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71.
Paweł K. Zarzycki Magdalena M. ŚlączkaMagdalena B. Zarzycka Elżbieta WłodarczykMichał J. Baran 《Analytica chimica acta》2012
The main goal of present paper is to demonstrate the separation and detection capability of micro-TLC technique involving simple one step liquid extraction protocols of complex materials without multi-steps sample pre-purification. In the present studies target components (cyanobacteria pigments, lipids and fullerenes) were isolated from heavy loading complex matrices including spirulina dried cells, birds’ feathers and fatty oils as well as soot samples derived from biomass fuel and fossils-fired home heating systems. In each case isocratic separation protocol involving less that 1 mL of one component or binary mixture mobile phases can be completed within time of 5–8 min. Sensitive detection of components of interest was performed via fluorescence or staining techniques using iodine or phosphomolybdic acid. Described methodology can be applied for fast fractionation or screening of whole range of target substances as well as chemo-taxonomic studies and fingerprinting of complex mixtures, which are present in raw biological or environmental samples. 相似文献
72.
73.
O. V. Buganov A. D. Zamkovets A. N. Ponyavina S. A. Tikhomirov L. V. Baran 《Journal of Applied Spectroscopy》2011,78(5):686-691
Differential transient absorption spectra have been studied for planar densely packed Ag/Na3AlF6 nanostructures under ultrashort laser pulse excitation. The nanostructures were fabricated by sequential thermal evaporation
of cryolite (Na3AlF6) and silver in vacuo onto glass and quartz substrates. A nonmonotonic variation in relaxation times of induced changes in
a surface plasmon resonance band was observed with an increase in the metal surface density that resulted in nanoparticle
size growth and structural modification of the densely packed layer. The tendency of the relaxation times to vary nonmonotonically
is explained by both features of intrinsic size effects and electron-tunneling processes in plasmonic densely packed nanostructures
of various topologies. 相似文献
74.
Marta Bugaj Piotr A. Baran Piotr Bernatowicz Patrycja Brożek Krystyna Kamieńska‐Trela Adam Krówczyński Bohdan Kamieński 《Magnetic resonance in chemistry : MRC》2009,47(10):830-842
A series of aryl‐substituted enaminoketones and their thio analogues in CDCl3 solution and in the solid state were studied by the use of high‐resolution 1H and 13C as well as 13C cross polarization magic angle spinning (CP MAS) NMR spectra in combination with gauge including atomic orbitals‐density functional theory (GIAO‐DFT) calculations performed at the B3PW91/6–311 + + G(d,p) level of theory using the B3PW91/6‐311 + + G(d,p)‐optimized geometries. The analysis of the 13C NMR spectra in solution was done by using the Incredible Natural Abundance DoublE QUAntum Transfer Experiment (INADEQUATE) technique, whereas trends observed in the 13C shielding constants, calculated for the compounds studied, were a great help in assigning most of the signals in the 13C CP MAS NMR spectra. It was established on the basis of the experimental and theoretical NMR data that both groups of compounds exist in the form of Z‐s‐Z‐s‐E isomers in CDCl3 solution as well as in the solid state, with the NH hydrogen atom involved in intramolecular hydrogen bonding. This conclusion is in agreement with the fact that some of the compounds studied reveal liquid‐crystalline properties. Three‐bond H, H and C, H coupling constants measured in solution played a crucial role in the structure elucidation. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
75.
M. Baran 《Acta Mathematica Hungarica》1998,80(3):211-224
In this paper, various generalizations of the usual completely regular spaces and completely normal spaces to topological categories are given. Moreover, the relationships among various forms of these generalizations are investigated. 相似文献
76.
77.
Distribution of the strength of acid sites in mildly steamed HZSM-5 studied by IR spectroscopy 总被引:1,自引:0,他引:1
Jerzy Datka Barbara Gil Pawel Baran Brigitte Staudte 《Reaction Kinetics and Catalysis Letters》2002,77(2):209-217
Steaming resulted in modification of the distribution of acid strength of OH groups. The contribution of less acidic sites increased and new, very strongly acidic hydroxyls characterized by IR band at 3590 cm-1 appeared. 相似文献
78.
T. Bezrodna I. Chashechnikova L. Dolgov G. Puchkovska Ye. Shaydyuk N. Lebovka V. Moraru J. Baran H. Ratajczak 《Liquid crystals》2005,32(8):1005-1012
Investigations of montmorillonite (MMT) clay mineral modification effects on electro-optical properties of nanocomposites, based on the nematic liquid crystal 4-pentyl-4'-cyanobiphenyl (5CB) and MMT have been carried out. Only the composite with MMT modified by an organic surface-active substance, dioctadecyldimethylammonium chloride, has been shown to manifest electro-optical memory effect and contrast. A polar dopant (acetone), added to the mixture, significantly increases composite homogeneity. Results of IR spectroscopy measurements lead to the conclusion, that there is a mutual influence of components on each other in organoclay systems, which appears as an alignment of near-surface layers of both the organic and inorganic components of the composite. Due to such interactions these systems show electro-optical contrast and memory effect. A composite with organophobic Na-MMT does not show these electro-optical properties, due to the absence of component interactions, as shown by IR spectroscopic data. 相似文献
79.
M. Di Toro V. Baran M. Colonna V. Greco S. Maccarone M. Cabibbo 《The European Physical Journal A - Hadrons and Nuclei》2002,13(1-2):155-161
In the reaction dynamics of intermediate-energy radioactive beams we can probe highly asymmetric nuclear matter in compressed
as well as dilute phases. In this report some predictions are presented, based on analytical results as well as on reaction
simulations. We suggest a series of experiments with RIB aimed to shed light on isospin properties of nuclear interactions
in the medium.
Received: 1 May 2001 / Accepted: 4 December 2001 相似文献
80.
CH Oxidation of Ingenanes Enables Potent and Selective Protein Kinase C Isoform Activation 下载免费PDF全文
Dr. Yehua Jin Dr. Chien‐Hung Yeh Dr. Christian A. Kuttruff Dr. Lars Jørgensen Dr. Georg Dünstl Dr. Jakob Felding Dr. Swaminathan R. Natarajan Prof. Dr. Phil S. Baran 《Angewandte Chemie (International ed. in English)》2015,54(47):14044-14048
Ingenol derivatives with varying degrees of oxidation were prepared by two‐phase terpene synthesis. This strategy has allowed access to analogues that cannot be prepared by semisynthesis from natural ingenol. Complex ingenanes resulting from divergent C? H oxidation of a common intermediate were found to interact with protein kinase C in a manner that correlates well with the oxidation state of the ingenane core. Even though previous work on ingenanes has suggested a strong correlation between potential to activate PKCδ and induction of neutrophil oxidative burst, the current study shows that the potential to activate PKCβII is of key importance while interaction with PKCδ is dispensable. Thus, key modifications of the ingenane core allowed PKC isoform selectivity wherein PKCδ‐driven activation of keratinocytes is strongly reduced or even absent while PKCβII‐driven activation of neutrophils is retained. 相似文献