Anomalous diffusion, gigahertz, and terahertz spectroscopy of aliphatic ketones.

The experimental results of the complex dielectric permittivity of aliphatic ketones in dilute solutions of inert solvent cyclohexane in the gigahertz (GHz) and terahertz (THz) frequencies of the electromagnetic spectrum are examined in terms of the theory of inertial anomalous diffusion of polar molecules, considered as an assembly of molecules with interacting dipolar groups, in polar liquids. The theory is based on the generalization of the Debye rotational diffusion model of dielectric relaxation of polar molecules. The model comprises two interacting dipolar groups-one lighter and the other heavier; each has a finite moment of inertia and each experiences a finite friction with an extensive range of damping or drag coefficient and the dipole moment ratio of the two groups. The lighter group refers to the reference molecule, whereas the heavier group simulates the neighboring molecules, and the two groups interact with each other via the dipole-dipole interaction potential. The resulting approximate expression contains terms in both the Rocard form and the Сole-Сole form. The experimental data on aliphatic ketones are shown to fit extremely well with the theory, and parameters of the fit offer physical significance. An agreement of the plot of the experimental data on dielectric loss versus frequency to the formulas derived from the model offers a mathematical basis of the semiempirical equations used in the literature to fit the experimental data. Experimental results of the dielectric loss of neat polar liquid acetone in GHz and THz, as an example, are shown to fit the theory; however, the interaction potential parameter compared to its dilute solution counterpart is significantly increased, reflecting the increase in the dipole-dipole interaction energy.

Coupled physical and magnetodynamic rotational diffusion of a single-domain ferromagnetic nanoparticle suspended in a liquid.

A concise operator form of the Fokker-Planck equation agreeing with that proposed by Weizenecker [Phys. Med. Biol. 63, 035004 (2018)10.1088/1361-6560/aaa186] for the joint orientational distribution of the coupled physical and magnetodynamic rotational diffusion of a single-domain ferromagnetic nanoparticle suspended in a liquid is written from the postulated Langevin equations for the stochastic dynamics. Series expansion of its solution in a complete set yields, using the theory of angular momentum, differential-recurrence equations for statistical moments for coupled motion with uniaxial symmetry of the internal anisotropy-Zeeman energy of a nanoparticle. The numerical results via the matrix iteration method suggest that the susceptibility is adequately approximated by a single Lorentzian with peak frequency given by the inverse integral relaxation time and are discussed in relation to those of the well-known "egg model".

Anomalous diffusion of molecules with rotating polar groups: The joint role played by inertia and dipole coupling in microwave and far-infrared absorption.

Budó's generalization [A. Budó, J. Chem. Phys. 17, 686 (1949)10.1063/1.1747370] of the Debye rotational diffusion model of dielectric relaxation of polar molecules to an assembly with internal interacting polar groups is extended to inertial anomalous diffusion. Thus, the theory can be applied both in the GHz and the THz regions, accounting for anomalous behavior as well as the necessary return to optical transparency at very high frequencies. The linking of both dispersion regions in a single model including anomalous effects is accomplished via a fractional Fokker-Planck equation in phase space based on the continuous time random walk ansatz. The latter is written via the Langevin equations for the stochastic dynamics of pairs of interacting heavy polar groups embedded in the frame of reference of a particular molecule or molecular dimer rotating about a space-fixed axis. The fractional Fokker-Planck equation is then converted to a three-term matrix differential recurrence equation for the statistical moments. This is solved in the frequency domain for the linear dielectric response using matrix continued fractions. Thus, one has the complex susceptibility χ(ω) for extensive ranges of damping, group dipole moment ratio, and friction. The susceptibility, as inferred from the small oscillation limit, inherently comprises a low frequency (GHz) band with width depending on the anomalous parameter and a far-infrared (THz) or Poley peak of resonant character with a comblike structure of harmonic peaks. This behavior is due to the double transcendental nature of the after-effect function.

Anomalous diffusion of a dipole interacting with its surroundings.

A fractional Fokker-Planck equation based on the continuous time random walk Ansatz is written via the Langevin equations for the dynamics of a dipole interacting with its surroundings, as represented by a cage of dipolar molecules. This equation is solved in the frequency domain using matrix continued fractions, thus yielding the linear dielectric response for extensive ranges of damping, dipole moment ratio, and cage-dipole inertia ratio, and hence the complex susceptibility. The latter comprises a low frequency band with width depending on the anomalous parameter and a far infrared (THz) band with a comb-like structure of peaks. Several physical consequences of the model relevant to anomalous diffusion in the presence of interactions are discussed. The entire calculation may be regarded as an extension of the cage model interpretation of the dynamics of polar molecules to anomalous diffusion, taking into account inertial effects.

Cage model of polar fluids: Finite cage inertia generalization.

The itinerant oscillator model describing rotation of a dipole about a fixed axis inside a cage formed by its surrounding polar molecules is revisited in the context of modeling the dielectric relaxation of a polar fluid via the Langevin equation. The dynamical properties of the model are studied by averaging the Langevin equations describing the complex orientational dynamics of two bodies (molecule-cage) over their realizations in phase space so that the problem reduces to solving a system of three index linear differential-recurrence relations for the statistical moments. These are then solved in the frequency domain using matrix continued fractions. The linear dielectric response is then evaluated for extensive ranges of damping, dipole moment ratio, and cage-dipole inertia ratio and along with the usual inertia corrected microwave Debye absorption gives rise to significant far-infrared absorption with a comb-like structure of harmonic peaks. The model may be also regarded as an extension of Budó's [J. Chem. Phys. 17, 686 (1949)] treatment of molecules containing rotating polar groups to include inertial effects.

[TISSUE-ENGINEERED SUBSTITUTION URETHROPLASTY BASED ON DECELLULARIZED VASCULAR MATRIX AND AUTOLOGOUS CELLS OF THE BUCCAL MUCOSA: THE FIRST EXPERIENCE].

Urethral strictures and anomalies remain a challenging urological problem. Reconstructive plastic surgery has been shown to be the most effective way to treat them. There are two main types of urethroplasty: anastomosis (anastomotic urethroplasty) and expansion of the urethral lumen using of flaps and grafts (substitution urethroplasty). Currently the ideal material for substitution urethroplasty does not exist. Tissue engineering of the urethra seems to be one of the most promising approaches to address this problem. Various tissues-engineering techniques were proposed for substitution urethroplasty. In this study, tissue-engineering design was based on the decellularized cadaveric arterial wall. The study results demonstrated the feasibility of creating stable tissue-engineered structures with autologous cultured epithelial cells of the buccal mucosa and decellularized matrix from human cadaveric arterial wall (DMCAW). There was a complete engraftment of tissue-engineering design based on DMCAW and buccal mucosa cells, used for substitution urethroplasty in a patient with the bulbar urethral stricture. Postoperatively (within 4 months after surgery) no complications and/or adverse events were observed. However, in the late postoperative period (12 months) there was recurrence of urethral stricture in the middle of the tissue-engineering design and the native urethra that warranted another surgery. Tissue-engineering design based on DMCAW and autologous buccal mucosa is safe as a material for substitution urethroplasty. Further research is required to ascertain the effectiveness of the method.

[URETERAL TISSUE ENGINEERING: CHALLENGES AND PROSPECTS].

A broad range of pathologic conditions of the ureter (strictures, obliterations, fistulas, and so on) requiring reconstructive plastic surgery is a challenging urological problem. A variety of approaches to solve the problem indicates the need of searching for new opportunities. A new direction in reconstructive surgery of the ureter is the tissue engineering. Tissue engineering involves the usage of matrices and cells. The matrices can be used both with cultured cells, and without them. This review represents the results of preclinical studies on feasibility of tissue engineering using as a matrix both natural and synthetic materials for different ureter impairments. Presently, there are no data on the use of tissue-engineering for the ureter reconstruction in clinical trials (i.e. involving human subjects). The results of studies presented in the review inspire certain optimism, but ureteral tissue-engineering is a difficult task requiring a balanced approach and well-thought-out design of preclinical studies.

[Experimental validation of the developing a matrix based on decellularized vascular wall for subsequent substitution urethroplasty].

Urethral strictures are urgent urological problem. Anastomotic and substitution urethroplasty are the most effective treatments. For substitution urethroplasty, buccal mucosa is most often used. There are the following difficulties associated with the substitution urethroplasty: complications in the donor area, the lack of tissue for substitution, an additional incision, and increased timing of surgery due to the need to obtain a flap or graft. Tissue engineering can be useful in solving the above problems. Tissue engineering involves the use a matrix without cells and matrix with one or more types of cells (tissue-engineering designs). In our study we have evaluated the ability to create a matrix for the substitution urethroplasty in animal experiments. The decellularized cadaveric arterial wall was used as a matrix. Decellularization was performed using enzymatic method. At the first stage, we transplanted matrix fragments in interscapular region in rats. An extremely weak bioactivity dof decellularized matrix of cadaveric arterial wall (DMCAW) due to the low immunogenicity of the material was revealed. Thus resorption of DMCAW was quite slow (60-90 days). At the second stage, in an experiment on rabbits, substitution urethroplasty using tubular DMCAW was successfully performed. Intraoperative urethral defect up to 1.8 cm was created, which was replaced by a tubular DMCAW. The use of this type of matrix has showed good structural and functional results: urethral strictures did not arise, the rejection of the matrix was not observed. A slow degradation of the matrix and progressive epithelialization of onnective tissue capsule were revealed. Decellularized matrix based on cadaveric arterial wall can be considered as a material for substitution urethroplasty.

[Immunologic criteria of health changes caused by chemicals polluting environment in infants and pregnant women]. / Immunologicheskie kriterii vliianiia khimicheskikh zagriaznitelei okruzhaiushchei sredy na zdorov'e beremennykh zhenshchin i detei pervogo goda zhizni.

The authors revealed relations-hip between pregnancy disorders and changed humoral immunity parameters including production of anti-hapten antibodies to chemical pollutants (formaldehyde, nickel and lead). The authors disclosed reliable correlations between immune disorders in pregnancy and specific diseases in newborns and infants.

[Influence of work conditions and climate factors on respiratory diseases prevalence among workers of Northern regions]. / Vliianie uslovii truda i klimaticheskikh faktorov na rasprostranennost' boleznei organov dykhaniia u rabotaiushchikh na Severe.

The article deals with study covering influence of industrial and climate hazards on respiratory diseases prevalence among workers of wash-house situated in cool climate, with search of the most informative values for organization of social and hygienic monitoring. The results proved that the controlled values should include not only dust load and ambient air temperature, but also "duration of work in ambient air speed over allowable value", "duration of work in ambient air humidity over allowable value", "length of service in North" and "climate area of previous dwelling".