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Copper complexes with triazoles
Jaklová Dytrtová, Jana; Jakl, M.
2020 - anglický
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.
Klíčová slova:
triazoles; Cu(I); Cu(II); mass spectrometry; ESI-MS; complexes
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
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 ...
Separation of triazoles from real samples with capillary electrophoresis
Kovač, Ishak; Jakl, M.; Šolínová, Veronika; Jaklová Dytrtová, Jana
2020 - anglický
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.
Klíčová slova:
capillary electrophoresis; penconazole; tebuconazole; cyproconazole; γ-cyclodextrin
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
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. ...
Application potential of screening in vitro toxicological assays in qualitative risk assessment of nanomaterials
Závodná, Táňa; Topinka, Jan; Danihelka, J.
2020 - anglický
Undeniable benefits of engineered nanomaterials might be discredited by their potential enhanced or unexpected toxicity arising from nano-specific properties and behavior. An analysis of the applicability of the traditional chemical risk assessment approach in nanomaterials revealed high levels of uncertainty in both hazard characterization and exposure assessment due to the lack of relevant validated methods and reliable data. This indicates the limited capability of the conventional risk assessment approach to ensure the safe use of nanomaterials. Based on the identified uncertainties, the control banding approach was proposed as a suitable tool for preliminary qualitative risk assessment of nanomaterials in occupational settings. Control banding categorizes hazard and exposure into levels referred to as bands. The combination of the hazard and exposure bands results in a risk band determining the necessary degree of control and regulatory measures. To decrease the number of cases where, based on the precautionary principle, unavailable experimental or field data would lead to the assignment to the highest hazard category requiring costly exposure control, screening evaluation of nanomaterial toxicity was proposed as an additional decision criterion. For this purpose, a battery of in vitro toxicological assays enabling screening evaluation of potential toxic effects of NMs was proposed. The assays evaluate endpoints covering basic toxic effects of substances (cytotoxicity, genotoxicity), as well as known nonspecific mechanisms of toxicity typical for nanomaterials (oxidative stress, inflammation). The proposed risk management strategy is intended to assist small and medium-sized enterprises to implement adequate measures to ensure employee safety.
Klíčová slova:
toxicity; tool; industrial poisons
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Application potential of screening in vitro toxicological assays in qualitative risk assessment of nanomaterials
Undeniable benefits of engineered nanomaterials might be discredited by their potential enhanced or unexpected toxicity arising from nano-specific properties and behavior. An analysis of the ...
Mikroplasty a jejich odstraňování z vod pomocí sorbentů.
Spáčilová, Markéta; Dytrych, Pavel; Krejčíková, Simona; Fajgar, Radek; Šolcová, Olga
2020 - český
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.
Klíčová slova:
bentonity; microplastics; sorption
Plné texty jsou dostupné v digitálním repozitáři Akademie Věd.
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 ...
Males-females differences in the spectrum of chromosomal aberrations in the group of nanocomposites production workers
Rössnerová, Andrea; Pelcová, D.; Ždímal, Vladimír; Elzeinova, Fatima; Margaryan, Hasmik; Chvojková, Irena; Topinka, Jan; Schwarz, Jaroslav; Ondráček, Jakub; Koštejn, Martin; Komarc, M.; Vlčková, Š.; Fenclová, Z.; Lischková, L.; Dvořáčková, Š.; Rössner ml., Pavel
2020 - anglický
An increase in the use of nanomaterials (NM) has been witnessed in many areas of human life. Therefore, assessment of genotoxicity of NM and nanoparticles (NP) is one of the main objectives of genetic toxicology. Despite this fact, human cytogenetic studies following the exposure to NP are still rare. Moreover, no relevant information on possible differences in sensitivity to NP related to gender is available.\n\nIn this study we periodically (in September 2016, 2017 and 2018; pre-shift and post-shift each year) analyzed a group of workers (both genders), working long time in nanocomposites research, and matched controls. Aerosol exposure monitoring of particulate matter including nano-sized fractions was carried out during working shift. Micronucleus assay using Human Pan Centromeric probes, was applied to distinguish, besides the frequency of total MN in binucleated cells (BNC), also other types of chromosomal damage (losses and breaks). Moreover, whole-chromosome painting (WCP) for autosome #1 and both gonosomes (X and Y) were applied in third sampling period (2018) with the aim to identify the particular structural and numerical chromosomal aberrations.\n\nObtained results showed: (i) differences in the risk of exposure to NP related to individual working processes (welding, smelting and machining); (ii) differences in chemical composition of nano-fraction; (iii) no effect of chronic exposure of NP (total MN) opposite to significant effect of acute exposure; (iv) gender-related DNA damage differences (females seem to be more sensitive to chromosomal losses). Additional data from WCP suggested increased frequency of numerical aberrations in gonosomes.
Klíčová slova:
DNA damage; gender; chromosomal aberrations; micronuclei; nanoparticles; occupational exposure
Plné texty jsou dostupné v digitálním repozitáři NUŠL
Males-females differences in the spectrum of chromosomal aberrations in the group of nanocomposites production workers
An increase in the use of nanomaterials (NM) has been witnessed in many areas of human life. Therefore, assessment of genotoxicity of NM and nanoparticles (NP) is one of the main objectives of genetic ...
Lead soaps in paintings: symptoms and the role of humidity
Garrappa, Silvia; Švarcová, Silvie; Kočí, Eva; Hradilová, J.; Bezdička, Petr; Hradil, David
2020 - anglický
In this study, an overview of the symptoms of lead soaps reported in artworks in combination\nwith the study of the role of humidity on the formation of these degradation products have\nbeen thoroughly investigated. The use of optical microscopy, scanning electron microscopy\n(SEM) in combination with Fourier-transform infrared spectroscopy (FTIR) proved to be an\nefficient analytical approach to highlight both the saponified area of artworks’ samples and the\nformation of metal carboxylates within mock-up model systems. Optical microscopy revealed\nto be very useful for the first screening of samples embedded in resin, while SEM helped in\nthe detection and distribution of elements within the cross-sections. On the other hand, FTIR\nmicroscope proved to be a very powerful instrument for high-resolution point measurements\nperformed in the attenuated total reflection mode (ATR) mode with mercury-cadmium-telluride\n(MCT) detector, as well as for chemical imaging of larger area of both artworks’ and mock-up\nsamples performed in the ATR mode with focal plane arrays (FPA) detector. This study provides\nnew useful insights contributing to better understanding of factors affecting the paints‘ stability,\nwhich is neccesary for developing new efficient strategies for preservation and restoration of\nfatty-based painted artworks.
Klíčová slova:
lead soaps; paintings; oil; egg yolk; humidity
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Lead soaps in paintings: symptoms and the role of humidity
In this study, an overview of the symptoms of lead soaps reported in artworks in combination\nwith the study of the role of humidity on the formation of these degradation products have\nbeen ...
Trophic and Hydric Soil Series in the Floodplain of Natural Submountain Gravel-Carrying Moravka River in the Outer Western Carpathians
Rychtecká, P.; Rosíková, J.; Samec, Pavel
2020 - český
Klasifikace půdních řad je základním přístupem pro hodnocení vztahů\nmezi půdními podmínkami a vegetací. V této studii bylo situováno hodnocení půdní řady\ndo přirozeně zalesněné vněkarpatské štěrkonosné nivy podél řeky Morávky\n(336–383 m n. m., Česká republika). Klasifikace byla provedena geobiocenologicky společností\ntrofické a hydrické řady na fluviálních formách (FL) barů a aktivních až terasových nivách\npři využití intervalů pedochemických a hydrofyzikálních vlastností. Rozdíly mezi\nvlastnosti půdy na FL byly hodnoceny pomocí analýzy rozptylu a diskriminační analýzy.\nFL prokazatelně rozdělily půdní podmínky. Celková oddělitelnost trofické řady byla 84 %\nzatímco oddělitelnost hydrické řady byla 72 %. Oddělitelnost pedochemických vlastností\nbylo 66–81 % mezi FL, ačkoli hydrofyzikální vlastnosti je odlišovaly pouze s\n41-64% přesnost. Barové půdní podmínky byly na rozdíl od teras základní a hydraulicky omezené.\nAktivní záplavové území bylo založeno na necelých 68 % plochy, jinak tam byly\nmezotrofně-bázové podmínky. Půdní podmínky na terasové nivě se výrazně lišily\nmezi ornicí a podložím. Zatímco podloží bylo převážně mezotrofní (58 %) to\nmezotrofně-nitrofilní (40,5 %), ornice byla převážně mezotrofně-nitrofilní.\nSérie lužních půd byly lépe hodnotitelné prostřednictvím pedochemických vlastností než hydrofyzikální. Poměr C/N a pH/H2O ovlivnily trofickou separabilitu více než sorpci půdy.\nRozpor mezi bazickou saturací a kapacitou výměny kationtů naznačoval vývoj půdy\nintenzita na FL. Hydrické řady nivy byly zjistitelné maximální kapilární kapacitou půdy,\nkapacita zadržování vody a provzdušňování. Přechodné jevy v půdní řadě mezi mřížemi a terasou\nlužní indi The soil series classification is the fundamental approach for the evaluation of relations between soil conditions and vegetation. In this study, the evaluation of the soil series was situated into the naturally forested Outer Carpathian gravel-carrying floodplain along the Moravka River (336383 m a.s.l., Czech Republic). The classification was carried out geobiocoenologically by the trophic and hydric series on the fluvial landforms (FLs) of bars and the active to terrace floodplains under using of the pedochemical and hydro-physical properties intervals. The differences among the soil properties on the FLs were evaluated using the analysis of variance and discrimination analysis. The FLs divided the soil conditions demonstrably. Total separability of the trophic series was 84% while separability of the hydric series was 72%. The separabilities of the pedochemical properties were 6681% among the FLs although the hydro-physical properties distinguished them only with 41-64% accuracy. The bar soil conditions were base and hydrically limited in contrast to the terraces. The active floodplain was base on less than 68% of the area, otherwise there were the mesotrophicallybase conditions. The soil conditions on the terrace floodplain patently differed between the topsoil and subsoil. While the subsoil was predominantly mesotrophic (58%) to mesotrophically-nitrophilous (40.5%), the topsoil was mesotrophically-nitrophilous predominantly.
Klíčová slova:
submountain floodplain; terrace floodplain; soil cation exchange capacity; water-holding capacity
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Trophic and Hydric Soil Series in the Floodplain of Natural Submountain Gravel-Carrying Moravka River in the Outer Western Carpathians
Klasifikace půdních řad je základním přístupem pro hodnocení vztahů\nmezi půdními podmínkami a vegetací. V této studii bylo situováno hodnocení půdní řady\ndo přirozeně zalesněné vněkarpatské ...
A comparative study of covalent glucose oxidase and laccase immobilization techniques at powdered supports for biosensors fabrication
Tvorynska, Sofiia; Barek, J.; Josypčuk, Bohdan; Nesměrák, K.
2020 - anglický
In order to develop the optimal strategy and to deepen the knowledge in the field of enzyme immobilization, three different techniques of covalent binding for two enzymes (glucose oxidase and laccase) at powdered surfaces were compared. Immobilization protocol was optimized by changing supports (two mesoporous silica powders (SBA−15, MCM−41) and a cellulose powder), the functionalized\ngroups introduced at support surfaces (−NH and −COOH), and the methods of activation (glutaraldehyde and carbodiimide). Amino and carboxyl functionalized mesoporous silica and cellulose powders\nwere prepared by silanization using (3-aminopropyl)triethoxysilane and carboxyethylsilanetriol, respectively. It was found that coupling of both enzymes by their –NH groups through glutaraldehyde to -NH functionalized supports, in particular SBA15−NH and cellulose−NH for glucose oxidase, MCM41−NH for laccase, showed the highest activity and the best stability.
Klíčová slova:
biosensors; covalent immobilization; enzymatic reactor
Dokument je dostupný na externích webových stránkách.
A comparative study of covalent glucose oxidase and laccase immobilization techniques at powdered supports for biosensors fabrication
In order to develop the optimal strategy and to deepen the knowledge in the field of enzyme immobilization, three different techniques of covalent binding for two enzymes (glucose oxidase and laccase) ...
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 - anglický
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.
Klíčová slova:
Antimicrobial activity; NOx; Photodegradation; Self-cleaning screed; sem
Plné texty jsou dostupné v digitálním repozitáři Akademie Věd.
Photocatalytic concrete screeds with self-cleaning and antimicrobial function
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. ...
CFD Simulation of a Sub-millimetre Rising Bubble in a Stagnant Liquid.
Crha, Jakub; Basařová, P.; Kašpar, O.
2020 - anglický
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.
Klíčová slova:
level set; bubble; single
Plné texty jsou dostupné v digitálním repozitáři NUŠL
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 ...
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