Sakarya University of Applied Sciences AXSIS
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A new deep learning-based GUI design and implementation for automatic detection of brain strokes with CT images
No full textBrain stroke is a disease that can occur in almost any age group, especially in people over 65. There are two main types of strokes: ischemic stroke and hemorrhagic stroke. Blockage of brain vessels causes ischemic stroke, while rupture of blood vessels in or around the brain causes hemorrhagic stroke. According to the World Health Organization, 5 million people die annually from this disease; 85% of these 5 million are paralyzed by ischemic stroke and 15% by hemorrhagic stroke. For these reasons, especially in the early diagnosis and treatment of ischemic stroke, patients can lead to more comfortable lives. In this study, we evaluate the effectiveness of real-time object detection algorithms for the detection of brain strokes in computed tomography images and propose an artificial intelligence-supported system for busy physicians to quickly analyze computed tomography images. The aim of this study is to compare the performance of YOLOv7, YOLOv8, and YOLOv9 models in the detection of ischemic and hemorrhagic strokes from brain computed tomography images, to compare the performance of YOLO-based algorithms known as real-time object detection networks in segmentation with other segmentation networks known as U-Net and U-Net variants and Mask-RCNN algorithms, and to develop a system that doctors can use to analyze stroke computed tomography images. In this study, 6951 anonymized brain computed tomography slices obtained from the Turkish Ministry of Health were used. The YOLOv7, YOLOv8, and YOLOv9 models are trained using deep learning algorithms. Model training and testing processes were performed with the PyTorch deep learning framework and CUDA acceleration. The dataset consists of anonymized brain computed tomography images collected between 2019 and 2020. Experimentally, three different studies were conducted using ischemic stroke-health images, hemorrhagic stroke-health images, and ischemic stroke–hemorrhagic stroke-health images together for comparison with the literature. In all studies, the YOLOv9-Seg model is successful. In the ischemic stroke-health images study, 99.50% segment [email protected] success was achieved; in the hemorrhagic stroke-health images study, 99.49% segment [email protected] success; and in the ischemic stroke–hemorrhagic stroke-health images study, %99.71 segment [email protected] success was achieved. The YOLOv7 and YOLOv8 models also exhibited high accuracy rates but lagged behind the YOLOv9-Seg model. These findings suggest that the YOLOv9-Seg model is the most suitable model for the detection and segmentation of ischemic and hemorrhagic strokes in brain CT images. The real-time processing capability of the model will help to make fast and accurate decisions in emergency medical interventions. In addition, this study has shown that YOLO-based models can be used effectively in health data. It is thought that the use of the model in clinical applications will make significant contributions to early diagnosis and treatment processes. © The Author(s), under exclusive licence to EDP Sciences, Springer-Verlag GmbH Germany, part of Springer Nature 2024
Fabrication of Free-Standing Hybrid Composite High Capacity Cathodes for Li−S Batteries with Nickel Oxide Polysulfide Adsorbent
No full textThis study focuses on enhancing lithium-sulfur (Li−S) battery performance by using nickel(II) oxide (NiO), as polysulfide adsorbent to mitigate the shuttle effect. Polysulfides have been shown to effectively adsorb onto the hydrophilic surfaces of polar metal oxides and thus suppress this effect. In this work, a NiO – reduced Graphene Oxide/Sulfur (NiO-rGO/S) hybrid composite paper was developed for use as a binder-free, flexible cathode. The characterization of the composite films was done through Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, thermogravimetric analysis (TG), field emission gun scanning electron microscopy (FEG-SEM), energy dispersive x-ray spectroscopy (EDS) and x-ray diffraction (XRD). To test adsorption of polysulfides by NiO, ultraviolet-visible (UV-Vis) spectroscopy was applied. Electrochemical performance tests of CR2032 cells were also conducted by cyclic voltammetry (CV), charge-discharge tests, electrochemical impedance spectroscopy (EIS). The NiO-rGO/S cathode, particularly the one containing 2 % NiO, exhibited remarkable performance. It delivered an initial discharge capacity of 1230 mAh g−1, maintaining 1029 mAh g−1 after 300 cycles, with a high capacity retention of 83.1 %. This suggests that the NiO-rGO/S hybrid composite is a promising candidate for improving the efficiency and lifespan of Li−S batteries. © 2024 The Authors. ChemElectroChem published by Wiley-VCH GmbH
Sol–gel fabrication of thermoelectric P-type Ca2.5Ag0.3Ce0.2Co4O9 materials for aerospace applications
No full textThe article provides a comprehensive description of the synthesis and characterization of Ca2.5Ag0.3Ce0.2Co4O9 semiconducting ceramics for potential application in thermoelectric generators, particularly in the aerospace industry. These materials were synthesized using the sol–gel method, with distilled water serving as the solvent and citric acid monohydrate incorporated into expedited gel formation. The pH and turbidity values of solutions were monitored through a pH meter and turbidimeter, respectively. The produced xerogel was subjected to drying at 200°C for 2 h in an air atmosphere to remove residual moisture and volatile by-products. The desiccated powders were then heat-treated at 800°C for 2 h under ambient air conditions, yielding the final Ca2.5Ag0.3Ce0.2Co4O9 compound. Thermal processing of the resulting pellets was carried out at 900°C for 24 h to fabricate bulk samples. Comprehensive characterization was performed to assess thermal, structural, microstructural, and thermoelectric behaviors via DTA-TG, XRD, XPS, SEM, and TM machines. It was found that at 800°C, a maximum power factor of.24 mW/m·K2 was achieved, derived from a Seebeck coefficient of 214.30 µV/K and electrical resistivity of 19.05 mΩ·cm at the same temperature. The synthesized ceramic materials exhibit promising thermoelectric efficiency, making them suitable for thermoelectric generator production. © 2025 The Author(s). International Journal of Applied Ceramic Technology published by Wiley Periodicals LLC on behalf of American Ceramics Society
OPTIMIZATION OF WELDING PARAMETERS OF ELECTRICAL RESISTANCE SPOT WELDED 6082-7075 ALUMINIUM JOINTS USING THE TAGUCHI METHOD; [OPTIMIZACIJA PARAMETROV ELEKTRO-UPOROVNEGA TOČKOVNEGA VARJENJA ZLITIN NA OSNOVI ALUMINIJA TIPOV 6082 IN 7075 S POMOČJO TAGUCHIJEVE METODE]
No full textIn this study, aluminium alloys of AA6082 and AA7075 series were welded with resistance spot welding. Effects of welding current intensity, welding time, and electrode pressure on the tensile strength and microstructure were examined, and their optimized values were determined using the Taguchi method. While performing optimization, the L24 orthogonal array was used with the Taguchi method. With this array, the signal/noise (S/N) ratio became the determining factor in controlling the optimization results. Comparing the experimental procedures and analysis results, the results obtained from the real application and Taguchi analysis were found out to be similar. © 2024 The Author(s). Except when otherwise noted, articles in this journal are published under the terms and conditions of the Creative Commons Attribution 4.0 International License (CC BY 4.0)
The Effect of Massage, Acupressure and Reflexology on Restless Legs Syndrome Severity and Sleep Quality in Patients Receiving Haemodialysis Treatment: A Systematic Review and Meta-Analysis
No full textAim: This study aimed to review massage, acupressure and reflexology interventions applied to haemodialysis patients with restless legs syndrome and to examine the effects of these interventions on sleep quality. Design: A systematic review and meta-analysis. Data Sources: A systematic literature search was conducted on databases ScienceDirect, Web of Science, Cochrane Central Register of Controlled Trials, EBSCO and PubMed. Methods: The Modified Jadad scale was used. The statistical analysis was conducted using the Stata 15.0 software, with the aim of evaluating heterogeneity between studies using both chi-square and I2 statistics. The risk of bias in the included studies was assessed using both the Cochrane risk of bias assessment tool and statistical tests. A funnel plot was used to detect potential publication bias, which is indicated by an asymmetry in the plot. The Egger regression test was also performed to evaluate publication bias. Results: Twelve studies were selected for the meta-analysis. All studies included in this meta-analysis were of good quality. In the subgroup analysis, it was determined that massage and acupressure reduced the severity of restless legs syndrome as a result of the intervention, while reflexology had no effect. Interventions did not affect the sleep quality of patients. Restless legs syndrome severity was significantly reduced in studies using oil and in studies that intervened for more than 15 min per session. Conclusion: Interventions applied to haemodialysis patients with restless legs syndrome can reduce the severity of restless legs syndrome. It is recommended to conduct randomised controlled trials that determine the effects of methods on restless legs syndrome severity and sleep quality in haemodialysis patients. © 2025 The Author(s). Nursing Open published by John Wiley & Sons Ltd
Thermomechanical free vibration buckling of FG graphene-reinforced doubly-curved sandwich shells
No full textThis study explores the thermomechanical free vibration and buckling behavior of doubly-curved sandwich shell structures with a core of FG graphene-reinforced foam and metal or ceramic face layers. Using Hamilton's principle and a Navier-type solution method, the governing equations and boundary conditions for simply supported, functionally graded doubly-curved shells are derived. The numerical results are validated through comparison with existing literature. The analysis focuses on the effects of the material grading index, foam void ratio, graphene volume fraction, side-to-thickness ratio, and temperature variations. Notably, it was observed that as R1 increases from α to 10α, the buckling temperature significantly decreases, highlighting a reduction in thermal stability with increasing radii or inverse correlation between R1 and R2. These findings reveal unexpected thermal instability trends that could influence future design considerations for high-temperature applications. This study provides novel insights into the thermomechanical behavior of advanced sandwich structures, offering valuable contributions to the field in light of evolving technological needs. © 2025 Elsevier Lt
Relationship of Autophagic Dysfunction With the Quality of Life and Sleep, Depression and Disease Severity in Patients With Restless Legs Syndrome
No full textIntroduction: Restless legs syndrome (RLS) is a frequently encountered neurological illness that has no effective treatment and imposes an enormous socioeconomic burden. Autophagy is essential for the maintenance of healthy cellular physiology, cell viability, and defense against pathogenic conditions. However, there is no study investigating the possible role of autophagy-related proteins (ATGs) in RLS patients. Therefore, we aimed to investigate the expression and diagnostic potential of ATG3 and ATG5, as well as the relationships between these proteins and laboratory markers, depression, disease score, quality of life, and sleep in RLS patients. Methods: A total of 49 patients with RLS and 26 healthy individuals were recruited for the current study. The severity of the disease was assessed using the international RLS rating scale. All participants were administered the Pittsburgh Sleep Quality Index, the Quality-of-Life Scale, and the Beck Depression Inventory. The enzyme-linked immunosorbent assay was employed to quantify the expressions of ATG3 and ATG5. Results: Serum ATG3 and ATG5 expressions were significantly upregulated in RLS patients compared to healthy controls (p = 0.005) and upregulated ATG3 and ATG5 expressions were relationship with the severity of the disease (p < 0.05). ATG3 was substantially correlated with the quality of sleep, whereas ATG5 was correlated with the quality of life and depression status (p < 0.05). The ROC curve analysis demonstrated that ATG3 expressions over 3146.5 ng/mL and ATG5 expressions over 4732.5 ng/mL may predict the presence of RLS (p < 0.01). Conclusion: We report for the first time that autophagy may have a significant impact on the development of RLS. © 2025 The Author(s). Brain and Behavior published by Wiley Periodicals LLC
A new lab-made screen-printed electrode system based on reduced graphene oxide-subphthalocyanine functionalized with ferrocene for electrochemical detection of acetaminophen
No full textAcetaminophen (Ac) is a pharmaceutically active ingredient widely used in the treatment of pain and fever. However, an acute oral overdose of more than 12 g of Ac is considered a toxic dose and poses a high risk of liver damage. This study presents the development of a new laboratory-made screen-printed electrode modified with reduced graphene oxide (rGO)-subphthalocyanine-functionalized with ferrocene (SubPc-Fc) to detect Ac. Initially, subphthalocyanine (SubPc) was synthesized using a known method from the literature and was then functionalized with ferrocene (Fc). Subsequently, this functionalized compound was combined with rGO to form a composite structure (rGO-SubPc-Fc). A laboratory-made screen-printing electrode (LabSPE) was successfully created by using carbon and silver conductive inks applied to a polycarbonate substrate through the screenprinting process. Then, the surface of LabSPE was modified with rGO-SubPc-Fc composite and made ready for the electrochemical determination of Ac. The electrochemical results revealed that the rGO-SubPc-Fc composite exhibited a remarkable sensing behavior towards the oxidation of Ac with a working range from 0.05 mu M to 200 mu M, and a detection limit of 0.01 mu M. The selectivity of the proposed sensor (rGO-SubPc-Fc/LabSPE) for Ac detection in the presence of possible interfering compounds such as uric acid, epinephrine, ascorbic acid, dopamine, and some ions was also examined. The practical suitability of rGO-SubPc-Fc/LabSPE in real sample analysis was tested on two different types of human drug samples and appreciable recovery results were obtained in the range of 102.02-103.94 %. In drug sample analysis, the proposed method was compared with the spectrophotometric method, and satisfactory results were achieved
Apatite-wollastonite glass-ceramics containing B2O3 and Na2O: Potential bioactive material for tissue protection during radiation therapy procedures
No full textIn this study, an attempt to expand available data and functionality of apatite-wollastonite glass ceramics (AW GCs) in medical therapy and bone engineering by estimating and analysing the physical, structural, fast neutron and gamma interaction properties of B2O and Na2O doped AW GCs is presented. The pristine (AW) and (20 wt% B2O3 and 30 wt% Na2O) doped AW GC (AW-B20-N30) samples were prepared using the cold isostatic press method. The samples were subject of structural and physical characterisation through experimental procedures, while their radiation interaction parameters were obtained following standard theoretical models. Samples’ densities were calculated as 2.917 and 2.613 g/cm3, while the Vickers hardness was 553 and 518 HV for AW and AW-B20-N3, respectively. The structure of the samples revealed that Na2O formed the brianite phase inserted in the apatite structure. The mass and linear attenuation coefficients fluctuated within the ranges, 0.0232-13.6853 cm2/g and 0.0676-39.92 cm-1 for AW and 0.021-8.313 cm2/g and 0.055-21.7223 cm-1 for AW-B20-N30, respectively. The half- and tent-value layers increased from about 0.02 to 10.25 cm and 0.06 to 34.05 cm for AW; for AW-B20-N30, the increase is from 0.032 to 12.61 cm and 0.11 to 41.88 cm, respectively. AW was more effective for shielding photons and fast neutrons, and had lower gamma buildup factors compared to AW-B20-N30. The study showed doping AW with B2O and Na2O could be optimised to get equivalent bone material in radiation studies. The AW GCs also showed better shielding effectiveness compared to some traditional shields and could therefore be applied for shielding tissues outside the target volume in radiation therapy. © 202
Effect of silicone, molybdenum disulfide, and multi-walled carbon nanotube on the tribological, mechanical, and thermal properties of polyamide 66/carbon fibre composites
No full textThe effect of silicone, molybdenum disulfide (MoS2), and multiwalled carbon nanotubes (MWCNT) on the mechanical, thermal, and tribological characteristics of polyamide 66 (PA66) composites reinforced with carbon fibre (CF) was extensively examined in this paper. An injection molding machine was used to make test samples for mechanical, thermal, and tribological testing after the twin-screw extruder was used to create the composite materials. To evaluate the mechanical behaviours of PA66 and composite samples, tensile strength (TS) and flexural strength (FS), tensile modulus (TM) and flexural modulus (FM), elongation at break (EB), and impact strength were measured. The TS and TM of PA66/30CF increased by 89.6 % and 374.3 % compared with PA66. PA66/30CF/0.5MWCNT nanocomposites exhibited better tensile (strength of 196.5 and modulus of 23575 MPa, respectively) and flexural (strength of 289 and modulus of 17700 MPa, respectively) properties. DSC analysis indicated that the melting temperature (Tm) of PA66 composites was not affected by adding CF, MWCNT, MoS2 and silicone. In contrast, composites’ crystallisation temperature (Tc) and degree of crystallinity (Xc%) values were higher than those of PA66. The addition of MWCNT, MoS2 and silicone yielded a further increase in Xc, and with 42.4 %, the PA66/30CF/0.5MWCNT/3MoS2 nanocomposite yielded the highest value. The test for pin-on-disk (PoD) wear was conducted under dry sliding conditions, with 0.4, 0.8, and 1.2 m/s of sliding velocity, and a load of 20, 30, and 40 N. The tribological measurements implied that the PA66 composites prepared with 30 wt% of CF, 0.5 wt% MWCNT and 3 wt% MoS2 showed the best friction and wear behavior. The COF of PA66 polymer was around 0.4, while the COF of PA66/CF composites was between 0.25–0.35. The incorporation of MWCNT, MoS2, and silicone into the PA66/30CF composite led to a further decrease in the COF, yielding values ranging between 0.15 and 0.25. It has been deduced that the MWCNT and MoS2 additives improved the service life and thermomechanical durability of PA66 in a distinguishable manner. It was also revealed that the composite reinforced with MWCNT and MoS2 exhibited enhanced wear resistance due to the strong interfacial bonding. © 2025 Elsevier B.V