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
Structural and functional impact of lingual frenulum alterations on oral and craniofacial development in children during the mixed dentition stage
(Springer Nature Link, 2026) Vural, Yasemin; Esentürk, Gülce; Önder, Ömer Önder; Cebeci, Nesrin; Özen, Buğra
Background The clinical relevance of ankyloglossia in children remains controversial, largely due to the absence of standardized diagnostic criteria and the predominant reliance on morphological assessment. Evidence linking the combined anatomical and functional characteristics of the lingual frenulum to objective functional outcomes during mixed dentition remains limited. Therefore, this study aimed to evaluate the association between lingual frenulum characteristics and oral and craniofacial functional outcomes in children during the mixed dentition period. Methods In this cross-sectional study, 170 children aged 7–12 years were evaluated. Anatomical and functional characteristics of the lingual frenulum were assessed using the Marchesan Lingual Frenulum Protocol. Oro facial functions, including breathing pattern, mentalis muscle activity, and swallowing, were examined using selected components of the Orofacial Myofunctional Evaluation with Scores (OMES/OMES-E). Upper airway patency was evaluated using the Mallampati and Brodsky classifications, malocclusion was assessed clinically, and postural alignment was analyzed using the New York Posture Scale. Intergroup comparisons were performed (p < 0.05). Multivariate logistic regression analyses were conducted to identify independent predictors of swal lowing dysfunction. Results Maximum mouth opening did not differ significantly between groups (p = 0.137). However, reduced tongue range of motion (≤ 50%) was significantly more frequent in children with an altered frenulum (p < 0.001). No significant differences were observed in respiratory pattern, mentalis muscle activity, Mallampati or Brodsky scores (p > 0.05). Swallowing-related dysfunction, involving lip (p = 0.012) and tongue (p = 0.002) behavioral alterations, as well as malocclusion (p = 0.010), were significantly more prevalent in the altered frenulum group. Regression analyses demonstrated that altered frenulum independently predicted tongue-related swallowing dysfunction (OR = 2.513, p = 0.015), whereas breathing disturbance showed the strongest independent predictor (OR = 5.249, p < 0.001). Conclusion Lingual frenulum morphology was associated with reduced tongue mobility and domain-specific functional impairments, particularly in swallowing. These findings support the integration of functional evalua tion alongside structural assessment in the clinical management of ankyloglossia.
Reusable photo-crosslinked acrylate networks incorporating coumarin and S-CQDs for trace-level picric acid detection
(Elsevier, 2026) Toprak, Yunus Emre; Bulut, Mustafa; Artuç, Gamze Özgül; Uyumaz Cengiz, Fatmanur; Çubuk, Soner; Kahraman, Memet Vezir
Translating liquid-based luminescent nanomaterials into functional solid-state systems remains a major hurdle in environmental analysis. To address this limitation, this work presents the development of a structurally durable, multi-component polymeric sensor specifically engineered for the trace-level recognition of picric acid (PA). The sensing platform was formulated by embedding heteroatom-modified carbon nanodots (S-CQDs) alongside a custom-synthesized acrylated coumarin precursor within a tightly cross-linked UV-cured acrylate matrix. By confining the active phase within this polymeric architecture, the water-dispersible quantum dots are retained within a solid support while preserving their luminescent behavior. Upon exposure to PA, the formulated composite film (F2) exhibits pronounced fluorescence attenuation. The observed quenching is interpreted as an association-assisted process with possible contributions from photoinduced electron transfer (PET) and spectral- overlap-related effects. Under the optimized conditions, the sensor exhibited a linear response over 9.70 × 10 8–4.05 ×10 6 mol L 1 (R2 =0.9924), with a limit of detection of 2.25 ×10 8 mol L 1, a limit of quanti fication of 7.50 ×10 8 mol L 1, and a response time of approximately 20 s. The F2 film showed preferential fluorescence quenching toward PA compared with the investigated metal ions, aromatic species, and nitro aromatic compounds. The film retained approximately 95% of its baseline emission after 150 sensing/regener ation cycles and after two months of ambient storage. Practical applicability was demonstrated using real soil samples spiked with PA prior to extraction, yielding recoveries of 98.5–102.4% with RSD values of 1.4–2.1%. These results support the use of the S-CQD/acrylated-dicoumarin acrylate film as a reusable solid-state fluo rescence platform for PA determination.
Thermodynamic performance of a compression-ignition engine fueled with a diesel–fuel oil blend with nanographene addition and oxyhydrogen enrichment: Energy and exergy analysis
(Elsevier, 2026) Arslan, Ömer; Özer, Salih; Doğan, Battal; Tunçer, Erdal
This study examines how adding nanographene and enriching with oxyhydrogen (HHO) affect the energy and exergy performance of diesel–fuel oil blends in a compression-ignition engine. Nanographene was introduced to the DF40 blend (60% diesel, 40% fuel oil by volume) at 50 and 100 ppm, and HHO was supplied to the intake manifold at 5 and 10 L min 1 . Engine tests were performed at 3000 rpm with loads ranging from 3.2 to 12.8 Nm. The combined use of nanographene and HHO enhanced thermodynamic performance. At a load of 7.9 Nm, thermal and exergy efficiencies increased from 20.53% and 19.25% for DF40 to 25.80% and 23.72% for DF40N100H10, respectively. Maximum thermal and exergy efficiencies reached 31.66% and 29.11% at 12.8 Nm, while exergy destruction decreased by up to 23.1%. These results demonstrate the potential of nanographene addition and HHO enrichment to improve the thermodynamic performance of diesel–fuel oil blends under the tested conditions.
Performance, emission, energy, and exergy assessment of gasoline–1-decanol, gasoline–dipe, and JP-8 fuels toward sustainable two-stroke uav propulsion
(MDPI Publishing, 2026) Demir, Usame; Gülcan, Halil Erdi; Özer, Salih; Tunçer, Erdal
This study experimentally investigates the performance, emission, energy, and exergy characteristics of six fuels in a two-cylinder, air-cooled, two-stroke unmanned aerial vehicle (UAV) engine, using neat gasoline (G100) as the reference fuel. The test matrix comprised G100, neat JP-8, gasoline–1-decanol blends containing 10 and 20 vol.% decanol (G90D10 and G80D20), and gasoline–diisopropyl ether blends containing 10 and 20 vol.% DIPE (G90E10 and G80E20). Experiments were conducted at shaft speeds of 3250, 3750, 4500, 5250, and 6250 rpm under matched speed–load conditions. Fuel consumption, exhaust-gas temperature, excess-air ratio, gaseous emissions, and first- and second-law thermodynamic performance were evaluated. The inclusion of G100 enabled the effects of the oxygenated additives to be quantified directly. At 5250 rpm, G90E10 reduced BSFC by 0.73% relative to G100 while increasing energy and exergy efficiencies by 1.69% and 1.61%, respectively. G80E20 produced larger reductions in brake-specific CO and HC emissions, 6.63% and 14.58%, respectively, and increased energy and exergy efficiencies by 2.43% and 2.27%, respectively, although both DIPE blends increased NOx. In contrast, increasing the decanol fraction increased BSFC and reduced thermodynamic efficiency relative to G100 despite moderate reductions in CO. JP-8 showed the strongest operating-point dependence; at 5250 rpm its BSFC was 9.52% lower than G100 and its energy and exergy efficiencies were 12.33% and 12.84% higher, respectively, whereas its advantage diminished markedly at the highest speed. Overall, the results demonstrate that oxygenate type and concentration produce distinct trade-offs between fuel utilization and gaseous emissions, while the suitability of JP-8 for gasoline-oriented two-stroke UAV propulsion is strongly dependent on operating conditions. From an operational-sustainability perspective, the results show that improvements in fuel utilization and incomplete-combustion emissions are strongly fuel and operating-point dependent. However, fuel production pathways, life-cycle greenhouse-gas emissions, durability, economic impacts, and mission-level environmental effects were outside the scope of this study and should be addressed before broader sustainability conclusions are drawn.
Comprehensive analyses of sox7 provide novel insights on its tumor suppressor role and its target genes with therapeutic implications in multiple myeloma
(MDPI Publishing, 2026) Ceylan, Arda; Hu, Xiaozhou; Hatipoğlu, Tevfik; Nainkwi, Fenangi Chiara; Payzın, Kadriye Bahriye; Özsan, Güner Hayri; Şirinoğlu Demiriz, Itır; Şeker, Ömer; Kakçı, Merve; Küçük, Can
Multiple myeloma (MM) is an incurable hematological malignancy. SOX7, located within the recurrently deleted 8p23.1 region in MM, is suggested to act as a tumor suppressor. We characterized SOX7 through genetic, epigenetic, and functional analyses in MM cell lines. SOX7 was frequently silenced due to deletion and/or promoter hypermethylation. Ectopic SOX7 expression in KMS-18 and MM.1S cell lines caused a progressive decline in SOX7-transduced cells and induced G1 cell cycle arrest and/or apoptosis. Although SOX7 re-expression did not enhance bortezomib efficacy, treatment with the pan-histone deacetylase inhibitor panobinostat induced G1 arrest, promoted apoptosis, and increased SOX7 expression in MM.1S cells. Whole-transcriptome sequencing identified G1/S progression-related Wnt/β-catenin pathway genes as major SOX7-regulated targets, while ChIP-Seq analysis revealed widespread genomic SOX7 occupancy in MM.1S. Flow cytometric analysis of permeabilized bone marrow tumor cells from newly diagnosed and relapsed MM patients demonstrated generally low SOX7 protein expression. Collectively, these results indicate that SOX7 functions as a tumor suppressor in MM, and its inactivation promotes cell cycle progression. The anti-myeloma effects of panobinostat in MM.1S cells may be partially mediated through SOX7 induction.
