Currently, SARS-CoV-2 spike receptor-binding-domain (RBD)-based vaccines are considered one of the most effective weapons against COVID-19. During the first step of assessing vaccine immunogenicity, a mouse model is often used. In this paper, we tested the use of five experimental animals (mice, hamsters, rabbits, ferrets, and chickens) for RBD immunogenicity assessments. The humoral immune response was evaluated by ELISA and virus-neutralization assays. The data obtained show hamsters to be the least suitable candidates for RBD immunogenicity testing and, hence, assessing the protective efficacy of RBD-based vaccines.

Cadmium sulfide was prepared by colloidal synthesis in methyl methacrylate (MMA). Europium and terbium salts were added to the colloidal solutions. Using MMA radical polymerization, we synthesized PMMA/CdS:Eu(III), PMMA/CdS:Tb(III), and PMMA/CdS:Eu(III):Tb(III) luminescent composites. Their luminescence is due to defects in the CdS crystals and the ⁵D_о → 7Fj and ⁵D₄ → ⁷F_j electronic transitions of the Eu³⁺ and Tb³⁺ ions, respectively. It depends on the composition of the materials, complexation on the surface of the colloidal particles, heat treatment time during synthesis, excitation wavelength, and other factors.

Quantum dots (QDs) synthesized by combining semiconductors are characterized by more stable optical properties. Introducing them into polymeric matrices can lead to optical compositions with...

Nanosized cadmium sulfide particles (quantum dots; QDs) were synthesized in ethylacetate and (poly)methylmethacrylate by the reaction between cadmium trifluoroacetate and H2S formed by the hydrolysis...

Optically transparent polymeric materials PMMA: Cd(Pb)S have been synthesized by polymerization of methyl methacrylate, which concurrently acts as a reaction medium for synthesis of metal sulfides, dispersion medium for the resulting colloidal solution forming during synthesis, and the base of compositions. Dependences of cadmium sulfide luminescence on the concentrations, concentration ratios of the initial compounds, reaction medium composition, and temperature have been established. The observed changes in the spectra are related to the introduction of lead(II) into compositions, complex formation on the surface of colloidal particles, and the effect of polar acetonitrile.