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Spatially separated HOMO/LUMO at interface of polypyrrole physisorbed on oxidized nanodiamond facets
Matunová, Petra ; Jirásek, Vít ; Rezek, Bohuslav
Nanodiamond particles (NDs) have recently risen in popularity owing to their unique and perspective properties. Merging NDs with organic molecules, such as polypyrrole (PPy), into hybrid organic-semiconductor functional systems gives rise to potential applications in photovoltaics (PV), which is supported by prior experimentally observed charge transfer between bulk diamond and PPy. This work focuses on the most relevant (111) and (100) O-terminated ND facets with different coverage of surface terminating oxygens in ether, epoxide, ketone, and peroxide positions. We use density functional theory (DFT) computations employing B3LYP functional and 6-31G(d) basis set. Energetically the most favorable oxidized ND facets were further optimized with PPy in physisorbed configurations. Analysis of geometry, binding energy, HOMO-LUMO gap, and charge transfer was done on the relaxed PPy-ND structures. Multiple hydrogen bonds are formed between PPy amino groups and O atoms on ND surface.
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Ošetřovatelská péče o pacienta s dg. Ischemická choroba srdeční po operaci
Šedová, Lenka ; Heřmanová, Jana (vedoucí práce) ; Jirásek, Vít (oponent)
Autor práce: Lenka Šedová Vedoucí práce: Mgr. Jana Heřmanová Odborný konzultant: MUDr. Vít Jirásek Téma práce: Ošetřovatelská péče o pacienta s dg. ischemická choroba srdeční po operaci Souhrn: Cílem práce je zpracování případové studie u 79 letého pacienta po kardiochirurgické operaci. Operace byla indikované kvůli ischemické chorobě srdeční. Klinická část práce se zabývá charakteristikou a dělením ICHS. Dále pojednává o diagnostice a léčebných postupech u NAP (nestabilní angína pectoris). V další části práce je popsán průběh hospitalizace pacienta. Poslední část popisuje ošetřovatelský proces u tohoto pacienta, řeší otázku psychologie pacienta a jeho návrat do běžného života. Ošetřovatelská anamnéza je formulována dle modelu Virginie Henderson. Důležitou roli v omezení komplikací hraje edukace. Klíčová slova: ICHS, NAP, ošetřovatelský proces, model V. Henderson, aortokoronární bypass, Warfarin, vyšetřovací metody, soběstačnost, sebepéče
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Calculations of nanocrystalline diamond-covered waveguides based on amorphous silicon
Jirásek, Vít ; Prajzler, Václav ; Remeš, Zdeněk
Nanocrystalline diamond (NCD) coatings on planar waveguides (WG) in the IR region allow to design optical sensors sensitive to absorbers like proteins or other biomolecules. In this contribution, we present a 2D model of a multi-layer WG developed under FEM (finite element method) simulation software Comsol Multiphysics. The model is based on the modified wave equation solved in the frequency domain and includes optical absorption. It was found that for the single-mode WG working in the narrow region of 1550-2000 nm the silicon thickness must be 150-320 nm. It was found that in order to keep a reasonable signal attenuation, the NCD film must be prepared with the optical absorption coefficient lower than 10 cm-1, being a rather challenging task. Dependencies of the signal attenuation on the NCD film thickness, absorbing layer height, its absorption coefficient and exciting wavelengths are presented.\n
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Interpretation of the C=O band of modified diamond nanoparticles by means of DFT theory
Jirásek, Vít ; Kozak, Halyna ; Remeš, Zdeněk ; Kromka, Alexander
Diamond nanoparticles (DNPs) are an interesting class of nanomaterials, which has many unique properties. Their applications in medicine and molecular biology have been mentioned. The DNPs were reviewed in sense of their surface chemistry and a range of analytic techniques was pointed out. The experimental analysis can be enhanced by theoretical models based on the first principles. An approach to theoretical analysis of infrared spectra was introduced. As an example, a part of FTIR spectra of the oxidized DNPs was interpreted by means of the DFT theory. The calculation of the C=O stretch vibrational frequencies of carboxylic and anhydride groups on certain model clusters enabled to explain the shift and splitting of the measured spectral bands.
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