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The role of dispersion medium on nanoparticle aggregation and size in biological systems
Červená, Tereza; Rössnerová, Andrea; Závodná, Táňa; Vrbová, Kristýna; Sikorová, Jitka; Topinka, Jan; Rössner ml., Pavel
2020 - anglický
The use of nanomaterials (NMs) in different areas has been rising for more than a decade. Along with this growth, there is visible development of different testing tools and approaches for measuring the actual size of nanomaterials in biological systems. Test conditions during in vitro toxicological assays are different from the standard conditions under which nanomaterials are characterized and careful evaluation of results is needed. The unique properties and range variety of NMs require the close look how the NMs behave in different dispersion medium over time. In this study we present the results of five types of well-characterized NMs (TiO2: NM-101 and NM-103, SiO2: NM-200, Ag: NM-300K and NM-302) of specific size and shape. The hydrodynamic size and Zeta potentials in suspensions were measured using a dynamic light scattering technique (DLS) (Zetasizer Nano ZS, Malvern, UK). The DLS method is suitable for spherical particles, nevertheless, all samples were measured in order to obtain a rough insight into agglomerate formation in the medium. NM300, NM302, and NM200 aggregated rapidly in the media, thus the cells would be most likely exposed to settled big aggregates then small clusters or individual particles. More stable NMs (NM100 and NM103) showed slight grow along with cultivation time or concentration corresponding to cluster formation. Cells exposed to those NMs would be in contact with small clusters and aggregates of NMs. Measured zeta potentials fluctuated around the stability limit corresponding to observed aggregation.
Klíčová slova:
nanomaterials; NMs; DLS; aggregation
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
The role of dispersion medium on nanoparticle aggregation and size in biological systems
The use of nanomaterials (NMs) in different areas has been rising for more than a decade. Along with this growth, there is visible development of different testing tools and approaches for measuring ...
Photon-upconversion nanoparticles for single-molecule immunosensing of cancer biomarkers and bacteria
Farka, Z.; Mickert, M. J.; Hlaváček, Antonín; Poláchová, V.; Kostiv, Uliana; Pastucha, M.; Horák, Daniel; Gorris, H. H.; Skládal, P.
2020 - anglický
The recent progress in the field of immunoassays has been driven by introduction of various kinds of nanomaterials. In particular, photon-upconversion nanoparticles (UCNPs) proved to be excellent immunoassay labels due to their ability to emit light of shorter wavelengths under near-infrared excitation (anti-Stokes emission), which prevents autofluorescence, minimizes light scattering, and thus reduces the optical background interference. These unique photoluminescent properties allow counting of individual biomolecules labeled with UCNPs by conventional wide-field epiluminescence microscopy and enable the development of single-molecule (digital) immunoassays. We have introduced a novel label based on UCNPs conjugated with streptavidin via poly(ethylene glycol) and applied it in a digital upconversion-linked immunosorbent assay (ULISA) for the detection of a cancer biomarker prostate specific antigen (PSA). The digital readout based on counting of individual immunocomplexes improved the sensitivity 16× compared to conventional analog readout and allowed to reach a limit of detection (LOD) of 23 fg·mL−1 (800 aM). Human serum samples were successfully analyzed achieving an excellent correlation with electrochemiluminescence reference method. The conjugates of UCNPs with streptavidin are also suitable for the detection of pathogenic bacterium Melissococcus plutonius, the causative agent of honeybee disease European foulbrood. The ULISA assay provided an LOD of 340 CFU·mL−1 and successfully analyzed real samples of bees, larvae and bottom hive debris. Due to the high reliability and relatively simple detection scheme, the digital ULISA can pave the way for a new generation of digital immunoassays with a strong potential for commercialization.
Klíčová slova:
single-molecule detection; photon-upconversion nanoparticle; bioconjugation
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Photon-upconversion nanoparticles for single-molecule immunosensing of cancer biomarkers and bacteria
The recent progress in the field of immunoassays has been driven by introduction of various kinds of nanomaterials. In particular, photon-upconversion nanoparticles (UCNPs) proved to be excellent ...
Chemical vapor generation of cadmium for analytical atomic spectrometry
Sagapova, Linda; Kodríková, Barbora; Svoboda, Milan; Musil, Stanislav; Kratzer, Jan
2020 - anglický
Chemical vapor generation of cadmium volatile compounds was optimized in order to determine trace Cd concentrations by atomic absorption spectrometry (AAS). Several reaction modifiers based on inorganic salts and complexes of CrIII+, CoII+, TiIII+, TiIV+ were tested to improve analytical performance and generation efficiency.
Klíčová slova:
chemical vapor generation; cadmium; atomic absorption spectrometry
Plné texty jsou dostupné na vyžádání prostřednictvím repozitáře Akademie věd.
Chemical vapor generation of cadmium for analytical atomic spectrometry
Chemical vapor generation of cadmium volatile compounds was optimized in order to determine trace Cd concentrations by atomic absorption spectrometry (AAS). Several reaction modifiers based on ...
Tebuconazole and its behaviour in the presence of magnesium
Jakl, M.; Jaklová Dytrtová, Jana
2020 - anglický
Tebuconazole is a fungicide frequently used in agriculture. Its possible impact to (non-)target species is influenced by its presence. Moreover, the presence of triazoles in soil has an impact to bioavailability of nutrients. This study brings the information potentially useful in the evaluation of tebuconazole fate in the environment. The studies based on the electrospray gas phase experiments provide an estimation of the tebuconazole ability to create complexes with magnesium.
Klíčová slova:
triazoles; Mg(II); mass spectrometry; ESI-MS; complexes
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Tebuconazole and its behaviour in the presence of magnesium
Tebuconazole is a fungicide frequently used in agriculture. Its possible impact to (non-)target species is influenced by its presence. Moreover, the presence of triazoles in soil has an impact to ...
Surface modification of nanoparticles for sustaining sensitivity of surface-enhanced raman spectrometric measurements in salinated environment
Týčová, Anna; Přikryl, Jan; Vaňhara, P.; Klepárník, Karel; Foret, František
2020 - anglický
Surface-enhanced Raman spectrometry (SERS) represents a powerful method for analysis of a broad spectrum of analytes ranging from inorganic ions to biomolecules of high complexity. It combines the potential\nof Raman spectrometry for a definite identification of an analyte with remarkable sensitivity achieved by the surface enhancement effect occurring on metal nanoparticles. While low ionic strength influences positively\nthe sensitivity of the SERS measurement, a higher level of inorganic salts leads to fast ruining of colloidal character, which completely devastates the effect of the surface enhancement. The common stabilization of\nnanoparticles by a layer of polymers has a negative impact on the SERS sensitivity since it shields the nanoparticle surface from the analytes. In this work, we aim at the development of the bi-ligand system of\nnanoparticles surface modification for improved stability of colloid in saline solution at sustaining the potential for sensitive SERS analyses. The proposed system relies on the binding of 3-mercaptopropionic acid and\nthiolated polyethylene glycol in a suitable ratio onto the nanoparticle surfaces. While the short chains of the acid sustain the accessibility of the surface for analytes, the polymeric structures act as a steric barrier\npreventing colloid aggregation.
Klíčová slova:
bi-ligand; nanoparticle; saline solution; surface-enhanced Raman spectrometry
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Surface modification of nanoparticles for sustaining sensitivity of surface-enhanced raman spectrometric measurements in salinated environment
Surface-enhanced Raman spectrometry (SERS) represents a powerful method for analysis of a broad spectrum of analytes ranging from inorganic ions to biomolecules of high complexity. It combines the ...
Historic paint investigation of the Gierczyn parish church painted decoration in the context of the mining history of the region
Svorová Pawełkowicz, Sylwia; Witkowski, M.; Svora, Petr; Wagner, B.
2020 - anglický
The painted decoration of the Gierczyn parish church situated in the Izera Mountains was studied in the context of the rich mining history of the region known for tin, copper, and cobalt ores extraction. Smalt and copper pigments identification is discussed in the context of possible provenance studies. The aim is to determine to what extent the decoration of the parish church in Gierczyn reflects the mining history of the region and to verify whether local materials could have been used. Historic paint investigation is supported by chemical analysis of pigments. Additionally, the paper presents results of research combining archival studies of copper and cobalt extraction, and smalt production in nearby Przecznica, and of the parish church which was the main temple for local miners.
Klíčová slova:
Przecznica (Querbach); Gierczyn (Giehren); mining history; smalt; copper pigments
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Historic paint investigation of the Gierczyn parish church painted decoration in the context of the mining history of the region
The painted decoration of the Gierczyn parish church situated in the Izera Mountains was studied in the context of the rich mining history of the region known for tin, copper, and cobalt ores ...
Forest Soil Physico-Chemical Sorption Spatial Links in Central-European Systems of Site Geographical Divisions
Samec, Pavel; Balková, M.; Kučera, A.
2020 - anglický
Spatial links among soil property values influence variability of soil sorption. The aim of this study was to compare the effect of geotectonic, soil-and biogeographical divisions on forest soil physicochemical sorption spatial links. The effect was investigated through optimal model selection and its comparison among the soil cover division systems of Central-European Highlands in the Czech Republic. Optimal model was selected through the closest-fitting estimations of linear global and local regressions between sorption and chemical or geomorphological forest soil properties. The optimal model comparison was carried out through linear regression with bedrock type proportion (geodiversity) at units of particular division systems. Chemical properties influenced forest soil sorption more than relief. Soil base saturation (BS) was locally more divided than cation exchange capacity (CEC). Local regression of BS with Al2O3 was divided by geotectonic systems the most, but it was not influenced by geodiversity. Geodiversity influenced local regression of CEC with Al2O3 in soil regions as well as regression with C/N in biogeographical regions. Differences between spatial links of BS and CEC suggest that forest soil sorption is divided into multi-level clusters. Spatial link modelling of soil sorption can optimalize forest growth condition division for effective management use.
Klíčová slova:
cation-exchange capacity; organic-matter; weighted regression; resolution; fractions; ratios; soil aluminium; base saturation; geodiversity; geographically weighted regression
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Forest Soil Physico-Chemical Sorption Spatial Links in Central-European Systems of Site Geographical Divisions
Spatial links among soil property values influence variability of soil sorption. The aim of this study was to compare the effect of geotectonic, soil-and biogeographical divisions on forest soil ...
Determination of heavy metal poisoning antidote 2,3-dimercapto-1-propanesulfonic acid using silver solid amalgam electrode
Choińska-Mlynarczyk, Marta; Hrdlička, Vojtěch; Redondo, B. R.; Barek, J.; Navrátil, Tomáš
2020 - anglický
2,3-Dimercapto-1-propane-sulfonic acid (DMPS) was investigated using direct current voltammetry (DCV), differential pulse cathodic stripping voltammetry (DPCSV), differential pulse anodic stripping voltammetry (DPASV), and elimination voltammetry with linear scan (EVLS) at a polished (p-AgSAE)and at a meniscus modified silver solid amalgam electrode (m-AgSAE). EVLS confirmed two consecutive reductions with coupled proton/electron transfer. Voltammetric titrations of DMPS with Pb2+ proved complex formation, with limits of quantification (LOQs) and detection (LODs) 0.3 and 0.1 mu mol L-1 at m-AgSAE and 0.8 and 0.3 mu mol L-1 at p-AgSAE, respectively. Determination of DMPS in commercial drug Dimaval and human urine samples confirmed practical applicability of the developed method.
Klíčová slova:
cathodic stripping voltammetry; 2,3-dimercapto-1-pro-panesulfonic acid; elimination voltammetry with linear scan
Plné texty jsou dostupné na vyžádání prostřednictvím repozitáře Akademie věd.
Determination of heavy metal poisoning antidote 2,3-dimercapto-1-propanesulfonic acid using silver solid amalgam electrode
2,3-Dimercapto-1-propane-sulfonic acid (DMPS) was investigated using direct current voltammetry (DCV), differential pulse cathodic stripping voltammetry (DPCSV), differential pulse anodic stripping ...
Effect of metal sensitizers on photochemical vapor generation of bismuth for analytical atomic spectrometry
Vyhnanovský, Jaromír; Yildiz, D.; Musil, Stanislav
2019 - anglický
Three new sensitizers with a significant positive effect on the photochemical vapor generation of bismuth were described. Cobalt was found to be the most effective and led to a significant enhancement of the signal.
Klíčová slova:
photochemical volatile species generation; bismuth; AAS
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Effect of metal sensitizers on photochemical vapor generation of bismuth for analytical atomic spectrometry
Three new sensitizers with a significant positive effect on the photochemical vapor generation of bismuth were described. Cobalt was found to be the most effective and led to a significant enhancement ...
Adhesion and growth of adipose tissue-derived stem cells on fibrin assemblies with attached growth factors for tissue engineering of heart valves
Filová, Elena; Trávníčková, Martina; Knitlová, Jarmila; Matějka, Roman; Kučerová, Johanka; Riedelová, Zuzana; Brynda, Eduard; Bačáková, Lucie
2019 - anglický
Currently used xenogeneic biological heart valve prostheses are decellularized and crosslinked with glutaraldehyde. These grafts usually undergo degeneration and calcification. Pericardium-based heart valve prostheses, re-seeded with autologous cells, i.e. Adipose tissue-derived cells (ASCs) and endothelial cells, could have longer durability and biocompatibility. In order to improve the adhesion of cells and their ingrowth into decellularized pericardium, various fibrin (Fb) layers were developed, i.e. Fb, Fb with covalently bound heparin (H), Fb with either vascular endothelial growth factor (VEGF) or fibroblast growth factor 2 (FGF) in various concentrations (1 ng/ml, 10 ng/ml, 100 ng/ml) or with both VEGF and FGF (100 ng/ml). Growth factors were attached onto Fb via heparin or were adsorbed. ASCs were seeded on theses layers in a DMEM medium supplemented with 2 % of fetal bovine serum, TGFβ1 and BMP-4 (both 2.5 ng/ml), and with ascorbic acid. Cell adhesion and growth/viability was assessed by counted cell number/MTS evaluation. ASCs were stained for differentiation markers of smooth muscle cells, such as alpha-actin, calponin, and myosin heavy chain. On day 7, ASCs on Fb-H-VEGF layers produced both calponin and alpha-actin. An increased FGF concentration caused reduced calponin staining of ASCs. Lack of heparin in fibrin assemblies with growth factors inhibited the production of both alpha-actin and calponin in ASCs. The highest ASCs density/viability was found on Fb-H-VEGF-FGF layer. The proper formulation of fibrin coatings could be favorable for ASCs growth and differentiation and could subsequently support endothelialization of cardiovascular prostheses with endothelial cells.
Klíčová slova:
adipose tissue-derived stem cells; fibrin assemblies; growth factors; heart valves
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Adhesion and growth of adipose tissue-derived stem cells on fibrin assemblies with attached growth factors for tissue engineering of heart valves
Currently used xenogeneic biological heart valve prostheses are decellularized and crosslinked with glutaraldehyde. These grafts usually undergo degeneration and calcification. Pericardium-based heart ...
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