Adhesion initial stage

The potential of using extrinsic (fluorescent) probes for monitoring the initial stages of oxidation was explored for the photo-oxidation of a UV-cured aliphatic polyurethane-acrylate-based adhesive [68]. The two probes investigated were p-dimethylamino salicylic acid (p-DASA) and 2, 7 -difluorescein (Oregon Green... 

Relaxation studies have shown that the attachment of an ion to a surface is very fast, but the establishment of equilibrium in wel1-dispersed suspensions of colloidal particles is much slower. Adsorption of cations by hydrous oxides may approach equilibrium within a matter of minutes in some systems (39-40). However, cation and anion sorption processes often exhibit a rapid initial stage of adsorption that is followed by a much slower rate of uptake (24,41-43). Several studies of short-term isotopic exchange of phosphate ions between aqueous solutions and oxide surfaces have demonstrated that the kinetics of phosphate desorption are very slow (43-45). Numerous hypotheses have been suggested for this slow attainment of equilibrium including 1) the formation of binuclear complexes on the surface (44) 2) dynamic particle-particle interactions in which an adsorbing ion enhances contact adhesion between particles (43,45-46) 3) diffusion of ions into adsorbents (47) and 4) surface precipitation (48-50). 

Figure 4. Schematic illustration of corrosion induced paint adhesion loss. In the initial stage (A), iron is oxidized and oxygen reduced at a site of electrolyte penetration as corrosion proceeds (B and C), a rust deposit forms and the anodic and cathodic reaction sites become separated. Cathodically produced hydroxide progressively disrupts paint adhesion. Reproduced from Ref. 25, copyright 1980, American Chemical Society.

Lex-antigenic trisaccharide (a-L-Fuc(l-3)-[p-D-Gal-(l-4)-p-D-GlcNAc]) and its sialylated structure (SLex) are terminal components of a nnmber of glycoconjugates on cell surfaces [31]. SLex serves as a ligand for the endothelial leukocyte molecule-1 (E-selectin) [32], which mediates the initial stages of adhesion of leukocytes to activated endothelial cells, and pays a critical role during inflammatory responses [33]. Lex-based carbohydrates have shown promise in therapeutic investigations related to the inflammatory process. As a result, extensive efforts have been directed toward the synthesis of SLex and related molecules [34 also see Chap. 15],... 

Figure 29 shows time dependence of the adhesion force between two identical acrylic acid (AAc)-grafted PET films with a graft density of 190 fig/cm2. Apparently, very weak adhesion was obtained in the initial stage of drying, but the shear strength steeply increased after 30 min and approached... 

Filled Graft Rubber as the Disperse Phase. Rubber-modified polystyrene is generally obtained by polymerization grafting of a rubber in the presence of styrene monomer. The polymerization is carried out totally or partially in mass with the aid of shearing agitation, as patented by Amos et al. (1). The study on the initial stage of this type of polymerization was first published by Bender (5), and phase inversion similar to that discovered for the two-phase pressure-sensitive adhesives was observed. The mechanism of particle formation has also been reviewed (47). 

The metal polymer interface can be studied in a variety of ways using surface science methods. Recently, much emphasis has been placed on the understanding of the initial stages of metallization of polymers. In particular, the role of metal-organic interactions as they relate to the fundamentals of adhesion mechanisms are of interest. One experimental approach is to examine the first monolayers of metal as they are deposited on a polymer surface (1), i.e the polymer is the substrate. However, the organic polymer-metal interface may be studied in the opposite perspective, via understanding the roles of organic molecular or macromolecular structure and chemistry of the metal surface qua substrate (2). In the present paper, recent ion and electron spectroscopic studies of the... 

When platelets were mica-activated they exhibited a dramatic changes of cell shape (Fig. 2a). The most striking features of the mica-activated platelets surface morphology were the formation of two different actin-based structures, filopodia and lamellipodia, and the increase in area of platelet surface. Platelets in the initial stages of adhesion to mica produced several long filopodia with width of 180-300 nm and height of 60-90 nm extending over the substrate. As the adhesion process advanced, the filopodia expanded laterally over the... 

On the Ni-B substrate, Osaka28 noticed numerous crystals of uniform size after the initial plating period of 5 s. Contrarily, on the Ni-P surfaces only a small number of gold crystals were observed. The good adhesion and uniform deposition at the Ni-B surfaces were attributed to the density of nuclei produced at the initial stages of gold deposition. 

Raine, C. S., Cannella, B., Duijvestijn, A. M., and Cross, A. H., Homing to central nervous system vasculature by antigen-specific lymphocytes. II. Lymphocyte/endo-thelial cell adhesion during the initial stages of autoimmune demyelination, Lab. Invest., 63, 476, 1990. 

Mammalian fertilization is the result of a precisely regulated series of cellular interactions. This process can be divided into a number of component stages, including the following (i) the early events that precede egg fusion, consisting of the preliminary event of sperm capacitation, sperm penetration of the cumulus oophorus, zona pellucida adhesion, initiation and completion of acrosome reactions, penetration of the zona pellucida, egg plasma membrane contact and fusion and (ii) the late events that occur within the egg that consist of sperm nuclear decondensation followed by pronuclear consolidation and syngamy. 

A major role of the microbial lectins is to mediate the adhesion of the organisms to host cells, an initial stage of infection. This has been extensively demonstrated both in uitro, in studies with isolated cells and cell cultures, and in uiuo in experimental animals. 

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