Showing papers by "Udo Seifert published in 1990"
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TL;DR: It is shown that adhering (or bound) vesicles can exhibit a large variety of different shapes and the notion of a contact angle governed by tension is found to be applicable only for a restricted subset of these shapes.
Abstract: A simple model for the adhesion of vesicles to interfaces and membranes is introduced and theoretically studied. It is shown that adhering (or bound) vesicles can exhibit a large variety of different shapes. The notion of a contact angle governed by tension is found to be applicable only for a restricted subset of these shapes. Furthermore, the vesicle undergoes a nontrivial adhesion transition from a free to a bound state. This transition is governed by the balance between the overall bending and adhesion energies, and occurs even in the absence of shape fluctuations.
467 citations
TL;DR: In this paper, shape transformations of vesicles of lecithin (DMPC) in water are induced by changing the temperature which effectively changes the volume-to-area ratio.
Abstract: Shape transformations of vesicles of lecithin (DMPC) in water are induced by changing the temperature which effectively changes the volume-to-area ratio. Three different routes are found which include i) symmetric-asymmetric re-entrant transitions from a dumbbell to a pear-shaped state, ii) the expulsion of a smaller vesicle (budding), and iii) discocyte–stomatocyte transitions. All of these shape transformations are explained within a model for the bending energy of the bilayer which assumes i) that the two monolayers do not exchange lipid molecules, and ii) that the adjacent monolayers exhibit a small difference in their thermal expansivities which is easily produced, e.g., by residual impurities.
239 citations
TL;DR: In this article, the unbinding of Gaussian polymers with bending energy and external tension parallel to the wall is studied by scaling arguments and transfer matrix methods in two spatial dimensions, and three different scaling regimes can be distinguished: (i) a stiff-rod regime, (ii) a semi-flexible regime, and (iii) a crumpled regime.
Abstract: The unbinding of Gaussian polymers with bending energy and external tension parallel to the wall is studied by scaling arguments and transfer matrix methods in two spatial dimensions. Unbinding transitions occur as the strength of the wall potential or the external tension is varied. Three different scaling regimes can be distinguished: (i) a stiff-rod regime; (ii) a semi-flexible regime; and (iii) a crumpled regime. Scaling functions are calculated numerically for the crossover behaviour.
10 citations
TL;DR: Shapes and shape transformations of vesicles are considered theoretically within the spontaneous curvature model for three cases: free vesicle, the whole phase diagram, which includes pear-shaped VMs and a line of limit shapes related to budding; for toroidal VMs, three branches of solutions with low energy are found as discussed by the authors.
Abstract: Shapes and shape transformations of vesicles are considered theoretically within the spontaneous curvature model for three cases. (i) For free vesicles, the whole phase diagram is presented which includes pear-shaped vesicles and a line of limit shapes related to budding. (ii) For toroidal vesicles, three branches of solutions with low energy are found. (iii) An extension of this model to the adhesion of vesicles is briefly discussed.
5 citations
DOI•
01 Jan 1990
TL;DR: In this paper, the unbinding of Gaussian polymers with bending energy and external tension parallel to the wall is studied by scaling arguments and transfer matrix methods in two spatial dimensions, and three different scaling regimes can be distinguished: (i) a stiff-rod regime, (ii) a semi-flexible regime, and (iii) a crumpled regime.
Abstract: The unbinding of Gaussian polymers with bending energy and external tension parallel to the wall is studied by scaling arguments and transfer matrix methods in two spatial dimensions. Unbinding transitions occur as the strength of the wall potential or the external tension is varied. Three different scaling regimes can be distinguished: (i) a stiff-rod regime; (ii) a semi-flexible regime; and (iii) a crumpled regime. Scaling functions are calculated numerically for the crossover behaviour.
1 citations