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Electrochemistry of Acetaminophen
Mikysek, T.; Ludvík, Jiří
2024 - anglický
The contribution is focused on electrochemical oxidation of acetaminophen mainly in non-aqueous media. The influence of various organic solvents as well as the pH effect is described herein. The redox properties of acetaminophen were studied by means of cyclic voltammetry, and rotating-disk voltammetry. We found that the protonation/deprotonation of acetaminophen acts as a ratedetermining step, where the stability of phenoxy radical intermediate plays an important role.
Klíčová slova:
acetaminophen; phenacetine; voltammetry
Plné texty jsou dostupné na vyžádání prostřednictvím repozitáře Akademie věd.
Electrochemistry of Acetaminophen
The contribution is focused on electrochemical oxidation of acetaminophen mainly in non-aqueous media. The influence of various organic solvents as well as the pH effect is described herein. The redox ...
Temoporfin-conjugated upconversion nanoparticles for NIR-induced photodynamic therapy of pancreatic cancer
Shapoval, Oleksandr; Větvička, D.; Kabešová, M.; Engstová, Hana; Horák, Daniel
2024 - anglický
Photodynamic therapy (PDT), a clinically approved cancer treatment strategy, has the potential to cure pancreatic cancer with minimal side effects. PDT primarily uses visible wavelengths to directly activate hydrophobic photosensitizers, which may be insufficient for deep-seated cancer cells in clinical practice due to poor penetration. Upconversion nanoparticles (UCNPs) serve as an indirect excitation source to activate photosensitizers (PSs) in the NIR region, overcoming the limitations of molecular PSs such as hydrophobicity, non-specificity, and excitation in the UV/Vis region. Here, monodisperse upconversion NaYF4:Yb3+, Er3+, Fe2+ nanoparticles (UCNPs) have been surface-engineered with poly(methyl vinyl ether-alt-maleic acid) (PMVEMA) and temoporfin (mTHPC), a clinically used PDT prodrug, for near-infrared (NIR) light-triggered PDT of pancreatic cancer. The incorporation of Fe2+ ions into the particles increased the fluorescence intensity in the red region matching the activation wavelength of mTHPC. Covalent binding of mTHPC to the surface of UCNP@PMVEMA particles provided colloidally stable conjugates enabling generation of singlet oxygen. In vitro cytotoxicity and photodynamic activity of the particles were evaluated using INS-1E rat insulinoma and Capan-2 and PANC-01 human pancreatic adenocarcinoma cell lines. The PDT efficacy of UCNP@PMVEMA-mTHPC conjugates after irradiation with 980 nm NIR light was tested in vivo in a pilot study on Capan-2 human pancreatic adenocarcinoma growing subcutaneously in athymic nude mice. The intratumoral administration of the nanoconjugates significantly hindered tumor growth and demonstrated promising PDT efficacy against human pancreatic cancer.
Klíčová slova:
photodynamic therapy; temoporfin; upconversion nanoparticles
Plné texty jsou dostupné v digitálním repozitáři Akademie Věd.
Temoporfin-conjugated upconversion nanoparticles for NIR-induced photodynamic therapy of pancreatic cancer
Photodynamic therapy (PDT), a clinically approved cancer treatment strategy, has the potential to cure pancreatic cancer with minimal side effects. PDT primarily uses visible wavelengths to directly ...
A New Approach to Determining the Drug Guaifenesin Using Voltammetric and Flow Injection Analysis
Kelíšková, P.; Matvieiev, O.; Sokolová, Romana; Janíková, L.; Behúl, M.; Šelešovská, R.
2024 - anglický
This study presents a new method for detecting guaifenesin (GFE) in pharmaceutical samples. We employed screen-printed sensors with a boron-doped diamond electrode (BDDE) to develop and validate both voltammetric and flow amperometric methods. These approaches were effectively used to analyze model solutions, pharmaceutical preparations, and serum samples spiked with GFE, producing accurate results comparable to those obtained with HPLC/DAD analysis. The developed methods provide straightforward, sensitive, and selective means for determining GFE in various sample matrices, underscoring the potential of SP/BDDE in electrochemical analysis.
Klíčová slova:
guaifenesin; screen-printed sensor; boron-doped diamond electrode
Plné texty jsou dostupné na vyžádání prostřednictvím repozitáře Akademie věd.
A New Approach to Determining the Drug Guaifenesin Using Voltammetric and Flow Injection Analysis
This study presents a new method for detecting guaifenesin (GFE) in pharmaceutical samples. We employed screen-printed sensors with a boron-doped diamond electrode (BDDE) to develop and validate both ...
Optimization of Parameters Used in the Application of Elimination Voltammetry with Linear Scan
Navrátil, Tomáš; Trnková, L.; Hrdlička, Vojtěch; Li, X.
2024 - anglický
Elimination Voltammetry with Linear Scan (EVLS) is a well-established mathematical method that aids in understanding an analyzed electrochemical system. In almost 30 years since its derivation, it has become a “black-box” technique that is applied automatically (in most cases due to its incorporation into a voltammetric software) without thinking about its fundamentals. However, the choice of optimum parameters under which DC voltammetric data (from which elimination curves are calculated) is crucial. This contribution deals with revealing the optimum ratio of applied scan rates and their absolute values (i.e., times of recording) in dependence on the character of the investigated system (diffusion-controlled process, adsorption-controlled process, etc.).
Klíčová slova:
elimination voltammetry with linear scan; optimization; adsorption
Plné texty jsou dostupné na vyžádání prostřednictvím repozitáře Akademie věd.
Optimization of Parameters Used in the Application of Elimination Voltammetry with Linear Scan
Elimination Voltammetry with Linear Scan (EVLS) is a well-established mathematical method that aids in understanding an analyzed electrochemical system. In almost 30 years since its derivation, it has ...
Utilization of electrochemically induced cleavage of various sulfonimides
Salvadori, Karolína
2023 - anglický
In this work, we describe the unexpected electrochemical cleavage of sulfonimides, providing a direct pathway to corresponding sulfonamides. For this purpose, 16 substances were synthesized and tested, reflecting the influence of different electron effects of -SO2Ph-R substituents, and the impact of the number of nosyl units present in molecules. In the case of octakis-nosylated calixarenes, the electrochemical cleavage via direct potential-controlled electrolysis was compared with conventional organic synthetic procedures. After electrolysis, all prepared sulfonamides were isolated in excellent yields.
Klíčová slova:
sulfonimides; green chemistry procedures; electrochemisty
Plné texty jsou dostupné v digitálním repozitáři NUŠL
Utilization of electrochemically induced cleavage of various sulfonimides
In this work, we describe the unexpected electrochemical cleavage of sulfonimides, providing a direct pathway to corresponding sulfonamides. For this purpose, 16 substances were synthesized and ...
Green approach for the preparation of biosourced ionic liquids and the study of their thermodynamic properties\n
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\n
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 ...
Cultivation of Limnospira maxima and utilization of its fresh biomass in human nutrition
Vásquez, Claudia
2023 - anglický
This work aims to enhance productivity, efficiency and sustainability of L. maxima cultivation as well as to determine the safe microbiological conditions for the nutritional use of fresh spirulina biomass. Various parameters such as light intensity, light spectral composition, temperature, pH, CO2, and culture media composition can be optimized. A series of experiments were performed to find the most suitable configuration to cultivate L. maxima, defined by cyanobacterium productivity and yield as well as other metabolites production such as phycocyanin (C-PC) and carotenoids.
Klíčová slova:
Limnospira maxima; fresh biomass; human nutrition
Plné texty jsou dostupné v digitálním repozitáři NUŠL
Cultivation of Limnospira maxima and utilization of its fresh biomass in human nutrition
This work aims to enhance productivity, efficiency and sustainability of L. maxima cultivation as well as to determine the safe microbiological conditions for the nutritional use of fresh spirulina ...
Organic fluorine content and change during thermal treatmen
Hušek, Matěj
2023 - anglický
We have previously described how pyrolysis affected the content of selected PFAS representatives.4,5 However, we could not determine with certainty whether they were merely cleaved or mineralised. Therefore, we focused on the change in organic fluorine content (part of PFAS) and analysed its thermal behaviour in inert (sea sand) and heterogeneous (sewage sludge) material.
Klíčová slova:
organic fluorine; sewage sludge; thermal treatment
Plné texty jsou dostupné v digitálním repozitáři NUŠL
Organic fluorine content and change during thermal treatmen
We have previously described how pyrolysis affected the content of selected PFAS representatives.4,5 However, we could not determine with certainty whether they were merely cleaved or mineralised. ...
Separation of exosomes from polydisperse suspension in microfluidic devices
Paříková, Anna
2023 - anglický
The work included fine-tuning the experimental methodology, writing an in-house code for exosome tracking based on a one-way\napproach, and performing a parametric study to investigate the separation potential of the microdevice as a function of channel geometry, flow rate, and viscosity. Preliminary results show that viscoelasticmicrofluidics can be used as an alternative to conventional e xosome separation techniques.
Klíčová slova:
separation techniques; exosomes; microfluidic devices
Plné texty jsou dostupné v digitálním repozitáři NUŠL
Separation of exosomes from polydisperse suspension in microfluidic devices
The work included fine-tuning the experimental methodology, writing an in-house code for exosome tracking based on a one-way\napproach, and performing a parametric study to investigate the separation ...
HIGHLY-TIME RESOLVED ELEMENTAL SOURCE APPORTIONMENT OF PM2.5 AT AN URBAN TRAFFIC SITE IN PRAGUE
Windell, Laurence Christian; Pokorná, Petra; Ondráček, Jakub; Schwarz, Jaroslav; Lhotka, Radek; Vodička, Petr; Zíková, Naděžda; Hopke, P.K.; Ždímal, Vladimír
2023 - anglický
This work aims to quantify metal emissions from traffic at an urban traffic site in Prague, Czech Republic, identify key tracers of emissions, and investigate exhaust and non-exhaust emissions observable in fine particulate matter (PM2.5). This project signifies the first high-time resolution elemental analysis of Prague aerosols.
Klíčová slova:
source apportionment; traffic; online
Plné texty jsou dostupné v digitálním repozitáři NUŠL
HIGHLY-TIME RESOLVED ELEMENTAL SOURCE APPORTIONMENT OF PM2.5 AT AN URBAN TRAFFIC SITE IN PRAGUE
This work aims to quantify metal emissions from traffic at an urban traffic site in Prague, Czech Republic, identify key tracers of emissions, and investigate exhaust and non-exhaust emissions ...
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