Diffusion coefficient for reptation of polymers with kinematic disorder

We give a lower bound on the diffusion coefficient of a polymer chain in an entanglement network with kinematic disorder, which is obtained from an exact calculation in a modified Rubinstein-Duke lattice gas model with periodic boundary conditions. In the limit of infinite chain length we show the diffusive motion of the polymer to be slowed down by kinematic disorder by the same factor as for a single particle in a random barrier model.Comment: 8 pages, 2 figures, revised text, journal ref. adde

Stochastic many-particle systems far from equilibrium coupled to bulk reservoirs

In this work the influence of bulk reservoirs on lattice models for many-particle systems far from equilibrium is studied. A hydrodynamic equation is presented that allows to compute the steady state density profile for single species driven diffusive systems with open boundaries and a coupling of the bulk reservoir scaling with the inverse system size. Furthermore, a related model for a limit order market as well as the case of periodic single species driven models with a weak coupling to the reservoir are treated. New results on driven systems with two particle species are presented both for the cases with and without coupling to a bulk reservoir. For a two species model with periodic boundaries and conserving dynamics a novel type of phase transition is observed that is formally similar to Bose-Einstein condensation. In absence of a bulk reservoir, the existence of a spontaneously symmetry broken phase in a two species model with open boundaries and deterministic bulk behavior is demonstrated by regarding the dynamics of the system. For a related model with non-conserving bulk dynamics a rich phase diagram is found. In systems with an absorbing phase transition the action of the reservoir is that of an external field. For the universality class of directed percolation the scaling functions are determined in several dimensions.Stochastische Vielteilchen-Systeme fern des Gleichgewichtes mit platzweiser Kopplung an ein Teilchenreservoir Gegenstand der vorliegenden Arbeit ist das Studium des Einflusses von Teilchenreservoirs, die unabhängig an jeden Platz von Vielteilchen-Gittermodellen fern des Gleichgewichtes koppeln. Für eindimensionale getrieben diffusive Systeme mit einer Teilchensorte wird für den Fall einer Skalierung der Kopplungsstärke mit der inversen Systemgröße eine hydrodynamische Gleichung zur Berechnung des stationären Dichteprofiles eines Systems mit offenen Rändern eingeführt. Ferner werden ein verwandtes Modell für einen Limit-Order-Markt sowie getrieben diffusive Systeme mit einer Teilchensorte und periodischen Randbedingungen bei schwacher Kopplung an ein Reservoir betrachtet. Getrieben diffusive Systeme mit zwei Teilchensorten werden sowohl mit als auch ohne Teilchenzahlerhaltung im Inneren des Systems behandelt. Für ein periodisches System mit zwei erhaltenen Teilchensorten wird eine neue Art von Phasenübergang demonstriert, die mathematisch analog zur Bose-Einstein Kondensation ist. In einem offenen System mit zwei erhaltenen Teilchensorten wird durch Betrachtung der Dynamik die Existenz einer Phase mit spontan gebrochener Symmetrie nachgewiesen. Ein ähnliches Modell ohne Teilchenzahlerhaltung zeigt ein reichhaltiges Phasendiagramm. Für Systeme mit einem absorbierenden Phasenübergang wirkt die platzweise Kopplung an ein Teilchreservoir wie ein externes Feld.Für die Universalitätsklasse der gerichteten Perkolation werden die Skalenfunktionen um den kritischen Punkt in verschiedenen Dimensionen bestimmt

Rigorous results on spontaneous symmetry breaking in a one-dimensional driven particle system

We study spontaneous symmetry breaking in a one-dimensional driven two-species stochastic cellular automaton with parallel sublattice update and open boundaries. The dynamics are symmetric with respect to interchange of particles. Starting from an empty initial lattice, the system enters a symmetry broken state after some time T_1 through an amplification loop of initial fluctuations. It remains in the symmetry broken state for a time T_2 through a traffic jam effect. Applying a simple martingale argument, we obtain rigorous asymptotic estimates for the expected times ~ L ln(L) and ln() ~ L, where L is the system size. The actual value of T_1 depends strongly on the initial fluctuation in the amplification loop. Numerical simulations suggest that T_2 is exponentially distributed with a mean that grows exponentially in system size. For the phase transition line we argue and confirm by simulations that the flipping time between sign changes of the difference of particle numbers approaches an algebraic distribution as the system size tends to infinity.Comment: 23 pages, 7 figure

Assisting age related capabilities by ambient technology to prevent functional decline

The elderly is characterized by age related capabilities and handicaps. Whereas age related capabilities like plasticity and adaptability on changing living conditions can lead to subjective well-being and support the recovery of limiting conditions like disease and disability, age related handicaps can enforce these conditions. Multimorbidity can lead to acute and chronic functional decline, especially when limiting conditions are enforced by age related handicaps. In a "circulus vitiosus" disease and disability threaten the independence of the elderly that leads to immobility, social isolation, depression and other health conditions with amplification and generation of new diseases. Ambient Technology has the potential to interrupt this "circulus vitiosus" by limiting age related handicaps, assist age related capabilities, prevent acute or chronic diseases and as a consequence can improve the quality of life of elderly and their care giving relatives. In this overview we demonstrate a brief summary of past experience with Information and Communication Technology (ICT) as part of Ambient Technology (AT) in the "TeleReha" project and ongoing approaches in the "Vitanet" project and the "FOG-1" project followed by a future considerations conducting ICT-Project in elderly

Diffusion in a generalized Rubinstein-Duke model of electrophoresis with kinematic disorder

Using a generalized Rubinstein-Duke model we prove rigorously that kinematic disorder leaves the prediction of standard reptation theory for the scaling of the diffusion constant in the limit for long polymer chains $D \propto L^{-2}$ unaffected. Based on an analytical calculation as well as Monte Carlo simulations we predict kinematic disorder to affect the center of mass diffusion constant of an entangled polymer in the limit for long chains by the same factor as single particle diffusion in a random barrier model.Comment: 29 pages, 3 figures, submitted to PR

Moxifloxacin in Pediatric Patients With Complicated Intra-abdominal Infections: Results of the MOXIPEDIA Randomized Controlled Study

Background: This study was designed to evaluate primarily the safety and also the efficacy of moxifloxacin (MXF) in children with complicated intraabdominal infections (cIAIs). Methods: In this multicenter, randomized, double-blind, controlled study, 451 pediatric patients aged 3 months to 17 years with cIAIs were treated with intravenous/oral MXF (N = 301) or comparator (COMP, intravenous ertapenem followed by oral amoxicillin/clavulanate; N = 150) for 5 to 14 days. Doses of MXF were selected based on the results of a Phase 1 study in pediatric patients (NCT01049022). The primary endpoint was safety, with particular focus on cardiac and musculoskeletal safety; clinical and bacteriologic efficacy at test of cure was also investigated. Results: The proportion of patients with adverse events (AEs) was comparable between the 2 treatment arms (MXF: 58.1% and COMP: 54.7%). The incidence of drug-related AEs was higher in the MXF arm than in the COMP arm (14.3% and 6.7%, respectively). No cases of QTc interval prolongation-related morbidity or mortality were observed. The proportion of patients with musculoskeletal AEs was comparable between treatment arms; no drug-related events were reported. Clinical cure rates were 84.6% and 95.5% in the MXF and COMP arms, respectively, in patients with confirmed pathogen(s) at baseline. Conclusions: MXF treatment was well tolerated in children with cIAIs. However, a lower clinical cure rate was observed with MXF treatment compared with COMP. This study does not support a recommendation of MXF for children with cIAIs when alternative more efficacious antibiotics with better safety profile are available

Evaluation of integrin αvβ6 cystine knot PET tracers to detect cancer and idiopathic pulmonary fibrosis.

Advances in precision molecular imaging promise to transform our ability to detect, diagnose and treat disease. Here, we describe the engineering and validation of a new cystine knot peptide (knottin) that selectively recognizes human integrin αvβ6 with single-digit nanomolar affinity. We solve its 3D structure by NMR and x-ray crystallography and validate leads with 3 different radiolabels in pre-clinical models of cancer. We evaluate the lead tracer's safety, biodistribution and pharmacokinetics in healthy human volunteers, and show its ability to detect multiple cancers (pancreatic, cervical and lung) in patients at two study locations. Additionally, we demonstrate that the knottin PET tracers can also detect fibrotic lung disease in idiopathic pulmonary fibrosis patients. Our results indicate that these cystine knot PET tracers may have potential utility in multiple disease states that are associated with upregulation of integrin αvβ6

How to perform Contrast-Enhanced Ultrasound (CEUS)

"How to perform contrast-enhanced ultrasound (CEUS)" provides general advice on the use of ultrasound contrast agents (UCAs) for clinical decision-making and reviews technical parameters for optimal CEUS performance. CEUS techniques vary between centers, therefore, experts from EFSUMB, WFUMB and from the CEUS LI-RADS working group created a discussion forum to standardize the CEUS examination technique according to published evidence and best personal experience. The goal is to standardise the use and administration of UCAs to facilitate correct diagnoses and ultimately to improve the management and outcomes of patients