Recep Tayyip Erdoğan Üniversitesi Kurumsal Akademik Arşivi
DSpace@RTEÜ, Recep Tayyip Erdoğan Üniversitesi tarafından doğrudan ve dolaylı olarak yayınlanan; kitap, makale, tez, bildiri, rapor, araştırma verisi gibi tüm akademik kaynakları uluslararası standartlarda dijital ortamda depolar, Üniversitenin akademik performansını izlemeye aracılık eder, kaynakları uzun süreli saklar ve yayınların etkisini artırmak için telif haklarına uygun olarak Açık Erişime sunar.
Güncel Gönderiler
Category-aware two-stage divide-and-ensemble framework for sperm morphology classification
(Multidisciplinary Digital Publishing Institute (MDPI), 2025) Türkoğlu, Aydın Kağan; Serbes, Görkem; Uzun, Hakkı; Aktaş, Abdulsamet; Yiğit, Merve Hüner; İlhan, Hamza Osman
Introduction: Sperm morphology is a fundamental parameter in the evaluation of male infertility, offering critical insights into reproductive health. However, traditional manual assessments under microscopy are limited by operator dependency and subjective interpretation caused by biological variation. To overcome these limitations, there is a need for accurate and fully automated classification systems. Objectives: This study aims to develop a two-stage, fully automated sperm morphology classification framework that can accurately identify a wide spectrum of abnormalities. The framework is designed to reduce subjectivity, minimize misclassification between visually similar categories, and provide more reliable diagnostic support in reproductive healthcare. Methods: A novel two-stage deep learning-based framework is proposed utilizing images from three staining-specific versions of a comprehensive 18-class dataset. In the first stage, sperm images are categorized into two principal groups: (1) head and neck region abnormalities, and (2) normal morphology together with tail-related abnormalities. In the second stage, a customized ensemble model—integrating four distinct deep learning architectures, including DeepMind’s NFNet-F4 and vision transformer (ViT) variants—is employed for detailed abnormality classification. Unlike conventional majority voting, a structured multi-stage voting strategy is introduced to enhance decision reliability. Results: The proposed framework consistently outperforms single-model baselines, achieving accuracies of 69.43%, 71.34%, and 68.41% across the three staining protocols. These results correspond to a statistically significant 4.38% improvement over prior approaches in the literature. Moreover, the two-stage system substantially reduces misclassification among visually similar categories, demonstrating enhanced ability to detect subtle morphological variations. Conclusions: The proposed two-stage, ensemble-based framework provides a robust and accurate solution for automated sperm morphology classification. By combining hierarchical classification with structured decision fusion, the method advances beyond traditional and single-model approaches, offering a reliable and scalable tool for clinical decision-making in male fertility assessment.
Microplastics in dairy products: occurrence, characterization, contamination sources, detection methods, and future challenges
(Multidisciplinary Digital Publishing Institute (MDPI), 2025) Gürmeriç, Hüseyin Ender; Başaran, Burhan
In this study, data from 17 studies reporting the presence of microplastics in milk and dairy products in the literature were examined with a product-based systematic approach. In addition, geographical comparisons were made between different countries. In milk and dairy products, the concentration of microplastics has been reported to exhibit a broad range, extending from non-detectable levels to as high as 10,040 MPs per kilogram, contingent upon the specific product types. Milk powder (especially baby milk powder) stands out as the riskiest product group in terms of microplastic content. Although the sizes and colors of the detected microplastics vary significantly, the fiber form is generally predominant. While polyethylene, polypropylene, polyamide and polyester are among the polymers frequently detected, high-temperature-resistant industrial polymers such as polytetrafluoroethylene, polysulfone, polyurethane were also encountered. In addition, the presence of some polymers (such polyvinyl chloride, polyurethane) that are toxicologically risky for human health was reported in the studies. In addition, the study evaluated the chemical, enzymatic and physical methods used for the separation and identification of MPs; the advantages and limitations of FT-IR, Raman and other analysis techniques were revealed. This study reveals that MP contamination in milk and dairy products is a multidimensional problem. The findings show that milk and dairy products are highly susceptible to plastic contamination at every stage of production.
Size effect and damage mechanisms in cementitious tungsten tailing backfill materials with varying hydroxypropyl methyl cellulose dosages
(University of Science and Technology Beijing, 2025) Zha, Tao; Cao, Shuai; Yılmaz, Erol
The problems of tailings storage and high-stress conditions in deep mining have emerged as critical factors that limit the security, efficiency, and sustainability of such mines. This study explores the potential to utilize tungsten tailings to create cementitious backfill (CTB) materials and investigates the macroscopic strength features and microscopic damage evolution mechanisms of different-sized CTBs with varying dosages of hydroxypropyl methyl cellulose (HPMC). Specimens with bottom diameters of 50, 75, and 100 mm are combined with HPMC dosages of 0, 0.15wt%, 0.25wt%, and 0.35wt%. A diameter/height ratio of 1:2 is maintained for all CTB specimens. The experimental results show that as the HPMC dosage is increased from 0 to 0.35wt%, the uniaxial compressive strength (UCS) of the CTBs decreases significantly in a linear manner. The 75 mm × 150 mm CTB specimen exhibits relatively high plasticity and toughness, with good plastic deformation and energy absorption capabilities, indicating significant size effects. HPMC introduces connected bubbles during the CTB pouring process, but it exhibits anti-segregation and anti-bleeding characteristics, thus reducing tailing settling. The hydration reaction of the CTB doped with HPMC is more uniform, and the Ca/Si atomic ratio dispersion at different sites is smaller. The three CTB sizes all exhibit combined tensile and shear failure, with the 75 mm × 150 mm specimen exhibiting macroscopic tensile cracks and relatively few shear cracks. At the micro-scale, excessive ettringite and hydrated calcium silicate are interwoven and fuse, and the tungsten tailings are tightly wrapped. These results provide valuable data and notional insights for optimizing the fluidity of the backfill, and elucidate the strength and damage evolution of solidified materials during filling and extraction. This study contributes to the advancement of green, economical, safe, and sustainable mining practices.
Is GDF15 a feasible biomarker in sepsis?
(Multidisciplinary Digital Publishing Institute (MDPI), 2025) Yiğit, Ertuğrul; Şimşek, Mehmet Akif; Hüner Yiğit, Merve; Akça, Görkem; Sönmez, Berat; Uzun, Hakkı
Background/Objectives: Sepsis is a high-mortality syndrome characterized by organ dysfunction resulting from a dysregulated host response to infection. This study aimed to evaluate the potential of growth differentiation factor 15 (GDF15), a stress-inducible cytokine, as a biomarker in patients diagnosed with urosepsis. Methods: A total of 13 patients diagnosed with urosepsis, based on an increase of ≥2 points in the Sequential Organ Failure Assessment (SOFA) score and positive urine culture, were included in the study. Daily blood samples were collected from patients for 10 days, and serum levels of GDF15, procalcitonin (PCT), and presepsin (P-SEP) were measured by ELISA. C-reactive protein (CRP), blood urea nitrogen (BUN), serum creatinine, estimated glomerular filtration rate (eGFR), hemoglobin, and neutrophil, lymphocyte, and platelet counts were determined using autoanalyzers. Temporal changes were analyzed using the Friedman test, and correlations were analyzed using Spearman’s test. Results: GDF15 levels began to decrease from Day 3, with a significant decline observed from Day 7 compared to Day 1 (p < 0.001). Similar decreasing trends were observed in CRP and PCT levels, whereas presepsin levels did not exhibit significant changes. Significant positive correlations were identified between GDF15 and CRP (r = 0.65, p = 0.015), BUN (r = 0.57, p = 0.041), and creatinine (r = 0.62, p = 0.024), and a significant negative correlation was observed with eGFR (r = −0.62, p = 0.024). No significant correlation was found between GDF15 and presepsin (p > 0.05). Conclusions: GDF15 is a biomarker sensitive to the resolution phase of inflammation and organ dysfunction in sepsis, demonstrating significant temporal changes. It holds potential as an indicator for monitoring clinical progression and assessing prognosis.
The relationship between agility and vertical jump performance in male handball players: A cross-sectional analysis on the role of developmental characteristics
(Public Library of Science, 2025) Ergin, Rıdvan; Karcı, Betül
Aim This research examines the relationship between agility and vertical jump by controlling for developmental characteristics (age, height, and body weight), which are important for sports performance yet underexplored in literature. Materials and methods In this quantitative research, the study group was determined by power analysis and participants were selected using purposive sampling method. The study group consists of 15 male handball players (age 24.1 ± 5 years) who volunteered to participate. Agility performance was determined by the “Illinois Test”, while jumping performance was assessed by the “Vertical Jump Test”. The Pearson test was used in the relationship analysis as a result of the normality assumption. Additionally, a partial correlation analysis was conducted to control for the effect of developmental characteristics (α = 0.05). Results A positive significant relationship was found between age and years of sports (r = .759; p < 0.01) and vertical jump (r = .657; p < 0.01) in male handball players, as well as a positive significant relationship between body weight and agility (r = .621; p < 0.05). Additionally, while controlling for age (pr = −.557; p = 0.039) and body weight (pr = −.558; p = 0.038), a negative significant relationship was found between agility and vertical jump. Conclusion and suggestions As a result, based on the studies examined, it has been observed that male handball players have a high level of agility and vertical jump performance. At the same time, it has been noted that a decrease in age increases agility performance, while an increase in age enhances jump height. The statistical relationship between agility and vertical jump has only been determined when developmental characteristics are controlled. Therefore, it is suggested that to better clarify the relationship between variables in sports performance research, studies should be conducted with developmental characteristics controlled. Additionally, trainers should train agility and vertical jump, testing athletes regularly at set intervals throughout the season for performance tracking.
