Self-assembled nanoparticle with E protein domain III of DTMUV based on ferritin as carrier can induce a more comprehensive immune response and against DTMUV challenge in duck.

Duck Tembusu virus (DTMUV) causes severe reduction in egg production and neurological symptoms in ducklings. Vaccination is the primary measure used to prevent DTMUV infections. In this study, self-assembled nanoparticles with the E protein domain III of DTMUV, using ferritin as a carrier (EDⅢ-RFNp), were prepared using a prokaryotic expression system. Ducks were intramuscularly vaccinated with EDⅢ-RFNp, EDⅢ protein, an inactivated vaccine HB strain (InV-HB), and PBS. At 0, 4, and 6 weeks post-primary vaccination, the EDIII protein-specific antibody titre, IL-4, and IFN-γ concentrations in serum were determined by ELISA, and neutralising antibodies titres in sera were determined by virus neutralising assay. Peripheral blood lymphocytes proliferation was determined by CCK-8 kit. Following challenge with the virulent DTMUV strain, the clinical signals and survival rate of the vaccinated ducks were recorded, and DTMUV RNA levels in the blood and tissues of the surviving ducks were determined by real-time quantitative RT-PCR. The near-spherical EDⅢ-RFNp nanoparticles with 13.29 ± 1.43 nm diameter were observed by transmission electron microscope. At 4 and 6 weeks post-primary vaccination, special and Virus neutralisation (VN) antibodies, lymphocyte proliferation (stimulator index, SI), and concentrations of IL-4 and IFN-γ in the EDⅢ-RFNp group were significantly higher than in the EDⅢ and PBS groups. In the DTMUV virulent strain challenge test, the EDⅢ-RFNp-vaccinated ducks showed milder clinical signs and higher survival rates than EDⅢ- and PBS-vaccinated ducks. The DTMUV RNA levels in the blood and tissues of EDⅢ-RFNp-vaccinated ducks were significantly lower than those in EDⅢ- and PBS-vaccinated ducks. Additionally, the EDⅢ protein-special and VN antibodies, SI value, and concentration of IL-4 and IFN-γ in the InV-HB group was significantly higher than that of the PBS group at 4 and 6 weeks post-primary vaccination. InV-HB provided more efficient protection than PBS based on a higher survival rate, milder signals, and lower levels of the DTMUV virus in the blood and tissues. These results indicated that EDⅢ-RFNp effectively protected ducks against DTMUV challenge and could be a vaccine candidate to prevent DTMUV infection.

Two-dimensional topological insulators exfoliated from Na3Bi-like Dirac semimetals.

Topological insulation is widely predicted in two-dimensional (2D) materials realized by epitaxial growth or van der Waals (vdW) exfoliation. Such 2D topological insulators (TI's) host many interesting physical properties such as the quantum spin Hall effect and superconductivity. Here, we extend the search of 2D TI's into the exfoliatable non-vdW 2D crystals. We find that three-dimensional Dirac semimetals A3Bi (A = Na, K, Rb) (P3[combining macron]c1) can be exfoliated into 2D materials with exfoliation energies of 0.479-0.990 J m-2. Our careful examination of the topological invariants of exfoliated A3Bi monolayers/multilayers by using two well-established approaches reveals that bilayer and tetralayer Na3Bi are 2D TI's. It is found that the band gap of 2D TI's can be significantly increased by external strain. We further find that the predicted 2D TI's possess interesting hidden Rashba-like spin textures. Our results suggest a new arena to search for two-dimensional topological insulators and spintronic materials.

[Chemical constituents of rhizomes of Smilax ferox].

OBJECTIVE: To study the chemical constituents of the rhizomes of Smilax ferox which was widely used in the folk. METHOD: The constituents of the rhizomes of S. ferox were isolated and purified by repeated silica gel column, MCI column, Sephadex LH-20 column and RP C18 column chromatography, and their structures were elueidated on the basis of spectral analysis. RESULT: Six compounds were identified as dihydrokaempferol (1), kaempferol (2), astilbin (3), engeletin (4), resveratrol (5), beta-sitosterol (6), respectively. CONCLUSION: All compounds were obtained from this plant for the first time.

Influence of an aqueous extract of Ligustrum lucidum and an ethanol extract of Schisandra chinensis on parameters of antioxidative metabolism and spleen lymphocyte proliferation of broilers.

The study was conducted to evaluate the effects of dietary supplementation with different levels of two extracts, an aqueous extract of Ligustrum lucidum (AELL), and an ethanol extract of Schisandra chinensis (EESC) on growth performance, parameters of antioxidative status and spleen lymphocyte proliferation of broilers, respectively. The results showed that neither AELL nor EESC had significant effects on growth performance of broilers. However, malondialdehyde concentration in heart and liver of the broilers were significantly decreased by feeding AELL or EESC. Superoxide dismutase activity in heart, liver, and kidney of broilers were improved by feeding different dosages of AELL or EESC. In contrast, glutathione reductase activity in serum, heart and kidney of broilers was not affected by experimental treatment. In addition, spleen lymphocyte proliferation of broilers was significantly enhanced by feeding different dosages of AELL or EESC. In conclusion, the results suggested that either AELL or EESC may improve antioxidant status and immune function of broilers.