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
Magmatic fertility in post-collisional arcs: contrasting juvenile mafic intrusions and Cu-Mo fertile felsic systems in the Eastern Sakarya Zone (NE Türkiye)
(Elsevier, 2026) Moghadam, Hadi Shafaii; Xiao, Wenjiao; Özen, Sevgi; Mao, Qigui; Miao, Sang
The Eastern Sakarya Zone (ESZ) of northeastern T & uuml;rkiye records a remarkable duality in Eocene magmatism, where Cu-Mo fertile felsic porphyries coexist with barren mafic-intermediate intrusions. We present an integrated, multi-proxy investigation of the I(center dot)spir intrusive complex, incorporating whole-rock geochemistry, zircon U-Pb-Hf isotope-trace element systematics, and apatite major-trace element and in-situ Nd isotopic signatures, to delineate the petrogenetic pathways and magmatic processes that control fertility contrasts across this intrusive suite. Zircon and apatite proxies reveal that I(center dot)spir magmas were derived from a juvenile mantle source, retained consistently radiogenic isotopic signatures, and crystallized under relatively reduced, volatile-poor conditions. In contrast, fertile Eocene felsic intrusions in the ESZ show enriched isotopic signatures, elevated oxidation states, and volatile-rich magmas derived from a metasomatized mantle source and buffered in longlived crustal magma reservoirs, conditions favorable for porphyry Cu-Mo fertility. Apatite-derived estimates of Cl, F, S, and Delta FMQ further distinguish these suites, with fertile magmas showing elevated halogens and sulphur contents coupled with oxidized states favorable for delayed sulphide saturation and metal transport. These results demonstrate that in post-collisional arcs, fertility depends not only on tectonic triggers such as slab break-off or lithospheric delamination but also on whether melts are processed through volatile-charged, oxidized hot zones. The I(center dot)spir suite provides a critical juvenile end-member against which fertile felsic counterparts can be contrasted, offering a refined framework to assess magmatic fertility across the Tethyan Metallogenic Belt and other collisional orogens.
Ameliorative effect of boric acid on acute cadmium-induced oxidative stress, inflammation, histopathological injury and proapoptotic changes in rat liver
(Çukurova Üniversitesi, 2026) Akpulat, Faik Veysel; Akkuş, Murat; Yıldızhan, Eda; Aba, Murat; Bolat, Levent; Aday, Ulaş
Purpose: This study aims to investigate the ameliorative effects of boric acid (BA) on cadmium (Cd)-induced hepatotoxicity were investigated in rats. Materials and Methods: Twenty-eight male Wistar albino rats were randomly assigned to four groups (n=7 each): Control; Cd (single oral dose of Cd 15 mg/kg by gavage, no further treatment for 7 days); BA (boric acid 200 mg/kg/day intraperitoneally for 7 days); and Cd+BA (combined cadmium and boric acid). Serum malondialdehyde (MDA) and total oxidant status (TOS) were measured to assess oxidative stress. Results: MDA and TOS levels were highest in the Cd group compared with the other groups, while these levels were reduced in the Cd+BA group. AST levels were significantly elevated in the Cd group (194.42 U/L) compared with the Cd+BA group (110.57 U/L). Similarly, LDH levels were significantly lower in the Cd+BA group. Histopathological evaluation of liver tissues showed markedly higher damage scores in the Cd group, whereas inflammatory and proapoptotic changes were less pronounced in the Cd+BA group. Conclusion: These findings suggest that BA administration after acute Cd exposure may reduce hepatic injury by lowering oxidative stress, inflammation, and apoptosis.
Stress distribution of inlay, onlay, and overlay restorations across materials: A finite element study
(JAPAN PROSTHODONTIC SOC, 2026) Kurt, Sedef; Yeşil, Zeynep
Purpose: We evaluated the stress distribution patterns in inlay, onlay, and overlay restorations fabricated from different CAD-CAM materials, including current 3D-printed resins and 3D-printed zirconia, under 300 N vertical loading using finite Methods: A 3D solid model of a mandibular first molar was generated based on standard anatomical dimensions. Fifteen finite element models were constructed by combining three preparation designs with five restorative materials. A static vertical load of 300 N was applied and distributed across the multipoint occlusal contacts to simulate physiological masticatory forces. The stress distribution was analyzed using the von Mises and Maximum Principal Stress criteria to evaluate both the restoration and the surrounding dental tissues. Results: Restoration design and material stiffness significantly influenced stress distribution. Among the designs, the overlay preparations exhibited the most favorable biomechanical behavior, showing lower stress transmission to the tooth structure than inlay and onlay designs. Materials with a high elastic modulus (205.000 MPa LithaCon 3Y-210) demonstrated a stress-shielding effect, absorbing higher internal stress while protecting the underlying dentin. Conversely, low-modulus materials (4.030 MPa VarseoSmile Crown Plus) exhibited lower internal stress, but transferred higher stress loads to the tooth-restoration interface and dentin. Conclusions: The use of overlay designs combined with high-elastic modulus materials offers a biomechanically superior configuration for reinforcing compromised posterior teeth because this combination minimizes stress transmission to the remaining tooth structure. Although low-modulus materials reduce internal restoration stress, they require careful consideration because of the increased stress transfer to the dentin.
Polycyclic aromatic hydrocarbons (PAHs) in potato and corn chips: Assessment of dietary exposure and health risk
(Elsevier, 2026) Kartal, İdeal Bera Yılmaz; Kırkyol, Mine; Oral, Zeynep Feyza Yılmaz; Akköse, Ahmet; Kaban, Güzin; Kaya, Mükerrem; Başaran, Burhan
Polycyclic aromatic hydrocarbons (PAHs) are toxic, carcinogenic compounds formed during food processing at high temperatures. This study analysed 16 priority PAHs in 31 commercial chip samples (18 corn and 13 potato) and evaluated dietary exposure and associated health risks. Most PAHs were detected, and benzo[a]pyrene, recognized as the most carcinogenic and a key marker of contamination, was showed the highest concentrations (1.07 +/- 0.78 & micro;g/kg in corn and 1.08 +/- 0.55 & micro;g/kg in potato). Total PAHs (E4, E8, E16) were consistently higher in potato chips, with average concentrations of 1.59, 2.63 and 4.27 & micro;g/kg, respectively. Chronic daily intake (CDI) and hazard index (HI) were below safety limits, and incremental lifetime cancer risk (ILCR) was acceptable under low and moderate consumption. Margin of exposure (MOE) values remained above 10,000 in all cases, indicating no significant carcinogenic concern. However, ILCR exceeded 1.0 & times; 10-5 at 100 g/day, highlighting consumption as a key risk factor. Thus, optimising frying conditions could further reduce exposure.
Chitosan nanoparticles induced germination and auxin-related gene regulations in cotton (Gossypium hirsutum L.) using random forest-based multi-output regression analysis
(Elsevier, 2026) Altaf, Muhammad Tanveer; Aasim, Muhammad; Mustafa, Zemran; Ali, Seyid Amjad
Chitosan nanoparticles (CNPs) are emerging nanobiostimulant known to enhance germination, stress tolerance, and hormonal regulation in plants, yet their role in auxin-related gene regulation in cotton remains unexplored. In this study, cotton seeds were exposed to varying concentrations of CNP (0-2.5 mg/L) under in vitro conditions. Seed germination was counted daily for a continuous 21-day period, followed by analysis using the GerminaR statistical package to generate various germination metrics. The germination metrics were analyzed by Random Forest-based multi-output regression analysis. Auxin-related gene expression profiling of ARF, AUX, and UGT was performed at two different concentrations and two time points, using qPCR normalized to His3. Taguchi design (TD) was employed for analyzing gene expressions to quantify factor significance and noise robustness through the S/N ratio. Results revealed maximum germination percentage (GRP) at 1.0 mg/L CNP. Concentrations above 1.5 mg/L CNP negatively impacted germination kinetics with increased germination speed (GSP) and coefficient of variation in germination (CVG). The multi-output regression analysis revealed the highest predictive performance for variance in germination time (VGT) with an R2 score of 0.785, followed by 0.746 for the CVG. Gene expression profiling revealed significant upregulation of ARF and AUX genes with increasing concentration and time. Whereas UGT regulation was dependent on both time and concentration, with variable impact. The TD analysis identified concentration as most significant for ARF regulation, while time was significant for AUX and UGT expressions, confirming the role of CNPs as a bio-stimulant.
