Assessment of the Development of Fine Motor Skills, Balance Function and Static Kinetic Stability in Elementary Schoolchildren

Background: Assessment of the development of fine motor skills (FMS), static balance (SB), and static kinetic stability (SKS) in elementary schoolchildren reflects the extent of their school readiness. Objective: To evaluate the development of children at the initial stage of systematic learning. Materials and methods: Fine motor skill tests were conducted in 117 children using a modified “Little House” technique; static balance was tested in 150 children using the stork pose balance test, and static kinetic stability was tested in 147 children by analyzing stability of the body standing while rotating around the vertical axis. Results: We established that fine motor skills were age appropriate in only 19.0 % (95 % CI: 8.9–29.1 %) of first and 17.0 % (95 % CI: 7.4–26.5 %) of second-year pupils. Low static kinetic stability was observed in 37.5 % (95 % CI: 25.6–49.4 %) of first graders and 38.8 % (95 % CI: 30.9–46.7 %) of second graders. The level of static balance was below the average in 65.7 % (95 % CI: 54.3–77.0 %) of first graders and 37.3 % (95 % CI: 26.9–47.8 %) of second graders. Developmental delays in FMS, SB and SKS were 1.2–3.9 times more frequent in boys than in girls. Conclusion: Our findings demonstrate that the development of FMS, SKS and SB in contemporary elementary schoolchildren is below the average level. The results may become the basis for elaboration of appropriate preventive programs and technologies in order to improve school readiness in children.

Biodegradable Amphoteric Surfactants in Titration-Ultrasound Formulation of Oil-in-Water Nanoemulsions: Rational Design, Development, and Kinetic Stability

Amphoteric amphiphilic compounds, due to their unique properties, may represent a group of safe and biocompatible surface-active agents for effective colloidal stabilization of nanoformulations. For this reason, the aim of this work was to develop and characterize the oil-in-water nanoemulsions based on two betaine-derived surfactants with high biodegradability, i.e., cocamidopropyl betaine and coco-betaine. In the first step, we investigated ternary phase diagrams of surfactant-oil-water systems containing different weight ratios of surfactant and oil, as the betaine-type surfactant entity (S), linoleic acid, or oleic acid as the oil phase (O), and the aqueous phase (W) using the titration-ultrasound approach. All the received nanoemulsion systems were then characterized upon droplets size (dynamic light scattering), surface charge (electrophoretic light scattering), and morphology (transmission electron as well as atomic force microscopy). Thermal and spinning tests revealed the most stable compositions, which were subjected to further kinetic stability analysis, including turbidimetric evaluation. Finally, the backscattering profiles revealed the most promising candidate with a size <200 nm for potential delivery of active agents in the future cosmetic, pharmaceutical, and biomedical applications.

SARS-CoV-2 variants exhibit increased kinetic stability of open spike conformations as an evolutionary strategy

ABSTRACTSARS-CoV-2 variants of concern harbor mutations in the Spike (S) glycoprotein that confer more efficient transmission and dampen the efficacy of COVID-19 vaccines and antibody therapies. S mediates virus entry and is the primary target for antibody responses. Structural studies of soluble S variants have revealed an increased propensity towards conformations accessible to receptor human Angiotensin-Converting Enzyme 2 (hACE2). However, real-time observations of conformational dynamics that govern the structural equilibriums of the S variants have been lacking. Here, we report single-molecule Förster Resonance Energy Transfer (smFRET) studies of S variants containing critical mutations, including D614G and E484K, in the context of virus particles. Investigated variants predominantly occupied more open hACE2-accessible conformations, agreeing with previous structures of soluble trimers. Additionally, these S variants exhibited decelerated transitions in hACE2-accessible/bound states. Our finding of increased S kinetic stability in the open conformation provides a new perspective on SARS-CoV-2 adaptation to the human population.