Araştırma Çıktıları | TR-Dizin | WoS | Scopus | PubMed

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AlN Piezoelectric Quad-Actuators for 2D Optical Micro Scanning
(Taylor & Francis Ltd, 2022) Hah, Dooyoung; 0000-0002-1290-0597; AGÜ, Mühendislik Fakültesi, Elektrik - Elektronik Mühendisliği Bölümü; Hah, Dooyoung; 01. Abdullah Gül University; 02. Mühendislik Fakültesi; 02.05. Elektrik & Elektronik Mühendisliği
Piezoelectric actuation has been one of the frequent choices for optical micro scanning. In most of the cases, lead zirconate titanate (PZT) has been used as the piezoelectric material. However, PZT has a potential issue in biomedical applications due to the content of lead. For this, AlN can be used as an alternative. The main drawback of AlN is its low piezoelectric coefficients. In order to overcome such a drawback, this paper presents a novel actuator configuration, designed for a quasi-static operation mode. Quad-actuators and meander-shaped hinges are the essence of the proposed actuator configuration. Numerical simulation study is carried out to prove the concept of the device. The study also shows that the proposed scanner can have the optical scan angle of 9 degree at a quasi-static mode. Two different scan modes, a raster-like mode and a Lissajous mode are tested, demonstrating the two-dimensional scanning capability of the device.
Citation - WoS: 2
Citation - Scopus: 2
Analysis of Oscillator Phase Noise Effect on High Order QAM Links
(Springer, 2020) Bicici, Cagri; Ozdur, Ibrahim; Cerezci, Osman; 01. Abdullah Gül University
In this work, the effect of oscillator phase noise on the bit error rate (BER) for high order QAM communication systems is analyzed. Two high frequency oscillators are designed, built and tested to get real phase noise data, and a BER simulation of a 1024 QAM signal through a super-heterodyne frequency down-converter is implemented using the measured data from the two oscillators as local oscillator sources for the down-converter. A third frequency source is also added to the simulation to visualize the dramatic effect of phase noise on the system BER analysis.
Citation - WoS: 6
Citation - Scopus: 6
Arsenic Removal From Aqueous Solutions by Ultrafiltration Assisted With Polyacrylamide: An Application of Response Surface Methodology
(Taylor & Francis inc, 2015) Varol, Bekir; Uzal, Nigmet; 01. Abdullah Gül University; 02.03. İnşaat Mühendisliği; 02. Mühendislik Fakültesi
The present work deals with removal of arsenic from aqueous solutions by ultrafiltration assisted with polyacrylamide as an environmental friendly complexing polymer. The system performance was evaluated in relation to quality of permeate in terms of operating variables as feed concentration of arsenic ions (C-o, gL(-1)), ratio of polymer to arsenic (r, w/w), and pH of feed solution. The effect of the operating variables and maximum arsenic removal efficiency was determined by adopting design of experiments and response surface methodology under different conditions for this polymer. The experimental data were analyzed with a second order polynomial model validated by statistical analysis. Based on the response model developed, the maximum removal efficiency, close to 100%, of arsenic ions has been obtained at optimum operating parameters as C-o: 150 gL(-1), r: 2, and pH 10.
Citation - WoS: 1
Citation - Scopus: 3
Biosynthesis of Novel Naphthoquinone Derivatives in the Commonly-Used Chassis Cells Saccharomyces Cerevisiae and Escherichia Coli
(Pleiades Publishing inc, 2021) Wu, W.; Wang, S.; Zhang, H.; Guo, W.; Lu, H.; Xu, H.; Sun, L.; 01. Abdullah Gül University
Naphthoquinones harboring 1,4-naphthoquinone pharmacophore are considered as privileged structures in medicinal chemistry. In pharmaceutical industry and fundamental research, polyketide naphthoquinones were widely produced by heterologous expression of polyketide synthases in microbial chassis cells, such as Saccharomyces cerevisiae and Escherichia coli. Nevertheless, these cell factories still remain, to a great degree, black boxes that often exceed engineers' expectations. In this work, the biotransformation of juglone or 1,4-naphthoquinone was conducted to generate novel derivatives and it was revealed that these two naphthoquinones can indeed be modified by the chassis cells. Seventeen derivatives, including 6 novel compounds, were isolated and their structural characterizations indicated the attachment of certain metabolites of chassis cells to naphthoquinones. Some of these biosynthesized derivatives were reported as potent antimicrobial agents with reduced cytotoxic activities. Additionally, molecular docking as simple and quick in silico approach was performed to screen the biosynthesized compounds for their potential antiviral activity. It was found that compound 11 and 17 showed the most promising binding affinities against Nsp9 of SARS-CoV-2, demonstrating their potential antiviral activities. Overall, this work provides a new approach to generate novel molecules in the commonly used chassis cells, which would expand the chemical diversity for the drug development pipeline. It also reveals a novel insight into the potential of the catalytic power of the most widely used chassis cells.
Citation - WoS: 4
Citation - Scopus: 4
Camera-Based Wildfire Smoke Detection for Foggy Environments
(SPIE - Society of Photo-Optical Instrumentation Engineers, 2022) Tas, Merve; Tas, Yusuf; Balki, Oguzhan; Aydin, Zafer; Tasdemir, Kasim; 01. Abdullah Gül University; 02. 04. Bilgisayar Mühendisliği; 02. Mühendislik Fakültesi
Smoke is the first visible sign of forest fires and the most commonly used feature for early forest fire detection using data from cameras. However, one of the natural challenges is the dense fog that appears in forests, which decreases the detection accuracy or triggers false alarms. In this study, we propose a system with a deep neural network-based image preprocessing approach that significantly improves the smoke segmentation and classification performance by dehazing the camera view. Our experimental results provide that the classification models reach 99% F1 score for the correct classification of smoke when the image dehazing method is used before the training process. The smoke localization system achieves 60% average precision when the mask region-based convolutional neural network is used with the ResNet101-FPN backbone. The proposed approach can be utilized for all smoke segmentation frameworks to increase fire detection performance. (c) 2022 SPIE and IS&T
Citation - Scopus: 1
Characteristics of Germinated Corn Flour and Influence of Germination on Cookie Properties
(Akademiai Kiado Zrt, 2022) Oskaybas-Emlek, B.; Ozbey, A.; Kahraman, K.; 01. Abdullah Gül University; 02.07. Malzeme Bilimi ve Nanoteknoloji Mühendisliği; 02. Mühendislik Fakültesi
The aim of this study was to investigate the effect of germination on the physicochemical, structure, pasting, and morphological properties of corn. Germination improved total phenolic content (TPC) and antioxidant capacity (AC). Scanning electron micrographs (SEM) of flour showed that some starch granule was destroyed with germination. In the same way, pasting values decreased due to changes in the starch granule. FT-IR (Fourier Transform Infrared) spectra confirmed that germination leads to changes in the chemical structure. The XRD (X-ray diffractometer) analysis showed that patterns did not change with germination. In addition, raw and germinated corn flour were used in gluten-free cookie preparation. The cookie dough was evaluated for stickiness. The physical, textural, colour, TPC, and AC of cookie samples were determined. Gluten-free cookies prepared with germinated flour exhibited significantly higher AC due to increase in TPC. Germination could be used to enhance functional properties of corn.
Citation - WoS: 3
Citation - Scopus: 4
Clinical Probe Utilizing Surface Enhanced Raman Scattering
(A V S Amer Inst Physics, 2014) Kim, Jeonghwan; Hah, Dooyoung; Daniels-Race, Theda; Feldman, Martin; 01. Abdullah Gül University; 02. Mühendislik Fakültesi; 02.05. Elektrik & Elektronik Mühendisliği
Conventional Raman scattering is a well-known technique for detecting and identifying complex molecular samples. In surface enhanced Raman scattering, a nanorough metallic surface close to the sample enormously enhances the Raman signal. In previous work, the metallic surface was a thin layer of gold deposited on a rough transparent epoxy substrate. The advantage of the clear substrate was that the Raman signal could be obtained by passing light through the substrate, on to opaque samples simply placed against its surface. In this work, a commercially available Raman spectrometer was coupled to a distant probe. Raman signals were obtained from the surface, and from the interior, of a solid specimen located more than 1 m away from the spectrometer. The practical advantage of this arrangement is that it opens up surface enhanced Raman spectrometry to a clinical environment, with a patient simply sitting or lying near the spectrometer. (C) 2014 American Vacuum Society.
Citation - WoS: 3
Combined Effect of Midostaurin and Sphingosine Kinase-1 Inhibitor on FMS-Like Tyrosine Kinase 3 (FLT3) Wild Type Acute Myeloid Leukemia Cells
(Walter de Gruyter Gmbh, 2022) Sahin, Hande Nur; Adan, Aysun; 01. Abdullah Gül University; 04. Yaşam ve Doğa Bilimleri Fakültesi; 04.02. Moleküler Biyoloji ve Genetik
Objectives Therapeutic potential of clinically approved FLT3 inhibitor midostaurin has been neglected in wild-type FLT3 positive acute myeloid leukemia (AML). Sphingosine kinase-1 (SK-1) having anti-proliferative functions is studied in various cancers, but not in FLT3 wild-type AML. We aimed to develop new therapeutic strategies to combat FLT3 wild-type AML by combining midostaurin with SK-1 inhibitor (SKI II) in THP1 cells. Methods The anti-proliferative effects of midostaurin, SKI II and in combination on THP1 cells were determined by MTT assay. The combination indexes were calculated using calcusyn software. SK-1 expression and PARP cleavage were checked by western blot. Cell cycle distributions (PI staining) and apoptosis (annexin-V/PI dual staining) were assessed by flow cytometry for each agent alone and in combinations. Results Midostaurin decreased SK-1 protein level. Midostaurin, SKI II and certain combinations decreased cell viability in a dose dependent manner. The combined anti-leukemic effects of the aforementioned drug combination afforded additive effect. Co-administration induced both necrosis and apoptosis via phosphatidylserine externalization, PARP cleavage and cell cycle arrest at G0/G1 and S phases. Conclusions Targeting sphingosine kinase-1 together with FLT3 inhibition could be a novel mechanism to increase limited clinic response to midostaurin in wild-type FLT3 overexpressing AML after further pre-clinical studies.
Citation - Scopus: 3
Combined Effect of Midostaurin and Sphingosine Kinase-1 İnhibitor on FMS-Like Tyrosine Kinase 3 (FLT3) Wild Type Acute Myeloid Leukemia Cells
(De Gruyter Open Ltd, 2022) Şahin, Hande Nur; Adan, Aysun; 01. Abdullah Gül University; 04. Yaşam ve Doğa Bilimleri Fakültesi; 04.02. Moleküler Biyoloji ve Genetik
Objectives: Therapeutic potential of clinically approved FLT3 inhibitor midostaurin has been neglected in wild-type FLT3 positive acute myeloid leukemia (AML). Sphingosine kinase-1 (SK-1) having anti-proliferative functions is studied in various cancers, but not in FLT3 wild-type AML. We aimed to develop new therapeutic strategies to combat FLT3 wild-type AML by combining midostaurin with SK-1 inhibitor (SKI II) in THP1 cells. Methods: The anti-proliferative effects of midostaurin, SKI II and in combination on THP1 cells were determined by MTT assay. The combination indexes were calculated using calcusyn software. SK-1 expression and PARP cleavage were checked by western blot. Cell cycle distributions (PI staining) and apoptosis (annexin-V/PI dual staining) were assessed by flow cytometry for each agent alone and in combinations. Results: Midostaurin decreased SK-1 protein level. Midostaurin, SKI II and certain combinations decreased cell viability in a dose dependent manner. The combined anti-leukemic effects of the aforementioned drug combination afforded additive effect. Co-administration induced both necrosis and apoptosis via phosphatidylserine externalization, PARP cleavage and cell cycle arrest at G0/G1 and S phases. Conclusions: Targeting sphingosine kinase-1 together with FLT3 inhibition could be a novel mechanism to increase limited clinic response to midostaurin in wild-type FLT3 overexpressing AML after further pre-clinical studies. © 2022 Elsevier B.V., All rights reserved.
Citation - WoS: 1
Citation - Scopus: 1
The Comparison of Fragility Curves of Moment-Resisting and Braced Frames Used in Steel Structures Under Varying Wind Load
(Turkish Chamber Civil Engineers, 2025) Ozalp, Abdulkadir; Gokdemir, Hande; Ciftci, Cihan; 01. Abdullah Gül University; 02.03. İnşaat Mühendisliği; 02. Mühendislik Fakültesi
In this study, the performance of two different steel structure types (moment-resisting frame and braced frame) under wind loading was compared by addressing the fragility curves of these structure types. To perform this comparison, the dimensions of the members of these structural systems were first determined. Then, nonlinear static pushover analyses were conducted to assess the performance levels of each frame type. After applying these analyses, time-history analyses were performed with 100 different wind loads for each varying equivalent mean wind speed. Afterwards, the probability of exceeding the predetermined structural performance limits of the structure types was determined using Monte Carlo simulation method. Finally, the results of the simulation method were used to adapt the maximum likelihood estimation method to obtain the fragility curves of the structures. To conclude, it has been revealed that the material cost of the structure doubles when diagonal elements are used, but the wind speed required for a 100% collapse probability to occur in the braced frame is twice as high compared to the moment-resisting frame.
Conflict Resolution and Peace Building in the Context of Group Dynamics
(Turkish Psychologists Assoc, 2020) Coymak, Ahmet; Ulug, ozden Melis; Goregenli, Melek; cakal, Huseyin; 01. Abdullah Gül University; 06. İnsan ve Toplum Bilimleri Fakültesi; 06.02. Psikoloji
Citation - Scopus: 2
Developing Empirical Formulae for Scour Depth in Front of Inclined Bridge Piers
(Croatian Association of Civil Engineers, 2023) Fedakar, Halil Ibrahim; Dinçer, A. Ersin; Bozkuş, Zafer; 01. Abdullah Gül University; 02.03. İnşaat Mühendisliği; 02. Mühendislik Fakültesi
Because of the complex flow mechanism around inclined bridge piers, previous studies have proposed different empirical correlations to predict the scouring depth in front of piers, which include regression analysis developed from laboratory measurements. However, because these correlations were developed for particular datasets, a general equation is still required to accurately predict the scour depth in front of inclined bridge piers. The aim of this study is to develop a general equation to predict the local scour depth in front of inclined bridge pier systems using multilayer perceptron (MLP) and radial-basis neural-network (RBNN) techniques. The experimental datasets used in this study were obtained from previous research. The equation for the scour depth of the front pier was developed using five variables. The results of the artificial neural-network (ANN) analyses revealed that the RBNN and MLP models provided more accurate predictions than the previous empirical correlations for the output variables. Accordingly, analytical equations derived from the RBNN and MLP models were proposed to accurately predict the scouring depth in front of inclined bridge piers. Moreover, from the sensitivity analyses results, we determined that the scour depths in front of the front and back piers were primarily influenced by the inclination angle and flow intensity, respectively. © 2023 Elsevier B.V., All rights reserved.
Development of an Optical Measurement System for Surface Depth Measurements and Study of Focus Effect on Determination of Steel Inclusion Content by EN-10247
(SPIE - Society of Photo-Optical Instrumentation Engineers, 2021) Durkaya, Goksel; Kurtuldu, Huseyin; Cetin, Baris; Bal, Burak; 01. Abdullah Gül University; 02.06. Makine Mühendisliği; 02. Mühendislik Fakültesi
Surface inspections are important in steelmaking processes to characterize the final product's quality. We present a method to measure surface depth profile using laser scattering geometry. This technique is used to analyze the focus effect on microscopic analyses of steel inclusions using the EN-10247 standard. The results presented herein offer promising new perspectives for the metal manufacturing industry through cost-effective solutions that attain quasi in-line process inspection capabilities. (C) 2021 Society of Photo-Optical Instrumentation Engineers (SPIE)
Citation - WoS: 4
Citation - Scopus: 4
Differential in Vitro Anti-Leukemic Activity of Resveratrol Combined With Serine Palmitoyltransferase Inhibitor Myriocin in FMS-Like Tyrosine Kinase 3-Internal Tandem Duplication (FLT3-LTD) Carrying AML Cells
(Springer, 2022) Ersoz, Nur Sebnem; Adan, Aysun; 01. Abdullah Gül University; 04. Yaşam ve Doğa Bilimleri Fakültesi; 04.02. Moleküler Biyoloji ve Genetik
Treatment of FMS-like tyrosine kinase 3 (FLT3)-internal tandem duplication (ITD) AML is restricted due to toxicity, drug resistance and relapse eventhough targeted therapies are clinically available. Resveratrol with its multi-targeted nature is a promising chemopreventive remaining limitedly studied in FLT3-ITD AML regarding to ceramide metabolism. Here, its cytotoxic, cytostatic and apoptotic effects are investigated in combination with serine palmitoyltransferase (SPT), the first enzyme of de novo pathway of ceramide production, inhibitor myriocin on MOLM-13 and MV4-11 cells. We assessed dose-dependent cell viability, flow cytometric cell death and cell cycle profiles of resveratrol in combination with myriocin by MTT assay, annexin-V/PI staining and PI staining respectively. Resveratrol's dose-dependent effect on SPT protein expression was also checked by western blot. Resveratrol decreased cell viability in a dose- dependent manner whereas myriocin did not affect cell proliferation effectively in both cell lines after 48h treatments. Although resveratrol induced both apoptosis and a significant S phase arrest in MV4-11 cells, it triggered apoptosis and non-significant S phase accumulation in MOLM-13 cells. Co-administrations reduced cell viability. Increased cytotoxic effect of co-treatments was further proved mechanistically through induction of apoptosis via phosphatidylserine relocalization. The cell cycle alteration in co-treatment was significant with an S phase arrest in MV4-11 cells, however, it was not effective on cell cycle progression of MOLM-13 cells. Resveratrol also increased SPT expression. Overall, modulation of SPT together with resveratrol might be the possible explanation for resveratrol's action. It could be an integrative medicine for FLT3-ITD AML after investigating its detailed mechanism of action in relation to de novo pathway of ceramide production.
Citation - WoS: 6
Citation - Scopus: 7
Dimensionality Reduction for Protein Secondary Structure and Solvent Accesibility Prediction
(World Scientific Publ Co Pte Ltd, 2018) Aydin, Zafer; Kaynar, Oguz; Gormez, Yasin; 01. Abdullah Gül University; 02. 04. Bilgisayar Mühendisliği; 02. Mühendislik Fakültesi
Secondary structure and solvent accessibility prediction provide valuable information for estimating the three dimensional structure of a protein. As new feature extraction methods are developed the dimensionality of the input feature space increases steadily. Reducing the number of dimensions provides several advantages such as faster model training, faster prediction and noise elimination. In this work, several dimensionality reduction techniques have been employed including various feature selection methods, autoencoders and PCA for protein secondary structure and solvent accessibility prediction. The reduced feature set is used to train a support vector machine at the second stage of a hybrid classifier. Cross-validation experiments on two difficult benchmarks demonstrate that the dimension of the input space can be reduced substantially while maintaining the prediction accuracy. This will enable the incorporation of additional informative features derived for predicting the structural properties of proteins without reducing the accuracy due to overfitting.
Experimental Analysis of Absolute Phase Noise of a Harmonically Mode-Locked Semiconductor Laser
(Natl Inst Optoelectronics, 2018) Ozharar, S.; Ozdur, I.; 01. Abdullah Gül University
In this work, we have designed and experimentally characterized the absolute phase noise of a fiber coupled semiconductor ring laser at 1550 nm, actively mode-locked at 10 GHz by an external RF oscillator. The dependency of mode-locked laser phase noise to the external RF oscillator phase noise and laser cavity length is investigated using different RF sources and cavity lengths. A timing jitter of 14.6 fs (1 kHz to 1 MHz) has been measured at 10 GHz with a total cavity length of 315 meters.
Gender Violence and the Transnational Politics of the Honor Crime
(Sage Publications inc, 2022) Donmez, Rasim; 01. Abdullah Gül University
Citation - WoS: 1
Citation - Scopus: 1
A Generalized PID Controller for High-Order Dynamical Systems
(Slovak Univ Technology, 2021) Ablay, Gunyaz; 01. Abdullah Gül University
This paper introduces a generalized PID type controller for controlling high-order dynamical systems. An optimal generalized PID control design method is developed to provide a simplified high-order output feedback control design procedure and tunable response characteristics. The controller design procedure is reduced to the specification of the desired natural frequency and the solution of a polynomial equation. The control method is capable of providing a desired control performance under set-point and disturbance variations. The performance of the proposed control method is implemented on some unstable and nonlinear mechatronic systems to illustrate the robustness, effectiveness and feasibility of the method.
Citation - Scopus: 4
Genetic Variants in Genes Correlated to the PI3K/AKT Pathway: The Role of ARAP3, CDH5, KIF and RELN Primary Lymphedema
(International Society of Lymphology, 2023) Dundar, Mehmet Sait; Belanová, I.; Bonetti, Gabriele; Gelanová, V.; Kozáčiková, R.; Vešelényiová, Dominika; Donato, Kevin; 01. Abdullah Gül University
Genetic anomalies affecting lymphatic development and function can lead to lymphatic dysfunction, which could manifest as lymphedema- Understanding the signaling pathways governing lymphatics function is crucial for developing targeted diagnostic and therapeutic interventions. This study aims to characterize genetic variants in genes involved in the PUKIAKT signaling pathway, which plays a critical role in lymphangiogenesis. 408 patients diagnosed with primary lymphedema were sequenced usinga next-generation sequencing (NGS) gene panel composed of 28 diagnostic genes and 71 candidate genes. The analysis revealed six variants in genes RFLN, ARAP3,CDHS and K1F11. Five of these variants have never been reported in the literature. All these genes have been correlated to lymphatic activity and are involved in the P13K/AKT pathway. As the P13K/AKT signaling pathway plays an essential role in lymphangiogenesis and lymphatic function, genetic variants in genes correlated to this pathway could lead to lymphedema. Our findings underscore the potential of the P13K/AKT pathway in lymphedema pathogenesis, supporting the role of RELN,ARAP3,CDH5,and KIF11 as diagnostic and therapeutic targets. © 2024 Elsevier B.V., All rights reserved.
Citation - WoS: 4
Genetic Variants in Genes Correlated to the PI3K/AKT Pathway: The Role of ARAP3, CDH5, KIF22 and RELN in Primary Lymphedema
(Lymphology, 2023) Dundar, M. S.; Belanova, I.; Bonetti, G.; Gelanova, V.; Kozacikova, R.; Veselenyiova, D.; Michelini, S.; 01. Abdullah Gül University
Genetic anomalies affecting lymphatic development and function can lead to lym- phatic dysfunction, which could manifest as lymphedema. Understanding the signaling pathways governing lymphatics function is crucial for developing targeted diagnostic and therapeutic interventions. This study aims to characterize genetic variants in genes involved in the PI3K/AKT signaling pathway, which plays a critical role in lymphangiogenesis. 408 patients diagnosed with primary lymphedema were sequenced using a next-generation se- quencing (NGS) gene panel composed of 28 diagnostic genes and 71 candidate genes. The analysis revealed six variants in genes RELN, ARAP3, CDH5, and KIF11. Five of these vari- ants have never been reported in the literature. All these genes have been correlated to lym- phatic activity and are involved in the PI3K/ AKT pathway. As the PI3K/AKT signaling pathway plays an essential role in lymphangio- genesis and lymphatic function, genetic vari- ants in genes correlated to this pathway could lead to lymphedema. Our findings underscore. the potential of the PI3K/AKT pathway in lymphedema pathogenesis, supporting the role of RELN, ARAP3, CDH5, and KIF11 as diag- nostic and therapeutic targets.

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