Platelet-rich fibrin (PRF) is an autologous platelet concentrate that consists of cytokines, platelets, leukocytes, and circulating stem cells. It has been considered to be effective in bone regeneration and is mainly used for oral and maxillofacial bone. Although currently the use of PRF is thought to support alveolar ridge preservation, there is a lack of evidence regarding the application of PRF in osteogenesis. In this paper, we will provide examples of PRF application, and we will also summarize different measures to improve the properties of PRF for achieving better osteogenesis. The effect of PRF as a bone graft material on osteogenesis based on laboratory investigations, animal tests, and clinical evaluations is first reviewed here. In vitro, PRF was able to stimulate cell proliferation, differentiation, migration, mineralization, and osteogenesis-related gene expression. Preclinical and clinical trials suggested that PRF alone may have a limited effect. To enlighten researchers, modified PRF graft materials are further reviewed, including PRF combined with other bone graft materials, PRF combined with drugs, and a new-type PRF. Finally, we will summarize the common shortcomings in the application of PRF that probably lead to application failure. Future scientists should avoid or solve these problems to achieve better regeneration.

Background The existence of mesenchymal stem cells (MSCs) in Schneiderian membrane has not been determined. The aim of this study is to investigate whether there are MSCs in Schneiderian membrane, and the effect of platelet-rich fibrin (PRF) on osteogenic differentiation of these cells and on new bone formation in maxillary sinus after maxillary sinus floor elevation. Methods Schneiderian membrane derived mesenchymal stem cells (SM-MSCs) were isolated from rabbit maxillary sinus. Cells were identified by flow cytometry and multipotential differentiation. Real-time cell analysis assay, fluorescence staining, transwell assay, and wound healing assay were used to determine the effects of PRF stimulation on cell proliferation and migration. The osteogenic differentiation ability of cells stimulated by PRF or osteoinductive medium was evaluated by alkaline phosphatase staining, alizarin red staining, PCR and Western blot. Equivalent volume Bio-oss and the mixture of Bio-oss and PRF were used as bone graft materials for maxillary sinus floor elevation. Micro-CT, bone double-staining, HE staining, Masson staining, and toluidine blue staining were used to evaluate the osteogenic effect in 8 and 12 weeks after surgery. Results The cell surface markers were positive for expression of CD90, CD105, and negative for expression of CD34, CD45. SM-MSCs had the ability of osteogenic, adipogenic and chondrogenic differentiation. PRF could stimulate proliferation, migration and osteogenic differentiation of SM-MSCs, which was achieved by up-regulating ERK 1/2 signaling pathway. PRF could accelerate the formation of new bone in maxillary sinus and increase the amount of new bone formation. Conclusions MSCs existed in Schneiderian membrane, and PRF stimulation could promote cell proliferation, migration and osteogenic differentiation. The application of PRF in maxillary sinus floor elevation could accelerate bone healing and increase the quantity and quality of new bone. PRF, as autologous graft materials, might offer a promising strategy for the clinical bone formation during MSFE procedure. Graphical abstract

Let k be an algebraically closed field of characteristic p. Denote by W (k) the ring of Witt vectors of k. Let F denote a totally ramified finite extension of W (k)[1/p] and O the its ring of integers. For a connected reductive group scheme G over O, we study the category P L + G (Gr G , Λ) of L + G-equivariant perverse sheaves in Λ-coefficient on the affine Grassmannian Gr G where Λ = Z ℓ and F ℓ and prove it is equivalent as a tensor category to the category of finitely generated Λ-representations of the Langlands dual group of G.

In this paper, the assembly process and the material properties of MPNs are discussed, and the application scope and prospect of MPNs are clarified. This paper provides new ideas for the construction of nanoplatforms for therapeutics and diagnostics.

BackgroundThe existence of mesenchymal stem cells (MSCs) in Schneiderian membrane has not been determined. The aim of this study is to investigate whether there are MSCs in Schneiderian membrane, and the effect of platelet-rich fibrin (PRF) on osteogenic differentiation of these cells and on new bone formation in maxillary sinus after maxillary sinus floor elevation.MethodsSchneiderian membrane derived mesenchymal stem cells (SM-MSCs) were isolate from rabbit maxillary sinus. Cells were identified by flow cytometry and multipotential differentiation. Real-time cell analysis assay, fluorescence staining, transwell assay, and wound healing assay were used to determine the effects of PRF stimulation on cell proliferation and migration. The osteogenic differentiation ability of cells stimulated by PRF or osteoinductive medium (OM) was evaluated by alkaline phosphatase (ALP) staining, alizarin red staining, PCR and Western blot. Equivalent volume Bio-oss and the mixture of Bio-oss and PRF were used as bone graft materials for maxillary sinus floor elevation. Micro-CT, bone double-staining, HE staining, Masson staining, and toluidine blue staining were used to evaluate the osteogenic effect in 8 and 12 weeks after surgery.ResultsThe cell surface markers were positive for expression of CD90, CD105, and negative for expression of CD34, CD45. SM-MSCs had the ability of osteogenic, adipogenic and chondrogenic differentiation. PRF can stimulate proliferation, migration and osteogenic differentiation of SM-MSCs, which is achieved by up-regulating ERK 1/2 signaling pathway. PRF can accelerate the formation of new bone in maxillary sinus and increase the amount of new bone formation. ConclusionsMSCs exist in Schneiderian membrane, and PRF stimulation can promote cell proliferation, migration and osteogenic differentiation. The application of PRF in maxillary sinus floor elevation can accelerate bone healing and increase the quantity and quality of new bone.

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In this paper, we give a geometric construction of the Jacquet-Langlands transfer for automorphic forms of higher weights by studying the geometry of the mod p fibres of different Hodge type Shimura varieties which satisfy a mild assumption and the cohomological correspondences between them. Contents 1. Introduction 1.1. Main theorem 1.2. Plan of the paper 1.3. Notations 1.4. Acknowledgements 2. The Integral Coefficient Geometric Satake Equivalence in Mixed Characteristic 2.1. The geometry of mixed characteristic affine Grassmannians 2.2. The Satake category 2.3. More on the convolution Grassmannians 2.4. The geometric Satake equivalence 3. Local Hecke Stacks 3.1. Torsors over the local Hecke stacks 3.2. Perverse sheaves on the moduli of local Hecke stacks 4. Moduli of Local Shtukas 4.1. Moduli of restricted local Shtukas 4.2. Perverse sheaves on the moduli of local Shtukas 5. Key theorem 5.1. Set up 5.2. More on local Hecke stacks 5.3. More on moduli of local Shtukas 5.4. The category of coherent sheaves on the stack of unramified Langlands parameters 5.5. Key theorem 6. Cohomological correspondences between Shimura varieties 6.1. Preliminaries 6.2. Étale local systems 6.3. Main theorem 6.4. Non-vanishing of the geometric Jacquet-Langlands transfer References