scholarly journals Stress-free state of the red blood cell membrane and the deformation of its skeleton

2012 ◽  
Vol 17 (2) ◽  
Author(s):  
Tjaša Švelc ◽  
Saša Svetina
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Variational Calculation ◽  
Lateral Distribution ◽  
Free State ◽  
Initial State ◽  
Proposed Model ◽  
Deformed State ◽  
Concentric Circles ◽  
Stress Free State

AbstractThe response of a red blood cell (RBC) to deformation depends on its membrane, a composite of a lipid bilayer and a skeleton, which is a closed, twodimensional network of spectrin tetramers as its bonds. The deformation of the skeleton and its lateral redistribution are studied in terms of the RBC resting state for a fixed geometry of the RBC, partially aspirated into a micropipette. The geometry of the RBC skeleton in its initial state is taken to be either two concentric circles, a references biconcave shape or a sphere. It is assumed that in its initial state the skeleton is distributed laterally in a homogeneous manner with its bonds either unstressed, presenting its stress-free state, or prestressed. The lateral distribution was calculated using a variational calculation. It was assumed that the spectrin tetramer bonds exhibit a linear elasticity. The results showed a significant effect of the initial skeleton geometry on its lateral distribution in the deformed state. The proposed model is used to analyze the measurements of skeleton extension ratios by the method of applying two modes of RBC micropipette aspiration.

ESTIMATION OF HEMOGRAMS INDICES IN PERSONS OF THE ORGANIZED GROUP IN EXTREME CONDITIONS WHEN IN THE DIET INCLUDED PRODUCTS PRODUCED BY CRYOGENIC TECHNOLOGY

2019 ◽  
pp. 54-59
Author(s):  
R.S. Rakhmanov ◽  
Е.S. Bogomolova ◽  
M.V. Ashina ◽  
A.V. Tarasov ◽  
A.E. Gruzdeva ◽  
...  
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Comparison Group ◽  
Educational Institution ◽  
Hemoglobin Concentration ◽  
The Body ◽  
Relative Width ◽  
Initial State ◽  
Cryogenic Technology ◽  
Average Hemoglobin

We estimated the hemograms indices of the schoolstudents’ blood enrolled a high military educational institution. By cryogenic technology produced products from protein-vegetable (first) or vegetable raw materials (second) were introduced into the diet of the two main groups. The comparison group was the third one. The blood samples study was performed three times: in the initial state, after taking the product and after 30 days of observation. The average red blood cell volume increased in all examined patients indicating a compensatory reaction of the body to the load, the growth one was less significant in the main groups. The average hemoglobin content in the red blood cell in the first group did not change by stages of observation, in the second and third groups it was decreased by the end of observation. The average hemoglobin concentration decreased, it was less in the main groups. We noted an increase in the number of lymphocytes by 20.7 %, (p = 0.0001) and an increase in the indicator of a mixture from monocytes, basophils, eosinophils when taking the first product. An increase in the number of lymphocytes was noted in the second and third groups only by the end of the observation. The relative lymphocytes content when taking the first product was more significant in the second and third stages of observation than in the initial state; in the second one it was by the end of the observation. The relative neutrophils content in the first group decreased by the end of reception, in the second one it was by the end of observation; in the comparison group remained unchanged. The average platelets volume have been decreased in the first and control groups by the end of the observation and in the second group by the end of taking the product. The relative width of the platelets distribution by volume and the coefficient of large platelets have been decreased in individuals of the group, which may have a positive effect on blood clotting. Thus, the influence of adaptation factors in the main groups was less significant than in the comparison group.

Growth-induced compatible strains

2016 ◽  
Vol 22 (1) ◽  
pp. 62-71 ◽  
Author(s):  
Manuela Minozzi ◽  
Paola Nardinocchi ◽  
Luciano Teresi ◽  
Valerio Varano
Keyword(s):  
Stress State ◽  
Time Evolution ◽  
Linear Elasticity ◽  
Free State ◽  
Evolution Problem ◽  
Euclidean Ball ◽  
Initial State ◽  
Non Linear ◽  
Stress Free State

We studied the time evolution problem driven by growth for a non-Euclidean ball which at its initial state is equipped with a non-compatible distortion field. The problem is set within the framework of non-linear elasticity with large growing distortions. No bulk accretive forces are considered, and growth is only driven by the stress state. We showed that, when stress-driven growth is considered, distortions can evolve along different trajectories which share a common attracting manifold; moreover, they eventually attain a steady and compatible form, to which there corresponds a stress-free state of the ball.

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