İstanbul Sağlık ve Teknoloji Üniversitesi Kurumsal Akademik Arşivi
DSpace@İSTÜN, Üniversite mensupları 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
Protective effects of royal jelly in diabetic rat testis tissue through apoptotic and antiapoptotic pathways
(Aves, 2026) Ersoy, Onur; Delen, Özlem; Yavaş, Şirin; Bayram, Şinasi; Kızılay, Gülnur
Objective: Diabetic male subfertility and/or infertility represents an area of research that has attracted attention and therefore become a subject of investigation at the molecular level. The insulin-like effects, antihypertensive, antitumor, antioxidative, anti-inflammatory, and immunomodulatory roles of royal jelly (RJ) have been demonstrated by scientific research. This study was designed based on the hypothesis that RJ may have the potential to prevent apoptosis in testicular tissue and, consequently, exert a beneficial impact on spermatogenesis through its ability to mitigate the adverse effects of diabetes on testicular tissue. The aim is to identify some of the molecular factors that may be responsible for the therapeutic effects of RJ on diabetic testicular tissue. Methods: Apoptosis, proliferation, and Leydig cell functions were determined using the following markers: transferase dUTP nick end labeling analysis, c-Jun N-terminal kinase (JNK), p38, Fas, and FasL for apoptosis; proliferating cell nuclear antigen (PCNA) and extracellular signal-regulated kinase (ERK) for proliferation; and insulin-like peptide-3 (INSL3) for Leydig cell function. A total of 20 Wistar albino male rats were randomly assigned to 3 experimental groups. The control group (C) and the diabetic group (D) were administered a single dose of 50 mg/kg STZ (intraperitoneally), and the RJ group was given 400 mg/kg/day (ig.) RJ after a single dose of 50 mg/kg STZ. Results: While PCNA, ERK, and INSL3 immunoreactivities were significantly increased, the apoptotic cell and tubule indices, JNK, p38, Fas, and FasL immunoreactivities were significantly decreased in the RJ group compared to the D group. Conclusion: Royal jelly may have a protective effect in preventing diabetes-related male infertility through apoptosis and anti-apoptotic pathways.
Photoinactivation of MRSA AТCC 33591 by antimicrobial photodynamic therapy using coumarin-functionalized zinc(II) phthalocyanine
(Slovensko Kemijsko Drustvo, 2026) Bilgin, Merve; Elgün, Tuğba; Aktaş, Çiğdem; Karagülle, Onur Olgaç; Çınar, Kamil; Gök Yurttaş, Asiye
This study evaluates the photodynamic inactivation potential of a coumarin-functionalized zinc(II) phthalocyanine derivative against methicillin-resistant Staphylococcus aureus (MRSA) AТСC 33591. The antimicrobial and cytotoxic effects of the derivative were assessed under dark and laser-irradiated (658 nm) conditions. Minimum inhibitory concentration (MIC) values were determined, and the photodynamic response was further explored in MRSA-infected HT-29 (human colorectal adenocarcinoma) and HUVEC (human umbilical vein endothelial) cell models. While the derivative exhibited dose-dependent antibacterial activity, the light-induced reduction in colony-forming units (CFU) was moderate, remaining below a tenfold (1-log10) under the tested conditions. In cell-based assays, the compound showed detectable dark cytotoxicity,which was further enhanced upon laser irradiation. The photodynamic cytotoxic response was more pronounced in infected HT-29 cells than in infected HUVEC cells, with flow-cytometric profiles consistent with predominantly necrotic/late apoptotic cell-death patterns. These findings indicate that the compound exhibits light-enhanced effects in complex infection models; however, further optimization offormulation, photophysical properties, and light dosimetry is required to improve antimicrobial efficacy and selectivity.
Poly(bromophenol blue)/ CoSn(OH)6 cubic particles modified pencil graphite electrode for electrochemical determination of diphenhydramine
(Nature Research, 2026) Karakaya, Serkan; Bakırdere, Sezgin; Şaylan, Meltem; Dilgin, Yusuf
In this study, a poly(bromophenol blue) (poly(BPB))-coated CoSn(OH)6 cubic particles -modified pencil graphite electrode (poly(BPB)@CoSn(OH)6/PGE) was developed, and its electrochemical activity towards diphenhydramine (DPHN) oxidation was systematically investigated. Cyclic voltammetric studies revealed that the oxidation of DPHN at the modified electrode is governed by a diffusioncontrolled process, indicating strong interaction between DPHN molecules and the poly(BPB) film. The incorporation of the CoSn(OH)6 cubic structure enhances electron transfer kinetics by increasing the density of electroactive sites and facilitating charge transport across the electrode interface. This cooperative interaction between the conductive polymer and metal hydroxide structure results in a significant amplification of the oxidation response. Under optimized conditions, the proposed electrode exhibited a linear response in the concentration range of 1.0–500.0 µM with a detection limit (LOD) of 0.30 µM. Although the analytical performance is comparable to previously reported systems, the present work provides deeper insight into the role of polymer–metal hydroxide interfaces in governing electrochemical sensing behavior. The sensor also demonstrated acceptable selectivity and applicability in pharmaceutical, biological, and environmental samples. These findings highlight the importance of interfacial design in improving electrochemical performance and offer a useful framework for developing advanced hybrid sensing platforms.
Production-phase carbon footprint of photopolymer resin workflows for direct-print orthodontic aligners: A screening carbon-footprint assessment
(MDPI Publishing, 2026) Özcan, Mustafa; Allaf, Ferdi
Direct-print aligners are widely presented as the environmentally preferable alternative to thermoforming, but which part of the process governs the carbon released during manufacture has not been established. Four commercial printer–resin workflows were modelled: Graphy Tera Harz resin on a Uniz NBEE (A) and an Asiga MAX 2 (B), the LuxCreo iLux Pro as a closed chain (C), and Graphy resin on a DentaFab Sega Pro (D). Energy, material and throughput data came from the manufacturers. Production-phase CO2e per aligner was propagated through 10,000 Monte Carlo draws, with the resin emission factor sampled across its full published range (3.0–6.5 kg CO2e/kg) and the thermoformed comparator represented as a distribution. Mean footprints were 0.043, 0.036, 0.089 and 0.020 kg CO2e per aligner (95% uncertainty intervals were 0.032–0.056, 0.026–0.047, 0.077–0.101 and 0.016–0.025), against a thermoformed median of 0.190. Direct printing was the lower of the two in every paired iteration. Resin dominated, contributing 41–79% of the total; solvent added a further 41% in the one workflow using it, while electricity of all kinds accounted for 19–36%. Thermoforming would match direct printing only at series lengths of 45 to 202 aligners, far above the 14–30 of clinical practice; under the most unfavourable resin factor the margin narrowed but did not close. Material efficiency, not energy sourcing, is where reductions are available.
Biocompatibility of five occlusal splint materials produced by four fabrication methods: An in vitro comparative study
(Springer Nature Link, 2026) Atay, Ayşe; Ayvalıoğlu Şamiloğlu, Demet Çağıl; Yıldırım, Zafer; Bozok, Vildan; Gökçen Rohlig, Bilge; Karabece, Ebru; Sevük, Çetin
Background To evaluate the cytotoxicity, cell death, interleukin-6 (IL-6) release, and surface roughness of five occlusal splint materials produced by four different fabrication methods on L929 mouse fibroblasts. Methods 240 disc-shaped specimens (15×2 mm) were fabricated from milled polymethyl methacrylate (PMMA), milled polyetheretherketone (PEEK), 3D-printed photopolymer resin, thermoformed polyethylene terephthalate glycol (PET-G), and auto-polymerizing PMMA. Extracts were prepared following ISO 10993-12 and collected on days 1, 3, and 7; at each time point the extracts of four specimens were pooled and applied to three replicate wells. Cell viability (XTT), total cell death (Annexin V-FITC/PI flow cytometry), IL-6 release (ELISA), and surface roughness (Ra, contact profilometer) were assessed. As the replicate wells were technical replicates of a single pooled extract, the biological data are reported descriptively; surface roughness was analyzed by one-way ANOVA with Tukey’s HSD test (p<0.05). Results On day 7, the auto-polymerizing PMMA group showed the lowest cell viability (68.44±3.48%) and was the only material to fall below the 70% threshold of ISO 10993-5. Cell viability remained above the 70% threshold in all other groups at all time points. Total cell death was low throughout (1.40–3.20%; untreated control 1.50%), with the highest day-7 values in the thermoformed PET-G (3.20±0.30%) and auto-polymerizing PMMA (3.07±0.86%) groups. IL-6 was below the limit of detection (18.75 pg/mL) in most conditions; only the autopolymerizing PMMA group on day 7 yielded quantifiable IL-6, in two of three wells (33.78 and 42.55 pg/mL). The milled-PEEK and thermoformed PET-G groups showed the lowest Ra values, whereas the milled-PMMA group showed the highest (p=0.005). Conclusions In this in vitro extract model, the auto-polymerizing PMMA group was the only material falling below the 70% viability limit of ISO 10993-5 and the only one with quantifiable IL-6 on day 7. All other groups remained above this threshold throughout, and total cell death remained low in all groups. The milled and printed materials evaluated in the present study may therefore represent biologically more favorable options than the auto-polymerizing PMMA group. These findings are descriptive, based on a single pooled extract per condition, and apply only to the specific products tested.
