Disposable facemask waste combustion emits neuroactive smoke particulate matter.

Tremendous deposits of disposable medical facemask waste after the COVID-19 pandemic require improvement of waste management practice according to WHO report 2022, moreover facemasks are still in use around the world to protect against numerous airborne infections. Here, water-suspended smoke preparations from the combustion of disposable medical facemasks (polypropylene fibers) were collected; size, zeta potential, surface groups of smoke particulate matter were determined by dynamic light scattering, FTIR and Raman spectroscopy, and their optical properties were characterized. Neurochemical study using nerve terminals isolated from rat cortex revealed a significant decrease in the initial rate of the uptake/accumulation of excitatory and inhibitory neurotransmitters, L-[C]glutamate and [H]GABA, and exocytotic release, and also an increase in the extracellular level of these neurotransmitters.

Amphiphilic anti-SARS-CoV-2 drug remdesivir incorporates into the lipid bilayer and nerve terminal membranes influencing excitatory and inhibitory neurotransmission.

Remdesivir is a novel antiviral drug, which is active against the SARS-CoV-2 virus. Remdesivir is known to accumulate in the brain but it is not clear whether it influences the neurotransmission. Here we report diverse and pronounced effects of remdesivir on transportation and release of excitatory and inhibitory neurotransmitters in rat cortex nerve terminals (synaptosomes) in vitro.

A comparative study of wood sawdust and plastic smoke particulate matter with a focus on spectroscopic, fluorescent, oxidative, and neuroactive properties.

Here, water-suspended smoke aerosol preparation was synthesized from biomass-based fuel, i.e., a widespread product for residential heating, wood sawdust (WP) (pine, poplar, and birch mixture), and its properties were compared in parallel experiments with the smoke preparation from plastics (PP).

Characterization of thymine microcrystals by CARS and SHG microscopy.

Identification of chemically homologous microcrystals in a polycrystal sample is a big challenge and requires developing specific highly sensitive tools. Second harmonic (SHG) and coherent anti-Stokes Raman scattering (CARS) spectroscopy can be used to reveal arrangement of thymine molecules, one of the DNA bases, in microcrystalline sample. Strong dependence of CARS and SHG intensity on the orientation of the linear polarization of the excitation light allows to obtain high resolution images of thymine microcrystals by additionally utilizing the scanning microscopy technique.

Recognition of Spatial Distribution of CNT and Graphene in Hybrid Structure by Mapping with Coherent Anti-Stokes Raman Microscopy.

The shape of coherent anti-Stokes Raman scattering (CARS) spectral line depends on the ratio of the vibrational and electronic contributions to the third-order susceptibility of the material. The G-mode (1590 cm) of graphene and carbon nanotubes (CNTs) exhibits opposite features in the CARS spectrum, showing "dip" and "peak," respectively. Here, we consider the CARS spectra of graphene and carbon nanotubes in terms of Fano formalism describing the line shapes of CARS resonances.

Mechanochemical synthesis of carbon-stabilized Cu/C, Co/C and Ni/C nanocomposites with prolonged resistance to oxidation.

Metal-carbon nanocomposites possess attractive physical-chemical properties compared to their macroscopic counterparts. They are important and unique nanosystems with applications including in the future development of nanomaterial enabled sensors, polymer fillers for electromagnetic radiation shields, and catalysts for various chemical reactions. However, synthesis of these nanocomposites typically employs toxic solvents and hazardous precursors, leading to environmental and health concerns.

Heat Shock Proteins in the "Hot" Mitochondrion: Identity and Putative Roles.

The mitochondrion is known as the "powerhouse" of eukaryotic cells since it is the main site of adenosine 5'-triphosphate (ATP) production. Using a temperature-sensitive fluorescent probe, it has recently been suggested that the stray free energy, not captured into ATP, is potentially sufficient to sustain mitochondrial temperatures higher than the cellular environment, possibly reaching up to 50 °C. By 50 °C, some DNA and mitochondrial proteins may reach their melting temperatures; how then do these biomolecules maintain their structure and function? Further, the production of reactive oxygen species (ROS) accelerates with temperature, implying higher oxidative stresses in the mitochondrion than generally appreciated.

Liquid exfoliation of mechanochemically nanostructured tungsten disulfide to a graphene-like state.

The possibility of the efficient preparation of graphene-like 1H-WS by the primary solventless nanostructuration of bulk 2H-WS by means of its mechanochemical treatment in the presence of a chemically inert agent (NaCl) and the subsequent liquid exfoliation of the nanostructured 2H-WS in an organic solvent is shown for the first time. The shear stresses generated during the grinding of the WS/NaCl mixture caused the formation of WS particles with a reduced number of layers, while the stresses normal to their surface led to their cracking and a significant reduction in lateral size. The graphene-like morphology of the 1H-WS nanoparticles in the prepared dispersions is confirmed by atomic force microscopy and Raman spectroscopy.

Spectroscopic study of proflavine adsorption on the carbon nanotube surface.

Despite the fact that non-covalent interactions between various aromatic compounds and carbon nanotubes are being extensively investigated now, there is still a lack of understanding about the nature of such interactions. The present paper sheds light on one of the possible mechanisms of interaction between the typical aromatic dye proflavine and the carbon nanotube surface, namely, π-stacking between aromatic rings of these compounds. To investigate such a complexation, a qualitative analysis was performed by means of ultraviolet visible, infrared, and nuclear magnetic resonance spectroscopy.

p-Nitrobenzoic acid adsorption on nanostructured gold surfaces investigated by combined experimental and computational approaches.

Adsorption of guest molecules on host surfaces can lead to dramatic changes in the spectral properties of the guest. One such effect is surface-enhanced infrared absorption (SEIRA), observed when the guest is adsorbed on, for example, thin films, metal surfaces, or nanotubes. p-Nitrobenzoic acid (p-NBA) exhibits a SEIRA effect when adsorbed on Ag and Au.

Oxovanadium ions bind transfer RNA at multiple sites.

Oxovanadium compounds exert preventive effects against chemical carcinogenesis in animals and form complexes with DNA and RNA in vivo. This study was designed to examine the interaction of transfer RNA (tRNA) with VO(2+) and VO₃⁻ ions in aqueous solution at physiological pH, with constant a tRNA concentration of 12.5 mM and different vanadium/RNA (P) (P = phosphate) molar ratios (r) of 1:60 to 1:2.

Effect of a pH change on the conformational stability of the modified nucleotide queuosine monophosphate.

The naturally occurring modified nucleotide queuosine 5'-monophosphate (QMP) related to biochemical regulatory pathways in the cell was investigated using quantum chemical approaches. The relative stability of biologically relevant conformations of QMP in solvent under a pH change was predicted at the BVP86/TZVP and MP2/TZVP levels of theory. Hydrogen bonding in QMP was studied using Bader's approach.

Structural organisation of nucleic acids from tumour cells.

The DNA from Carcinoma Guerina resistant and sensitive cells of Wistar line rats and their interaction with anti-cancer drugs--cis-platin and doxorubicin (DOX)--have been studied in in vivo experiments. Surface enhanced infrared absorption (SEIRA) in reflectance absorption spectroscopy (RAS) mode was applied for registration of conformational change of the DNA induced by cancer process and anti-cancer drugs. We have registered numerous minor changes in infrared spectra of the DNA from sensitive and resistant cells that could reflect essential changes in molecular structure of DNA from cancer cells.