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Mikroplasty a jejich odstraňování z vod pomocí sorbentů.
Spáčilová, Markéta; Dytrych, Pavel; Krejčíková, Simona; Fajgar, Radek; Šolcová, Olga
2020 - Czech
Zvýšený výskyt cizorodých látek ve vodních zdrojích, ať už mikroplastů či dalších jiných organických kontaminantů je v současné době stále se zvyšující environmentální problém. Tato problematika úzce souvisí se zmapováním jejich výskytu ve vodním prostředí, a dále také s možnými způsoby jejich odstranění. V rámci práce byla nejprve provedena charakterizace připravených mikroplastových částic pěti nejčastěji používaných plastů (polyethylen, polyamid, polytetrafluorethylen, polyethylenglykoltereftalát a polystyren) pomocí skenovací elektronové mikroskopie (SEM), Ramanovy spektroskopie a infračervené spektroskopie (IČ). Tyto mikroplastové částice byly použity pro přípravu simulovaných vod kontaminovaných mikroplasty. Připravené simulované vzorky vod kontaminovaných mikroplasty byly využity pro vývoj metodiky určení počtu obsažených částic mikroplastů. Dále byly testovány možnosti odstranění mikroplastů ze vzorků pomocí sorbentů na bázi přírodních bentonitů a zeolitů. Bylo potvrzeno, že účinnost sorbentů závisí na jejich složení a texturních vlastnostech a může být zvýšena pomocí jejich modifikace. The occurrence of contaminants in water sources, microplastics or other organic pollutants, has been an increasing environmental problem. This issue is related to mapping of their occurrence in an aquatic environment and with finding of possible ways regarding their elimination. The prepared microplastic particles of five most-frequently used plastics (polyethylene, polyamide, polytetrafluoroethylene, polyethylene glycol terephthalate and polystyrene) were characterized by the scanning electron microscopy (SEM), the Raman spectroscopy and the infrared spectroscopy (IR). The obtained microplastic particles were used for preparation of simulated water contaminated with microplastics. The prepared simulated samples of water contaminated with microplastics were used for the development of a methodology for determining the number of contained microplast particles. Furthermore, the possibilities of a microplastic removal from simulated samples by sorbents based on natural bentonites and zeolites were tested. It was confirmed that the effectiveness of sorbents depends on their composition and textural properties and could be increased by their modification. Keywords: bentonity; microplastics; sorption Available in digital repository of the ASCR
Mikroplasty a jejich odstraňování z vod pomocí sorbentů.

Zvýšený výskyt cizorodých látek ve vodních zdrojích, ať už mikroplastů či dalších jiných organických kontaminantů je v současné době stále se zvyšující environmentální problém. Tato problematika úzce ...

Spáčilová, Markéta; Dytrych, Pavel; Krejčíková, Simona; Fajgar, Radek; Šolcová, Olga
Ústav chemických procesů, 2020

Copper complexes with triazoles
Jaklová Dytrtová, Jana; Jakl, M.
2020 - English
Triazoles are artificial chemicals used as fungicides as well as for pharmaceutical treatment. However, their reactivity is highly influenced by the presence of other chemicals. Especially, the presence of copper cations changes the reactivity of triazole by theoretically unexpected way. We have studied the interactions of the triazole ring with copper cations to help explain the reactivity of triazoles as a group. Keywords: triazoles; Cu(I); Cu(II); mass spectrometry; ESI-MS; complexes Available at various institutes of the ASCR
Copper complexes with triazoles

Triazoles are artificial chemicals used as fungicides as well as for pharmaceutical treatment. However, their reactivity is highly influenced by the presence of other chemicals. Especially, the ...

Jaklová Dytrtová, Jana; Jakl, M.
Ústav organické chemie a biochemie, 2020

Separation of triazoles from real samples with capillary electrophoresis
Kovač, Ishak; Jakl, M.; Šolínová, Veronika; Jaklová Dytrtová, Jana
2020 - English
The CE has become one of the advantageous tools in fungicides analysis in complex matrices due to its simplicity and separation efficiency. The separation of a group of thee triazole (i.e. penconazole, tebuconazole, and cyproconazole) fungicides was achieved with CD-MEKC with anionic Sg-CD as a selector at pH=4,8. The background electrolyte consisted of TRIS phosphate buffer (50 mmol/L) and 15 mmol/L SDS. The separation was performed on uncoated fused silica capillary with 500/425 mm (total/effective) length under -15 kV separation voltage. Achieved LOD values with this method were: 0,73, 1,88, 0,60, 1,18 (umol/L) for penconazole, tebuconazole, cyproconazole A and B respectively. Keywords: capillary electrophoresis; penconazole; tebuconazole; cyproconazole; γ-cyclodextrin Available at various institutes of the ASCR
Separation of triazoles from real samples with capillary electrophoresis

The CE has become one of the advantageous tools in fungicides analysis in complex matrices due to its simplicity and separation efficiency. The separation of a group of thee triazole (i.e. ...

Kovač, Ishak; Jakl, M.; Šolínová, Veronika; Jaklová Dytrtová, Jana
Ústav organické chemie a biochemie, 2020

CFD Simulation of a Sub-millimetre Rising Bubble in a Stagnant Liquid.
Crha, Jakub; Basařová, P.; Kašpar, O.
2020 - English
Hydrodynamics of the multiphase apparatus is strongly affected by fluids used in the process. One of the main quantities, which determine the hydrodynamic behaviour is the rising velocity of gaseous bubbles. This velocity can be determined easily in small scale apparatuses, but it can be much more challenging in industrial-scale devices. For that reason, mathematical modeling is used. COMSOL Multiphysics, finite element CFD solver, was used to describe the behaviour of the single bubble rising in aqueous solutions of ethanol and n-propanol. Aqueous solutions of low-carbon alcohols are extensively used in many multiphase chemical processes such as distillation, flotation and in multiphase reactors. Bubble velocities and shapes obtained from the simulation were compared to experimental and theoretical values. Two initial diameters of bubbles were used – 0.6 and 0.8 mm. Terminal velocities and shapes deformations obtained from COMSOL of 0.6 mm bubble were in an agreement with theoretical and experimental values. Keywords: level set; bubble; single Available in digital repository of the ASCR
CFD Simulation of a Sub-millimetre Rising Bubble in a Stagnant Liquid.

Hydrodynamics of the multiphase apparatus is strongly affected by fluids used in the process. One of the main quantities, which determine the hydrodynamic behaviour is the rising velocity of gaseous ...

Crha, Jakub; Basařová, P.; Kašpar, O.
Ústav chemických procesů, 2020

Photocatalytic concrete screeds with self-cleaning and antimicrobial function
Bíbová, Hana; Šubrt, Jan; Pližingrová, Eva; Jakubičková, M.; Sázavská, T.; Dohnálek, P.; Hykrdová, Lenka; Jirkovský, Jaromír
2020 - English
All right reserved. Photocatalytic concrete screeds with self-cleaning and antimicrobial function have been developed and tested. These building materials contain sand grains with deposited composite TiO2/SiO2 layers. Two types of the screeds, grey and white, were prepared and their photoactivity and material characteristics were compared. Commercial TiO2 photocatalysts from several manufacturers were employed. Effects of different parameters, such as temperature of the coated sand calcination, humidity, and surface abrasion, were followed. Mechanical properties of the screeds were analyzed by SEM/XRD microscopy. Photocatalytic activity was tested by means of NOx oxidation (ISO norm 22197-1/2007). Antibacterial activity was evaluated by modified ISO norm 27447/2009 with Bacillus subtilis as a model organism. Keywords: Antimicrobial activity; NOx; Photodegradation; Self-cleaning screed; sem Available in digital repository of the ASCR
Photocatalytic concrete screeds with self-cleaning and antimicrobial function

All right reserved. Photocatalytic concrete screeds with self-cleaning and antimicrobial function have been developed and tested. These building materials contain sand grains with deposited composite ...

Bíbová, Hana; Šubrt, Jan; Pližingrová, Eva; Jakubičková, M.; Sázavská, T.; Dohnálek, P.; Hykrdová, Lenka; Jirkovský, Jaromír
Ústav fyzikální chemie J. Heyrovského, 2020

Photon-upconversion scanner for multiplexed imaging
Hlaváček, Antonín; Křivánková, Jana; Foret, František
2020 - English
In analytical chemistry, multiplexed assays facilitate parallel detection of analytes. The multiplexing reduces the consumption of sample, reagents, and other resources and can be applied for medical diagnostics, the studies of biomolecule interactions, single-cell and singlemolecule assays, environmental monitoring, pathogen detection, multiparameter chemical and biological assays and screening of chemical libraries. Keywords: photon-upconversion scanner; photon-upconversion nanoparticles; droplet microfluidics Fulltext is available at external website.
Photon-upconversion scanner for multiplexed imaging

In analytical chemistry, multiplexed assays facilitate parallel detection of analytes. The multiplexing reduces the consumption of sample, reagents, and other resources and can be applied for medical ...

Hlaváček, Antonín; Křivánková, Jana; Foret, František
Ústav analytické chemie, 2020

Photochemical vapor generation of cobalt for detection by inductively coupled plasma mass spectrometry
Vyhnanovský, Jaromír; Musil, Stanislav
2020 - English
Volatile species of cobalt were generated in a flow-injection system, employing a high-efficiency flow-through UV photoreactor and a formic acid based medium. Optimal generation conditions were found as 10% (v/v) formic acid and 4 mol/L ammonium formate at a flow rate of 4 ml/min. Keywords: photochemical vapor generation; cobalt; inductively coupled plasma mass spectrometry Available in digital repository of the ASCR
Photochemical vapor generation of cobalt for detection by inductively coupled plasma mass spectrometry

Volatile species of cobalt were generated in a flow-injection system, employing a high-efficiency flow-through UV photoreactor and a formic acid based medium. Optimal generation conditions were found ...

Vyhnanovský, Jaromír; Musil, Stanislav
Ústav analytické chemie, 2020

Photon-upconversion nanoparticles for single-mocule immunosensing of cancer biomarkers and bacteria
Farka, Z.; Mickert, M. J.; Hlaváček, Antonín; Poláchová, V.; Kostiv, Uliana; Pastucha, M.; Horák, Daniel; Gorris, H. H.; Skládal, P.
2020 - English
The recent progress in the field of immunoassays has been driven by introduction of various kinds of nanomaterials. In particular, photon-upconversion nanoparticles (UCNPs) proved to be excellent immunoassay labels due to their ability to emit light of shorter wavelengths under near-infrared excitation (anti-Stokes emission), which prevents autofluorescence, minimizes light scattering, and thus reduces the optical background interference. These unique photoluminescent properties allow counting of individual biomolecules labeled with UCNPs by conventional wide-field epiluminescence microscopy and enable the development of single-molecule (digital) immunoassays. We have introduced a novel label based on UCNPs conjugated with streptavidin via poly(ethylene glycol) and applied it in a digital upconversion-linked immunosorbent assay (ULISA) for the detection of a cancer biomarker prostate specific antigen (PSA). The digital readout based on counting of individual immunocomplexes improved the sensitivity 16× compared to conventional analog readout and allowed to reach a limit of detection (LOD) of 23 fg·mL−1 (800 aM). Human serum samples were successfully analyzed achieving an excellent correlation with electrochemiluminescence reference method. The conjugates of UCNPs with streptavidin are also suitable for the detection of pathogenic bacterium Melissococcus plutonius, the causative agent of honeybee disease European foulbrood. The ULISA assay provided an LOD of 340 CFU·mL−1 and successfully analyzed real samples of bees, larvae and bottom hive debris. Due to the high reliability and relatively simple detection scheme, the digital ULISA can pave the way for a new generation of digital immunoassays with a strong potential for commercialization. Keywords: single-molecule detection; photon-upconversion nanoparticle; bioconjugation Available in digital repository of the ASCR
Photon-upconversion nanoparticles for single-mocule immunosensing of cancer biomarkers and bacteria

The recent progress in the field of immunoassays has been driven by introduction of various kinds of nanomaterials. In particular, photon-upconversion nanoparticles (UCNPs) proved to be excellent ...

Farka, Z.; Mickert, M. J.; Hlaváček, Antonín; Poláchová, V.; Kostiv, Uliana; Pastucha, M.; Horák, Daniel; Gorris, H. H.; Skládal, P.
Ústav analytické chemie, 2020

Fast and highly sensitive laser scanner for recording photon-upconversion luminiscence from planar surfaces
Hlaváček, Antonín; Křivánková, Jana; Foret, František
2020 - English
Photon-upconversion nanoparticles (UCNPs) are lanthanide-doped nanocrystals that can be excited by nearinfrared light and emit photon-upconversion luminescence of shorter wavelengths. Advantages of UCNPs include near-infrared excitation, multiple and narrow emission bands, negligible autofluorescence and high stability, which make UCNPs ideal luminescence label for use in biological and chemical assays. These assays - e.g. upconversion-linked immunosorbent assay, western blot, lateral flow assay, gel electrophoresis, thin layer chromatography - commonly require the scanning of a planar surface with a high spatial resolution and an excellent sensitivity. The availability of commercial equipment is recently limited because of the novelty of the photon-upconversion phenomenon. Therefore, we report on the construction of photon-upconversion laser scanner. The scanner consists of a laser scanning head, which is attached to a xy-moving stage. The scanning head itself is constructed as an epiluminescence detector with excitation wavelength of 976 nm. A CCD array spectroscope is connected to the laser head and serves as a sensitive detector of photon-upconversion luminescence. The scanner possesses a spatial resolution of 200 μm, the scanning rate is up to 57 points per second and the sensitivity reaches down to single photon-upconversion nanoparticle. Keywords: photon-upconversion; nanoparticle; laser scanner; hyperspectral imaging Available in digital repository of the ASCR
Fast and highly sensitive laser scanner for recording photon-upconversion luminiscence from planar surfaces

Photon-upconversion nanoparticles (UCNPs) are lanthanide-doped nanocrystals that can be excited by nearinfrared light and emit photon-upconversion luminescence of shorter wavelengths. Advantages of ...

Hlaváček, Antonín; Křivánková, Jana; Foret, František
Ústav analytické chemie, 2020

Respirace půdy smrkového porostu v průběhu čtyř let po aplikaci různých dávek vápnitého dolomitu
Rosíková, J.; Dařenová, Eva; Kučera, A.
2020 - Czech
Studie se zaměřuje na in situ odezvu půdního dýchání při 10 ° C (R10) monokultury smrku norského na aplikaci různých dávek dolomitického vápence (0, 2, 3, 4, 6, 9 a 26 t.ha- 1) po dobu čtyř let. Dýchání půdy bylo měřeno během vegetačních období 2016 - 2019. Kromě toho bylo pH stanoveno v horizontech H a Ah během každé sezóny. Účinek vápnění na dýchání v půdě byl statisticky významný během všech ročních období s výjimkou roku 2017. Největší účinek byl pozorován v první sezóně po vápnění. V květnu 2016 vzrostl R10 na pozemcích s vápnem až o 97% ve srovnání s těmi bez vápna. Půdní dýchání se však přímo úměrně s intenzitou vápnění nezvyšovalo. Zjistili jsme korelaci mezi půdním dýcháním a mikrometeorologickými parametry (teplota a vlhkost), když obě nízkoteplotní vlhkost omezovaly dýchání v půdě. Vzhledem k silné schopnosti pufrovat půdu byl v první studijní sezóně pozorován malý účinek vápnění na kyselost půdy. V následujících sezónách se rozdíly v pH mezi plochami s různou intenzitou vápnění začaly zvyšovat, což však bylo pozorováno pouze v horizontu H. Podstatné zvýšení půdní mikrobiální aktivity doprovázené rychlejším dýcháním po vápnění může vést ke zvýšené hrozbě rychlé mineralizace a ztrátě půdní organické hmoty se všemi jejími negativními dopady\n The study focuses on an in situ response of soil respiration at 10 °C (R10) of the Norway spruce monoculture to the application of the different dolomitic limestone dosages (0, 2, 3, 4, 6, 9 a 26 t.ha-1) over a period of four years. Soil respiration was measured within the growing seasons 2016 – 2019. Moreover, the pH was determined in the H and Ah horizons during each season. The effect of liming on soil respiration was statistically significant during all the seasons except for 2017. The greatest effect was observed within the first season after liming. In May 2016, R10 in the limed plots increased as much as by 97% compared to the non-limed ones. However, soil respiration did not increase in the direct proportion to the liming intensity. We found out the correlation between soil respiration and the micrometeorological parameters (temperature and moisture) when both low temperature moisture limited soil respiration. Due to the strong soil buffering capacity, the small effect of liming on the soil acidity was observed in the first study season. In the following seasons, the differences in the pH among the plots with the different liming intensity started to increase, which was, however, observed only in the H horizon. The substantial increase in the soil microbial activity accompanied with faster respiration after liming can lead to the increased threat of rapid mineralization and the loss of soil organic matter with all its negative impacts Keywords: mineralization; r10; liming; ph; picea abies Available at various institutes of the ASCR
Respirace půdy smrkového porostu v průběhu čtyř let po aplikaci různých dávek vápnitého dolomitu

Studie se zaměřuje na in situ odezvu půdního dýchání při 10 ° C (R10) monokultury smrku norského na aplikaci různých dávek dolomitického vápence (0, 2, 3, 4, 6, 9 a 26 t.ha- 1) po dobu čtyř let. ...

Rosíková, J.; Dařenová, Eva; Kučera, A.
Ústav výzkumu globální změny , 2020

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