Plasma heterogenization

Modelling plasma chemical systems is a complex task, because these system are far from thennodynamical equilibrium. A complete model includes the external electric circuit, the various physical volume and surface reactions, the space charges and the internal electric fields, the electron kinetics, the homogeneous chemical reactions in the plasma volume as well as the heterogeneous reactions at the walls or electrodes. These reactions are initiated primarily by the electrons. In most cases, plasma chemical reactors work with a flowing gas so that the flow conditions, laminar or turbulent, must be taken into account. As discussed before, the electron gas is not in thennodynamic equilibrium... 

In 1982 a study of the usefulness of DBBF in the production of a blood substitute was reported (99). A single modification achieved the dual goals of reduced oxygen affinity and restricted tetramer—dimer dissociation. This work was confirmed in 1987 (98). The product, called aa-hemoglobin, was formulated in Ringer s lactate. P q under physiologic conditions is 3.7 kPa (28.0 torr). Hill s parameter is 2.2, and the Bohr effect was reduced (100). Plasma retention was increased, and the product appeared to be less heterogeneous than some of the other derivatives under study. Its production was scaled up by Baxter Healthcare Corp., under contract to the U.S. Army. 

In the direct insertion technique, the sample (liquid or powder) is inserted into the plasma in a graphite, tantalum, or tungsten probe. If the sample is a liquid, the probe is raised to a location just below the bottom of the plasma, until it is dry. Then the probe is moved upward into the plasma. Emission intensities must be measured with time resolution because the signal is transient and its time dependence is element dependent, due to selective volatilization of the sample. The intensity-time behavior depends on the sample, probe material, and the shape and location of the probe. The main limitations of this technique are a time-dependent background and sample heterogeneity-limited precision. Currently, no commercial instruments using direct sample insertion are available, although both manual and h ly automated systems have been described. ... 

The von Willebrand factor (vWf) is a heterogeneous multimeric plasma glycoprotein produced by megakaryocytes and endothelial cells which is found in platelets, plasma and the subendothelium. Subendothelial vWf facilitates platelet adhesion, especially under high shear stress, by binding to glycoprotein GPIb-V-IX, a complex of four leucine-rich repeat proteins on platelets. 

Sizemore, G. W. Heath, H. Ill "Immunochemical Heterogeneity of Calcitonin in Plasma of Patients With Medullary Carcinoma of the Thyroid". J. Clin. Invest. (1975), In Press. 

Dobney AM. Mank AJG, Conneely P, Grobecker K-H, de Roster CG (2000) Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) as a tool for studying heterogeneity within polymers. Submitted for publication... 

Holzer, F., Roland, U. and Kopinke, F.-D. (2002) Combination of non-thermal plasma and heterogeneous catalysis for oxidation of volatile organic compounds Part 1. Accessibility of the intra-particle volume, Appl. Cat. B Env. 38, 163-81. 

Vepfek, S. A Theoretical Approach to Heterogeneous Reactions in Non-Isothermal Low Pressure Plasma. 56, 139-159 (1975). 

In non-neuronal cells, electron microscopy studies reveal very complex endosomal compartments composed of a highly dynamic array of heterogeneous tubulovesicular-membrane structure extending from close vicinity to the plasma membrane to the cell interior, reaching the boundaries of the Golgi apparatus. Presynaptic terminals have similar endosomal systems, albeit less extensive [73, 74]. 

The heterogeneity of Lp(a) is related to ultrastructural motifs in the molecule, strongly resembling the so-called kringles found in both plasminogen and other plasma proteins, such as proteases of the coagulation system (tissue type plasminogen activator and prothrombin) (Fig. 2). 

Considerable heterogeneity has been demonstrated with respect to average plasma Lp(a) levels in different ethnic groups. These differences cannot be entirely explained by differences in allele frequencies that exist between these groups [i.e., are not entirely due to allele-specific effects on Lp(a) concentrations] (M13, S3, S4). Interestingly, in the Sudanese population, Lp(a) levels are primarily (81%) determined by factors other than the size of the apo(a) allele, while in the Malay population, only 23% of the variation in Lp(a) levels could not be accounted for by size differences in the gene (S3). In Caucasians, it has previously been reported that 40-70% of the variance in Lp(a) levels can be... 

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