Refine
Has Fulltext
- no (147) (remove)
Year of publication
- 2014 (147) (remove)
Document Type
- Article (128)
- Doctoral Thesis (6)
- Review (6)
- Preprint (4)
- Other (2)
- Conference Proceeding (1)
Is part of the Bibliography
- yes (147)
Keywords
- Anisotropy effect (2)
- Arenesulfonamides (2)
- Aromaticity (2)
- Chelatoaromaticity (2)
- Cycloaddition (2)
- Janus emulsions (2)
- Trifluoromethanesulfonamide (2)
- X-ray (2)
- anomalous diffusion (2)
- arsenolipids present (2)
- biomaterials (2)
- carbohydrates (2)
- cod-liver (2)
- fatty-acids (2)
- hybrid materials (2)
- identification (2)
- living cells (2)
- metathesis (2)
- nanoparticles (2)
- physiological consequences (2)
- polyzwitterion (2)
- ruthenium (2)
- synthesis (2)
- tandem reaction (2)
- visible-light (2)
- (+)-Tephrodin (1)
- (Anti)aromaticity (1)
- 1,1-dimethyl-1,2,3,4-tetrahydrosiline (1)
- 1,3-Dienes (1)
- 1,5-Dienes (1)
- 3,4-dihydro-2H-pyran (1)
- 3,4-dihydro-2H-thiopyran (1)
- 3,6-Diazabicyclo[3.1.0]hexanes (1)
- 3,8-Diazabicyclo[3.2.1]octane (1)
- 3-Oxo-14 alpha, 15 alpha-epoxyschizozygine (1)
- 3D electrode structures (1)
- 4,4-dimethyl-3,4-dihydro-2H-1,4-thiasiline (1)
- 6 alpha-Hydroxy-alpha-toxicarol (1)
- Acetylpolyamine amidohydrolases (1)
- Adsorbent (1)
- Adsorption kinetic (1)
- Allylic oxidation (1)
- Alternating polyampholytes (1)
- Antibody (1)
- Antimicrobial activities (1)
- Aromatic or quinonoid (1)
- Base pairing (1)
- Binding assay (1)
- Binding pocket position (1)
- Block copolymers (1)
- Bulbine frutescens (1)
- C-13 (1)
- C-13 chemical shift difference Delta delta(C C) (1)
- Carbene ligands (1)
- Carbohydrates (1)
- Cassiamin A (1)
- Cassiamin B (1)
- Chemotaxonomy (1)
- Clay-polymer nanocomposite - CPN (1)
- Click chemistry (1)
- Conformational equilibrium (1)
- Copper Metal Complexes (1)
- Copper(II) (1)
- Cross coupling (1)
- Cryo-SEM (1)
- Crystal structure (1)
- Cyclic GMP (1)
- Cytotoxicity (1)
- DLS (1)
- DNA origami (1)
- DNA radiation damage (1)
- Dependent light scattering (1)
- Desorption (1)
- Diastereomers assignment (1)
- Dielectric properties (1)
- Dimeric anthraquinone (1)
- Diterpenoid (1)
- Dodonaea angustifolia (1)
- Dynamic NMR (1)
- ESI-MS (1)
- ESR (1)
- Emulsification (1)
- Emulsion destabilization (1)
- Escherichia coli (1)
- F-19 (1)
- FLNS (1)
- Fabry-Perot etalon (1)
- Flavanone (1)
- Flavone (1)
- Fluorescence (1)
- Fluorescence life time (1)
- Fluorescent nanoconjugate (1)
- Fokker-Planck equations (1)
- G quadruplexes (1)
- GC-MS (1)
- H-1 (1)
- Hapten (1)
- Hard sphere model in the Percus-Yevick Approximation (1)
- Hemiporphyrazines (1)
- High-cell-density culture (1)
- High-resolution spectrometer (1)
- Histone deacetylases (1)
- Homogeneous catalysis (1)
- Interfacial equilibrium (1)
- Interfacial tension (1)
- Ionic Liquid (1)
- Ionic liquids (1)
- Isolations (1)
- Janus drops (1)
- LIBS (1)
- Langmuir layers (1)
- Laser-induced breakdown spectroscopy (1)
- Magnetic properties (1)
- Maltose-modified PEI (1)
- Mammea usambarensis (1)
- Mammea-type coumarins (1)
- Mars (1)
- Mechanical properties (1)
- Metathesis (1)
- Methane (1)
- Methanogens (1)
- Michael addition (1)
- Microfluidics (1)
- Microorganism (1)
- Microparticles Reagentless assay (1)
- Micropolarity (1)
- Micropollutants (1)
- Microviscosity (1)
- Millettia dura; (1)
- Millettia leucantha (1)
- Millettia oblata ssp teitensis (1)
- Miniaturized cultivations (1)
- Molecular Probe (1)
- Monte-Carlo simulations (1)
- Multiple light scattering (1)
- Muonic molecules (1)
- N-azobenzylchitosan (1)
- N-methylnicotinamide (1)
- NMR (1)
- Nanosensor (1)
- Naphthyridines (1)
- Network structure (1)
- Nicotinamide (1)
- Occupation quotient pi*/pi (1)
- Optical oxygen sensor (1)
- Oxygen heterocycles (1)
- PQQ-GDH (1)
- Palladium (1)
- Paratope (1)
- Phenylanthraquinone (1)
- Phospholipids (1)
- Plasmid DNA production (1)
- Plasmodium falciparum (1)
- Platelet (1)
- Platinum group metals (1)
- Polarization elements (1)
- Polycyclic aromatic hydrocarbons (1)
- Polymer dispersions (1)
- Polymerized ionic liquids (1)
- Polypeptide (1)
- Polystyrene-divinylbenzene (1)
- Porphyrins (1)
- Pseudomonas aeruginosa (1)
- Push-pull alkynes (1)
- Push-pull effect (1)
- Quantum Chemical Calculations (1)
- Quantum dots (1)
- RP-HPLC (1)
- Radicals (1)
- Raman spectroscopy (1)
- Ring-current effect (1)
- Ruthenium (1)
- Schizozygane indoline alkaloid (1)
- Schizozygia coffaeoides (1)
- SnAr reaction (1)
- Solid-phase extraction (1)
- Spin probes (1)
- Spinning drop (1)
- Stereochemistry (1)
- Steric hindrance (1)
- Structural investigations (1)
- Structure revision (1)
- Sub-zero temperature (Celsius) (1)
- Sulphoxide (1)
- Supramolecular compounds (1)
- Surface exudates (1)
- Template phase (1)
- Tephrosia purpurea (1)
- Tephrosia villosa (1)
- Tetraoxo[8]circulenes (1)
- Tetraphenylethene Bioassay Fluorescent dye (1)
- Theoretical calculations (1)
- Thermal behavior (1)
- Thermoresponsive (1)
- Thiol-X (1)
- Through-space NMR shielding (TSNMRS) (1)
- TiO2 nanoparticles (1)
- ToF-SIMS (1)
- Wacker reaction (1)
- Water treatment (1)
- Wavelength modulation spectroscopy (laser spectroscopy) (1)
- Xanthone (1)
- Yukawa model in the Mean Spherical Approximation (1)
- absorbtion fine-structure (1)
- absorption (1)
- acinar-cells (1)
- adduct formation (1)
- adhesives (1)
- adsorption (1)
- amphiphilic polymer assembly (1)
- anti-polyelectrolyte effect (1)
- atomic force microscopy (1)
- attachment (1)
- augmented-wave method (1)
- azobenzenes (1)
- betaine (1)
- bioelectrochemistry (1)
- biomineralization (1)
- biosensor (1)
- bladder-cancer (1)
- block copolymers (1)
- brewster angle microscopy (1)
- brownian-motion (1)
- calcium phosphate (1)
- carcinogen exposure (1)
- carotenoids (1)
- cations (1)
- cell-death (1)
- cellulose (1)
- chemoradiation therapy (1)
- chitosan (1)
- chlorophyll (1)
- chromoionophore (1)
- click chemistry (1)
- cockroach salivary-glands (1)
- conductive polymer (1)
- construction (1)
- crosslinking (1)
- crystal structures (1)
- cyclization (1)
- cytosine methylation (1)
- cytosolic sodium (1)
- damage (1)
- de novo synthesis (1)
- density functional calculations (1)
- diffractive elements (1)
- diimine-complexes (1)
- direct bioelectrocatalysis (1)
- dna coiling (1)
- drugs (1)
- dyes/pigments (1)
- dynamics (1)
- electrically switchable gratings. (1)
- electron-transfer (1)
- ellipsometry (1)
- emulsion microscopy (1)
- energy transfer (1)
- enzyme reactions (1)
- europium complex (1)
- excimer UV light (1)
- excision-repair (1)
- excitation (1)
- excluded volume (1)
- exposure (1)
- fish (1)
- flight search patterns (1)
- fluctuation-dissipation theorem (1)
- fluorescence (1)
- fluorescence correlation spectroscopy (1)
- fluorescence label (1)
- fluorescence photobleaching recovery (1)
- folding kinetics (1)
- food contact material (1)
- fractional dynamics approach (1)
- frameworks (1)
- gas-phase (1)
- gene-expression (1)
- gene-regulation kinetics (1)
- genomic dna methylation (1)
- graphene oxide (1)
- graphite (1)
- grazing incidence X-ray diffraction (1)
- green (1)
- hela-cells (1)
- hemocompatibility (1)
- heterocycles (1)
- human-cells (1)
- hydrogen (1)
- imidazole (1)
- in-vitro (1)
- indicators (1)
- induced malignant-transformation (1)
- infection pathway (1)
- initio molecular-dynamics (1)
- intermittent chaotic systems (1)
- intracellular na+ (1)
- ion exchange (1)
- ion optodes (1)
- ionic liquid (1)
- ionic liquids (1)
- ionophore (1)
- isomerization (1)
- isotope effect (1)
- kinetic models (1)
- lactate (1)
- langevin equation (1)
- laser-enhanced nuclear fusion (1)
- levy flights (1)
- lifetime microscopy (1)
- lipid monolayer (1)
- low-energy electrons (1)
- macroITO (1)
- manganese (1)
- marine oils (1)
- mass-spectrometry (1)
- membrane (1)
- membranes (1)
- mesoporous materials (1)
- metabolites (1)
- metal coordination (1)
- methylmercury (1)
- methyltransferases dnmt3a (1)
- microemulsions (1)
- microporous organic polymers (1)
- mixtures (1)
- models (1)
- molecular dynamics simulations (1)
- molecular rods (1)
- molecular-mechanisms (1)
- monomer (1)
- morphology (1)
- nano clay (1)
- nanobioconjugate (1)
- nanoclusters (1)
- nematic phase (1)
- neurodegenerative diseases (1)
- neurotoxicity (1)
- oil (1)
- onformational analysis (1)
- oxidation (1)
- periplaneta-americana (1)
- photochemistry (1)
- photochromism (1)
- photoinduced radical polymerization (1)
- photon-counting statistics (1)
- photooxidation (1)
- photoswitches (1)
- pi-pi stacking (1)
- platelet aging (1)
- platelet function (1)
- platelet rich plasma (1)
- platelet storage (1)
- polarization gratings (1)
- poly(ADP-ribose) polymerase-1 (1)
- poly(epsilon-caprolactone) methacrylate (1)
- polyampholyte (1)
- polyelectrolyte adsorption (1)
- polyesterurethane (1)
- polyesterurethanes (1)
- polymer (1)
- polymer micelles (1)
- polymer/LC composites (1)
- polymerization (1)
- post-polymerization modification (1)
- protein binding (1)
- quantum dots (1)
- random-walks (1)
- rat (1)
- reactivity (1)
- rearrangement (1)
- reduction (1)
- relaxation NMR spectroscopy (1)
- repair (1)
- resonant formation (1)
- restricted N-S rotation (1)
- review (1)
- rp-hplc (1)
- sacrificial bonds (1)
- samples (1)
- seco-Anthraquinone (1)
- self-assembly (1)
- self-healing materials (1)
- sensors (1)
- shape-memory effect (1)
- side reaction (1)
- simulations (1)
- single-molecule analysis (1)
- single-particle tracking (1)
- single-strand breaks (1)
- sodium green (1)
- sol-gel processes (1)
- sorption (1)
- spatial-organization (1)
- statistical copolymer (1)
- substituent effects (1)
- sulfobetaine (1)
- super-intense laser pulses (1)
- supported gold (1)
- surface (1)
- surface charge (1)
- surface chemistry (1)
- switchable retarder (1)
- switches (1)
- systems (1)
- thermoresponsive materials (1)
- thimerosal (1)
- thio-dimethylarsinic acid (1)
- tight-binding (1)
- time random-walks (1)
- time-resolved fluorescence (1)
- transition (1)
- trivalent (1)
- two-dimensional phases (1)
- upper critical solution temperature (1)
- ventricular myocytes (1)
- visible light (1)
- vitro toxicological characterization (1)
- water (1)
- weak ergodicity breaking (1)
- whole blood (1)
- xanthophylls (1)
- zwitterionic group (1)
Institute
- Institut für Chemie (147) (remove)
New porous materials based on covalently connected monomers are presented. The key step of the synthesis is an acetalisation reaction. In previous years we used acetalisation reactions extensively to build up various molecular rods. Based on this approach, investigations towards porous polymeric materials were conducted by us. Here we wish to present the results of these studies in the synthesis of 1D polyacetals and porous 3D polyacetals. By scrambling experiments with 1D acetals we could prove that exchange reactions occur between different building blocks (evidenced by MALDI-TOF mass spectrometry). Based on these results we synthesized porous 3D polyacetals under the same mild conditions.
New porous materials based on covalently connected monomers are presented. The key step of the synthesis is an acetalisation reaction. In previous years we used acetalisation reactions extensively to build up various molecular rods. Based on this approach, investigations towards porous polymeric materials were conducted by us. Here we wish to present the results of these studies in the synthesis of 1D polyacetals and porous 3D polyacetals. By scrambling experiments with 1D acetals we could prove that exchange reactions occur between different building blocks (evidenced by MALDI-TOF mass spectrometry). Based on these results we synthesized porous 3D polyacetals under the same mild conditions.
H-1 NMR relaxation is used to study the self-assembly of a double thermoresponsive diblock copolymer in dilute aqueous solution. Above the first transition temperature, at which aggregation into micellar structures is observed, the trimethylsilyl (TMS)-labeled end group attached to the shell-forming block shows a biphasic T-2 relaxation. The slow contribution reflects the TMS groups located at the periphery of the hydrophilic shell, in agreement with a star-like micelle. The fast T-2 contribution corresponds to the TMS groups, which fold back toward the hydrophobic core, reflecting a flower-like micelle. These results confirm the formation of block copolymer micelles of an intermediate nature (i.e., of partial flower-like and star-like character), in which a part of the TMS end groups folds back to the core due to hydrophobic interactions.
NMR chemical shift predictions based on empirical methods are nowadays indispensable tools during resonance assignment and 3D structure calculation of proteins. However, owing to the very limited statistical data basis, such methods are still in their infancy in the field of nucleic acids, especially when non-canonical structures and nucleic acid complexes are considered. Here, we present an ab initio approach for predicting proton chemical shifts of arbitrary nucleic acid structures based on state-of-the-art fragment-based quantum chemical calculations. We tested our prediction method on a diverse set of nucleic acid structures including double-stranded DNA, hairpins, DNA/protein complexes and chemically-modified DNA. Overall, our quantum chemical calculations yield highly/very accurate predictions with mean absolute deviations of 0.3-0.6 ppm and correlation coefficients (r(2)) usually above 0.9. This will allow for identifying misassignments and validating 3D structures. Furthermore, our calculations reveal that chemical shifts of protons involved in hydrogen bonding are predicted significantly less accurately. This is in part caused by insufficient inclusion of solvation effects. However, it also points toward shortcomings of current force fields used for structure determination of nucleic acids. Our quantum chemical calculations could therefore provide input for force field optimization.
Three new copper(II) 4-nitrobenzoato coordination compounds (4-NO(2)bz(-) = 4-nitrobenzoate anions) with N-methylnicotinamide (mna) [Cu(4-NO(2)bz)(2)(mna)(2)(H2O)] (1), [Cu(4-NO(2)bz)(2)(mu-mna)(H2O)](2) (2) and [Cu(mu-4-NO(2)bz)(2)(mna)](2) (3) were synthesized and characterized. Due to a comparison, additional two related compounds [Cu(3,5-(NO2)(2)bz)(2)(mna)(2)(H2O)] (4) (nia = nicotinamide, 3,5-(NO2)(2)bz(-) = 3,5-dinitrobenzoate anions) and [Cu(mu-2-NO(2)bz)(2)(mna)](2) (5) (2-NO(2)bz(-) = 2-nitrobenzoate anions) were isolated. The mononuclear compounds with mna 1 and nia 4 show CuO2N2O chromophores with the water molecule placed at the apex of the square pyramid. The square-pyramidal coordination sphere CuO3NO in 2 differs to CuO2N2O in 1 and 4. Differently, the water molecule is in 2 at the basal-plane, while two mna molecules serve also as bridges via N-py and 0-amido enabling a dinuclear molecular structure 1, 2 and 4 are paramagnetic though a dinuclear structure is seen in 2, while a clear-cut strong antiferromagnetic (AFM) coupling (2J -300 cm(-1)) is found for the compounds 3 and 5. (C) 2014 Elsevier Ltd. All rights reserved.
Motivated by recent atomic manipulation experiments, we report quantum chemical calculations for chemi- and physisorption minima of chlorobenzene on the Si(111)-7x7 surface. A density functional theory cluster approach is applied, using the B3LYP hybrid functional alongside Grimme's empirical dispersion corrections (D3). We were able to identify chemisorption sites of binding energies of 1.6 eV and physisorption energies of 0.6 eV, both in encouraging agreement with the trend of experimental data. The cluster approach opens up the possibility of a first-principles based dynamical description of STM manipulation experiments on this system, the interpretation of which involves both the chemi- and physisorbed states. However, we found that special care has to be taken regarding the choice of clusters, basis sets, and the evaluation of the dispersion corrections.
A class of adsorbents currently receiving growing attention is the clay-polymer nanocomposite (CPN) adsorbents. CPNs effectively treat water by adsorption and flocculation of both inorganic and organic micropollutants from aqueous solutions. Some of these CPNs - when modified with biocides - also have the ability to efficiently remove microorganisms such as Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Candida albicans from water. CPNs are far more easily recovered from aqueous media than neat clay. They also exhibit far better treatment times than either polymer or clay adsorbents. They have higher adsorption capacity and better life cycles compared with clay alone. CPNs therefore show an excellent potential as highly efficient water and waste treatment agents.
This article reviews the various CPNs that have been prepared recently and used as adsorbents in the removal of micropollutants (inorganic, organic and biological) from aqueous solutions. A special focus is placed on CPNs that are not only interesting from an academic point of view but also effectively reduce the concentration of micropollutants in water to safe limits and also on new developments bordering on CPN use as water treatment agent that have not yet realized their full potential. (C) 2014 Elsevier B.V. All rights reserved.
This study aims to further mechanistically understand toxic modes of action after chronic inorganic arsenic exposure. Therefore long-term incubation studies in cultured cells were carried out, to display chronically attained changes, which cannot be observed in the generally applied in vitro short-term incubation studies. Particularly, the cytotoxic, genotoxic and epigenetic effects of an up to 21 days incubation of human urothelial (UROtsa) cells with pico- to nanomolar concentrations of iAsIII and its metabolite thio-DMAV were compared. After 21 days of incubation, cytotoxic effects were strongly enhanced in the case of iAsIII and might partly be due to glutathione depletion and genotoxic effects on the chromosomal level. These results are in strong contrast to cells exposed to thio-DMAV. Thus, cells seemed to be able to adapt to this arsenical, as indicated among others by an increase in the cellular glutathione level. Most interestingly, picomolar concentrations of both iAsIII and thio-DMAV caused global DNA hypomethylation in UROtsa cells, which was quantified in parallel by 5-medC immunostaining and a newly established, reliable, high resolution mass spectrometry (HRMS)-based test system. This is the first time that epigenetic effects are reported for thio-DMAV; iAsIII induced epigenetic effects occur in at least 8000 fold lower concentrations as reported in vitro before. The fact that both arsenicals cause DNA hypomethylation at really low, exposure-relevant concentrations in human urothelial cells suggests that this epigenetic effect might contribute to inorganic arsenic induced carcinogenicity, which for sure has to be further investigated in future studies.
A cluster approach extended to the ONIOM methodology has been applied using several density functionals and Moller-Plesset perturbation theory (MP2) to simulate the adsorption of selected nitrogen-containing compounds [NCCs, 2,4,6-trinitrotoluene (TNT), 2,4-dinitrotoluene (DNT), 2,4-dinitroanisole (DNAN), and 3-nitro-1,2,4-triazole-5-one (NTO)] on the hydroxyated (100) surface of a-quartz. The structural properties were calculated using the M06-2X functional and 6-31G(d,p) basis set. The M06-2X-D3, PBE-D3, and MP2 methods were used to calculate the adsorption energies. Results have been compared with the data from other studies of adsorption of compounds of similar nature on silica. Effect of deformation of the silica surface and adsorbates on the binding energy values was also studied. The atoms in molecules (AIM) analysis was employed to characterize the adsorbate-adsorbent binding and to calculate the bond energies. The silica surface shows different sorption affinity toward the chemicals considered depending on their electronic structure. All target NCCs are physisorbed on the modeled silica surface. Adsorption occurs due to the formation of multiple hydrogen bonds between the functional groups of NCCs and surface silanol groups. Parallel orientation of NCCs interacting with the silica surface was found to be favorable when compared with perpendicularly oriented NCCs. NTO was found to be the most strongly adsorbed on the silica surface among all of the considered compounds. Dispersion correction was shown to play an important role in the DFT calculations of the adsorption energies of silica-NCC systems.