Investigation on the Thermo-Oxidative Degradation of Polyethylene, Poly(vinyl chloride), and Polystyrene Using NiPIm1.5 and NiPIm2 Nanocomposites.

In this work, we report the synthesis of two nanoscale composites of nickel, NiPIm1.5 and NiPIm2 (NiPIm1.5 = [Ni(C3H4N2)(H2O)5](HPO4)(H2O)·0.3(C3H4N2) and NiPIm2 = [Ni(C3H4N2)(H2O)5](HPO4)(H2O)·0.4(C3H4N2)·H2O), characterization by various instrumental methods and the investigation of the thermo-oxidative degradation of polyethylene (PE), poly(vinyl chloride) (PVC), and polystyrene (PS) in the presence of both nanocomposites. All of these polymers are subjected to thermal treatment with and without composites at 353 K for 120 min. The rate of degradation is maximum with NiPIm2 for all three polymers, PE-13.1522%, PS-13.6152%, and PVC-8.04%, whereas with NiPIm1.5, PE-7.3128%, PS-11.9837%, and PVC-4.9106%. The percentage of degradation in the presence of composites is much greater than the percentage of degradation without composites. The specific heat capacities of NiPIm1.5 and NiPIm2 are -148.42 and -348.64 J kg-1 K-1, respectively. The degradation process takes place by free radical mechanism. Thermogravimetric and differential thermal analyses revealed that the temperatures corresponding to the formation of composite materials with NiPIm2 are 338.76, 331.78, and 354.30 K for PE, PVC, and PS, respectively. The temperatures of formation of the above composites are found to be less than that of NiPIm1.5. The degraded residues of polymers indicate that ester is formed in each case along with other byproducts containing imidazole. Infrared studies revealed the thermal oxidation of hydroperoxides and the formation of ketone.

Overexpression of T-bet, GATA-3 and TGF-ß Induces IFN-γ, IL-4/13A, and IL-17A Expression in Atlantic Salmon.

The overexpression of GATA-3, T-bet and TGF-ß may theoretically induce IL-4/A, IFN-γ and IL-17A expression, respectively. Whether this also applies to fish is not yet known. The plasmid vectors encoding reporter gene (RFP)-tagged T-bet, GATA-3 and TGF-ß were used as overexpression tools, transfected into cells or injected intramuscularly to monitor the expression of IFN-γ, IL-4/13A and IL-17A. In addition, the fish were either experimentally challenged with Vibrio anguillarum (VA group) or Piscirickettsia salmonis (PS group). The reporter gene (RFP) inserted upstream of the GATA-3, T-bet and TGF-ß genes, was observed in muscle cell nuclei and in inflammatory cells after intramuscular (i.m.) injection. PS group: following the injection of GATA-3 and T-bet-encoding plasmids, the expression of GATA-3 and T-bet was high at the injection site. The spleen expression of IFN-γ, following the injection of a T-bet-encoding plasmid, was significantly higher on day 2. VA group: The T-bet and GATA-3-overexpressing fish expressed high T-bet and GATA-3 mRNA levels in the muscles and on day 4 post-challenge. The expression of TGF-ß in the muscles of fish injected with TGF-ß-encoding plasmids was significantly higher on days 7 (8 days pre-challenge) and 19 (4 days after challenge). The protective effects of the overexpression of T-bet, GATA-3 and TGF-ß on both bacterial infections were negligible.

Transcription Factor T-Bet in Atlantic Salmon: Characterization and Gene Expression in Mucosal Tissues during Aeromonas Salmonicida Infection.

The T-box transcription factor T-bet is expressed in a number of hematopoietic cell types in mammals and plays an essential role in the lineage determination of Th1 T-helper cells and is considered as an essential feature for both innate and adaptive immune responses in higher vertebrates. In the present study, we have identified and characterized the full-length Atlantic salmon T-bet cDNA (3502 bp). The putative primary structure of the polypeptide deduced from the cDNA sequence contained 612 aa, which possessed a T-box DNA binding domain. Phylogenetic study and gene synteny revealed it is as a homolog to mammalian T-bet. Quantitative PCR analysis of different tissues in healthy fish showed that salmon T-bet gene was highly expressed in spleen, followed by head kidney, and was expressed in intestine, skin, and liver at lower levels. Moreover, the time-dependent expression profile of T-bet, interferon gamma (IFNγ), interleukin-22 (IL-22), and natural killer enhancement factor in mucosal tissues during water-borne infection with live Aeromonas salmonicida, indicated the involvement of T-bet in mucosal immune response in Atlantic salmon.

Bath immunostimulation of rainbow trout (Oncorhynchus mykiss) fry induces enhancement of inflammatory cytokine transcripts, while repeated bath induce no changes.

The application of immunostimulants may be a cost-effective practice in production of delicate and fragile fish fry since it may confer disease resistance. Bath administration to fish fry is considered an ideal delivery route for mass manipulation since there is no need for individual handling. In the current study, rainbow trout fry were bathed with three different immunostimulants: Plasmid DNA, lactoferrin and beta-glucan at two different doses (0.1 microM and 1.0 microM) for 45 min, four times with an interval of 1 week. Ten fish per treatment group were sampled, and RNA of pooled tissues consisting of eye, tongue, skin, gill, thymus, spleen, head kidney, liver, small and large intestine were isolated from the fish obtained at first, second and fourth bathing (24 and 72 h post-bathing). Before cDNA transcription, two parallel samples were pooled giving a total of 5 parallels in each treatment group. Results showed that plasmid DNA and lactoferrin as well as beta-glucan treated fish possessed higher gene expression with regard to the pro-inflammatory cytokines IL-1beta, TNF-alpha, IL-6 and the anti-inflammatory cytokines IL-10 and TGF-beta after the first bathing, especially 24 h post-bathing in the high-dose groups. This indicates that bath delivery of immunostimulants can induce pro-inflammatory responses. No significant changes of the pro-inflammatory cytokine IL-17A transcripts, compared to the respective controls, were observed. Gene expression levels in the immunostimulated fish after the fourth bathing did not show significant differences compared to controls.