İstanbul Sağlık ve Teknoloji Üniversitesi Kurumsal Akademik Arşivi
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The effect of commonly used polishing protocols on the color stability of 3D- printed temporary crowns
No full textOBJECTIVE: Color stability is a crucial parameter for maintaining the long-term esthetic success of temporary restorations. This study aimed to evaluate the effects of different clinical polishing protocols applied to three-dimensional (3D) printed temporary resin crowns on their color stability. MATERIALS-METHODS: Fifty standardized specimens (12×12×2 mm) were prepared using a 3D printing resin material (PowerResins, Temp Resin, A2, Turkiye) and randomly divided into five groups (n=10) as G1: Control (no polishing), G2: Mechanical polishing (DCPT 14 RA SET), G3: Silicon dioxide containing polishing paste (Promida Prophy P), G4: Mechanical + silicon dioxide paste, G5: Diamond particle-containing polishing paste (Intensiv Unigloss). Initial color measurements were performed using a digital spectrophotometer (Vita Easyshade V). TSpecimens were exposed to a daily coffee cycle for 15 days. Color differences were calculated using the CIEDE2000 (ΔE00) formula, and the data were analyzed by one way analysis of variance (ANOVA). Tukey’s post-hoc test was applied for multiple comparisons (p 0.05). After staining, intergroup differences were statistically significant (p < 0.05). The lowest ΔE00 values were recorded in G5 (diamond particle- containing polish). G3 and G4 exhibited moderate color changes, comparable to the control group (G1). The highest color change was observed in G2 (mechanical polishing only), with ΔE00 values exceeding the clinically perceptible threshold (ΔE00 ≥ 0.8). CONCLUSION: The diamond particle-containing polishing paste provided the best color stability both statistically and clinically. The polishing protocol plays a decisive role in the color stability of 3D-printed temporary crowns. The use of diamond-containing polishing systems is recommended, particularly in esthetic zone restorations
Impact of caffeic acid phenethyl esther on periodontal ligament cell line for wound healing and gene expression levels
No full textBu çalışma, çocuk hastalarda ebeveynlerin sentetik ilaçlara kıyasla daha fazla tercih ettikleri bitkisel ve doğal tedavi yöntemlerine bir alternatif olarak, periodontal hastalıkların önlenmesi ve tedavisinde kafeik asit fenetil ester'in (KAFE) periodontal ligament (PDL) hücre hattına uygulanması ile hücre canlılığı, yara kapanması ve yara iyileşmesindeki markör genlerin moleküler seviyede etkisini göstermeyi amaçlamaktadır. KAFE propoliste bulunan çok geniş spektrumlu bir biyoaktif bileşendir. Yetişkin hastadan alınan PDL hücre hattı ile yapılacak olan çalışma için Etik Kurulu onayı alınmış ve çalışmaya dahil edilmiştir. PDL hücreleri kültür ortamına alınmış ve pasajlanmıştır. Pasajlanan kültürlerde hücre canlılığını arttırıcı doz araştırılmış ve 2.5 µM KAFE uygulanan hücrelerde 48. saatin sonunda istatistiksel olarak anlamlı olarak hücre canlılığının arttığı gözlemlenmiştir (p=0.007). Çalışmanın diğer aşamaları olan yara kapanması çizik testi ve yara iyileşmesinde markör genlerin etkinliğinin gösterilmesi için PDL hücrelerinde canlılığı artırıcı etkisini göstermiş olduğumuz 2.5 µM KAFE dozu seçilmiş ve çalışma bu şekilde devam ettirilmiştir. Çizik testinde 2.5 µM KAFE uygulanan PDL hücre hatlarında kontrol grubuna kıyasla yaklaşık olarak 2.8 kat yara kapanmasını arttırıcı etki gösterilmiştir (p=0,00001). Bu sonuç ile beraber KAFE'nin PDL hücre hatlarında hem hücre canlılığını hem de yara iyileşmesini arttırıcı etkisi gösterilmiştir. Bu etkinin moleküler seviyede desteklenmesi için yara iyileşmesi ile ilişkili markör genlerin ifadelerine bakılmıştır. Hücre proliferasyonunda etkili olan PI3K/AKT/mTOR sinyal yolağı, Bcl-2 anti apoptotik geni ve oksidatif streste etkili NF-κB transkripsiyon faktörüne etkileri de gösterilerek KAFE'nin PDL hücre hatlarında yara iyileşmesine etkisi moleküler düzeyde desteklenmiştir. Günümüz koşullarında hastalar sentetik ilaçlar yerine bitkisel ve doğal alternatiflere hızla yönelmektedir. Özellikle çocuk hastalarda ebeveynler sentetik ilaçların yan etkileri ve güvenilir bulunmamaları sebebiyle doğal alternatiflere daha fazla ihtiyaç duymaktadır. Yapmış olduğumuz çalışmada PDL hücre hattında KAFE'nin hücre canlılığını ve yara kapanmasını arttırıcı etkisi gösterilmiş olup moleküler seviyede markör genlerin ifadesindeki artış ile bu veri desteklenmiştir. Elde ettiğimiz veriler KAFE'nin periodontal hastalıkların tedavisinde kullanılması konusunda ümit vaadeden sonuçlar ortaya koymaktadır.The aim of this study was to find out the impact of a natural compound, which parents currently prefer instead of synthetic drugs for pediatric dentistry, caffeic acid phenethyl esther (CAPE) on periodontal ligament (PDL) cell line in terms of cell viability, wound healing and gene expression levels of marker genes at molecular level to provide a potential alternative natural compound for treatment of periodontal diseases CAPE is bioactive compound of propolis with wide spectrum. To apply experiments on periodontal ligament cell line provided by adult patient, approval of Ethics Committe has been included to study. PDL cells cultured into cell culture environment and passaged to maintain a healthy cell culture environment. In subcultured cells, dose of additive effect on cell viability has been observed and 2.5 µM CAPE concentration revealed a statistically significant result to increase cell viability after 48 hours to compare with control group (p=0.007). This additive effect dose on cell viability, 2.5 µM CAPE concentration, was selected to maintain the study which aims to find out wound healing of scratch assay and the gene expression levels of marker genes. Scratch assay found out approximately 2.8 times more wound healing for 2.5 µM CAPE concentration on PDL cell line (p=0,00001). Both of these results demonstrated the possitive affects of CAPE for wound healing and cell viability on PDL cell lines. To support this data at molecular level, expression levels of marker genes for wound healing were investigated. Wound healing affect of CAPE on PDL cell line was supported at molecular level by gene expression levels of PI3K/AKT/mTOR signalling pathway responsible for cell prolifreation, Bcl- 2 anti apoptotic gene and NF-κB transcription factor which regulates oxidative stress pathways. Recent conditions demonstrated that alternative herbal and natural compounds were preferred by patients instead of synthetic drugs. In particular for pediatric patients, synthetic drugs were evaluated non-reliable with their side effects by patients, thus, requirement of alternative natural compounds is increased. This study revealed the cell viability, wound healing affect of CAPE on PDL cell line and gene expression levels of marker genes supported this impact at molecular level. Our datas suggested CAPE as a promising natural compound to cure periodontal diseases
Impact of structural and CFD analysis on the cost of biogas-fueled gas engine exhaust pipes
No full textIn this study, the effects of exhaust pipe design used in biogas-fueled cogeneration systems on engineering performance and cost were investigated. First, the existing system was analyzed by field work, and then structural analysis was applied with CFD (Computational Fluid Dynamics). The exhaust pipe route, pipe diameter, and material thickness of the existing system were evaluated, and design improvements were suggested. It was determined that the shorter pipeline application with the changes made in the pipe route and layout reduced pressure losses. Despite the use of an exhaust pipe with a smaller diameter and made of thinner material in the proposed new design, compliance with the standards was ensured, and it was shown to be safe against wind loads with finite element analysis. Considering the calculated maximum wind load of 5.52 kN and the weight of the system, the maximum stress value was calculated as 108.691 MPa as a result of the Von Mises stress analysis applied to the exhaust pipe system in the finite element analysis. This value showed that the system was 1.56 times safer. In the deformation analysis, the maximum displacement value was measured as 0.13 mm, and this value is ideal. In the cost analysis, it was determined that the proposed new system provides a cost reduction of approximately 53% compared to the existing system. The results obtained emphasize the importance of engineering analysis in exhaust pipe design, and show the applicability of the approach to increase economic and environmental sustainability in industrial facilities
The role of exosomal microRNAs in cancer metastasis: An in-depth guide
No full textExosomes and their contents play a vital role in forming a unique communication system that carries and transmits signal molecules, which alter the physiological state of cells and are linked to the on set and progression of numerous diseases including cancers. Focusing on exosomal cargo, microRNAs (miRNAs), which are small non-coding, single-stranded RNAs that regulate gene expression of target genes, are suggested to be transferred via exosomes in a selective manner that facilitates cancer progres sion and dissemination. In this context and through ongoing cancer research, researchers have currently been focusing on exosomal microRNA as a specific communication message delivered from cancer cells to the other cells that plays a crucial role in the immune response, tumor migration, tumor cell invasion, and development of metastasis In this review, we aim to evaluate the expected role of exosome-derived microRNAs in the development of cancer metastasis and their possible role of molecular markers in metastasis sites by the current literature on cancer research
Схема распределения секретного изображения с пороговым доступом в многоуровневой секционной структуре
No full textTraditional secret sharing schemes assume that all participants within a group or compartment possess equal authority in reconstructing the secret. However, in many real-world applications, such as hierarchical organizational structures or secure multi-party collaborations, this assumption does not hold. To address this limitation, we propose a novel Multilevel Compartment Threshold Secret Image Sharing (MCT-SIS) scheme that introduces hierarchical privileges within each compartment. Our scheme is based on a combination of Tassa’s hierarchical access structure and Ghodosi’s compartment model, and utilizes Birkhoff interpolation and polynomial-based techniques to achieve robust and flexible secret image sharing. Participants are grouped into disjoint compartments, each with multiple levels of access, and the secret image is shared such that it can only be reconstructed when both compartmental and hierarchical threshold conditions are satisfied. The scheme ensures perfect secrecy, lossless reconstruction, and reduced storage overhead. Experimental results validate its feasibility and demonstrate its applicability to environments requiring fine-grained access control, such as collaborative data vaults, medical imaging systems, and secure multi agency operations.Традиционные схемы распределения секрета предполагают, что все участники в группе или секции обладают равными правами на восстановление секрета. Однако во многих реальных приложениях, таких как иерархические организационные структуры или безопасное многопользовательское сотрудничество, это предположение не выполняется. Для преодоления этого ограничения мы предлагаем новую многоуровневую схему секционного распределения секретных изображений с порогом (MCT-SIS), которая вводит иерархические привилегии внутри каждой секции. Наша схема основана на сочетании иерархической структуры доступа Тассы и секционной модели Гходоси, с использованием интерполяции Биркгофа и полиномиальных методов для достижения надёжного и гибкого распределения изображений. Участники распределяются по непересекающимся секциям, каждая из которых имеет несколько уровней доступа. Секретное изображение может быть восстановлено только при соблюдении как секционных, так и иерархических пороговых условий. Схема обеспечивает идеальную секретность, безошибочное восстановление и снижение объёма хранения. Экспериментальные результаты подтверждают её эффективность и применимость в условиях, требующих детализированного управления доступом, таких как совместные хранилища данных, медицинские системы визуализации и безопасные межведомственные операции
Biomimetic management of orthodontic white spot lesions
No full textObjectives: white spot lesions (WSLs) may develop in patients with inadequate oral hygiene during orthodontic treatment. This study aimed to develop a natural remineralization agent by creating artificial WSLs in vitro. Materials/methods: WSLs were created in teeth with orthodontic buttons in vitro. The teeth were divided into the following groups: P11-4 (group 1), Nano-HA solution before sintering (group 2), Nano-HA solution after sintering (group 3), P11-4 and Nano-HA mixture before sintering (group 4), P11-4 and Nano-HA mixture after sintering (group 5), boron-containing Nano-HA mixture before sintering (group 6), boron-containing Nano-HA mixture after sintering (group 7), CPP-ACP (group 8), and artificial saliva (group 9). Measurements were taken before and after demineralization, and at the 7th, 14th, 21st, and 28th days of remineralization. Images were recorded using DIAGNOcam and VistaCamIX, area measurements were made using ImageJ, and SEM was used for remineralization assessment. Results: all groups except group 9 showed a reduction in the WSL area, with statistically significant results. SEM analysis revealed the lowest remineralization in groups 8 and 9, while the other groups exhibited more intense remineralization. Conclusions: the most successful groups for WSL remineralization were those containing pure Nano-HA (groups 2 and 3), with the other groups showing varying levels of remineralization
Labia majora lifting technique with polydioxanone threads
No full textBackground: Polydioxanone (PDO) thread is a synthetic absorbable surgical suture used for rejuvenation and lifting. Aim: The aim of this study is to use PDO threads for rejuvenation and enlargement effect in patients with labium majus hypotrophy. Methods: Twenty-one patients with labia majora hypotrophy were included in the study. Conventionally, surgery, fat filling or hyaluronic acid filling is used for labia majora rejuvenation. In this study, a different technique, the PDO thread suspension technique, was applied. For PDO thread, Hyundae Meditech Co.Ltd’s Secret Line Up product containing 50 mm screw thread with 30 G-38 mm needle tip was used. It was planned to use 10 PDO threads for right and left labia majora. After a total of 20 needles were inserted, the needles were removed one by one and the PDO threads remained in the subcutaneous superficial layer and the procedure was terminated 5 min later. Preoperative and postoperative the Female Genital Self-Image Scale (FGSIS) scores of the patients were compared. Outcomes: The overall FGSIS total score demonstrated a significant increase following the intervention. Results: The FGSIS total mean score in the preoperative period was increased in the postoperative period. This difference was statistically significant. Moreover, the mean score calculated for each parameter of FGSIS in the preoperative period increased significantly in the postoperative period. Clinical Implications: These findings indicate a favorable safety profile for the use of PDO threads in this clinical context. Strengths and Limitations: The strength of the study is to introduce a minimally invasive and effective method for labia majora lifting, on the other hand, the small number of patients in the study, limitation of the study. Conclusion: We would like to point out that in this study, we evaluated labium majus rejuvenation from the same perspective, based on the shaping and enlargement of genital appearance and its positive effect on self-confidence and increase in sexual functions. Unlike many labium majus rejuvenation procedures, this less invasive procedure has achieved similar results. In this context, it is a preferable alternative to surgery
Origin-order classification of axillary third-part branching: Donor-based dissection–CTA correlation for surgical planning
No full textPurpose Variations in the branching of the subscapular artery (SSA), anterior circumflex humeral artery (ACHA), and posterior circumflex humeral artery (PCHA) are directly relevant to reconstructive planning with subscapular-system flaps and to humeral-head perfusion in shoulder surgery. Evidence organized around an origin-order–based framework remains limited. We aimed to address this gap by comparing body-donor dissections and computed tomography angiography (CTA) to provide a clinically useful classification and morphometric reference. Methods We performed a two-arm cross-sectional morphometric study: body-donor dissection (28 donors; bilateral, 56 sides) and CTA (25 patients; bilateral, 50 sides). In total, 104 sides were evaluated; 96 were classifiable. Classification used the sequential SSA–ACHA–PCHA origin order and common-trunk presence. Ostial diameters and SSA → CSA distances were measured; the radial nerve (NR)–SSA relationship was assessed in donors. origin_order__five_type_classif… Results In donors, Type-1, -2, -3, and -4 accounted for 36.5%, 32.7%, 23.1%, and 7.7%, respectively; Type-5 was absent. In CTA, Type-1, -4, and -5 comprised 93.2%, 2.3%, and 4.5% (one bilateral case); Types-2/-3 were not observed. Inter-modality comparison showed a longer SSA → CSA distance and smaller TDA/CSA diameters in CTA (all p < 0.001), while the SSA ostial diameter was similar. A posterior NR course relative to the SSA was associated with a longer SSA → CSA distance (p = 0.026). Conclusion An origin-order–based classification, corroborated across dissection and CTA, yields a practical map for (i) single-pedicle harvesting within the subscapular system and chimeric flap design, and (ii) avoiding iatrogenic compromise of humeral-head vascularity during shoulder procedures. Incorporating presurgical CTA mapping of the SSA and its branches may enhance safety where variants (e.g., short/combined trunks, rare Type-5) are suspected
Visual quality assessment of E-commerce product images using convolutional neural networks
No full textHigh-quality product images are vital in shaping consumer trust and driving engagement on e-commerce platforms. This study proposes a deep learning-based approach for evaluating the visual quality of product images, with the aim of improving the overall customer experience and presentation standards in online marketplaces. A custom-labeled dataset was developed, containing thousands of product images categorized into five quality levels. A convolutional neural net work (CNN) was trained to classify these images based on their visual quality. In addition, two well-known architectures, MobileNetV2 and EfficientNetB0, were trained under identical conditions to serve as benchmarks for performance com parison. The proposed CNN model achieved an accuracy of 94.93%, outperforming both MobileNetV2 (76.60%) and EfficientNetB0 (92.77%). It also delivered the highest performance in terms of precision, recall, and F1-score, confirming its effectiveness in this domain. The results highlight the CNN model’s suitability for real-time quality assessment of e-commerce images. Its strong performance and efficiency make it a promising candidate for integration into commercial platforms. Future work will investigate the use of transformer-based models and more diverse training data to further improve accuracy and generalizability
Surgical anatomy of the distal part of the dorsal scapular nerve with a focus on the triple-tendon transfer
No full textIntroduction: A review of the literature shows that most studies of the dorsal scapular nerve (DSN) have focused on morphological evaluation of the proximal part of the nerve. Morphometric studies contributing to clinical applications are limited. Therefore, we aimed to investigate the topographic and morphometric anatomy of the distal part of the DSN. Methods: 13 cadavers in the Department of Anatomy, Istanbul Faculty of Medicine, were examined bilaterally. DSN dissection was performed on the anterior surface of the levator scapulae and rhomboids, and the distance to the medial border of the scapula (MBS) was recorded at different levels. The insertion lengths of the levator scapulae and rhomboids were also measured. Results: Two types of DSN were observed according to the level of termination in the muscle. Contrary to its classical course, the nerve ran laterally to the MBS on the four sides. The shortest distance between the nerve and the MBS was at the level of the superior border of the rhomboid minor (4.46 ± 9.88 mm). The insertion lengths of the levator scapulae and rhomboids according to gender and the insertion length of the rhomboid minor according to the level of termination in the muscle were significant. Discussion: We have obtained results that may be useful during Eden–Lange tendon transfer. The DSN is not always located medial to the MBS, it may be located lateral to it. To avoid nerve damage, we believe it is important to identify the nerve on the anterior surface of the muscles for a successful surgery