Periosteum Mimetic Coating on Structural Bone Allografts via Electrospray Deposition Enhances Repair and Reconstruction of Segmental Defects.

Structural bone allograft transplantation remains one of the common strategies for repair and reconstruction of large bone defects. Due to the loss of periosteum that covers the outer surface of the cortical bone, the healing and incorporation of allografts is extremely slow and limited. To enhance the biological performance of allografts, herein, we report a novel and simple approach for engineering a periosteum mimetic coating on the surface of structural bone allografts via polymer-mediated electrospray deposition. This approach enables the coating on allografts with precisely controlled composition and thickness. In addition, the periosteum mimetic coating can be tailored to achieve desired drug release profiles by making use of an appropriate biodegradable polymer or polymer blend. The efficacy study in a murine segmental femoral bone defect model demonstrates that the allograft coating composed of poly(lactic-co-glycolic acid) and bone morphogenetic protein-2 mimicking peptide significantly improves allograft healing as evidenced by decreased fibrotic tissue formation, increased periosteal bone formation, and enhanced osseointegration. Taken together, this study provides a platform technology for engineering a periosteum mimetic coating which can greatly promote bone allograft healing. This technology could eventually result in an off-the-shelf and multifunctional structural bone allograft for highly effective repair and reconstruction of large segmental bone defects. The technology can also be used to ameliorate the performance of other medical implants by modifying their surfaces.

Visual Analysis of Collective Anomalies Using Faceted High-Order Correlation Graphs.

Successfully detecting, analyzing, and reasoning about collective anomalies is important for many real-life application domains (e.g., intrusion detection, fraud analysis, software security). The primary challenges to achieving this goal include the overwhelming number of low-risk events and their multimodal relationships, the diversity of collective anomalies by various data and anomaly types, and the difficulty in incorporating the domain knowledge of experts. In this paper, we propose the novel concept of the faceted High-Order Correlation Graph (HOCG). Compared with previous, low-order correlation graphs, HOCG achieves better user interactivity, computational scalability, and domain generality through synthesizing heterogeneous types of objects, their anomalies, and the multimodal relationships, all in a single graph. We design elaborate visual metaphors, interaction models, and the coordinated multiple view based interface to allow users to fully unleash the visual analytics power of the HOCG. We conduct case studies for three application domains and collect feedback from domain experts who apply our method to these scenarios. The results demonstrate the effectiveness of the HOCG in the overview of point anomalies, the detection of collective anomalies, and the reasoning process of root cause analyses.

JamCatcher: A Mobile Jammer Localization Scheme for Advanced Metering Infrastructure in Smart Grid.

As the core component of the smart grid, advanced metering infrastructure (AMI) is responsible for automated billing, demand response, load forecasting, management, etc. The jamming attack poses a serious threat to the AMI communication networks, especially the neighborhood area network where wireless technologies are widely adopted to connect a tremendous amount of smart meters. An attacker can easily build a jammer using a software-defined radio and jam the wireless communications between smart meters and local controllers, causing failures of on-line monitoring and state estimation. Accurate jammer localization is the first step for defending AMIs against jamming attacks. In this paper, we propose JamCatcher, a mobile jammer localization scheme for defending the AMI. Unlike existing jammer localization schemes, which only consider stationary jammers and usually require a high density of anchor nodes, the proposed scheme utilizes a tracker and can localize a mobile jammer with sparse anchor nodes. The time delay of data transmission is also considered, and the jammer localization process is divided into two stages, i.e., far-field chasing stage and near-field capturing stage. Different localization algorithms are developed for each stage. The proposed method has been tested with data from both simulation and real-world experiment. The results demonstrate that JamCatcher outperforms existing jammer localization algorithms with a limited number of anchor nodes in the AMI scenario.

Sal B attenuates rat hepatocytes injury induced by hypoxia/reoxygenation via modulation of SIRT1/NF-κB/p53 pathway / 中国药理学通报

Aim To investigate the effect of salvianolic acid B(Sal B) on the attenuation of rat hepatocyte in-jury induced by hypoxia/reoxygenation(H/R) and its possible molecular mechanism. Methods Rat hepato-cytes BRL-3A were cultured in vitro. H/R injury mod-el was established and then BRL-3A cells were pretrea-ted with Sal B. The viability of cells was measured by CCK-8 assay;the expression of ALT and AST was de-tected by microplate assay; the levels of TNF-α and IL-1β were determined by ELISA; the apoptosis was detected by flow cytometry;the protein and mRNA lev-els of SIRT1, NF-κB p65, p53, Bax and Bcl-2 were measured by Western blot and qPCR. Results H/R intervention decreased the viability and increased the apoptosis of cells;the production of ALT, AST, TNF-α and IL-1β was elevated;the protein and mRNA lev-els of SIRT1, Bcl-2 were reduced, but the levels of NF-κB p65, p53 and Bax increased. After pretreated with Sal B, the viability of cells increased while the apoptosis decreased; the expression of ALT, AST, TNF-α and IL-1β was inhibited;moreover,the protein and mRNA levels of SIRT1,Bcl-2 were enhanced,and the levels of NF-κB p65, p53 and Bax decreased sig-nificantly. Conclusion Sal B may attenuate rat hepa-tocyte injury induced by H/R via the SIRT1/NF-κB/p53 pathway.

Population-Stratified Analysis of Bone Mineral Density Distribution in Cervical and Lumbar Vertebrae of Chinese from Quantitative Computed Tomography

OBJECTIVE: To investigate the bone mineral density (BMD) of cervical vertebrae in a population-stratified manner and correlate with that of the lumbar vertebrae. MATERIALS AND METHODS: Five hundred and ninety-eight healthy volunteers (254 males, 344 females), ranging from 20 to 64 years of age, were recruited for volumetric BMD (vBMD) measurements by quantitative computed tomography. Basic information (age, height, weight, waistline, and hipline), and vBMD of the cervical and lumbar vertebrae (C2-7 and L2-4) were recorded. Comparisons among sex, age groups and different levels of vertebrae were analyzed using analysis of variance. Linear regression was performed for relevance of different vertebral levels. RESULTS: The vBMD of cervical and lumbar vertebrae was higher in females than males in each age group. The vBMD of the cervical and lumbar vertebrae in males and the vBMD of lumbar vertebrae in females decreased with aging. In each age group, the vBMD of the cervical vertebrae was higher than that of the lumbar vertebrae with gradual decreases from C2 to C7 except for C3; moreover, the vBMD of C6 and C7 was significantly different from that of C2-5. Correlations of vBMD among different cervical vertebrae (females: r = 0.62-0.94; males: r = 0.63-0.94) and lumbar vertebrae (males: r = 0.93-0.98; females: r = 0.82-0.97) were statistically significant at each age group. CONCLUSION: The present study provided normative data of cervical vertebrae in an age- and sex-stratified manner. Sex differences in vBMD prominently vary with age, which can be helpful to design a more comprehensive pre-operative surgical plan.