A5003809213- RNA and protein synthesis mechanisms
- Cell Image Analysis Techniques
- Advanced Fluorescence Microscopy Techniques
- Molecular Junctions and Nanostructures
- DNA and Nucleic Acid Chemistry
- Luminescence and Fluorescent Materials
- Organic Light-Emitting Diodes Research
- Advanced biosensing and bioanalysis techniques
- Advanced Electron Microscopy Techniques and Applications
- RNA modifications and cancer
- Conducting polymers and applications
- Organic Electronics and Photovoltaics
- Animal Genetics and Reproduction
- RNA Research and Splicing
- Spectroscopy and Quantum Chemical Studies
- Photochemistry and Electron Transfer Studies
- Semiconductor Quantum Structures and Devices
- Force Microscopy Techniques and Applications
- Photoreceptor and optogenetics research
- Zebrafish Biomedical Research Applications
- Genetic and Clinical Aspects of Sex Determination and Chromosomal Abnormalities
- ATP Synthase and ATPases Research
- Quantum Dots Synthesis And Properties
- Strong Light-Matter Interactions
- Digital Imaging for Blood Diseases
Karlsruhe Institute of Technology
2014-2025
Karlsruhe University of Education
2017
University of Illinois Urbana-Champaign
2004-2011
Heidelberg University
2007-2010
Universität Ulm
2002-2008
KU Leuven
2007
Chemnitz University of Technology
2000-2006
Institute of Semiconductor Physics
2001-2002
Russian Academy of Sciences
2002
We present a comprehensive investigation of Raman-active modes 3,4,9,10-perylene-tetracarboxylic-dianhydride (PTCDA) thin films deposited on H-passivated Si(111) substrates. The experimental data are interpreted with density-functional tight-binding scheme used for calculating the geometry and vibrational isolated molecule. These results breathing applied to optical absorption PTCDA in solution, bands can be related quantitatively elongation most prominent Raman during highest occupied...
Automated analysis of multi-dimensional microscopy images has become an integral part modern research in life science. Most available algorithms that provide sufficient segmentation quality, however, are infeasible for a large amount data due to their high complexity. In this contribution we present fast parallelized method is especially suited the extraction stained nuclei from images, e.g., developing zebrafish embryos. The idea transform input image based on gradient and normal directions...
We have developed a hidden Markov model and optimization procedure for photon-based single-molecule FRET data, which takes into account the trace-dependent background intensities. This analysis technique reveals an unprecedented amount of detail in folding kinetics Diels–Alderase ribozyme. find multitude extended (low-FRET) compact (high-FRET) states. Five states were consistently independently identified two constructs at three Mg2+ concentrations. Structures generally tend to become more...
The unmodified maturation intermediate in the biogenesis of human mitochondrial tRNALys adopts a nonfunctional conformation, resembling an extended hairpin. Single molecule fluorescence resonance energy transfer (FRET) studies reveal additional presence small population functional cloverleaf conformation. Both conformations are dynamic equilibrium, interconverting on 100 ms time scale. post-transcriptional methylation adenosine 9 to 1-methyladenosine is crucial step mature tRNA. This single...
Fluorescence blinking of single quantum dots (QDs) under constant illumination has attracted a great deal attention from both experimentalists and theoreticians. To explain the power-law behavior in distribution ``on'' ``off'' times, several models have been proposed, which charge carrier is either ejected QD to an external trap or localized at trapping site within QD. gain insight into mechanism, we studied role shell $\mathrm{CdSe}\text{\ensuremath{-}}\mathrm{ZnS}$ core-shell QDs. For two...
Here, we report a single-molecule fluorescence resonance energy transfer (FRET) study of Diels-Alderase (DAse) ribozyme, 49-mer RNA with true catalytic properties. The DAse ribozyme was labeled Cy3 and Cy5 as FRET pair dyes to observe intramolecular folding, which is prerequisite for its recognition turnover two organic substrate molecules. efficiency histograms kinetic data were taken on large number surface-immobilized molecules function the Mg2+ concentration in buffer solution. From...
Fluorescence spectroscopy is a powerful, extremely sensitive technique for the investigation of enzyme and ribozyme mechanisms. Herein, we describe synthesis characterization water-soluble fluorescence probes studying biocatalytic Diels−Alder reactions. These consist anthracene sulfonated BODIPY fluorophores fused by conjugated phenylacetylenyl bridges. Intact efficiently quenches fluorescence, likely photoinduced electron transfer. Upon destruction aromatic system reaction, emission...
Abstract A new era in developmental biology has been ushered by recent advances the quantitative imaging of all-cell morphogenesis living organisms. Here we have developed a light-sheet fluorescence microscopy-based framework with single-cell resolution for identification and characterization subtle phenotypical changes millimeter-sized Such comparative study requires analyses entire ensembles to be able distinguish sample-to-sample variations from definitive changes. We present kinetic...
Just add sugar: the synthesis of single-enzyme nanogels, a class highly robust nanobiocatalysts, is boosted by addition carbohydrates. Our methodology demonstrated with dozen commercial proteins, spanning large size interval and broad domain applications. In addition, new in-depth structural characterizations are provided.
In this paper we investigate the time-resolved and stationary photoluminescence (PL) of silicon nanocrystals fabricated in a oxide matrix. The PL intensity reveals nonexponential decay for all temperatures which can be fitted by ``stretch''-exponential function. From 60 down to 5 K an increase time is observed going along with decrease intensity. addition spectra show shape change during decay. experimental data are interpreted model self-trapped excitons (STE) localized Si-Si dimer. A...
We have characterized the biocompatibility of glass surfaces that were modified by protein layers or linear poly(ethylene glycol) (PEG) brushes with aim determining optimal treatment for immobilization single biomolecules specific attachment, which was done here using a streptavidin−biotin linkage. investigated surface homogeneity atomic force microscopy and resistance to nonspecific binding single-molecule detection fluorescently labeled RNase H in scanning confocal fluorescence microscope....
Green-to-red photoconvertible fluorescent proteins (pcFPs) are powerful tools for super-resolution localization microscopy and protein tagging. Recently, they have been found to undergo efficient photoconversion not only by the traditional 400-nm illumination but also an alternative method termed primed conversion, employing dual wavelength with blue far-red/near-infrared light. Primed conversion has reported Dendra2 its mechanism remained elusive. Here, we uncover molecular of reporting...
Cranial neural crest (NC) contributes to the developing vertebrate eye. By multidimensional, quantitative imaging, we traced origin of ocular NC cells two distinct populations that differ in maintenance sox10 expression, Wnt signalling, origin, route, mode and destination migration. The first population migrates proximal second cell group populates distal (anterior) part analysing zebrafish pax6a/b compound mutants presenting anterior segment dysgenesis, demonstrate Pax6a/b guide...
Fluorescence microscopy images are inevitably contaminated by background intensity contributions. from out-of-focus planes and scattered light important sources of slowly varying, low spatial frequency background, whereas varying pixel to (high noise) is introduced the detection system. Here we present a powerful, easy-to-use software, wavelet-based noise subtraction (WBNS), which effectively removes both these components. To assess its performance, apply WBNS synthetic compare results...
WNT signaling governs development, homeostasis, and aging of cells tissues, is frequently dysregulated in pathophysiological processes such as cancer. proteins are hydrophobic traverse the intercellular space between secreting receiving on various carriers, including extracellular vesicles (EVs). Here, we address relevance different EV fractions other vehicles for WNT5a protein, a non‐canonical ligand that signals independently beta‐catenin. Its highly context‐dependent roles cancer (either...
Time-dependent density functional theory (TD-DFT), Hartree-Fock, second-order M\o{}ller-Plesset perturbation (MP2), and configuration interaction of singly excited states (CIS) are applied to crystalline PTCDA (3,4,9,10-perylene tetracarboxylic dianhydride). The systems investigated include single molecules in an optimized rectangular shape, molecular dimers compatible with the experimental geometry $\ensuremath{\alpha}$-phase. Total energy calculations for pairs adjacent result a...
In the present work, we analyze radiative and nonradiative recombination channels in $\ensuremath{\alpha}$-PTCDA (3,4,9,10-perylene tetracarboxylic dianhydride) by applying time-resolved photoluminescence (PL) techniques 50 ns range between temperatures of $T=10\mathrm{K}$ $T=300\mathrm{K}.$ The obtained PL spectra are decomposed into exponentially decaying components which can be assigned to different types excitons, including Frenkel three self-trapped two high-energy satellites. From...
State-of-the-art light-sheet and confocal microscopes allow recording of entire embryos in 3D over time (3D+t) for many hours. Fluorescently labeled structures can be segmented tracked automatically these terabyte-scale 3D+t images, resulting thousands cell migration trajectories that provide detailed insights to large-scale tissue reorganization at the cellular level. Here we present EmbryoMiner, a new interactive open-source framework suitable in-depth analyses comparisons embryos,...
Stimulated emission depletion (STED) microscopy is a powerful super-resolution imaging technique for investigating the subcellular structure of biological samples in all three spatial dimensions. Its application to thick specimens challenging, however, as sample-induced optical aberrations distort intricate phase patterns STED beams and, consequently, their focal intensity distribution. Notably, central minimum, which essential resolution enhancement, lifted at larger sample depths. Here we...
The geometrical structure of potassium-doped Alq3 [tris-(8-hydroxyquinoline) aluminum] and the interaction between molecule potassium were studied using infrared reflection absorption spectroscopy (IRRAS), surface-enhanced Raman scattering (SERS), density functional theory calculations. A major aim this study was to examine theoretically predicted isomerization molecules from meridional form facial upon alkali-metal doping. observed spectra show significant changes with deposition on a thin...
With or without Me: The effect of a single methyl group on the free energies functional and nonfunctional conformations human mitochondrial lysine transfer RNA (tRNALys) has been studied. stabilization three distinct by Mg2+ ion binding energy changes resulting from methylation were characterized revealed preference for functionally relevant cloverleaf-shaped tRNA form (see picture). Supporting information this article is available WWW under...