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
Coenzyme Q10 protects against 6 GHz electromagnetic field-induced liver injury via suppression of inflammatory responses associated with NF-κB/p65 immunoreactivity and endoplasmic reticulum stress
(Nature Publishing Group, 2026) Akyıldız, Kerimali; Yılmaz, Hamit; Yılmaz, Adnan; Mercantepe, Tolga; Gül, Fatih; Tümkaya, Levent
We evaluated endoplasmic reticulum stress responses in hepatic tissues following 6 GHz electromagnetic field (EMF) exposure and the protective effects of Coenzyme Q10 (CoQ10). The experimental design included 24 male Sprague-Dawley rats randomly assigned to three groups: (i) sham control group, (ii) 6 GHz EMF exposure group, and (iii) 6 GHz EMF exposure + CoQ10 treatment group. Rats in the exposure groups were subjected to 6 GHz EMF exposure for 2 h/day over 30 consecutive days. Rats in the exposure groups were subjected to 6 GHz EMF exposure (0.21 mW/cm2; specific absorption rate: 0.014 W/kg) for 2 h/day over 30 consecutive days. In addition, the animals in the CoQ10 treatment group received CoQ10 orally at a dose of 10 mg/kg/day throughout the exposure period. After completing the experimental protocol, hepatic tissue samples were obtained for subsequent analyses. Comparative analyses revealed significant differences in TBARS, GSH, TNF-α, IL-1β, ALT, and AST levels across the control-6 GHz and 6 GHz -6 GHz + CoQ10 groups. Exposure to 6 GHz EMF increased histopathological damage and liver histopathological score values, whereas CoQ10 markedly reduced these changes and suppressed glucose-regulated protein 78, C/EBP homologous protein, oxidative 8-hydroxy-2'-deoxyguanosine, and nuclear factor kappa B p65immunoreactivitiesy. 6 GHz EMF induces hepatic dysfunction via oxidative stress, endoplasmic reticulum stress, inflammation, and DNA damage, whereas CoQ10 mitigates these effects of EMF exposure.
Nitrogen and water application differentially influence nutritional value and mineral content in grains of a genetically diverse sorghum germplasm collection
(BioMed Central, 2026) Bedir, Mehmet; Altaf, Muhammad Tanveer; Liaqat, Waqas; Cömertpay, Gönül; Hermans, Christian; Çatalkaya, Volkan; Baloch, Faheem Shehzad
Background: The nutritional profile of sorghum grains, such as antioxidant (AOX) status and mineral content, can be influenced by a number of environmental factors and agricultural practices, as well as by biotic and abiotic stresses. We investigated the impact of contrasting nitrogen (N) and water availability on 15 traits associated with sorghum nutritional value, including AOX capacity (AOX), total phenolics content (TPC), total protein, ash, moisture, and the concentration of 10 macronutrients [nitrogen in leaves (NCL) and grains (NCS), P, K, Mg, Ca] and micronutrients (Fe, Cu, Zn, Mn) in grains. To this end, we evaluated a broad and genetically diverse germplasm collection of 124 accessions over two years of field experiments conducted under optimal N and water availability (control, +N+FC100); under N restriction (-N+FC100); and under N and water restriction (-N+FC50).
Results: Significant effects for treatment, accession, year, and their interactions were found for most traits. In general, N and water restriction treatments were detrimental -as compared to controls- for most traits, as evidenced by decreases in mean values of 10-50% (for -N+FC100) and 8-58% (-N+FC50) consistently found for 11 traits. The most affected variables under -N+FC100 conditions were Zn, Mg, and Cu; and P, Zn, Mg under -N+FC50. In contrast, AOX and TPC levels showed increases in mean values of ~ 11-103% under -N+FC100 and -N+FC50 conditions. These two variables were moderately-to-strongly correlated (r = 0.53-0.96) across all environmental conditions and years, suggesting that phenolic compounds are the main drivers of AOX capacity in sorghum. Results from principal component analysis clearly depicted the strong effects of N-restricted and combined N plus water-restricted conditions on sorghum's nutritional and mineral contents. Genetically-stable accessions with the greatest and lowest performances for each trait and growing condition were selected for breeding purposes.
Conclusions: Nitrogen and water restrictions strongly -yet differentially- influence nutritional and mineral contents in sorghum, enhancing TPC and AOX while reducing mineral levels. This study characterized a large germplasm collection across various growing conditions and years, facilitating the selection of resilient genotypes for breeding programs aimed at improving nutritional value under changing climatic conditions.
Effect of CXCR5, PD-1 and ICOS on B-cell responses and relevance to myasthenia gravis
(Nature Publishing Grou, 2026) Çebi, Merve; Çakar, Arman; Durmuş, Hacer; Parman, Yeşil
Objectives: T follicular helper (Tfh) cells regulate B-cell responses within germinal centres primarily via programmed cell death protein 1 (PD-1) and inducible T-cell costimulator (ICOS), whereas CXC chemokine receptor type 5 (CXCR5)-negative T peripheral helper (Tph) cells provide similar support extra-follicularly. Both subsets contribute to the pathogenesis of acetylcholine receptor-antibody-positive myasthenia gravis (AChR-MG). This study investigated the roles of PD-1, ICOS and CXCR5 in T-cell-mediated B-cell activation to identify therapeutic targets for MG.
Methods: CD4 T cells from 10 healthy controls and six untreated AChR-MG patients were sorted by CXCR5, PD-1 and ICOS expression, stimulated with anti-CD3/CD28, and co-cultured with autologous CD19 B cells. Plasmablast differentiation, total AChR-IgG and cytokine productions were measured.
Results: In healthy donors, PD-1+ or ICOS+ Tph cells modestly enhanced plasmablasts and IgG production, while CXCR5+ Tfh cells co-expressing PD-1 or ICOS induced significantly stronger B-cell responses. In AChR-MG patients, PD-1 expressing T cells promoted plasmablasts, antibody production and cytokine secretion regardless of CXCR5, with amplified effects in CXCR5+ co-cultures.
Conclusions: PD-1 expression on CD4+ T cells is associated with increased B-cell helper capacity. This effect is more pronounced in Tfh-related contexts and is linked to dysregulated humoral immune responses in MG. PD-1 appears to play a central role in the pathogenesis of MG, primarily through Tfh cell activity.
Pressure-dependent structural, mechanical, and electronic properties of XAu (X = Er, Tm) intermetallic compounds from first-principles calculations
(Nature Publishing Group, 2026) Benmakhlouf, A.; Mezouar, R.; Daoud, S.; Ghebouli, M.A.; Fatmi, M.; Bouferrache, K.; Yaylacı, Murat
First-principles calculations of the structural parameters, elastic constants, mechanical moduli, Debye temperature, and density of states (DOS) of cubic CsCl-type (B2) XAu (X = Er, Tm) rare-earth intermetallic compounds under hydrostatic compression up to 20 GPa have been performed. The calculations were carried out within the framework of density functional theory (DFT) using the pseudopotential plane-wave (PP-PW) method and the local density approximation (LDA). The calculated elastic constants indicate that both ErAu and TmAu with the CsCl-type (B2) phase satisfy the Born mechanical stability criteria at equilibrium and under pressure up to 20 GPa for ErAu and up to about 19 GPa for TmAu. The zero-pressure structural parameters, elastic constants, and mechanical moduli are generally in good agreement with previously reported theoretical data. The calculated zero-pressure Young's modulus values are 96.61 GPa for ErAu and 73.94 GPa for TmAu, while the corresponding Debye temperatures are 193 K and 167 K, respectively. The obtained results reveal that hydrostatic pressure enhances the stiffness of both compounds, as reflected by the general increase in the elastic constants, acoustic wave velocities, and Debye temperature. Both ErAu and TmAu exhibit ductile behavior according to Pugh's ratio and show noticeable elastic anisotropy. The electronic-structure analysis confirms the metallic character of both compounds, while additional GGA + U calculations indicate that the localized 4f states are sensitive to the Hubbard correction without changing their metallic nature. The pressure-dependent elastic constants and related mechanical and thermodynamic properties of XAu (X = Er, Tm) intermetallic compounds have not been previously reported; therefore, the present results provide useful predictions and reference data for future theoretical and experimental studies.
Posttraumatic growth in mothers of children with special needs: exploring experiences in Türkiye
(BioMed Central, 2026) Yazıcı Kabadayı, Sema; Gülar, Alper
Background: This study aimed to explore in detail the posttraumatic growth (PTG) experiences of mothers of children with special needs (MCWSN). Exploring the perspectives of these mothers is crucial for evaluating family support programs, identifying supportive resources, and developing innovative interventions.
Methods: A qualitative phenomenological design was employed to gain a deep understanding of mothers' lived experiences. Participants were selected through purposive sampling, and interviews were recorded using a semi-structured interview guide designed by the researchers to align with the study's purpose. Face-to-face interviews were conducted between November 2023 and January 2024 in two different provinces of Türkiye, where 23 MCWSNs were interviewed.
Results: Thematic analysis revealed three main themes: (1) a positive approach to life, (2) communication and social engagement, and (3) personal growth and inner strength. Findings showed that having a child with special needs creates positive relational changes in mothers, leading to personal growth and the discovery of inner strength. It has also contributed to mothers' positive approach to life.
Conclusions: These results provide valuable insights for social policymakers, special education teachers, counselors, and families, highlighting the potential integration of PTG into family support programs and psychosocial interventions. Such initiatives could help MCWSNs effectively adapt to societal and workforce challenges.
