Inhibition Effect of Hydrophobic Functional Organic Corrosion Inhibitor in Reinforced Concrete.

Using an admixed organic corrosion inhibitor is one of the most efficient strategies to enhance the corrosion resistance and durability of reinforced concrete. However, traditional admixed organic corrosion inhibitors only increase the corrosion resistance of the embedded reinforcing steel, and the optimization effect on the pore structure and the impermeability of concrete is very limited. In this study, in order to evaluate the corrosion-inhibition effect of a novel hydrophobic functional organic corrosion inhibitor, the adsorption behavior of a hydrophobic functional organic corrosion inhibitor and its related effect on the electrochemical behavior of the reinforcing steel was investigated. In addition, this paper further discusses the effect of a hydrophobic functional organic corrosion inhibitor on pore structure and hydrophobic properties, as well as the impermeability of concrete. The results indicated that the hydrophobic functional organic corrosion inhibitor was effectively adsorbed on the surface of the steel bar, and the higher adsorption content was relevant to the higher inhibitor dosage. On one hand, the hydrophobic functional organic corrosion inhibitor exhibited both a pore-blocking effect and a hydrophobic effect on concrete, leading to a refined pore structure and reduced capillary water absorption amount; on the other hand, the hydrophobic functional organic corrosion inhibitor exhibited an excellent corrosion-inhibition effect on the reinforcement embedded in the concrete, presenting an inhibition efficiency higher than 90% with a concentration of 4 wt.%.

The aflatoxin-detoxifizyme specific expression in the parotid gland of transgenic pigs.

Producing aflatoxin-detoxifizyme (ADTZ) in pigs to control the AFT contamination of pig feed is a new research strategy by transgenic technology. In this study, transgenic pigs specifically expressing ADTZ gene in the parotid gland were successfully produced by somatic cell nuclear transfer technology. The ADTZ activity in saliva of 6 transgenic pigs was found to be 7.11 ± 2.63 U/mL. The feeding trial with aflatoxin (AFT) results showed that there were significant difference about the serum biochemical index such as total protein (TP), albumin (ALB), globulin (GLB) contents and alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activity and AFT residues in serum and liver between the pigs in the test treatment (transgenic pigs) producing ADTZ and those in the positive control (P < 0.05). In order to investigate the inheritance of the transgene, 11 G1 transgenic pigs were successfully obtained. The ADTZ activity in saliva of 11 G1 transgenic pigs was found to be 5.82 ± 1.53 U/mL. The feeding trial with AFT results showed that the serum biochemical index containing TP, ALB and GLB contents and ALT and AST activity and AFB1 residues in serum and liver of the pigs in the test treatment (transgenic pigs) producing ADTZ were significantly different than those in the positive control (P < 0.05). The above results demonstrated that ADTZ produced in transgenic pigs could improve the effect of the AFT contamination of feed on pigs.

Improvement of anti-nutritional effect resulting from ß-glucanase specific expression in the parotid gland of transgenic pigs.

ß-Glucan is the predominant anti-nutritional factors in monogastric animal feed. Although ß-glucanase supplementation in diet can help to eliminate the adverse effects, enzyme stability is substantially modified during the feed manufacturing process. To determine whether the expression of endogenous ß-glucanase gene (GLU) in vivo can improve digestibility of dietary ß-glucan and absorption of nutrients, we successfully produced transgenic pigs via nuclear transfer which express the GLU from Paenibacillus polymyxa CP7 in the parotid gland. In three live transgenic founders, ß-glucanase activities in the saliva were 3.2, 0.07 and 0.03 U/mL, respectively, and interestingly the enzyme activities increased in the pigs from 178 days old to 789 days old. From the feed the amount of gross energy, crude protein and crude fat absorbed by the transgenic pigs was significantly higher than the non-transgenic pigs. Meanwhile the moisture content of the feces was significantly reduced in transgenic pigs compared with the non-transgenic pigs. Furthermore, in all positive G1 pigs, ß-glucanase activity was detectable and the highest enzyme activity reached 3.5 U/mL in saliva. Also, crude protein digestion was significantly higher in G1 transgenic pigs than in control pigs. Taken together, our data showed that the transgenic ß-glucanase exerted its biological catalytic function in vivo in the saliva, and the improved performance of the transgenic pigs could be accurately passed on to the offspring, indicating a promising alternative approach to improving nutrient availability was established to improve utilization of livestock feed through transgenic animals.

The aflatoxin-detoxifizyme specific expression in mouse parotid gland.

The aflatoxin-detoxifizyme (ADTZ) gene derived from Armillariella tabescens was cloned into parotid gland-specific expression vector (pPSPBGPneo) to construct the parotid gland-specific vector expressing ADTZ (pPSPBGPneo-ADTZ). Transgenic mice were generated by microinjection and identified by using PCR and Southern blotting analysis. PCR and Southern blotting analysis showed that total six transgenic mice carried the ADTZ gene were generated. RT-PCR analysis indicated that the expression of ADTZ mRNA could be detected only in parotid glands of the transgenic mice. The ADTZ activity in the saliva was found to be 3.72 ± 1.64 U/mL. After feeding a diet containing aflatoxin B1 (AFB1) for 14 days, the effect of ADTZ on serum biochemical indexes and AFB1 residues in serum and liver of mice were evaluated. The results showed that total protein and globulin contents in the test treatment (transgenic mice) produced ADTZ were significantly higher than that of the positive control, while alanine aminotransferase and aspartate aminotransferase activity in serum of the test treatment (transgenic mice) were remarkably lower compared to that of the positive control (P < 0.05). Moreover, AFB1 residues in serum and liver of the test treatment (transgenic mice) were significantly lower compared with that of the positive control (P < 0.05). These results in the study confirmed that ADTZ produced in transgenic mice could reduce, even eliminate the negative effects of AFB1 on mice.

Construction and characterization of a recombinant canine adenovirus expressing GP5 and M proteins of porcine reproductive and respiratory syndrome virus.

The causative agent of porcine reproductive and respiratory syndrome (PRRS) is PRRS virus (PRRSV), which belongs to the family Arteriviridae. GP5/M protein complex of PRRSV binds to sialoadhesion expressed on the cells to infect the cells. In this study, we developed a canine adenovirus type 2 (CAV-2) recombinant, termed rCAV2-GP5/M, expressing GP5 and M proteins. To evaluate the immunogenicity of the recombinant virus, mice were inoculated subcutaneously with rCAV2-GP5/M, and specific antibodies against PRRSV in the sera were measured by enzyme-linked immunosorbent assay and the viral neutralization test. Two weeks post-immunization (w.p.i.), anti-PRRSV antibodies were detected in the sera, slightly increased by booster immunization at four w.p.i., and then gradually decreased. The viral neutralizing test showed that neutralizing antibodies were present in the sera collected at two w.p.i., increased by booster immunization, and reached the maximum titer at six w.p.i. Lymphocyte proliferation responding to PRRSV antigens was also observed from two w.p.i. Although further studies are needed to evaluate the usefulness of the recombinant virus to protect pigs from PPRSV, we succeeded in developing a candidate vaccine against PPRSV infection by using CAV-2 vector.