It has been shown that stem cells are able to calcify both in vitro and in vivo once implanted under the skin, if conveniently differentiated. Nowadays, however, a study on their efficiency in osseous regeneration doe...It has been shown that stem cells are able to calcify both in vitro and in vivo once implanted under the skin, if conveniently differentiated. Nowadays, however, a study on their efficiency in osseous regeneration does not exist in scientific literature and this very task is the real aim of the present experimentation. Five different defects of 6 mm in diameter and 2 mm in depth were created in the calvaria of 8 white New Zealand rabbits. Four defects were regenerated using 2 different conveniently modified scaffolds(Bio-Oss Block and Bio-Oss Collagen, Geistlich),with and without the aid of stem cells. After the insertion, the part was covered with a collagen membrane fixed by 5 modified titan pins(Altapin). The defect in the front was left empty on purpose as an internal control to each animal.Two animals were sacrificed respectively after 2, 4, 6, 10 weeks. The samples were evaluated with micro-CT and histological analysis. Micro-CT analysis revealed that the quantity of new bone for samples with Bio-Oss Block and stem cells was higher than for samples with Bio-Oss Block alone. Histological analysis showed that regeneration occurred in an optimal way in every sample treated with scaffolds. The findings indicated that the use of adult stem cells combined with scaffolds accelerated some steps in normal osseous regeneration.展开更多
We consider numerical approximation of spectral fractional Laplace-Beltrami problems on closed surfaces.The proposed numerical algorithms rely on their Balakrishnan integral representation and consists a sinc quadratu...We consider numerical approximation of spectral fractional Laplace-Beltrami problems on closed surfaces.The proposed numerical algorithms rely on their Balakrishnan integral representation and consists a sinc quadrature coupled with standard finite element methods for parametric surfaces.Possibly up to a log term,optimal rate of convergence are observed and derived analytically when the discrepancies between the exact solution and its numerical approximations are measured in L^(2)and H^(1).The performances of the algorithms are illustrated on different settings including the approximation of Gaussian fields on surfaces.展开更多
文摘It has been shown that stem cells are able to calcify both in vitro and in vivo once implanted under the skin, if conveniently differentiated. Nowadays, however, a study on their efficiency in osseous regeneration does not exist in scientific literature and this very task is the real aim of the present experimentation. Five different defects of 6 mm in diameter and 2 mm in depth were created in the calvaria of 8 white New Zealand rabbits. Four defects were regenerated using 2 different conveniently modified scaffolds(Bio-Oss Block and Bio-Oss Collagen, Geistlich),with and without the aid of stem cells. After the insertion, the part was covered with a collagen membrane fixed by 5 modified titan pins(Altapin). The defect in the front was left empty on purpose as an internal control to each animal.Two animals were sacrificed respectively after 2, 4, 6, 10 weeks. The samples were evaluated with micro-CT and histological analysis. Micro-CT analysis revealed that the quantity of new bone for samples with Bio-Oss Block and stem cells was higher than for samples with Bio-Oss Block alone. Histological analysis showed that regeneration occurred in an optimal way in every sample treated with scaffolds. The findings indicated that the use of adult stem cells combined with scaffolds accelerated some steps in normal osseous regeneration.
基金supported by the NSF(Grants DMS-1817691,DMS-2110811).
文摘We consider numerical approximation of spectral fractional Laplace-Beltrami problems on closed surfaces.The proposed numerical algorithms rely on their Balakrishnan integral representation and consists a sinc quadrature coupled with standard finite element methods for parametric surfaces.Possibly up to a log term,optimal rate of convergence are observed and derived analytically when the discrepancies between the exact solution and its numerical approximations are measured in L^(2)and H^(1).The performances of the algorithms are illustrated on different settings including the approximation of Gaussian fields on surfaces.
