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61.
Silvia Petrezselyova Angel Dominguez Pavla Herynkova Juan F. Macias Hana Sychrova 《Yeast (Chichester, England)》2013,30(10):395-402
Cation–chloride co‐transporters serve to transport Cl– and alkali metal cations. Whereas a large family of these exists in higher eukaryotes, yeasts only possess one cation–chloride co‐transporter, Vhc1, localized to the vacuolar membrane. In this study, the human cation–chloride co‐transporter NKCC2 complemented the phenotype of VHC1 deletion in Saccharomyces cerevisiae and its activity controlled the growth of salt‐sensitive yeast cells in the presence of high KCl, NaCl and LiCl. A S. cerevisiae mutant lacking plasma‐membrane alkali–metal cation exporters Nha1 and Ena1‐5 and the vacuolar cation–chloride co‐transporter Vhc1 is highly sensitive to increased concentrations of alkali–metal cations, and it proved to be a suitable model for characterizing the substrate specificity and transport activity of human wild‐type and mutated cation–chloride co‐transporters. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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Michaela Škodová Jan Kučka Miroslav Vetrík Jan Skopal Zuzana Walterová Ondřej Sedláček Petr Štěpánek Jana Mattová Pavla Poučková Petr Urbánek Martin Hrubý 《Reactive and Functional Polymers》2013,73(11):1426-1431
Wilson’s disease is a genetic disorder that leads to a high accumulation of copper in multiple organs with subsequent toxic effects. In this paper, a gentle therapy to eliminate harmful copper concentrations in patients with Wilson’s disease is proposed using an oral administration of insoluble polymeric sorbents containing selective chelating groups for copper(II). The sorbents contained triethylenetetramine, N,N-di(2-pyridylmethyl)amine, 8-hydroxyquinoline or 8-hydroxyquinoline-5-sulfonic acid chelating groups bound to a methacrylate-based macroporous support. Nearly quantitative copper(II) uptake within minutes was achieved in buffers modeling the pH range present in the gastric environment (pH 2.0 and 4.0). The sorbents demonstrated chelating selectivity for copper(II) against zinc(II) with ratios of up to 1321. The sorbents demonstrated sufficient stability of the copper complexes against rechelation using studies in a model environment for the small intestine (the presence of chelating amino acids, pH 6.8). 相似文献
63.
Pavla Spáčilová Petr Nauš Dr. Radek Pohl Dr. Ivan Votruba Dr. Jan Snášel Dr. Helena Zábranská Dr. Iva Pichová Dr. Ria Ameral Gabriel Birkuš Dr. Tomáš Cihlář Dr. Michal Hocek Prof. 《ChemMedChem》2010,5(8):1386-1396
A series of cycloSal‐phosphate prodrugs of a recently described new class of nucleoside cytostatics (6‐hetaryl‐7‐deazapurine ribonucleosides) was prepared. The corresponding 2′,3′‐isopropylidene 6‐chloro‐7‐deazapurine nucleosides were converted into 5‐O′‐cycloSal‐phosphates. These underwent a series of Stille or Suzuki cross‐couplings with diverse (het)arylstannanes or ‐boronic acids to yield the protected 6‐(het)aryl‐7‐deazapurine pronucleotides that were subsequently deprotected to give 12 derivatives of free pronucleotides. The in vitro cytostatic effect of the pronucleotides was compared with parent nucleoside analogues. In most cases, the activity of the pronucleotide was similar to or somewhat lower than that of the corresponding parent nucleosides, with the exception of 7‐fluoro pronucleotides 13 a , 13 b , and 13 d , which had exhibited GIC50 values that were improved by one order of magnitude (to the low nanomolar range). The presence of a cycloSal‐phosphate group also influenced selectivity toward various cell lines. Several pronucleotides were found which strongly inhibit human adenosine kinase but only weakly inhibit the MTB adenosine kinase. 相似文献
64.
Advances in the technology of astronomical spectra acquisition have resulted in an enormous amount of data available in world-wide telescope archives. It is no longer feasible to analyze them using classical approaches, so a new astronomical discipline,astroinformatics, has emerged. We describe the initial experiments in the investigation of spectral line profiles of emission line stars using machine learning with attempt to automatically identify Be and B[e] stars spectra in large archives and classify their types in an automatic manner. Due to the size of spectra collections, the dimension reduction techniques based on wavelet transformation are studied as well. The result clearly justifies that machine learning is able to distinguish different shapes of line profiles even after drastic dimension reduction. 相似文献
65.
Different approaches to superhard coatings and nanocomposites 总被引:3,自引:0,他引:3
Stan Veprek Maritza G.J. Veprek-Heijman Pavla Karvankova Jan Prochazka 《Thin solid films》2005,476(1):1-29
Different approaches to the preparation of superhard coatings such as intrinsically superhard materials, coatings whose hardness is enhanced by energetic ion bombardment during deposition, and nanostructured superhard materials are discussed with the emphasis on the question of how to distinguish between the different mechanisms of hardness enhancement in thin coatings. We compare the thermal and long-term stability in air and some further properties of such coatings. The lack of success of some workers to reproduce the high value of hardness reported by Veprek et al. is explained in terms of inappropriate choice of the deposition conditions and/or impurities. 相似文献
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Josef Balík Pavel Híc Jana Kulichová Pavla Novotná Jan Tříska Naděžda Vrchotová Jan Strohalm Danuše Lefnerová Milan Houška 《Food and Bioprocess Technology》2017,10(7):1367-1373
Red and white grape musts were enriched with 7-hydroxymatairesinol (HMR), which is the main lignan contained in spruce knots. Lignan enrichment was achieved by adding a spruce knot ethanol extract. Enriched musts were stored for 12 months and during storage must samples were periodically analyzed for HMR and alpha-conidendrin content, antioxidant activity, total polyphenols, and anti-mutagenicity. The data were statistically evaluated in order to determine the influence of grape type, quantity of added lignan extracts, addition of sugar, method of preservation and storage time on the quantity of lignans added, antioxidant activity, total polyphenols, and anti-mutagenicity. Lignan content was significantly influenced by the addition of lignan extracts. After storage, lignan content had changed only moderately and the added lignans were stable in the stored musts. Total polyphenol content and antioxidant activity of grape musts were significantly increased by the type of must grape and by thermomaceration. Thermomacerated red musts exhibited higher anti-mutagenicity compared to thermomacerated white musts, independent of lignan addition. 相似文献
68.
Eduard Brynda Milan Houska Jiří Kysilka Martin Přádný Petr Lesný Pavla Jendelová Jiří Michálek Eva Syková 《Journal of materials science. Materials in medicine》2009,20(4):909-915
Infrared attenuated total reflection spectroscopy was used for in situ observation of the deposition of collagen I on poly(2-hydroxyethyl
methacrylate-co-methacrylic acid, 2.9%) hydrogels and subsequent attachment of laminin or fibronectin on the collagen surface.
While there was no adsorption of collagen dissolved in an acid solution on the hydrogel surface, it deposited on the surface
at pH 6.5. The collagen layers with attached laminin or fibronectin were stable on hydrogel surface in physiological solution.
The modification with collagen and particularly with collagen and laminin or fibronectin allowed the adhesion and growth of
mesenchymal stromal cells and astrocytes on the hydrogel surface. 相似文献
69.
Thanks to the stability, good availability, stereoselectivity and broad substrate specificity, oligosaccharide synthesis catalyzed by glycosidases represents an elegant way to complex carbohydrate structures. Two approaches to glycosidase catalysis are presented: (i) the use of structurally modified substrates that carry various functional moieties in the molecule, and (ii) the design of mutant glycosidases void of hydrolytic activity. Products of glycosidase-catalyzed synthesis are applicable in a range of areas such as immunology, therapy of Alzheimer's or Parkinson's diseases and the synthesis of neoglycoproteins. 相似文献
70.
Lucia Machová Urdzíková Ji?í R??i?ka Michael LaBagnara Kristyna Kárová ?árka Kubinová Klára Jiráková Raj Murali Eva Syková Meena Jhanwar-Uniyal Pavla Jendelová 《International journal of molecular sciences》2014,15(7):11275-11293
Transplantation of mesenchymal stem cells (MSC) improves functional recovery in experimental models of spinal cord injury (SCI); however, the mechanisms underlying this effect are not completely understood. We investigated the effect of intrathecal implantation of human MSC on functional recovery, astrogliosis and levels of inflammatory cytokines in rats using balloon-induced spinal cord compression lesions. Transplanted cells did not survive at the lesion site of the spinal cord; however, functional recovery was enhanced in the MSC-treated group as was confirmed by the Basso, Beattie, and Bresnahan (BBB) and the flat beam test. Morphometric analysis showed a significantly higher amount of remaining white matter in the cranial part of the lesioned spinal cords. Immunohistochemical analysis of the lesions indicated the rearrangement of the glial scar in MSC-treated animals. Real-time PCR analysis revealed an increased expression of Irf5, Mrc1, Fgf2, Gap43 and Gfap. Transplantation of MSCs into a lesioned spinal cord reduced TNFα, IL-4, IL-1β, IL-2, IL-6 and IL-12 and increased the levels of MIP-1α and RANTES when compared to saline-treated controls. Intrathecal implantation of MSCs reduces the inflammatory reaction and apoptosis, improves functional recovery and modulates glial scar formation after SCI, regardless of cell survival. Therefore, repeated applications may prolong the beneficial effects induced by MSC application. 相似文献