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Dexiong Li,1,* Jing Xie,1,* Yubei Qiu,1,2 Sihui Zhang,1,3 Jiang Chen1,* 1School and Hospital of Stomatology, Fujian Medical University, Fuzhou, People’s Republic of China; 2Fujian Key Laboratory of Fujian College and University, Fujian Medical University, Fuzhou, People’s Republic of China; 3Institute of Stomatology & Research Center of Dental and Craniofacial Implants, School and Hospital of Stomatology, Fujian Medical University, Fuzhou, People’s Republic of China*These authors contributed equally to this workCorrespondence: Jiang Chen, School and Hospital of Stomatology, Fujian Medical University, Fuzhou, People’s Republic of China, Tel +86 591 83735488, Fax +86 591 83700838, Email jiangchen@fjmu.edu.cnBackground: Existing implant materials cannot meet the essential multifunctional requirements of repairing infected bone defects, such as antibacterial and osteogenesis abilities. A promising strategy to develop a versatile biomimicry composite of the natural bone structure may be accomplished by combining a multifunctional nanoparticle with an organic scaffold.Methods: In this study, a quaternary ammonium silane-modified mesoporous silica containing nano silver (Ag@QHMS) was successfully synthesized and further combined with silk fibroin (SF) to fabricate the multifunctional nano-reinforced scaffold (SF-Ag@QHMS) using the freeze-drying method. Furthermore, the antibacterial and osteogenic effects of this composite were evaluated in vitro and in vivo.Results: SF-Ag@QHMS inherited a three-dimensional porous structure (porosity rate: 91.90 ± 0.62%) and better mechanical characteristics (2.11 ± 0.06 kPa) than that of the SF scaffold (porosity rate: 91.62 ± 1.65%; mechanic strength: 2.02 ± 0.01 kPa). Simultaneously, the introduction of versatile nanoparticles has provided the composite with additional antibacterial ability against Porphyromonas gingivalis, which can be maintained for 15 days. Furthermore, the expression of osteogenic-associated factors was up-regulated due to the silver ions eluting from the composite scaffold. The in vivo micro-CT and histological results indicated that the new bone formation was not only localized around the border of the defect but also arose more in the center with the support of the composite.Conclusion: The multifunctional silver-loaded mesoporous silica enhanced the mechanical strength of the composite while also ensuring greater and sustained antibacterial and osteogenic properties, allowing the SF-Ag@QHMS composite to be used to repair infected bone defects.Keywords: silk fibroin, quaternary ammonium silane, multifunctional, nano-reinforce, composite scaffold

Background: Tongue squamous cell carcinoma (TSCC) is one of the most common types of oral cancer and has a poor prognosis owing to a limited understanding of its pathogenetic mechanisms. The purpose of this study was to explore and identify potential biomarkers in TSCC by integrated bioinformatics analysis.Methods: The RNA sequencing data, methylation data, and clinical characteristics of TSCC patients were downloaded from The Cancer Genome Atlas (TCGA), and then differentially expressed RNAs (DERNAs), including differentially expressed long noncoding RNAs (DElncRNAs) and differentially expressed messenger RNAs (DEmRNAs), were identified in TSCC by bioinformatics analysis. Subsequently, Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Hallmark pathway analyses were used to analyze the DERNAs. Univariate and multivariate Cox regression analyses were used to develop four-lncRNA and two-mRNA signatures and predict survival in TSCC patients. We established a risk model to predict the overall survival (OS) of TSCC patients based on the DERNAs with Kaplan–Meier analysis and the log-rank p test. Furthermore, weighted gene coexpression network analysis (WGCNA) was performed in Cytoscape, and a protein-protein interaction (PPI) network was established in the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database.Results: A total of 2,006 DEmRNAs and 1,001 DElncRNAs were found to be dysregulated in TSCC. A total of 417 DERNAs were used to construct the coexpression network, and the PPI network included 103 DEmRNAs. Univariate regression analysis of the DERNAs revealed 51 DElncRNAs and 90 DEmRNAs that were associated with OS in TSCC patients. Multivariate Cox regression analysis demonstrated that four of those lncRNAs (MGC32805, RP1-35C21.2, RP11-108K3.1, and RP11-109M17.2) and two mRNAs (CA9, GTSF1L) had significant prognostic value, and their cumulative risk score indicated that these four-lncRNA and two-mRNA signatures independently predicted OS in TSCC patients. Additionally, there was a positive correlation between the expression and methylation level of RP11-108K3.1, the OS significantly negatively correlated with hypermethylation and low expression of GTSF1L along with hypomethylation and high expression of CA9.Conclusions: The current findings provide novel insights into the molecular mechanisms of TSCC and identify four lncRNAs and two mRNAs that are potential biomarkers that may be independent prognostic signatures for TSCC diagnosis and treatment.

Treatments for infectious bone defects such as periodontitis require antibacterial and osteogenic differentiation capabilities. Nanotechnology has prompted the development of multifunctional material. In this research, we aim to synthesize a nanoparticle that can eliminate periodontal pathogenic microorganisms and simultaneously stimulate new bone tissue regeneration and mineralization. QAS-modified core-shell mesoporous silica containing Ag nanoparticles (Ag@QHMS) was successfully synthesized through the classic hydrothermal method and surface quaternary ammonium salt functionalization. The Ag@QHMS in vitro antibacterial activity was explored via coculture with Staphylococcus aureus, Escherichia coli, and Porphyromonas gingivalis biofilms. Bone mesenchymal stem cells (BMSCs) were selected for observing cytotoxicity, apoptosis, and osteogenic differentiation. Ag@QHMS showed a good sustained release profile of Ag+ and a QAS-grafted mesoporous structure. Compared with the single-contact antibacterial activity of QHMS, Ag@QHMS exhibited a more efficient and stable concentration-dependent antimicrobial efficacy; the minimum inhibitory concentration was within 100 μg/ml, which was below the BMSC biocompatibility concentration (200 μg/ml). Thus, apoptosis would not occur while promoting the increased expression of osteogenic-associated factors, such as runt-related transcription factor 2 (RUNX2), alkaline phosphatase (ALP), osteopontin (OPN), osteocalcin (OCN), bone sialoprotein (BSP), and collagen type 1 (COL-1). A safe concentration of particles can stimulate cell alkaline phosphatase and matrix calcium salt deposition. The dual antibacterial effect from the direct contact killing of QAS and the sustained release of Ag nanoparticles, along with the Ag-promoted osteogenic differentiation, had been verified and utilized in Ag@QHMS. This system demonstrates the potential for utilizing pluripotent biomaterials to treat complex lesions.

The integration of renewable energy sources in modern electric grids have drawn increasing attention nowadays. In order to effectively manage large-scale renewable energy sources and achieve flexible and efficient operation, the concept of microgrids have been proposed. Considering the nature of DC outputs in many distributed energy resources (DERs), DC microgrids have been extensively studied in the past years. Among the operational issues in DC microgrids, current sharing issues have become an important topic since it is highly relevant to the operation of DC microgrids. By adopting a proper design of current sharing strategy in DC microgrids, the current rating violations in each interface converter can be successfully avoided. In this paper, a looped-chain-based active current sharing strategy is proposed to realize high accuracy current sharing in DC microgrids. In particular, the output current is shared between the neighboring interface converters. Hence, following a clockwise or counter-clockwise order, a looped-chain-based control diagram can be established to share the reference value of the output current. A final status in the whole DC microgrid is that the output current of every interface converter is equalized. Hence, the desired current sharing objective can be satisfied. A MATLAB simulation model is established to verify the proposed looped-chain-based active current sharing strategy in DC microgrids.

Aiming at the axial imbalance force when the traditional axial piston motor works, the force balanced axial piston motor utilized the concept of double stator to improve the structure of the traditional axial piston motor. Because of the special structure, the motor can not only achieve the axial force balance, but also output a variety of torque and speed. The working efficiency of the motor was an important indicator for evaluating the performance of the motor. Therefore, the power loss and leakage of the motor were analyzed in detail, and the prototype was tested. The experimental results showed that: (1) When the corresponding two single motors in the motor worked at the same time, theoretically, the leakage between the distribution cylinder and the cylinder accounts for the largest percentage of total leakage, reaching 56%. When the whole motor worked normally, the total leakage reaches 9.55L/min theoretically, and the leakage between the plunger and the plunger hole accounts for the largest percentage of the total leakage, which is 44% of the total leakage, and the distribution cylinder and cylinder the percentage of leakage between bodies has decreased, but its specific leakage has not changed. (2) The volumetric efficiency of the motor decreased as the pressure at the inlet of the motor increased, and the mechanical efficiency and overall efficiency increased accordingly. (3) When the motor inlet pressure was the same, the volumetric efficiency of two single motors at the same time was lower than the volumetric efficiency of the entire motor.

Due to the randomicity of wind power energy, the voltage flicker of power grid will occur after large-scale wind power is connected with power grid. The factors such as wind regime, characteristics of wind power generators and system condition of power gird impact the voltage flicker caused by wind power generation. Based on the IEC(International Electrotechnical Commission) Standard, this paper analyzes the features of power grid and characteristics of wind power generators, builds a virtual grid model in Matlab/Simulink. The texts showed that the improved flicker measurement circuit can accurately measure the value of flicker, and improve the flicker measurement accuracy.

Grid is attracting more and more attentions by its massive computational capacity. Tools like Globus Toolkit and MPICH-G2 have been developed to help scientists to facilitate their researches. As a Grid-enabled implementation of MPI, MPICH-G2 helps developers to port parallel applications to cross-domain environment. Since the current computationally-intensive parallel applications, especially long-running tasks, require high availability as well as high performance computing platform, dynamic job migration in Grid environment has became an essential issue. In this study, we present a dynamic job migration enabled MPICH-G2 version, MPICH-G-DM. We use Virtual Job Model (VJM) to reserve resources for the migrating jobs in advance to improve the efficiency of the system. An Asynchronous Migration Protocol (AMP) is proposed to enable the migrating sub jobs to checkpoint/restart and update their new addresses concurrently without a global synchronization. In order to reduce the communicating overhead of job migration, MPICH-G-DM minimized the number of control messages among domains to O(N). Experiment results show that MPICH-G-DM is effective and reliable.