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
Honoring Paris Pişmiş' Legacy: Uniform Astrophysical Properties of 14 Understudied Clusters from Gaia DR3
(IOP Publishing, 2026) Koç, Seliz; Akbaba, Furkan; Plevne, Olcay; Alan, Neslihan
Open clusters are fundamental tracers of the chemical and dynamical evolution of the Galactic disc. This study presents a systematic characterisation of 14 understudied open clusters from the Pismis catalog, selected as those for which the Gaia DR3 data support a well-defined stellar sequence, and spanning a wide range of ages and distances. Utilizing high-precision Gaia DR3 data, we aim to provide a high-fidelity modernisation of these historical discoveries while testing the consistency of our analytical framework across diverse stellar populations. Membership probabilities were determined via the unsupervised UPMASK algorithm using Gaia DR3 astrometric data (positions, proper motions, and parallax). To ensure high sample purity, the member samples entering the isochrone fits were restricted to P >= 0.90, with all subsequent astrophysical parameters calculated through membership-weighted likelihoods. Fundamental properties-including age, distance, reddening, and metallicity-were derived using a Bayesian Nested Sampling approach to isochrone fitting, a methodology chosen for its robustness in navigating the parameter degeneracies typical of dense Galactic fields. The 14 systems exhibit a broad distribution of properties, with ages ranging approximately 11 Myr to 1.5 Gyr and distances spanning approximately 690 to 5445 pc. These refined and uniform parameters reconcile historical observations with the precision era of modern astrophysics, providing an internally homogeneous baseline for systems that large-scale automated surveys recover only partially. A direct cross-match against widely used automated catalogs shows that they typically contain only about a third of the members identified here, and substantially less in the most crowded fields, underscoring the value of cluster-specific analysis. This work contributes to a more complete census of the Galactic disc and sets out a reproducible, per-cluster reliability assessment that can be applied to the many comparable low-latitude systems that remain to be characterised.
Illuminant-dependent color inconstancy and metameric behavior of anodized titanium through silicone-based gingival simulation layers of varying thickness
(Springer, 2026) Çopuroğlu, Akanay; Davut, Umur; Doğanay Özyılmaz, Özge; Özyılmaz, Özgün Yusuf
This in vitro study evaluated how gingival thickness and anodization color affect color perception of Grade V titanium discs under different light sources. Ninety-six titanium discs were anodized yellow, pink, or purple, or left non-anodized. Silicone gingival masks of 1 mm and 2 mm simulated soft tissue. A single spectral reflectance measurement was recorded for each specimen using a benchtop spectrophotometer, from which color coordinates under five standardized illuminants (D65, D50, A, F2, F11) were computationally derived. Color differences (ΔE₀₀) were calculated using the CIEDE2000 formula to evaluate color inconstancy, and metamerism was quantified using a CIEDE2000-based metamerism index (MI), the mean absolute difference between ΔE₀₀ under the test illuminants (D50, A, F2, F11) and D65. Data were analyzed with one-way ANOVA, Tukey HSD post hoc tests, and independent t-tests (α=0.05). All anodized colors at 1 mm exceeded the CIEDE2000 clinical acceptability threshold (ΔE₀₀ >1.8), with purple showing the highest inconstancy, particularly under fluorescent lighting (P<.05). Increasing thickness to 2 mm significantly reduced ΔE₀₀ across all groups (P<.05), although values remained above the acceptability threshold in every group, with purple showing the greatest relative stability under all illuminants. Metameric behavior remained imperceptible under most conditions, except for pink at 1 mm under F2. Thickness and lighting significantly affect color stability of anodized titanium, although the effect of illuminant type was color-dependent: fluorescent (F2) illumination increased color inconstancy for purple and, at 2 mm, yellow, whereas pink showed the opposite pattern, with its lowest ΔE₀₀ values occurring under F2 rather than D65 at both thicknesses. Thinner tissue intensifies color shifts, while≥2 mm thickness improves consistency. Pink performs better in thin tissue; purple shows greatest stability with thicker coverage. Metamerism was imperceptible under most conditions, except for pink at 1 mm under F2, which reached a perceptible but clinically acceptable level.
Retention and Wear Performance of Locator Attachments Under Cyclic Loading: An In Vitro Study
(2026) Dede, Merve; Bozdağ, Ergün; Dayan, Süleyman Çağatay; Ünalan, Fatma
Purpose: The objectives of the current study were to evaluate and compare the retention loss and wear rates of locater attachments made of three different materials under cyclic load. Materials and methods: Three locater attachments, including those made of titanium nitride-coated (conventional Locator), titanium carbon nitride-coated (Locator R-Tx), and zirconia (TAV Locker), were used to produce 42 specimens. Half of the samples in each group were placed straight, while the other half were positioned at the maximum recommended angulation in custom aluminum molds. Each sample was treated to 5,000 insertion-separation cycles. Retention forces were assessed after 10, 500, 1,000, 4,000, and 5,000 insertion-separation cycles. Furthermore, the wear of the attachments was assessed using the mass loss technique and scanning electron microscopy. Results: Although the mean retention values of the angle-placed attachments did not differ significantly across all cycles (p > 0.05), there was a statistically significant difference in the mean retention values of the straight-placed attachments across all cycles. titanium carbon nitride demonstrated higher retention values in each retention test cycle compared to titanium nitride-coated and zirconia locator attachments (p≤0.001). The greatest weight loss among the locator attachments was observed in the titanium carbon nitride-coated angle-placed group (-0,066), while among the nylon inserts, the titanium nitride-coated angle-placed group exhibited the most significant weight loss. (-2,727). Conclusion: The retention force of the titanium carbon nitride-coated group was statistically higher both in straight and angle-placed specimens at the beginning and end of the study compared to the other attachment groups.
Mindful eating as a supportive intervention for breast cancer survivors: a pilot randomized controlled trial
(Springer, 2026) Baş, Dilşat; Ağır, Gizem; Sönmez, Özlem; Önes, Ece
Background Breast cancer (BC) survivors often face weight management and disordered eating challenges that may impair quality of life. This pilot randomized controlled trial evaluated the effects of a six-session mindful eating intervention on eating behaviors and body composition in BC survivors. Methods Breast cancer survivors were enrolled in a pilot randomized clinical trial and randomly assigned to mindful eating intervention plus treatment-as-usual (TAU + MEI, n = 13) or treatment-as-usual alone (TAU, n = 15). Intuitive and mindful eating were assessed using the Intuitive Eating Scale-2 (IES-2) and the Mindful Eating Questionnaire-30 (MEQ-30). Anthropometric measures were assessed monthly over six months. Longitudinal changes were analyzed using repeated-measures ANOVA and generalized estimating equations (GEE). Results Reliance on hunger and satiety cues increased significantly over time in both groups (TAU: p = 0.004; TAU + MEI: p = 0.007). Significant improvements were observed in selected mindful eating dimensions, including disinhibition, emo-tional eating, eating control, and eating with attention and intention (all p < 0.05). MEQ-30 total scores increased significantly in both groups (TAU: p < 0.001; TAU + MEI: p = 0.010). Waist circum-ference decreased significantly in the TAU group (p = 0.002), while hip circumference decreased in the TAU + MEI group (p = 0.009). GEE analysis showed that participation in the TAU + MEI group was independently associated with lower BMI over time (p = 0.013), whereas HR(+)/HER2(-) sub-type and chronic disease were associated with higher BMI (all p < 0.05). Conclusions Both TAU and TAU + MEI were associated with improvements in selected eating-behavior and anthropometric outcomes over time, including indicators of central adiposity, with no clear overall superiority of TAU + MEI across the outcomes assessed. These exploratory findings support further investigation of incorporating mindful eating into standard nutritional care for breast cancer survivors.
Intelligent Periodontics: Integrating Artificial Intelligence and Nanotechnology in Next-Generation Prosthetic Dentistry
(Tehran University of Medical Sciences, 2026) Haghverdi, Fatemeh; Salehi, Nushin; Farokhnia, Hasti; Rouzbahani, Faezeh Gandomi; Chahardoli, Mohammad Reza; Madani, Maryam; Armand, Nafiseh
This review explores how combining artificial intelligence and nanotechnology can reshape periodontics and prosthetic dentistry by enabling more precise, predictive, and personalized care. It first outlines the conceptual foundations of intelligent periodontics, emphasizing data driven decision making, the shift from conventional to digital workflows, and the integration of AI into routine diagnostic and therapeutic processes. The paper then examines current AI applications in periodontal diagnosis, disease progression prediction, and prosthodontic workflows, highlighting improvements in imaging analysis, treatment planning, and prosthesis design. In parallel, it reviews nanotechnology based strategies for periodontal regeneration, implant surface modification, antimicrobial coatings, and targeted drug delivery, focusing on their contribution to enhanced tissue integration and long term clinical performance. The convergence section discusses AI assisted design and optimization of nanomaterials, smart and responsive nano systems, and data driven development of next generation implants and prostheses. Clinical translation challenges including nanotoxicity, data privacy, algorithmic bias, regulatory gaps, cost, and training needs are critically analyzed, alongside future trends such as nanorobotics, AI enabled precision prosthodontics, and IoT based smart oral devices. Overall, the review provides a structured framework for responsibly integrating AI and nanotechnology into modern periodontal and prosthetic practice, aiming to support more effective, safe, and patient centered dental care. © 2026 Tehran University of Medical Sciences. All rights reserved.
