A5062884757- Photosynthetic Processes and Mechanisms
- Spectroscopy and Quantum Chemical Studies
- Photoreceptor and optogenetics research
- Photochemistry and Electron Transfer Studies
- Organic Electronics and Photovoltaics
- Polymer crystallization and properties
- Libraries and Information Services
- Laser Design and Applications
- Synthesis and properties of polymers
- Mitochondrial Function and Pathology
- Solid State Laser Technologies
- Microplastics and Plastic Pollution
- Polymer Nanocomposites and Properties
- Library Science and Information Systems
- Advanced Chemical Sensor Technologies
- Analytical Chemistry and Sensors
- Food composition and properties
- Laser-Matter Interactions and Applications
- Thermal and Kinetic Analysis
- Gold and Silver Nanoparticles Synthesis and Applications
- Spectroscopy and Laser Applications
- Data Quality and Management
- Luminescence and Fluorescent Materials
- Integrated Circuits and Semiconductor Failure Analysis
- Research Data Management Practices
Humboldt-Universität zu Berlin
2013-2019
Australian National University
2008-2009
Institut de Biologie et Technologies
2009
CEA Paris-Saclay
2009
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2009
Centre National de la Recherche Scientifique
2009
Dublin City University
2009
Technische Universität Berlin
2000-2008
Max Planck Institute of Molecular Plant Physiology
2005
Defense Systems (United States)
1981
The role of digalactosyldiacylglycerol (DGDG) for the functional competence photosystem II (PS II) has been analyzed in leaves Arabidopsis thaliana plants where lipid composition was selectively modified by genetic mutations. Measurements with a newly developed laser flash fluorometer and data evaluation within framework an extended "3-quencher" model lead to following results: (i) normalized fluorescence transients F(t)/F(0) induced actinic dark adapted are virtually same wild type (WT)...
The transients of normalized fluorescence yield induced by an actinic laser flash in dark adapted leaves Arabidopsis thaliana plants were measured with new equipment, that was developed as part this work and permits the covarage a wide time domain 8 decades from 100 ns to 10 s. raw data obtained processed analyzed within framework "3-quencher" model QA photochemical P680+• 3Car nonphotochemical quenchers. Comparative measurements hydroxylamine treated PS II membrane fragments spinach...
Gold nanocavity arrays were prepared on fluorine-doped tin oxide glass by electrochemical deposition of gold through monolayers polystyrene spheres. The impact the resulting spherical cap architecture photophysics solutions and self-assembled luminophore encapsulated within nanocavities is reported for first time. From conventional confocal fluorescence microscopy, emission intensity [Ru(bpy)(2)(Qbpy)](2+) (where bpy 2,2'-bipyridyl Qbpy 2,2':4,4'':4,4''-quarterpyridyl) fullerene (C(60)) 820...
Low-temperature absorption and CD spectra, measured simultaneously, are reported from Photosystem II (PS II) reduced with sodium dithionite. Spectra were obtained using PS core complexes before after photoaccumulation of PheoD1−, the anion primary acceptor. For plant II, PheoD1− was generated under conditions in which plastoquinone present as an (QA−) a modified species taken to be neutral doubly hydroquinone (QAH2). The bleaches observed upon formation presence QA− shifted blue compared...
The present contribution describes a new experimental setup that permits time-resolved monitoring of the rise kinetics relative fluorescence yield, Φrel(t), and simultaneously decay delayed light emission, L(t), induced by strong actinic laser flashes. results obtained excitation dark-adapted samples with train eight flashes reveal (a) in suspensions spinach thylakoids, Φrel(t) exhibits typical period four oscillation is characteristic for dependence on redox states Si water oxidizing...
This study presents the first report on delayed fluorescence (DF) emitted from spinach thylakoids, D1/D2/Cyt b ‐559 preparations and solubilized light harvesting complex II (LHCII) in ns time domain after excitation with saturating laser flashes. The use of a new commercially available multichannel plate rapid gating permitted sufficient suppression detector distortions due to strong prompt fluorescence. following results were obtained: (a) dark‐adapted DF amplitudes at 100 5 μs each flash...
The boron dipyrromethene–perylenediimide dyad has been prepared and studied for its light-harvesting properties with various steady-state time-resolved spectroscopic methods.
We report the design, construction and performance of a CCD-based spectrometer system developed to study electronic absorbance spectral changes associated with electron transfer processes in biological systems. The instrument was designed operate effectively over 180–1100 nm wavelength range. temperature sample can be controlled between 5 K above 300 K. When operating 500 1000 resolution is ∼1.7–2.4 stability better than 0.001 nm, whilst maintaining close shot-noise-limited noise minimal...
Abstract: Samples of distillers dried grains with solubles (DDGS) were obtained by the National Corn-to- Ethanol Research Center (NCERC) from about 40 dry-grind ethanol plants for four different time periods in 2007 and 2008. Laboratory values crude fat, protein, neutral detergent fiber (NDF), acid (ADF), residual starch moisture determined. scanned reflectance mode on a Perkin-Elmer Spectrum-One Fourier Transform near-infrared spectrometer (12,000 to 4,000 cm-1). On DDGS calibrations NCERC...
This report summarizes the achievements of OJS community members from Germany and Switzerland in Workshop Heidelberg University Library, February 20 21, 2020. Main goal workshop was to share knowledge challenges, conceptualize document problem solving suggestions collectively develop software around OJS. Participants worked on a variety subjects including data import/export plugins, search functionality, containerization, long-time archiving XML workflows OMP. The is continuation fruitful...
Photosynthetic water oxidation to molecular oxygen and four protons is energetically driven by the cation radical P680+ that formed as a result of light induced primary charge separation. Electron transfer from redox active tyrosine residue YZ polypeptide D1 leads rapid reduction via surprisingly complex multiphasic kinetics which comprise two components (fast slow) in ns time domain. The present study reveals untreated isolated PSII core complexes spinach normalized extent significantly...
The anionic and cationic chlorin radicals P680+ Pheo- of photosystem II (PSII) act as powerful nonphotochemical quenchers chlorophyll fluorescence. After excitation with short laser flashes the primary radical pair P680+Pheo- is formed stabilized by rapid electron transfer from to QA via a 300 ps kinetics. Accordingly, PSII reaction centers populate state P680+QA- about 1 ns after saturating pulse. subsequent reduction redox active tyrosine Y within ns-timescale removes quencher fluorescence...