Effect of sonic hedgehog/β-TCP composites on bone healing within the critical-sized rat femoral defect

The creation of entirely synthetically derived bone substitute materials which are as effective as autologous bone grafts is desirable. Osteogenesis involves the concerted action of several proteins within a signaling cascade. Hedgehog proteins act upstream of this cascade, inducing the expression of various bone morphogenetic proteins (BMPs) and promoting physiological bone healing. Therefore, the hypothesis that hedgehog signaling in bone defects improves bone healing more than BMP signaling alone was tested. Recombinant N-terminal sonic hedgehog protein (N-SHh), BMP-2 or a combination of the two was added to β-tricalcium phosphate (β-TCP) and 5-mm femoral midshaft defects in nude rats were filled with these composites. The defects were stabilized with mini-plates. After eight weeks, the animals were sacrificed and the femora were explanted. The radiological evaluation was followed by a three-point bending test and histological examination. BMP-2/β-TCP composites showed a trend of increased stiffness compared with the controls (β-TCP without protein). N-SHh/β-TCP composites had lower stiffness compared with the control group and the N-SHh/BMP-2/β-TCP composites also had lower average stiffness compared with the controls (all not significant). Histomorphometry, however, revealed abundant cartilage and bone core formation in the N-SHh-composite groups. The sum of the new cartilage and bone was highest in the combination group N-SHh/BMP-2 (not significant). The addition of N-SHh to bone substitute materials appears to delay bone healing at the applied concentration and observation time but also showed a trend for higher amounts of ossifying cartilage

Ana's Friends. Friendship in Online Pro-Ana Communities

The objective of this article is to analyse the social relationships within online communities of anorectics, their bonds, their emotions and friendships, and their subsequent relation to anorexia nervosa. The research has focused on their blogs and their forums, which create a space in which they share their experiences, and sometimes encourage each other not to give up on their eating disorder – which they view as an illness, but an illness that has become their lifestyle, and their attitude towards life. Within the article an analysis of the special bonds of friendship that tie the members of the online community together will be presented. Special attention will be paid to the similarities between secret societies and friendship bonds within pro-ana communities.Friendship, Secret, Emotions, Internet, Anorexia, Pro-Anorexia

Creatividad, interactividad y estructuras ocultas de poder: una reflexión sobre la historia de la realidad actual del museo a través de la mirada de Foucault

Aquest article reflexiona sobre el museu com a dispositiu i els avenços que s’han produït en aquest àmbit. Argumentant per què el museu s’ha de considerar d’aquesta manera, s’examinen els avenços del museu modern com a dispositiu, des del seu auge al segle xix fins al format digital actual. Mitjançant la reflexió històrica crítica, veiem com han canviat les estructures de poder que actuen dins del museu. Aquest article analitza com es teixeixen les relacions de poder al museu i com generen formes tant de llibertat com de regulació, segons el context historicosocial en què s’insereix. L’obertura, la inclusió i la participació apareixen com a conceptes clau que faciliten una millor comprensió de les estructures de poder dins del museu digital contemporani. Aquests conceptes clau ajudaran a explicar per què i de quina manera el museu com a dispositiu es connecta i es relaciona amb la societat actual. S’examinen els perills que això implica partint de tres dimensions clau que apareixen en els museus: el museu com a espai d’experiència, com a efecte individual i extracció de dades, i com a lloc per a la producció creativa i l’autoexplotació. En conclusió, l’objectiu d’aquest article no és solament destacar els aspectes més importants i crítics del museu contemporani, sinó també proposar suggeriments per a millores futures.This article reflects on the developments of and concerning the museum as a dispositive. It argues why the museum must be considered a dispositive. Then it follows the developments of the modern museum as a dispositive from its rise in the 19th century towards its current digital form. A critical historical reflection shows how structures of power, working within the museum, have changed. This article presents how relations of power in the museum are being woven, and how they produce respectively forms of freedom and regulation, according to the socio-historical context of which the museum is a part. Openness, inclusion and participation appear as key concepts that facilitate a better understanding of the structures of power within the late modern digital museum. These key concepts will help explain why and how the museum as a dispositive connects and relates with late modern society. Corresponding dangers will be pointed out along 3 key dimensions that can be found in the museum – the museum as place of experience, the museum as place of individual effect and data extraction, and the museum as place of creative production and self-exploitation. As a conclusion, the article wants not only to point at important and critical aspects of the late modern museum, but also to provide suggestions for improvements in the future.Este artículo reflexiona sobre el museo como dispositivo y los avances que se han producido en este ámbito. Argumentando por qué el museo debe considerarse de este modo, se examinan los avances del museo moderno como dispositivo, desde su auge en el siglo xix hasta su actual formato digital. Mediante la reflexión histórica crítica, vemos cómo han cambiado las estructuras de poder que actúan dentro del museo. Este artículo analiza cómo se tejen las relaciones de poder en el museo y cómo generan formas tanto de libertad como de regulación, según el contexto historicosocial en el que se insiere. La apertura, la inclusión y la participación aparecen como conceptos clave que facilitan una mejor comprensión de las estructuras de poder dentro del museo digital contemporáneo. Estos conceptos clave ayudarán a explicar por qué y cómo el museo como dispositivo se conecta y se relaciona con la sociedad actual. Se examinan los peligros que ello supone partiendo de tres dimensiones clave que aparecen en los museos: el museo como espacio de experiencia, como espacio de efecto individual y extracción de datos, y como lugar para la producción creativa y la autoexplotación. En conclusión, el objetivo de este artículo no es solo destacar los aspectos más importantes y críticos del museo contemporáneo, sino también proponer sugerencias para futuras mejoras

The investigation of the production environment factors through the prism of the game process

У сучасному світі широко використовується гейміфікація, як один з найбільш ефективних підходів в навчанні. Гейміфікація застосовується з метою залучення користувачів, підвищення їхньої зацікавленості у вирішенні прикладних завдань. Однією з найбільш ефективних методик виступає ділова гра. У процесі її моделювання визначається проблемна ситуація, і мета гри полягає в пошуку шляхів її вирішення. Ділові ігри застосовуються як в освітній, так і діловій сферах. Важливе значення ділових ігор полягає також в тому, що вони сприяють встановленню відносин співробітництва викладача і студентів, обумовлюють формування позитивного емоційно-психологічного клімату на заняттях. Розроблена і впроваджена в навчальний процес робота "Office Explorer" - це візуальний інструмент у вивченні впливу факторів виробничого середовища і трудового процесу на стан здоров'я людини і навколишнього середовища. Створена така універсальна програма, яка в ігровій формі доступно, не нав'язливо донесе інформацію до студента, заставить проаналізувати, засвоїти, зробити правильні висновки, обрати необхідні засоби і заходи захисту від впливу шкідливих чинників виробничого середовища і трудового процесу. Програма "Office Explorer" об'єднала в собі всі ці вимоги до комп'ютерних лабораторних робіт і стала незамінним інструментом в засвоєнні знань і практичних навичок з дисциплін "Безпека життєдіяльності" та "Основ охорони праці". Реалізований підхід є найсучаснішим рішенням висвітленої проблеми сучасних заходів навчання та оцінювання знань студентів ВНЗ. Використання цього підходу дозволяє автоматизувати навчальний процес, а також готує майбутнього спеціаліста до умов вирішення реальних проблем. Використання подібних робіт при різних формах навчання дуже важливо і необхідно в сучасних умовах.In the modern world, gaming is widely used as one of the most effective approaches in the teaching. Gaming is used to attract users, increase their interest in solving applied problems. One of the most effective techniques is the business game. In the process of its simulation, the problem situation is determined, and the purpose of the game is to find ways to solve it. Business games are applied both in educational and business spheres. The importance of business games is also that they contribute to the establishment of relations between the teacher and students, which determine the formation of a positive emotional and psychological climate in the classes. The "Office Explorer" work developed and implemented in the educational process is a visual tool in studying the influence of the working environment factors and the working process on the condition of human health and the environment. The Office Explorer program combines all these requirements with computer labs and has become an indispensable tool in acquiring knowledge and practical skills in the disciplines "Security of Life" and "Fundamentals of Occupational Safety". The implemented approach is the most up-to-date solution of the illuminated problem of modern educational measures and assessment of students' knowledge of universities. Using this approach allows you to automate the learning process, as well as prepare a future specialist for the conditions for solving real problems. The using of such works in various forms of training is very important and necessary in the modern conditions

High calcium bioglass enhances differentiation and survival of endothelial progenitor cells, inducing early vascularization in critical size bone defects

Early vascularization is a prerequisite for successful bone healing and endothelial progenitor cells (EPC), seeded on appropriate biomaterials, can improve vascularization. The type of biomaterial influences EPC function with bioglass evoking a vascularizing response. In this study the influence of a composite biomaterial based on polylactic acid (PLA) and either 20 or 40% bioglass, BG20 and BG40, respectively, on the differentiation and survival of EPCs in vitro was investigated. Subsequently, the effect of the composite material on early vascularization in a rat calvarial critical size defect model with or without EPCs was evaluated. Human EPCs were cultured with β-TCP, PLA, BG20 or BG40, and seeding efficacy, cell viability, cell morphology and apoptosis were analysed in vitro. BG40 released the most calcium, and improved endothelial differentiation and vitality best. This effect was mimicked by adding an equivalent amount of calcium to the medium and was diminished in the presence of the calcium chelator, EGTA. To analyze the effect of BG40 and EPCs in vivo, a 6-mm diameter critical size calvarial defect was created in rats (n = 12). Controls (n = 6) received BG40 and the treatment group (n = 6) received BG40 seeded with 5×105 rat EPCs. Vascularization after 1 week was significantly improved when EPCs were seeded onto BG40, compared to implanting BG40 alone. This indicates that Ca2+ release improves EPC differentiation and is useful for enhanced early vascularization in critical size bone defects

Synthesis of novel β-aminocyclobutanecarboxylic acid derivatives by a solvent-free aza-Michael addition and subsequent ring closure

Novel beta-aminocyclobutanecarboxylic acid derivatives were prepared via a sequential solvent-free aza-Michael addition of benzophenone imine across 3-halopropylidenemalonates and base-induced ring closure. These highly substituted cyclobutanedicarboxylic acid derivatives were subjected to a reactivity study which demonstrated the tendency of these donor-acceptor substituted four-membered rings to be converted into their corresponding ring-opened products

Human endothelial-like differentiated precursor cells maintain their endothelial characteristics when cocultured with mesenchymal stem cell and seeded onto human cancellous bone

Introduction. Cancellous bone is frequently used for filling bone defects in a clinical setting. It provides favourable conditions for regenerative cells such as MSC and early EPC. The combination of MSC and EPC results in superior bone healing in experimental bone healing models. Materials and Methods. We investigated the influence of osteogenic culture conditions on the endothelial properties of early EPC and the osteogenic properties of MSC when cocultured on cancellous bone. Additionally, cell adhesion, metabolic activity, and differentiation were assessed 2, 6, and 10 days after seeding. Results. The number of adhering EPC and MSC decreased over time; however the cells remained metabolically active over the 10-day measurement period. In spite of a decline of lineage specific markers, cells maintained their differentiation to a reduced level. Osteogenic stimulation of EPC caused a decline but not abolishment of endothelial characteristics and did not induce osteogenic gene expression. Osteogenic stimulation of MSC significantly increased their metabolic activity whereas collagen-1α and alkaline phosphatase gene expressions declined. When cocultured with EPC, MSC’s collagen-1α gene expression increased significantly. Conclusion. EPC and MSC can be cocultured in vitro on cancellous bone under osteogenic conditions, and coculturing EPC with MSC stabilizes the latter’s collagen-1α gene expression