No (461)
Used filters
(2)
Number of found documents:
461
Published from
to
Labile Lead Phytochelatin Complexes Could Enhance Transport of Lead Ions across Biological Membrane
Šestáková, Ivana; Navrátil, Tomáš
2017 - English
In connection with studies of hazardous metals transport across model phospholipid\nmembranes, behavior of complexes of lead with phytochelatin PC2 has been examined. Using\nstripping chronopotentiometry with different values of reducing current, the release of free\nlead ions confirms labile behavior. Similar conclusion resulted from voltammetry on silica gel\nmodified carbon paste electrode.
Keywords:
phytochelatin; lead; voltammetry
Available on request at various institutes of the ASCR
Labile Lead Phytochelatin Complexes Could Enhance Transport of Lead Ions across Biological Membrane
In connection with studies of hazardous metals transport across model phospholipid\nmembranes, behavior of complexes of lead with phytochelatin PC2 has been examined. Using\nstripping ...
Charge Transport in Single Molecule Junctions of Spirobifluorene Scaffold
Hromadová, Magdaléna; Kolivoška, Viliam; Sokolová, Romana; Šebera, Jakub; Mészáros, G.; Valášek, M.; Mayor, C.
2016 - English
Single molecule conductance of two spirobifluorene molecules of different length have been studied by scanning tunneling break junction (STM–BJ) methodology. First molecule contains a tripodal spirobifluorene platform, whereas a second one contains the same platform with chemically attached p-phenyleneethynylene molecular wire. The conductance values change only slightly between these two molecules, which demonstrated that such a platform provides both highly conducting pathway and stable anchor for the future molecular electronic devices.
Keywords:
single molecule conductance; spirobifluorene; break junction
Available at various institutes of the ASCR
Charge Transport in Single Molecule Junctions of Spirobifluorene Scaffold
Single molecule conductance of two spirobifluorene molecules of different length have been studied by scanning tunneling break junction (STM–BJ) methodology. First molecule contains a tripodal ...
Fosfolipidy modifikovaná elektroda ze skelného uhlíku a její využití pro stanovení pesticidů
Švecová, H.; Sokolová, Romana; Součková, J.; Skopalová, J.; Barták, P.
2016 - Czech
Lipidové membrány jsou již mnoho let studovány jako modely biomembrán. Formování lipidových membrán na povrchu pevných elektrod poprvé popsali Tien a Salamon 1. Od té doby byly použity jako substráty pro lipidové vrstvy různé materiály jako např. stříbro 2, zlato 3, rtuť 4 nebo skelný uhlík 5. Lipidový film na povrchu elektrody je schopen akumulovat organické molekuly v závislosti na jejich náboji a na jejich hydrofilním respektive hydrofobním charakteru. Je známé, že mnoho organických látek, jako jsou pesticidy, léčiva a jiné farmakologicky významné látky, interagují s fosfolipidovou vrstvou a mastnými kyselinami v membráně a mohou být silně akumulovány v lipidové tkáni. In this article we described glassy carbon electrode modified with Asolectin (mixture of phosholipids). Properties of phospholipid layer, such as its thickness or solidity, were investigated using atomic force microscopy (AFM). The modified electrode was applied for square wave voltammetry (SWV) measurements to study interactions of pesticide paraquat with phospholipid layer and to detect paraquat selectively in real samples of river water.
Keywords:
paraquat; electrochemistry; phospholipids
Available at various institutes of the ASCR
Fosfolipidy modifikovaná elektroda ze skelného uhlíku a její využití pro stanovení pesticidů
Lipidové membrány jsou již mnoho let studovány jako modely biomembrán. Formování lipidových membrán na povrchu pevných elektrod poprvé popsali Tien a Salamon 1. Od té doby byly použity jako substráty ...
Využití voltametrické metody pro sledování obsahu antioxidantu v biopalivech
Tomášková, M.; Chýlková, J.; Navrátil, Tomáš; Šelešovská, R.
2016 - Czech
Z hlediska kvality biopaliv je hlavním problémem jejich oxidační degradace během skladování, která vede ke vzniku produktů, které mohou způsobit ucpání palivových filtrů nebo korozi kovových částí motoru. Kromě toho má oxidační stabilita běžné motorové nafty podstatný vliv na stabilitu směsí s bionaftou. Právě nestabilita bionafty v porovnání s běžně používanou naftou vede k řadě otázek a obav při skladování biopaliv. Pro zpomalení oxidace a zajištění dostatečné stability je nutné nalézt vhodná aditiva a znát jejich přesné množství. Mezi antioxidanty používané pro zvýšení oxidační stability bionafty a jejich směsí s běžnou naftou patří i propyl galát 1-4. The simple and fast method for analysis of Propyl gallate (PG) in biofuels was proposed in this paper. Voltammograms of antioxidant under study were recorded using linear sweep voltammetry method at a gold disc electrode in supporting electrolyte containing 0.18 mol L-1 H2SO4 and 10 % ethanol. For purposes to monitor effects on fuel quality caused by oxidative degradation, the proposed method was applied to samples of biodiesel and Ekodiesel® (the blend of biodiesel with fuel diesel). The analysis of PG can be performed without pretreatment of Ekodiesel samples, and after extraction using distilled water in case of biodiesel samples.
Keywords:
propyl gallate; antioxidant; voltammetry
Available at various institutes of the ASCR
Využití voltametrické metody pro sledování obsahu antioxidantu v biopalivech
Z hlediska kvality biopaliv je hlavním problémem jejich oxidační degradace během skladování, která vede ke vzniku produktů, které mohou způsobit ucpání palivových filtrů nebo korozi kovových částí ...
Graphene Field-Effect Transistor as a Probe of Doping by Adsorbed Oxygen Molecules
Blechta, Václav; Mergl, Martin; Drogowska, Karolina; Kučera, Lukáš; Valeš, Václav; Červenka, Jiří; Kalbáč, Martin
2016 - English
Graphene has high potential in chemical sensing, thus understanding adsorption and charge transfer between graphene and adsorbed molecules is essential. We show that graphene field-effect transistor exhibits a moderate sensoric response towards oxygen at temperature of 150 °C. Field-effect transistors serve as a tool to probe electronic properties of graphene. We demonstrate that adsorption of oxygen molecules onto graphene leads to an upshift of Dirac point and light changes in mobility of charge carriers.
Keywords:
graphene; sensor; transistor
Available at various institutes of the ASCR
Graphene Field-Effect Transistor as a Probe of Doping by Adsorbed Oxygen Molecules
Graphene has high potential in chemical sensing, thus understanding adsorption and charge transfer between graphene and adsorbed molecules is essential. We show that graphene field-effect transistor ...
Voltammetric determination of homovanillic acid at boron doped diamond electrode for hollow fibre microextraction
Hrdlička, V.; Barek, J.; Navrátil, Tomáš
2016 - English
Presented work deals with hollow-fibre assisted liquid/liquid/liquid microextraction (HF-LPME) and subsequent voltammetric detection of clinical biomarker homovanillic acid (HVA). Three main areas are discussed: hollow fibre assisted extraction of HVA, voltammetric detection of HVA under basic conditions, and sensing in very small volumes. Using HF-PLME, HVA was extracted with 1-octanol as a supported liquid membrane with enrichment factor of 55 after 60 minutes of extraction. A novel method of miniaturized voltammetric determination of HVA using cathodically pretreated boron doped diamond electrode was also developed. Using differential pulse voltammetry, limit of detection, limit of quantificati was 1.9 mu mol dm(-3) on 6.6 mu mol dm(-3).
Keywords:
biomarkers; boron doped diamond electrode; hollow-fibre
Available at various institutes of the ASCR
Voltammetric determination of homovanillic acid at boron doped diamond electrode for hollow fibre microextraction
Presented work deals with hollow-fibre assisted liquid/liquid/liquid microextraction (HF-LPME) and subsequent voltammetric detection of clinical biomarker homovanillic acid (HVA). Three main areas are ...
Redakčně upravená závěrečná zpráva projektu DF11P01OVV012: Nové materiály a technologie pro konzervaci materiálů památkových objektů a preventivní památkovou péči
Rathouský, Jiří; Slížková, Zuzana; Kotlík, P.
2016 - Czech
Projekt byl zaměřen na vývoj nových materiálů a technologií pro komplexní řešení problematiky uchování hodnot hmotného kulturního dědictví v ČR zejména s ohledem na čištění historických materiálů s využitím mikroemulzí a micelárních roztoků, konsolidaci objektů pomocí nanodisperzí hydroxidu vápenatého a modifikovaných ethylsilikátových gelů a preventivní ochranu materiálů proti působení vnějšího prostředí a biokorozi, včetně zachování jejich původního vzhledu. This project was focused on development of new materials and technologies for complex solution of problems with preservation of a cultural heritage in the Czech Republic. Main interests were conservation activities as cleaning of historical materials using microemulsions and micellar solutions, consolidation by calcium hydroxide and modified ethylsilicate gels and protection of materials against environment effects and biocorrosion, including protection of the original appearance of the historic materials.
Keywords:
consolidation; cleaning of historical materials; protection
Available on request at various institutes of the ASCR
Redakčně upravená závěrečná zpráva projektu DF11P01OVV012: Nové materiály a technologie pro konzervaci materiálů památkových objektů a preventivní památkovou péči
Projekt byl zaměřen na vývoj nových materiálů a technologií pro komplexní řešení problematiky uchování hodnot hmotného kulturního dědictví v ČR zejména s ohledem na čištění historických materiálů s ...
Electrochemical determination of 2-nitrofluorene and investigation of its interaction with DNA
Skalová, Štěpánka; Stávková, K.; Barek, J.; Vyskočil, V.
2016 - English
2-Nitrofluorene (2-NF) belongs to the group of nitrated polycyclic aromatic hydrocarbons. These compounds are categorized as environmental pollutants and they can manifest mutagenic and carcinogenic effects. A differential pulse voltammetric method at a glassy carbon electrode (GCE) was developed for sensitive determination of 2-NF. Under the optimum conditions found, a linear calibration dependence was obtained in the concentration range of 2 x 10(-7) - 1 x 10(-5) mol L-1, with the limit of quantification of 2 x 10 mol L-1. The practical applicability of this method was verified on the direct determination of 2-NF in a model sample of sand. Moreover, the mutual interaction between 2-NF and DNA was investigated using an electrochemical DNA biosensor (DNA-modified GCE). Cyclic voltammetry, electrochemical impedance spectroscopy, and square-wave voltammetry were employed in this study, confirming the formation of a 2-NF-DNA complex.\n
Keywords:
DNA biosensors; DNA interaction; glassy carbon electrode
Available at various institutes of the ASCR
Electrochemical determination of 2-nitrofluorene and investigation of its interaction with DNA
2-Nitrofluorene (2-NF) belongs to the group of nitrated polycyclic aromatic hydrocarbons. These compounds are categorized as environmental pollutants and they can manifest mutagenic and carcinogenic ...
THE PHOTOCATALYTIC ABATEMENT OF NOX IMISSIONS USING COMMERCIAL FUNCTIONAL COATING WITH POROUS MORPHOLOGY
Žouželka, Radek
2016 - English
Titanium dioxide is the most important photocatalysts used for purifying applications. It was the purpose of this study to investigate the photocatalytic activity of commercial Protectam FN (R) containing TiO2 nanoparticles towards NO and NO2. Experiments on concrete as a support for photocatalyst were carried out in two types of reactors with laminar and turbulent flow under ´´real world setting´´ conditions of temperature, relative humidity, irradiation and pollutant concentrations. The results showed that photocatalytic process significantly reduced both nitrogen oxides in the air. The decrease in the total concentration of nitrogen oxides on contact with the photocatalytic surface reached 20-50 %, i.e. at a concentration of 100 ppb the decrease in NO and NO2 was 20-50 ppb. The nitrogen oxides were oxidized up to their highest oxidation state, nitric acid ( or nitrates) and undesirable nitrous acid was not formed at all. The experimental study conducted showed that the photocatalytic oxidation on the surface of the photocatalytic Protectam FN (R) coating is an effective method for the removal of nitrogen oxides from contaminated air.
Keywords:
TiO2; NOx; imissions; photocatalysis; air purification
Available at various institutes of the ASCR
THE PHOTOCATALYTIC ABATEMENT OF NOX IMISSIONS USING COMMERCIAL FUNCTIONAL COATING WITH POROUS MORPHOLOGY
Titanium dioxide is the most important photocatalysts used for purifying applications. It was the purpose of this study to investigate the photocatalytic activity of commercial Protectam FN (R) ...
Possibilities of Hollow Fiber Microextraction and Voltammetric Detection of Homovanillic acid
Hrdlička, V.; Barek, J.; Navrátil, Tomáš
2016 - English
The contribution deals with hollow fiber liquid phase microextraction (HF-LPME) of homovanillic acid (HVA) and its subsequent voltammetric detection. In HF-LPME, HVA is extracted from acidic sample through thin supported liquid membrane into basic aqueous acceptor solution. Since common electrode materials such as gold, platinum or glassy carbon are only able to detect HVA under acidic or neutral conditions, a new method was developed, utilizing silica gel modified carbon paste electrode (CPE). Reached limit of detection in a 10 μL drop of the HVA extract of pH 13 was 1·10-5 mol L-1.
Keywords:
Hollow-fibers; Liquid phase microextraction; voltammetry
Available at various institutes of the ASCR
Possibilities of Hollow Fiber Microextraction and Voltammetric Detection of Homovanillic acid
The contribution deals with hollow fiber liquid phase microextraction (HF-LPME) of homovanillic acid (HVA) and its subsequent voltammetric detection. In HF-LPME, HVA is extracted from acidic sample ...
NRGL provides central access to information on grey literature produced in the Czech Republic in the fields of science, research and education. You can find more information about grey literature and NRGL at service web
Send your suggestions and comments to nusl@techlib.cz
Provider
Other bases