Search results

Filters

  • Journals
  • Authors
  • Keywords
  • Date
  • Type

Search results

Number of results: 3
items per page: 25 50 75
Sort by:
Download PDF Download RIS Download Bibtex

Abstract

In this study, medium-carbon steel was subjected to warm deformation experiments on a Gleeble 3500 thermosimulator machine at temperatures of 550°C and 650°C and strain rates of 0.001 s–1 to 1 s–1. The warm deformation behavior of martensite and the effects of strain rate on the microstructure of ultrafine grained medium-carbon steel were investigated. The precipitation behavior of Fe3C during deformation was analyzed and the results showed that recrystallization occurred at a low strain rate. The average ultrafine ferrite grains of 500 ± 58 nm were fabricated at 550°C and a strain rate of 0.001 s–1. In addition, the size of Fe3C particles in the ferrite grains did not show any apparent change, while that of the Fe3C particles at the grain boundaries was mainly affected by the deformation temperature. The size of Fe3C particles increased with the increasing deformation temperature, while the strain rate had no significant effect on Fe3C particles. Moreover, the grain size of recrystallized ferrite decreased with an increase in the strain rate. The effects of the strain rate on the grain size of recrystallized ferrite depended on the deformation temperature and the strain rate had a prominent effect on the grain size at 550°C deformation temperature. Finally, the deformation resistance apparently decreased at 550°C and strain rate of 1 s–1 due to the maximum adiabatic heating in the material.

Go to article

Authors and Affiliations

Q. Yuan
G. Xu
S. Liu
M. Liu
H. Hu
Download PDF Download RIS Download Bibtex

Abstract

Porcine circovirus type 2 (PCV2) is an economically important swine pathogen and, although small, it has the highest evolution rate among DNA viruses. Commercial PCV2 commercial vaccines are inactivated PCV2 isolates or a subunit vaccine based on the Cap protein of PCV2. Currently, PCV2 VLPs of individual subtype vaccines are available. Although the main prevalent genotype worldwide is PCV2b, the emerging subtype PCV2d subtype is also increasingly associated with PCV disease. The aim of the study was to evaluate the protective efficacy of VLP based on the PCV2b and 2d subtypes against the mixed challenge of two hypotype PCV2 in mice. Thirty-six female SPV Kunming mice were immunized twice with PCV2b and 2d VLPs, then challenged with PCV2b and PCV2d, to assess the immunogenicity and effectiveness of the VLPs. Vaccination of the mice with PCV2b and 2d VLPs elicited a robust antibody response specific for the PCV2. The virus load detected in the 2b and 2d spleen vaccine group was the lowest compared to other groups. Furthermore, there was no pathological damage in the HE stained sections of the 2b and 2d spleen vaccine, and no virus was detected in the immunohistochemical sections. Our data suggest that the mixed PCV2b and 2d VLP vaccine could protect mice from challenge with the mixed infection of PCV2b and PCV2d.
Go to article

Bibliography


Akahata W, Yang ZY, Andersen H, Sun S, Holdaway HA, Kong WP, Lewis MG, Higgs S, Rossmann MG, Rao S, Nabel GJ (2010) A virus-like particle vaccine for epidemic Chikungunya virus protects nonhuman primates against infection. Nat Med 16: 334-338.
Firth C, Charleston MA, Duffy S, Shapiro B, Holmes EC (2009) Insights into the evolutionary history of an emerging livestock pathogen: porcine circovirus 2. J Virol 83: 12813-12821.
Forstova J, Krauzewicz N, Wallace S, Street A J, Dilworth S M, Beard S, Griffin B E (1993) Cooperation of structural proteins during late events in the life cycle of polyomavirus. J Virol 67: 1405-1413.
Fraile L, Sibila M, Nofrarias M, Lopez-Jimenez R, Huerta E, Llorens A, Lopez-Soria S, Perez D, Segales J (2012) Effect of sow and piglet porcine circovirus type 2 (PCV2) vaccination on piglet mortality, viraemia, antibody titre and production parameters. Vet Microbiol 161: 229-234.
Ge X, Wang F, Guo X, Yang H (2012) Porcine circovirus type 2 and its associated diseases in China. Virus Res 164: 100-106.
Guo L, Fu Y, Wang Y, Lu Y, Wei Y, Tang Q, Fan P, Liu J, Zhang L, Zhang F, Huang L, Liu D, Li S, Wu H, Liu C (2012) A porcine circovirus type 2 (PCV2) mutant with 234 amino acids in capsid protein showed more virulence in vivo, compared with classical PCV2a/b strain. PLoS One 7: e41463.
Guo LJ, Lu YH, Wei YW, Huang LP, Liu CM (2010) Porcine circovirus type 2 (PCV2): genetic variation and newly emerging genotypes in China. Virol J 7: 273.
Hemann M, Beach NM, Meng XJ, Halbur PG, Opriessnig T (2012) Vaccination with inactivated or live-attenuated chimeric PCV1-2 results in decreased viremia in challenge-exposed pigs and may reduce transmission of PCV2. Vet Microbiol 158: 180-186.
Jiang W, Li M, He F, Zhou S, Zhu L (2017) Targeting the NLRP3 inflammasome to attenuate spinal cord injury in mice. J Neuroinflammation 14: 207.
Jourdan N, Godeke G J, Penaud M, Mottola G, Sorrentino A, Rottier P J, Bonatti S (2006) Assembly of HCV E1 and E2 glycoproteins into coronavirus VLPs. Arch Virol 151: 2085-2094.
Kixmoller M, Ritzmann M, Eddicks M, Saalmuller A, Elbers K, Fachinger V (2008) Reduction of PMWS-associated clinical signs and co-infections by vaccination against PCV2. Vaccine 26: 3443-3451.
Kwon T, Lee DU, Yoo SJ, Je SH, Shin JY, Lyoo YS (2017) Genotypic diversity of porcine circovirus type 2 (PCV2) and genotype shift to PCV2d in Korean pig population. Virus Res 228: 24-29.
Mohsen MO, Zha L, Cabral-Miranda G, Bachmann MF (2017) Major findings and recent advances in virus- -like particle (VLP)-based vac-cines. Semin Immunol 34: 123-132.
Nawagitgul P, Morozov I, Bolin SR, Harms PA, Sorden SD, Paul PS (2000) Open reading frame 2 of porcine circo- virus type 2 encodes a major capsid protein. J Gen Virol 81: 2281-2287.
Opriessnig T, Shen HG, Pal N, Ramamoorthy S, Huang YW, Lager KM, Beach NM, Halbur PG, Meng XJ (2011) A live-attenuated chimeric porcine circovirus type 2 (PCV2) vaccine is transmitted to contact pigs but is not upregulated by concurrent infection with porcine parvovirus (PPV) and porcine reproductive and respira- tory syndrome virus (PRRSV) and is efficacious in a PCV2b-PRRSV-PPV challenge model. Clin Vaccine Immunol 18: 1261-1268.
Palkova Z, Adamec T, Liebl D, Stokrova J, Forstova J (2000) Production of polyomavirus structural protein VP1 in yeast cells and its interac-tion with cell structures. FEBS Lett 478: 281-289.
Ramqvist T, Andreasson K, Dalianis T (2007) Vaccination, immune and gene therapy based on virus-like particles against viral infections and cancer. Expert Opin Biol Ther 7: 997-1007.
Salunke DM, Caspar DL, Garcea RL (1986) Self-assembly of purified polyomavirus capsid protein VP1. Cell 46: 895-904.
Segales J (2015) Best practice and future challenges for vaccination against porcine circovirus type 2. Expert Rev Vaccines 14: 473-487.
Segales J, Calsamiglia M, Olvera A, Sibila M, Badiella L, Domingo M (2005) Quantification of porcine circovirus type 2 (PCV2) DNA in serum and tonsillar, nasal, tracheo-bronchial, urinary and faecal swabs of pigs with and without postweaning multisystemic wasting syndrome (PMWS). Vet Microbiol 111: 223-229.
Segales J, Martinez-Guino L, Cortey M, Navarro N, Huerta E, Sibila M, Pujols J, Kekarainen T (2009) Retrospective study on swine Torque teno virus genogroups 1 and 2 infection from 1985 to 2005 in Spain. Vet Microbiol 134(3-4): 199-207.
Stewart M, Bhatia Y, Athmaran TN, Noad R, Gastaldi C, Dubois E, Russo P, Thiery R, Sailleau C, Breard E, Zientara S, Roy P (2010) Vali-dation of a novel approach for the rapid production of immunogenic virus-like particles for bluetongue virus. Vaccine 28: 3047-3054.
Szecsi J, Boson B, Johnsson P, Dupeyrot-Lacas P, Matrosovich M, Klenk HD, Klatzmann D, Volchkov V, Cosset FL (2006) Induction of neutralising antibodies by virus-like particles harbouring surface proteins from highly pathogenic H5N1 and H7N1 influenza viruses. Virol J 3: 70.
Wang F, Guo X, Ge X, Wang Z, Chen Y, Cha Z, Yang H (2009) Genetic variation analysis of Chinese strains of porcine circovirus type 2. Virus Res 145: 151-156.
Xiao CT, Halbur PG, Opriessnig T (2012) Complete genome sequence of a novel porcine circovirus type 2b variant present in cases of vac-cine failures in the United States. J Virol 86: 12469.
Xiao CT, Halbur PG, Opriessnig T (2015) Global molecular genetic analysis of porcine circovirus type 2 (PCV2) sequences confirms the presence of four main PCV2 genotypes and reveals a rapid increase of PCV2d. J Gen Virol 96: 1830-1841.
Xiao CT, Harmon KM, Halbur PG, Opriessnig T (2016) PCV2d-2 is the predominant type of PCV2 DNA in pig samples collected in the U.S. during 2014-2016. Vet Microbiol 197: 72-77.
Yang S, Yin S, Shang Y, Liu B, Yuan L, Zafar Khan MU, Liu X, Cai J (2018) Phylogenetic and genetic variation analyses of porcine circovirus type 2 isolated from China. Transbound Emerg Dis 65: e383-e392.
Yuan X, Lin H, Li B, He K, Fan H (2017) Efficacy and immunogenicity of recombinant swinepox virus expressing the truncated S protein of a novel isolate of porcine epidemic diarrhea virus. Arch Virol 162: 3779-3789.
Zhang Y, Wang Z, Zhan Y, Gong Q, Yu W, Deng Z, Wang A, Yang Y, Wang N (2016) Generation of E. coli-derived virus-like particles of porcine circovirus type 2 and their use in an indirect IgG enzyme-linked immunosorbent assay. Arch Virol 161: 1485-1491.
Go to article

Authors and Affiliations

X.M. Yuan
1
Q.C. Yuan
1
S.M. Feng
1
Z.B. Deng
1

  1. Laboratory of Animal Disease Prevention and Control and Animal model, Hunan Provincial Key Laboratory of Protein Engineering in Animal Vaccines, College of Veterinary Medicine, Hunan Agricultural University, No. 1 Nongda road, Furong District, Changsha, 410128, People’s Republic of China

This page uses 'cookies'. Learn more