5,027 research outputs found

    MiR-28-3p enhances healing of fracture via negative regulation of the target gene Sox6 and activation of PI3K/Akt signaling pathway

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    Purpose: To investigate the effect of miR-28-3p on fracture healing, and the involvement of Sox6 gene and PI3K/Akt signaling pathway in the process.Methods: Mouse osteoblast cell lines were cultured in vitro, and miR-28-3p over-expression and inhibitory plasmids were separately added to the medium. The corresponding control groups were set up. Real-time quantitative polymerase chain reaction (qRT-PCR) was used to measure the mRNA expressions of the osteogenesis-related genes Col1a1, Col-â…¡ and Col-X in osteoblasts. The protein expressions of Sox6, Col1a1, Col-â…¡, Col-X, PI3K, p-PI3K, Akt and p-Akt in rat cartilage tissue were determined with Western blotting assay.Results: The expression of Sox6 protein in the miR-28-3p over-expression group was significantly reduced, when compared with the miR-28 overexpression control, but Sox6 protein expression in the miR-28-3p inhibition group was significantly increased, relative to inhibition control group (p < 0.05). In the miR-28-3p over-expression and Sox6 over-expression groups, Col1a1 protein expression was significantly increased, while Col-â…¡ and Col-X protein expressions decreased, when compared with the respective over-expression control group (p < 0.05). Over-expression of miR-28-3p markedly upregulated phosphorylation levels of PI3K and Akt, relative to over-expression control group, while miR-28-3p inhibition significantly downregulated the phosphorylations of PI3K and Akt, relative to the inhibition control group (p < 0.05).Conclusion: Over-expression of miR-28-3p may enhance the healing of fractures by induction of PI3K/Akt signaling route via negative regulation of the expression of Sox6 gene. Keywords: MiR-28-3p, Sox6, PI3K/Akt signaling pathway, Fracture healin

    Effects of particle size and content of RDX on burning stability of RDX-based propellants

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    Abstract Particle size and content of RDX are the two main factors that affect the burning stability of RDX-based propellants. However, these effects and the corresponding mechanisms are still controversial. In this work, we investigated the physicochemical processes during burning and the corresponding mechanisms through the technologies of structure compactness analysis on the base of voidage measurement and theoretical interfacial area estimation, apparent burning rate measurement using closed vessel (CV) and extinguished burning surface characterization relying on interrupted closed vessel (ICV) and scanning electron microscope (SEM). The results indicate that the voidage increased with the increase of RDX content and particle size due to the increasing interfacial area and increasing interface gap size, respectively. The apparent burning rate increased with the increase of RDX particle size because of the decreasing RDX specific surface area on the burning surface, which could decrease the heat absorbing rates of the melting and evaporation processes of RDX in the condensed phase. Similarly, the apparent burning rate decreased with the increase of RDX content at pressures lower than around 55 MPa due to the increasing RDX specific surface area. Whereas, an opposite trend could be observed at pressures higher than around 55 MPa, which was attributed to the increasing heat feedback from the gas phase as the result of the increasing propellant energy. For propellants containing very coarse RDX particles, such as 97.8 and 199.4 μm average size, the apparent burning rate increased stably with a flat extinguished surface at pressures lower than around 30 MPa, while increased sharply above around 30 MPa with the extinguished surface becoming more and more rugged as the pressure increased. In addition, the turning degree of u-p curve increased with the increase of coarse RDX content and particle size, and could be reduced by improving the structure compactness

    From Data Fusion to Knowledge Fusion

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    The task of {\em data fusion} is to identify the true values of data items (eg, the true date of birth for {\em Tom Cruise}) among multiple observed values drawn from different sources (eg, Web sites) of varying (and unknown) reliability. A recent survey\cite{LDL+12} has provided a detailed comparison of various fusion methods on Deep Web data. In this paper, we study the applicability and limitations of different fusion techniques on a more challenging problem: {\em knowledge fusion}. Knowledge fusion identifies true subject-predicate-object triples extracted by multiple information extractors from multiple information sources. These extractors perform the tasks of entity linkage and schema alignment, thus introducing an additional source of noise that is quite different from that traditionally considered in the data fusion literature, which only focuses on factual errors in the original sources. We adapt state-of-the-art data fusion techniques and apply them to a knowledge base with 1.6B unique knowledge triples extracted by 12 extractors from over 1B Web pages, which is three orders of magnitude larger than the data sets used in previous data fusion papers. We show great promise of the data fusion approaches in solving the knowledge fusion problem, and suggest interesting research directions through a detailed error analysis of the methods.Comment: VLDB'201
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