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71.
A catalytic asymmetric synthesis of (+)-aza-galacto-fagomine (AGF) – the most promising compound for the pharmacological chaperone therapy of Krabbe disease – was accomplished in six steps, in 14% overall yield. The synthesis hinges on the combination of organocatalyzed aldolization and reductive hydrazination. 相似文献
72.
Vesna V. Vodnik Jasna V. Vuković Jovan M. Nedeljković 《Colloid and polymer science》2009,287(7):847-851
The optical properties of silver nanoparticles embedded in poly(methylmethacrylate) (PMMA) was investigated as well as the
influence of silver nanoparticles on the thermal properties of polymer matrix. The average size and particle size distribution
of silver nanoparticles was determined using transmission electron microscopy. The obtained transparent nanocomposite films
were optically characterized using UV-Vis and FTIR spectroscopy. Thermal stability of polymer matrix was improved upon incorporation
of small amount of silver nanoparticles. Also, silver nanoparticles have pronounced effect on thermo-oxidative stability of
PMMA matrix. The glass transition temperatures of nanocomposites are lower compared to the pure polymer. 相似文献
73.
Jelena Pešić Jasna Vujin Tijana Tomašević-Ilić Marko Spasenović Radoš Gajić 《Optical and Quantum Electronics》2018,50(7):291
We calculate the dielectric function within the framework of the random-phase approximation (RPA) based on DFT ground-state calculations, starting from eigenvectors and eigenvalues. The final goal of our theoretical work is a comparison to corresponding experimental data. We compare our computational results with optical measurements on \(\hbox {MoS}_2\) and \(\hbox {WS}_2\) nanoflakes. \(\hbox {MoS}_2\) and \(\hbox {WS}_2\) were exfoliated by ultrasonic treatment in high-boiling point organic solvent and characterized using UV–VIS spectrophotometry. We find that DFT-RPA yields a good, computationally inexpensive first approximation of the imaginary part of the dielectric function, although excitonic effects require more complex code and extra computing power. 相似文献
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75.
Pagano N Maksimoska J Bregman H Williams DS Webster RD Xue F Meggers E 《Organic & biomolecular chemistry》2007,5(8):1218-1227
A general route to ruthenium pyridocarbazole half-sandwich complexes is presented and applied to the synthesis of sixteen new compounds, many of which have modulated protein kinase inhibition properties. For example, the incorporation of a fluorine into the pyridine moiety increases the binding affinity for glycogen synthase kinase 3 by almost one order of magnitude. These data are supplemented with cyclic voltammetry experiments and a protein co-crystallographic study. 相似文献
76.
Mormann M Zamfir AD Seidler DG Kresse H Peter-Katalinić J 《Journal of the American Society for Mass Spectrometry》2007,18(2):179-187
A combination of negative ion nano-electrospray ionization Fourier-transform ion cyclotron resonance and quadrupole time-of-flight mass spectrometry was applied to analysis of oversulfation in glycosaminoglycan oligosaccharides of the chondroitin sulfate type from bovine aorta. Taking advantage of the high-resolution and high mass accuracy provided by the FT-ICR instrument, a direct compositional assignment of all species present in the mixture can be obtained. An oligosaccharide fraction containing mainly hexasaccharides exhibited different levels of sulfation, indicated by the presence of species with regular sulfation pattern as well as oversulfated oligosaccharides with one additional sulfate group. Oversulfation can be directly identified from the high-resolution/high mass accuracy FT-ICR mass spectra according to their specific isotopic fine structure. Location of sulfate groups was analyzed by Q-TOF MS and low-energy CID MS/MS. Tetrasulfated hexasaccharides were analyzed by use of collision-induced dissociation at variable collision energy for an unambiguous assignment of the attachment site of the sulfate groups by minimizing unspecific neutral losses. Cleavage of glycosidic bonds gave rise to B- and C-type ions and their respective complementary Y- and Z-type fragment ions. 相似文献
77.
Daniel T. Mainz Jasna J. Klicic Richard A. Friesner Jean-Marc Langlois Jason K. Perry 《Journal of computational chemistry》1997,18(15):1863-1874
We have developed a parameterization enabling ab initio electronic structure calculation via the PS-GVB program on transition-metal-containing systems using two standard effective core potential basis sets. Results are compared with Gaussian-92 for a wide range of complexes, and superior performance is demonstrated with regard to computational efficiency for single-point energies and geometry optimization. Additionally, the initial guess strategy in PS-GVB is shown to provide considerably more reliable convergence to the ground state. © 1997 John Wiley & Sons, Inc. J Comput Chem 18 : 1863–1874, 1997 相似文献
78.
Kosicek M Kirsch S Bene R Trkanjec Z Titlic M Bindila L Peter-Katalinic J Hecimovic S 《Analytical and bioanalytical chemistry》2010,398(7-8):2929-2937
There is emerging evidence that lipids play an important role in many neurodegenerative processes, for example in Alzheimer's disease (AD). Although different lipid alterations in the AD brain have been reported, there have only been very few investigations of lipid changes in the cerebrospinal fluid (CSF). Recent developments in mass spectrometry (MS) have enabled fast and sensitive detection of lipid species in different biological matrixes. In this study we developed an on-line HPLC-MS method for phospholipid profiling in the CSF based on nano-HPLC separation using an Amide column and detection with electrospray (ESI) quadrupole-time of flight (QTOF) MS. We achieved good separation, reproducibility, and sensitivity in monitoring of the major phospholipid classes, phosphatidylethanolamine (PE), phosphatidylcholine (PC), phosphatidylinositol (PI), and sphingomyelin (SM) in CSF. To emphasize the applicability of the method, a pilot study was performed on a group of CSF samples (N = 16) from individuals with probable AD and non-demented controls. We observed a statistically significant increase of SM levels (24.3 ± 2.4%) in CSF from probable AD individuals vs. controls. Our findings indicate that SM levels in the CSF could potentially provide a new lead in AD biomarker research, and show the potential of the method for disease-associated CSF phospholipid screening. 相似文献
79.
80.
Nadja Frömmgen Dimiter L. Balabanski Mark L. Bissell Jacek Bieroń Klaus Blaum Bradley Cheal Kieran Flanagan Stephan Fritzsche Christopher Geppert Michael Hammen Magdalena Kowalska Kim Kreim Andreas Krieger Rainer Neugart Gerda Neyens Mustafa M. Rajabali Wilfried Nörtershäuser Jasna Papuga Deyan T. Yordanov 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2015,69(6):164