Interaction between Brucella melitensis 16M and small ubiquitin-related modifier 1 and E2 conjugating enzyme 9 in mouse RAW264.7 macrophages

Jihai Yi,Yueli Wang,Qifeng Li,Huan Zhang,Zhiran Shao,XiaoYu Deng,Jinke He,Chencheng Xiao,Zhen Wang,Yong Wang,Chuangfu Chen 대한수의학회 2019 Journal of Veterinary Science Vol.20 No.5

Brucella is an intracellular pathogen that invades a host and settles in its immune cells; however, the mechanism of its intracellular survival is unclear. Modification of small ubiquitin-related modifier (SUMO) occurs in many cellular activities. E2 conjugating enzyme 9 (Ubc9) is the only reported ubiquitin-conjugating enzyme that links the SUMO molecule with a target protein. Brucella's intracellular survival mechanism has not been studied with respect to SUMO-related proteins and Ubc9. Therefore, to investigate the relationship between Brucella melitensis 16M and SUMO, we constructed plasmids and cells lines suitable for overexpression and knockdown of SUMO1 and Ubc9 genes. Brucella 16M activated SUMO1/Ubc9 expression in a time-dependent manner, and Brucella 16M intracellular survival was inhibited by SUMO1/Ubc9 overexpression and promoted by SUMO1/Ubc9 depletion. In macrophages, Brucella 16M-dependent apoptosis and immune factors were induced by SUMO1/Ubc9 overexpression and restricted by SUMO1/Ubc9 depletion. We noted no effect on the expressions of SUMO1 and Ubc9 in B. melitensis 16M lipopolysaccharide-prestimulated mouse RAW264.7 macrophages. Additionally, intracellular survival of the 16MΔVirB2 mutant was lower than that of Brucella 16M (p < 0.05). VirB2 can affect expression levels of Ubc9, thereby increasing intracellular survival of Brucella in macrophages at the late stage of infection. Collectively, our results demonstrate that B. melitensis 16M may use the VirB IV secretion system of Brucella to interact with SUMO-related proteins during infection of host cells, which interferes with SUMO function and promotes pathogen survival in host cells.

Facile Fabrication of Hollow Li3PO4 Catalyst via Ostwald Ripening

Jihai Zhang,Dongyu Wang,Weihua Ma 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.1

Hollow inorganic nanostructures are important due to their applications in energy storage and conversion, catalysis, gas sensing, and biomedicine. Li3PO4 is used as an isomerization catalyst for propylene oxide to selectively give allyl alcohol. We used a facile template-free method to synthesize hollow Li3PO4 nanoparticles with size range of 500 nm to 1500 nm. The effect of concentration, agitation, ripening temperature and the ratio of starting reagents on the hollowing process is investigated. The most important factor to influence the hollowness was found to be the ratio of lithium ion to phosphate ion; as the ratio increases, the hollowness of the particles increases. When this ratio reached 3, the hollow nanostructures become dominant. As an isomerization catalyst for propylene oxide, 4-Li3PO4 exhibited the highest conversion and best selectivity of allyl alcohol. The hydroxide ion of the precursor is adsorbed on the surface of the Li3PO4 particles which results in different surface basicity.

Linking empowering leadership to innovative behavior in professional learning communities: the role of psychological empowerment and team psychological safety

Jinjie Zhu,Jihai Yao,Lili Zhang 서울대학교 교육연구소 2019 Asia Pacific Education Review Vol.20 No.4

This study investigates the mediating role of teachers’ psychological empowerment and the moderating role of team psychological safety in the relationship between empowering leadership and teachers’ innovative behavior in teaching and research groups (TR groups) as professional learning communities. In total, 507 teachers from 114 TR groups in China participated in this study. The multilevel model results show that empowering leadership improves teachers’ innovative behavior by increasing teachers’ psychological empowerment, which is not influenced by team psychological safety. A supplementary analysis shows that the relationship between team psychological safety and teachers’ innovative behavior is also mediated by psychological empowerment.

Computational fluid dynamics study on the anode feed solid polymer electrolyte water electrolysis

Shuguo Qu,Guanghui Chen,Jihai Duan,Weiwen Wang,Jianlong Li 한국화학공학회 2017 Korean Journal of Chemical Engineering Vol.34 No.6

A steady-state two-dimensional model for the anode feed solid polymer electrolyte water electrolysis (SPEWE) is proposed in this paper. Finite element procedure was employed to calculate the multicomponent transfer model coupled with fluid flow in flow channels and gas diffusion layers and electrochemical kinetics in catalyst reactive surface. The performance of the anode feed SPEWE predicted by this model was compared with the published experimental results and reasonable agreement was reached. The results show that oxygen mass fraction increases because of the water oxidation when water flows from the import to the export on the anode side. On the cathode side, hydrogen mass fraction varies little since hydrogen and water mix well. The flux of water across the electrolyte increased almost linearly with the increase of the applied current density. Since the ohmic overpotential loss increasing as the solid polymer electrolytes’ thickness increasing, the performance of the anode feed SPEWE with Nafion 112, 115, 117 decreases at the same applied current density.

Optimal Torque Management Strategy for a Parallel Hydraulic Hybrid Vehicle

Sun Hui,Jiang Jihai,Wang Xin 한국자동차공학회 2007 International journal of automotive technology Vol.8 No.6

The hydraulic hybrid vehicle (HHV) is an application of hydrostatic transmission technology to improve vehicle fuel economy and emissions. A relatively lower energy density of hydraulic accumulator and complicated coordinating operations between two power sources require a special energy management strategy to maximize the fuel saving potential. This paper presents a new type of configuration for parallel HHV to minimize the disadvantages of the hydraulic accumulator, as well as a methodology for developing an energy management strategy tailored specially for PHHV. Based on an analysis of the optimal energy distribution between two power sources over a representative urban driving cycle with a Dynamic Programming (DP) algorithm, a fuzzy-based optimal torque management strategy is designed and developed to control the torque distribution. Simulation results demonstrates that the optimal torque management strategy maximizes the advantages of this hybrid type of configuration, and the high power density characteristics of hydraulic technology effectively improve the robustness of the energy management strategy and fuel economy of the PHHV.

The Effect of H2O2/Fe2+ Catalytic Oxidation System on the Morphology, Structure and Properties of Flake-Like Poly(2,3-dimethylaniline)

Jun Yan,Li Ma,Mengyu Gan,Xiao Li,Zhitao Li,Jihai Tang,Ying Tu,Haifeng Hu 한국고분자학회 2014 Macromolecular Research Vol.22 No.8

In this work, flake-like poly(2,3-dimethylaniline) (P(2,3-DMA)) with enhanced thermal stability andanticorrosive ability was synthesized by in situ polymerization using H2O2/Fe2+ catalytic oxidation system, comparingwith traditional oxidant ammonium persulfate (APS) synthetic method. The structure and morphology of thesamples were characterized Fourier transform infrared (FTIR) spectra, X-ray diffraction (XRD) and field-emissionscanning electron microscope (FESEM). The experimental results demonstrated that using H2O2/Fe2+ catalytic oxidationsystem was more inclined to form the two-dimensional P(2,3-DMA) flakes. The enhancement in thermostabilityand corrosion resistance was attributed to the formation of phenazine-like structures in the polymer chains,which could serve as templates to form the flake-like morphology. In addition, using H2O2/Fe2+ catalytic oxidationsystem is more environmental friendly than the APS method that can avoid ammonium pollution on aquatic life aswell as waters.

Enhanced activity of MCM-48 based tin catalyst for synthesis of 3-methylbut-3-en-1-ol by adjusting the mesochannel environment

Zhaoyang Fei,Shenglan Ai,Zhe Zhou,Xian Chen,Jihai Tang,Mifen Cui,Xu Qiao 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.6

In the present work, tin incorporated MCM-48 catalysts were prepared by different strategies andapplied in the synthesis of MB-AC and MBOH. The performance of the catalysts is strongly affected bymesochannel environment and acid texture. The organic-graft method (Sn-G-MCM-48) can modify themesochannel environment and enhance the acid intensity and concentration (0.28 mmol/gcat),resulting in the improvement of the catalytic activity to the target reactions. The total yield of MB-AC andMBOH is as much as 68.4% over Sn-G-MCM-48 under mild conditions.

Porous nano-hydroxyapatites doped into substrate for thin film composite forward osmosis membrane to show high performance

Weiwen Wang,Yue Guo,Miyu Liu,Xiaokun Song,Jihai Duan 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.9

The incorporation of inorganic nanoparticles into thin film composite forward osmosis (TFC FO) membranes is an effective method to alleviate internal concentration polarization (ICP) and enhance the flux performance of the FO membrane. In this paper, synthetic hydrophilic rod-like porous nano-hydroxyapatites (PNHAs) were doped into polysulfone (PSf) casting solution to form support layer by phase inversion; further interfacial polymerization was carried out to prepare a high performance TFC FO membrane. The results showed that the incorporation of PNHAs not only improved the thickness, porosity, hydrophilicity, and connectivity of the support layer, but also enhanced the roughness of the active layer. The measured mass transfer parameters prove that these improvements were beneficial. Further FO experiments showed that when using deionized water as the feed solution and 1 mol/L NaCl as the draw solution, TFN 0.75 showed higher water flux than TFC FO membrane in both AL-FS (18.5 vs 7.16 L/m2 ·h) and AL-DS (33.26 vs 9.93 L/m2 ·h) modes. Reverse salt flux had not increased significantly. At the same time, TFN 0.75 (697 m vs 1,960 m) showed the smallest structural parameter. This study shows that PNHA is a suitable nanomaterial for mitigating the ICP effect of FO membranes.

A combined application of molecular docking technology and indirect ELISA for the serodiagnosis of bovine tuberculosis

Song, Shengnan,Zhang, Qian,Yang, Hang,Guo, Jia,Xu, Mingguo,Yang, Ningning,Yi, Jihai,Wang, Zhen,Chen, Chuangfu The Korean Society of Veterinary Science 2022 Journal of Veterinary Science Vol.23 No.3

Background: There is an urgent need to find reliable and rapid bovine tuberculosis (bTB) diagnostics in response to the rising prevalence of bTB worldwide. Toll-like receptor 2 (TLR2) recognizes components of bTB and initiates antigen-presenting cells to mediate humoral immunity. Evaluating the affinity of antigens with TLR2 can form the basis of a new method for the diagnosis of bTB based on humoral immunity. Objectives: To develop a reliable and rapid strategy to improve diagnostic tools for bTB. Methods: In this study, we expressed and purified the sixteen bTB-specific recombinant proteins in Escherichia coli. The two antigenic proteins, MPT70 and MPT83, which were most valuable for serological diagnosis of bTB were screened. Molecular docking technology was used to analyze the affinity of MPT70, MPT83, dominant epitope peptide of MPT70 (M1), and dominant epitope peptide MPT83 (M2) with TLR2, combined with the detection results of enzyme-linked immunosorbent assay to evaluate the molecular docking effect. Results: The results showed that interaction surface Cα-atom root mean square deviation of proteins (M1, M2, MPT70, MPT83)-TLR2 protein are less than 2.5 A, showing a high affinity. It is verified by clinical serum samples that MPT70, MPT83, MPT70-MPT83 showed good diagnostic potential for the detection of anti-bTB IgG and M1, M2 can replace the whole protein as the detection antigen. Conclusions: Molecular docking to evaluate the affinity of bTB protein and TLR2 combined with ELISA provides new insights for the diagnosis of bTB.

A combined application of molecular docking technology and indirect ELISA for the serodiagnosis of bovine tuberculosis

Song, Shengnan,Zhang, Qian,Yang, Hang,Guo, Jia,Xu, Mingguo,Yang, Ningning,Yi, Jihai,Wang, Zhen,Chen, Chuangfu The Korean Society of Veterinary Science 2022 Journal of Veterinary Science Vol. No.

Background: There is an urgent need to find reliable and rapid bovine tuberculosis (bTB) diagnostics in response to the rising prevalence of bTB worldwide. Toll-like receptor 2 (TLR2) recognizes components of bTB and initiates antigen-presenting cells to mediate humoral immunity. Evaluating the affinity of antigens with TLR2 can form the basis of a new method for the diagnosis of bTB based on humoral immunity. Objectives: To develop a reliable and rapid strategy to improve diagnostic tools for bTB. Methods: In this study, we expressed and purified the sixteen bTB-specific recombinant proteins in Escherichia coli. The two antigenic proteins, MPT70 and MPT83, which were most valuable for serological diagnosis of bTB were screened. Molecular docking technology was used to analyze the affinity of MPT70, MPT83, dominant epitope peptide of MPT70 (M1), and dominant epitope peptide MPT83 (M2) with TLR2, combined with the detection results of enzyme-linked immunosorbent assay to evaluate the molecular docking effect. Results: The results showed that interaction surface Cα-atom root mean square deviation of proteins (M1, M2, MPT70, MPT83)-TLR2 protein are less than 2.5 A, showing a high affinity. It is verified by clinical serum samples that MPT70, MPT83, MPT70-MPT83 showed good diagnostic potential for the detection of anti-bTB IgG and M1, M2 can replace the whole protein as the detection antigen. Conclusions: Molecular docking to evaluate the affinity of bTB protein and TLR2 combined with ELISA provides new insights for the diagnosis of bTB.