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Thermoplastic polyurethane (TPU) is easy to burn and limits its safe use. In order to improve its flame retardant properties, an appropriate amount of modified magnesium hydroxide (Mg(OH)2) and expanded graphite (EG) were doped in the TPU matrix, and the flame retardant properties of the composites were investigated. The results show that compared with the unmodified TPU material, the TPU composite material doped with 20% EG and modified Mg(OH)2 has better comprehensive performance. The LOI value of TPU/Mg(OH)2/EG20% composite is 30.6%, the heat release rate was 115 kW/m², and the total smoke is 43 m². The thermal stability of TPU/Mg(OH)2/EG20% composites is improved, and the modified TPU composites has better flame retardant effect and thermal stability. [ABSTRACT FROM AUTHOR]

Abstract Background Infection with the protozoan Toxoplasma gondii causes serious public health problems and is of great economic importance worldwide. Protection from acute toxoplasmosis is known to be mediated by CD8+ T cells, but the T. gondii antigens and host genes required for eliciting protective immunity have been poorly defined. The T. gondii dense granule protein 6 (GRA6), recently proved to be highly immunogenic and produces fully immune protection in T. gondii infected BALB/c mice with an H-2Ld gene. The CD8+ T cell response of H-2Ld mice infected by the T. gondii strain seemed to target entirely to a single GRA6 peptide HF10-H-2Ld complex. Results To determine whether a GRA6-based DNA vaccine can elicit protective immune responses to T. gondii in BALB/c mice, we constructed a eukaryotic expression vector pcDNA3.1-HisGRA6 and tested its immunogenicity in a mouse model. BALB/c mice were vaccinated intramuscularly with three doses of GRA6 DNA and then challenged with a lethal dose of T. gondii RH strain tachyzoites. All immunized mice developed high levels of serum anti-GRA6 IgG antibodies, and in vitro splenocyte proliferation was strongly enhanced in mice adjuvanted with levamisole (LMS). Immunization with pcDNA3.1-HisGRA6 with LMS resulted in 53.3% survival of challenged BALB/c mice as compared to 40% survival of BALB/c without LMS. Additionally, immunized Kunming mice without an allele of H-2Ld failed to survive. Conclusions Our result supports the concept that the acquired immune response is MHC restricted. This study has a major implication for vaccine designs using a single antigen in a population with diverse MHC class I alleles.

Pseudanoplocephala crawfordiis one of the important zoonotic cestodes causing economic significance and public health concern. In the present study, the phylogenetic position ofP. crawfordiisolated from pigs was re-inferred using molecular markers of internal transcribed spacer ribosomal DNA (ITS rDNA) and partial NADH dehydrogenase subunit 1 (pnad1) mitochondrial DNA. The lengths of ITS1, ITS2 rDNA and pnad1 were 757 bp, 628 bp and 458 bp, respectively. Sequence differences in the ITS1, ITS2 rDNA and pnad1 betweenP. crawfordiandHymenolepisspecies were smaller than that between cestodes within genusHymenolepis. Phylogenetic analyses based on three gene fragments showed thatP. crawfordiwas grouped into cluster ofHymenolepisspecies. These results suggested thatP. crawfordiwould be one member of genusHymenolepisbut not in a new genusPseudanoplocephala. [ABSTRACT FROM PUBLISHER]

According to the fishery resources investigation data in the east of the Nanji Islands during autumn in 2017 and spring in 2018, the inter-specific relationships and ecological relationships between major nekton were analyzed via the index of relative importance, niche breadth, cluster analysis, niche overlap, χ 2 -test, variance ratio test, association coefficient, percentage of co-occurrence, and point correlation coefficients. The results showed that there were 30 major nekton species in this area. The dominant species were Harpadon nehereus, Portunus trituberculatus, and Oratosquilla oratoria. The niche width of these dominant species was relatively wide. Based on the cluster analysis of niche breadth, the 30 major nekton species could be divided into three categories, wide niche breadth species, moderate niche breath species, and narrow niche breath species. The distribution range of niche overlap value was [0, 0.98], indicating that there were differences in the similarity of species to resource utilization and that the niche was differentiated and accompanied by inter-specific competition. The values of VR and W showed that there was a significant positive correlation among the major nekton species. The χ 2 -test results indicated significantly interspecific association for 76 species pair (χ 2 ≥3.841), which was related to community stability and species coexistence. Results of association coefficient, percentage of co-occurrence and point correlation coefficients test suggested that the interspecific association was strong and tended to be positive.