Stronsiyum katkısının biyocam doku iskelesinin özelliklerine olan etkisinin incelenmesi

06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır.Bu çalışmada SiO2-Na2O-P2O5-B2O3-CaO sistemine sahip biyoaktif cam bileşimi temel alınmış ve stronsiyum katkısının biyoaktivite özelliklerine olan etkisi incelenmiştir. Dört farklı oranda (ağırlıkça % 0 , % 0.5, % 1, % 2) stronsiyum içeren biyoaktif cam bileşimleri ergitme yöntemi ile üretilmiştir. Camların fiziksel ve biyolojik özellikleri incelenmiş ve camlar daha sonra doku iskelesi üretimi için -45µm tane boyutuna sahip olacak şekilde öğütülerek toz haline getirilmiştir. Elde edilen biyoaktif cam tozlarından polimer sünger kopyalama tekniği kullanılarak doku iskelesi üretimi gerçekleştirilmiştir. Doku iskeleleri biyoaktivite analizleri için belirli sürelerle (1, 7, 14 ve 28 gün) yapay vücut sıvısı içerisinde bekletilmeleri sonrası yüzey karakterizasyonları ve biyoaktivite analizleri XRD, SEM ve EDS analizi kullanılarak yapılmıştır. Sonuçlar stronsiyum ilavesinin biyoaktivite özelliklerini olumlu yönde arttırdığını doğrularken, ilave edilen stronsiyum oranları ile biyoaktivite arasında net bir ilişki bulunamamıştır.In the current study, the effect of strontium addition on bioactivity properties was investigated by using SiO2-Na2O-P2O5-B2O3-CaO glass composition. Four different glass compositions having 0-0.5-1-2 wt.% strontium were produced with melting process. Physical and biological properties of glass were studied and then these glasses were grinded size of -45 µm to produce tissue scaffold. These were produced from the obtained bioactive glass powders by polymer sponge copying technique. Tissue scaffolds were incubated in artificial body fluid for a period of time (1, 7, 14 and 28 days) for bioactivity analysis and surface characterizations and bioactivity analyzes were performed using XRD, SEM and EDS analysis. The results approved the positive effect of strontium addition on bioactivity properties there was no clear relationship between added strontium ratios and bioactivity

A multiscale computational model of arterial growth and remodeling including Notch signaling

Blood vessels grow and remodel in response to mechanical stimuli. Many computational models capture this process phenomenologically, by assuming stress homeostasis, but this approach cannot unravel the underlying cellular mechanisms. Mechano-sensitive Notch signaling is well-known to be key in vascular development and homeostasis. Here, we present a multiscale framework coupling a constrained mixture model, capturing the mechanics and turnover of arterial constituents, to a cell-cell signaling model, describing Notch signaling dynamics among vascular smooth muscle cells (SMCs) as influenced by mechanical stimuli. Tissue turnover was regulated by both Notch activity, informed by in vitro data, and a phenomenological contribution, accounting for mechanisms other than Notch. This novel framework predicted changes in wall thickness and arterial composition in response to hypertension similar to previous in vivo data. The simulations suggested that Notch contributes to arterial growth in hypertension mainly by promoting SMC proliferation, while other mechanisms are needed to fully capture remodeling. The results also indicated that interventions to Notch, such as external Jagged ligands, can alter both the geometry and composition of hypertensive vessels, especially in the short term. Overall, our model enables a deeper analysis of the role of Notch and Notch interventions in arterial growth and remodeling and could be adopted to investigate therapeutic strategies and optimize vascular regeneration protocols.</p

Systematic Mapping Study on Performance Scalability in Big Data on Cloud Using VM and Container

Part 11: New Methods and Tools for Big Data Wokshop (MT4BD)International audienceIn recent years, big data and cloud computing have gained importance in IT and business. These two technologies are becoming complementing in a way that the former requires large amount of storage and computation power, which are the key enabler technologies of Big Data; the latter, cloud computing, brings the opportunity to scale on-demand computation power and provides massive quantities of storage space. Until recently, the only technique used in computation resource utilization was based on the hypervisor, which is used to create the virtual machine. Nowadays, another technique, which claims better resource utilization, called “container” is becoming popular. This technique is otherwise known as “lightweight virtualization” since it creates completely isolated virtual environments on top of underlying operating systems. The main objective of this study is to clarify the research area concerned with performance issues using VM and container in big data on cloud, and to give a direction for future research

Yirmi senelik kutsal uğraş : Tarih Vakfı

Ankara : İhsan Doğramacı Bilkent Üniversitesi İktisadi, İdari ve Sosyal Bilimler Fakültesi, Tarih Bölümü, 2014.This work is a student project of the The Department of History, Faculty of Economics, Administrative and Social Sciences, İhsan Doğramacı Bilkent University.by Öztürk, İbrahim Mert

Mechano-regulated cell-cell signaling in the context of cardiovascular tissue engineering

Cardiovascular tissue engineering (CVTE) aims to create living tissues, with the ability to grow and remodel, as replacements for diseased blood vessels and heart valves. Despite promising results, the (long-term) functionality of these engineered tissues still needs improvement to reach broad clinical application. The functionality of native tissues is ensured by their specific mechanical properties directly arising from tissue organization. We therefore hypothesize that establishing a native-like tissue organization is vital to overcome the limitations of current CVTE approaches. To achieve this aim, a better understanding of the growth and remodeling (G&R) mechanisms of cardiovascular tissues is necessary. Cells are the main mediators of tissue G&R, and their behavior is strongly influenced by both mechanical stimuli and cell-cell signaling. An increasing number of signaling pathways has also been identified as mechanosensitive. As such, they may have a key underlying role in regulating the G&R of tissues in response to mechanical stimuli. A more detailed understanding of mechano-regulated cell-cell signaling may thus be crucial to advance CVTE, as it could inspire new methods to control tissue G&R and improve the organization and functionality of engineered tissues, thereby accelerating clinical translation. In this review, we discuss the organization and biomechanics of native cardiovascular tissues; recent CVTE studies emphasizing the obtained engineered tissue organization; and the interplay between mechanical stimuli, cell behavior, and cell-cell signaling. In addition, we review past contributions of computational models in understanding and predicting mechano-regulated tissue G&R and cell-cell signaling to highlight their potential role in future CVTE strategies

Notch signaling regulates strain-mediated phenotypic switching of vascular smooth muscle cells

Mechanical stimuli experienced by vascular smooth muscle cells (VSMCs) and mechanosensitive Notch signaling are important regulators of vascular growth and remodeling. However, the interplay between mechanical cues and Notch signaling, and its contribution to regulate the VSMC phenotype are still unclear. Here, we investigated the role of Notch signaling in regulating strain-mediated changes in VSMC phenotype. Synthetic and contractile VSMCs were cyclically stretched for 48 h to determine the temporal changes in phenotypic features. Different magnitudes of strain were applied to investigate its effect on Notch mechanosensitivity and the phenotypic regulation of VSMCs. In addition, Notch signaling was inhibited via DAPT treatment and activated with immobilized Jagged1 ligands to understand the role of Notch on strain-mediated phenotypic changes of VSMCs. Our data demonstrate that cyclic strain induces a decrease in Notch signaling along with a loss of VSMC contractile features. Accordingly, the activation of Notch signaling during cyclic stretching partially rescued the contractile features of VSMCs. These findings demonstrate that Notch signaling has an important role in regulating strain-mediated phenotypic switching of VSMCs

Data underlying the publication "Notch signaling regulates strain-mediated phenotypic switching of vascular smooth muscle cells"

The data and resulting publication show the role of Notch signaling in regulating strain-mediated phenotypic switching of vascular smooth muscle cells. The dataset consists of custom-built scripts for strain analysis, stretch quantification data, immunofluorescence staining and real-time polymerase chain reaction data

Data belonging to the publication "A multiscale computational model of arterial growth and remodeling including Notch signaling"

This study presents a multiscale computational framework coupling a constrained mixture model, capturing the mechanics and turnover of arterial constituents, to a cell-cell signaling model, describing Notch signaling dynamics among vascular smooth muscle cells. Tissue turnover was regulated by both Notch activity, informed by in vitro data obtained from human coronary artery smooth muscle cells, and a phenomenological contribution, accounting for mechanisms other than Notch. The framework was used to predict changes in wall thickness and arterial composition in response to hypertension and thereby demonstrated the effects of Notch signaling and Notch interventions on this process. This dataset contains the computational codes for the multiscale framework (i.e. the constrained mixture model and the Notch signaling model), the codes for the data fitting and optimization, and the raw data from the simulations and the in vitro experiments used to inform the model

Data underlying the publication "Notch signaling regulates strain-mediated phenotypic switching of vascular smooth muscle cells"

The data and resulting publication show the role of Notch signaling in regulating strain-mediated phenotypic switching of vascular smooth muscle cells. The dataset consists of custom-built scripts for strain analysis, stretch quantification data, immunofluorescence staining and real-time polymerase chain reaction data. </p