282 research outputs found
Zweidimensionale Architekturen organischer Adsorbate: Untersuchung mittels STM, LEED, TDS und Kraftfeldsimulationen
Die vorliegende Arbeit beschreibt die experimentelle Untersuchung organischer Adsorbate mit Hilfe der Raster-Tunnel-Mikroskopie im Ultrahochvakuum (UHV) und an ambienten Bedingungen. Im Zentrum dieser Arbeit stehen Untersuchun-gen an selbstassemblierten Monolagen von Trimesinsäure. Eine vorgeschlagene Gast-Wirt-Struktur aus Trimesinsäure wurde erzeugt und mit submolekularer Auf-lösung abgebildet. Ferner ist es gelungen gezielt Gäste in die Wirtstruktur einzu-lagern und zu manipulieren. Als Gäste konnten, neben Trimesinsäure selbst, Coronen, Fullerene und Gold-Cluster gezeigt werden
Analytic calculation of the 1-loop effective action for the O(N+1)-symmetric 2-dimensional nonlinear sigma-model
Polyakov's calculation of the effective action for the 2d nonlinear
sigma-Model is generalized by purely analytic means to include contributions
which are not UV-divergent and which depend on the choice of block spin. An
analytic approximation to the background field which determines the classical
perfect action is given, and approximations to the 1-loop correction are found.
The results should be useful for numerical simulations.Comment: 38 p, 1 figur
Self-consistent Calculation of Real Space Renormalization Group Flows and Effective Potentials
We show how to compute real space renormalization group flows in lattice
field theory by a self-consistent method. In each step, the integration over
the fluctuation field (high frequency components of the field) is performed by
a saddle point method. The saddle point depends on the block-spin. Higher
powers of derivatives of the field are neglected in the actions, but no
polynomial approximation in the field is made. The flow preserves a simple
parameterization of the action. In this paper we treat scalar field theories as
an example.Comment: 52 pages, uses pstricks macro, three ps-figure
Nanopatterning of a Covalent Organic Framework Host-Guest System
We have used a boroxine-based COF as a template for C60-fullerene self-assembly on graphite. Local removal of the COF by STM based nanomanipulation creates nanocorrals that may host other species
Broken symmetry and the variation of critical properties in the phase behaviour of supramolecular rhombus tilings
The degree of randomness, or partial order, present in two-dimensional
supramolecular arrays of isophthalate tetracarboxylic acids is shown to vary
due to subtle chemical changes such as the choice of solvent or small
differences in molecular dimensions. This variation may be quantified using an
order parameter and reveals a novel phase behaviour including random tiling
with varying critical properties as well as ordered phases dominated by either
parallel or non-parallel alignment of neighbouring molecules, consistent with
long-standing theoretical studies. The balance between order and randomness is
driven by small differences in the intermolecular interaction energies, which
we show, using numerical simulations, can be related to the measured order
parameter. Significant variations occur even when the energy difference is much
less than the thermal energy highlighting the delicate balance between entropic
and energetic effects in complex self-assembly processes
Height dependent molecular trapping in stacked cyclic porphyrin nanorings
Stacked layers of cyclic porphyrin nanorings constitute nanoscale receptacles with variable height and diameter which preferentially adsorb sublimed molecules. Using scanning tunnelling microscopy we determine the filling capacity of these nanoring traps, and the dependence of adsorbate capture on stack height and diameter
Energy Efficiency of Sequence Alignment Tools - Software and Hardware Perspectives
Kierzynka M, Kosmann L, vor dem Berge M, et al. Energy Efficiency of Sequence Alignment Tools - Software and Hardware Perspectives. Future Generation Computer Systems. 2016;67:455-465
Oncogenic role of miR-155 in anaplastic large cell lymphoma lacking the t(2;5) translocation.
Anaplastic large cell lymphoma (ALCL) is a rare, aggressive, non-Hodgkin's lymphoma that is characterized by CD30 expression and disease onset in young patients. About half of ALCL patients bear the t(2;5)(p23;q35) translocation, which results in the formation of the nucleophosmin-anaplastic lymphoma tyrosine kinase (NPM-ALK) fusion protein (ALCL ALK(+)). However, little is known about the molecular features and tumour drivers in ALK-negative ALCL (ALCL ALK(-)), which is characterized by a worse prognosis. We found that ALCL ALK(-), in contrast to ALCL ALK(+), lymphomas display high miR-155 expression. Consistent with this, we observed an inverse correlation between miR-155 promoter methylation and miR-155 expression in ALCL. However, no direct effect of the ALK kinase on miR-155 levels was observed. Ago2 immunoprecipitation revealed miR-155 as the most abundant miRNA, and enrichment of target mRNAs C/EBPβ and SOCS1. To investigate its function, we over-expressed miR-155 in ALCL ALK(+) cell lines and demonstrated reduced levels of C/EBPβ and SOCS1. In murine engraftment models of ALCL ALK(-), we showed that anti-miR-155 mimics are able to reduce tumour growth. This goes hand-in-hand with increased levels of cleaved caspase-3 and high SOCS1 in these tumours, which leads to suppression of STAT3 signalling. Moreover, miR-155 induces IL-22 expression and suppresses the C/EBPβ target IL-8. These data suggest that miR-155 can act as a tumour driver in ALCL ALK(-) and blocking miR-155 could be therapeutically relevant. Original miRNA array data are to be found in the supplementary material (Table S1).This work was supported by the SCRI-LIMCR GmbH, the “Jubiläumsfond der Österreichischen Nationalbank” (grant-no. 14856 to O.M.), R.G. was supported by grant SFB P021 from the Austrian Science Funds (FWF), L.K. was supported by grant FWF, P26011, R.M. was supported by FWF grants SFB F28 and SFB F47. S.D.T. is a Senior Lecturer supported with funding from Leukemia and Lymphoma Research.This is the final version of the article. It first appeared from Wiley via http://dx.doi.org/10.1002/path.453
A Reconfigurable Heterogeneous Microserver Architecture for Energy-efficient Computing
Kaiser M, Griessl R, Hagemeyer J, et al. A Reconfigurable Heterogeneous Microserver Architecture for Energy-efficient Computing. In: Third International Workshop on Heterogeneous High-performance Reconfigurable Computing (H2RC'17). Denver, CO; 2017
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