182,962 research outputs found
Bioresorbable glass effect on the physico-chemical properties of bilayered scaffolds for osteochondral regeneration
No full text[EN] In this work, bilayered and bioresorbable composite scaffolds are developed with mechanical and functional properties for osteochondral tissue engineering. Porous scaffolds made of gelatin (G) and bioresorbable phosphate glass (I-CEL2) with different compositions (I-CEL2/G 0/100; 30/70; 70/30 %w/w) were fabricated by freeze-drying. Samples were crosslinked using gamma-glycidoxypropyltrimethoxysilane to improve mechanical strength and thermal stability. I-CEL2/G samples showed interconnected pores having an average diameter ranging from 139 +/- 5 mu m for I-CEL2/G 0/100 to 116 +/- 9 mu m for I-CEL2/G 70/30. GPTMS-crosslinking and the increase of I-CEL2 amount stabilized the composites to water solution, as shown by swelling tests. The compressive modulus increased by increasing I-CEL2 amount up to 7.6 +/- 0.5 MPa for I-CEL2/G 70/30.The work was funded by Italian Ministry of University and Research for P. Gentile's Ph.D. Grant.Gentile, P.; Chiono, V.; Tonda-Turo, C.; Mattu, C.; Baino, F.; Vitale-Brovarone, C.; Ciardelli, G. (2012). Bioresorbable glass effect on the physico-chemical properties of bilayered scaffolds for osteochondral regeneration. Materials Letters. 89:74-76. https://doi.org/10.1016/j.matlet.2012.08.023S74768
Sintering effects of bioactive glass incorporation in tricalcium phosphate scaffolds
No full textThe influence of using bioactive glass as a sintering aid in the production of tricalcium phosphate (TCP) scaffolds was investigated. The scaffolds were fabricated by sponge replication followed by sintering in a range of temperatures from 1150 to 1300 °C. Morphological investigations by SEM and micro-computed tomography showed that the scaffolds exhibited a three-dimensional trabecular architecture mimicking that of cancellous bone, with high porosity (about 80 vol%) and highly-interconnected macropores with mean pore size of 314 μm. Apart from playing a role in improving the mechanical properties of the scaffolds, glass was shown to enhance the stability of β-TCP by increasing the β → α phase transition temperature
Collagen and non-collagenous proteins molecular crosstalk in the pathophysiology of osteoporosis
No full textCollagenous and non-collagenous proteins (NCPs) in the extracellular matrix, as well as the coupling mechanisms between osteoclasts and osteoblasts, work together to ensure normal bone metabolism. Each protein plays one or more critical roles in bone metabolism, sometimes even contradictory, thus affecting the final mechanical, physical and chemical properties of bone tissue. Anomalies in the amount and structure of one or more of these proteins can cause abnormalities in bone formation and resorption, which consequently leads to malformations and defects, such as osteoporosis (OP). The connections between key proteins involved in matrix formation and resorption are far from being elucidated. In this review, we resume knowledge on the crosstalk between collagen type I and selected NCPs (Transforming Growth Factor-β, Insulin-like Growth Factor-1, Decorin, Osteonectin, Osteopontin, Bone Sialoprotein and Osteocalcin) of bone matrix, focusing on their possible involvement and role in OP. The different elements of this network can be pharmacologically targeted or used for the design/development of innovative regenerative strategies to modulate a feedback loop in bone remodelling
Timing of HP metamorphism in the Schistes Lustrés of Alpine Corsica: New Lu-Hf garnet and lawsonite ages
No full textAlpine Corsica is crucial in understanding Western Mediterranean geodynamics. Available paleotectonic models attribute the high-pressure terrains of Corsica to the Western Alps (east dipping subduction), or to the Apennines (west-dipping subduction) or to a flip from one to the other subduction zone. Constraints on the timing of high-pressure metamorphism in Alpine Corsica are sparse and ages range from Late Cretaceous to Late Eocene. This represents a major point of debate. Here we present high-precision garnet Lu-Hf ages for three samples from the highest grade, Lawsonite-eclogite unit yielding ages of 34.23 ± 1.6. Ma; 34.11 ± 0.89. Ma, 34.65 ± 0.55. Ma. In addition to the well-established garnet dating, we employed lawsonite Lu-Hf analyses on a lawsonite-bearing (garnet-free) metagabbro from the neighboring lawsonite-blueschist unit that yielded an age of 37.5 ± 1.3. Ma. Because metamorphic temperatures of the eclogite-facies samples (ca. 500-550 °C) are below the Lu-Hf closure temperature in garnet and since the eclogitic garnet displays a core-to-rim increase in Mn concentrations typical of prograde zoning, we attribute the above Lu-Hf ages to prograde subduction metamorphism. Similarly, the age of lawsonite in the blueschist-facies unit can be safely referred to prograde-peak conditions based on the available clockwise metamorphic path. The slightly older age of the lawsonite-blueschist sample suggests a diachronous timing in the achievement of high-pressure conditions in the eclogite and in the blueschist facies units. Since both units are thought to derive from a former ocean-continent transition zone, our geochronological data provide precise time constraints to the subduction history of Alpine Corsica in the frame of the Western Mediterranean geodynamics. Our data provide Late Eocene ages for the subduction event in Corsica, which are significantly younger than previously published Cretaceous ages. This calls for partial revision of the current evolutionary models on the Corsican segment of the Alpine belt. © 2013 Elsevier B.V
URDICO - Urban Dimension of Cohesion Policy and other EU Programmes: Florence Study Report
No full textThis annex to the URDICO Final Report examines Florence and its engagement with EU Cohesion Policy and related programmes. The case highlights how Florence leverages its status as one of Italy’s 14 metropolitan cities, acting as an Intermediate Body in the National Operational Programmes for Metropolitan Cities (2014–2020 and 2021–2027), while also coordinating with the wider Metropolitan City of Florence, which encompasses 41 municipalities and around one million inhabitants. The study explores the city’s governance framework, which combines strong municipal leadership with complex metropolitan coordination. Florence has institutionalised cross-departmental management of EU projects through its European Projects and Networking Office, ensuring that EU funding supports local priorities in digital transition, sustainable mobility, social inclusion, and urban regeneration.
The report also considers the city’s role in political advocacy, both nationally and internationally, through networks such as Eurocities, the Covenant of Mayors, the Green City Accord, and the 100 Climate-Neutral Cities Mission. These activities underscore Florence’s efforts to strengthen the recognition of cities as strategic actors in Cohesion Policy. Florence demonstrates how targeted EU support, combined with active institutional and political engagement, can enhance urban governance, promote strategic priorities, and foster innovation at the city and metropolitan scale
Wollastonite-containing bioceramic coatings on alumina substrates: design considerations and mechanical modelling
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Feasibility of glass-ceramic coatings on alumina prosthetic implants by airbrush spraying method
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Modelling of the architecture of healthy and osteoporotic bone using porous bioceramic scaffolds
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