Direct Numerical Simulation of Micro-Scale Interaction Between Ice and Biological Cells

2002 ◽  
Author(s):  
L. Mao ◽  
H. S. Udaykumar ◽  
J. O. M. Karlsson
Keyword(s):  
Salt Solution ◽  
Dendritic Growth ◽  
Aqueous Salt Solution ◽  
Temperature Fields ◽  
Extracellular Medium ◽  
Permeable Membrane ◽  
Factors Affecting ◽  
Growth Modes ◽  
A Cell ◽  
Cryo Preservation

The freezing of biological material, such as cells and tissue, duing cryopreservation involves the interaction of ice in the extracellular medium with living cells. This cell-ice interaction critically determines the success of the cryo-preservation protocol, as measured by cell survival and viability after the freeze-thaw process. This paper presents numerical simulations of the response of a cell to freezing. The phase change of the aqueous salt solution outside the cell is computed using a sharp-interface technique. The cell is modeled as a salt solution enclosed by a semi-permeable membrane. We compute the concentration and temperature fields around a single cell in the presence of extracellular ice formation. Parametric variations in the factors affecting the cell-ice interaction are performed to describe the physics of thermo-solutal transport of the interaction. Cell water loss is quantified. The external ice front is computed for both stable and unstable (cellular/dendritic) growth modes. The results show that water egress from the cell is dependent on several controlling parameters in complex ways.

Transmembrane potential in vesicles formed by catanionic surfactant mixtures in an aqueous salt solution

2020 ◽  
Vol 22 (45) ◽  
pp. 26438-26451
Author(s):  
Ksenia A. Emelyanova ◽  
Polina O. Sorina ◽  
Alexey I. Victorov
Keyword(s):  
Salt Solution ◽  
Transmembrane Potential ◽  
Aqueous Salt Solution ◽  
Simple Theory ◽  
Surfactant Mixtures ◽  
Catanionic Surfactant

Simple theory shows the effects of vesicle structure and the composition of the medium on the transmembrane potential.

Factors affecting the reliability of the McMaster technique

1986 ◽  
Vol 60 (4) ◽  
pp. 260-262 ◽  
Author(s):  
Alison Dunn ◽  
Anne Keymer
Keyword(s):  
Salt Solution ◽  
Time Interval ◽  
Dilution Ratio ◽  
Laboratory Procedure ◽  
Heligmosomoides Polygyrus ◽  
Factors Affecting ◽  
Faecal Material ◽  
Mcmaster Technique ◽  
Sample Dilution ◽  
Normal Laboratory

ABSTRACTFactors detraction from the reliability of faecal egg counts based on the McMaster technique include variation in flotation time (interval between loading chamber and counting eggs) and sample dilution (ratio of faecal material to salt solution). We recommend standardization of both these variables as normal laboratory procedure, and propose optima of a 30 minute flotation time and a sample dilution of 15 ml salt solution/ g faeces for use of the McMaster technique in the estimation of the fecundity of Heligmosomoides polygyrus (Nematoda).

scholarly journals Oxygen transport and release of adenosine triphosphate in micro-channels

2015 ◽  
Author(s):  
Terry Moschandreou
Keyword(s):  
Oxygen Transport ◽  
Rapid Change ◽  
Microfluidic Channel ◽  
Permeable Membrane ◽  
Micro Channels ◽  
Free Region ◽  
Method Of Solution ◽  
Channel Tube ◽  
A Cell ◽  
The Right

The governing nonlinear steady equations for oxygen transport in a microfluidic channel are solved analytically. The Lagrange inversion theorem is used which admits complete integrable solutions in the channel. Considering a cell-rich and cell free region with RBCs and blood plasma, we obtain results showing clearly that there is a significant decrease in oxygen tension in the vicinity of an oxygen permeable membrane placed on the upper channel/tube wall and to the right side of it in the downstream field. The purpose of the membrane is to cause a rapid change in oxygen saturation as RBC’s flow through channel/tube. To the right of the membrane downstream the greatest amount of ATP is released. The method of solution is compared to numerical results. The analytical results obtained could prove useful for the corresponding time dependent problem in future studies.

Spectrophotometry Study of Aqueous Salt Solution in Carbon Dioxide Microemulsions

Langmuir ◽  
2002 ◽  
Vol 18 (10) ◽  
pp. 3787-3791 ◽  
Author(s):  
Mohammed J. Meziani ◽  
Ya-Ping Sun
Keyword(s):  
Carbon Dioxide ◽  
Salt Solution ◽  
Aqueous Salt Solution

scholarly journals Droplet desorption modes at high heat flux

2019 ◽  
Vol 196 ◽  
pp. 00002
Author(s):  
Sergey Misyura ◽  
Anton Meleshkin
Keyword(s):  
Temperature Field ◽  
Salt Solution ◽  
Ambient Air ◽  
Nucleate Boiling ◽  
High Heat ◽  
Droplet Surface ◽  
Aqueous Salt Solution ◽  
Heated Wall ◽  
High Heat Flux ◽  
Desorption Rate

Nonisothermal droplet desorption of aqueous salt solution H2O/LiBr during nucleate boiling was studied experimentally. A droplet was placed on a horizontal heated wall. The initial concentration of salt C0 = 25 %. The wall temperature Tw = 120 °C and ambient air pressure is 1 bar. Thermal images of the temperature field on the droplet surface show an extremely non-uniform temperature field. At nucleate boiling in LiBr salt solution it is incorrect to predict the desorption behavior in stationary approximation. It was previously believed that the rate of evaporation does not vary with time. For the first time it is shown that the desorption rate is divided into several characteristic time intervals. These intervals is characterized by a significant change in the desorption rate.

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