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Comparison of the Covalent Laccase Immobilization at Amino- and Carboxylfunctionalized Mesoporous Silica, Glassy Carbon, and Graphite Powders using Different Coupling Agents for Optimal Biosensor Preparation
Tvorynska, Sofiia; Barek, J.; Josypčuk, Bohdan
2021 - anglický
In order to find the most suitable immobilization protocol, a comparison of three strategies\nbased on the application of –NH2 and –COOH functionalized supports with the different\nactivation agents (glutaraldehyde and carbodiimide) have been conducted for the covalent\nenzyme (laccase) attachment. Two kinds of the supports, namely mesoporous silica (SBA−15,\nMCM−41) and carbonaceous (glassy carbon, graphite) powders, have been used. It was found\nthat a biosensor consisted of tubular detector of silver solid amalgam as a working electrode\nand the enzymatic mini-reactor with laccase covalently attached to glutaraldehyde activated\n–NH2 functionalized MCM−41 shows the best results regarding sensitivity and stability for\ndopamine detection.
Klíčová slova:
Covalent enzyme immobilization; Support surface functionalization; Laccase
Plné texty jsou dostupné na vyžádání prostřednictvím repozitáře Akademie věd.
Comparison of the Covalent Laccase Immobilization at Amino- and Carboxylfunctionalized Mesoporous Silica, Glassy Carbon, and Graphite Powders using Different Coupling Agents for Optimal Biosensor Preparation
In order to find the most suitable immobilization protocol, a comparison of three strategies\nbased on the application of –NH2 and –COOH functionalized supports with the different\nactivation agents ...
EPR/UV-VIS-NIR Spectroelectrochemical Examination of the Association Properties of Thienoacene-Bridged Tetrathiafulvalenes Supported by DFT Calculations
Lušpai, Karol; Rapta, P.; Zalibera, M.; Darvasiová, D.; Lukeš, V.
2021 - anglický
This work was focused on the EPR/UV-VIS-NIR spectroelectrochemical examination of\nassociation properties of radical cations electrochemically produced from tetrathiafulvalene\n(TTF) derivatives, in relation to the molecular structure, mainly the number and orientation of\nthiophene rings in the spacer between fulvalene redox centers. Results from EPR/UV-VIS-NIR\nspectroelectrochemistry were supported by DFT calculations.
Klíčová slova:
Tetrathiafulvalene; EPR/UV-VIS-NIR spectroelectrochemistry; Cyclic voltammetry
Plné texty jsou dostupné na vyžádání prostřednictvím repozitáře Akademie věd.
EPR/UV-VIS-NIR Spectroelectrochemical Examination of the Association Properties of Thienoacene-Bridged Tetrathiafulvalenes Supported by DFT Calculations
This work was focused on the EPR/UV-VIS-NIR spectroelectrochemical examination of\nassociation properties of radical cations electrochemically produced from tetrathiafulvalene\n(TTF) derivatives, in ...
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 - anglický
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.
Klíčová slova:
Copper complexes; Catechol; spectroelectrochemistry
Plné texty jsou dostupné na vyžádání prostřednictvím repozitáře Akademie věd.
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 - anglický
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.
Klíčová slova:
hyperspectral; machine learning; remote sensing; winter wheat; yield
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
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 - anglický
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.
Klíčová slova:
epitachophoresis; isotachophoresis; preparative concentration
Plné texty jsou dostupné na vyžádání prostřednictvím repozitáře Akademie věd.
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 - anglický
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.
Klíčová slova:
caspase; fluorescence; quantum dot
Plné texty jsou dostupné na vyžádání prostřednictvím repozitáře Akademie věd.
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 - anglický
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.
Klíčová slova:
ion transfer voltammetry; electrochemical detection; ionic liquid
Plné texty jsou dostupné na vyžádání prostřednictvím repozitáře Akademie věd.
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 - anglický
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.
Klíčová slova:
boron-doped diamond electrode; 5-hydroxyindoleacetic acid; square wave voltammetry
Plné texty jsou dostupné na vyžádání prostřednictvím repozitáře Akademie věd.
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 - anglický
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.
Klíčová slova:
analgesics; antidepressants; biologically active compounds
Plné texty jsou dostupné na vyžádání prostřednictvím repozitáře Akademie věd.
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 ...
Rozdíly v elektrochemické redukci jedno- a vícejaderných acylgermanů
Liška, Alan; Frühwirt, P.; Haas, M.; Ludvík, Jiří; Gescheidt-Demmer, G.
2021 - český
Acylgermany představují pestrou třídu organoprvkových sloučenin, které se vyznacuJI\npozoruhodnými fotochemickými vlastnostmi, laditelnými zavedením různých typů periferních\nsubstituentů, jejich počtem, polohou, případně způsobem přemostění. Většina známých\nderivátů podléhá vlivem DV-záření nebo dokonce krátkovlnějšího viditelného světla\nhomolytickému štěpení vazby C-Ge za vzniku radikálů. Některé (např. Ivocerin®) se proto již\ndelší dobu používají v zubní medicíně jako fotoiniciátory polymerizace při přípravě bílých\nnetoxických zubních výplní. Příslušné mechanismy reakcí uplatňujících se v praxi jsou v\nliteratuře dobře dokumentovány. Vzhledem k tomu, že penetrační hloubka\nelektromagnetického záření je nepřímo úměrná jeho energii, existuje snaha nalézt další\nderiváty, které budou efektivně štěpeny světlem o co největší vlnové délce. Kromě absorpčních\nspekter a teoretických výpočtů molekulových vlastností (ionizační energie, elektronové\nafinity) se při hledání nových látek s výhodou uplatňují elektrochemické metody, protože\npoloha prvního redukčního potenciálu (resp. rozdíl mezi prvním redukčním a prvním\noxidačním potenciálem) koreluje se schopností molekuly absorbovat světlo a zaujímat vyšší\nexcitované stavy, což se projeví jako poloha dlouhovlnného pásu UV-vis spekter. Ail the studied compounds accept first electron under formation a stable anion radical. The\ncorresponding reduction potentials in aprotic media depend on electronic (inductive,\nmesomeric) properties of the substituents, their number, and position. Here, aromatic acyl group\n(benzoyl group with various substitution on aromatic ring) is the principal substituent. The\nredox properties of presented organoelement compounds with central heteroatom Ge (Si, Sn)\nare controlled by peripheral carbonyl groups (in role of redox centers), their number, and\naromatic ring substitution. The measured first reduction potentials E1 values are found in wide\nrange (> 900 mV) due to the fact that the redox centers are carbony 1 groups connected through\nheteroatom in case of acylgermanes, while for di- and trinuclear derivatives (which are\nmolecules with multiple redox centers) the easiest reducible center is the bridging aromatic unit\ninfluenced by the closest carbonyl groups. Thus, it is possible to distinguish both groups ofnonequivalent\ncarbonyl substituents.
Klíčová slova:
Acylgermanes; Electrochemistry; Voltammetry
Plné texty jsou dostupné na vyžádání prostřednictvím repozitáře Akademie věd.
Rozdíly v elektrochemické redukci jedno- a vícejaderných acylgermanů
Acylgermany představují pestrou třídu organoprvkových sloučenin, které se vyznacuJI\npozoruhodnými fotochemickými vlastnostmi, laditelnými zavedením různých typů periferních\nsubstituentů, jejich ...
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