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121.
Mirta Rub
i Ivica ?ilovi Marina Cindri Dubravka Matkovi‐alogovi 《Acta Crystallographica. Section C, Structural Chemistry》2008,64(10):o570-o573
The molecular structures of two salicylaldehyde thiosemicarbazone derivatives, namely salicylaldehyde 4‐phenylthiosemicarbazone, C14H13N3OS, (I), and 4‐methoxysalicylaldehyde 4‐phenylthiosemicarbazone, C15H15N3O2S, (II), both of potential pharmacological interest, are found in the keto (thione) tautomeric form. The first compound represents a second triclinic polymorph of composition β‐C14H13N3OS. Although both polymorphs crystallize in the same space group (P), the α‐polymorph [Seena, Kurup & Suresh (2008). J. Chem. Crystallogr. 38 , 93–96] differs from the β form in its unit‐cell volume at 293 K. The molecules in the crystal structures of (I) and (II) are linked into centrosymmetric R22(8) dimers by hydrogen bonds of the N—H...S=C type. These dimers are connected through π–π stacking and T‐shaped C—H...π interactions into three‐dimensional networks. 相似文献
122.
N. Neskovic S. Petrovic L. Zivkovic 《The European Physical Journal B - Condensed Matter and Complex Systems》2000,18(4):553-558
This study is devoted to the transmission of Ne10+ ions through a Si thin crystal. The ion energy is 60 MeV and the crystal thickness is varied from 159 to 478 atomic layers, i.e. within the first rainbow cycle. The analysis is performed by the theory of crystal rainbows. The angular distribution of
the transmitted ions is generated by the computer simulation method. Then, the rainbow lines in the scattering angle plane
are determined. These lines ensure the full explanation of the angular distribution.
Received 11 May 2000 相似文献
123.
Momcilovic Milos Zivkovic Sanja Kuzmanovic Miroslav Ciganovic Jovan Rankovic Dragan Trtica Milan Savovic Jelena 《Plasma Chemistry and Plasma Processing》2019,39(4):985-1000
Plasma Chemistry and Plasma Processing - Time-integrated optical emission spectroscopy was applied for the analysis of emission spectra, and determination of electron densities and excitation... 相似文献
124.
Bisera Stepanovska Tanturovska Aleksandra Zivkovic Faik Imeri Thomas Homann Burkhard Kleuser Holger Stark Andrea Huwiler 《Molecules (Basel, Switzerland)》2021,26(17)
Sphingosine 1-phosphate (S1P) is an extensively studied signaling molecule that contributes to cell proliferation, survival, migration and other functions through binding to specific S1P receptors. The cycle of S1P1 internalization upon S1P binding and recycling to the cell surface when local S1P concentrations are low drives T cell trafficking. S1P1 modulators, such as fingolimod, disrupt this recycling by inducing persistent S1P1 internalization and receptor degradation, which results in blocked egress of T cells from the secondary lymphoid tissues. The approval of these compounds for the treatment of multiple sclerosis has placed the development of S1PR modulators in the focus of pharmacological research, mostly for autoimmune indications. Here, we report on a novel anellated bismorpholino derivative of oxy-fingolimod, named ST-2191, which exerts selective S1P1 agonist and functional antagonist potency. ST-2191 is also effective in reducing the lymphocyte number in mice, and this effect is not dependent on phosphorylation by sphingosine kinase 2 for activity. These data show that ST-2191 is a novel S1P1 modulator, but further experiments are needed to analyze the therapeutic impact of ST-2191 in animal models of autoimmune diseases. 相似文献
125.
Kopriva I 《Optics letters》2005,30(23):3135-3137
Single-frame multichannel blind deconvolution is formulated by applying a bank of Gabor filters to a blurred image. The key observation is that spatially oriented Gabor filters produce sparse images and that a multichannel version of the observed image can be represented as a product of an unknown nonnegative sparse mixing vector and an unknown nonnegative source image. Therefore a blind-deconvolution problem is formulated as a nonnegative matrix factorization problem with a sparseness constraint. No a priori knowledge about the blurring kernel or the original image is required. The good experimental results demonstrate the viability of the proposed concept. 相似文献
126.
Glisic S. Strinic A.I. Zivkovic J.V. Petrovic Z.L. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1998,26(5):1492-1497
Volt-ampere characteristics of a hollow-cathode, hollow-anode discharge in hydrogen were measured by using a very fast di/dt probe. The large bandwidth of the probe enabled us to observe fast oscillations occurring at the onset of the current pulse and also at the moment of its quenching. Three different modes of operation are observed, the first with smooth voltage and current waveforms. The second mode occurs for voltages higher than 1500 V and is characterized by strong oscillations and the occurrence of current quenching. The third, mode occurs with a sharp transition and in it the current rises more rapidly to a much higher maximum value, while the oscillations are less pronounced. This mode has identical characteristics with the superdense glow mode of pseudospark discharges. At the point of transition a sudden change in the frequency of oscillations, of the impedance, and of the maximum transmitted power occur. Current quenching is observed in the second and in the third mode. The development of the superdense glow changes the character of the waveforms and current quenching while the mechanism leading to the superdense glow may be associated with the available voltage 相似文献
127.
128.
Aleksandar G. Savi Suzana Zivkovi Katarina K. Jovanovi Ludovic Duponchel Ivica Kopriva 《Journal of Chemometrics》2015,29(10):521-527
Proper determination of tissues is one of the challenging problems in modern medicine and histology. Currently, interpretation of the results mainly depends on the experience of a histologist, leading to high percentage of results misinterpretation. Bearing in mind potential application, we proposed the set of procedures that allow us to obtain precise, mathematically determined parameters for tissue discrimination. First, the method was tested on simulated set of images and compared with several other algorithms. As the set of experimentally obtained input data, auto‐fluorescence images of needle cross sections (Picea omorika) and stamens of common centaury (Centaurium erythraea) were used. Determination of cell types is based on inherent features of plant cells – auto‐fluorescence. As each cell type consists of various fluorescent components in different quantities for each type of tissue, its integral emission spectrum can be used as the fingerprint for identification. Cross sections were imaged using four sets of filters for detection of fluorescence (both excitation and emission). Such filter set is standard equipment for most fluorescence microscopes. One additional image was transmission image using the same optics. By applying ℓ0‐norm‐constrained nonnegative matrix factorization in a space induced by explicit feature maps, it is possible to identify up to 11 tissues in needles and five in stamens (actual number of tissues). In comparison to other image analysis methods, the greatest advantage is the fact that the number of extracted components significantly exceeds the number of initial images while most other techniques can extract only as much components as the number of initial images. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
129.
Bezić N Vuko E Dunkić V Ruščić M Blažević I Burčul F 《Molecules (Basel, Switzerland)》2011,16(9):8119-8129
The purpose of this study was to compare the essential oil profiles of four Croatian Teucrium species (Lamiaceae), as determined by GC and GC/MS, with their antiphytoviral efficiency. A phytochemical analysis showed that T. polium, T. flavum, T. montanum and T. chamaedrys are characterized by similar essential oil compositions. The investigated oils are characterized by a high proportion of the sesquiterpene hydrocarbons β-caryophyllene (7.1-52.0%) and germacrene D (8.7-17.0%). Other important components were β-pinene from T. montanum and α-pinene from T. flavum. The investigated essential oils were proved to reduce lesion number in the local host Chenopodium quinoa Willd. infected with Cucumber Mosaic Virus (CMV), with reductions of 41.4%, 22.9%, 44.3% and 25.7%, respectively. 相似文献
130.
The study reported here shows a practicable preparation of pure atenolol enantiomers using enantioselective liquid chromatography. The successful separation of enantiomers of the final atenolol and the intermediate ester and the good peak shapes could not have been obtained without diethylamine as a component of the mobile phase. That makes difficult the recycling of the three-component mobile phase, an unavoidable step in simulated moving bed chromatography separation technology. The only suitable methodology for preparation of atenolol enantiomers proved to be synthesis from its N-benzyl-N-isopropyl precursor and the chiral stationary phase Chiralpak AD was found to be very convenient for preparative separation of these enantiomers. The enantiomeric purities and recovery of separated enantiomers of this N-benzyl-N-isopropyl precursor were very high, allowing high enantiomeric purities of the final products, ee's 99.3% for S- and 99.0% for R-atenolol. The chromatographic separation parameters, as well as solubility of racemate in the mobile phase, are good bases for the further examination of possible scale-up resolution of compound 6. 相似文献