No (5624)
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Voltametrické stanovení pálivosti chilli paprik na elektrodě ze skelného uhlíku modifikované fosfolipidy
Skopalová, J.; Rajcová, A.; Vokounová, D.; Navrátil, Tomáš
2019 - Czech
Kapsaicin je přírodní alkaloid vyskytující se v plodech chilli paprik, které patří k nejdůležitějším a nejrozšířenějším kořením. Za jejich popularitou stojí významné organoleptické vlastnosti (typická pálivá chuť), antioxidační či antimikrobiální účinky. Pálivost chilli paprik je hlavním důvodem jejich konzumace a z pohledu konzumenta představuje jednu z jejich nejdůležitějších charakteristik. Od toho se proto odvozuje potřeba tuto charakteristiku kvantifikovat. Míra pálivosti přímo souvisí s obsahem kapsaicinu a jemu podobných látek (kapsaicinoidů) v paprikách. Kromě potravinářství nachází kapsaicin své užití i v lesnictví (zemědělství) jako ochrana před okusem stromů zvěří. The aim of this study was to develop a simple method for evaluation of the pungency in chili peppers with a glassy carbon electrode modified using phospholipid membrane prepared from asolectin. For these purposes cyclic voltammetry (CV) and differential pulse voltammetry (DPV) have been used. A few different methods have been tested: direct method, transfer method on unmodified and modified electrode, using standard addition method as well as calibration curve method. A statistically significant correlations with the results of the reference HPLC method have been found in case of voltammetric methods, especially in DPV with asolectin modified electrode.
Keywords:
capsaicin; voltammetry; glassy carbon electrode
Available on request at various institutes of the ASCR
Voltametrické stanovení pálivosti chilli paprik na elektrodě ze skelného uhlíku modifikované fosfolipidy
Kapsaicin je přírodní alkaloid vyskytující se v plodech chilli paprik, které patří k nejdůležitějším a nejrozšířenějším kořením. Za jejich popularitou stojí významné organoleptické vlastnosti (typická ...
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 ...
Lokalizace poloh dvojných a trojných vazeb u methylesterů mastných kyselin pomocí HPLC/APCI-MS2
Horká, Petra; Vrkoslav, Vladimír; Cvačka, Josef
2019 - Czech
Poloha a počet dvojných vazeb v alifatickém řetězci ovlivňuje fyzikální, chemické a biologické vlastnosti lipidů, avšak jednoznačné určení poloh těchto násobných vazeb je problematické. V roce 2012 byla publikována metoda kapalinové chromatografie s chemickou ionizací za atmosférického tlaku s hmotnostní detekcí (HPLC/APCI-MS) [1] vhodná pro analýzu polohy dvojných vazeb využívající tvorby molekulových aduktů [M + C3H5N]+. při APCI za přítomnosti acetonitrilu. Methylestery mastných kyselin (FAMEs) byly analyzovány HPLC/APCI-MS2 se 100% acetonitrilem jako mobilní fází. Při APCI docházelo v plynné fázi k tvorbě reaktivních částic, vznikajících ze složek mobilní fáze, které se vázaly na násobné vazby v alifatickém řetězci FAMEs za vzniku aduktu [M + C3H5N]+.. Kolizně indukovanou disociací (CID) aduktu [M + C3H5N]+., se získaly diagnostické fragmenty určující polohu (polohy) násobných vazeb. Zmíněná metoda byla evaluována pro běžně analyzované polynenasycené FAMEs s tradiční polohu dvojných vazeb (methylene-interrupted).
Keywords:
acetonitrile-related adducts; multiple bond localization
Available at various institutes of the ASCR
Lokalizace poloh dvojných a trojných vazeb u methylesterů mastných kyselin pomocí HPLC/APCI-MS2
Poloha a počet dvojných vazeb v alifatickém řetězci ovlivňuje fyzikální, chemické a biologické vlastnosti lipidů, avšak jednoznačné určení poloh těchto násobných vazeb je problematické. V roce 2012 ...
Experimentální metody studia aerosolových nanočástic.
Ždímal, Vladimír; Schwarz, Jaroslav; Ondráčková, Lucie; Ondráček, Jakub
2019 - Czech
V novém miléniu enormně vzrostly experimentální možnosti studia aerosolových částic. Nejen, že je možné určit rozdělení velikosti částic v různých metrikách, nejen, že lze určit velikostně rozlišené chemické složení, ale byly vyvinuty metody, které umožňují, aby všechny tyto úlohy byly řešeny naráz v reálném čase. Tyto metody vycházejí z několika základních fyzikálních principů: molekulární difúze založené na Brownově pohybu, elektrostatické separace definovaně nabitých částic, kondenzačního růstu částic, gravitačního usazování, urychlení částic v tryskách, setrvačné impakce a rozptylu světla na částicích.\nPokud bychom se však specificky zajímali o separaci částic o průměru menším než 100 nanometrů, výběr experimentálních metod by se podstatně snížil. Ve skutečnosti máme pouze čtyři fyzikální principy, které lze použít v tomto rozsahu velikostí s rozumnou mírou nejistoty: Brownův pohyb, elektrostatiku, impakci a kondenzaci. Pro stanovení chemického složení v daném rozmezí velikostí je nejběžněji používaná kombinace fyzikálně-chemické ionizace s hmotnostní spektrometrií, avšak rozsah kvantifikovatelných látek je značně omezen.\nV poslední době je stále důležitější sledovat expozici pracovníků aerosolovým nanočásticím. Úloha je komplikována skutečností, že pro stanovení osobní expozice je nutné odebrat vzorky přímo z respirační zóny pracovníka. Pro tuto úlohu dosud není velký výběr možností a experimentální metody se stále vyvíjejí a testují. Slibnou alternativou je stacionární měření, kde jsou nejmodernější aerosolové spektrometry umístěny v blízkosti pracovního prostoru, a z jejich údajů lze skutečnou expozici pracovníka odhadnout. Pro kvantifikaci expozice je však vhodné kalibrovat on-line přístroje srovnáním se současným osobním odběrem.\n During the last few decades, the experimental possibilities of studying aerosol particles have grown enormously. Not only is it possible to determine the particle size distribution in different metrics, not only can the chemical composition of the size-resolved aerosol be determined, but methods have been developed over the last two decades that allow all of these tasks to be handled in real time. These methods stem from several basic physical principles: molecular diffusion based on Brownian motion, electrostatic separation of particles with predictable charge, condensational growth of particles, gravitational settling, acceleration of particles in nozzles, inertial impaction, and light scattering on particles.\nHowever, if we are specifically interested in separating particles smaller than 100 nanometers in diameter, the choice of experimental methods would be substantially reduced. In fact, we have only four physical principles that can be utilized in this size range with reasonable degree of uncertainty: Brownian motion, electrostatics, impaction and condensation. For the determination of the chemical composition in a given size range, the most commonly used is a combination of physical / chemical ionization with mass detection, however, the range of quantifiable substances is greatly limited.\nRecently, exposure monitoring of workers in the production of engineered nanoparticles has become increasingly important. Here, the task is further complicated by the fact that it is necessary to sample directly from the vicinity of the worker's mouth to determine personal exposure. As far as the collection of nanoparticles in the respiratory zone is concerned, there is not yet a great choice of options, and experimental methods are still being developed and tested. A promising alternative is a stationary measurement, where state-of-the-art aerosol spectrometers are located close to the working space of the personnel, so that the actual exposure of the worker can be estimated. In this case, however, it is necessary to calibrate the on-line instruments by comparison with simultaneous personal collection.\n
Keywords:
aerosol; experimental methods; nanoparticles
Available at various institutes of the ASCR
Experimentální metody studia aerosolových nanočástic.
V novém miléniu enormně vzrostly experimentální možnosti studia aerosolových částic. Nejen, že je možné určit rozdělení velikosti částic v různých metrikách, nejen, že lze určit velikostně rozlišené ...
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 ...
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