The Freie Universität Berlin is a renowned research university located in Berlin and one of the most prominent universities in Germany. It is internationally known for its research in the humanities and social science, as well as in the field of natural and life science. Founded in West Berlin during the early Cold War period and born out of the increasingly Communist-controlled Humboldt University, its name refers to West Berlin's status as part of the free world, as opposed to the Soviet-occupied "unfree" areas surrounding the city.Freie Universität Berlin was one of nine German universities to win in the German Universities Excellence Initiative, a national competition for universities organized by the German federal government. Winning a distinction for five doctoral programs, three interdisciplinary research clusters and its overall institutional strategy as an "International Network University", Freie Universität Berlin is one of the most successful universities in the initiative. Wikipedia.
Klein R.,Free University of Berlin
Annual Review of Fluid Mechanics
Atmospheric flows feature length scales from 10-5 to 10 5 m and timescales from microseconds to weeks or more. For scales above several kilometers and minutes, there is a natural scale separation induced by the atmosphere's thermal stratification, together with the influences of gravity and Earth's rotation, and the fact that atmospheric-flow Mach numbers are typically small. A central aim of theoretical meteorology is to understand the associated scale-specific flow phenomena, such as internal gravity waves, baroclinic instabilities, Rossby waves, cloud formation and moist convection, (anti-)cyclonic weather patterns, hurricanes, and a variety of interacting waves in the tropics. Single-scale asymptotics yields reduced sets of equations that capture the essence of these scale-specific processes. For studies of interactions across scales, techniques of multiple-scales asymptotics have received increasing recognition in recent years. This article recounts the most prominent scales and associated scale-dependent models and summarizes recent multiple-scales developments. Copyright © 2010 by Annual Reviews. All rights reserved. Source
Dias C.L.,Free University of Berlin
Physical Review Letters
We study the stability of globular proteins as a function of temperature and pressure through NPT simulations of a coarse-grained model. We reproduce the elliptical stability of proteins and highlight a unifying microscopic mechanism for pressure and cold denaturations. The mechanism involves the solvation of nonpolar residues with a thin layer of water. These solvated states have lower volume and lower hydrogen-bond energy compared to other conformations of nonpolar solutes. Hence, these solvated states are favorable at high pressure and low temperature, and they facilitate protein unfolding under these thermodynamical conditions. © 2012 American Physical Society. Source
Free University of Berlin | Date: 2013-01-17
A laser pulse shaping method is configured for microscopically viewing and modifying an object. A temporal modulation and a two-dimensional spatial modulation of laser pulses are carried out. At least the phase of the laser pulses is modulated dependent on the location, and the modulated laser pulses are directed at the object.
Qi Z.,Free University of Berlin |
Schalley C.A.,Free University of Berlin
Accounts of Chemical Research
ConspectusSupramolecular gels are ideal candidates for soft, stimuli-responsive materials, because they combine the elastic behavior of solids with the microviscous properties of fluids. The dynamic networks of fibers in supramolecular gels are reminiscent of the cytoskeleton of a cell and provide scaffolds to implement function. When gels are made responsive to stimuli, these mechanical properties can be controlled. Gel-sol transitions also open opportunities to immobilize molecules inside the gel's cavities and to release them on demand. To establish selective responsiveness, suitable recognition sites are required influencing the properties of the fiber network depending on the presence of the stimulus. Supramolecular gels are expected to be stimuli-responsive per se, for example, to temperature, mechanical stress, or an environment that is competitive with the noncovalent interactions connecting the low-molecular weight gelators. Nevertheless, the opportunities for controlling the mechanical properties are rather limited, if one merely relies on interfering with these interactions. It would be much more promising to equip the gel with additional receptor sites that offer selectivity for a broader variety of chemical stimuli. Macrocycles often exhibit a distinct host-guest chemistry and thus are excellent candidates for this purpose. A broad variety of macrocycles differing with respect to structure, topology, solubility, or biocompatibility have been incorporated in gels and endow gels with responsiveness and function. Macrocycles can have different roles: They offer rather rigid scaffolds for the construction of structurally well-defined gelator molecules. Furthermore, their host-guest interactions can be integral to gel formation, if these interactions are required to build the gel fibers. Finally, macrocycles can also be functional groups with which gelators are equipped that would also form gels in the absence of the macrocycle. Here, the macrocycle can be used as a binding site to allow additional stimuli control. To combine different stimuli for triggering gel-sol transitions certainly expands the options for establishing stimuli responsiveness. If, for example, an agent trapped inside the gel is only liberated when two different stimuli are present simultaneously, its release can be controlled with much higher precision and selectivity compared with a gel that responds to one stimulus only.In this Account, the recent progress in the construction of functional macrocycle-containing supramolecular gels is summarized. First, recent strategies to engineer responsiveness into macrocycle-containing gels are discussed. Next, different functions are presented including applications as responsive reaction media, for controlled drug-delivery or tissue engineering, and as self-healing materials. Finally, we highlight the recent progress in designing macrocycle-containing supramolecular gel materials exhibiting complex behavior. This field is part of systems chemistry and still in its infancy but appears to be one of the most promising routes to smart responsive materials. © 2014 American Chemical Society. Source
Free University of Berlin | Date: 2014-08-26
The present invention relates to the novel compound classes of dendritic polyglycerol sulfates and sulfonates as well as to their production and use for the treatment of diseases, particularly inflammatory diseases, and to their use as selectin inhibitors and selectin indicators. The dendritic polyglycerol sulfates and sulfonates are also suitable for imaging diagnostics, particularly with respect to inflammatory diseases.