İstanbul Galata Üniversitesi Kurumsal Akademik Arşivi
DSpace@Galata, İstanbul Galata 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 telif haklarına uygun olarak Açık Erişime sunar.
Güncel Gönderiler
Effect of solvent use on dentin crack in retreatment
(2024) Zümrütel, Pelin; Haznedaroğlu, Faruk; Keleş, Ali; Basmacı, Gülsüm Kutlu
AIM or PURPOSE: The aim of this study was to evaluate the effect of solvent use on dentinal crack formation in during root canal retreatment with micro-CT. MATERIALS and METHOD: Root canal treatments were performed on the mesial roots of 20 mandibular molars. The teeth were divided in two groups: Group A: solvent and Group B: Non-solvent. During primary treatment, canal preparation was performed using Revo-S files. The root canals were filled using the lateral compaction technique and AH Plus sealer. During retreatment procedure, Protaper Retreatment Files were used in both groups. Guttasolv was used as solvent during retreatment in group A. Before and after the initial treatment and retreatment, the teeth were imaged using microCT. Meanwhile, the remaining root canal filling materials in the teeth were also examined. RESULTS: Crack formation was not observed in either group. Residual filling material remained in the root canal after the procedure in both groups and there was no statistical significant difference found in terms of residual matter between the regions according to the results of the measurements made separately in three regions as coronal, middle, and apical regions. CONCLUSION(S): In conclusion, within the limitations of this in vitro study, it could be said that Ni-Ti systems do not cause dentin defects if used with or without a solvent. Even if the retreatment was performed close to ideal, it was determined that residual filling material remained on the canal walls during retreatment.
Qraypen In Residual Caries Detection And Cavity Disinfection
(2025) Bittar, Ahmad; Alkan, Elif; Tağtekin, Dilek
Introduction: Residual bacterial activity after selective caries removal may compromise restoration longevity. QrayPen, a fluorescence-based device, enables real-time detection of red fluorescence (DR) and maximum red fluorescence (DRmax)— markers of bacterial activity. This case series explores QrayPen’s utility in identifying residual caries and evaluating the antibacterial effect of 2% chlorhexidine digluconate applied as a cavity disinfectant. Case description: Five adult patients with active dentinal caries underwent selective caries removal. QrayPen was used to measure DR and DRmax before and after chlorhexidine application. Measurements were standardized in a dark environment with consistent drying and probe positioning. Lesions were also evaluated using ICDAS II, Nyvad criteria, and ICCMS radiographic scores. All five cases showed detectable fluorescence post-caries removal; post-disinfection readings indicated reduced bacterial activity. Discussion: The findings suggest QrayPen can identify residual bacterial presence undetectable by conventional visualtactile methods. The observed decrease in DR and DRmax values after chlorhexidine application supports its effectiveness as an adjunctive diagnostic tool. This dual use may enhance decision-making in minimally invasive restorative protocols by confirming both cleanliness of the cavity and efficacy of disinfection. Conclusion/clinical significance: QrayPen may aid clinicians in verifying caries removal and evaluating cavity disinfection in real time. Its integration into routine practice could support more conservative and evidence-based restorative treatments, improving long-term outcomes.
Mitochondrial Dynamics‑Related Gene Regulation by Epigenetic Suppression of GCN5 Exerts Neuroprotective Effects in Rotenone‑Induced Parkinson’s Disease Model
(2026) Kuşçu, Gökçe Ceren; Tut, Ezgi; Gürel, Çevik; Buhur, Aylin; Germiyan, Özgün Selim; Avcı, Çığır Biray; Güler, Cem; Şancı, Ebru; Yavaşoğlu, Nefise Ülkü Karabay; Yavaşoğlu, Altuğ
Parkinson’s disease (PD) is a progressive neurodegenerative disorder characterized by dopaminergic neuron loss and mitochondrial dysfunction. Recent studies implicate the histone acetyltransferase GCN5 in regulating mitochondrial homeostasis and oxidative stress. This study investigated the therapeutic potential of GCN5 silencing via systemically administered siRNA-loaded niosomes in a rotenone-induced rat model of PD. Niosomes were prepared using the thin-film hydration method, and the most effective siRNA sequence was selected through real time quantitative PCR (RT-qPCR) and immunofluorescence in primary mesencephalic neurons. Adult male rats were divided into four groups (n=24/group), and PD was induced with rotenone (2 mg/kg/day, s.c., for 35 days). Behavioral assessments, biochemical analyses, IVIS imaging, histopathology, immunohistochemistry, and RT-qPCR were conducted. IVIS confirmed brain accumulation of siRNA– niosomes within 3–5 h post-injection. GCN5 siRNA treatment significantly improved locomotor activity (p<0.05), decreased MDA levels (p<0.05), and restored SOD and dopamine levels (p<0.05). Molecular findings showed decreased GCN5 and mitochondrial fission-related gene Drp-1 expression, increased expression of mitophagy and biogenesis markers (↑Parkin, ↑PINK1, ↑Mfn2, ↑PGC-1α), elevated TH expression, and reduced α-synuclein accumulation. Histological analysis revealed preserved midbrain cytoarchitecture and reduced neuronal damage. In conclusion, these findings highlight that epigenetic silencing of GCN5 via siRNA-loaded niosomal delivery provides neuroprotection in PD by modulating the expression of genes involved in mitochondrial dynamics, offering preclinical support for its development as a novel therapeutic strategy.
Linking Extended Business Responsibility to Sustainable Environmental Awareness: Evidence on the Mediating Role of Environmental Values
(Wiley, 2025) Avunduk, Zehra Binnur; Kahveci, Eyüp; Habip, Elif
Eco-conscious businesses are increasingly adopting sustainable materials and improving production efficiency to reduce carbon emissions. These efforts not only minimize waste but also help conserve natural resources. Through extended business responsibility (EBR), firms actively promote sustainable consumption by raising consumer awareness. As awareness grows, purchasing behavior shifts toward environmentally responsible choices, ultimately reducing ecological harm. In contexts where environmental values (EVs) are prominent, social pressure often drives firms toward more sustainable practices. This study addresses a gap in the literature by examining the mediating role of EVs in the relationship between EBR and sustainable environmental awareness (SEA). Based on survey data from 396 participants in Türkiye, partial least squares structural equation modeling (PLS-SEM) was employed for analysis. The findings reveal that EVs partially mediate the relationship between EBR and SEA, serving as a catalyst that enhances the effect of EBR on sustainability awareness. The results provide valuable insights for a wide range of businesses, including manufacturers and e-commerce firms. By aligning with the expectations of environmentally conscious consumers, companies can not only strengthen their sustainability agendas but also gain a sustainable competitive advantage. This study contributes to the literature on sustainable business practices by applying PLS-SEM in the context of an emerging economy and highlighting the critical role of EVs in fostering sustainability awareness.
Analysis of Ergonomic Parameters in Architectural Design Studios: A Case Study of Bursa Technical University
(2025) Battal, İmran Gümüş; Köse, İstem Seçkin Parlakyıldız
Ergonomics encompasses physical, psychological, and environmental factors, with a crucial role in educational settings. Design studios, integral to architecture, interior architecture, and urban planning education, must ensure optimal spatial, visual, auditory, and thermal comfort to foster creativity and technical skills. This study evaluates the design studios at Bursa Technical University’s Faculty of Architecture and Design, assessing ergonomic conditions through technical measurements and user satisfaction surveys. Findings reveal that repurposed spaces used as design studios fail to meet essential ergonomic standards, impacting students’ learning experiences. The study highlights deficiencies in spatial organization, lighting, acoustics, and thermal conditions, emphasizing the need for improvements. By addressing these shortcomings, the research aims to guide the optimization of design studios as dynamic educational environments supporting technical drawing, group critiques, model-making, and workshop activities. The study is expected to serve as a guiding reference for the organization of design studios in accordance with ergonomic standards.
