No (3356)
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3356
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UV-Vis and IR Spectroelectrocbemistry of Copper Complexes and Bioactive Compounds
Sokolová, Romana; Obluková, Michaela; Sýs, M.; Mikysek, T.; Wantulok, J.; Nycz, J. E.; Degano, I.
2021 - English
The interpretation of the change of absorption spectrum of an oxidized and reduced molecule\nrecorded during the electron transfer is an efficient tool for the determination of oxidation or\nreduction mechanism. This technique provides the information about the electroactive\nchromophore and is performed in two regimes of electrochemical measurement, cyclic\nvoltammetry and chronoamperometry, respectively. This approach was successfully applied to\nstudy the fundamental electrochemical behavior of recently synthesized copper complexes\nproviding biomimetic activity, ofpolyphenolic bioactive compounds, and also for the reduction\nof halogenated phenanthrolines. The identification of redox products was done by\nchromatographic techniques as HPLC-DAD and HPLC-ESI-MS/MS.
Keywords:
Copper complexes; Catechol; spectroelectrochemistry
Available on request at various institutes of the ASCR
UV-Vis and IR Spectroelectrocbemistry of Copper Complexes and Bioactive Compounds
The interpretation of the change of absorption spectrum of an oxidized and reduced molecule\nrecorded during the electron transfer is an efficient tool for the determination of oxidation or\nreduction ...
Estimation of winter wheat yield using machine learning from airborne hyperspectral data
Švik, Marian; Pikl, Miroslav; Janoutová, Růžena; Veselá, Barbora; Slezák, Lukáš; Klem, Karel; Homolová, Lucie
2021 - English
Methods based on optical remote sensing allow nowadays to assess crop conditions over larger areas. The assessment of crop conditions and potential estimation of crop yields in the early growth\nstages can help farmers to better target their management practice such as application of fertilizers. In this study we analysed airborne hyperspectral images acquired several times during the growing season over two experimental sites in the Czech Republic (Ivanovice and Lukavec). The field experiments on winter wheat included 12 levels of fertilisation (combination of organic and mineral fertilisers). Such an experiment design and the possibility of combining the data from two sites together increased the variability in our wheat yield dataset, which varied between 2.8 and 10.0 t/ha. Further, we used a machine learning method – namely gaussian process regression from the ARTMO toolbox to train two variants of models: a) combining the spectral data from both sites and from the multiple acquisition days and b) combining the spectral data from both sites for individual acquisition days.The results showed that it was feasible to predict wheat yield already at the beginning of April with R2 > 0.85. This promising result, however, requires more thorough validation and therefore we plan to include more data from other sites in the next steps.
Keywords:
hyperspectral; machine learning; remote sensing; winter wheat; yield
Available at various institutes of the ASCR
Estimation of winter wheat yield using machine learning from airborne hyperspectral data
Methods based on optical remote sensing allow nowadays to assess crop conditions over larger areas. The assessment of crop conditions and potential estimation of crop yields in the early ...
Epitachophoretic preconcentration of proteins
Hrušková, Helena; Voráčová, Ivona; Foret, František
2021 - English
In this work, we present a developed method for preconcentration of standards of proteins cytochrome c, myoglobin, and hemoglobin. Firstly, the electrolyte system was selected and optimized to provide low analysis time, narrow shape of the protein zone, and eliminate overheating at the center of the device. In the next step, the developed method was tested on the preconcentration of proteins: cytochrome c, myoglobin, and hemoglobin. After several adjustments myoglobin and hemoglobin were also uccessfully preconcentrated. After evaluation of pilot results, this technique provides up to fiftyfold preconcentration and recovery of over 70 % for each protein. The next plan is to preconcentrate proteins from complex biological matrices such as urine or blood plasma.
Keywords:
epitachophoresis; isotachophoresis; preparative concentration
Available on request at various institutes of the ASCR
Epitachophoretic preconcentration of proteins
In this work, we present a developed method for preconcentration of standards of proteins cytochrome c, myoglobin, and hemoglobin. Firstly, the electrolyte system was selected and optimized to provide ...
Quantum dot luminescent probe for Caspase 3/7 imaging inside cells
Procházková, Markéta; Klepárník, Karel
2021 - English
Two step synthesis of luminescent probe based on ligand-exchange in the first step and the specific reaction of amino group in the second step was optimized. The luminescence properties of the final product were checked by time course of\nactive recombinant caspase protein reaction under the model conditions in fluorimeter. The novel luminescent probe enables long-time imaging of active caspases in living cells or tissues.
Keywords:
caspase; fluorescence; quantum dot
Available on request at various institutes of the ASCR
Quantum dot luminescent probe for Caspase 3/7 imaging inside cells
Two step synthesis of luminescent probe based on ligand-exchange in the first step and the specific reaction of amino group in the second step was optimized. The luminescence properties of the final ...
Ion Transfer Voltammetry across the Polarized Ionic Liquid/Water Interface: Base for Electrochemical Sensors
Langmaier, Jan; Samec, Zdeněk
2021 - English
Some electrochemical techniques such as voltammetry at the polarized interfaces between two\nimmiscible electrolyte solutions (ITIES) represent interesting alternatives to classical\nelectrochemistry. The benefit of the ion transfer voltammetry lies in the possibility of detection\nof ionic species which are not otherwise redox active. The methodology enables apart of direct\ndetermination of ionic samples (including pharmaceutical and clinical ones) also to monitor\nreaction processes (acido-basic, enzymatic, etc.), determination of reaction substrates and\nproducts in one experimental step, evaluation of reaction and transport kinetics, and estimation\nof lipophilicity of involved species.
Keywords:
ion transfer voltammetry; electrochemical detection; ionic liquid
Available on request at various institutes of the ASCR
Ion Transfer Voltammetry across the Polarized Ionic Liquid/Water Interface: Base for Electrochemical Sensors
Some electrochemical techniques such as voltammetry at the polarized interfaces between two\nimmiscible electrolyte solutions (ITIES) represent interesting alternatives to classical\nelectrochemistry. ...
The use of Boron Doped Diamond Electrode for Determination of 5-hydroxyindoleacetic Acid
Hrdlička, Vojtěch; Navrátil, Tomáš
2021 - English
A new method for voltammetric determination of clinical biomarker 5-hydroxyindoleacetic\nacid (HIAA) at the boron-doped diamond electrode (BDDE) was developed. Anodically and\ncathodically pretreated BDDEs were tested in the pH ranges from 1 to 12, pre-treatment at\n+2.0V/60 s, and pH 3 was found to be the optimum.\nThe optimum square wave voltammetry (SWV) parameters were: f = 12 Hz, amplitude 60\nmV, and potential step 4 mV. SWV concentration dependency was constructed in the range\nfrom 0.1 to 100 μmol L−1, limits of determination and detection were 0.3 and 0.1 μmol L−1,\nrespectively. HIAA oxidation electrode process at BDDE was diffusion-controlled, as\nuncovered by cyclic voltammetry. Interestingly, HIAA peak potential was constant in various\nranges of pH, indicating a non-Nernstian behavior at the BDDE, in contrast to a previously\npublished electrooxidation mechanism consisting of a coupled H+/e− transfer.
Keywords:
boron-doped diamond electrode; 5-hydroxyindoleacetic acid; square wave voltammetry
Available on request at various institutes of the ASCR
The use of Boron Doped Diamond Electrode for Determination of 5-hydroxyindoleacetic Acid
A new method for voltammetric determination of clinical biomarker 5-hydroxyindoleacetic\nacid (HIAA) at the boron-doped diamond electrode (BDDE) was developed. Anodically and\ncathodically pretreated ...
Determination of Selected Drugs using 3D Printed Electrodes
Choińska-Mlynarczyk, Marta; Hrdlička, Vojtěch; Navrátil, Tomáš
2021 - English
The main aim of this research was to develop a new method for voltammetric determination of\npopular antidepressants, analgesics, and illicit drugs using a laboratory-made 3D printed\nelectrode and to compare the achieved results with those registered using a commercially\navailable glassy carbon electrode. These experiments represent the first step in the development\nof a method applicable in clinical and forensic praxis for the rapid and inexpensive\ndetermination of commonly misused groups of biologically active compounds.
Keywords:
analgesics; antidepressants; biologically active compounds
Available on request at various institutes of the ASCR
Determination of Selected Drugs using 3D Printed Electrodes
The main aim of this research was to develop a new method for voltammetric determination of\npopular antidepressants, analgesics, and illicit drugs using a laboratory-made 3D printed\nelectrode and to ...
Application potential of screening in vitro toxicological assays in qualitative risk assessment of nanomaterials
Závodná, Táňa; Topinka, Jan; Danihelka, J.
2020 - English
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.
Keywords:
toxicity; tool; industrial poisons
Available at various institutes of the ASCR
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 ...
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 ...
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. ...
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