Protective Immune Response of Bacterially-Derived Recombinant FaeG in Piglets

Yahong, Huang,Liang, Wanqi,Pan, Aihu,Zhou, Zhiai,Wang, Qiang,Huang, Cheng,Chen, Jianxiu,Zhang, Dabing The Microbiological Society of Korea 2006 The journal of microbiology Vol.44 No.5

FaeG is the key factor in the infection process of K88ad enterotoxigenic Escherichia coli (ETEC) fimbrial adhesin. In an attempt to determine the possibility of expressing recombinant FaeG with immunogenicity for a new safe and high-production vaccine in E. coli, we constructed the recombinant strain, BL21 (DE3+K88), which harbors an expression vector with a DNA fragment of faeG, without a signal peptide. Results of 15% SDS-polyacrylamide slab gel analysis showed that FaeG can be stably over-expressed in BL21 (DE3+K88) as inclusion bodies without FaeE. Immunoglobulin G (IgG) and M (IgM) responses in pregnant pigs, with boost injections of the purified recombinant FaeG, were detected 4 weeks later in the sera and colostrum. An in vitro villius-adhesion assay verified that the elicited antibodies in the sera of vaccinated pigs were capable of preventing the adhesion of K88ad ETEC to porcine intestinal receptors. The protective effect on the mortality rates of suckling piglets born to vaccinated mothers was also observed one week after oral challenge with the virulent ETEC strain, $C_{83907}$ (K88ad, $CT^+,\;ST^+$). The results of this study proved that the adhesin of proteinaceous bacterial fimbriae or pili could be overexpressed in engineered E. coli strains, with protective immune responses to the pathogen.

Finite Element Analysis on the Mechanical Properties of Self-lubricating Fabric Liners Based on Periodic Boundary Conditions

Yahong Xue,Jigang Chen,Xin Shi,Jichuan Yao,Junting Luo 한국섬유공학회 2018 Fibers and polymers Vol.19 No.3

A new parameterized finite element model was established for self-lubricating fabric liners in different weaving patterns. This model precisely simulated the spatial configuration of woven yarns with consideration of the cross-section deformation as well as the anisotropic material characteristics of yarns by converting the principal material direction along the yarn-path. Moreover, a set of simple and universal periodic boundary equations was proposed to solve the problem of the overabundance restriction in the boundary surfaces. To verify the validation of the finite element method proposed in this paper, an experimental prediction on elastic constants of self-lubricating fabric liners was carried out. The results indicate that the finite element model can successfully predict the macro mechanical properties of self-lubricating fabric liners with periodical structures. Based on the finite element model, the distributions of stress and strain, as well as the effects of weaving type and weaving density on the elastic modulus of fabric liners were investigated in details.

Superwetting TiO2-decorated single-walled carbon nanotube composite membrane for highly efficient oil-in-water emulsion separation

Yahong Sun,Ruiguang Zhao,Quanyong Wang,Yuanyuan Zheng,Gongrang Li,Dejun Sun,Tao Wu,Yujiang Li 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.11

With the advantages of one-dimensional hollow structure, high porosity and prominent mechanical strength, single-walled carbon nanotubes (SWCNTs) have been extensively utilized to improve conventional filtration membranes for oil/water separation. Their intrinsic hydrophobicity, however, adversely affects the anti-fouling performance of the SWCNT membrane. Herein, a super-hydrophilic and underwater super-oleophobic hierarchical modified membrane with enhanced permeability and anti-fouling property was fabricated using the vacuum-assisted filtration technique by synergistically assembling SWCNTs and titanium dioxide (TiO2) nanoparticles on a cellulose acetate membrane. Highly dispersed SWCNTs were obtained by carboxylating treatment of agglomerate SWCNTs. The controlled stacking of SWCNTs fibers and a controllable amount of TiO2 rendered a modified membrane with high porosity and hierarchical structure, leading to an ultrahigh water flux up to 4,777.07 L·m2·h1, and excellent separation performance with efficiency greater than 99.47%. Most importantly, the membrane exhibited excellent anti-fouling ability during ten cycles with the aid of the super-wetting property of TiO2 nanoparticles. The results indicated that coating TiO2 nanoparticles on SWCNTs modified the surface topography of the obtained SWCNT/TiO2 membrane, which improved hydrophilicity, permeability and anti-fouling property, manifesting attractive potential applications in oil/water separation.

Protective Immune Response of Bacterially-Derived Recombinant FaeG in Piglets

Huang Yahong,Wanqi Liang,Aihu Pan,Zhiai Zhou,Qiang Wang,Cheng Huang,Jianxiu Chen,Dabing Zhang 한국미생물학회 2006 The journal of microbiology Vol.44 No.5

FaeG is the key factor in the infection process of K88ad enterotoxigenic Escherichia coli(ETEC) fimbrial adhesin. In an attempt to determine the possibility of expressing recombinant FaeG with immunogenicity for a new safe and high-production vaccine in E. coli, we constructed the recombinant strain, BL21 (DE3+K88), which harbors an expression vector with a DNA fragment of faeG, without a signal peptide. Results of 15% SDS-polyacrylamide slab gel analysis showed that FaeG can be stably over-expressed in BL21 (DE3+K88) as inclusion bodies without FaeE. Immunoglobulin G (IgG) and M (IgM) responses in pregnant pigs, with boost injections of the purified recombinant FaeG, were detected 4 weeks later in the sera and colostrum. An in vitro villius-adhesion assay verified that the elicited antibodies in the sera of vaccinated pigs were capable of preventing the adhesion of K88ad ETEC to porcine intestinal receptors. The protective effect on the mortality rates of suckling piglets born to vaccinated mothers was also observed one week after oral challenge with the virulent ETEC strain, C83907 (K88ad, CT+, ST+). The results of this study proved that the adhesin of proteinaceous bacterial fimbriae or pili could be overexpressed in engineered E. coli strains, with protective immune responses to the pathogen.

The Synoptic and Climate Feather of Dense Fog in Shenshan Highway, Its Impact to Traffic, and Preventing Strategy

Hou Yahong 한국기상학회 2015 한국기상학회 학술대회 논문집 Vol.2015 No.10

Mechanism of cell cycle arrest by (8E,13Z,20Z)-strobilinin/(7E,13Z,20Z)-felixinin from a marine sponge Psammocinia sp.

Jiang, Yahong,Ahn, Eun-Young,Ryu, Seung-Hee,Kim, Dong-Kyoo,Park, Jang-Su,Kang, Shin Won,You, Song,Lee, Burm-Jong,Jung, Jee H National Hellenic Research Foundation 2005 Oncology reports Vol.14 No.4

<P>Furanosesterterpenes, isolated from a marine sponge Psammocinia sp. have been reported to display significant cytotoxicity to some cancer cell lines. In this study, EZZ, an inseparable 1:1 mixture of (8E,3Z,20Z)-strobilinin and (7E,3Z,20Z)-felixinin, showed significant antiproliferative effect on human cervix carcinoma cell line (HeLa). Cell cycle analysis revealed that EZZ could arrest HeLa cells in S phase with a concomitant decrease in the cell population of G1 phase. By using simian virus (SV40) DNA in vitro replication system, we found that EZZ could inhibit DNA replication, which suggests that EZZ-induced S phase arrest might be the direct result of blocked DNA synthesis. Furthermore, low concentration of EZZ was found to be capable of significantly inhibiting the DNA cleavage by topoisomerase I (topo I) and reducing the polymerase alpha-primase (pol alpha-primase) activity, while the ssDNA binding activity of replication protein A (RPA) was less affected. Taken together, these results suggest that EZZ-induced cell cycle arrest in S phase correlate with the inhibition of DNA replication, and topo I and pol alpha-primase might be the two main target molecules.</P>

Cytophaga hutchinsonii chu_2177, encoding the O-antigen ligase, is essential for cellulose degradation

Tan Yahong,Song Wenxia,Gao Lijuan,Zhang Weican,Lu Xuemei 한국미생물학회 2022 The journal of microbiology Vol.60 No.4

Cytophaga hutchinsonii can efficiently degrade crystalline cellulose, in which the cell surface cellulases secreted by the type IX secretion system (T9SS) play important roles, but the degradation mechanism remains unclear, and the anchor mechanism of cellulases on the outer membrane in C. hutchinsonii has not been studied. Here, chu_2177 was identified by transposon mutagenesis and was proved to be indispensable for cellulose utilization in C. hutchinsonii. Disruption of chu_2177 resulted in O-antigen deficiency and chu_ 177 could confer O-antigen ligase activity upon an Escherichia coli waal mutant, indicating that chu_2177 encoded the Ontigen ligase. Moreover, deletion of chu_2177 caused defects in cellulose utilization, cell motility, biofilm formation, and stress resistance. Further study showed that the endoglucanase activity was markedly decreased in the outer membrane but was increased in the culture fluid without chu_2177. Western blot proved that endoglucanase CHU_1336 was not located on the outer membrane but was released in the culture fluid of the Δ2177 mutant. Further proteomics analysis showed that many cargo proteins of T9SS were missing in the outer membrane of the Δ2177 mutant. Our study revealed that the deletion of chu_2177 affected the localization of many T9SS cargo proteins including cellulases on the outer membrane of C. hutchinsonii.

Glypican 2 regulates cell proliferation and metastasis in thyroid cancer cells

Tao Zhang,Yahong Liu,Xuan Ren,Zhuanping Wang,Hongjuan Wang 대한독성 유전단백체 학회 2020 Molecular & cellular toxicology Vol.16 No.2

Background Glypicans play a role in the growth and metastasis of several human cancers. However, little is known about its function in thyroid cancer. Therefore, this study aimed to investigate the specific functions of glypican 2 (GPC2) in thyroid cancer cells. Objective The expression of six glypican family members (GPC1 to GPC6) was detected in different thyroid cancer cell lines. The abnormal expression of GPC2 was confirmed by immunohistochemistry in or around thyroid tumor tissues. It was overexpressed and silenced in highly (TPC1 and FTC-133) and poorly (ARO) differentiated thyroid cancer cell lines, respectively. Subsequently, its role in cell proliferation, apoptosis, migration, and invasion was investigated. Results We observed that almost all glypican family members were highly expressed in thyroid cancer cells, and GPC2 expression was higher in poorly differentiated thyroid cancer cell lines than highly differentiated cell lines. The knockdown of GPC2 inhibited cell proliferation, invasion, and migration and promoted apoptosis in the ARO cells, whereas GPC2 overexpression promoted cell proliferation, invasion, and migration and inhibited apoptosis in the TPC1 and FTC-133 cells. Conclusions GPC2 is highly expressed in thyroid cancer tissues and regulates cell viability, apoptosis, migration, and invasion.

Integrated Simulation and Experimental Test of the Residual Stress Field for Large-sized Straight Welded Pipe Processed with JCOE Technology

Junting Luo,Yahong Xue,Ke Chen,Yanpeng Shang,Chunxiang Zhang 한국강구조학회 2017 International Journal of Steel Structures Vol.17 No.1

Continuous integrated simulation of JCO forming, reducing gap, welding, and mechanical expanding processes of large-sized straight welded pipe is conducted using Marc software. Taking expanding ratio as variable, the residual stress distribution of weld bead and the influence rule of the expanding ratio are investigated before and after expansion. In thickness direction, in the bonding zone of pre-welding and outside weld, as well as at the bottom of the inside weld, the residual stress is large before expanding. The residual stress in the outside weld is large after expanding. The peak value of residual stress is decreased by about 61 to 78%. The expanding ratio is higher, the peak clipping effect becomes more evident, and residual stress becomes more uniform. The simulation results agrees with the test results, thus confirm that integrated simulation can achieve the visualization of residual stress evolution in the production process of large-sized straight welded pipe.

CITIZEN PARTICIPATION IN LOCAL BUDGETING: MECHANISMS, POLITICAL SUPPORT, AND CITY MANAGER’S MODERATING ROLE

YUGUO LIAO,YAHONG ZHANG 한국행정학회 2012 International Review of Public Administration Vol.17 No.2

Previous studies have identified several predictors of citizen participation in local budgeting, including environmental factors,engagement mechanisms, and the role of public administrators. However,none has studied the interaction effect among these factors. This study seeks to fill this research gap. It argues that the utilization of interactive engagement mechanisms and political environment will have direct impact on the level of citizen participation in budgeting. These relationships are then moderated by municipal managers’ intention to incorporate citizens. Data from a survey of New Jersey municipal administrators were used to test the hypotheses, with controlling for demographic variables in seemingly unrelated regression (SUR) models.