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Ivana Kovačević Mirjana Popsavin Marko V. Rodić Vesna Kojić Velimir Popsavin 《Tetrahedron letters》2019,60(9):684-687
A new asymmetric synthesis of the naturally occurring styryl lactone cardiobutanolide and two novel analogues have been achieved starting from d-xylose. The key steps of the synthesis included an initial zinc mediated reductive THF-ring opening, stereoselective olefination and Sharpless asymmetric dihydroxylation. It was shown that cardiobutanolide (1) exhibits promising in vitro antitumour properties against certain human neoplastic cell lines. It was more potent than the commercial anticancer agent doxorubicin against three cell lines (K562, HL-60 and Raji). 相似文献
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Dušan Miljković Smiljana Velimirović János Csanádi Velimir Popsavin 《Journal of carbohydrate chemistry》2013,32(3):457-467
Abstract Some new partially or fully tosylated and/or mesylated 2, 5-anhydro-xylitol derivatives have been prepared in this work. Some of them represent the real optically active intermediates in an attempted synthesis of selected (+)-oxybiotin analogs, while the others, being racemic, serve only as easily available model-intermediates. 相似文献
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Thin deposits and patterning of room-temperature-switchable one-dimensional spin-crossover compounds
Cavallini M Bergenti I Milita S Kengne JC Gentili D Ruani G Salitros I Meded V Ruben M 《Langmuir : the ACS journal of surfaces and colloids》2011,27(7):4076-4081
We present a study on thin deposits and patterning of 1-D spin-crossover compounds Fe(II)-(L)(2)H](ClO(4))(3)·MeOH [L = 4'-(4'-pyridyl)-1,2':6'1'-bis- (pyrazolyl) pyridine] (1) that exhibit a reversible, thermally driven spin transition at room temperature. Micrometric rodlike crystals of 1 on silicon surfaces are achieved by drop casting and solvent annealing. We observed that the crystallinity of thin deposits and spin-transition properties critically depends on the deposition procedure. Furthermore, we proved processability and patterning using unconventional wet lithography that reduces the crystallite formation time by 1 order of magnitude. Thin deposits of 1 were characterized by atomic force microscopy, polarized optical microscopy and X-rays, and the switching properties were characterized by Raman spectroscopy. 相似文献
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The measures of information transfer which correspond to non-additive entropies have intensively been studied in previous decades. The majority of the work includes the ones belonging to the Sharma–Mittal entropy class, such as the Rényi, the Tsallis, the Landsberg–Vedral and the Gaussian entropies. All of the considerations follow the same approach, mimicking some of the various and mutually equivalent definitions of Shannon information measures, and the information transfer is quantified by an appropriately defined measure of mutual information, while the maximal information transfer is considered as a generalized channel capacity. However, all of the previous approaches fail to satisfy at least one of the ineluctable properties which a measure of (maximal) information transfer should satisfy, leading to counterintuitive conclusions and predicting nonphysical behavior even in the case of very simple communication channels. This paper fills the gap by proposing two parameter measures named the -q-mutual information and the -q-capacity. In addition to standard Shannon approaches, special cases of these measures include the -mutual information and the -capacity, which are well established in the information theory literature as measures of additive Rényi information transfer, while the cases of the Tsallis, the Landsberg–Vedral and the Gaussian entropies can also be accessed by special choices of the parameters and q. It is shown that, unlike the previous definition, the -q-mutual information and the -q-capacity satisfy the set of properties, which are stated as axioms, by which they reduce to zero in the case of totally destructive channels and to the (maximal) input Sharma–Mittal entropy in the case of perfect transmission, which is consistent with the maximum likelihood detection error. In addition, they are non-negative and less than or equal to the input and the output Sharma–Mittal entropies, in general. Thus, unlike the previous approaches, the proposed (maximal) information transfer measures do not manifest nonphysical behaviors such as sub-capacitance or super-capacitance, which could qualify them as appropriate measures of the Sharma–Mittal information transfer. 相似文献
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Slobodan M. Petrovi und Velimir D. Cani 《Fresenius' Journal of Analytical Chemistry》1967,228(5):339-341
Zusammenfassung Durch Dünnschicht-Chromatographie auf Maisstärke konnte die Trennung und der Nachweis von F–, Cl–, Br– und J–, bzw. ClO4
–, ClO3
–, BrO3
– und JO3
– durchgeführt werden. Drei verschiedene Fließmittel wurden verwendet. Die Nachweisgrenze liegt bei etwa 10–9 Mol.
Einen Teil der Versuche hat Dipl.-Chem. Ana Bem ausgeführt, wofür wir uns bedanken. 相似文献
Summary Separation and identification of F–, Cl–, Br–, I– and ClO4 –, ClO3 –, BrO3 – and JO3 – ions has been achieved by thin-layer chromatography on maize starch. Three different solvents are used. About 10–9 Mol could be detected.
Einen Teil der Versuche hat Dipl.-Chem. Ana Bem ausgeführt, wofür wir uns bedanken. 相似文献
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Maslyuk VV Bagrets A Meded V Arnold A Evers F Brandbyge M Bredow T Mertig I 《Physical review letters》2006,97(9):097201
Using density functional theory we perform theoretical investigations of the electronic properties of a freestanding one-dimensional organometallic vanadium-benzene wire. This system represents the limiting case of multidecker Vn(C6H6)(n+1) clusters which can be synthesized with established methods. We predict that the ground state of the wire is a 100% spin-polarized ferromagnet (half-metal). Its density of states is metallic at the Fermi energy for the minority electrons and shows a semiconductor gap for the majority electrons. We find that the half-metallic behavior is conserved up to 12% longitudinal elongation of the wire. Ab initio electron transport calculations reveal that finite size vanadium-benzene clusters coupled to ferromagnetic Ni or Co electrodes will work as nearly perfect spin filters. 相似文献