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排序方式: 共有216条查询结果,搜索用时 15 毫秒
131.
eljka Ban Zrinka Kara
i Sanja Tomi Hashem Amini Todd B. Marder Ivo Piantanida 《Molecules (Basel, Switzerland)》2021,26(16)
Novel dyes were prepared by simple “click CuAAC” attachment of a triarylborane–alkyne to the azide side chain of an amino acid yielding triarylborane dye 1 which was conjugated with pyrene (dye 2) forming a triarylborane–pyrene FRET pair. In contrast to previous cationic triarylboranes, the novel neutral dyes interact only with proteins, while their affinity to DNA/RNA is completely abolished. Both the reference triarylborane amino acid and triarylborane–pyrene conjugate bind to BSA and the hDPP III enzyme with high affinities, exhibiting a strong (up to 100-fold) fluorescence increase, whereby the triarylborane–pyrene conjugate additionally retained FRET upon binding to the protein. Furthermore, the triarylborane dyes, upon binding to the hDPP III enzyme, did not impair its enzymatic activity under a wide range of experimental conditions, thus being the first non-covalent fluorimetric markers for hDPP III, also applicable during enzymatic reactions with hDPP III substrates. 相似文献
132.
Moftah OA Grbavčić S Zuža M Luković N Bezbradica D Knežević-Jugović Z 《Applied biochemistry and biotechnology》2012,166(2):348-364
Olive oil cake is a by-product from the olive oil processing industry and can be used for the lipase and protease production
by Candida utilis in solid state fermentation. Different carbon and nitrogen sources were evaluated, and the results showed that the supplementation
of the substrate with maltose and starch as carbon sources and yeast extract as a nitrogen source significantly increased
the lipase production. The best results were obtained with maltose, whereas rather low lipase and protease activities were
found with glucose and oleic acid. Response surface methodology and a five-level–three-factor central composite rotatable
design were used to evaluate the effects of the initial moisture content, inoculum size and fermentation time on both lipase
and protease activity levels. A lipase activity value of ≈25 U g-1 and a protease activity value of 110 U g-1 were obtained under the optimized fermentation conditions. An alkaline treatment of the substrate appeared to be efficient,
leading to increases of 39% and 133% in the lipase and protease production, respectively. The results showed that the olive
cake could be a good source for enzyme production by solid state fermentation. 相似文献
133.
Sanja Singer Sa?a Singer Vedran Novakovi? Aleksandar U??umli? Vedran Dunjko 《Numerical Algorithms》2012,59(1):1-27
We describe two main classes of one-sided trigonometric and hyperbolic Jacobi-type algorithms for computing eigenvalues and
eigenvectors of Hermitian matrices. These types of algorithms exhibit significant advantages over many other eigenvalue algorithms.
If the matrices permit, both types of algorithms compute the eigenvalues and eigenvectors with high relative accuracy. We
present novel parallelization techniques for both trigonometric and hyperbolic classes of algorithms, as well as some new
ideas on how pivoting in each cycle of the algorithm can improve the speed of the parallel one-sided algorithms. These parallelization
approaches are applicable to both distributed-memory and shared-memory machines. The numerical testing performed indicates
that the hyperbolic algorithms may be superior to the trigonometric ones, although, in theory, the latter seem more natural. 相似文献
134.
Novak P Tatić I Tepes P Kostrun S Barber J 《The journal of physical chemistry. A》2006,110(2):572-579
The three-dimensional structures of oleandomycin (1) and its derivatives oleandomycin-9-oxime (2) and 10,11-anhydrooleandomycin (3) were determined in different solvents by the combined use of NMR and molecular modeling methods. The experimental NMR data were compared with the results of molecular modeling and known crystal structures of the related molecules. It was shown that the dominant conformation of the lactone ring is the folded-out conformation with some amounts of the folded-in one depending on the solvent and temperature, while desosamine and cladinose sugars adopt the usual chair conformations. Modeling calculations provided evidence for conformational changes in the upper lactone region as well. Saturation transfer difference (STD) NMR experiments have provided information on the binding epitopes of 1-3 in complexes with E. coli ribosomes. The obtained molecular surfaces in close contact with ribosomes were compared with recently available 3D structures of the related macrolide-ribosome complexes, and the observed differences were discussed. The knowledge gained from this study can serve as a platform for the design of novel macrolides with an improved biological profile. 相似文献
135.
Sanja Sakan Dragana ?or?evi? Gordana Devi? Dubravka Reli? Ivan An?elkovi? Jelena Ðuri?i? 《Microchemical Journal》2011,99(2):492-502
The aim of this study was the evaluation of the trace element contamination level in sediments of the most important rivers in Serbia and their tributaries. The determination of the aqua regia soluble contents of 12 micro- and macro-elements (Ca, Cd, Co, Cr, Cu, Fe, Mn, Pb, Ni, Zn, Be and V) in sediments was developed by the microwave digestion technique combined with inductively coupled plasma atomic emission spectrometry. Correlation analysis and principal component analysis distinguishes factors of lithogenic and anthropogenic origins. The Fe, Mn, Be and V contents are controlled by a regional lithogenic high background factor, while Cd, Cr, Pb, Ni, Zn and Cu are recognized as tracer of pollution. For Co, mixed sources from both lithogenic and anthropogenic inputs were evidenced.The investigated sediment of the major rivers and their tributaries in Serbia showed high concentrations of metals, especially of Cd, Pb, Cu and Zn, which may cause serious environmental impacts. Rivers which flow into the Danube from its entrance into Serbia significantly influence the chemical load of the water and sediments.The experimental study was conducted using two BCR standard reference materials. The calculated accuracy and precision confirmed the good performance of the adopted procedures. 相似文献
136.
Sanja Stanojevic Anne Ochsenbein Ralf Busch 《Journal of Sol-Gel Science and Technology》2013,66(3):518-525
In this study the role of different types of metal alkoxides, as well as the roles of acetyl acetone (ACAC) and polyethylene glycol (PEG) on co-continuous porosity formation in thin oxide films (TiO2, Nb2O5, SiO2 and TiO2–SiO2 mixed oxide) is investigated. The films are produced by the spin coating method and the resulting morphologies are characterized from the scanning electron microscope images of the surface and of the focused ion beam machined cross-sections. Results show that the porous, co-continuous morphology forms only in transition metal oxide films, TiO2 and Nb2O5, and that it does not form in the semimetal SiO2 film. The effect of interfacial activity of ACAC modified Ti- and Nb-alkoxides together with the effect of PEG reaction with the metal oxide oligomers are found to cause co-continuous porosity formation in TiO2 and Nb2O5 films. Moreover, it appears that both of these effects are more pronounced during formation of Nb2O5 than TiO2 films. 相似文献
137.
Hercigonja Radmila V. Vranješ-Djurić Sanja D. Mirković Marija D. Marković Bojana M. Maksin Danijela D. Marković Bojana N. Nastasović Aleksandra B. 《Journal of Radioanalytical and Nuclear Chemistry》2018,317(1):215-225
Journal of Radioanalytical and Nuclear Chemistry - The adsorption properties of two zeolite types, faujasite (NaY, ZnY, CoY) and LTA-4A zeolite (NaA, ZnA, CoA), towards technetium were studied in... 相似文献
138.
Ivo Crnolatac Iva Rogan Boris Majić Sanja Tomić Todor Deligeorgiev Gordan Horvat Damjan Makuc Janez Plavec Gennaro Pescitelli Ivo Piantanida 《Analytica chimica acta》2016
Two small molecules showed intriguing properties of analytical multipurpose probes, whereby one chromophore gives different signal for many different DNA/RNA by application of several highly sensitive spectroscopic methods. Dyes revealed pronounced fluorescence ratiomeric differentiation between ds-AU-RNA, AT-DNA and GC-DNA in approximate order 10:8:1. Particularly interesting, dyes showed specific fluorimetric response for poly rA even at 10-fold excess of any other ss-RNA, and moreover such emission selectivity is preserved in multicomponent ss-RNA mixtures. The dyes also showed specific chiral recognition of poly rU in respect to the other ss-RNA by induced CD (ICD) pattern in visible range (400–500 nm), which was attributed to the dye-side-chain contribution to binding (confirmed by absence of any ICD band for reference compound lacking side-chain). Most intriguingly, minor difference in the side-chain attached to dye chromophore resulted in opposite sign of dye-ICD pattern, whereby differences in NMR NOESY contacts and proton chemical shifts between two dye/oligo rU complexes combined with MD simulations and CD calculations attributed observed bisignate ICD to the dimeric dye aggregate within oligo rU. 相似文献
139.
Sanja Mahovic Poljacek Dubravko Risovic Tomislav Cigula Miroslav Gojo 《Journal of Solid State Electrochemistry》2012,16(3):1077-1089
The porous structure of the aluminium oxide surface of lithographic printing plate (PP) has a most significant influence on
the quality of the imprints. This study presents the results of application of electrochemical impedance spectroscopy (EIS)
in characterization of PPs' porous structures and their changes during chemical processing. Two common PP types—thermal and
conventional—were investigated. The influence of the processing solution’s working age on topographical changes of PP surface
and associated change in the impedance spectra are investigated and discussed. The equivalent electrical circuit models reproducing
the observed EIS spectra are proposed. Based on these models two mechanisms of surface’s topography changes responsible for
degradation of PP performance due to the processing are identified and discussed. 相似文献