Free University of Berlin

About: Free University of Berlin is a education organization based out in Berlin, Germany. It is known for research contribution in the topics: Population & Context (language use). The organization has 35195 authors who have published 66525 publications receiving 2094403 citations. The organization is also known as: FU Berlin.

Dendritic polyglycerols for biomedical applications.

Abstract: The application of nanotechnology in medicine and pharmaceuticals is a rapidly advancing field that is quickly gaining acceptance and recognition as an independent area of research called "nanomedicine". Urgent needs in this field, however, are biocompatible and bioactive materials for antifouling surfaces and nanoparticles for drug delivery. Therefore, extensive attention has been given to the design and development of new macromolecular structures. Among the various polymeric architectures, dendritic ("treelike") polymers have experienced an exponential development due to their highly branched, multifunctional, and well-defined structures. This Review describes the diverse syntheses and biomedical applications of dendritic polyglycerols (PGs). These polymers exhibit good chemical stability and inertness under biological conditions and are highly biocompatible. Oligoglycerols and their fatty acid esters are FDA-approved and are already being used in a variety of consumer applications, e.g., cosmetics and toiletries, food industries, cleaning and softening agents, pharmaceuticals, polymers and polymer additives, printing photographing materials, and electronics. Herein, we present the current status of dendritic PGs as functional dendritic architectures with particular focus on their application in nanomedicine, in drug, dye, and gene delivery, as well as in regenerative medicine in the form of non-fouling surfaces and matrix materials.

Die Wasserstoffbrücke im Festkörper

Abstract: Die Wasserstoffbrucke ist die wichtigste der gerichteten intermolekularen Wechselwirkungen. Sie spielt fur die molekulare Konformation, Aggregation und Funktion einer grosen Anzahl chemischer Systeme, die vom anorganischen bis zum biologischen Sektor reichen, wichtige Rollen. Die Forschung uber Wasserstoffbrucken stagnierte in den 1980er Jahren, wurde um 1990 aber wieder belebt und ist seither in schneller Bewegung. Die Wasserstoffbrucke wird heute als ein sehr breites Phanomen mit offenen Grenzen zu anderen Effekten begriffen. In den kondensierten Phasen gibt es dutzende Arten von haufig vorkommenden X−H⋅⋅⋅A-Wasserstoffbrucken und zusatzlich sehr viele weniger haufige Typen. Die Dissoziationsenergien uberstreichen mehr als zwei Grosenordnungen (etwa 0.2 bis 40 kcal mol−1). Innerhalb dieses Bereiches ist die Natur der Wechselwirkung nicht konstant, sondern ihre elektrostatischen, kovalenten und dispersiven Anteile variieren in ihren relativen Beitragen. Die Wasserstoffbrucke hat breite Ubergangsbereiche zur kovalenten Bindung, zur Van-der-Waals-Wechselwirkung, zur ionischen Wechselwirkung und zur Kation-π-Wechselwirkung. Wasserstoffbrucken konnen als beginnende Protonentransferreaktion aufgefasst werden, und fur starke Wasserstoffbrucken kann diese Reaktion bereits in einem fortgeschrittenen Stadium sein. In diesem Aufsatz wird versucht, einen zusammenhangenden Uberblick uber alle diese Aspekte zu geben.

Equilibration, thermalisation, and the emergence of statistical mechanics in closed quantum systems.

Abstract: We review selected advances in the theoretical understanding of complex quantum many-body systems with regard to emergent notions of quantum statistical mechanics. We cover topics such as equilibration and thermalisation in pure state statistical mechanics, the eigenstate thermalisation hypothesis, the equivalence of ensembles, non-equilibration dynamics following global and local quenches as well as ramps. We also address initial state independence, absence of thermalisation, and many-body localisation. We elucidate the role played by key concepts for these phenomena, such as Lieb-Robinson bounds, entanglement growth, typicality arguments, quantum maximum entropy principles and the generalised Gibbs ensembles, and quantum (non-)integrability. We put emphasis on rigorous approaches and present the most important results in a unified language.