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Biomedical subjects

O V Kalmin

Publications and source records attributed to O V Kalmin.

8 recordsLinked to original sources
PubMed2001

[Tensile strength properties of lower limb nerves in the mature age].

Tensile strength and deformation properties of tibeal and common fibular nerves were analysed in 78 cadavers of both sexes people aged from 21 to 60. It was established that in mature age nerve tensile strength and elasticity increases with low extent of elongation. At the age from 21 to 50 tensile strength and rigidity decrease with significant deformations due to nerve fibre degeneration. After 50 ys tensile strength and rigidity grow higher due to the developing sclerosis of nerve trunks. The nerves studied posses equal tensile strength that decreases synchronously during the period of maturity. Changes of deformation and tensile strength properties of the nerves within the period of maturity is connected with age-related reorganization of their intratruncal structure. Diversities in mechanical properties of different nerves is determined by qualitative and quantitative peculiarities of their morphological structure.

Adult↗
PubMed1997

[The structural bases of the tensile strength properties of nerves].

Morphological and mechanical properties of phrenic and vagal nerves cervical regions were studied in 51 cadavers of fetuses and newborns in 28 to 40 weeks gestation. Diameter and thickness of coats, porting of cross section area occupied by connective tissue and general tensile strength were found to increase in both nerves with the gestation period growth, while relative share of nerve bundles cross section reduces. Within the last trimester of intrauterine development nerve trunk rigidity grows smaller and tensile strength does not change significantly. Vagal and phrenic nerves possess an elongation reserve, safe for their structure due to nerve fibers tortuosity. Connection between the nerve trunk rigidity coefficient and epineurium thickness, porting of cross section of nerve and connective tissue is non-linear and statistically significantly approximates with hyperbolic equation of order 1 or 3.

Gestational Age↗
PubMed1995

[The deformation-strength properties of the vertebral and common carotid arteries in fetuses and newborn infants].

General carotid and vertebral arteries of 51 corpses of foetuses and newborns with 28-40 weeks gestation were studied. The entire material was divided into 3 groups: 28-32 weeks, 33-36 weeks and 37-40 weeks. The thickness of the wall and its certain layers and connective tissue fibres architectonics were studied. General tensile strength, its limit, maximum relative deformation and the arterial wall Junge module were studied at longitudinal tension on ZM-40 tension machine. General carotid artery wall of foetuses and newborns is more tensile and has greater strength and less rigidity than that of the vertebral artery. The wall of the arteries studied has tensility reserve, safe for its structure in account of its fibroarchitectonics peculiarities. All the tensile strength parameters of the vessels investigated, with the exception of general carotid artery relative deformation, significantly change with the gestation increase. Tensile strength properties change depending on gestation term and body weight of foetuses and newborns may be approximated with linear function Y = A + B x X + C x Z (X--gestation term, Z--body weight).

Analysis of Variance↗
PubMedDate not supplied

[Mathematical modeling of the dynamics of structural thyroid parameters in thyroid disease with immune disorders].

The material of the study was surgical thyroid biopsies from 126 patients, males and females, aged 14-69 years. 5 groups were studied depending upon the histological picture and the degree of lymphoid infiltration. Thyroids from 10 persons without thyroid pathology who died a violant life served as control. As a result of the factor analysis 5 main factors were distinguished. The first one is lymphoid infiltration, the 2nd and 3rd ones-factors of thyroid epithelium characterizing the structure and the size of thyrocytes, the 4th and the 5th factors characterize the structure of the thyroid as an organ. The analysis confirmed lymphoid infiltration and thyrocyte dimensional parameters are the most important morphological criteria in the diagnosis of thyroid pathology with immune disturbances. Six equations are derived allowing to classify new cases of thyroid pathology.

Adolescent↗
PubMedDate not supplied

[The morphological characteristics and deformability and strength properties of the common carotid artery in fetuses and newborns].

General carotid arteries were studied in 51 corpses of foetuses and newborns with gestational ages ranging from 28 to 40 weeks. The entire material was divided into 3 groups: 1) 28-32 weeks, 2) 33-36 weeks, 3) 37-40 weeks. The length of the cervical region as well as external diameter of the artery, thickness of the wall and its certain layers, number of elastic membrane rows and connective tissue fibres architectonics were studied. General strength, its limits, maximum relative deformation and arterial wall Jung module were investigated at longitudinal extension in tension machine. All the arterial morphological and strength characteristics increase in proportion with gestation age but maximum accretion takes place by the end of the last month of intrauterine development. In all age groups vascular wall extensibility is almost equal. Arterial wall has an elongation reserve due to the wavy course of elastic fibres in tunica media.

Biomechanical Phenomena↗