No (6907)
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6907
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A New Hollow Fiber-Based Liquid-Phase Microextraction Method for the Determination of Antihypertensive Drug Lercanidipine in Biological Samples
Labzova, O.; Hrdlička, Vojtěch; Navrátil, Tomáš; Šelešovská, R.
2024 - English
A new hollow fiber-based liquid-phase microextraction (HF-LPME) method for the determination of antihypertensive drug lercandipine (LCN) in biological samples was developed. HF-LPME was\ncombined with optimized square wave voltammetry (SWV) on a cathodically pre-treated screenprinted boron-doped diamond electrode (SP-BDDE). Optimum HF-LPME conditions were:\nsupported liquid membrane (SLM) dodecane, 0.02 mol L-1 Britton-Robinson buffer (BRB, pH = 3) acceptor phase, BRB (pH = 7) donor phase, and time of extraction 30 min. Limits of quantification (LOQ) and detection (LOD) were 3.3 and 1.1 nmol L-1, respectively. The applicability of the developed method was verified on human urine, blood serum, and blood plasma with 20 and 100 nmol L-1 LCN addition.
Keywords:
Lercanidipine hydrochloride; Hollow fiber liquid-phase microextraction; Screenprinted boron-doped diamond electrode
Available on request at various institutes of the ASCR
A New Hollow Fiber-Based Liquid-Phase Microextraction Method for the Determination of Antihypertensive Drug Lercanidipine in Biological Samples
A new hollow fiber-based liquid-phase microextraction (HF-LPME) method for the determination of antihypertensive drug lercandipine (LCN) in biological samples was developed. HF-LPME was\ncombined with ...
Evaluation of root system architecture and osmotic adaptation in barley
Klem, Karel; Findurová, Hana; Urban, Otmar; Holub, Petr
2024 - Czech
Drought tolerance based on improving root system architecture, in particular by increasing rooting depth, increasing root density at deeper layers, or osmotic adjustment, is one of the most effective ways of adapting to drought, especially in conditions where sufficient water remains in the deeper soil layers during the dry season. Moreover, osmotic adjustment is a trait that allows plants to take up water even when water availability is limited, including the deeper soil layers. On the other hand, however, these are traits that are very difficult to evaluate, given their hidden nature or the need to laboriously excavate roots growing in the soil. This is also the reason why, despite their considerable importance, these features have long been overlooked. Breeding for these traits is done only indirectly by evaluating yield response to drought or indirect physiological or morphological parameters. \nIn this methodology, three methods for evaluating root system architecture or osmotic adjustment are presented which allow selection for specific root system architecture traits or osmotic adjustment, to be carried out on a large number of genotypes, using a relatively simple method based on the cultivation of roots on black filter paper, either hydroponically or aeroponically. This method allows a detailed analysis of root system architecture parameters that are important for drought tolerance and also a relatively easy test of osmotic adjustment by inducing osmotic stress with polyethylene glycol (PEG) solution. Both methods have been successfully validated, in the first case in a model experiment with nutrient deficiency, in which the effect on root system architecture is confounded, and in the second case in a set of barley genetic resources and varieties in which previously obtained information on drought tolerance of some genotypes was confirmed. \nAnother of the methods presented is the cultivation of roots in rhizoboxes filled with sand with a grid of spikes that hold the roots in the position in which they grew when washed. This method again allows the root system architecture to be assessed, but in this case under conditions that more closely match real soil conditions. The method was validated in three barley genotypes with contrasting root system vigor. The method used not only demonstrated the expected differences in rooting depth and root density distribution but also showed a relationship to the physiological response to reduced water availability in terms of photosynthetic CO2 assimilation rate. \nTherefore, all the methods presented here are suitable tools to help breeders in the selection of drought-tolerant barley genotypes. Tolerance vůči suchu, založená na zlepšení architektury kořenového systému, zejména pak na zvýšení hloubky zakořenění, zvýšení hustoty kořenů ve větší hloubce, nebo na schopnosti osmotického přizpůsobení, představuje jeden z nejefektivnějších způsobů adaptace k suchu, zejména pak v podmínkách, kde v období sucha zůstává dostatek vody v hlubších vrstvách půdy. Osmotické přizpůsobení navíc představuje znak, který umožňuje rostlinám příjem vody i při její omezené dostupnosti, včetně snížené dostupnosti v hlubších vrstvách půdy. Na druhou stranu se ovšem jedná o znaky, které jsou velmi obtížně vyhodnotitelné, vzhledem k jejich skrytému charakteru nebo nutnosti pracného odkrývání kořenů rostoucích v půdě. To je také důvod, proč jsou tyto znaky i přes jejich značný význam dlouhodobě přehlíženy. Šlechtění na tyto znaky probíhá fakticky pouze nepřímo pomocí vyhodnocení výnosové reakce na sucho, nebo nepřímých fyziologických či morfologických parametrů. \nV této metodice jsou představeny tři metody vyhodnocení architektury kořenového systému nebo osmotického přizpůsobení, které umožňují provedení selekce na zvolené znaky kořenového systému či osmotického přizpůsobení u velkého počtu genotypů s využitím relativně jednoduché metody založené na kultivaci kořenů na černém filtračním papíru ať již hydroponicky nebo aeroponicky. Tato metoda umožňuje podrobnou analýzu parametrů architektury kořenového systému, které jsou důležité pro toleranci k suchu a rovněž také relativně snadný test osmotického přizpůsobení pomocí indukce osmotického stresu roztokem polyethylen-glykolu (PEG). Obě metody byly úspěšně validovány, v prvním případě na modelovém experimentu s deficitem živin, u kterého je zmámý vliv na architekturu kořenového systému, a v druhém případě na souboru genetických zdrojů a odrůd ječmene, v němž byly potvrzeny dříve získané informace o toleranci některých genotypů k suchu. \nDalší z prezentovaných metod je kultivace kořenů v rhizoboxech naplněných pískem se sítí hrotů, které udržují kořeny při vymývání v poloze, v jakých kořeny rostly. Tato metoda umožňuje opět posouzení architektury kořenového systému, nicméně v tomto případě v podmínkách, které lépe odpovídají reálné situaci v půdě. Validace metody proběhla u tří genotypů ječmene s kontrastní mohutností kořenového systému. Použitá metoda prokázala nejen předpokládané rozdíly v hloubce zakořenění a distribuci hustoty kořenů, ale rovněž prokázala vztah k fyziologické odezvě na sníženou dostupnost vody v podobě rychlosti fotosyntetické asimilace CO2. \nVšechny předkládané metody proto představují vhodný nástroj, který by měl pomoci šlechtitelům v selekci genotypů ječmene tolerantních k suchu. \n\n
Keywords:
spring barley; drought; drought tolerance; root system architecture; root phenotyping; osmotic adjustment; plant physiology
Available at various institutes of the ASCR
Evaluation of root system architecture and osmotic adaptation in barley
Drought tolerance based on improving root system architecture, in particular by increasing rooting depth, increasing root density at deeper layers, or osmotic adjustment, is one of the most effective ...
Book of Abstracts and Programme
Beneš, Hynek; Starý, Zdeněk
2024 - English
The Book of Abstracts and Programme contains time order and the summaries of all the contributions to the international conference “Polymers for Sustainable Future 2024” was organized simultaneously as the 85th Prague Meeting on Macromolecules (PMM) and 11th Conference on Green Chemistry and Nanotechnologies in Polymeric Materials. The participants presented 84 lectures and 91 posters.
Keywords:
polymers; sustainable; green chemistry
Available at various institutes of the ASCR
Book of Abstracts and Programme
The Book of Abstracts and Programme contains time order and the summaries of all the contributions to the international conference “Polymers for Sustainable Future 2024” was organized simultaneously ...
Surfactant-free silver nanofluids as liquid systems with neuromorphic potential
Nikitin, D.; Biliak, K.; Lemke, J.; Protsak, M.; Pleskunov, P.; Tosca, M.; Ali-Ogly, S.; Červenková, V.; Adejube, B.; Bajtošová, L.; Černochová, Zulfiya; Prokeš, J.; Křivka, I.; Biederman, H.; Faupel, F.; Vahl, A.; Choukourov, A.
2024 - English
Neuromorphic engineering is a rapidly developing branch of science that aims to implement the unique attributes of biological neural networks in artificial devices. Most neuromorphic devices are based on the resistive switching effect, which involves changing the device’s conductivity in response to an external electric field. For instance, percolating nanoparticle (NP) networks produced by gas aggregation cluster sources (GAS) show collective spiking behavior in conductivity reminiscent of brain-like dynamics. Nevertheless, the problem of dynamic spatial reconfiguration in solid-state neuromorphic systems remains unsolved. Herein, novel nanofluids with resistive switching properties are proposed as neuromorphic media. They are produced by depositing silver NPs from GAS into vacuum-compatible liquids (paraffin, silicon oil, and PEG) without the use of surfactants or other chemicals. When the electric field is applied between two electrodes, the migration of NPs toward biased electrode is detected in all liquids. The electrophoretic nature of the NP movement was proved by means of ζ-potential measurements. Such movement led to the self-assembly of NPs in conductive paths connecting the electrodes and, as a result, to resistive switching. The electrical response was strongly dependent on the dielectric constant of the base liquid. The Ag-PEG nanofluid demonstrated the best switching performance reproducible during several tens of current-voltage cycles. The growth of flexible and reconfigurable conductive filaments in nanofluids makes them suitable media for potential realization of 3D neural networks.
Keywords:
nanofluid; gas aggregation cluster source; ζ-potential, electrophoresis
Available at various institutes of the ASCR
Surfactant-free silver nanofluids as liquid systems with neuromorphic potential
Neuromorphic engineering is a rapidly developing branch of science that aims to implement the unique attributes of biological neural networks in artificial devices. Most neuromorphic devices are based ...
Electrochemical Properties of Pretomanid. New drug for Tuberculosis Treatment
Deri, M.; Vespi, M.; Giannarelli, S.; Hromadová, Magdaléna
2024 - English
The electrochemical behavior of Pretomanid (PA 824) has been investigated in acetonitrile by cyclic voltammetry at different scan rates and compared to dimetridazole reduction in order to elucidate its redox mechanism. Both compounds show similar reduction behavior in the aprotic solvent that involves one electron transfer to the nitro group. The reduction of Pretomanid is more difficult and the stability of its nitro anion radical is much lower compared to the dimetridazole molecule.
Keywords:
pretomanid; dimetridazole; cyclic voltammetry; reduction mechanism
Available on request at various institutes of the ASCR
Electrochemical Properties of Pretomanid. New drug for Tuberculosis Treatment
The electrochemical behavior of Pretomanid (PA 824) has been investigated in acetonitrile by cyclic voltammetry at different scan rates and compared to dimetridazole reduction in order to elucidate ...
Redox Properties of Pyrene-Cyclohexene Conjugates – Electrochemical Study
Koláčná, Lucie; Čubiňák, M.; Tobrman, T.; Ludvík, Jiří
2024 - English
The series of 16 compounds for "organic electronics" comprising the double-bond cyclohexene core extended by pyrene and/or other aromatics were electrochemically characterized by rotating disk voltammetry in N,N-dimethylformamide. Due to multiple substitutions, the resulting potential gap represents the sum of all substituent effects. Different combinations of substituents can be used to achieve the desired properties of cyclohexene-pyrene derivatives. The electrochemical data presented in this contribution facilitate further tuning of properties of these molecules and systems to achieve features required in material chemistry just by means of chemical modification.
Keywords:
pyrene; cyclohexene; conjugation
Available on request at various institutes of the ASCR
Redox Properties of Pyrene-Cyclohexene Conjugates – Electrochemical Study
The series of 16 compounds for "organic electronics" comprising the double-bond cyclohexene core extended by pyrene and/or other aromatics were electrochemically characterized by rotating disk ...
Electrochemical Valorization of Lignocellulosic Biomass Amination of Furfural and 5-Hydroxymethylfurfural
Donkeng Dazie, Joel; Koláčná, Lucie; Urban, Jiří; Lamač, Martin; Ludvík, Jiří
2024 - English
Furfural (FF) and 5-hydroxymethylfurfural (HMF) isolated from waste lignocellulosic biomass represent renewable sources. The present contribution deals with the transformation of FF and HMF into furfuryl amines which are important precursors namely for pharmaceutical synthesis. First, FF and HMF underwent condensation reactions with various amines which were electrochemically monitored to optimize the process. The resulting Schiff bases were identified by NMR and subsequently electrochemically reduced in basic media. The vicinal diamine (aminopinacol) was the main product besides the expected furfuryl amines. This reaction is a contribution to green synthesis because it was performed electrochemically, in water, and without any metallic catalysts.
Keywords:
furfural; 5-hydroxymethylfurfural; (di)amines
Available on request at various institutes of the ASCR
Electrochemical Valorization of Lignocellulosic Biomass Amination of Furfural and 5-Hydroxymethylfurfural
Furfural (FF) and 5-hydroxymethylfurfural (HMF) isolated from waste lignocellulosic biomass represent renewable sources. The present contribution deals with the transformation of FF and HMF into ...
Electrochemical Properties of Newly Synthesized Selaginpulvilins
Dostálová, L.; Sokolová, Romana; Schwarzová-Pecková, K.; Rýček, L.
2024 - English
The electrochemical properties of newly synthesized selaginpulvilin were investigated by cyclic voltammetry and UV-Vis spectroelectrochemistry. The subject of the study were two\nselaginpulvilins differing in the presence of a hydroxyl group in the media of 0.1 mol L-1 tetrabutylammonium hexafluorophosphate as supporting electrolyte in anhydrous acetonitrile. Both\ncompounds provided an oxidative signal in the positive region until +2.0 V.
Keywords:
oxidation; cyclic voltammetry; selaginpulvilins
Available on request at various institutes of the ASCR
Electrochemical Properties of Newly Synthesized Selaginpulvilins
The electrochemical properties of newly synthesized selaginpulvilin were investigated by cyclic voltammetry and UV-Vis spectroelectrochemistry. The subject of the study were two\nselaginpulvilins ...
3D-printed Electrodes with Nearly Ideal Charge Transfer Characteristics
Vaněčková, Eva; Sebechlebská, Táňa; Kolivoška, Viliam
2024 - English
3D printing is an outstanding manufacturing tool for prototyping customized designs at reduced time and costs, having found applications in fields such as medicine or the automotive industry. The development of printable electrically conductive composite materials brought a revolution to electrochemistry, with 3D-printed electrodes being intensively studied from the viewpoint of\nanalytical performance and stability. However, it is often reported that 3D-printed electrodes have poor charge transfer characteristics, typically due to limited exposure of the electrically conductive phase at the composite surface to the surrounding solution. In this work, we devise and apply simple electrochemical activation procedures that lead to a significant improvement of charge transfer characteristics of 3D printed electrodes.
Keywords:
three-dimensional printing; electrochemistry; electrodes
Available on request at various institutes of the ASCR
3D-printed Electrodes with Nearly Ideal Charge Transfer Characteristics
3D printing is an outstanding manufacturing tool for prototyping customized designs at reduced time and costs, having found applications in fields such as medicine or the automotive industry. The ...
Methods of sewage sludge treatment for agricultural applications with respect to micropollutants
Vítková, M.; Komárek, M.; Wickramasinghe, N.; Pohořelý, Michael; Moško, Jaroslav; Hušek, Matěj; Cajthaml, Tomáš; Grasserová, Alena; Čechmánková, J.; Vácha, R.; Zimová, M.
2024 - Czech
The aim of the methodology is to describe the possibilities of sewage sludge treatment by composting and pyrolysis for the application in agriculture, with particular respect to the so-called micropollutants, but also to conventional pollutants, and to assess the risks of treated sludge for the soil environment and the uptake of (micro)pollutants by cultivated crops. The methodology is based on the results from laboratory and field experiments of a three-year project and on a critical approach to sludge as a potentially hazardous waste on the one hand and a recyclable source of nutrients on the other. Cílem předkládané metodiky je popsat možnosti úpravy čistírenských kalů kompostováním a pyrolýzou pro aplikaci v zemědělství, a to zejména s ohledem na tzv. mikropolutanty, ale i na konvenční polutanty, a posoudit rizika upravených kalů pro půdní prostředí a vstup (mikro)polutantů do pěstovaných plodin. Metodika vychází z výsledků laboratorních a terénních experimentů tříletého projektu a z kritického přístupu ke kalům jako potenciálně nebezpečnému odpadu na straně jedné a recyklovatelného zdroje živin na straně druhé.
Keywords:
pyrolysi; composting; emerging pollutants; soil; plant uptake; leaching
Available on request at various institutes of the ASCR
Methods of sewage sludge treatment for agricultural applications with respect to micropollutants
The aim of the methodology is to describe the possibilities of sewage sludge treatment by composting and pyrolysis for the application in agriculture, with particular respect to the so-called ...
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