Viscosity of normal human blood under normothermic and hypothermic conditions

1964 ◽  
Vol 19 (1) ◽  
pp. 117-122 ◽  
Author(s):  
Peter W. Rand ◽  
Eleanor Lacombe ◽  
Hamilton E. Hunt ◽  
William H. Austin
Keyword(s):  
Blood Flow ◽  
Shear Rate ◽  
Heart Surgery ◽  
Blood Rheology ◽  
Normal Subjects ◽  
Future Studies ◽  
Flow Impedance ◽  
Normal Human ◽  
Technical Details ◽  
Normal Human Blood

Although blood viscosity varies in relation to shear rate, hematocrit, and temperature, equipment is now available with which it may be measured in respect to each of these variables. A simple, clinically practical technique for such measurement is presented. Blood from 60 normal subjects was adjusted to hematocrits 0, 20, 40, 60, and 80, and the viscosity-shear rate relationships measured at 37.0, 32.0, 27.0, and 22.0 C. The data obtained are presented as a reference for future studies using this method. Technical details are discussed and some deserving areas of application are considered. shear rate; cone-plate viscometer; hematocrit-viscosity relationships; blood, plasma; hematocrit; temperature; blood flow impedance; perfusion; shock; oliguria; dyspnea; coma; heart surgery; blood rheology; metabolism Submitted on May 31, 1963

Effects of chlorothiazide on forearm vascular responses to norepinephrine

1961 ◽  
Vol 16 (3) ◽  
pp. 549-552 ◽  
Author(s):  
Khalil A. Feisal ◽  
John W. Eckstein ◽  
A. W. Horsley ◽  
Hugh H. Keasling
Keyword(s):  
Blood Flow ◽  
Forearm Blood Flow ◽  
Pressor Response ◽  
Human Subjects ◽  
Chronic Administration ◽  
Normal Subjects ◽  
Vascular Responses ◽  
Chronotropic Response ◽  
Vasoconstrictor Effect ◽  
Normal Human

The effects of graded doses of norepinephrine on pulse rate, mean blood pressure, forearm blood flow and vascular resistance were studied in normal human subjects before, during, and after chronic administration of chlorothiazide. This drug prevented the negative chronotropic response normally induced by norepinephrine without altering the pressor response. Before giving and after discontinuing chlorothiazide, increasing doses of norepinephrine were associated with progressive decreases in blood flow. After 1 week of chlorothiazide administration, increasing doses of norepinephrine were associated with increases in flow. The results indicate that chlorothiazide decreases the responsiveness of the forearm vessels of normal subjects to the vasoconstrictor effect of norepinephrine. They suggest that chlorothiazide also may modify the effect of norepinephrine on cardiac output. Submitted on December 9, 1960

scholarly journals Newtonian and Non-Newtonian Blood Rheology Inside a Model of Stenosis

CFD letters ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 27-36
Author(s):  
Mohammed Ghalib Al-Azawy ◽  
Saleem Khalefa Kadhim ◽  
Azzam Sabah Hameed
Keyword(s):  
Blood Flow ◽  
Shear Rate ◽  
Three Dimensional ◽  
Blood Rheology ◽  
Carreau Model ◽  
Newtonian Model ◽  
Importance Factor ◽  
Key Issues ◽  
Computational Fluid Dynamics Cfd ◽  
Artery Disease

In order to imitate the atherosclerosis artery disease and determine the key issues, Computational Fluid Dynamics (CFD) is able to play a leading rule in the analysis of flow physics within the clogged arteries, in particular the stenosis artery. The problem of blood flow blockage through the blood vessel has been investigated numerically within a stenosis artery. In this work, a CFD technique was employed to solve the three-dimensional, steady, laminar and non-Newtonian Carreau model blood flow through a stenosis artery using Star-CCM+ software. The shape of stenosis that has been selected is a trapezoidal with two cases (70% and 90% blockage). Shear rate, streamlines, vorticity and importance factor are examined to assess the influence of non-Newtonian model through the test section, the Carreau model was compared with Newtonian model. The clinical significance of the shear rate is reported for the examined cases, observing that the levels of non-Newtonian model are predicted to be higher in the 90% blockage than that observed within the 70%; the same finding as related with the axial velocity and vorticity. The levels of re-circulation areas and vorticity are showed to be enlarged in the Carreau model compared with the case of Newtonian.

IMMUNOLOGICAL REACTIVITY OF INSULIN IN HUMAN SERUM

1966 ◽  
Vol 53 (4) ◽  
pp. 673-680 ◽  
Author(s):  
Torsten Deckert ◽  
Kai R. Jorgensen
Keyword(s):  
Normal Subjects ◽  
The Other ◽  
Human Pancreas ◽  
Porcine Pancreas ◽  
Crystalline Insulin ◽  
Endogenous Insulin ◽  
Significant Difference ◽  
Human Sera ◽  
Normal Human ◽  
The One

ABSTRACT The purpose of this study was to investigate whether a difference could be demonstrated between crystalline insulin extracted from normal human pancreas, and crystalline insulin extracted from bovine and porcine pancreas. Using Hales & Randle's (1963) immunoassay no immunological differences could be demonstrated between human and pig insulin. On the other hand, a significant difference was found, between pig and ox insulin. An attempt was also made to determine whether an immunological difference could be demonstrated between crystalline pig insulin and crystalline human insulin from non diabetic subjects on the one hand and endogenous, circulating insulin from normal subjects, obese subjects and diabetic subjects on the other. No such difference was found. From these experiments it is concluded that endogenous insulin in normal, obese and diabetic human sera is immunologically identical with human, crystalline insulin from non diabetic subjects and crystalline pig insulin.

Synthesis and solvatochromic studies of 2- amino-3-phenolazo1-(4-sulfophenyl)-3-methyi-5-pyrozolone and use it for the determination of trace amount of Nickel (II) in blood samples

2016 ◽  
Vol 5 (10) ◽  
pp. 4920
Author(s):  
Amar M. Ali ◽  
Hussain. J. Mohammed*
Keyword(s):  
Stability Constant ◽  
Trace Amount ◽  
Benzenesulfonic Acid ◽  
Determination Method ◽  
Blood Samples ◽  
Determination Of Nickel ◽  
Normal Human ◽  
The Stability ◽  
Normal Human Blood

A new, simple, sensitive and rapid spectrophotometric method is proposed for the determination of trace amount of Nickel (II). The method is based on the formation of a 1:2 complex with 4-(4-((2-hydroxy-6-nitrophenyl) diazenyl) -3-methyl-5-oxo-2, 5-dihydro-1H-pyrazol-1-yl) benzenesulfonic acid (2-ANASP) as a new reagent is developed. The complex has a maximum absorption at 516 nm and εmax of 1. 84 X 105 L. mol-1. cm-1. A linear correlation (0. 25 – 4. 0μg. ml-1) was found between absorbance at λmax and concentration. The accuracy and reproducibility of the determination method for various known amounts of Nickel (II) were tested. The results obtained are both precise (RSD was 1. 2 %) and accurate (relative error was 0. 787 %). The effect of diverse ions on the determination of Nickel (II) to investigate the selectivity of the method were also studied. The stability constant of the product was 0. 399 X 106 L. mol-1. The proposed method was successfully applied to the analysis of diabetes blood and normal human blood. 

scholarly journals Mathematical Models for Some Aspects of Blood Microcirculation

Symmetry ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1020
Author(s):  
Angiolo Farina ◽  
Antonio Fasano ◽  
Fabio Rosso
Keyword(s):  
Blood Flow ◽  
Mathematical Models ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Blood Rheology ◽  
Small Class ◽  
Small Vessels ◽  
Blood Microcirculation ◽  
Peculiar Behavior

Blood rheology is a challenging subject owing to the fact that blood is a mixture of a fluid (plasma) and of cells, among which red blood cells make about 50% of the total volume. It is precisely this circumstance that originates the peculiar behavior of blood flow in small vessels (i.e., roughly speaking, vessel with a diameter less than half a millimeter). In this class we find arteriolas, venules, and capillaries. The phenomena taking place in microcirculation are very important in supporting life. Everybody knows the importance of blood filtration in kidneys, but other phenomena, of not less importance, are known only to a small class of physicians. Overviewing such subjects reveals the fascinating complexity of microcirculation.

scholarly journals Oxygen equilibrium curve of normal human blood and its evaluation by Adair's equation.

1977 ◽  
Vol 252 (7) ◽  
pp. 2331-2337 ◽  
Author(s):  
R M Winslow ◽  
M L Swenberg ◽  
R L Berger ◽  
R I Shrager ◽  
M Luzzana ◽  
...  
Keyword(s):  
Human Blood ◽  
Equilibrium Curve ◽  
Oxygen Equilibrium ◽  
Normal Human ◽  
Oxygen Equilibrium Curve ◽  
Normal Human Blood

scholarly journals A pilot study investigating the use of 4D flow MRI for the assessment of splanchnic flow in patients suspected of mesenteric ischaemia

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pauline Hall Barrientos ◽  
Katrina Knight ◽  
Douglas Black ◽  
Alexander Vesey ◽  
Giles Roditi
Keyword(s):  
Blood Flow ◽  
Pilot Study ◽  
Splenic Vein ◽  
Normal Subjects ◽  
Mesenteric Ischaemia ◽  
4D Flow Mri ◽  
4D Flow ◽  
Flow Mri ◽  
Mesenteric Vessels ◽  
Flow Changes

AbstractThe most common cause of chronic mesenteric ischaemia is atherosclerosis which results in limitation of blood flow to the gastrointestinal tract. This pilot study aimed to evaluate 4D flow MRI as a potential tool for the analysis of blood flow changes post-prandial within the mesenteric vessels. The mesenteric vessels of twelve people were scanned; patients and healthy volunteers. A baseline MRI scan was performed after 6 h of fasting followed by a post-meal scan. Two 4D flow datasets were acquired, over the superior mesenteric artery (SMA) and the main portal venous vessels. Standard 2D time-resolved PC-MRI slices were also obtained across the aorta above the coeliac trunk, superior mesenteric vein, splenic vein and portal vein (PV). In the volunteer cohort there was a marked increase in blood flow post-meal within the PV (p = 0.028), not seen in the patient cohort (p = 0.116). Similarly, there were significant flow changes within the SMA of volunteers (p = 0.028) but not for the patient group (p = 0.116). Our pilot data has shown that there is a significant haemodynamic response to meal challenge in the PV and SMA in normal subjects compared to clinically apparent CMI patients. Therefore, the interrogation of mesenteric venous vessels exclusively is a feasible method to measure post-prandial flow changes in CMI patients.

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