Particulate systems, incorporating

The main disadvantage in using poly(acrylamide) systems is that they are not biodegradable and the monomers are toxic. Extensive purification is also required to remove the organic solvents, anionic surfactants, and residual monomers. Edman et al. [74] produced biodegradable poly(acryldextran) particles by incorporating dextran into the poly(acrylamide) chain. These particulate systems were metabolized and eliminated faster, both in vivo and in vitro, than poly(acrylamide) particles. 

The observation by Glaser and Brown that chitin is synthesized from UDP-2-acetamido-2-deoxy-D-glucose has been confirmed in several systems. Incorporation of labeled 2-acetamido-2-deoxy-D-glucose from its UDP derivative has been found by the use of a particulate fraction from an insect the product was assumed to be chitin, but it was not actually characterized. Similar incorporation has also been observed with particulate fractions from fungi here, the product was characterized by its hydrolysis with chitinase. In one system, the dependence of incorporation on chitodextrin and the increase of V ax in the presence of (non-radioactive) 2-acetamido-2-deoxy-D-glucose were observed, confirming the results of Glaser and Brown. ... 

The synthesis of uncoated and surface-modified silica particles via the hydrolysis of tetraethoxysilane (TEOS) in a homogeneous alcoholic solution of water and ammonia is well documented in the literature [1-7]. TEOS and other metal aUtoxides (including those of titanium and iron) can be hydrolyzed in reverse microemulsion systems for the production of gels or metal oxide particles [8-16]. Systems incorporating surfactant aggregates have also been exploited in the synthesis of a number of other ultrafine particulate materials [13,15,17-20]. 

Blakes (1922) may be the first one to suggest using a modified dimensionless group incorporating the voi-dage, 8, in a particulate system. He proposed the use of the interstitial veloeity, instead of the superficial velocity, and the redproeal of the total particle surfaee area per unit volume, instead of the particle diameter, as the charaeteristic length. The Reynolds number and friction factor proposed by Blake are... 

Mannose incorporation into the glycoprotein takes place initially on polypeptide acceptors at the level of ribosomes but the massive incorporation occurs in a cytoplasmic particulate preparation. The fact that the transfer activity is found in a particulate system was the basis for the discovery that membrane lipids play an essential role in glycoprotein synthesis. 

Burma and Chakravorty W) studying a particulate system obtained from A. vinelandii, similar to the one studied previously by Connell ei al. (cf. 63) and in reement with the latter, could demonstrate no requirement for cofactors other than those required for oxidative phosphorylation however, the activity of the preparation was lost by extracting it with NaCl, but could be restored by the addition of pH 5 enzymes from rat liver. The system was capable of incorporating 18 m/zmoles of glycine per milligram protein, 9.0 m tmoles of glutamic acid, and 1.2 of leucine (compare with Table XII). 

A kidney particulate system has been described which in the presence of a suitable acceptor is capable of incorporating radioactive NANA from CMP NANA- K), into ganglioside (Kanfer et al., 1964). Asialo-Tay-Sachs ganglioside (ceramide-glu-gal-gal NAc) but not asialoganglioside (ceramide-glu-gal-gal NAc-gai) stimulated this incorporation. Also present in the... 

To assist in the deposition of these larger droplets, nebulizer inlet systems frequently incorporate a spray chamber sited immediately after the nebulizer and before the desolvation chamber. Any liquid deposited in the spray chamber is wasted analyte solution, which can be run off to waste or recycled. A nebulizer inlet may consist of (a) only a nebulizer, (b) a nebulizer and a spray chamber, or (c) a nebulizer, a spray chamber, and a desolvation chamber. Whichever arrangement is used, the object is to transfer analyte to the plasma flame in as fine a particulate consistency as possible, with as high an efficiency as possible. 

The resistances, when incorporated into equations descriptive of cross-flow filtration, yield the general expression for the permeate flux for particulate suspensions in cross-flow-electrofiltration systems. 

Fig. 14-4 Schematic representation of the transport of P through the terrestrial system. The dominant processes indicated are (1) mechanical and chemical weathering of rocks, (2) incorporation of P into terrestrial biomass and its return to the soil system through decomposition, (3) exchange reactions between soil interstitial waters and soil particles, (4) cycling in freshwater lakes, and (5) transport through the estuaries to the oceans of both particulate and dissolved P.

In addition to the interactions discussed above, which all depend in part on the ioniz-ability, or at least polarizability, of the surface and the adsorbates, hydrophobic parts of ligands may bind to corresponding parts of surfaces. Thus, if a metal ion is complexed or irreversibly bonded to a hydrophobic molecule, the metal may be incorporated into the bulk or surface of a particle via hydrophobic interaction between the molecule and the solid phase. Such interactions may be quantitatively significant in systems with high concentrations of dissolved and particulate organic matter. 

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