Equation for osmotic pressure of serum protein (fractions)

2004 ◽  
Vol 96 (2) ◽  
pp. 762-764 ◽  
Author(s):  
Johan Ahlqvist
Keyword(s):  
Molecular Weight ◽  
Regression Analysis ◽  
Osmotic Pressure ◽  
Serum Protein ◽  
Protein Fractions ◽  
Fibrinogen Concentration ◽  
Nonlinear Regression Analysis ◽  
Molecular Weights ◽  
Wide Range ◽  
Better Than

The colloid or protein osmotic pressure (Π) is a function of protein molarity (linear) and of Donnan and other effects. Albumin is the major osmotic protein, but also globulins influence Π. Equations based on concentrations of albumin and nonalbumin (globulin concentration + fibrinogen concentration) protein approximate Π better than albumin alone. Globulins have a wide range of molecular weights, and a 1956 diagram indicated that Π of globulin fractions decreased in the order α1-, α2-, β-, and γ-globulin. The molecular weight of the serum protein fractions had been extrapolated, so van't Hoff's law and nonlinear regression analysis of the curves permitted expression of the diagram as an equation: [Formula: see text], where Πs,Ott,2°C,cmH2O is Π of serum at 2°C (in cmH2O) computed from the 1956 diagram, Ctot is the concentration (g/l) of total protein in serum, and xalb, xα1, xα2, xβ, and xγ are the fractions of albumin, α1-, α2-, β-, and γ-globulin, respectively. At one and the same concentration of fractions, Π“Ott” decreases in the order α1-globulin, albumin, α2-globulin, β-globulin, and γ-globulin.

scholarly journals OSMOTIC PRESSURE STUDY OF PROTEIN FRACTIONS IN NORMAL AND IN NEPHROTIC SUBJECTS

1939 ◽  
Vol 69 (6) ◽  
pp. 819-831 ◽  
Author(s):  
Jaques Bourdillon
Keyword(s):  
Osmotic Pressure ◽  
Normal Serum ◽  
The Other ◽  
Protein Fractions ◽  
Molecular Weights ◽  
Other Hand ◽  
Normal Albumin

In serum of patients with nephrosis both albumin and globulin showed by osmotic pressure nearly double the molecular weights of normal albumin and globulin. In the urines of such patients, on the other hand, both proteins showed molecular weights lower even than in normal serum. The colloidal osmotic pressures were measured by the author's method at such dilutions that the van't Hoff law relating pressures to molecular concentrations could be directly applied. For the albumin and globulin of normal serum the molecular weights found were 72,000 and 164,000 respectively, in agreement with the weights obtained by other methods.

Viscoelastic relaxation in poly-1-butenes of low molecular weight

1967 ◽  
Vol 300 (1462) ◽  
pp. 356-372 ◽  
Keyword(s):  
Molecular Weight ◽  
Steady Flow ◽  
Simple Liquid ◽  
Viscoelastic Relaxation ◽  
Low Frequencies ◽  
Chain Polymer ◽  
Molecular Weights ◽  
Wide Range ◽  
Volume Equation ◽  
Rouse Theory

Measurements have been made of the viscoelastic properties of a range of poly-1-butene liquids of different molecular weights under cyclic shearing stress. The five liquids studied range in steady-flow viscosity at 20 °C from 5.5 to 9330 P corresponding to number average molecular weights from 448 to 2700. Measurements over the temperature range – 60 to +90 °C were made at frequencies of alternating shear of 64 kc/s, 6, 18 and 30 Mc/s. The liquid of lowest molecular weight (448) was nominally pure, having eight repeat units, while the remaining four each had a distribution of molecular weights. In all cases, the dependence of steady flow viscosity upon temperature follows the equation In η = A + B /(T - T 0 ), (1) which is derived from the free-volume equation with a linear dependence of density upon temperature. Recent measurements on a wide range of pure liquids which have viscosities described by equation (1) have been interpreted in terms of a simple phenomenological model for viscoelastic relaxation which allows the behaviour to be predicted (Barlow, Erginsav & Lamb 1967 b ). Analysis of the present results on the liquid of lowest molecular weight shows that the measured behaviour can also be described by this model. For the four liquids of higher molecular weight a second relaxation process is found at lower frequencies. This is attributed to the increased chain length of the molecules giving rise to 'quasi-Rouse’ modes of motion. At low frequencies the results for these four liquids show a behaviour intermediate between that of a simple liquid and that exhibited by a long chain polymer which conforms to the extended form of the Rouse theory.

The Structure of Neoprene. I. The Molecular-Weight Distribution of Neoprene Type GN

1949 ◽  
Vol 22 (3) ◽  
pp. 680-689
Author(s):  
W. E. Mochel ◽  
J. B. Nichols ◽  
C. J. Mighton
Keyword(s):  
Molecular Weight ◽  
Natural Rubber ◽  
Osmotic Pressure ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Distribution Curve ◽  
Pressure Measurements ◽  
Dilute Solution ◽  
Molecular Weights ◽  
Good Agreement

Abstract Polychloroprene rubber (Neoprene Type GN) was fractionated by partial precipitation from dilute solution in benzene and the fractions were examined both osmotically and viscometrically in benzene solutions. The molecular-weight distribution curve for Neoprene Type GN based on osmotic pressure measurements shows a pronounced maximum at 100,000, but has a long extension to molecular weights of over one million, indicating the presence of branched or cross-linked material which is still soluble. The uniformity is somewhat less than that of sol natural rubber, while in shape the Neoprene distribution curve resembles more closely that of peptized natural rubber than fresh sol rubber. Observed variations in the slopes of the π/c vs. c and the ηsp/c vs. c curves also indicate the presence in solution of complex, branched and (or) cross-linked molecules. Calibration of the intrinsic viscosity-molecular weight relationship by osmotic pressure measurements gave good agreement with the equation: [η]=KMa, where K=1.46×10−4 and a=0.73.

Vaginal Absorption of Polyvinyl Alcohol in Fischer 344 Rats

1990 ◽  
Vol 9 (2) ◽  
pp. 71-77 ◽  
Author(s):  
J.M. Sanders ◽  
H.B. Matthews
Keyword(s):  
Molecular Weight ◽  
Polyvinyl Alcohol ◽  
Low Molecular Weight ◽  
Fischer 344 Rats ◽  
Gi Tract ◽  
Molecular Weights ◽  
Fischer 344 ◽  
Human Dose ◽  
Wide Range ◽  
Intravaginal Administration

Polyvinyl alcohol (PVA) is a polymer with a wide range of molecular weights and uses. Recently, low molecular weight formulations of PVA have been used as components of contraceptive products designed for intravaginal administration in human females. Previous studies in animals have determined that little or no absorption of PVA occurs from the gastrointestinal (GI) tract. However, there is some concern that PVA of lower molecular weights might be absorbed across membranes of the reproductive tract. Consequently, this work has investigated the absorption of low molecular weight PVA across biological membranes of the reproductive and GI tracts of Fischer 344 rats. Oral administration of ten consecutive daily doses of 14C PVA resulted in little apparent absorption of the dose from the GI tract. In contrast, intravaginal administration of 14C PVA resulted in increasing concentrations of PVA-derived radioactivity in major tissues following one, three or ten daily doses of the estimated human dose of 3 mg/kg. PVA-derived radioactivity was concentrated mainly in the liver, reaching a peak greater than 1750 ng equivalents/g tissue 24 hours following ten daily doses. Over 300 ng equivalents/g tissue were still present in the liver 30 days following the last dose.

scholarly journals The Influence of the Different Disposition Characteristics of Snake Toxins on the Pharmacokinetics of Snake Venom

Toxins ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 188 ◽  
Author(s):  
Suchaya Sanhajariya ◽  
Geoffrey K. Isbister ◽  
Stephen B. Duffull
Keyword(s):  
Molecular Weight ◽  
Snake Venom ◽  
Time Course ◽  
Total Concentration ◽  
Weight Fraction ◽  
Pharmacokinetic Parameters ◽  
Time Data ◽  
Molecular Weights ◽  
Concentration Time ◽  
Wide Range

Snake venom is comprised of a combination of different proteins and peptides with a wide range of molecular weights and different disposition processes inherent to each compound. This causes venom to have a complex exposure profile. Our study investigates 1) how each molecular weight fraction (toxin) of venom contributes to the overall time course of the snake venom, and 2) the ability to determine toxin profiles based on the profile of the overall venom only. We undertook an in silico simulation and modelling study. Sixteen variations of venom, comprising of two to nine toxins with different molecular weights were investigated. The pharmacokinetic parameters (i.e., clearance,  C L , and volume of distribution,  V ) of each toxin were generated based on a log-linear relationship with molecular weight. The concentration–time data of each toxin were simulated for 100 virtual patients using MATLAB and the total concentration–time data of each toxin were modelled using NONMEM. We found that the data of sixteen mixtures were best described by either two- or three-compartment models, despite the venom being made up of more than three different toxins. This suggests that it is generally not possible to determine individual toxin profiles based on measurements of total venom concentrations only.

Thermomechanical Characterization of the Molecular Weight of Linear Polymers Exemplified by Natural Rubber

1964 ◽  
Vol 37 (1) ◽  
pp. 99-102
Author(s):  
B. Ya Teitelbaum ◽  
K. F. Gubanov
Keyword(s):  
Molecular Weight ◽  
Experimental Studies ◽  
Thermomechanical Properties ◽  
Linear Polymers ◽  
Molecular Weights ◽  
Calculated Molecular Weight ◽  
Low Degree ◽  
Wide Range ◽  
High Elasticity

Abstract In the previous work of Kargin and Slonimskii and that of Kargin and Sogolov who studied the behavior of polymers over a wide range of temperature, it was shown that the shape of thermomechanical curves depends on magnitude of molecular weight of the polymers. As a result of investigation of theory and actual experimental studies in which polyisobutylene was employed, it was demonstrated that molecular weight could be estimated on the basis of thermomechanical properties. This suggested a relationship between the magnitude of molecular weight M found from the thermomechanical curves and that which was determined from glass temperatures Tg and fluid temperatures Tf. For practical use of this relationship, it is necessary to know the magnitude of the segments and two empirical constants. These values can be found by calculation of molecular weights of three different fractions of the polymer. This can be accomplished experimentally by any independent method. Once these magnitudes are determined, it is necessary to find, by means of the thermomechanical curve, the values Tg and Tf, in order to calculate the molecular weight of any sample of the same polymer. Because of the low degree of accuracy of determination of these values, and because of the peculiar differences, the reliability of the calculated molecular weight cannot be great, especially since the equation utilizes the logarithm of the molecular weight figure and not the molecular weight itself. Apparently the graphic solution is simpler than analytical methods: by means of the data of thermomechanical studies for various fractions of known molecular weights it is possible to graph the dependence of M or log Mon Tf−Tg. From what has been said, it is evident that we may use the demonstrated method only for polymers of high elasticity, and furthermore, only for those fractions in which Tf−Tg is greater than zero.

scholarly journals Expression of plasmolemma proteins of the absorptive enterocytes of the cattle in the late fetal period

2020 ◽  
Vol 3 (1) ◽  
pp. 52-57
Author(s):  
D. M. Masiuk
Keyword(s):  
Molecular Weight ◽  
Basolateral Membrane ◽  
Protein Fractions ◽  
Low Molecular Weight ◽  
Fetal Period ◽  
Molecular Weights ◽  
Weight Protein ◽  
Low Molecular Weight Protein ◽  
Apical Membranes ◽  
Absorptive Enterocytes

The article presents new scientific data on the expression of plasmalemma proteins of the absorptive enterocytes of the bovine intestines of five to nine months of age. In the late fetal period, 31 and 27 protein fractions of apical and basolateral membranes, respectively, were found in the plasmalemma of the jejunum intestine, which had a molecular weight of 9.6 kDa to 300 kDa. Twenty-nine protein fractions were detected in the apical membranes of five-month-old cattle enterocytes. It should be noted that protein fractions with low molecular weight (up to 24 kDa) were only 19.7 %, with molecular weights from 24 kDa to 100 kDa – 69.2 %, and fractions with molecular weights of 100 kDa and more were detected only – 11.1 % of the total number of polypeptides. Twenty-five protein fractions with a molecular weight of 9.6 to 155 kDa were found in the basolateral enterocyte membranes of five-month-old fetus. A large proportion of the detected protein fractions belonged to low molecular weight polypeptides (9.6–24 kDa – 40.26 %). Proteins with a molecular weight of 24–95 kDa – 55.2 %, with a molecular mass of 100 kDa and more were found only 4.56 %. High molecular weight proteins in the basolateral membrane of jejunum enterocytes of five-months-old cattle with a molecular weight greater than 155 kDa were not detected by electrophoresis (unlike the apical membrane). Analysis of the results of studies membranes protein of cattle enterocytes in late fetal period indicates significant changes in their polypeptide composition. In particular, in the basolateral membranes of enterocytes during the late fetal period there is a decrease in the content of low molecular weight protein fractions (3.3 times; P ≤ 0.001) and an increase in the proportion of high molecular weight. In addition, from the age of eight months, proteins with a molecular weight of 9.6–14.2 kDa and 75 kDa disappear in the basolateral membrane. Instead, proteins with a molecular weight of 300 kDa and 170-1885 kDa are appeared. In addition, in the apical membranes of enterocytes there is a significant decrease in the content of low molecular weight protein fractions and an increase in polypeptides with a molecular weight greater than 100 kDa. The appearance in the apical membranes of jejunum enterocytes of calves from eight months of age embryonic development of fractions of polypeptides with molecular weight of 24 kDa and 66 kDa, which are present until the end of the fetal period.

A variety of morphologies in diblock copolymer/homopolymer blends

1989 ◽  
Vol 47 ◽  
pp. 346-347
Author(s):  
Edwin L. Thomas ◽  
Karen I. Winey
Keyword(s):  
Molecular Weight ◽  
Block Copolymer ◽  
Diblock Copolymer ◽  
Copolymer Composition ◽  
Molecular Weights ◽  
Copolymer Concentration ◽  
Wide Range ◽  
Homopolymer Blends ◽  
Long Range Ordering ◽  
Double Diamond

A wide range of morphologies and thereby physical properties can be achieved in block copolymer/homopolymer blends by varying the copolymer composition, copolymer concentration and molecular weights. Recently we investigated micelle shape transitions in diblock copolymer with homopolymer blends at low copolymer concentration. In this paper we study the microstructure over a wider concentration range for a polystyrene-polybutadiene (PS/PB) diblock copolymer of molecular weight 20.5 × 103/20.5 × 103 blended with 17.2 × 103 molecular weight homopolystyrene (hPS).Figure 1 shows schematically a possible spectrum of microdomain structures dependent on the copolymer concentration of a lamellar PS/PB and hPS. Below the critical micelle concentration (CMC) the block copolymer is molecularly dispersed in the homopolymer exhibiting a homogeneous phase. As diblock concentration increases the minority (i.e. PB) forms spherical and/or cylindrical micelles randomly dispersed in the hPS. Further increases in diblock concentration induces long range ordering of various microdomains. In addition three biphasic regions are proposed in which two phases coexist: isotropic cylinders with ordered cylinders, ordered cylinders with ordered bicontinuous double diamond (OBDD), and OBDD with swollen lamellae.

scholarly journals A simplified electrophoretic system for determining molecular weights of proteins

1977 ◽  
Vol 165 (3) ◽  
pp. 487-495 ◽  
Author(s):  
C Manwell
Keyword(s):  
Molecular Weight ◽  
Regression Analysis ◽  
Pore Size ◽  
Linear Relationship ◽  
Body Fluids ◽  
Cube Root ◽  
Species Variation ◽  
Molecular Weights ◽  
Tissue Extracts

Electrophoresis of 31 different proteins in commercially prepared polyacrylamide gradient gels, Gradipore, yields a linear relationship between a hypothetical limiting pore size (the reciprocal of a limiting gel concentration, GL) and the cube root of the mol.wt., over the range 13 500-9000 000. A regression analysis of these data reveals that 98.6% of all variability in 1/GL is explained by the molecular weight, and this degree of accuracy compares favourably with existing methods for the determination of molecular weight by retardation of mobility in polyacrylamide. This new procedure has the additional advantages that molecular-weight standards can be obtained from readily available body fluids or tissue extracts by localizing enzymes and other proteins by standard histochemical methods, and that the same electrophoretic system can be used in determining molecular weights as is used in routine surveys of populations for individual and species variation in protein heterogeneity.

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