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81.
82.
Wienhöfer G Sorribes I Boddien A Westerhaus F Junge K Junge H Llusar R Beller M 《Journal of the American Chemical Society》2011,133(32):12875-12879
The first well-defined iron-based catalyst system for the reduction of nitroarenes to anilines has been developed applying formic acid as reducing agent. A broad range of substrates including other reducible functional groups were converted to the corresponding anilines in good to excellent yields at mild conditions. Notably, the process constitutes a rare example of base-free transfer hydrogenations. 相似文献
83.
Gröger K Baretić D Piantanida I Marjanović M Kralj M Grabar M Tomić S Schmuck C 《Organic & biomolecular chemistry》2011,9(1):198-209
Two novel guanidiniocarbonyl pyrrole-pyrene conjugates 3 and 4 as spectroscopic probes for ds-polynucleotides were synthesized and their interaction with different ds-DNAs/RNAs studied. Compared to a previously reported first set of conjugates (1 and 2) the significant extension and increased rigidity of the central part of the structure resulted in a switch of DNA binding mode from intercalative (previously studied derivatives 1 and 2 with a nonbinding and flexible linker) to minor groove binding of the two novel guanidiniocarbonyl-pyrrole-pyrene conjugates 3 and 4. These two compounds interact strongly with ds-DNAs, but only weakly with ds-RNA. The newly incorporated heterocyclic moieties within the central part of the structure of 3 and 4 were able to control by steric and hydrogen-bonding effects the alignment of the molecules within various, structurally different forms of DNA minor grooves, whereby even small differences in the position of the attached pyrene within the groove were reflected in different fluorimetric responses. In addition, 3 and 4 revealed intriguing in vitro selectivity among various human tumour cell lines. 相似文献
84.
The synthesis and characterization of a new difunctional coupler (4) based on trimethylolpropane (TMP) are described. The coupler is used to connect biologically active N-acetylglucosamine (GlcNAc) on amino-reactive microtiter plates and on star-shaped poly[(ethylene oxide)-stat-(propylene oxide)] hydrogel layers in microtiter plates. The biological activity of immobilized carbohydrates is determined using an enzyme-linked lectin assay. 相似文献
85.
Stelling A Salzer R Kirsch M Sobottka SB Geiger K Koch E Schackert G Steiner G 《Analytical and bioanalytical chemistry》2011,400(9):2745-2753
Established methods for characterization of tissue and diagnostics, for example histochemistry, magnetic resonance imaging
(MRI), X-ray tomography, or positron emission tomography (PET), are mostly not suitable for intra-operative use. However,
there is a clear need for an intra-operative diagnostics especially to identify the borderline between normal and tumor tissue.
Currently, vibrational spectroscopy techniques (both Raman and infrared) complement the standard methods for tissue diagnostics.
Vibrational spectroscopy has the potential for intra-operative use, because it can provide a biochemically based profile of
tissue in real time and without requiring additional contrast agents, which may perturb the tissue under investigation. In
addition, no electric potential needs to be applied, and the measurements are not affected by electromagnetic fields. Currently,
promising approaches include Raman fiber techniques and nonlinear Raman spectroscopy. Infrared spectroscopy is also being
used to examine freshly resected tissue ex vivo in the operating theater. The immense volume of information contained in Raman
and infrared spectra requires multivariate analysis to extract relevant information to distinguish different types of tissue.
The promise and limitations of vibrational spectroscopy methods as intra-operative tools are surveyed in this review. 相似文献
86.
87.
Seltmann J Müller K Klein S Lehmann M 《Chemical communications (Cambridge, England)》2011,47(23):6680-6682
V-shaped nematogens 1a-c and 2a-b with benzodithiophene bending units have been synthesised. The derivatives 1a-c comprise a flat core with a bending angle of 109°, which is almost the tetrahedral angle proposed to be optimal in the realization of mesogens forming a biaxial nematic thermotropic mesophase. 相似文献
88.
Rohr C Balbás Gambra M Gruber K Höhl C Malarek MS Scherer LJ Constable EC Franosch T Hermann BA 《Chemical communications (Cambridge, England)》2011,47(6):1800-1802
An interaction-site model can a priori predict molecular self-organisation on a new substrate in Monte Carlo simulations. This is experimentally confirmed with scanning tunnelling microscopy on Fréchet dendrons of a pentacontane template. Local and global ordering motifs, inclusion molecules and a rotated unit cell are correctly predicted. 相似文献
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90.