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101.
Milica Aimovi Miroslav Zori Valtcho D. Zheljazkov Lato Pezo Ivana abarkapa Jovana Stankovi Jeremi Mirjana Cvetkovi 《Molecules (Basel, Switzerland)》2020,25(22)
The objective of this study was to evaluate wild growing Satureja kitaibelii, Thymus serpyllum, Origanum vulgare, Achillea millefolium and Achillea clypeolata with respect to their essential oil (EO) content, composition and antimicrobial activity. The five species were collected at Mt. Rtanj and the village of Sesalac, Eastern Serbia. The main EO constituents of Lamiaceae plants were p-cymene (24.4%), geraniol (63.4%) and germacrene D (21.5%) in Satureja kitaibelii, Thymus serpyllum and Origanum vulgare ssp. vulgare, respectively. A. millefolium EO had multiple constituents with major ones being camphor (9.8%), caryophyllene oxide (6.5%), terpinen-4-ol (6.3%) and 1,8-cineole (5.6%), while the main EO constituents of A. clypeolata were 1,8-cineole (45.1%) and camphor (18.2%). Antimicrobial testing of the EO showed that Staphylococcus aureus (Gram-positive) was more sensitive to all of the tested EOs than Escherichia coli (Gram-negative). S. kitaibelii EO showed the highest antimicrobial activity against both tested bacterial strains. This is the first study to characterize the EO composition and antimicrobial activity of these five medicinal species from Eastern Serbia in comparison with comprehensive literature data. The results can be utilized by the perfumery, cosmetics, food and pharmaceutical industries, but also for healing purposes in self-medication. 相似文献
102.
Sonja M. Jakovetić Branimir Z. Jugović Milica M. Gvozdenović Dejan I. Bezbradica Mirjana G. Antov Dušan Ž. Mijin Zorica D. Knežević-Jugović 《Applied biochemistry and biotechnology》2013,170(7):1560-1573
Immobilized lipase from Candida antarctica (Novozyme 435) was tested for the synthesis of various phenolic acid esters (ethyl and n-butyl cinnamate, ethyl p-coumarate and n-butyl p-methoxycinnamate). The second-order kinetic model was used to mathematically describe the reaction kinetics and to compare present processes quantitatively. It was found that the model agreed well with the experimental data. Further, the effect of alcohol type on the esterification of cinnamic acid was investigated. The immobilized lipase showed more ability to catalyze the synthesis of butyl cinnamate. Therefore, the process was optimized for the synthesis of butyl cinnamate as a function of solvent polarity (logP) and amount of biocatalyst. The highest ester yield of 60.7 % was obtained for the highest enzyme concentration tested (3 % w/w), but the productivity was for 34 % lower than the corresponding value obtained for the enzyme concentration of 1 % (w/w). The synthesized esters were purified, identified, and screened for antioxidant activities. Both DPPH assay and cyclic voltammetry measurement have shown that cinnamic acid esters have better antioxidant properties than cinnamic acid itself. 相似文献
103.
Sergey A. Borodkin Leonid D. Popov Milica R. Milenković Igor N. Shcherbakov Vladimir V. Lukov 《Phosphorus, sulfur, and silicon and the related elements》2018,193(6):375-381
The Schiff base (HLBr), containing a chelating unit and triphenylphosphonium moiety has been synthesized in the reaction of 4-aminobenzyl(triphenyl)phosphonium bromide with 5-hydroxy-3-methyl-1-phenyl-4-formylpyrazole. The composition and structure of HLBr have been determined by elemental analysis, IR, 1D and 2D NMR, electronic spectroscopy and mass spectrometry. Density functional theory (DFT) calculations (6-311G(d,p) level of theory) have been carried out to investigate tautomeric forms of HL+ and the reaction mechanism of its formation and spectral properties. The most stable form in the solid state and in DMSO solution is pyrazolone (keto-amine) tautomeric form. 相似文献
104.
Replacement of calcium with europium in the phases Ca21Ni2Zn36 and CaNi2Zn3 was attempted to explore the possibility of substitution in metal flux reactions and potential magnetic interactions between closely spaced Eu2+ ions. Limited substitution occurs when Eu is added to the reaction of nickel in a Ca/Zn flux mixture, up to stoichiometries of Eu5.8(3)Ca15.2(3)Ni2Zn36 and Eu0.42(8)Ca0.58(8)Ni2Zn3. Structural characterization and magnetic susceptibility studies on EuxCa21−xNi2Zn36 phases indicate that the Eu and Ca ions do not form an even solid solution on their sites, but instead segregate in separate regions of the crystals. The europium-rich regions of the samples order ferromagnetically, with TC dependent on the size of the clusters. If the concentration of Eu in the flux is raised above 20 mol%, a new compound Eu1.63(1)Ca1.37(1)Ni2Zn3 (Cmcm, a=4.1150(5) Å, b=16.948(2) Å, c=10.302(1) Å, Z=4, R1=0.0396) is produced. 相似文献
105.
Goran Stojanovic Mirjana Damnjanovic Vladan Desnica Ljiljana Zivanov Ramesh Raghavendra Pat Bellew Neil Mcloughlin 《Journal of magnetism and magnetic materials》2006
This paper describes the design, modeling, simulation and fabrication of zig-zag and meander inductors embedded in low- or high-permeability soft ferrite material. These microinductors have been developed with ceramic coprocessing technology. We compare the electrical properties of zig-zag and meander inductors structures installed as surface-mount devices. The equivalent model of the new structures is presented, suitable for design, circuit simulations and for prediction of the performance of proposed inductors. The relatively high impedance values allow these microinductors to be used in high-frequency suppressors. The components were tested in the frequency range of 1 MHz–3 GHz using an Agilent 4287A RF LCR meter. The measurements confirm the validity of the analytical model. 相似文献
106.
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108.
Slobodan M. Radošević Milan R. PantićMilica V. Pavkov-Hrvojević Darko V. Kapor 《Annals of Physics》2013
We present the perturbation theory for lattice magnon fields of the D-dimensional O(3) Heisenberg ferromagnet. The effective Hamiltonian for the lattice magnon fields is obtained starting from the effective Lagrangian, with two dominant contributions that describe magnon–magnon interactions identified as a usual gradient term for the unit vector field and a part originating in the Wess–Zumino–Witten term of the effective Lagrangian. Feynman diagrams for lattice scalar fields with derivative couplings are introduced, on the basis of which we investigate the influence of magnon–magnon interactions on magnon self-energy and ferromagnet free energy. We also comment appearance of spurious terms in low-temperature series for the free energy by examining magnon–magnon interactions and internal symmetry of the effective Hamiltonian (Lagrangian). 相似文献
109.
JPC – Journal of Planar Chromatography – Modern TLC - The quantitative structure-retention relationship (QSRR) study has been performed in order to investigate the retention behavior of... 相似文献
110.