Analysis of energy state of a discrete fractionally one- and two -layer oscillatory spherical net model of mouse Zona Pelucida

As there are experimental evidences that Zona Pelucida (ZP) changes its elasticity during process of maturation we may supposed that ZP changes its oscillatory states as well. One of biological functions of this multi-layer mesh-like 3D structure that surrounds mammalian oocytes is selectivity regarding sperm penetration. On a basis of single-layered oscillatory spherical net model of mouse ZP (mZP) the improved double layer model is developed. Two new variables were included into the model: double-layered network and visco-elastic properties between its constructive elements. Due to visco-elastic properties of ZP and its importance for mechanism of sperm penetration double layered oscillatory net model of mZP has fractional order properties. Molecules in double-layered oscillatory mZP model are interconnected with standard light fractional order viscoelastic element defined by constitutive relation force - elongation expressed by fractional order derivatives. Oscillatory behavior of this double-layered system is discussed. As the sperm has to penetrate ZP it is of great importance what is the energy barrier it has to pass or what is the energy it has to own to fulfill the demands of ZP selection criteria. The energy states of one and double layered ZP oscillatory fractional order model of mZP are analyzed

STRUCTURE OF RELATIONS BETWEEN THE FREQUENCY OF MICRONUCLEI IN PERIPHERAL BLOOD LYMPHOCYTES AND AGE, GENDER, SMOKING HABITS AND SOCIO-DEMOGRAPHIC FACTORS IN SOUTH-EAST REGION OF SERBIA

Frequency of micronuclei (MN) in peripheral blood lymphocytes is a measure of genotoxicity and spontaneous chromosomal instability with many modifying factors. The aim of this work was to examine the relation between results of micronucleus test and set of socio-demographic parameters in healthy population in south-east Serbia using structure equation approach. Cytokinesis–block (CB) technique was used for analysis of MN frequency in peripheral blood lymphocytes on 133 healthy volunteers of various ages. Socio-demographic data was collected through a questionnaire. The mean frequency of MN gradually rose with age from 0.56±0.71 in new-borns to 5.48 ±3.65 in the 61-80 years age group (AG), with a decrease in the 81-92 years AG. MN frequency was positively correlated with age, altitude of birth place, altitude of place of residence, nuclear buds and nucleoplasmatic bridges, and negatively with education level and smoking habits. Linear structural model revealed age to be related to all of the examined variables, and indicates probable existence of another factor, independent of age, influencing all of these except nuclear buds. It can be concluded that the frequency of micronuclei is influenced by age and factor/s resembling socioeconomic status or lifestyle and this influence is independent of age

Oscillations and stability of dynamics of hybrid biostructure

Biostructures usually have complex geometrical organisation and oscillatory properties. Using a model of hybrid biostructure free and forced oscillatory modes and their stability regarding the geometrical and kinematic parameters of the model were analysed. The basic model of biostructure is in the form of complex cantilever of circular cross-section with rigidly connected structures and discrete masses and has three degree of freedom. For describing oscillatory behaviour of this hybrid biostructure, system of coupled differential equations and displacement influence coefficients of the cantilever were used. For specific geometrical parameters of the hybrid biostructure one unstable mode of free oscillations was identified. Amplitude-frequency graphs for forced oscillations for specific geometrical parameters for stable and unstable modes are presented. Conditions for resonance and dynamical absorption are discussed. Specific geometrical parameters of the hybrid biostructures can affect stability of their oscillations. Choosing specific geometrical forms in engineering design using biomimetic it is possible to reduced or eliminate undesirable oscillations

Multi-layer oscillatory spherical net model of mouse zona Pelucida

Zona Pelucida (ZP) is multi-layer mesh-like 3D structure that surrounds mammalian eggs. One of its biological functions is selectivity regarding sperm penetration. Oscillatory spherical net model of mZP is suitable for explain initial stadium of sperm penetration. This model is single-layer model. On a basis of single-layered oscillatory spherical net model of mZP we proposed improved double layer models. Due to visco-elastic properties of ZP and its importance for mechanism of sperm penetration double layered oscillatory net model of mZP has fractional order properties. Oscillatory behavior of this double-layered system is discussed

Influence of sperm impact angle on successful fertilization through mZP oscillatory spherical net model

According to the available literature, penetrating sperm creates an oblique path trough Zona pellucida (ZP) - the most outer surface of oocytes. Considering fertilization process as an oscillatory phenomenon, the influence of sperm impact angle relative to the oscillatory behavior of mouse ZP is described by using the discrete continuum mechanical model in the form of a spherical net model. A parametric frequency analysis of oscillatory behavior of knot material particles in the mouse ZP (mZP) spherical net model is conducted by using generalized Lussajous curves. The influence of impact angles of sperm cells on the corresponding knot mass particles' resultant trajectory is discussed. Favorable sperm impact angles for successful fertilization are identified

Importance of number of hyperactivated spermatozoa for successful fertilisation trough mechanical oscillatory model of mouse zona pellucida

The quality of a whole ejaculate is important for fertilization success. Number of sperm with effective swimming velocity, capable to reach the oocyte and to undergo complex adaptations within the female reproductive tract is a key determinant of male fertilization success. According to the literature, total sperm numbers are positively correlated to proportions of normal sperm, acrosome integrity and motile sperm and also with gonadosomatic index. Treating the fertilization process as an oscillatory phenomenon we use oscillatory spherical net model of mouse Zona Pellucida (mZP) to investigate the impact of sperm count on successful fertilization. To describe impact of number of hyperactivated sperm cells relative to the oscillatory behaviour of mZP, the discreet continuum model in the form of spherical net model is used. mZP is modelled as a discrete system of material particles (corresponds to mZP glycoproteins) interconnected with massless linear elastic elements on a manner that preserves molar ratio of m ZP glycoproteins. According to the model, under external numerous vibroimpacts of spermatozoa, mZP oscillatory net oscillates in forced regimes. To estimate the influence of sperm count a numerical analysis was conducted. Using generalized Lissajous curves, parametric frequency analysis of oscillatory behaviour of ZP1 molecules in oscillatory model of mZP is realized. Numerical analysis identified favourable oscillatory states of ZP1 molecules under the impact of different number of spermatozoa with effective velocity. We can conclude that ZP1 molecules in the mZP oscillatory model have different oscillatory states when exposed to the external vibro -impacts of different number of hyperactivated spermatozoa, indicated that certain number of hyperactivated spermatozoa is necessary for reaching the favourable oscillatory state of mZP for fertilisation.COBISS.SR-ID 20097793

Fertilisation as a Biomechanical Oscillatory Phenomenon in Mamals

Fertilization, the process of reunion of genetic material of oocyte and one sperm cell is well described on the biochemical level. In this paper we consider fertilization as a biomechanical oscillatory phenomenon. Using an oscillatory spherical net model of mouse ZP [4] we consider the resonance between forced oscillations of mouse Zona pelucida and impact of sperm cells as necessary condition for successful fertilization. To restate the resonance condition the numerical analysis were done