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
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.
Integrated iron foliar application and phosphorus fertilization enhance yield and nutrient dynamics of mung bean in calcareous soils
(BioMed Central, 2026) Khan, Maaz; Ali, Mehran; Ahmad, Haris; Soury, Sher Shah; Altaf, Muhammad Tanveer; Liaqat, Waqas; Aasim, Muhammad
Background: Mung bean production in calcareous soils is often constrained by low nutrient availability, particularly iron (Fe) and phosphorus (P), which limit plant growth and yield. This study aimed to evaluate the effects of Fe foliar application and P fertilization on growth, yield, and nutrient dynamics of mung bean under calcareous soil conditions.
Results: A two-year field experiment (2022-2023) was conducted using a randomized complete block design with Fe foliar application (0, 0.2, 0.4, and 0.6%) and P fertilization rates (0, 30, 60 and 90 kg ha- 1). Iron and phosphorus applications significantly influenced yield components, physiological traits and nutrient accumulation. Foliar application of 0.4% Fe resulted in the highest thousand seed weight (39.42 g), biological yield (3132 kg ha- 1), seed yield (790 kg ha- 1) and crop growth rate (13.58 g m- 2 day- 1), representing increases of 12.21%, 12.54%, 23.44% and 44.47%, respectively over the control treatment. Similarly, phosphorus application at 60 kg ha- 1 significantly enhanced thousand seed weight (39.83 g), biological yield (3156 kg ha- 1) and seed yield (796 kg ha- 1), chlorophyll content (3.12 mg g- 1) and crop growth rate (13.48 g m- 2 day- 1) with increase of 14.49%, 14.06%, 32.89% and 26.22%, respectively compared with the unfertilized control. Seed and straw N (3.58% and 1.27%) and Fe concentrations (36.2 mg kg- 1 and 315 mg kg- 1) were highest under 0.6% Fe, while in case of phosphorus, the plots with 90 kg P ha- 1 produced the maximum seed and straw N (3.97% and 1.06%). The highest seed and straw P concentration (0.31% and 0.16%) was observed at 0% Fe, while application of 90 kg P ha- 1 also enhanced seed and straw P content (0.38% and 0.20%). Agronomic phosphorus efficiency peaked at 30 kg P ha- 1 (4.26 kg kg- 1) and 0.4% Fe (4.29 kg kg- 1), while total N uptake (41.51 kg ha- 1), seed carbohydrate content (62.79%) and soil P (7.02 mg kg- 1) were highest with application of 90 kg P ha- 1. The foliar spray of 0.6% Fe resulted in higher total N uptake (40.45 kg ha- 1), seed carbohydrate content (61.19%) and soil P (6.79 mg kg- 1). Economic analysis revealed that the combined application of 0.4% Fe and 60 kg P ha- 1 produced the highest value cost ratio.
Conclusion: The combined application of 0.4% Fe and 60 kg P ha- 1 is recommended for farmers to enhance mung bean yield and profitability under calcareous soil conditions, where Fe and P availability is often limited, whereas 0.6% Fe with 90 kg P ha- 1 is more effective for enhancing nutrient accumulation. This nutrient management strategy can be effectively adopted under field conditions to improve productivity and nutrient use efficiency.
Genome-wide identification and characterization of 1-amino-cyclopropane-1- carboxylate synthase (ACS) gene family in Carica papaya and expression insights in response to hormone stress
(BioMed Central, 2026) Mudasar Muhammad; Nabi, Hafiz Ghulam; Ahmad, Arsalan; Shafiq, Muhammad; Liaqat, Waqas; Akbulut, Mustafa; Altaf, Muhammad Tanveer
ACC-synthase (1-aminocyclopropane-1-carboxylate synthase), also known as the ACS gene, plays a pivotal role in ethylene production, which is of great importance in the fruit ripening process for producing saleable yield (marketable fruit). The ACS gene family presumably controls stress responses, plant growth and development, and particularly fruit ripening. Computational biology was used as an essential tool to identify seven ACS genes in Carica papaya (red hermaphrodite) using an RNA-seq database (NCBI GEO). Further, the phylogenetic relationships of ACS genes determined gene family resemblance in the genomes of Hordeum vulgare, Musa acuminata, C. papaya, and Arabidopsis thaliana; therefore, the identified gene families were further classified into four distinct clades (Type-I, Type-II, Type-III, and Type-IV) in alignment with the well-established Arabidopsis classification. Moreover, encompassing gene structure, domain motifs, cis-element phylogenetic profiling, synteny, and transcriptomic profiling unveiled latent structural and functional attributes within CpACS genes. Through segmental duplication of CpACS, insights into evolutionary duplication events were predicted. The paralogous behavior of ACS genes in C. papaya and a comprehensive transcriptomic analysis demonstrated both up- and down-regulation patterns in response to ethylene treatment at different time points during the fruit ripening process, using the papaya manual handbook V2 (2021). Gene expression showed upregulation of two essential CpACS genes, CpACS5 and CpACS6. RT-qPCR validates the expression of these important genes during fruit ripening. However, one gene, CpACS7, is expressed in the later stages of fruit development. Our results demonstrated novel avenues for understanding the expression pathways of the ACS gene family in red hermaphrodite papaya, and most of these genes were linked to regulating various abiotic stresses, plant growth, and fruit development.
