scholarly journals The dependence of the chain branching degree on molecular weight: Fractal analysis

2008 ◽  
Vol 14 (3) ◽  
pp. 181-184 ◽  
Author(s):  
G.V. Kozlov ◽  
Aleksandar Burya ◽  
G.B. Shustov

The fractal analysis methodology allows the clear structural identification of both chemical and physical factors controlling a chain branching degree. The effective number of branching centers per one macromolecule m is controlled by four factors: polymer molecular weight, MW, maximal 'chemical' density of reactive centers, cch, dimension of non-screening surface of macromolecular coil, du, and its fractal dimension, D. The presented research allows the determination of the critical value, Dcr = 1.10, the lower of which branching degree is equal to zero (i.e., branching does not occur).

1979 ◽  
Author(s):  
Daniel Walz ◽  
Thomas Brown

Human prothrombin activation is unique in that, in addition to the release of fragment 1.2 (FI.2) from the NH-terminus of prothrombin by factor Xa during the generation of thrombin, an additional 13 residue polypeptide, fragment 3 (F3), is autocatalytically removed from the amino-terminus of the thrombin A chain. We have developed a rapid radioimmunoassay for human F3 which incorporates short incubation times and the use of a preprecipitated second antibody; the assay can be performed in three hours. Specificity studies in buffer systems show prothrombin and prethrombin 1 cross-reacting at a level of 0.001; purified thrombin does not cross-react. In the presence of 5% BSA, prothrombin displays considerably less cross-reactivity. No immunoreactive material to F3 antibodies could be detected in 400 μL of plasma. Serum, obtained from whole blood clotting, contained measurable quantities of F3 (40-100 ng/mL). This amount in serum represents only 5-10% of the theoretical amount available should all of the fragment be hydrolytically cleaved during the conversion of prothrombin to thrombin. This assay procedure is currently being utilized to monitor the activation of purified human prothrombin in the absence and presence of selected plasma inhibitors. (Supported in part by NIH 05384-17 and the Michigan Heart Association).


2005 ◽  
Vol 1 (1) ◽  
pp. 21-24
Author(s):  
Hamid Reza Samadi

In exploration geophysics the main and initial aim is to determine density of under-research goals which have certain density difference with the host rock. Therefore, we state a method in this paper to determine the density of bouguer plate, the so-called variogram method based on fractal geometry. This method is based on minimizing surface roughness of bouguer anomaly. The fractal dimension of surface has been used as surface roughness of bouguer anomaly. Using this method, the optimal density of Charak area insouth of Hormozgan province can be determined which is 2/7 g/cfor the under-research area. This determined density has been used to correct and investigate its results about the isostasy of the studied area and results well-coincided with the geology of the area and dug exploratory holes in the text area


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