Knowledge-based membrane

Knowledge-Based Membrane Development Prediction of Separation Behavior of Zeolite and MOF Molecular Sieve Membranes... 

ProSa potentials derive from a knowledge base of globular, soluble protein structures. If they are applied to the analysis of proteins with different characteristics (such as membrane proteins), the results may lead you astray. 

Molecular Modeling, A Tool for the Knowledge-Based Design of Polymer-Based Membrane Materials... 

Most important macroscopic transport properties (i.e., permeabilities, solubilities, constants of diffusion) of polymer-based membranes have their foundation in microscopic features (e.g., free-volume distribution, segmental dynamics, distribution of polar groups, etc.) which are not sufficiently accessible to experimental characterization. Here, the simulation of reasonably equilibrated and validated atomistic models provides great opportunities to gain a deeper insight into these microscopic features that in turn will help to develop more knowledge-based approaches in membrane development. 

Modelling methodologies are contributing significantly to the knowledge-based development of membrane materials and engineering. 

The substantial contributions of calorimetry and infrared spectroscopy to our knowledge base of SC biophysics speaks for themselves. Most notably, the pivotal role of the intercellular lipid domains in SC barrier function has been elucidated and has elevated the understanding of this complex membrane to a new level. In turn, this has allowed mechanisms of permeation and mechanisms of penetration enhancement to be examined and identified. Furthermore, the opportunity to monitor the uptake and distribution of topically administered chemicals into and within the SC offers a level of detail and quantification of the permeation process, in vivo in humans, that was unimaginable a decade ago. The variety of potential applications of these findings is considerable and will form the basis of substantial further work. 

In PEM fuel cells, fed with neat hydrogen on the anode side, water fluxes in the membrane play a crucial role for the overall water balance of the cell. For the following considerations of this problem it will be supposed that the essential ex situ membrane properties are known. Based on this knowledge the membrane performance in the fuel cell will be studied. Effects of membrane properties and externally controlled conditions will be rationalized. This kind of understanding of structure versus function provides diagnostic tools to check the suitability of membranes for... 

With such an extensive knowledge base, what is the present state of our understanding of the mechanisms of this disorder Not unexpectedly, initial studies, primarily in experimental animal models, focused on the known metabolic pathways which involve thiamine. Indeed, the classical studies of Peters in 1930 (Peters, 1969) showed lactate accumulation in the brainstem of thiamine deficient birds with normalization of this in vitro when thiamine was added to the tissue. This led to the concept of the biochemical lesion of the brain in thiamine deficiency. The enzymes which depend on thiamine are shown in Fig. 14.1. They are transketolase, pyruvate and a-ketoglutarate dehydrogenase. Transketolase is involved in the pentose phosphate pathway needed to form nucleic acids and membrane lipids, including myelin. The ketoacid dehydrogenases are key enzymes of the Krebs cycle needed for energy (ATP) synthesis and also to form acetylcholine via Acetyl CoA synthesis. Decrease in activity of this cycle would result in anaerobic metabolism and lead to lactate formation (i.e., tissue acidosis) (Fig. 14.1). 

As long as the radial extension of 1st is mudi smaller than Oa bz [0, is the std.dev. of (a)] the Lorentz factor l/b will be a reasonable proximation for (1.12), but in the general case it is invalid and we have to know the exact three-dimensional form of 1st ih reciprocal space in order to evaluate lexp. Before we evaluate the general three-dimensional expression of via Qgx, we will demonstrate an additional effect of membrane undulations on the integral (1.12). For the sake of simplicity we assume stacks consisting of only one vesicle with a deltalike distribution of inter-membrane distances. In Chaps. 2 and 3 Igx was restricted to a delta-cylinder around the hz-axis and as a consequence, all our knowledge of membrane structure was based on the projection of the vesicle-layer density onto the z-axis ... 

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