quasicubic model was applied for these transitions to calculate crystal-field splitting and spin-orbit splitting energy values.Book Part Citation - Scopus: 2Molecular Mimicry Study Between Peptides of SARS-CoV-2 and Neutrophil Extracellular Traps-Related Proteins(Elsevier, 2024) Adiguzel,Y.; Shoenfeld,Y.Background Neutrophil extracellular traps (NETs) are observed in both COVID-19 pathology and autoimmune disorders, and molecular mimicry is a mechanism that can lead to an autoimmune response. Methods Similar sequences between SARS-CoV-2 proteins and 5 proteins (plasminogen receptor KT: PLRKT, myeloperoxidase: MPO, proteinase 3: PR-3, neutrophil elastase: NE, matrix metalloproteinase 9: MMP-9) that are present in NETs were searched. Human and SARS-CoV-2 sequence pairs were identified. Those among the identified sequence pairs, which are predicted as strong-binding peptides or epitopes of the same selected MHC class I and class II alleles, were predicted. Results In the case of MHC class I alleles, similar PLRKT and SARS-CoV-2 peptide sequences with high predicted-affinities to HLA-A*24:02, HLA-B*08:01, and HLA-B*15:01; similar MPO and SARS-CoV-2 peptide sequences with strong predicted-affinities to HLA-A*01:01, HLA-A*26:01, and HLA-B*15:01; and similar MMP-9 and SARS-CoV-2 peptide sequences with elevated predicted-affinities to HLA-B*39:01 were predicted. In the case of MHC class II alleles, similar PLRKT and SARS-CoV-2 peptide sequences with high predicted-affinities to HLA-DPA1*02:01/DPB1*01:01 were predicted. Conclusion This work is a proof-of-concept study, which revealed the potential involvement of molecular mimicry in NET pathology within susceptible individuals, in the case of being infected with SARS-CoV-2, leading to autoimmunity. © 2024 Elsevier B.V. All rights reserved.Article Citation - WoS: 6Citation - Scopus: 5Synthesis of a regular polymer containing pseudo-polyether cages(Elsevier Science Sa, 2005) Cihaner, A; Önal, AMA new compound consisting of 2-thienyl units linked by polyether bridge has been synthesized and its electrochemical polymerization was performed via constant potential electrolysis (CPE) in an electrolytic solution containing 0.1 M tetrabutylammonium hexafluorophosphate (TBAPF(6)) dissolved in CH3CN. Chemical polymerization was carried out using FeCl3 as oxidizing agent. It is found that both methods gave the same polymer product without any cleavage of the polyether bridge between thiophene (Th) rings. Although as synthesized polymers exhibited no conductivity, they gain conductivity via chemical doping using 12 vapor exposure. The polymers were characterized using FTIR spectroscopic technique and 12 doping was monitored using in-situ electron spin resonance (ESR) spectroscopy. Thermal behavior of electrochemically prepared polymer was investigated using differential scanning calorimetry, DSC and thermogravimetric analysis, TGA. (c) 2005 Elsevier B.V. All rights reserved.Article Citation - Scopus: 2The Effects of Paddy Cultivation and Microbiota Members on Arsenic Accumulation in Rice Grain(Mdpi, 2023) Ersoy Omeroglu, Esra; Bayer, Asli; Sudagidan, Mert; Ozalp, Veli Cengiz; Yasa, IhsanAccess to safe food is one of the most important issues. In this context, rice plays a prominent role. Because high levels of arsenic in rice grain are a potential concern for human health, in this study, we determined the amounts of arsenic in water and soil used in the rice development stage, changes in the arsC and mcrA genes using qRT-PCR, and the abundance and diversity (with metabarcoding) of the dominant microbiota. When the rice grain and husk samples were evaluated in terms of arsenic accumulation, the highest values (1.62 ppm) were obtained from areas where groundwater was used as irrigation water, whereas the lowest values (0.21 ppm) occurred in samples from the stream. It was observed that the abundance of the Comamonadaceae family and Limnohabitans genus members was at the highest level in groundwater during grain formation. As rice development progressed, arsenic accumulated in the roots, shoots, and rice grain. Although the highest arsC values were reached in the field where groundwater was used, methane production increased in areas where surface water sources were used. In order to provide arsenic-free rice consumption, the preferred soil, water source, microbiota members, rice type, and anthropogenic inputs for use on agricultural land should be evaluated rigorously.Article Citation - WoS: 2Citation - Scopus: 2Perspectives on Monetary Policy and Cost of Capital: Evidence From Turkey(de Gruyter Poland Sp Zoo, 2017) Turguttopbas, NeslihanThe target of monetary policy is generally set as to create an environment of manageable employment and affordable long-term interest rates. However, priorities of central banks may differ depending on economic and financial circumstances of individual countries. Modern approaches to monetary policy transmission can be grouped under two headings, Money View and Credit View. The money view concentrates on interest rates to explain the effects of monetary policy on aggregate spending by creating an interest rate channel. The credit channel transmission approach focuses on the supply of credits by banks following a monetary policy shift in interest rates. In 2010, the Central Bank of Turkey (CBT) developed an interest rate corridor shaped by one-week and overnight repo lending to the financial banks to absorb excessive volatility caused by short-term capital inflows. Under this framework, the CBT implements its monetary policy in two ways; firstly it can alter the interest rates of weekly repo as well as O/N lending rate. Secondly, it can configure the funding structure it provides to the financial intermediaries. In such a framework, the interest rate transmission mechanism has been operated by two benchmark interest rates, one of which is the weighted average of the cost of funds provided by the CBT and the other is the interest rate in Borsa Istanbul (BIST) money market transactions at an overnight maturity. There is a strong co-movement between the interest rates and they are affected by the movements in the CBT lending rate in both directions. Interest rates applied to deposits and loans by banks are affected by the policy rate (CBT Average Funding Rate) and the market rate (BIST O/N Repo Rate).Article Citation - WoS: 77Citation - Scopus: 78Electrical Properties of Al/Pcbm:zno Heterojunction for Photodiode Application(Elsevier Science Sa, 2020) Gullu, H. H.; Yildiz, D. E.; Kocyigit, A.; Yildirim, M.In this paper, the electrical characteristics of spin-coated PCBM:ZnO interlayered Al/PCBM:ZnO/Si diode are investigated under the aim of photodiode application. Under dark condition, the diode shows about four orders in magnitude rectification rate and diode illumination results in efficient rectification with increase in intensity. The analysis of current-voltage curve results a non-ideal diode characteristics according to the thermionic emission model due to the existence of parasitic resistances and interface states. The measured current-voltage values are used to extract the barrier height and ideality factor under dark and illumination conditions. Under illumination, photo-generated carriers contribute to the current flow and linear photo-conductivity behavior in photo-current measurements with illumination shows the possible use of hybrid PCBM:ZnO layer in Si-based photodiodes. In addition, change in the series and shunt resistance values under illumination is found to be effective in this light-sensing behavior of the diode. This characteristic is also observed from the typical on/off illumination switching behavior for the photodiodes in transient photo-current, photo-capacitance and photo-conductance measurements with the quick response to the illumination. The deviations from ideality are also discussed by means of distribution of interface states and series resistance depending on the applied frequency and bias voltage. (C) 2020 Elsevier B.V. All rights reserved.
