Kinetics of rouleaux formation using TV image analyzer. II. Rat erythrocytes

1983 ◽  
Vol 245 (2) ◽  
pp. H259-H264 ◽  
Author(s):  
T. Shiga ◽  
K. Imaizumi ◽  
N. Maeda ◽  
K. Kon
Keyword(s):  
Kinetic Model ◽  
Rate Constant ◽  
Three Dimensional ◽  
Erythrocyte Aggregation ◽  
Image Analyzer ◽  
One Dimensional ◽  
Specific Pathogen ◽  
Time Courses ◽  
Kinetics Of ◽  
Rouleaux Formation

With the use of a rheoscope combined with a TV image analyzer, the kinetics of specific pathogen-free rat erythrocyte aggregation was studied. Under certain conditions (gamma 7.5 s-1, hematocrit 0.36%, in own plasma, at 25 degrees C) one-dimensional aggregates (rouleaux) were formed without the development of three-dimensional aggregates, perhaps because of very low concentration of gamma-globulin. The observed phenomena could be explained by 1) the erythrocyte sedimentation and 2) the rouleaux formation. The time courses, of the biphasic change in erythrocyte count and of the increments in total area and in the area/count, were successfully simulated by a kinetic model of linear polymerization, assuming a sedimentation rate constant and an association rate constant. Further, a Poissonlike distribution of the length of rouleaux was shown, as predicted theoretically on the basis of the same kinetic model.

scholarly journals Simultaneous influences of hematocrit in the erythrocyte medium on erythrocyte aggregation and sedimentation: a kinetic study by a laser scattering technique

2010 ◽  
Vol 7 (1) ◽  
pp. 139-145
Author(s):  
Baghdad Science Journal
Keyword(s):  
Single Cells ◽  
Scattered Light ◽  
Three Dimensional ◽  
Erythrocyte Aggregation ◽  
Aggregate Formation ◽  
Laser Scattering ◽  
One Dimensional ◽  
Physiological Phenomenon ◽  
Kinetics Of ◽  
Rouleaux Formation

The erythrocyte aggregation is an important physiological phenomenon in the circulation of blood. It is a basic characteristic of normal blood that plays a major role in the cardiovascular system, especially in the microcirculation. This study explained the kinetics of single cells rouleaux formation one- dimensional aggregate and three- dimensional aggregate, during simultaneous, and the effect of hematocrit on the process of aggregation and sedimentation. The present study was done on forty one healthy subjects. Laser light is passed through a well mixed sample of blood and the forward scattered light intensities recorded continuously. The samples were prepared with different hematocrit, (10%, 15%, 20%, and 25%). Increasing the hematocrit, (10%, 15%, 20%, and 25%) had significantly decreased the rate of rouleaux formation (P< 0.005) but increase in the rate of one and three dimensional aggregate formation. On the other hand the sedimentation rate is decreased significantly (P

Kinetics of rouleaux formation using TV image analyzer. I. Human erythrocytes

1983 ◽  
Vol 245 (2) ◽  
pp. H252-H258 ◽  
Author(s):  
T. Shiga ◽  
K. Imaizumi ◽  
N. Harada ◽  
M. Sekiya
Keyword(s):  
Ph Effect ◽  
Three Dimensional ◽  
Image Analyzer ◽  
Autologous Plasma ◽  
Human Fibrinogen ◽  
Shear Rates ◽  
Lower Shear ◽  
Time Courses ◽  
The Individual ◽  
Rouleaux Formation

An apparatus for determining the velocity of erythrocyte rouleaux formation was constructed, combining an inverted microscope, a transparent cone-plate viscometer, a TV image analyzer, and a computer. At lower shear rates, the overall process is the sedimentation and the rouleaux formation followed by the development of three-dimensional aggregates. The individual erythrocyte could be observed and the process was expressed by the time courses of the changes in the count and area of particles; taking the computed increment in the area/count, the rate of rouleaux formation could be estimated. The effects of shear rates, hematocrits, plasma proteins, and pH were quantified. The rate of rouleaux formation in autologous plasma increased by (1) lowering the shear rates (1.9 less than or equal to gamma less than or equal to 15 s-1),2) increasing the hematocrit (up to 0.6%), 3) adding human fibrinogen (up to 600 mg/dl) or gamma-globulin, and 4) increasing pH. The transformation to echinocytes or to stomatocytes decreased the rate of rouleaux formation. The pH effect was explained by the increase in mean corpuscular volume at lower pH rather than by the changes in the electrostatic repulsion or in the protein binding.

Kinetics and Mechanism of Acid-Catalyzed Decomposition of 1,3-Bis(4-methylphenyl)triazene in Hexane-Organic Acid Medium

1996 ◽  
Vol 61 (3) ◽  
pp. 355-363 ◽  
Author(s):  
Miroslav Ludwig ◽  
Miriam Kabíčková
Keyword(s):  
Kinetic Model ◽  
Organic Acid ◽  
Acid Medium ◽  
Rate Constant ◽  
Fourth Order ◽  
Kinetics And Mechanism ◽  
Acid Catalyzed ◽  
Kinetics Of

The kinetics of acid-catalyzed decomposition of 1,3-bis(4-methylphenyl)triazene have been studied in mixtures of hexane and organic acid of various ratios using acetic, isovaleric, and pivalic acids as the catalysts. In all the cases, a monotonously increasing dependence of the observed rate constant upon mol fraction of the acid has been found. The results obtained are discussed with the help of the classic third- and fourth-order functions by Margules and the respective kinetic model. The main catalyzing particle appears to be the dimer of the respective acid, the reaction probably going via a complex formed by two molecules of acid and one molecule of the triazene.

scholarly journals An Empirical Rate Constant Based Model to Study Capacity Fading in Lithium Ion Batteries

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Srivatsan Ramesh ◽  
K. Venkata Ratnam ◽  
Balaji Krishnamurthy
Keyword(s):  
Rate Constant ◽  
Film Formation ◽  
Solid Electrolyte Interphase ◽  
Lithium Ion ◽  
Capacity Fading ◽  
Formation Reaction ◽  
One Dimensional ◽  
Battery Systems ◽  
Diffusion And Kinetics ◽  
Kinetics Of

A one-dimensional model based on solvent diffusion and kinetics to study the formation of the SEI (solid electrolyte interphase) layer and its impact on the capacity of a lithium ion battery is developed. The model uses the earlier work on silicon oxidation but studies the kinetic limitations of the SEI growth process. The rate constant of the SEI formation reaction at the anode is seen to play a major role in film formation. The kinetics of the reactions for capacity fading for various battery systems are studied and the rate constants are evaluated. The model is used to fit the capacity fade in different battery systems.

Lumping Kinetics of Asphaltene Hydrocracking over NiMo/γ-Al2O3

2011 ◽  
Vol 396-398 ◽  
pp. 806-810
Author(s):  
Ying Xian Zhao ◽  
Da Li ◽  
Xiao Lin
Keyword(s):  
Experimental Data ◽  
Kinetic Model ◽  
Rate Constant ◽  
Suggested Model ◽  
Reaction Paths ◽  
Kinetic Feature ◽  
Kinetics Of

Catalytic hydrocracking of asphaltene over Ni-Mo/γ-Al2O3 was conducted in a microbatch reactor at 693 K. A kinetic model with four lumps (asphaltene, liquid, gas and coke) containing five reaction paths was developed. The fitting of experimental data validated the suggested model and determined the rate constant of each individual reactions, to give the insight to the kinetic feature of asphaltene catalytic hydrocracking

Structure and Formation Kinetics of Mosi2 Composites Formed by Reactive Vapor Infiltration Process

1994 ◽  
Vol 365 ◽  
Author(s):  
W.B. Hillig ◽  
R.M. Ramakrishnan ◽  
M. Broglio ◽  
N. Patibandla
Keyword(s):  
Rate Constant ◽  
Linear Increase ◽  
Growth Rate Constant ◽  
Matrix Composites ◽  
Infiltration Process ◽  
One Dimensional ◽  
Formation Kinetics ◽  
New Process ◽  
Kinetics Of ◽  
Vapor Infiltration

ABSTRACTReactive Vapor Infiltration is a convenient new process for producing high purity MoSi2 matrix composites by reacting compacted mixed Mo + MoSi2 powders ranging from 0 to 80 wt. % MoSi2 with H2 + SiCl4 vapors at temperatures from 1000 to 1400°C. Consideration must be taken of the volumetric increase that accompanies this conversion. The kinetics of the advance of the MoSi2 growth layer and the gravimetric uptake are given as a function of temperature and the composition. The parabolic growth rate constant was independent of composition at least up to 30% MoSi2 composition, but then showed a strong, linear increase with increasing MoSi2 content. There appeared to be a levelling off of rate above 70% MoSi2. The corresponding gravimetric rate constant was relatively insensitive to the starting MoSi2 content. This behavior is at variance with a simple one-dimensional diffusive growth model. Possible reasons for this variance are offered.

Structure and function of neural networks in the retina

1988 ◽  
Vol 46 ◽  
pp. 26-27
Author(s):  
Peter Sterling
Keyword(s):  
Ganglion Cells ◽  
Three Dimensional ◽  
Structure And Function ◽  
Synaptic Connections ◽  
Visual Axis ◽  
One Dimensional ◽  
Cat Retina ◽  
Ultrathin Sections ◽  
And Function ◽  
Insight Into

The synaptic connections in cat retina that link photoreceptors to ganglion cells have been analyzed quantitatively. Our approach has been to prepare serial, ultrathin sections and photograph en montage at low magnification (˜2000X) in the electron microscope. Six series, 100-300 sections long, have been prepared over the last decade. They derive from different cats but always from the same region of retina, about one degree from the center of the visual axis. The material has been analyzed by reconstructing adjacent neurons in each array and then identifying systematically the synaptic connections between arrays. Most reconstructions were done manually by tracing the outlines of processes in successive sections onto acetate sheets aligned on a cartoonist's jig. The tracings were then digitized, stacked by computer, and printed with the hidden lines removed. The results have provided rather than the usual one-dimensional account of pathways, a three-dimensional account of circuits. From this has emerged insight into the functional architecture.

Exploring the Multidimensional Facets of Authoritarianism: Authoritarian Aggression and Social Dominance Orientation

2008 ◽  
Vol 67 (1) ◽  
pp. 51-60 ◽  
Author(s):  
Stefano Passini
Keyword(s):  
Social Dominance ◽  
Factor Model ◽  
Three Dimensional ◽  
Social Dominance Orientation ◽  
Model Fit ◽  
Regression Analyses ◽  
One Dimensional ◽  
Confirmatory Factor ◽  
The One ◽  
Better Than

The relation between authoritarianism and social dominance orientation was analyzed, with authoritarianism measured using a three-dimensional scale. The implicit multidimensional structure (authoritarian submission, conventionalism, authoritarian aggression) of Altemeyer’s (1981, 1988) conceptualization of authoritarianism is inconsistent with its one-dimensional methodological operationalization. The dimensionality of authoritarianism was investigated using confirmatory factor analysis in a sample of 713 university students. As hypothesized, the three-factor model fit the data significantly better than the one-factor model. Regression analyses revealed that only authoritarian aggression was related to social dominance orientation. That is, only intolerance of deviance was related to high social dominance, whereas submissiveness was not.

Sign in / Sign up

Export Citation Format

Share Document