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Despite the rapid development and approval of several COVID vaccines based on the full-length spike protein, there is a need for safe, potent, and high-volume vaccines. Considering the predominance of the production of neutralizing antibodies targeting the receptor-binding domain (RBD) of S-protein after natural infection or vaccination, it makes sense to choose RBD as a vaccine immunogen. However, due to its small size, RBD exhibits relatively poor immunogenicity. Searching for novel adjuvants for RBD-based vaccine formulations is considered a good strategy for enhancing its immunogenicity. Herein, we assess the immunogenicity of severe acute respiratory syndrome coronavirus 2 RBD conjugated to a polyglucin:spermidine complex (PGS) and dsRNA (RBD-PGS + dsRNA) in a mouse model. BALB/c mice were immunized intramuscularly twice, with a 2-week interval, with 50 µg of RBD, RBD with Al(OH)3, or conjugated RBD. A comparative analysis of serum RBD-specific IgG and neutralizing antibody titers showed that PGS, PGS + dsRNA, and Al(OH)3 enhanced the specific humoral response in animals. There was no significant difference between the groups immunized with RBD-PGS + dsRNA and RBD with Al(OH)3. Additionally, the study of the T-cell response in animals showed that, unlike adjuvants, the RBD-PGS + dsRNA conjugate stimulates the production of specific CD4+ and CD8+ T cells in animals.

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.

Late Miocene continental deposits overlying the Khersonian marine sediments near the city of Maikop bordering the Belaya River (North Caucasus) yielded a diverse biotic record including palynology, ostracods, fresh-water and terrestrial molluscs, fishes, amphibians and reptiles, birds, and mammals. The obtained data indicate predominantly wooded landscapes along the banks of a large fresh-water estuarine or lagoonal basin with occasional connection with the sea. The basin existed in a warm temperate to subtropical climate with a high humidity and an estimated mean annual precipitation above 800 mm. The mammalian assemblage with Hipparion spp., Alilepus sp., Paraglirulus schultzi, Eozapus intermedius, Parapodemus lugdunensis, Collimys caucasicus sp. nov., Neocricetodon cf. progressus, etc. is referable to the early Turolian, MN 11. The data regarding composition and stage of evolution of the small mammal content combined with mostly normal polarity of the fossiliferous deposits, and the age estimates of the upper Khersonian boundary as between 8.6 and 7.9 Ma indicate a plausible correlation with Chron C4n and an age range between 8.1–7.6 Ma.

Background A plethora of noninvasive approaches has been developed in recent years for facial rejuvenation. Energy-based devices have been one of the most popular treatments for reversing and preventing signs of facial aging such as fine lines, wrinkles, ptosis, and photoaging. Aims A new technology (RecoSMA) for skin rejuvenation based on acoustic-interference method using Er:YAG laser (2936 nm) equipped with a special module that targets both the dermis and the superficial musculoaponeurotic system (SMAS) was recently demonstrated to be safe and effective in facial rejuvenation. Patient/methods In this follow-up prospective study, the clinical effects of recoSMA treatment on skin structures and SMAS were evaluated with ultrasound and histological analysis, at 30 and 90 days posttreatment. Results Treatment with recoSMA was shown to result in a significant increase in thickness of the epidermis, dermis, and SMAS layer, while levels of collagen I, III, and IV were shown to be elevated at 90 days posttreatment. Conclusion Collectively, data show that treatment with recoSMA laser has a profound biological effect in stimulating and reconstructing the elastin/collagen framework necessary for preventing facial aging.

The evolutionary history of the extant buttonquails (family Turnicidae) is poorly known. The Oligocene stem representatives of the family differ significantly morphologically from the extant members of Turnicidae and presumably had different ecology and lifestyle. Until now, the only pre-Pleistocene record of the crown-group buttonquails was a find in the Pliocene of South Africa—within the modern distribution range of the group. Here we describe remains of the modern-type Turnicidae from the late Miocene of Hungary, Southern Ukraine, and Northern Kazakhstan. These finds show that Turnicidae, which nowadays are restricted to the subtropical and tropical regions, had much wider geographical distribution in the late Miocene. This range expansion might have been related to the wide spread of the open and arid landscapes during the late Miocene. Importantly, all remains described herein are morphologically similar to the living genus Ortyxelos, which has been considered primitive and now inhabits arid landscapes in Africa. The genus Ortyxelos is thus likely yet another (along with ostrich and some mammals) taxon which now inhabits sub-Saharan Africa, but once had a much wider distribution across Eurasia.