Calreticulin protects the HT22 hippocampal neurons from injury induced by hypoxia

Zhaoping Wang,Mei Yang,Jian Xue,Yanjun Chong 대한독성 유전단백체 학회 2018 Molecular & cellular toxicology Vol.14 No.1

The purpose of this study was to evaluate the role of calreticulin (CRT) in the hypoxia-induced injury of HT22 cells through over-expression and knockdown of CRT. Cells were transfected with pcDNA3.1, pcDNA3.1 carrying full length CRT (pcDNA-CRT), small interfering RNA targeting CRT (si-CRT) or its negative control (siNC). Then, cell viability and apoptosis were respectively detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was performed to evaluate mRNA expression level of CRT. Western blotting was performed to determine the protein expression levels of CRT and apoptosis related proteins. Results showed CRT was successfully overexpressed by transfection of pcDNA-CRT (P<0.05) and silenced by transfection of si-CRT(P<0.05). CRT over-expression could promote the HT22 cell proliferation (P<0.01 or P<0.001) and inhibit hypoxia-induced apoptosis(P<0.05). Western blotting illustrated up-regulation of CRT increased the expression of Bcl2 (P<0.01) but decreased the expressions of cytochrome c (P<0.01), active caspase 3 (P<0.001) and active caspase 9 (P<0.05) under hypoxia treatment. The effect of CRT knockdown was opposite to CRT over-expression. We speculated that CRT might regulate the expression of apoptosis related factors such as cytochrome-c, caspase 3, caspase 9 and Bcl-2, protecting the HT22 cells from hypoxia-induced injury. These results will provide the theory basis for the clinical treatment of cerebral hypoxia-induced injury.

Intelligent identification of the flow regimes of two-component particles in a fluidized bed with the optimized fuzzy c-means clustering algorithm

Zhaoping Zhong,Heng Wang,Xiaoyi Wang,Feihong Guo 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.5

Flow regime identification is important in the application of fluidized beds. This paper provides a method for deciding flow regime number by objective criterion. The optimized fuzzy c-means clustering algorithm was used to cluster the flow regime classification of two-component particles in a fluidized bed. The genetic algorithm was applied to optimize the initial center clusters of fuzzy c-means clustering. Hilbert-Huang transform was applied to analyze pressure fluctuation signals and extract the characteristic parameters. Three clusters were found and respectively ascribed to three flow regimes: bubbling bed, slugging bed, and turbulent bed. A multilayer neural network was used to train and test the identification system of the flow regimes. The identification accuracies of bubbling bed, slugging bed, and turbulent bed can reach 91.67%, 92.85%, and 91.30%, respectively.

Simulation of large biomass pellets in fluidized bed by DEM-CFD

Zhaoping Zhong,Lingli Zhu,Heng Wang,Zeyu Wang 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.10

An improved numerical model was proposed to solve the problem that the traditional DEM-CFD (Discrete element method-computational fluid dynamics) method was not suitable for the flow simulation of large particles. In the improved model, the large particle was regarded as an agglomerate of many small fictitious spheres. Herein, the drag force between gas and large pellets was assumed as a combined effect of that between gas and fictitious spheres by volume penalty method. Based on the proposed model, the flow of the mixtures of large biomass pellets and quartz sands in fluidized bed was simulated. It shows that the existence of the biomass pellets has a great impact on the flow field. The flow patterns and pressure drops under different working conditions in simulation results have a good agreement with that in experimental results partially, which also tests the proposed model.

Application of Hilbert-Huang transformation in fluidized bed with two-component (biomass particles and quartz sands) mixing flow

Xiaoyi Wang,Zhaoping Zhong,Heng Wang,Zeyu Wang 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.1

Hilbert-Huang transformation was used to investigate the nonlinear characteristics of two-component (bio-mass particles and quartz sand) mixing flow by analyzing the pressure fluctuation signals in fluidized bed. Based onempirical mode decomposition (EMD), the Hilbert-Huang spectra in bubbling and slugging flow patterns were ob-tained and analyzed. In bubbling flow pattern, compared with one-component (quartz sand) flow, the energy of two-component mixing flow is lower in 0-5 Hz and higher in 40-50 Hz. In slugging flow pattern, the energy in pressurefluctuation mainly lies in 0-5 Hz. and the effect of biomass particles on the Hilbert-Huang spectrum is not very obvi-ous. Compared with traditional power spectral density (PSD), HHT is much more suitable for investigating pressurefluctuation signals in fluidized beds.

Microscopic flow characteristics in fluidized bed of cylinder-shaped particles

Chunhua Wang,Zhaoping Zhong,Xiaoyi Wang 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.12

IBM (Immersed boundary method) and DEM (Discrete element method) coupling method were used to simulate the flow of cylinder-shaped particles in a fluidized bed. The greatest advantage of IBM-DEM is that it can reveal the microscopic characteristics of dense-phase gas-particle flow in Cartesian grids. Large cylinder-shaped particles are very difficult to fluidize, and slugging flow can be observed even if the static bed height is low. The gas flow field around the particle in fluidized bed is analyzed, and the formation and development of vortex behind the particle is affected obviously by the neighboring particles. Particle trajectory is obtained, and the effect of gas phase on particle rotation becomes active as particle size increases. Compared with the experimental results, the gas-solid force in simulation results is higher. This calculation error may be reduced by decreasing the grid size.

Flow regime recognition in the spouted bed based on Hilbert-Huang transformation

Wang Chunhua,Zhong Zhaoping,Li Rui 한국화학공학회 2011 Korean Journal of Chemical Engineering Vol.28 No.1

Empirical mode decomposition has been used to decompose the pressure fluctuation signals in the spouted bed into several intrinsic mode functions, and these modes were transformed from the time domain into the frequency domain by Hilbert transformation. According to the characteristic parameters extracted from these modes, flow regimes were recognized by RBF neural network, and parameters in RBF neural network were optimized by adaptive genetic algorithm. The recognition accuracy of packed bed, spouted bed, bubbly fluidized bed and slugging bed can reach 90%,85%, 85%, 95%, respectively.

Experimental Studies on Bond Performance of BFRP Bars Reinforced Coral Aggregate Concrete

Lei Wang,Zhaoping Song,Jin Yi,Jiayi Li,Feng Fu,Kai Qian 한국콘크리트학회 2019 International Journal of Concrete Structures and M Vol.13 No.7

Basalt fiber reinforced polymer (BFRP) rebars reinforced coral aggregate concrete is a new type of concrete used in ocean engineering. In order to investigate the bond performance between BFRP rebars and coral concrete, 30 pullout tests were carried out in 10 groups with different diameters of BFRP rebars, bonding lengths and strength of the coral concrete. The results show that good bonding between BFRP rebars and coral concrete were achieved. The main failure modes can be categorized as BFRP rebars pull out destruction, splitting failure of coral concrete and BFRP rebars fracture. The bond slip ( τ -s ) curves of the BFRP rebars and coral concrete were obtained during the tests. It was found to be similar to the common concrete using fiber reinforced polymer (FRP) bars. The bond-slip relation can be roughly divided into micro-slip phase, slip phase, decline phase, and the residual stress stage. The bond between BFRP rebars and coral concrete increases with the increase of the bond length and diameter of BFRP rebars, but the average bond stress will decrease. Moreover, increasing the strength of coral concrete is effective to improve the bond performance of BFRP rebars. In this paper, the continuous bond slip model (Gao et al. in J Zhengzhou Univ 23:1.5, 2002) was used to represent the τ -s constitutive relationship of BFRP rebars and coral concrete. The analysis show that the proposed model has a high degree of accuracy in representing τ -s curve of BFRP rebars and coral concrete.

An overlay-based service architecture for distributed video surveillance system

Xuesong Cao,Zhaoping Wang,Ruimin Hu Jun Chen 보안공학연구지원센터 2008 International Journal of Software Engineering and Vol.2 No.2

In this paper, a service architecture based on overlay network was presented. The architecture was designed to build a novel distributed video surveillance system, called as Etouch. In the model, the system is divided into three layers: underlying network layer (UNL) , overlay service network layer (OSNL) and application layer (AL). OSNL is composed of many intelligent overlay nodes mapped by underlying network layer. Overlay nodes provide all kinds of media service for surveillance application in AL. OSNL allows media service composition of distributed stream processing applications dynamically. And a load balance of QoS-aware service composition algorithm (LBQSC) is employed to satisfy their end-to-end QoS demands. Large-scale experimental results demonstrate the scalability, efficiency and performance of the E-touch system.

DeNOx performance and characteristic study for transition metals doped iron based catalysts

Lin Zhu,Zhaoping Zhong,Han Yang,Chunhua Wang,LixiaWang 한국화학공학회 2017 Korean Journal of Chemical Engineering Vol.34 No.4

Novel, environmentally-benign catalysts for selective catalytic reduction of NOx were prepared by citric method through introducing transition metal elements (Ce, Cu and Co) into iron oxide. The physical-chemical properties of different catalysts were investigated by the characterization technologies like N2-physisorption, XRD, NH3/NOTPD and H2-TPR. The results indicated that the introduction of transition metal elements increased the specific surface area and adsorption ability for reactants (NH3 and NOx). The redox capacity for the doped catalysts was improved at the same time. These characteristics all contributed to the improvement of catalytic performance. The CoFeOx catalyst exhibited the widest temperature window for SCR reaction, and the CeFeOx catalyst showed the most obvious decline of NOx conversion with the elevation of temperature above 250 oC. Water vapor inhibited the SCR activity at low temperatures and relieved the decline of NOx conversion at higher temperatures. Meanwhile, the formation of N2O was inhibited. The pretreatment of SO2 leaded to the sulfation of the active species for different catalysts. The decline of redox capacity and the reduction of active nitrate adsorbed species accounted for the serious loss of SCR activity at low temperatures. The abundant surface acid sites brought by the sulfation process might be the main reason for good SCR activity in the medium temperature range.

Fabrication of Transparent Cellulose Fiber Paper by Sequential Treatment of Cationic Cellulose Nanofibers and Polyvinylpyrrolidone

Furong Xin,Huili Wang,Feixiang Guan,Guodong Li,Zhaoping Song,Dehai Yu,Wenxia Liu 한국섬유공학회 2020 Fibers and polymers Vol.21 No.9

Paper-based material is receiving more and more attention as an alternative of plastics in flexible electronics. However, conventional paper made of cellulose fibers is opaque owing to its micron-sized void space among fibers. Herein,cellulose fiber paper was changed into transparent paper by sequentially coating cationic cellulose nanofibers (CNFs) andpolyvinylpyrrolidone (PVP). The morphology, transparency, thermal and mechanical properties were analyzed. The resultsshow that the coating of CNFs reduces the micron-sized void space in the cellulose fiber paper, favoring the furtherimprovement on the transparency of paper by coating PVP. By optimizing the coating amount of CNFs and PVP, atransparent paper with a transmittance of 88.5 % at 550 nm is obtained. The as-prepared transparent paper also showsimproved thermal stability, slightly increased tensile strength and significantly enhanced deformation resistance. It was apotential candidate of flexible electronic substrates.