A5078606215- Photosynthetic Processes and Mechanisms
- Spectroscopy and Quantum Chemical Studies
- Photoreceptor and optogenetics research
- Advanced Photocatalysis Techniques
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Polyamine Metabolism and Applications
- Light effects on plants
- Hemoglobin structure and function
- Plant Stress Responses and Tolerance
- Electron Spin Resonance Studies
- TiO2 Photocatalysis and Solar Cells
- Metal-Catalyzed Oxygenation Mechanisms
- Heme Oxygenase-1 and Carbon Monoxide
- Perovskite Materials and Applications
- Mitochondrial Function and Pathology
- Magnetism in coordination complexes
- Algal biology and biofuel production
- Electrochemical Analysis and Applications
- Neonatal Health and Biochemistry
- Plant tissue culture and regeneration
- Lanthanide and Transition Metal Complexes
- Porphyrin and Phthalocyanine Chemistry
- Photochemistry and Electron Transfer Studies
- Privacy, Security, and Data Protection
National Centre of Scientific Research "Demokritos"
2015-2025
University of Crete
2008-2024
New Jersey Institute of Technology
2020
Institute of Criminology
2020
Cyprus University of Technology
2016
Institute of Nuclear and Particle Physics
2001-2012
Washington State University
2012
Center for Research in Agricultural Genomics
2012
Intracom Telecom (Greece)
2007
University of Thessaly
2003
We have demonstrated heterogeneous photocatalytic degradation of microcystin-LR (MC-LR) by visible light activated carbon doped TiO(2) (C-TiO(2)) nanoparticles, synthesized a modified sol-gel route based on the self-assembly technique exploiting oleic acid as pore directing agent and source. The C-TiO(2) nanoparticles crystallize in anatase phase despite low calcination temperature 350 °C exhibit highly porous structure that can be optimized tuning concentration surfactant. nanomaterials...
Respiration of <i>Escherichia coli</i>catalyzed either by cytochrome <i>bo</i>′ or <i>bd</i> is sensitive to micromolar extracellular NO; extensive, transient inhibition respiration increases as dissolved oxygen tension in the medium decreases. At low concentrations (25–33 μm), duration 9 μm NO increased mutation oxidase. an <i>hmp</i> mutant defective flavohemoglobin (Hmp) synthesis extremely NO-sensitive (I<sub>50</sub> about 0.8 μm); conversely, cells pre-grown with sodium nitroprusside...
The light reactions of photosynthesis store energy in the form an electrochemical gradient protons, or proton motive force (pmf), comprised electrical (Δψ) and osmotic (ΔpH) components. Both components can drive synthesis ATP at chloroplast synthase, but ΔpH component also plays a key role regulating photosynthesis, down-regulating efficiency capture by photosynthetic antennae via q(E) mechanism, governing electron transfer cytochrome b(6)f complex. Differential partitioning pmf into Δψ has...
Experimental protocols based on Electron Paramagnetic Resonance (EPR) and Raman spectroscopy are presented for the investigation of Fe(II) spin transition in Cu(II)-doped 1-D spin-crossover (SCO) nanoparticles type [Fe1−xCux(NH2trz)3]Br2 where x = 0.03 0.06 NH2trz 4-amino-1, 2, 4-triazole. The resulting were characterized using Transmission Microscopy (TEM), Infrared (IR) spectroscopy, powder X-ray diffraction (p-XRD). Magnetic susceptibility measurements revealed a dependence scan rate,...
A new method for direct covalent immobilization of protein molecules (including antibodies) on organic polymers with plasma-induced random micronanoscale topography and stable-in-time chemical functionality is presented. This achieved using a short (1-5 min) plasma etching simultaneous micronanotexturing process, followed by fast thermal annealing step, which induces accelerated hydrophobic recovery while preserving important created the plasma. Surface-bound biomolecules resist harsh...
Among the intermediate catalytic steps of water-oxidizing Mn
Purified flavohaemoglobin (HMP) of Escherichia coli reduces Fe(III) in a superoxide dismuatase (SOD)‐sensitive reaction, demonstrating anion generation during aerobic NADH oxidation. In vivo, sodA‐lacZ fusion activity was increased 3‐fold by introducing plasmid pPL341, containing the hmp gene, or growth with paraquat. The effects were additive and SOXS‐dependent. Thus HMP causes oxidative stress vivo. Activities hmp‐lacZ fusions stimulated himA mutant, repression both promoters integration...
The tetranuclear manganese cluster responsible for the oxidation of water in photosystem II cycles through five redox states denoted Si (i = 0, 1, 2, 3, 4). Progress has been made recently detection weak low-field EPR absorptions both perpendicular and parallel modes, associated with integer spin state S3 [Matsukawa, T., Mino, H., Yoneda, D., Kawamori, A. (1999) Biochemistry 38, 4072−4077]. We confirm observation these signals have obtained them high yield by illumination membranes, which...
The Escherichia coli haemoglobin-like flavohaemoprotein (Hmp) has been purified to near homogeneity using two chromatographic steps. prosthetic groups are identified as FAD and protohaem IX. SDS/PAGE indicated a molecular mass of 44 kDa for the monomeric protein consistent with amino-acid sequence deduced from hmp+ gene. protein, isolated, is in Fe(III) state, exhibiting absorbance maxima at 403.5, 540 (shoulder) 627 nm. ferrous carbonmonoxyferrous states resemble those haemoglobin, showing...
The sensitivity of the photosynthetic apparatus to ultraviolet-B (UV-B) irradiation was studied in cultures unicellular green alga Scenedesmus obliquus incubated low light (low photosynthetically active radiation intensity [LL]) and high (high [HL]) conditions, treated or not with exogenous polyamines. Biochemical physicochemical measurements showed that UV-B induces a decrease thylakoid-associated putrescine (Put) an increase spermine (Spm), so reduction Put/Spm ratio leads light-harvesting...
Hydrogen is a highly promising energy source with important social and economic implications. The ability of green algae to produce photosynthetic hydrogen under anaerobic conditions has been known for years. However, until today the yield production very low, limiting an industrial scale use. In present paper, 73 years after first report on H(2)-production from algae, we combinational biological system where biodegradation procedure one meta-substituted dichlorophenol (m-dcp) key element...
Polyamines (PAs) are nitrogenous molecules that indispensable for cell viability and with an agreed-on role in the modulation of stress responses. Tobacco plants downregulated SAMDC (AS-SAMDC) exhibit reduced PAs synthesis but normal levels PA catabolism. We used AS-SAMDC to increase our understanding on Surprisingly, at control conditions showed increased biomass altered developmental characteristics, such as height leaf number. On contrary, during salt vigor when compared WT. During...
The S(3) state of the water-oxidizing complex (WOC) photosystem II (PSII) is last that can be trapped before oxygen evolution occurs at transient S(4) state. A number EPR-detectable intermediates are associated with this critical preceding paper examined mainly decay cryogenic temperatures leading to formation a proton-deficient configuration S(2) termed S(2)'. This second examines all formed by near-IR light (NIR) excitation and compares these light-excitation products S(2)' rather set...
The soluble flavohaemoglobin (Hmp) of Escherichia coli contains haem B and FAD in a single 44 kDa polypeptide, shows NADH oxidase activity. oxidized protein reacted rapidly with the presence O2 to form an oxygenated species while flavin remained largely oxidized. Spectral kinetic analyses revealed rapid biphasic reduction oxygenation high-spin apparent relaxation times 6 64 ms at pH 8 25 degrees c, suggestive significant physiological role for protein. This was followed by monophasic time 92...
Photosystem II preparations poised in the S2···QA state produce no detectable intermediate during straightforward illumination at liquid helium temperatures. However, upon flash range of 77−190 K, they a transient which −10 °C advances to S3 or after rapid cooling 10 K gives rise 116 G wide metalloradical EPR signal. The latter decays with half-times on order few minutes, presumably by charge recombination, and can be regenerated repeatedly K. constraints for Tyr Z oxidation are attributed...