Thu, 24 Jul 2008 23:01:40 BST CiteULike: Author Tannoudji http://www.citeulike.org/author/Tannoudji CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/dchen/article/2767637 <i>Physical Review Letters, Vol. 100, No. 10. (2008)</i><br /><br />We introduce a general methodology based on magnetic colloids to study the recognition kinetics of tethered biomolecules. Access to the full kinetics of the reaction is provided by an explicit measure of the time evolution of the reactant densities. Binding between a single ligand and its complementary receptor is here limited by the colloidal rotational diffusion. It occurs within a binding distance that can be extracted by a reaction-diffusion theory that properly accounts for the rotational Brownian dynamics. Our reaction geometry allows us to probe a large diversity of bioadhesive molecules and tethers, thus providing a quantitative guidance for designing more efficient reactive biomimetic surfaces, as required for diagnostic, therapeutic, and tissue engineering techniques. Measuring the Kinetics of Biomolecular Recognition with Magnetic Colloids Cohen Tannoudji E Bertrand J Baudry C Robic C Goubault M Pellissier A Johner F Thalmann Lee CM Marques J Bibette doi:10.1103/PhysRevLett.100.108301 Physical Review Letters, Vol. 100, No. 10. (2008) 2008-05-07T23:01:32-00:00 2008 Physical Review Letters 100 10 APS 2008 colloids magnetic http://www.citeulike.org/user/tapnews/article/1222301 <i>Journal of Physics B: Atomic and Molecular Physics, Vol. 17, No. 22. (1984), pp. 4577-4594.</i><br /><br />In the process of cooling and trapping neutral atoms, the authors investigate a new laser configuration, which consists of two counterpropagating laser beams with orthogonal sigma $_+$ and sigma $_-$ polarisations. They show that such a configuration looks more promising than an ordinary standing wave (where the two counterpropagating waves have the same polarisation), and they explain this result as being due to angular momentum conservation which prevents any coherent redistribution of photons between the two waves. The authors' conclusions are based on a quantitative calculation of the various parameters (potential depth, friction coefficient, diffusion coefficient) describing the mean value and the fluctuations of the radiative forces experienced, in such a laser configuration, by an atom with a J=0 ground state and a J=1 excited state. Potentialities of a new &sigma;$_+$-&sigma;$_-$ laser configuration for radiative cooling and trapping J Dalibard S Reynaud Cohen Tannoudji doi:10.1088/0022-3700/17/22/018 Journal of Physics B: Atomic and Molecular Physics, Vol. 17, No. 22. (1984), pp. 4577-4594. 2007-04-12T14:16:17-00:00 1984 Journal of Physics B: Atomic and Molecular Physics 17 22 4577 4594 no-tag