Search results for "OMOP"
showing 10 items of 624 documents
Predictive First-Principles Modeling of a Photosynthetic Antenna Protein: The Fenna–Matthews–Olson Complex
2020
High efficiency of light harvesting in photosynthetic pigment–protein complexes is governed by evolutionary-perfected protein-assisted tuning of individual pigment properties and interpigment interactions. Due to the large number of spectrally overlapping pigments in a typical photosynthetic complex, experimental methods often fail to unambiguously identify individual chromophore properties. Here, we report a first-principles-based modeling protocol capable of predicting properties of pigments in protein environment to a high precision. The technique was applied to successfully uncover electronic properties of the Fenna–Matthews–Olson (FMO) pigment–protein complex. Each of the three subunit…
Do Phonological Codes Constrain the Selection of Orthographic Codes in Written Picture Naming?
2001
Sound-to-print consistency of picture labels was manipulated in five experiments to investigate whether phonological codes constrain the selection of orthographic codes in written picture naming. In Experiments 1 and 2, participants wrote down picture names which were inconsistent or consistent in the phono-orthographic mapping defined either at the level of the word unit, i.e., heterographic homophones versus nonhomophones (Experiment 1), or at the sublexical level (Experiment 2). In neither experiment did phonographic consistency affect written latencies. Although more errors were observed for inconsistent than for consistent picture names, the observation of a similar error pattern in an…
Ferrocene-quinoxaline Y-shaped chromophores as fascinating second-order NLO building blocks for long lasting highly active SHG polymeric films
2016
The first example of a Y-shaped ferrocene quinoxaline derivative with a surprisingly high and stable second harmonic generation (SHG) response in composite polymeric films is reported. The interesting quadratic hyperpolarizability values of different substituted Y-shaped chromophores are also investigated in solution by the EFISH technique.
Gold(I)-doped films: new routes for efficient room temperature phosphorescent materials
2021
The synthesis of four novel gold(I)-phosphane complexes coordinated to 9-phenanthrene chromophore has been carried out through the reaction of 9-phenanthreneboronic acid and the corresponding AuClPR3 (PR3 = PPh3 for triphenylphosphane (1a); 1,4-bis(diphenylphosphanyl)butane or dppb (2b); bis(diphenylphosphanyl)acetylene or dppa (2c); (AuCl)2(diphos) (diphos = bis(diphenylphosphanyl)methane or dppm (3)) sources. The X-ray crystal structures of compounds 1a and 2b show the existence of MOF-like intermolecular assemblies that contain empty inner cavities in the absence of aurophilic contacts. In contrast, the formation of a tetranuclear complex with intramolecular aurophilic interactions was e…
Luminescence and Light‐Driven Energy and Electron Transfer from an Exceptionally Long‐Lived Excited State of a Non‐Innocent Chromium(III) Complex
2019
Abstract Photoactive metal complexes employing Earth‐abundant metal ions are a key to sustainable photophysical and photochemical applications. We exploit the effects of an inversion center and ligand non‐innocence to tune the luminescence and photochemistry of the excited state of the [CrN6] chromophore [Cr(tpe)2]3+ with close to octahedral symmetry (tpe=1,1,1‐tris(pyrid‐2‐yl)ethane). [Cr(tpe)2]3+ exhibits the longest luminescence lifetime (τ=4500 μs) reported up to date for a molecular polypyridyl chromium(III) complex together with a very high luminescence quantum yield of Φ=8.2 % at room temperature in fluid solution. Furthermore, the tpe ligands in [Cr(tpe)2]3+ are redox non‐innocent, …
Structural basis for light control of cell development revealed by crystal structures of a myxobacterial phytochrome
2018
Phytochromes are red-light photoreceptors that were first characterized in plants, with homologs in photosynthetic and non-photosynthetic bacteria known as bacteriophytochromes (BphPs). Upon absorption of light, BphPs interconvert between two states denoted Pr and Pfr with distinct absorption spectra in the red and far-red. They have recently been engineered as enzymatic photoswitches for fluorescent-marker applications in non-invasive tissue imaging of mammals. This article presents cryo- and room-temperature crystal structures of the unusual phytochrome from the non-photosynthetic myxobacterium Stigmatella aurantiaca (SaBphP1) and reveals its role in the fruiting-body formation of this ph…
A Functionalized Noncovalent Macrocyclic Multiporphyrin Assembly from a Dizinc(II) Bis-Porphyrin Receptor and a Free-Base Dipyridylporphyrin
2003
The bis-porphyrin system ZnP 2 , in which two zinc porphyrins are connected by a phenanthroline linker in an oblique fashion, acts as a bifunctional receptor towards the complexation of free-base meso-5,10-bis(4'-pyridyl)-15,20-diphenylporphyrin (4'-cisDPyP). In solution, NMR spectroscopy evidenced quantitative formation of the tris-porphyrin macrocyclic assembly ZnP 2 (4'-cisDPyP), in which the two fragments are held together by two axial 4'-N(pyridyl)-Zn interactions. The remarkable stability of the edifice (an association constant of about 6 x 10 8 M - 1 was determined by UV/Vis absorption and emission titration experiments in toluene) is due to the almost perfect geometrical match betwe…
Metal complexes of phenobarbituric acid. Chelating behavior of the phenobarbiturate ring. Anticonvulsant properties of the K2[Cu(N-methylphenobarbitu…
1992
Abstract Na2Ni(phenobarbiturato)4·3H2O, Na2Ni3(phenobarbiturato)2(OH)6·4H2O, and NaZn(phenobarbiturato)2(OH)·H2O derivatives were prepared from Ni(II) and Zn(II) and phenobarbital. The Na2Ni(phenobarbiturato)4·3H2O complex is diamagnetic and isostructural with the complex previously reported, Na2Cu(phenobarbiturato)4, suggesting a square-planar environment around the Ni(II) ion. The DMF solutions of this complex show the existence of two species. The EPR spectra of the Cu(II) doped complex show the hyperfine and superhyperfine structures. The covalence parameters α2, β2, and δ2 show a strong bonding in the equatorial plane and suggests the formation of a [CuN4] chromophore. The anticonvulsa…
Synthesis, spectral and magnetic properties of two different 2-nitrobenzoatocopper(II) complexes containing N,N-diethylnicotinamide
2008
Abstract Two structurally different complexes, [Cu2(2-NO2Bz)4(denia)1]n (1) and [Cu(2-NO2Bz)2(denia)2(H2O)2] (2), were prepared from the same reaction (where 2-NO2Bz = 2-nitrobenzoate, denia = N,N-diethylnicotinamide) and they are reported together with [Cu2(2-NO2Bz)4(DMF)2] (3) (DMF = N,N-dimethylformamide). The compounds under study were characterized by elemental analysis, electronic, IR and EPR spectra, magnetic measurements over the temperature range of 1.8–300 K and X-ray analysis. The molecular structure of (1) is polymeric, (2) is monomeric and (3) is dimeric. In the polymeric chain of (1), the denia molecules serve as bridges between dimeric Cu2(2-NO2bz)4 units. Each Cu(II) atom ha…
Radial and peripheral clines in northern polymorphic populations of Philaenus spumarius
2009
Geographic variability in the colour polymorphism of Philaenus spumarius (Homoptera) was investigated in the northern parts of Finland, Norway and Sweden. The investigation was directed mainly at peripheral populations south of the Baltic—Arctic divide. The colour phenotypes were found to differ in their “north tolerance”. The phenotypes typ (pt/pt) and lat (pt/pt) were the most, and the phenotype tri (pt/pT) the least tolerant to marginal conditions. Differences in “north tolerance” between the phenotypes cause radial clines to be present in allele frequencies. The radial clines may be caused by the combined effect of several different factors. These include shortness of the thermal growth…