arXiv subjects

Alexander Kholmanskiy

Publications and source records attributed to Alexander Kholmanskiy.

6 recordsLinked to original sources

arXiv2023

Role of water in physics of blood and cerebrospinal fluid

Known physical mechanisms of temperature dependence anomalies of water properties were used to explain the regularities in temperature dependence (TDs) of dynamic, electrical and optical characteristics of biological systems. The dynamics of hydrogen bonds in bulk and hydrated water affected the activation energies TDs of ion currents of voltage-dependent channels that regulate signaling and trophic bonds in the neuropil of the cortical parenchyma. The physics of minimizing the TD of the isobaric heat capacity of water made it possible to explain the stabilization and functional optimization of the thermodynamics of eyeball fluids at 34.5 C and the human brain during sleep at 36.5 C. At these temperatures, the thermoreceptors of the cornea and the cells of the ganglionic layer of the retina, through connections with the suprachiasmatic nucleus and the pineal gland, switch the circadian rhythm from daytime to nighttime. The phylogenesis of the circadian rhythm was reflected in the dependence of the duration of the nighttime sleep of mammals on the diameter of the eyeball and the mass of the pineal gland. The activity of all the nerves of the eyeball led to the division of the nocturnal brain metabolism into NREM and REM phases. These phases correspond to two modes of the glymphatic system - electrochemical and dynamic. The first is responsible for the relaxation processes of synaptic plasticity and chemical neutralization of toxins with the participation of water and melatonin. Rapid eye movement and an increase in cerebral blood flow in the second mode increase water exchange in the parenchyma and flush out toxins into the venous system. Electrophysics of clearance and conductivity of ionic and water channels of membranes of blood vessels and astrocytes modulate oscillations of polarization potentials of water dipole domains in parietal plasma layers of arterioles and capillaries.

physics.bio-ph↗

arXiv2021

Synergism of the dynamics of tetrahedral hydrogen bonds of liquid water

We used modified Arrhenius approximations to analyze the known temperature dependences (TDs) of water microstructure parameters and its dynamic characteristics. The analysis of activation energies showed a significant difference in the molecular dynamics (MD) of water in the ranges from 273 to 298 K and from 300 to 373 K. The features of MD in the first range were associated with the metastable ice-like phase of water, in which hexagonal clusters with tetrahedral hydrogen bonds (HBs) predominate. Based on the ratios of the signs and values of the activation energies of HBs fluctuations and the parameters of the microstructure, it was assumed that fluctuations of HBs dipoles play a key role in the mechanism of resonant activation by thermal energy of consistent reactions of deformation, rupture and formation of tetrahedral HBs in water clusters. The synergism of these reactions and the interaction of the charges of the vacant acceptor and donor tetrahedral orbitals of the oxygen atom trigger at 298 K an explosive transition of the metastable ice like phase of water into the argon like phase. The synergetics of water dynamics above 298 K is adequately characterized by the product diffusion on viscosity, from which TDs follow the activation energies of reactions that determine the form of the Stokes Einstein relation in the temperature ranges below and above the 298 K point.

physics.chem-ph↗

arXiv2020

Comment on: Describing temperature-dependent self-diffusion coefficients and fluidity in alcohols using the compensated Arrhenius formalism

In Supplemental Information (SI) to the article [A. M. Fleshman, G. E. Forsythe, M. Petrowsky, R. Frech, J. Phys. Chem. B 2016, 120, 37, 9959-68] the temperature dependences (TDs) of the dielectric and dynamic properties of polyhydric alcohols, as well as the activation energy (Ea) obtained using the compensated Arrhenius formalism (CAF) are given. The authors present CAF as an approach provides physical significance into the molecular level nature of the transport process. However, the CAF logic is physically inadequate and analysis of TDS polyhydric alcohols using CAF cannot provide physically significant correlations useful for understanding the molecular mechanisms of fluid dynamics. However, such correlations from SI can be obtained by applying physically adequate Arrhenius approximations of TDs properties of liquids [A. Kholmanskiy, N. Zaytseva, J. Mol. Liq. 275 (2019) 741-8].

physics.flu-dyn↗

arXiv2020

Supramolecular physics of ambient water

In temperature range from 0 C to 100 C, abnormality of ambient water properties, at normal pressure, are mainly defined by the physic of hydrogen bonds in supramolecular structures (SMS). Application of Arrhenius approximations and modification of temperature dependences (TDs) for 15 physical characteristics of water made it possible to define their activation energies and to differentiate the contributions of equilibrium thermal processes and those of SMS reconfigurations. Reactions of hydrogen bonds breakage and those of hexagonal ice-like clusters transformation limit TDs of viscosity and rotation-translational self-diffusion. Limitation of degrees of freedom of these motions by the effect of anisotropic external factors leads to the reduction of activation energy for TDs of compressibility, sound velocity and thermal conductivity nearly sixfold. Equality of absolute values of activation energies, having opposite signs, for the thermal and configurational components of TDs, in its point of extremum, is the condition of TDs extrema for volumetric density, heat capacity at constant pressure, compressibility and sound velocity. In this case, space time correlation of water dynamics takes place on the supramolecular level, followed by constant-energy transition between metastable SMS phases.

physics.chem-ph↗

arXiv2020

Activation energies of water molecular dynamics and Stokes-Einstein equation

An analysis of the values and signs of the activation energies of temperature dependences (TDs) of the self-diffusion coefficient (D) and dynamic viscosity (η) in the range from 0 °C to 100 °C confirmed that the molecular dynamics of water is based on the synergism of endo and exo reactions of rearrangement of hydrogen bonds in the supramolecular structure water. The ratio of linear approximation coefficients TD of the complex characteristic Dη before and after 25 °C correlates with the ratio of cluster sizes prevailing in the water structure in these temperature ranges. This result is consistent with the Stokes-Einstein equation and the hypothesis that the decomposition of hexagonal ice-like clusters is completed in the vicinity of 25 °C. A reliable approximation of the TD complex Dη by a bimodal function of type Texp (E/RT) was used to refine the Stokes-Einstein equation.

physics.flu-dyn↗

arXiv2020

Dependence of chlorophyll content in leaves from light regime, electromagnetic fields and plant species

The regularity of the distribution of chlorophylls content in a series of 30 cultivated plants and 75 steppe grasses was studied. The increased content of chlorophyll and magnesium in vegetables and grains compared with greens and steppe grasses is associated with more complex genetics of metabolism, which has stages of flowering and fruiting. The chlorophyll content increases with the use of LED phytoirradiators with an emission band coinciding with the first absorption band of chlorophyll. Industrial electromagnetic fields can affect the biosynthesis of pigments in deciduous trees, but cultivated herbaceous plants are not sensitive to them.

q-bio.OT↗