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81.
The aggregation of alpha-synuclein in dopaminergic neurons of the substantia nigra is a critical step in the pathogenesis of Parkinson's disease. We show that the antibiotic rifampicin inhibited alpha-synuclein fibrillation and disaggregated existing fibrils in a concentration-dependent manner. Size-exclusion chromatography data indicated that rifampicin stabilized alpha-synuclein as both a monomer and soluble oligomers comprised of partially folded alpha-synuclein. Experiments using aged samples of rifampicin indicated that the most active species in inhibiting fibrillation and disaggregating fibrils is an oxidation product of rifampicin, which was confirmed in experiments under anaerobic conditions. These results indicate that rifampicin-mediated inhibition of alpha-synuclein fibrillation and disaggregation of fibrils involves preferential stabilization of monomeric and soluble oligomeric forms, and that rifampicin potentially may have therapeutic application for Parkinson's disease. 相似文献
82.
We demonstrate the feasibility of optical bistability in an axially modulated nonlinear OmniGuide fiber through analytical theory and detailed numerical experiments. At 1.55-microm carrier wavelength, the in-fiber devices that we propose can operate with only a few tens of milliwatts of power, can have a nearly instantaneous response and recovery time, and can be shorter than 100 microm. 相似文献
83.
Roux P Derode A Peyre A Tourin A Fink M 《The Journal of the Acoustical Society of America》2000,107(2):L7-12
Acoustical imaging is based on the ability to focus an acoustic beam inside the zone of interest. This remains an issue through a high-order multiple scattering medium because the electronic delay lines that enable one to focus through a multiple scattering medium are a priori unknown. Using time-reversal principles, we show that images can be obtained through a very disordered medium. Surprisingly, the images are better than those obtained in a homogeneous medium with a classical imaging device. 相似文献
84.
Borisenko SV Golden MS Legner S Pichler T Durr C Knupfer M Fink J Yang G Abell S Berger H 《Physical review letters》2000,84(19):4453-4456
On the basis of angle-scanned photoemission data recorded using unpolarized radiation, with high (E,k) resolution, and an extremely dense sampling of k space, we resolve the current controversy regarding the normal state Fermi surface (FS) in Bi(2)Sr(2)CaCu(2)O(8+delta). The true picture is simple, self-consistent, and robust: the FS is holelike, with the form of rounded tubes centered on the corners of the Brillouin zone. Two further types of features are also clearly observed: shadow FSs, which are most likely to be due to short range antiferromagnetic spin correlations, and diffraction replicas of the main FS caused by passage of the photoelectrons through the modulated Bi-O planes. 相似文献
85.
86.
Jarkova E. Pleiner H. Mller H.-W. Fink A. Brand H.R. 《The European physical journal. E, Soft matter》2001,5(1):583-588
The European Physical Journal E - We derive hydrodynamic equations for nematic ferrofluids (ferronematics) in the limit that the magnetic degree of freedom has relaxed to its equilibrium value. We... 相似文献
87.
Samit Mandal J Gerl H Geissel K Hauschild M Hellström Z Janas I Kojouharov Y Kopatch RC Lemmon P Mayet Z Podolyak PH Regan H Schaffner C Schlegel J Simpson HJ Wollersheim 《Pramana》2001,57(1):161-164
Feasibility of gamma-ray spectroscopy at relativistic energies with exotic heavy-ions and new generation of germanium detectors
(segmented Clover) is discussed. An experiment with such detector array and radioactive is discussed. 相似文献
88.
V. M. Möhring K. Seevogel und G. Fink 《Fresenius' Journal of Analytical Chemistry》1986,323(4):330-333
Zusammenfassung Im Rahmen von kinetischen Untersuchungen zur Olefinpolymerisation mußten geringe Doppelbindungskonzentrationen in Polymeren mit stark differierender Struktur und Konsistenz exakt bestimmt werden. Die quantitative FTIR-Analyse der unterschiedlichen Doppelbindungen wurde dadurch optimiert, daß die Substanzen in der Schmelze vermessen wurden, die IR-Bandengruppen mittels rechnerisch erzeugter Bandenprofile entzerrt und die integralen Absorbanzen der olefinischen Banden bestimmt wurden. Die durch Analyse von Modellsubstanzen ermittelten integralen Extinktionskoeffizienten, bezogen auf 1 cm Schichtdicke und auf eine Doppelbindung pro 105 C-Atome liegen bei 0.93 (Vinyl), 0.95 (trans-Vinylen) und 1.04 (Vinyliden).
Determination of double bond concentrations in polyolefines by FTIR analysis
Summary In the course of kinetic investigations on olefin polymerization it was necessary to measure the concentration of double bonds in polymers with very variable structure and consistency as exactly as possible. For that purpose, the quantitative FTIR-analysis of the different double bonds was optimized by measuring the melted substances, by analysis of the groups of IR-bands with the help of computer generated band profiles and by determing the integral absorbances of the olefinic bands. The integral extinction coefficients of the vinyl, the trans-vinylene and the vinylidene double bonds were determined by the analysis of model compounds and values of 0.93, 0.95 and 1.04, respectively, for a sample of 1 cm thickness with one double bond per 105 carbon atoms were obtained.相似文献
89.
Ohne Zusammenfassung 相似文献
90.
E. Rothenbach R. Laster P. Kolbach R. Buse O. Heinisch D. Satava W. Piratzky H. Krwawnik A. Heiduschka Elisabeth Bischoff W. Windisch M. Hamburg G. Bode H. Fink E. Berwald V. I. Staněk P. Pavlas Â. Boas A. Herzfeld F. M. Wieninger E. Helm 《Analytical and bioanalytical chemistry》1935,101(11-12):443-448