The beneficial effects of Sr-and Mg-doped hydroxyapatite (HAp) on osteoblast proliferation and bone regeneration have been investigated in the past, and the antibacterial ability of Zn ions is well known. However, HAp coatings doped with these three elements via thermal spraying have not yet been investigated. In this study, HAp powder was synthesized at different pH values (4, 6, 8, and 10) and calcined at different temperatures (200, 400, 600, 800, and 1000 °C) to obtain HAp with the highest purity. Subsequently, strontium-, magnesium-, and zinc-doped HAp powders were synthesized at the optimal pH value and calcination temperature. The HAp powder was then coated onto Ti disks using atmospheric plasma spraying (APS) or vapor-induced pore-forming atmospheric plasma spraying (VIPF-APS) techniques at different working currents (350, 400, and 450 A) and spraying distances (10 and 15 cm). X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy equipped with energy-dispersive spectroscopy were used for material characterization to determine the optimal parameters. With these optimal coating parameters, HAp, Zn-HAp, SrMg-HAp, and ZnSrMg-HAp powders were deposited onto the Ti disks using VIPF-APS and named HAp-Ti, Zn-HAp-Ti, SrMg-HAp-Ti, and ZnSrMg-HAp-Ti, respectively. The in vitro bioactivity of these four groups was evaluated using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and alkaline phosphatase (ALPase) activity assay. Besides, the antibacterial activities against Prevotella nigrescens, Porphyromonas gingivalis, and Fusobacterium nucleatum were assessed. The results showed that the purity of HAp synthesized at pH 10 and 800 °C was 98.40%. A porous coating without cracks was obtained at a 10 cm spraying distance and 400 A working current using VIPF-APS. SrMg-HAp-Ti and ZnSrMg-HAp-Ti resulted in higher osteoblast proliferation and ALPase activity than the control. Moreover, both Zn-HAp-Ti and ZnSrMg-HAp-Ti exhibited antibacterial activity against the three bacteria. Therefore, ZnSrMg-HAp has potential as a coating for biomedical materials due to its ability to reduce bacterial infection and enhance osseointegration.

Orf is an exanthemous viral disease seriously threatening the goat and sheep industry and widely epidemic in the goat and sheep populations in Xinjiang, China. In order to investigate the genetic variability of the orf virus (ORFV), three virus isolates (SHZ1, SHZ2, and SHZ3) were isolated by PCR and Vero cell culture using the clinical samples from the lips of the lambs suspected of ORFV infection. The isolates were further verified by electron microscopy and animal infection experiments. The protective antigen genes B2L, F1L, and virulence genes VIR, GIF, and VEGF in the isolates were cloned, sequenced and analyzed for genetic evolution. The results showed that B2L and F1L were relatively conservative with homology 86.7-97.9%, while VIR, GIF, particularly VEGF were considerably variable with homology 71.5-97.9% at amino acid sequence level, respectively. Phylogenetic tree analysis based on B2L and VIR showed that the isolates SHZ1 and SHZ2 were closely related with the Taiwan isolates. This is the first report to confirm that there have been genetic variations in the Xinjiang ORFV isolates. The findings provide molecular evidence about the genetic variability of the major antigenic and virulence genes in the virus isolates epidemic in Xinjiang.

When dealing with infectious pathogens, the risk of contamination or infection in the process of detecting them is nonnegligible. Separation-free detection will be beneficial in operation and safety. In this work, we proposed a DNAzyme walker for homogeneous and isothermal detection of enterovirus. The DNAzyme is divided into two inactivate subunits. When the subunit-conjugated antibody binds to the target virus, the activity of the DNAzyme recovers as a result of spatial proximity. The walker propels, and the fluorescence recovers. The final fluorescence intensity of the reaction mixture is related to the concentration of the target virus. The detection limit of this proposed method is 6.6 × 104 copies/mL for EV71 and 4.3 × 104 copies/mL for CVB3, respectively. Besides, this method was applied in detection of EV71 in clinical samples with a satisfactory result. The entire experiment is easy to operate, and the proposed method has great potential for practical use.

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