No abstract

Bone morphogenetic protein 2 (BMP-2) is one of the most important factors for bone tissue formation. A number of BMP-2 related small molecule bioactive peptides have been designed and shown to be equally effective in osteogenic activity. In this report, we synthesized a novel BMP-2related peptide (designated P28) and designed a delivery system to regulate the controlled release of P28 from true bone ceramics (TBC) combined with an enlarged pore hollow mesoporous silica nanoparticles (HMSNs) composite scaffold. An in vitro release showed that the release of P28 from the TBC/ HMSN scaffold was slower than that from the TBC scaffold. An in vitro cell experiment of the TBC/HMSN/P28 scaffold was tested with MC3T3-E1 cells in comparison to TBC, TBC/HMSN, and TBC/P28 scaffolds. Our results demonstrated that the TBC/HMSN/P28 scaffold had better effects on promoting proliferation and osteogenic differentiation of MC3T3-E1 cells than TBC, TBC/HMSN, and TBC/P28 scaffolds. After four kinds of scaffolds were implanted into a rabbit radius critical bone defect for 6 and 12 weeks, the radiographic and histological examination indicated that this osteogenic delivery system TBC/HMSN/P28 scaffold effectively induced bone regeneration in vivo. Therefore, the TBC/ HMSN/P28 scaffold can promote proliferation and osteogenic differentiation of MC3T3-E1 cells in vitro and new bone tissue generation in vivo. This study provides a promising scaffold for bone tissue engineering and regenerative medicine.

No abstract

The results from this study suggest that optical spectroscopy has the potential to detect intravascular needle placement, which may in turn increase the safety of nerve blocks.

The emerging trend of social information processing has resulted in Web users' increased reliance on usergenerated content contributed by others for information searching and decision making. Rating scores, a form of user-generated content contributed by reviewers in online rating systems, allow users to leverage others' opinions in the evaluation of objects. In this article, we focus on the problem of summarizing the rating scores given to an object into an overall score that reflects the object's quality. We observe that the existing approaches for summarizing scores largely ignores the effect of reviewers exercising different standards in assigning scores. Instead of treating all reviewers as equals, our approach models the leniency of reviewers, which refers to the tendency of a reviewer to assign higher scores than other coreviewers. Our approach is underlined by two insights: (1) The leniency of a reviewer depends not only on how the reviewer rates objects, but also on how other reviewers rate those objects and (2) The leniency of a reviewer and the quality of rated objects are mutually dependent. We develop the leniency-aware quality, or LQ model, which solves leniency and quality simultaneously. We introduce both an exact and a ranked solution to the model. Experiments on real-life and synthetic datasets show that LQ is more effective than comparable approaches. LQ is also shown to perform consistently better under different parameter settings.