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Characterization of upconversion nanoparticles by fluorescence spectrometry and capillary electrophoresis
Vaněčková, T. ; Zítka, J. ; Hlaváček, Antonín ; Adam, V. ; Vaculovičová, M.
Upconversion nanoparticles (UCNPs) are a novel class of luminescent tags for applications in life and material sciences. Unlike traditional fluorophores, UCNPs exhibit emission of shorter wavelength under near-infrared excitation (typically 980 nm). In this work, we have examined these unique photophysical properties by fluorescence spectrometry and capillary electrophoresis. UCNPs co-doped with Yb(III) and Er(III) were characterized using laboratory-made fluorescence spectrometer. We have exploited and evaluated two excitation sources and the dependence of the fluorescence of UCNPs on the relative excitation power. Moreover, capillary electrophoresis with laser-induced fluorescence (CE-LIF) detection was for the first time used for characterization of the nanoparticles. It was proved that CE-LIF is a valuable method to be used for investigation of upconversion luminiscence and monitoring of the interactions of UCNPs with other molecules of interest.
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Effect of artificially induced drought on growth and productivity of selected crops within field experiment in Bohemian-Moravian highlands
Wimmerová, Markéta ; Hlavinka, Petr ; Trnka, Miroslav ; Žalud, Zdeněk ; Pohanková, Eva
The field experiments based on manipulating the crop environment are critical for determining the crop’s response to the climatic conditions expected in the future. An experimental site in Domanínek is located by 49°31'42 N, 16°14'13 E at an altitude of 560 m (potato production area). The field experiment using rain-out shelters for soil water availability reduction was conducted in 2015/2016. The main aim of this study was to assess the impacts of different water availability (rain-out shelters vs. control) on the performance of selected field crops (spring barley, winter wheat, winter rape and silage maize). Reduction of precipitation in treatment with rain-out shelters was confirmed by measuring soil water content. The amount of precipitation during growing period was reduced by 251 mm, 277 mm, 217 mm and 240 mm for the spring barley, winter wheat, winter rape and silage maize, respectively. As a consequence, leaf area index and yields declined, however the crop responses were not consistent.
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