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Application of In situ TR Spectroelectrochemical Techniques in Determination of Redox Mechanism of Bioactive Compounds
Sokolová, Romana; Jiroušková, Eliška; Degano, I.; Wantulok, J.; Nycz, J.
2023 - anglický
The electron transfer reactions play an important role in many natural processes. Reactions such as \ndissociation, protonation, and reactions with water and other small molecules often occur in \nbiotransformation. The reaction schemes involving these chemical reactions coupled to the \nelectron transfer can be determined by cyclic voltammetry. Additionally, in \nsitu spectroelectrochemistry can efficiently contribute to the determination of oxidation or \nreduction mechanism. This technique provides information about the electroactive chromophore during \nthe redox process allowing to identification the first reaction intermediates. The final reaction \nproducts were identified by chromatographic techniques. This study represents a key role of TR \nspectroelectrochemistry in the determination of reaction intermediates in the case of \n1,10- phenanthroline derivative substituted by bioactive phenothiazine unit and \ndrug 3- fluorophenmetrazine (2-(3-fluorophenyl)-3-methylmorpholine, 3-FPM). Co pound 3-FPM\nhave recently appeared as the new psychoactive substance in the drug market.\n
Klíčová slova:
IR spectroelectrochemistry; psychoactive substances; oxidation mechanism
Plné texty jsou dostupné na vyžádání prostřednictvím repozitáře Akademie věd.
Application of In situ TR Spectroelectrochemical Techniques in Determination of Redox Mechanism of Bioactive Compounds
The electron transfer reactions play an important role in many natural processes. Reactions such as \ndissociation, protonation, and reactions with water and other small molecules often occur in ...
A polarizable reference electrode
Mareček, Vladimír
2023 - anglický
New concept of a reference electrode for electrochemical systems resolves a problem of a poor \npotential stability of refence electrodes based on the distribution of a strongly \nhydrophobic common cation between two immiscible electrolyte solutions (TTTES). The use of a \npolarizable metal electrode instead of a classical reference electrode is demonstrated in \n a modified conventional four-electrode cell with TTTES. A simple battery operated potentiostat \ncontrols the working electrode potential in a three-electrode configuration. The working metal \nelectrode then serves as a polarizable reference organic solvent electrode in a four-electrode \nsystem for the polarization of the water/organic solvent interface.\n\n
Klíčová slova:
reference electrode; liquid/liquid interface; chloride extraction
Plné texty jsou dostupné na vyžádání prostřednictvím repozitáře Akademie věd.
A polarizable reference electrode
New concept of a reference electrode for electrochemical systems resolves a problem of a poor \npotential stability of refence electrodes based on the distribution of a strongly ...
Elektrochemické studium pH závislých redoxních vlastností komplexů mědi s aza-makrocyklickými ligandy
Koláčná, Lucie; Maďar, M.; Kubíček, V.; Ludvík, Jiří
2023 - český
Molekulární elektronika je progresivní směr moderní materiálové chemie. Zabývá se vývojem\nelektronických prvků na úrovni jedné molekuly. Nejdůmyslnější molekulární elektroniku\nnajdeme v přírodě v podobě metaloenzymů. Jedním ze směrů výzkumu jejich modelů jsou\nkomplexy různě substituovaných azamakrocyklů. Předností těchto molekul je jejich stabilita a\ndobře definovaná syntéza. Investigated Cu(II) complexes are based on plain or cross-bridged cyclam. The\nelectrochemically inactive cyclam was modified by carboxylate, phosphonate, or phenolate\npendant arms. Cu(II) represents the main redox center of the complexes. Modification of the\nligand causes a changed pattern of complex redox response in buffered aqueous solution.\nIrreversible Cu(II) reduction results in complex decomposition to amalgamated copper and\nligand in excess. After Cu(0) electrochemical in situ re-oxidation, copper and ligand are recomplexed.\nComplexes undergo isomerization, accelerated by increasing the temperature. The\ninfluence of pH on complex isomerization and the reversibility of its reduction was described.
Klíčová slova:
cyclam; Cu(II) complexes; pendant arms
Plné texty jsou dostupné na vyžádání prostřednictvím repozitáře Akademie věd.
Elektrochemické studium pH závislých redoxních vlastností komplexů mědi s aza-makrocyklickými ligandy
Molekulární elektronika je progresivní směr moderní materiálové chemie. Zabývá se vývojem\nelektronických prvků na úrovni jedné molekuly. Nejdůmyslnější molekulární elektroniku\nnajdeme v přírodě v ...
Determination of Selected Natural Psychoactive Substances in Organic Matrices at 3D Printed Electrodes
Choińska-Mlynarczyk, Marta; Šestáková, Ivana; Navrátil, Tomáš
2023 - anglický
Psilocybin and its derivative psilocin are popular psychoactive substances both as experimental\ntreatments in clinical trials and as illicit drugs. Their potential ability to influence the human\nbrain entails the need for a fast, inexpensive, selective, and sensitive method of their\ndetermination. The aim of our study was the development of new 3D-printed electrodes which\nfulfill these demands and are useful for medical, toxicological, and forensic purposes.\nSuccessful development allows determining in real matrices (human plasma and dried\nmushrooms) concentrations of the order of 1 μmol dm-3.\n
Klíčová slova:
natural psychoactive substances; 3D-printed electrodes; psilocin; psilocybin
Plné texty jsou dostupné na vyžádání prostřednictvím repozitáře Akademie věd.
Determination of Selected Natural Psychoactive Substances in Organic Matrices at 3D Printed Electrodes
Psilocybin and its derivative psilocin are popular psychoactive substances both as experimental\ntreatments in clinical trials and as illicit drugs. Their potential ability to influence the ...
Bioléčiva pohledem hmotníkáře
Hubálek, Martin; Lenčo, J.
2023 - český
Kurz má za cíl představit bioléčiva, která se stávají stále významnější součástí farmakoterapie závažných onemocnění. Pro kontrolu jejich kvality ve farmaceutickém průmyslu hraje důležitou roli hmotnostní spektrometrie. Uvedeme posluchače do problematiky bioléčiv, kterými jsou v tomto pohledu peptidy, proteiny, monoklonální protilátky nebo oligonukleotidy. Z pohledu analytika se zaměříme především na protilátková léčiva, podíváme se na možnosti jejich separace a analýzy pomocí hmotnostní spektrometrie, a to na úrovni intaktních proteinových molekul, protilátkových podjednotek nebo peptidů. The course aims to introduce biotherapeutics, which are becoming an increasingly important part of the pharmacotherapy of serious diseases. Mass spectrometry plays an important role for their quality control in the pharmaceutical industry. We will introduce the audience to biopharmaceuticals, which in this context are peptides, proteins, monoclonal antibodies or oligonucleotides. From the analyst's point of view, we will focus mainly on antibody drugs, looking at the possibilities of their separation and analysis by mass spectrometry, at the level of intact protein molecules, antibody subunits or peptides.
Klíčová slova:
mass spectrometry; biopharmaceuticals; LC-MS
Plné texty jsou dostupné na vyžádání prostřednictvím repozitáře Akademie věd.
Bioléčiva pohledem hmotníkáře
Kurz má za cíl představit bioléčiva, která se stávají stále významnější součástí farmakoterapie závažných onemocnění. Pro kontrolu jejich kvality ve farmaceutickém průmyslu hraje důležitou roli ...
Monitorování životaschopnosti mikrobiální populace v pitné vodě metodou průtokové cytometrie
Maršálková, Eliška; Makieieva, Y.; Kovar, K.
2023 - český
Mikrobiom přírodní vody z artéského vrtu (tj. balené vody tohoto původu) byl charakterizován metodou kombinující fluorescenční barvení buněk a počítání buněk průtokovou cytometrií. Byla sledována změna celkového počtu buněk (TCC) (mikrobiální „otisk prstu“), počtu buněk mrtvých (DCC) a poměr živých buněk s vysokým (HNA) a nízkým (LNA) obsahem nukleových kyselin. Tato pitná voda (tj. obsahující přibližně 14 tisíc buněk na ml) byla upravena technologií CaviPlazmy, při které vznikají peroxid vodíku, ozón a volné radikály. Touto metodou se snižovala životaschopnost (viabilita) mikrobiálních buněk, jak z původního mikrobiomu, tak přidané laboratorní kultury E. coli. Buňky odumíraly, jejich celkový počet se snížil, buňky také lyzovaly a zvyšoval se tak obsah asimilovatelného uhlíku (AOC) v ošetřené vodě. Poznatky z těchto laboratorních pokusů přispívají k porozumění vlivu oxidačních procesů na životaschopnost mikrobiálních buněk a možného budoucího využití těchto technologií pro dezinfekci a ochranu proti opětovnému růstu možných kontaminantů. The microbiome of natural water from an artesian well (i.e., bottled water of this origin) was characterised using a method combining staining with fluorescence dyes and cell counting by flow cytometry. These investigations revealed the microbial fingerprint of such high-quality drinking water (i.e., containing about 14 thousands cells per mL) as well as changes in total cell count (TCC), dead cell count (DCC) and the ratio of living cells with high (HNA) and low (LNA) nucleic acid content. Hydrogen peroxide, ozone, and free radicals were produced in water exposed to CaviPlazma, while cell viability was reduced, both within the original microbiome and in an inoculated laboratory culture of E. coli. In this treated water, microbial cells died, total cell counts decayed by lysis and dissolved assimilable carbon (AOC) increased. Unique findings from these laboratory experiments facilitate our understanding of the effects of oxidation processes on the viability of microorganisms as well as the potential future use of these technologies for drinking water disinfection and protection against regrowth of possible contaminants.
Klíčová slova:
microbiom; flow cytometry; BactoSense device; cells vitality
Plné texty jsou dostupné na vyžádání prostřednictvím repozitáře Akademie věd.
Monitorování životaschopnosti mikrobiální populace v pitné vodě metodou průtokové cytometrie
Mikrobiom přírodní vody z artéského vrtu (tj. balené vody tohoto původu) byl charakterizován metodou kombinující fluorescenční barvení buněk a počítání buněk průtokovou cytometrií. Byla sledována ...
Dissolved and gaseous nitrogen losses in forests controlled by soil nutrient stoichiometry
Oulehle, Filip; Chuman, T.; Hruška, Jakub; Krám, Pavel; Navrátil, Tomáš; Tesař, Miroslav; Ač, Alexander; Urban, Otmar
2023 - anglický
This study investigates the consequences of chronic nitrogen deposition in forests, including its effects on soil and surface water quality, and greenhouse gas emissions. To predict these effects, the authors explore the controls over dissolved and gaseous nitrogen fluxes in temperate forests. Their findings indicate that stream leaching losses of dissolved nitrogen correspond with the nutrient stoichiometry\nof the forest floor, with stream N losses increasing as ecosystems progress towards phosphorus limitation. Soil nitrogen storage increases with oxalate extractable iron and aluminium content. The authors estimate soil gaseous losses based on 15 N stocks, which averaged 2.5±2.2 kg N ha-1 year-1 , comprising 20±14% of total nitrogen deposition. They also extrapolate the current gaseous nitrogen loss flux from forests globally to be 8.9 Tg N year-1 , which represents 39% of current nitrogen deposition to forests worldwide.
Klíčová slova:
nitrogen; catchment; isotope; mass balance; denitrification; carbon; sequestration
Plné texty jsou dostupné v digitálním repozitáři Akademie Věd.
Dissolved and gaseous nitrogen losses in forests controlled by soil nutrient stoichiometry
This study investigates the consequences of chronic nitrogen deposition in forests, including its effects on soil and surface water quality, and greenhouse gas emissions. To predict these effects, the ...
Green approach for the preparation of biosourced ionic liquids and the study of their thermodynamic properties.
Souvenir Zafindrajaona, Mahasoa-Salina
2023 - anglický
This presentation will address a green approach to the synthesis of ionic liquids qualified as biosourced (monocatenar or bolaform systems) from specific agro-resources, according to several principles of green chemistry. As these solvents could be used to solubilize lignocellulosic biomass and/or extract bioactive compounds (from plant sourcing), the physicochemical characteristics (density, viscosity and heat capacity) of pure ILs or mixtures of IL/water must be determined. Preliminary results concerning this last point will be presented.
Klíčová slova:
biosourced ionic liquids; lignocellulosic biomass; thermodynamic properties
Plné texty jsou dostupné v digitálním repozitáři NUŠL
Green approach for the preparation of biosourced ionic liquids and the study of their thermodynamic properties.
This presentation will address a green approach to the synthesis of ionic liquids qualified as biosourced (monocatenar or bolaform systems) from specific agro-resources, according to several ...
Hazardous components: A case study in textile waste management
Shtukaturova, Anastasia
2023 - anglický
Textile waste, a problem that has been somewhat overlooked for many years, is now coming to the fore.1 The textile value chain is long\nand complex, with over 8000 chemicals used in different manufacturing processes.2 A wide variety of chemicals are used in the manufacture of textile products for the improvement of essential properties and performance of textiles. Chemicals used in textiles significantly improve their quality and appearance. However, the harmful effects of these chemicals can occur at various stages of textile production and processing, such as dyeing, printing and finishing, as well as during use by consumers and at the end-of-life stage.3 There is a lack of safety information on the presence and use of all of these chemicals in consumer products.
Klíčová slova:
textile waste; waste management; chemicals
Plné texty jsou dostupné v digitálním repozitáři NUŠL
Hazardous components: A case study in textile waste management
Textile waste, a problem that has been somewhat overlooked for many years, is now coming to the fore.1 The textile value chain is long\nand complex, with over 8000 chemicals used in different ...
Properties and use of high-temperature biochar
Sedmihradská, Anežka
2023 - anglický
Despite being a hot topic in environmental research, biochar and its properties have been mainly investigated from the perspectives of feedstock type and pyrolysis temperature. Few studies have explored the effect of particle size on biochar properties.Even when the effect of particle size on crop efficiency is recognized, there is a lack of corresponding data and analysis.2–7 Therefore, we thoroughly analyzed (proximate and ultimate analysis, SEM, XRD, Raman spectroscopy) four particle size fractions (< 0.5, 0.5–2, 2–5, > 5 mm) of high-temperature biochar from a gasification power plant, the sizes reflecting those of biochar actually used in agriculture. The < 0.5 mm fraction was significantly different in terms of carbon structure, and carbon and ash content. Consequently, pH, electric conductivity and heavy metal content also differed greatly. The corresponding results for the other particle fractions were broadly similar to each other. Interestingly, for all fractions, the porosity and H/C ratio were independent of particle size, meaning that, regardless of size, the investigated biochar fractions are equally stable in soil. The 0.5–2 mm fraction was then selected to be used in different industrial or agricultural processes such as the anaerobic digestion of wastewater or livestock feeding. The effect of biochar on these processes is currently under investigation, providing only initial data so far.
Klíčová slova:
biochar; particle size on biochar; high-temperature biochar
Plné texty jsou dostupné v digitálním repozitáři NUŠL
Properties and use of high-temperature biochar
Despite being a hot topic in environmental research, biochar and its properties have been mainly investigated from the perspectives of feedstock type and pyrolysis temperature. Few studies have ...
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