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AbstractThis work is devoted to the study of plasma-chemical processes determined by the combination of the effect of thermally nonequilibrium, low-temperature plasma and intensive ultrasonic vibrations in the regime of intensive cavitation on liquid-phase media. This method for the realization of plasma-chemical transformations has been proven to be of significant interest and to have advantages for the creation of new nano-sized materials with special properties because it allows for varying the electrophysical and acoustic characteristics of the process when carrying out plasma-chemical reactions and fusion reactions. In this work, a novel facile technique for the synthesis of nanosized silver clusters in plasma discharge under ultrasonic cavitation is reported. Such a type of plasma involves the simultaneous effect of high-intensity cavitation and steady electric discharge in a liquid phase between electrodes of desired material. As a result, stable tiny silver nanoclusters with around a 1-nm size and a relatively narrow particle size distribution were obtained using toluene as a liquid medium. The nanoclusters were characterized with dynamic light scattering, transmission electron microscopy, electron diffraction, and optical methods. The results confirmed the formation of nanoclusters with an absorbance peak around 300 nm and the absence of 400-nm peaks typical for silver nanoparticles. Fluorescence tests allowed for establishing the amorphous structure of the synthesized nanoclusters occupying the intermediate position between few-atom nanoclusters and nanoparticles. The nanoclusters obtained were proven to be stable for more than 3 months. The experiments also revealed the possibility of performing high-temperature plasma-chemical reactions that can be applied in fusion technology.

Intercellular communication and transport is the essential prerequisite for the function of multicellular organisms. Simple diffusion as a transport mechanism is often inefficient in sustaining the effective exchange of metabolites, and other active transport mechanisms become involved. In this paper, we use the giant cells of characean algae as a model system to explore the role of advection and diffusion in intercellular transport. Using fluorescent dye as a tracer, we study the kinetics of the permeation of the fluorophore through the plasmodesmata complex in the node of tandem cells and its further distribution across the cell. To explore the role of cytoplasmic streaming and the nodal cell complex in the transport mechanism, we modulate the cytoplasmic streaming using action potential to separate the diffusive permeation from the advective contribution. The results imply that the plasmodesmal transport of fluorescent probe through the central and peripheral cells of the nodal complex is differentially regulated by a physiological signal, the action potential. The passage of the probe through the central cells of the nodal complex ceases transiently after elicitation of the action potential in the internodal cell, whereas the passage through the peripheral cells of the node was retained. A diffusion-advection model is developed to describe the transport kinetics and extract the permeability of the node-internode cell wall from experimental data.

In this study, plasma discharge in a liquid at intensive ultrasonic field above the cavitation threshold has been proven to be of great interest for initiation of various physical and chemical processes. In such discharge, nanoparticles of tungsten and zinc oxides have been synthesised. Further exploration of synthesised nanoparticles has demonstrated that the factor of ultrasonic cavitation during the synthesis substantially affects physical and chemical characteristics of nanoparticles.

The surface modification of titanium dioxide in aqueous dispersions of specially tailor-made periodic acrylic acid/isobutylene copolymers, poly(acrylic acid)/polystyrene graft copolymers, and hydrophobically modified polyethyleneoxide urethane by ultrasonic treatment was studied. The pigment surface modification by the above copolymers was comparatively investigated regarding conventional adsorption as contrasted to an ultrasonic treatment assisted procedure. The course and efficiency of the polymer adsorption onto the pigment surface was quantified by electrokinetic sonic amplitude measurements. The higher efficiency of the pigment surface coating by the copolymers as achieved by ultrasonic treatment varies with the copolymer architecture and is a consequence of ultrasonically induced pigment surface activation.

The effect of structural memory in a wave field has been exemplarily studied by the IR-spectroscopy method on films made from mixtures of butadiene-styrene and acrylic latex as models of polymeric membranes. The strengthening of the interphase interaction in heterophase systems that can cause change of their local and transmitting mobility has been observed. It has been shown, that the response of polymeric dispersed systems and compositions on influence of nonlinear vibrations proves their influence on deformation properties, like orientation phenomena in solid polymers (where Rebinder's effect can take place) that it is possible to consider as a way of polymer modifications, including the obtaining of nanocomposites, polymeric biocarriers, etc.

The initial stage of gelation of organic-inorganic hybrid hydrogels based on poly(N-vinylpyrrolidone) and the products of hydrolytic polycondensation of tetramethoxysilane has been studied by capillary viscometry. The development of strong bonds between polymer molecules and silica particles in aqueous solutions is proved by the electrokinetic sonic amplitude method. The molecular mass of poly(N-vinylpyrrolidone), the concentration of starting components, and their total amount affect the onset time of gelation in poly(N-vinylpyrrolidone)-water-tetramethoxysilane systems. The general scheme of formation of three-dimensional networks in such systems under the conditions of mutual penetration of poly(Nvinylpyrrolidone) coils is suggested. According to this scheme, nanoparticles of the general formula SiOx(OH)y(OR)z linking poly(N-vinylpyrrolidone) macromolecules serve as junctions of the gel network due to the formation of hydrogen bonds between hydrogens of silanol groups of organosilanes and oxygens of carbonyl groups of poly(N-vinylpyrrolidone).

The success of mRNA-based therapies depends on the availability of a safe and efficient delivery vehicle. Lipid nanoparticles have been identified as a viable option. However, there are concerns whether an acceptable tolerability profile for chronic dosing can be achieved. The efficiency and tolerability of lipid nanoparticles has been attributed to the amino lipid. Therefore, we developed a new series of amino lipids that address this concern. Clear structure-activity relationships were developed that resulted in a new amino lipid that affords efficient mRNA delivery in rodent and primate models with optimal pharmacokinetics. A 1-month toxicology evaluation in rat and non-human primate demonstrated no adverse events with the new lipid nanoparticle system. Mechanistic studies demonstrate that the improved efficiency can be attributed to increased endosomal escape. This effort has resulted in the first example of the ability to safely repeat dose mRNA-containing lipid nanoparticles in non-human primate at therapeutically relevant levels.

Stimulated Rayleigh–Mie scattering (SRMS) in two-photon absorption liquids is realized by a Fourier-transform-limited pulsed Nd-glass laser. For the first time, to the best of our knowledge, we have measured anti-Stokes spectral shifts of SRMS in toluene and hexane colloids of Ag nanoparticles, as well as in pure toluene. These values appreciably exceed the Rayleigh line width in those liquids. The four-wave mixing method is applied both experimentally and theoretically to display the process as Rayleigh-induced parametric generation. We show that the amplification effect is provided predominantly by thermally induced coherent polarization oscillations, while an interference-assisted thermal grating provides formation of a self-induced optical cavity inside the interaction region.

Recently, the World Health Organization confirmed 120 new human cases of avian H7N9 influenza in China resulting in 37 deaths, highlighting the concern for a potential pandemic and the need for an effective, safe, and high-speed vaccine production platform. Production speed and scale of mRNA-based vaccines make them ideally suited to impede potential pandemic threats. Here we show that lipid nanoparticle (LNP)-formulated, modified mRNA vaccines, encoding hemagglutinin (HA) proteins of H10N8 (A/Jiangxi-Donghu/346/2013) or H7N9 (A/Anhui/1/2013), generated rapid and robust immune responses in mice, ferrets, and nonhuman primates, as measured by hemagglutination inhibition (HAI) and microneutralization (MN) assays. A single dose of H7N9 mRNA protected mice from a lethal challenge and reduced lung viral titers in ferrets. Interim results from a first-in-human, escalating-dose, phase 1 H10N8 study show very high seroconversion rates, demonstrating robust prophylactic immunity in humans. Adverse events (AEs) were mild or moderate with only a few severe and no serious events. These data show that LNP-formulated, modified mRNA vaccines can induce protective immunogenicity with acceptable tolerability profiles.

There is currently no animal model to evaluate the preventive efficacy of antiviral drugs for the treatment of smallpox in human patients with a weak immune system. Therefore, the possibility of using outbred severe combined immunodeficiency (SCID) mice as an animal model was examined by electron microscopy and virological, histological, and statistical methods. There were no clinical signs of disease after the intranasal infection of mice with the variola virus (VARV) at a dose of 5.2 log10PFU (plaque forming unit). At the same time, the median infective dose (ID50) of VARV estimated by registering the presence of the virus in the lungs of animals four days after infection was 3.5 log10PFU, and thus, was close to that theoretically determined in human patients by identifying the clinical picture of the disease. The reproduction of the virus was detected only in the respiratory organs of mice infected with VARV at a dose of 5.2 log10PFU (50 ID50). The values of the VARV concentration in the lungs and nose were similar to those observed in human patients and well-known animal models such as Macaca cynomolgusand ICR mice respiratorily infected with almost the same doses of VARV. The known animal models were not shown to be significantly different from SCID mice in terms of the duration of the presence of the virus in the lungs. Moreover, the inflammatory and necrotic pathomorphological changes observed in the respiratory organs of SCID mice were similar to those occurring in other animal models and human patients. The use of SCID mice for evaluating the preventive efficacy of the NIOCH-14 and ST-246 antiviral drugs led to the results agreeing well with the previously reported data. Thus, SCID mice may be used as an experimental animal model for simulating smallpox to develop antiviral drugs for the treatment of human patients with a severe immunosuppressive state.

Abstract: An electronic databank including the results of seismic investigations and schemes of the sediment thickness’s distribution patterns was built up for two seismostratigraphic complexes in the Falkland Basin. The interface’s border was dated, and the sedimentation rates were estimated for each complex. An integrated map of the cumulative thickness of the deposits and sedimentation rates was developed. The lowest limits of the parameters of the sedimentation process were characterized for the sedimentary layers affected by compaction and erosion.

The structure of adsorption layers of amphiphilic block and blocklike copolymers of polyisobornyl acrylate and polyacrylic acid on the surface of hydrophilic titanium dioxide and hydrophobic copper phthalocyanine CuPc pigments in an aqueous dispersion has been studied by the electrokinetic sonic amplitude ESA method. The electroacoustic behaviour of the polyelectrolyte block copolymercoated particles could be described in the context of the polymer gel layer theory. The polymer layer around the particles was found to be much thinner for CuPc as compared to the TiO2substrate. This is attributed to differences in the adsorption mechanism and the composition of the adsorption layer normal to the substrate surface. Adsorption models were established that consider effects of the copolymer structure.