853 research outputs found
Growth and differentiation of human bone marrow osteoprogenitors on novel calcium phosphate cements
No full textMaterials that augment bone cell proliferation and osteogenic activity have important therapeutic implications for bone regeneration and for use in skeletal reconstruction and joint replacement. We have studied the growth and interactions of human bone marrow cells on a variety of new cement composites in vitro. These cement materials are composed of calcium-deficient hydroxyapatites, carbonated apatite and amorphous calcium phosphate. Cell proliferation was significantly reduced and cell differentiation increased in the presence of these cements compared with cells cultured on tissue culture plastic. Alkaline phosphatase, one of the markers of the osteoblast phenotype, was dramatically stimulated by 3 of the 4 cements examined between day 4 and day 10, above levels observed following culture of human osteoblasts on plastic alone. Photomicroscopic examination demonstrated growth and close integration of bone marrow cells and 3 of the composites. Longer term marrow cultures (15 day) on the cements confirmed the stimulation of cell differentiation over proliferation. From these studies, enhanced osteoblastic differentiation was observed on a 70% carbonated apatite, which has a composition similar to bone mineral, whereas, cell toxicity was observed on cells grown on amorphous calcium phosphate. This in vitro culture system demonstrates the use of human bone marrow cells for the potential evaluation of new biomaterials and the development of a novel carbonated apatite that may be of potential use in orthopaedic implant
Effects of novel calcium phosphate cements on human bone marrow fibroblastic cells
No full textThe identification and characterization of biocompatible materials that augment bone cell proliferation and osteogenic activity have important therapeutic implications in skeletal reconstruction and joint replacement. In the present study, we have examined the effects of three biocements, biocement H, calcium-deficient apatite; biocement F, apatite + CaHPO(4); biocement D, carbonated apatite + CaHPO(4) + CaCO(3) and an amorphous calcium phosphate (ACP) proposed as implant fixing materials, on the growth, differentiation, and cell surface interaction of human bone marrow fibroblastic cells. These cells are known to be progenitors of osteoblasts, chondroblasts, adipocytes, myoblasts, and reticulocytes. Alkaline phosphatase enzyme activity, a marker of the osteoblast phenotype, was increased by a factor of two- to sixfold on carbonated apatite, one- to sixfold on apatite and three- to 10-fold on calcium-deficient apatite, over levels observed on plastic. Cell proliferation was significantly reduced. Photomicroscopic examination indicated high biocompatibility with close adhesion of the bone marrow fibroblastic cells to composites D, F, and H. Longer term marrow cultures (15 days) confirmed the stimulation of cell differentiation, as assessed by collagen production, over cell proliferation, of cells grown on carbonated apatite. Enhanced osteoblastic differentiation was observed on a 70% carbonated apatite, which has a composition similar to bone mineral, whereas cell toxicity was observed on cells grown on amorphous calcium phosphate. This in vitro human bone marrow fibroblast culture system provides a simple and effective method for the evaluation of new biomaterials. The development of these novel cements may be of potential use in orthopedic implant
A handle on charge reorganization
No full textGreen Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.ChemE/Opto-electronic Material
Marginalization and contemporaneous aggregation in multivariate GARCH processes
No full textTime Series;GARCH Models
Materialien für Münzgesetzgebung und dabei entstehende Erörterungen ...
No full textAttributed to F.C. Cleynmann.Mode of access: Internet
Broadband communication: Modeling, analysis and synthesis of an ATM switching element
No full textElectrical Engineering, Mathematics and Computer Scienc
Efficient Broadband: Performance analysis and design of ATM networks
No full textElectrical Engineering, Mathematics and Computer Scienc
: From material objects to digital data: multi-scale and multi-temporal digitalization challenges
No full textContributeurs : Florent Comte, Eloi Gattet, El Mustapha Mouaddib, Anthony Pamart, Renato Saleri, Livio De Luca, Aurore Pfitzmann // Author contributions : Conceptualization: F.C.; Data curation: F.C., E.G., E.M.M., A.P., R.S.; Formal analysis: ; Funding acquisition: L.D.L.; Investigation: ; Methodology: ; Project administration: L.D.L., A.P.; Resources: ; Software: ; Supervision: L.D.L.; Validation: L.D.L.; Visualization: F.C., E.G., E.M.M., A.P., R.S.; Writing – original draft: F.C., E.G., E.M.M., A.P., R.S.; Writing – review & editing: F.C.International audienceDescription des réflexions et des outils utilisés pour la numérisation 3D dans le cadre du Chantier Scientifique de Notre-Dame de Paris
Des données numériques aux connaissances pluridisciplinaires : enjeux de documentation et de formalisation
No full textContributeurs : Violette Abergel, Pierre Arese, Florent Comte, Iwona Dudek, Anaïs Guillem, Antoine Gros, Kévin Réby, Livio De Luca, Aurore Pfitzmann, Pascal Bénistant //Author contributions : Conceptualization: V.A., P.A., F.C., I.D., A.Gu., A.Gr., K.R.; Data curation: V.A., P.A., F.C., I.D., A.Gu., A.Gr., K.R.; Formal analysis: ; Funding acquisition: L.D.L.; Investigation: ; Methodology: V.A., P.A., F.C., I.D., A.Gu., A.Gr., K.R.; Project administration: L.D.L., A.P.; Resources: P.B.; Software: ; Supervision: L.D.L.; Validation: L.D.L.; Visualization: V.A., P.A., F.C., I.D., A.Gu., A.Gr., K.R.; Writing – original draft: V.A., P.A., F.C., I.D., A.Gu., A.Gr., K.R.; Writing – review & editing: V.A., P.A., F.C., I.D., A.Gu., A.Gr., K.R.International audiencePrésentation des procédés de gestion et de structuration des données acquises lors du Chantier Scientifique de Notre-Dame de Pari
- …
