Cells interactions with interfaces

A major area still not clearly understood is the exact role of proteins adsorbed from complex mixtures in cellular interactions with such interfaces. Do cells interact with adsorbed protein layers according to how much of a particular protein is present or is the conformation or state of the protein more important ... 

The chemical and electronic properties of elements at the interfaces between very thin films and bulk substrates are important in several technological areas, particularly microelectronics, sensors, catalysis, metal protection, and solar cells. To study conditions at an interface, depth profiling by ion bombardment is inadvisable, because both composition and chemical state can be altered by interaction with energetic positive ions. The normal procedure is, therefore, to start with a clean or other well-characterized substrate and deposit the thin film on to it slowly at a chosen temperature while XPS is used to monitor the composition and chemical state by recording selected characteristic spectra. The procedure continues until no further spectral changes occur, as a function of film thickness, of time elapsed since deposition, or of changes in substrate temperature. 

The approach used in these studies follows idezus from bifurcation theory. We consider the structure of solution families with a single evolving parameter with all others held fixed. The lateral size of the element of the melt/crystal interface appears 2LS one of these parameters and, in this context, the evolution of interfacial patterns are addressed for specific sizes of this element. Our approach is to examine families of cell shapes with increasing growth rate with respect to the form of the cells and to nonlinear interactions between adjacent shape families which may affect pattern formation. 

Microbial cells transported with the stream of fluid above the surface interact with conditioning films. Immediately after attachment, microorganisms initiate production of slimy adhesive substances, predominantly exopolysaccharides (EPS) that assist the formation of microcolonies and microbial films. EPS create bridges for microbial cells to the substratum and permit negatively charged bacteria to adhere to both negatively and positively charged surfaces. EPS may also control interfacial chemistry at the mineral/biofilm interface. 

The three-dimensional structure of NPY when bound to the membrane is shown in Fig. 5.6. It comprises an a-helix for residues 16 to 36 which is very well defined, and a flexible N-terminal part of the molecule. When comparing the structure of the DPC-mi-celle bound form to the structure in free solution, it is obvious that the a-helix is much more stable. In addition, the C-terminus of the helix comprising residues 32-36, which is flexible in solution, adopts an a-helical fold, and the Tyr36 is oriented such that it interacts with the water-membrane interface. 

The toxic effect on biocatalytic activity and stability in two-phase reaction system media can be divided into two effects. The first one, called the molecular-toxicity effect, is a direct toxic effect of the solvent molecules, which are dissolved in the aqueous phase and interact with the biocatalyst, particularly with whole cells. The second one, which is created by the presence of an interface between the aqueous and the organic solvent phase, is called the phase-toxicity effect [2, 24]. 

Cellular membranes serve as (tie interface between the cell and the organism of which il is a part. It has been established that ihe movement of cells, as directed during growth and development, must involve, in some way. the plasma membranes. Il also has been observed that plasma membranes play some role in cancerous growth, where cell multiplication and migration proceed at an uncontrolled rate. Membranes are composed of lipids that interact with each uther in a watery medium to form a closed... 

---