No (3074)
Number of found documents:
3074
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Effect of metal sensitizers on photochemical vapor generation of bismuth for analytical atomic spectrometry
Vyhnanovský, Jaromír; Yildiz, D.; Musil, Stanislav
2019 - English
Three new sensitizers with a significant positive effect on the photochemical vapor generation of bismuth were described. Cobalt was found to be the most effective and led to a significant enhancement of the signal.
Keywords:
photochemical volatile species generation; bismuth; AAS
Available at various institutes of the ASCR
Effect of metal sensitizers on photochemical vapor generation of bismuth for analytical atomic spectrometry
Three new sensitizers with a significant positive effect on the photochemical vapor generation of bismuth were described. Cobalt was found to be the most effective and led to a significant enhancement ...
Adhesion and growth of adipose tissue-derived stem cells on fibrin assemblies with attached growth factors for tissue engineering of heart valves
Filová, Elena; Trávníčková, Martina; Knitlová, Jarmila; Matějka, Roman; Kučerová, Johanka; Riedelová, Zuzana; Brynda, Eduard; Bačáková, Lucie
2019 - English
Currently used xenogeneic biological heart valve prostheses are decellularized and crosslinked with glutaraldehyde. These grafts usually undergo degeneration and calcification. Pericardium-based heart valve prostheses, re-seeded with autologous cells, i.e. Adipose tissue-derived cells (ASCs) and endothelial cells, could have longer durability and biocompatibility. In order to improve the adhesion of cells and their ingrowth into decellularized pericardium, various fibrin (Fb) layers were developed, i.e. Fb, Fb with covalently bound heparin (H), Fb with either vascular endothelial growth factor (VEGF) or fibroblast growth factor 2 (FGF) in various concentrations (1 ng/ml, 10 ng/ml, 100 ng/ml) or with both VEGF and FGF (100 ng/ml). Growth factors were attached onto Fb via heparin or were adsorbed. ASCs were seeded on theses layers in a DMEM medium supplemented with 2 % of fetal bovine serum, TGFβ1 and BMP-4 (both 2.5 ng/ml), and with ascorbic acid. Cell adhesion and growth/viability was assessed by counted cell number/MTS evaluation. ASCs were stained for differentiation markers of smooth muscle cells, such as alpha-actin, calponin, and myosin heavy chain. On day 7, ASCs on Fb-H-VEGF layers produced both calponin and alpha-actin. An increased FGF concentration caused reduced calponin staining of ASCs. Lack of heparin in fibrin assemblies with growth factors inhibited the production of both alpha-actin and calponin in ASCs. The highest ASCs density/viability was found on Fb-H-VEGF-FGF layer. The proper formulation of fibrin coatings could be favorable for ASCs growth and differentiation and could subsequently support endothelialization of cardiovascular prostheses with endothelial cells.
Keywords:
adipose tissue-derived stem cells; fibrin assemblies; growth factors; heart valves
Available at various institutes of the ASCR
Adhesion and growth of adipose tissue-derived stem cells on fibrin assemblies with attached growth factors for tissue engineering of heart valves
Currently used xenogeneic biological heart valve prostheses are decellularized and crosslinked with glutaraldehyde. These grafts usually undergo degeneration and calcification. Pericardium-based heart ...
Purification of water soluble bioactive polysaccharides from biomass of heterotrophic mutant alga Chlorella vulgaris G11.
Sushytskyi, L.; Lukáč, Pavol; Bleha, R.; Čopíková, J.; Vannucci, Luca; Sinica, A.; Kaštánek, P.
2019 - English
Water extract obtained from biomass of mutant alga Chlorella vulgaris G11 was deproteinized and then purified with AEC on DEAE Sepharose FF and SEC on Sepaphadex G-75 superfine columns. Two high MW (>1000 kDa and 98,3 kDa) polysaccharides (CPS1 and CPS3) were eluted with water and 0.5M NaCl on DEAE column, and heteropolysaccharide with MW of 15 kDa (CPS2) was also eluted with water on DEAE. The former fractions were identified as branched rhamnans, the latter one as branched xylogalactofuranan of unusual structure. CPS1 shown properties of unstable polimer: according to GPC analysis and by using light scattering and RI detectors it was found, that some fraction of polymers (260-800 kDa) have self-assembling properties in aqueous solution, and MW of this fraction decreased during some time while polimer with initially bigger MW (>1000 kDa) became bigger. CPS3 was eluted with 0.3-0.5 M of NaCl on DEAE Sepharose FF column and have MW of 98,3 kDa. Cell toxicity of the products were tested in vitro on cell cultures for different concentrations
Keywords:
Mutant alga; Chlorella vulgaris G11; chromatography; polymer; cell cultures
Available at various institutes of the ASCR
Purification of water soluble bioactive polysaccharides from biomass of heterotrophic mutant alga Chlorella vulgaris G11.
Water extract obtained from biomass of mutant alga Chlorella vulgaris G11 was deproteinized and then purified with AEC on DEAE Sepharose FF and SEC on Sepaphadex G-75 superfine columns. Two high MW ...
Metals in atmospheric particulate matter
Barboříková, H.; Mikuška, Pavel; Hegrová, J.; Pokorná, Petra; Krajčovič, J.
2019 - English
Atmospheric pollution is one of the most serious global enviroment problem. Metals constitute important class of pollutants which have received athe attention of researchers all over the world. Metals have strong potential to be adsorbed on particulate matter and than enter the human body through inhalation causing several health issue (asthma, lung cancer).
Keywords:
aerosol; metals
Available at various institutes of the ASCR
Metals in atmospheric particulate matter
Atmospheric pollution is one of the most serious global enviroment problem. Metals constitute important class of pollutants which have received athe attention of researchers all over the world. Metals ...
Structural characterization of fatty acids with triple bond and unusual double bond positions by HPLC/APCI-MS2
Horká, Petra; Vrkoslav, Vladimír; Cvačka, Josef
2019 - English
Fatty acid methyl esters (FAMEs) were analyzed by reversed-phase HPLC coupled to atmospheric pressure chemical ionization (APCI) mass spectrometry. Acetonitrile was used as mobile phase. The gas-phase reactions of acetonitrile and unsaturated FAMEs in the APCI source provided [M + C3H5N]+• adducts. Subsequent MS/MS analysis of these ions gave diagnostic fragments. The formation and fragmentation of the acetonitrile-related adducts were utilized for the structural characterization of FAME with isolated double bonds in (Z)-9,19-hexacosadienoic acid methyl ester, FAME with conjugated double bonds in (Z)-9,11-octadecadienoic acid methyl ester and FAME with a triple bond in 9-octadecynoic acid methyl ester.
Keywords:
acetonitrile-related adducts; acetylenic lipids; multiple bond localization; mass spectrometry
Available at various institutes of the ASCR
Structural characterization of fatty acids with triple bond and unusual double bond positions by HPLC/APCI-MS2
Fatty acid methyl esters (FAMEs) were analyzed by reversed-phase HPLC coupled to atmospheric pressure chemical ionization (APCI) mass spectrometry. Acetonitrile was used as mobile phase. The gas-phase ...
Charge Transport in Single Oligophenylene Molecular Wires with Different Anchoring Groups
Hromadová, Magdaléna; Kolivoška, Viliam; Šebera, Jakub; Sebechlebská, Táňa; Gasior, Jindřich; Nováková Lachmanová, Štěpánka; Mészáros, G.; Lindner, M.; Mayor, M.; Valášek, M.
2019 - English
This work compares single molecule conductance measurements of selected organic systems containing identical oligophenylene molecular wires and different tripodal anchoring groups. Single molecule conductance G was obtained by a scanning tunneling microscopy break junction technique complemented by theoretical calculations based on the density functional theory and non-equilibrium Green’s function formalism. Two molecules were compared where the same oligophenylene wire is connected to one of the electrodes via a tripod substituted on each leg by a thiol group either in the meta or para position. By combined experimental and theoretical analysis it was possible to confirm that single molecule conductance in the metal-molecule-metal junction of both molecules corresponds to a fully extended molecular wire, which is attached to one of the electrodes by all three thiolate bonds of the tripod. Experimental results confirmed that G value of meta-connected molecules is lower than that of para, whereas junction formation probability was higher for meta functionalization.
Keywords:
STM break junction; Tetraphenylmethane Tripodal anchor; Single molecule conductance
Available at various institutes of the ASCR
Charge Transport in Single Oligophenylene Molecular Wires with Different Anchoring Groups
This work compares single molecule conductance measurements of selected organic systems containing identical oligophenylene molecular wires and different tripodal anchoring groups. Single molecule ...
The Effect of temperature treatment TiO2 nanoparticles on antibacterial properties
Bytesnikova, Z.; Valeckova, V.; Švec, P.; Richtera, L.; Šmerková, K.; Vítek, Petr; Adam, V.
2019 - English
The synthesis of TiO2 nanoparticles (NPs) under various temperature treatments was described and TiO2 NPs was subsequently tested as an antibacterial agent. Scanning electron microscopy (SEM), Raman spectroscopy, Dynamic light scattering (DLS) were used to confirm structure of TiO2 NPs and detect differences between individual batches treated with different temperature. Antibacterial properties were tested on Escherichia coli (E. coli). TiO2 NPs as photocatalyst was incubated with bacterial cells under ambient light. Changes in temperature treatment can affect diameter size and crystal structure of TiO2 NPs as well as its antibacterial properties.
Keywords:
water; Titanium dioxide; pathogenic bacteria; nanoparticles; antibacterial properties; E.coli; nanomaterial
Available at various institutes of the ASCR
The Effect of temperature treatment TiO2 nanoparticles on antibacterial properties
The synthesis of TiO2 nanoparticles (NPs) under various temperature treatments was described and TiO2 NPs was subsequently tested as an antibacterial agent. Scanning electron microscopy (SEM), Raman ...
Charge Transport in Single Oligophenylene Molecular Wires with Different Anchoring Groups
Hromadová, Magdaléna; Kolivoška, Viliam; Šebera, Jakub; Sebechlebská, Táňa; Gasior, Jindřich; Nováková Lachmanová, Štěpánka; Mészáros, G.; Lindner, M.; Mayor, M.; Valášek, M.
2019 - English
This work compares single molecule conductance measurements of selected organic systems containing identical oligophenylene molecular wires and different tripodal anchoring groups. Single molecule conductance G was obtained by a scanning tunneling microscopy break junction technique complemented by theoretical calculations based on the density functional theory and non-equilibrium Green’s function formalism. Two molecules were compared where the same oligophenylene wire is connected to one of the electrodes via a tripod substituted on each leg by a thiol group either in the meta or para position. By combined experimental and theoretical analysis it was possible to confirm that single molecule conductance in the metal-molecule-metal junction of both molecules corresponds to a fully extended molecular wire, which is attached to one of the electrodes by all three thiolate bonds of the tripod. Experimental results confirmed that G value of meta-connected molecules is lower than that of para, whereas junction formation probability was higher for meta functionalization.
Keywords:
STM break junction; Tetraphenylmethane Tripodal anchor; Single molecule conductance
Available on request at various institutes of the ASCR
Charge Transport in Single Oligophenylene Molecular Wires with Different Anchoring Groups
This work compares single molecule conductance measurements of selected organic systems containing identical oligophenylene molecular wires and different tripodal anchoring groups. Single molecule ...
Electrochemical Enzymatic Biosensors for Determination of Catecholamines in Flow Systems
Josypčuk, Bohdan; Barek, J.; Josypčuk, Oksana
2019 - English
Several biosensors (BS) based on flow enzymatic mini-reactors containing a mesoporous silica powder covered by enzyme laccase or tyrosinase were used for determination of L-DOPA, dopamine, noradrenaline, and adrenaline. The silica powder of MCM-41 with covalently bonded laccase was found to be the best reactor filling for the detection of catecholamines. Relative current response of such BS was 100 % for dopamine, 32.1 % for L-DOPA, 26.2 % for noradrenaline, and 0.71 % for adrenaline. The practical applicability of Lac-MCM41 biosensor was successfully verified by the determination of dopamine and noradrenaline in medical solutions for infusions.
Keywords:
Enzymatic biosensor; Catecholamines; Flow analysis
Available on request at various institutes of the ASCR
Electrochemical Enzymatic Biosensors for Determination of Catecholamines in Flow Systems
Several biosensors (BS) based on flow enzymatic mini-reactors containing a mesoporous silica powder covered by enzyme laccase or tyrosinase were used for determination of L-DOPA, dopamine, ...
ACTRIS IMP – ÚČAST ČESKÉ REPUBLIKY V NÁRODNÍCH VÝZKUMNÝCH INFRASTRUKTURÁCH A TÉMATICKÝCH CENTRECH ACTRIS
Ondráček, Jakub; Váňa, M.; Klánová, J.; Holoubek, Ivan; Ždímal, V.
2019 - English
ACTRIS (The Aerosol, Clouds and Trace Gases Research Infrastructure) je panevropskou výzkumnou infrastrukturou, jejímž hlavním cílem je tvorba vysoce kvalitních dat a podávání informací o krátkodobých složkách atmosféry a o procesech vedoucích ke změnám těchto složek v přírodním a kontrolovaném laboratorním prostředí. ACTRIS je dlouhodobou aktivitou (již od roku 2012, viz. Obr. 1) více než 100 partnerských organizací po celé Evropě, jejichž cílem je integrace, harmonizace a distribuce vysoce kvalitních vědeckých výstupů poskytovaných nejlepšími pracovišti atmosférického výzkumu v (prozatím) 22 evropských zemích. ACTRIS je logickým pokračováním 15-tiletého rozvoje velkých výzkumných infrastruktur financovaného členskými státy a evropskou komisí (EC) prostřednictvím programu výzkumných infrastruktur (Research Infrastructure programme) zahrnujících např. Projekty EARLINET, EUSAAR, CREATE a CLOUDNET.
Available at various institutes of the ASCR
ACTRIS IMP – ÚČAST ČESKÉ REPUBLIKY V NÁRODNÍCH VÝZKUMNÝCH INFRASTRUKTURÁCH A TÉMATICKÝCH CENTRECH ACTRIS
ACTRIS (The Aerosol, Clouds and Trace Gases Research Infrastructure) je panevropskou výzkumnou infrastrukturou, jejímž hlavním cílem je tvorba vysoce kvalitních dat a podávání informací o krátkodobých ...
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