Neuer langwelliger Fluoreszenzfarbstoff zur biomolekularen Erkennung von Protein-Protein-Wechselwirkungen über den Förster-Energie-Transfer

Fluoreszenz-Bioassays dienen dem sensitiven Nachweis biomolekularer Wechselwirkungen zwischen Rezeptor und Ligand, Antikörper und Antigen oder DNA und DNA. Für den Nachweis der spezifischen Bindung von einem Protein an ein anderes eignet sich der Fluoreszenz Resonante Energie Transfer (FRET). Der Energietransfer erfolgt zwischen zwei fluoroforen Gruppen, die an das jeweilige Protein gekoppelt sind, wenn eine biomolekulare Erkennung erfolgt. Der FRET ist stark abstandsabhängig (1-10 nm) und hängt nicht wie andere homogene Nachweisverfahren (die Fluoreszenz Korrelations-spektroskopie oder die Fluoreszenz Anisotropie) vom Unterschied des Molekulargewichts ab. Das FRET-Nachweisverfahren beruht auf der Grundlage der Förster-Theorie, die einen strahlungslosen Energieübertrag eines fluoreszierenden Donor-Moleküls auf ein Akzeptor-Molekül durch Dipol-Dipol-Wechselwirkungen voraussagt, wenn beide Chromophore nur wenige Nanometer entfernt sind. Als eine weitere Bedingung für den Energieübertrag ist der optimale Überlapp zwischen dem Fluoreszenzspektrums des Donor-Farbstoffes und dem Absorptionsspektrums des Akzeptors. Der Donor wird im FRET-Nachweisverfahren zum Fluoreszieren angeregt. Abhängig von der Konzentration an akzeptormarkiertem Bindungspartner sinkt die Fluoreszenz des Donors und gleichzeitig steigt die Fluoreszenz des Akzeptors

Фотолиз гетеросистем "азид свинца - кадмий"

Масс-спектрометрическим и спектрофотометрическим методами исследованы кинетические и спектральные закономерности формирования продуктов фотолиза гетеросистем PbN[6](Ам)-Cd в зависимости от интенсивности падающего света (1·10{13}…1·10{16} см{-2}·с{-1}).Создание гетеросистем PbN[6](Ам)-Cd наряду с уменьшением скорости фотолиза и фототока в области собственного поглощения PbN[6](Ам) приводит к расширению области спектральной чувствительности азида свинца, а предварительная обработка их светом lambda=365 нм - к увеличению скорости фотолиза. В результате анализа вольтамперных характеристик, контактной фотоЭДС, контактной разности потенциалов построена диаграмма энергетических зон и предложена модель фотолиза гетеросистем PbN[6](Ам)-Cd, включающая: генерацию, рекомбинацию, перераспределение неравновесных носителей в контактном поле, формирование микрогетерогенных систем PbN[6](Ам)-Pb (продукт фотолиза) и образование азота

Memory-Constrained Algorithms for Simple Polygons

A constant-workspace algorithm has read-only access to an input array and may use only O(1) additional words of $O(\log n)$ bits, where $n$ is the size of the input. We assume that a simple $n$-gon is given by the ordered sequence of its vertices. We show that we can find a triangulation of a plane straight-line graph in $O(n^2)$ time. We also consider preprocessing a simple polygon for shortest path queries when the space constraint is relaxed to allow $s$ words of working space. After a preprocessing of $O(n^2)$ time, we are able to solve shortest path queries between any two points inside the polygon in $O(n^2/s)$ time.Comment: Preprint appeared in EuroCG 201

Current and Future Issues in BPM Research: A European Perspective from the ERCIS Meeting 2010

Business process management (BPM) is a still-emerging field in the academic discipline of Information Systems (IS). This article reflects on a workshop on current and future issues in BPM research that was conducted by seventeen IS researchers from eight European countries as part of the 2010 annual meeting of the European Research Center for Information Systems (ERCIS). The results of this workshop suggest that BPM research can meaningfully contribute to investigating a broad variety of phenomena that are of interest to IS scholars, ranging from rather technical (e.g., the implementation of software architectures) to managerial (e.g., the impact of organizational culture on process performance). It further becomes noticeable that BPM researchers can make use of several research strategies, including qualitative, quantitative, and design-oriented approaches. The article offers the participants’ outlook on the future of BPM research and combines their opinions with research results from the academic literature on BPM, with the goal of contributing to establishing BPM as a distinct field of research in the IS discipline

Shower development of particles with momenta from 15 GeV to 150 GeV in the CALICE scintillator-tungsten hadronic calorimeter

We present a study of showers initiated by electrons, pions, kaons, and protons with momenta from 15 GeV to 150 GeV in the highly granular CALICE scintillator-tungsten analogue hadronic calorimeter. The data were recorded at the CERN Super Proton Synchrotron in 2011. The analysis includes measurements of the calorimeter response to each particle type as well as measurements of the energy resolution and studies of the longitudinal and radial shower development for selected particles. The results are compared to Geant4 simulations (version 9.6.p02). In the study of the energy resolution we include previously published data with beam momenta from 1 GeV to 10 GeV recorded at the CERN Proton Synchrotron in 2010.Comment: 35 pages, 21 figures, 8 table

The Time Structure of Hadronic Showers in highly granular Calorimeters with Tungsten and Steel Absorbers

The intrinsic time structure of hadronic showers influences the timing capability and the required integration time of hadronic calorimeters in particle physics experiments, and depends on the active medium and on the absorber of the calorimeter. With the CALICE T3B experiment, a setup of 15 small plastic scintillator tiles read out with Silicon Photomultipliers, the time structure of showers is measured on a statistical basis with high spatial and temporal resolution in sampling calorimeters with tungsten and steel absorbers. The results are compared to GEANT4 (version 9.4 patch 03) simulations with different hadronic physics models. These comparisons demonstrate the importance of using high precision treatment of low-energy neutrons for tungsten absorbers, while an overall good agreement between data and simulations for all considered models is observed for steel.Comment: 24 pages including author list, 9 figures, published in JINS

Introduction of a new model for time-continuous and non-contact investigations of in-vitro thrombolysis under physiological flow conditions

<p>Abstract</p> <p>Background</p> <p>Thrombolysis is a dynamic and time-dependent process influenced by the haemodynamic conditions. Currently there is no model that allows for time-continuous, non-contact measurements under physiological flow conditions. The aim of this work was to introduce such a model.</p> <p>Methods</p> <p>The model is based on a computer-controlled pump providing variable constant or pulsatile flows in a tube system filled with blood substitute. Clots can be fixed in a custom-built clot carrier within the tube system. The pressure decline at the clot carrier is measured as a novel way to measure lysis of the clot. With different experiments the hydrodynamic properties and reliability of the model were analyzed. Finally, the lysis rate of clots generated from human platelet rich plasma (PRP) was measured during a one hour combined application of diagnostic ultrasound (2 MHz, 0.179 W/cm²) and a thrombolytic agent (rt-PA) as it is commonly used for clinical sonothrombolysis treatments.</p> <p>Results</p> <p>All hydrodynamic parameters can be adjusted and measured with high accuracy. First experiments with sonothrombolysis demonstrated the feasibility of the model despite low lysis rates.</p> <p>Conclusions</p> <p>The model allows to adjust accurately all hydrodynamic parameters affecting thrombolysis under physiological flow conditions and for non-contact, time-continuous measurements. Low lysis rates of first sonothrombolysis experiments are primarily attributable to the high stability of the used PRP-clots.</p

Overview of ASDEX Upgrade results

Recent results from the ASDEX Upgrade experimental campaigns 2001 and 2002 are presented. An improved understanding of energy and particle transport emerges in terms of a 'critical gradient' model for the temperature gradients. Coupling this to particle diffusion explains most of the observed behaviour of the density profiles, in particular, the finding that strong central heating reduces the tendency for density profile peaking. Internal transport barriers (ITBs) with electron and ion temperatures in excess of 20 keV (but not simultaneously) have been achieved. By shaping the plasma, a regime with small type II edge localized modes (ELMs) has been established. Here, the maximum power deposited on the target plates was greatly reduced at constant average power. Also, an increase of the ELM frequency by injection of shallow pellets was demonstrated. ELM free operation is possible in the quiescent H-mode regime previously found in DIII-D which has also been established on ASDEX Upgrade. Regarding stability, a regime with benign neoclassical tearing modes (NTMs) was found. During electron cyclotron current drive (ECCD) stabilization of NTMs, βN could be increased well above the usual onset level without a reappearance of the NTM. Electron cyclotron resonance heating and ECCD have also been used to control the sawtooth repetition frequency at a moderate fraction of the total heating power. The inner wall of the ASDEX Upgrade vessel has increasingly been covered with tungsten without causing detrimental effects on the plasma performance. Regarding scenario integration, a scenario with a large fraction of noninductively driven current (≥50%), but without ITB has been established. It combines improved confinement (τE/τITER98 ≈ 1.2) and stability (βN ≤ 3.5) at high Greenwald fraction (ne/nGW ≈ 0.85) in steady state and with type II ELMy edge and would offer the possibility for long pulses with high fusion power at reduced current in ITER

A Roadmap for HEP Software and Computing R&D for the 2020s

Particle physics has an ambitious and broad experimental programme for the coming decades. This programme requires large investments in detector hardware, either to build new facilities and experiments, or to upgrade existing ones. Similarly, it requires commensurate investment in the R&D of software to acquire, manage, process, and analyse the shear amounts of data to be recorded. In planning for the HL-LHC in particular, it is critical that all of the collaborating stakeholders agree on the software goals and priorities, and that the efforts complement each other. In this spirit, this white paper describes the R&D activities required to prepare for this software upgrade.Peer reviewe