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Frontiers of Polymer Colloids: From Synthesis to Macro-Scale and Nano-Scale Applications. 84th Prague Meeting on Macromolecules. Book of Abstracts
Horák, Daniel
The Book of Abstracts contains the summaries of all the contributions to the international conference “Frontiers of Polymer Colloids: From Synthesis to Macro-Scale and Nano-Scale Applications” was organized simultaneously as the 84th Prague Meeting on Macromolecules (PMM). The participants presented 59 lectures and 38 posters.
Software Design of Single Purpose Machine for Visual Inspection
Horák, Daniel ; Krejsa, Jiří (referee) ; Štarha, Pavel (advisor)
This master’s thesis deals with the fundamentals of machine vision application and its practical implementation. The research part is focused on the basic possibilities of image acquisition and image processing in different dimensions. The practical part describes the design of the dimension control algorithm using a 3D camera. This algorithm is then implemented in a single-purpose machine for optical dimension control.
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.
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.
Low power module with thermocamera
Horák, Daniel ; Najman, Jan (referee) ; Chalupa, Jan (advisor)
This bachelor thesis is focused on contactless temperature measuring with given thermographic camera and lossless image compression obtained by this camera. The theoretical part describes principles for better understanding of the issue and the practical part contains the solution itself, prepared for above mentioned thermographic camera.
Effect of iron oxide nanoparticles with ascorbic acid on neural stem cells
Jiráková, Klára ; Moskvin, Maksym ; Horák, Daniel ; Jendelová, Pavla
Cells labelled with iron oxide nanoparticles (ION) can be tracked by magnetic resonance imaging (MRI) in several applications. However, various studies demonstrated toxicity and oxidative stress induction associated with nanoparticles exposure. We analysed biologic effects after the exposure of two types of iron oxide nanoparticles (with and without an antioxidative agent, an ascorbic acid) on human neural stem cells. The labelled cells in gel phantoms were detected in MRI and they showed decreased relaxation rates in comparison with control. ION slightly decreased cell proliferation in comparison with unlabelled cells, which was dependent on concentration and presence of ascorbic acid. None of the nanoparticle type showed negative effect on cell viability and both demonstrated minor effect on reactive oxygen species (ROS) formation. Unfortunately, ascorbic acid bound to nanoparticles did not show any effect on ROS attenuation. Cells exposed to both types of nanoparticles showed increased positivity for a phosphorylated form of H2AX a marker of double strand breaks. We showed that ION in low concentrations do not affect cell viability, but have negative effect on cells on DNA level. Their potential use for oxidative stress reduction is dependent on the concentration of ascorbic acid bound to the nanoparticles and this should be further increased.
Design and characterization of advanced polymer-coated upconversion nanoparticles
Kostiv, Uliana ; Horák, Daniel (advisor) ; Kaman, Ondřej (referee) ; Brožek, Jiří (referee)
Lanthanide-based upconversion nanoparticles are able to absorb low-energy near-infrared (NIR) photons and emit visible or ultraviolet light. This unique optical property enables luminescent detection without autofluorescence from biological samples that is crucial for bioimaging and diagnostics. Moreover, NIR irradiation allows to deliver light deep into the tissue, which can be used for drug or gene delivery and NIR-induced photodynamic therapy (PDT) of tumors. Despite huge effort during the last 10 years devoted to the upconversion nanoparticle synthesis and their surface engineering, preparation of the particles suitable for biomedical applications still remains a big challenge. The current work is focused on synthesis of the upconversion nanoparticles with controllable morphology, size, distribution, crystallinity, and high upconversion efficiency, as well as on desirable surface modification by biocompatible inorganic or organic polymers. Neat and functionalized homogeneous silica shell was introduced on the NaYF4:Yb3+ /Er3+ and NaGdF4:Yb3+ /Er3+ nanoparticles to enhance their biocompatibility and colloidal stability in water. To render the nanoparticles with targeting moieties, their surface was decorated with cell-adhesive RGD or cell-penetrating TAT peptides. The RGD- and TAT- conjugated...
Preparation of uniform superparamagnetic particles with polymer coating for biomedical applications
Patsula, Vitalii ; Horák, Daniel (advisor) ; Sysel, Petr (referee) ; Matějíček, Pavel (referee)
Aim of this thesis was to design and prepare polymer-coated monodisperse Fe3O4 nanoparticles as a safe and non-toxic contrast agent for magnetic resonance imaging (MRI) and heat mediator for hyperthermia. Uniform superparamagnetic Fe3O4 nanoparticles were synthesized by thermal decomposition of Fe(III) oleate, mandelate, or glucuronate in high- boiling solvents at temperature >285 řC. Size of the particles was controlled in the range of 8- 27 nm by changing reaction parameters, i.e., temperature, type of iron precursor, and concentration of stabilizer (oleic acid and/or oleylamine), while preserving uniformity of the nanoparticles. Because particles contained hydrophobic stabilizer on the surface, they were dispersible only in organic solvents. To ensure water dispersibility, oleic acid on the particle surface was replaced by hydrophilic and biocompatible methoxy-poly(ethylene glycol) (PEG) and poly(3-O-methacryloyl-α-D-glucopyranose) by ligand exchange. Polymers were previously terminated with anchoring-end groups (hydroxamic or phosphonic) to provide firm bonding to iron atoms on the particle surface. Fe3O4 nanoparticles were also hydrophilized by encapsulation into a silica shell by reverse microemulsion method. Tetramethyl orthosilicate was used to prepare Fe3O4@SiO2 nanoparticles, which were...
The use of real time PCR method for evaluation of magnetic microspheres
Trachtová, Š. ; Rittich, B. ; Horák, Daniel ; Španová, A.
The real-time quantitative PCR (qPCR) was used for the evaluation of non-porous HEMA-based magnetic microspheres on the PCR course (PCR sensitivity). It was shown that 1-10 mu l microsphere suspensions (2 mg/ml) in PCR mixtures do not interfere in the PCR. It can be assumed that the magnetic nuclei were covered with polymer layer.
Superparamagnetic nano- and microparticles with hydrophilic surfaces
Babič, Michal ; Horák, Daniel (advisor) ; Šňupárek, Jaromír (referee) ; Šafařík, Ivo (referee)
This work deals with a preparation of superparamagnetic nano- and microparticles with hydrophilic surfaces for bioapplications. The wok is divided into three parts in consonance with experimentally solved problem. First part describes a choice and an optimalization of synthesis of iron oxides nanoparticles with appropriate toxicological, morphological and physico-chemical properties, which surface can be post synthetically modified. Maghemite - γ-Fe2O3 particles were prepared by consequent oxidation of mangnetite - Fe3O4 as an initial substance for a preparation of materials for diagnostics and separations. A conventional alkaline coprecipitation method of magnetite preparation was modified to produce nanoparticles with narrowed size distribution without use of surfactants during their synthesis. Prepared maghemite nanoparticles were cca. 6 nm in diameter and their saturation magnetization was Ms ~ 70 A·m2 ·kg-1 . Such observed value is far higher in comparison with the state of the art and argues thus a proposition the Ms depends not on the preparation method, but only on the nanoparticles size. Maghemite nanoparticles morphology was evaluated by picture analysis of SEM and TEM micrographs, hydrodynamic size and zetapotential was measured with DLS. The structure of the maghemite was confirmed with...
Preparation and characterization of superparamagnetic inorganic/polymer particles for biomedical application
Zasońska, Beata Anna ; Horák, Daniel (advisor) ; Šafařík, Ivo (referee) ; Sysel, Petr (referee)
Superparamagnetic -Fe2O3 nanoparticles were synthesized by coprecipitation of ferric and ferrous salts with a base. Resulting nanoparticles were coated with shells, such as poly(N,N- dimethylacrylamide) (PDMAAm), neat and functionalized silica (SiO2 and SiO2-NH2), and polyaniline (PANI). PDMAAm shell was introduced by modification of iron oxide nanoparticle surface with an initiator and N,N-dimethylacrylamide was polymerized producing -Fe2O3&PDMAAm core-shell particles. In case of SiO2-NH2 shell, tetramethyl orthosilicate was used to yield -Fe2O3&SiO2 nanoparticles, which were subsequently modified by (3-aminopropyl)triethoxysilane to prepare γ-Fe2O3&SiO2-NH2 particles. Oxidation of aniline hydrochloride with ammonium persulfate in an aqueous solution of poly(N-vinylpyrrolidone) in the presence of iron oxides produced -Fe2O3&PANI nanoparticles. Finally, the last type of the particles was based on thionin-modified poly(carboxymethyl methacrylate) (PCMMA&Th). The particles were characterized by techniques, such as scanning and transmission electron microscopy (SEM and TEM) and dynamic light scattering (DLS) to determine the particle morphology and hydrodynamic diameter. The presence of the functional groups, chemical composition, and the iron content were investigated by Fourier-transform...

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See also: similar author names
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1 Horák, D.
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8 Horák, David
2 Horák, Dominik
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