D-RADA16-RGD-Reinforced Nano-Hydroxyapatite/Polyamide 66 Ternary Biomaterial for Bone Formation

Bo Qiao,Bin He,Ao Zhou,Yuling Li,Xiaojun Chen,Qiming Yang,Beike Chen,Bo Qiao,Dianming Jiang 한국조직공학과 재생의학회 2019 조직공학과 재생의학 Vol.16 No.2

BACKGROUND: Nano-hydroxyapatite/polyamide 66 (nHA/PA66) is a composite used widely in the repair of bone defects. However, this material is insufficient bioactivity. In contrast, D-RADA16-RGD self-assembling peptide (DRADA16- RGD sequence containing all D-amino acids is Ac-RADARADARADARADARGDS-CONH2) shows admirable bioactivity for both cell culture and bone regeneration. Here, we describe the fabrication of a favorable biomaterial material (nHA/PA66/D-RADA16-RGD). METHODS: Proteinase K and circular dichroism spectroscopy were employed to test the stability and secondary structural properties of peptide D-RADA16-RGD respectively. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to characterize the surface of these materials. Confocal laser scanning (CLS), cell counting kit-8 tests (CCK-8), alizarin red S staining, cell immunofluorescence analysis and Western blotting were involved in vitro. Also biosafety and bioactivity of them have been evaluated in vivo. RESULTS: Proteinase K and circular dichroism spectroscopy demonstrated that D-RADA16-RGD in nHA/PA66 was able to form stable-sheet secondary structure. SEM and TEM showed that the D-RADA16-RGD material was 7–33 nm in width and 130–600 nm in length, and the interwoven pore size ranged from 40 to 200 nm. CLS suggests that cells in nHA/PA66/ D-RADA16-RGD group were linked to adjacent cells with more actin filaments. CCK-8 analysis showed that nHA/PA66/ D-RADA16-RGD revealed good biocompatibility. The results of Alizarin-red S staining and Western blotting as well as vivo osteogenesis suggest nHA/PA66/D-RADA16-RGD exhibits better bioactivity. CONCLUSION: This study demonstrates that our nHA/PA66/D-RADA16-RGD composite exhibits reasonable mechanical properties, biocompatibility and bioactivity with promotion of bone formation.

An Offloading Scheduling Strategy with Minimized Power Overhead for Internet of Vehicles Based on Mobile Edge Computing

( Bo He ),( Tianzhang Li ) 한국정보처리학회 2021 Journal of information processing systems Vol.17 No.3

By distributing computing tasks among devices at the edge of networks, edge computing uses virtualization, distributed computing and parallel computing technologies to enable users dynamically obtain computing power, storage space and other services as needed. Applying edge computing architectures to Internet of Vehicles can effectively alleviate the contradiction among the large amount of computing, low delayed vehicle applications, and the limited and uneven resource distribution of vehicles. In this paper, a predictive offloading strategy based on the MEC load state is proposed, which not only considers reducing the delay of calculation results by the RSU multi-hop backhaul, but also reduces the queuing time of tasks at MEC servers. Firstly, the delay factor and the energy consumption factor are introduced according to the characteristics of tasks, and the cost of local execution and offloading to MEC servers for execution are defined. Then, from the perspective of vehicles, the delay preference factor and the energy consumption preference factor are introduced to define the cost of executing a computing task for another computing task. Furthermore, a mathematical optimization model for minimizing the power overhead is constructed with the constraints of time delay and power consumption. Additionally, the simulated annealing algorithm is utilized to solve the optimization model. The simulation results show that this strategy can effectively reduce the system power consumption by shortening the task execution delay. Finally, we can choose whether to offload computing tasks to MEC server for execution according to the size of two costs. This strategy not only meets the requirements of time delay and energy consumption, but also ensures the lowest cost.

Coupled Discrete Crack and Porous Media Model for Hydraulic Fractures using the XFEM

Bo He,Xiaoying Zhuang 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.3

A hydromechanical model for investigating fluid flow in the fractured porous media is presented in this study. The hydromechanical coupling equations are derived from the mass and momentum balance equation for the saturated porous media. The extended finite element method is employed to model the discontinuity for fluid flow and cracks inside the porous media. The Newton-Raphson method is utilized for solving the nonlinear coupling equation with an implicit time integration scheme. Finally, examples are presented to demonstrate the effectiveness of the presented model. Fracture propagation in the porous media under the influence of the preexisted pressurized zone is also studied. It is found that the cracks and preexisted pressurized region have a significant impact on the fluid flow and deformation patterns.

Development and Application of Advanced Tribological Testing Technology

Bo He 한국트라이볼로지학회 2019 한국트라이볼로지학회 학술대회 Vol.2019 No.4

Influence Analysis of Leader Information with Application to Formation Control of Multi-agent Systems

Bo He,Feng Gao 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.12

Considering the problem that does all the information have the same effect on the control performance of multi-agent system, this paper analyzes the influence of leader state on closed loop dynamics of formation theoretically. For the first time, it is proved that the leader information can mask out the effect of others and the closed loop dynamics of formation is equivalent to the leader follower topology if all followers can receive the leader information and others. Based on this new foundation, an estimator for leader state is designed using the sliding mode control theory. This estimator is independent of the dynamical functions of agents and only the minimum eigenvalue of topological matrix is required to ensure the convergence of estimation error even when leader runs dynamically. Several simulations have been conducted to further validate the correctness of this new theoretical foundation and the effectiveness of the estimator based formation control strategy.

Changing patterns of Serum CEA and CA199 for Evaluating the Response to First-line Chemotherapy in Patients with Advanced Gastric Adenocarcinoma

He, Bo,Zhang, Hui-Qing,Xiong, Shu-Ping,Lu, Shan,Wan, Yi-Ye,Song, Rong-Feng Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.8

Background: This study was designed to investigate the value of CEA and CA199 in predicting the treatment response to palliative chemotherapy for advanced gastric cancer. Materials and Methods: We studied 189 patients with advanced gastric cancer who received first-line chemotherapy, measured the serum CEA and CA199 levels, used RECIST1.1 as the gold standard and analyzed the value of CEA and CA199 levels changes in predicting the treatment efficacy of chemotherapy. Results: Among the 189 patients, 80 and 94 cases had increases of baseline CEA (${\geq}5ng/ml$) and CA199 levels (${\geq}27U/ml$), respectively. After two cycles of chemotherapy, 42.9% patients showed partial remission, 33.3% stable disease, and 23.8% progressive disease. The area under the ROC curve (AUC) for CEA and CA199 reduction in predicting effective chemotherapy were 0.828 (95%CI 0.740-0.916) and 0.897 (95%CI 0.832-0.961). The AUCs for CEA and CA199 increase in predicting progression after chemotherapy were 0.923 (95%CI 0.865-0.980) and 0.896 (95%CI 0.834-0.959), respectively. Patients who exhibited a CEA decline ${\geq}24%$ and a CA199 decline ${\geq}29%$ had significantly longer PFS (log rank p=0.001, p<0.001). With the exception of patients who presented with abnormal levels after chemotherapy, changes of CEA and CA199 levels had limited value for evaluating the chemotherapy efficacy in patients with normal baseline tumor markers. Conclusions: Changes in serum CEA and CA199 levels can accurately predict the efficacy of first-line chemotherapy in advanced gastric cancer. Patients with levels decreasing beyond the optimal critical values after chemotherapy have longer PFS.

Effect of $MoS_2$-Based Composite Coatings on Tribological Behavior and Efficiency of Gear

He, Hui-Bo,Li, Hua-Ying,Xu, Zhe-Zhu,Kim, Dong-Uk,Lyu, Sung-Ki 한국정밀공학회 2010 International Journal of Precision Engineering and Vol.11 No.6

$MoS_2$-based Ti composite coatings were deposited on the SCM420 alloy and gears using an RF magnetron sputtering (RFMS) system. While $MoS_2$ coating had been coated on the silicon substrate. The coatings structures were compared to each other to find the effect of Ti. The composite coatings have been tested in a ball-on-disk tribometer to investigate tribological behavior at various conditions. The scratch test was conducted to characterize adhesion force between composite coatings and substrates. The structure of the coatings has been extensively studied by a variety of techniques, including optical microscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM), etc. The composite coatings were also applied to the gears of a reduction gearbox. The efficiency of uncoated and $MoS_2$-based Ti coated gear was measured and compared at various input rotating speed under absorption oil film condition. It was found that the efficiency of gear had significantly improved after $MoS_2$-based Ti composite coatings deposition.

Nanosheets of copolymerized ionic liquid-based polyelectrolyte complexes regulated at oil–water interface and their emulsification capability

He Zhang,Jun Bo Zhang,Qing Bo Meng,Wei Guo,Ming Yang,Shuyao Wu,Qiong Wu,Daliang Liu,Xi-Ming Song 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.97 No.-

The emulsification by polyelectrolyte complexes is easy to handle, and could be considered as an effectivestrategy for introducing functional materials to liquid–liquid interfaces, but the related studies are stillinsufficient. Herein, a kind of copolymerized ionic liquid (PIL-co-PVIm) which is synthesized from 1-vinyl-3-ethylimidazolium bromide and 1-vinylimidazole, are used as polycation to form polyelectrolytecomplexes type Pickering emulsifiers with sodium alginate, poly(sodium 4-styrenesulfonate) and poly(acrylic acid) sodium salt respectively as polyanion. For toluene-water emulsion systems andhydrophobic ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIm]PF6)-watersystem, the polyelectrolyte complexes formed by PIL-co-PVIm and sodium alginate or poly (sodium4-styrenesulfonate) showed best emulsification capability. The emulsions stabilized by the polyelectro-lyte complexes at stoichiometric ratio are relatively less stable compared to non-stoichiometriccomplexes, while PIL-co-PVIm without complexation has no emulsification capability. The polyelectro-lyte complexes based on homopolymerized PIL give an unsatisfied emulsification capability, while theemulsification performance could be remarkably improved by copolymerizing ionic liquids with theuncharged comonomer, but excessive contents of the uncharged unit make the polyelectrolytecomplexes less interface active. The sheet-like PECs are formed in aqueous dispersions, and theirthickness is remarkably reduced at oil–water interface after emulsification, approximately ranging from200 nm to 10 nm by manipulating the polyanion.

Shape-coded silica nanotubes for multiplexed bioassay: rapid and reliable magnetic decoding protocols.

He, Bo,Kim, Sung Kyoung,Son, Sang Jun,Lee, Sang Bok Future Medicine Ltd 2010 Nanomedicine Vol.5 No.1

<P>Aims: The recent development of 1D barcode arrays has proved their capabilities to be applicable to highly multiplexed bioassays. This article introduces two magnetic decoding protocols for suspension arrays of shape-coded silica nanotubes to process multiplexed assays rapidly and easily, which will benefit the minimization and automation of the arrays. Methods: In the first protocol, the magnetic nanocrystals are incorporated into the inner voids of barcoded silica nanotubes in order to give the nanotubes magnetic properties. The second protocol is performed by trapping the barcoded silica nanotubes onto streptavidin-modified magnetic beads. Results: The rapid and easy decoding process was demonstrated by applying the above two protocols to multiplexed assays, resulting in high selectivity. Furthermore, the magnetic bead-trapped barcode nanotubes provided a great opportunity to exclude the use of dye molecules in multiplexed assays by using barcode nanotubes as signals. Conclusion: The rapid and easy manipulation of encoded carriers using magnetic properties could be used to develop promising suspension arrays for portable bioassays.</P>

A New Automatic Target Recognition Scheme Based on Model Simulation and Structured Learning

Bo Sun,Xuewen Wu,Jun He 보안공학연구지원센터(IJSIP) 2014 International Journal of Signal Processing, Image Vol.7 No.6

In recent years, more and more researchers' attention has been drawn to the sparse representation-based classification (SRC) method and its application in image analysis and pattern recognition, due to its good characteristics of high recognition rate, robustness to corruption and occlusion, and little dependence on the features selection etc. However, sufficient training samples are always required by the sparse representation method for the effective recognition. In practical applications, it is generally difficult to obtain sufficient training samples of the test targets, especially non-cooperative targets. So the key issues in the effective automatic target recognition (ATR) based on the sparse representation are to obtain sufficient training samples in different scales, angles, and different illumination conditions, and to construct an overcomplete dictionary with discriminative ability. In this paper, a novel sparse representation-based scheme is proposed for the automatic target recognition in the real environment, in which the training samples are drawn from the simulation models of real targets and the overcomplete dictionary is trained using structured sparse learning method. The experimental results show that the proposed method is effective for the automatic target recognition in the practical application, especially, where the desired features of the sparse representation method are kept.