National Repository of Grey Literature 32 records found  beginprevious12 - 21nextend  jump to record: Search took 0.01 seconds. 
Vliv probiotik na imunologické vlastnosti buněk obranného systému
Šustrová, Tereza
This disertation thesis aims to determine the effect of probiotic on the cells of immune system – human, procine and rat neutrophils and macrophages. Immune cells were exposed to 3 probiotics – Bifidobacterium bifidum, Lactobacillus rhamnosus and Enterococcus faecium, which are normally included in GIT. The first aim of this study was choose the most appropriate method for the isolation of human and porcine neutrophils and PBMC from peripheral blood. Other aims were to find out whether interactions of probiotics with neutrophils and macrophages affect their lifetime and lead to their structural changes. And whether intraperitoneal administration of probiotics lead to pro-inflammatory polarizoation of macrophages and affect viability of intraperitoneal immune cells. Structural changes of cells were detected by light and transmission electron microscopy. For detection of early and late apoptosis was used flow cytometry and for detection od cytolysis was used LDH aktivity. To determine of effect of probiotics on polarization of rat macrophages, qRT PCR was used. The results of this thesis suggest that all tested probiotics led to a significant increase in early apoptosis in porcine neutrophils and late apoptosis and cytolysis (LDH) in human neutrophils in vitro.
Analýza tvorby buněk sekundárního xylému a floému borovice lesní (Pinus sylvestris L.) v reakci na stres suchem
Fajstavr, Marek
Scots pine (Pinus sylvestris L.) is a long-term economically preferred woody species not only from the standpoint of its wood production but also thanks to its tolerance to extreme climatic factors, environmental modesty, and resistance to drought stress. In recent years, however, due to the action of the changing climatic conditions, this economically significant woody species withers. Its increment in the natural ecotype is affected by the adaptability to the increasing intensity of temperature extremes (prolonged heat waves). The combination of the lack of precipitation and extremely high air temperatures (even in the spring season) will significantly affect the resistance of this woody species to drought stress. This thesis is focused on the analysis of the secondary xylem and phloem cells formation of Scots pine depending on the physiological and morphological changes due to the affecting drought stress. Within the scope of the forming radial cells in individual growing seasons (2013–2016), it has been evaluated how the synergy of the specific factors affecting the overall anatomic structure of the annual ring and the vitality of the examined woody species was expressed in the formation, differentiation, and overall structure of the cells. During the four growing seasons (2013–2016), micro-cores (diameter 1.8 mm) were taken in weekly intervals in the research area in Sobesice of xylem and phloem (including the cambial zone) using the Trephor increment borer. From these micro-cores, permanent microscopic slides of the cross-section were made, on which the analysis of the cambial activity, cell formation, cell differentiation with time, and the evaluation of the morphometric parameters of the formed of xylem and phloem cells were performed. It was found that in each monitored growing season, the drought stress has shown, which was reflected by the dropped of the soil water potential (below -1 MPa) and the intensity of transpiration, which led to the stress reaction of the cambium. The reaction of the drought-stressed cambial zone has been expressed by the decreased activity (a sudden drop of the number of dividing cells) and subsequently, during the recurrence of precipitation, by the reactivation when an increase of the number of dividing cells was observed again. This factor initiated the formation of the intra-annual density fluctuations (IADF), i.e. the formation of the so-called false annual ring. The sensitive reaction of the cambium to the drought stress affected the cell production time, the number of formed cells, and also the time of differentiation of individual tracheids, which was expressed by the reduction of the radial dimensions and cell wall thickness of the tracheids. The artificially induced stress by stem girdling intensified the concurrent drought factor and in the area below the girdling, the cambial activity has stopped within two weeks after the performed treatment. The formed cells were not fully differentiated, so the zone of typically thick-walled cells of latewood was missing in the annual ring. The following growing season, the radial increment was only formed in the area above the girdling (without the latewood zone) and in the second half of the growing season, the trees gradually died. The activity of the plant hormone IAA was also affected by the drought in the summer season, when its concentration dropped below the measurability threshold (2 µg sample-1). At the time of the IAA concentration drop, latewood tracheids began to form and the phloem cell formation was completed. The synthesis and activity of the soluble low-molecular carbohydrates correlated with the course of the cambial activity and the cell differentiation phases, where the dynamics of the concentration also matched the timing of the formation of the individual cell formation phases. With phloem cells, a significant variability in the morphological dimensions has not been observed compared to xylem cells. The phenology of the needles indicated the cell wall formation phases and the initiation of the latewood tracheids. Due to the fact that the needles were fully formed in the season of the spring tracheids formation, their phenology did not reflect the drought stress which was recorded mainly in the summer season. Also, the increment of phloem was formed in the spring season. It has been presented for a long time that coniferous woody species react to the drought stress by thicker cell walls formation of the latewood tracheids. However, it has been observed within the scope of the research of this thesis that the water deficit affected the cambial activity, which has expressed itself on the intensity of the cell formation and the time of their differentiation. Due to this process, tracheids with smaller radial dimensions and a narrower cell wall were formed. This gradually causes structural changes of the formed annual ring, where the typically earlywood and latewood tracheids (classified according to radial dimensions and thicknesses of cell walls) may form independently on the growth seasonality. Especially in cases of IADF formation or in combination with the case where latewood is not even formed, a problem with the validity of the classification according to the so-called Mork’s criterion begins to occur. The understanding of the effect of the specific metabolic and physiological changes on xylem and phloem formation of Scots pine helps to clarify the issues of forestation and overall wood production of this economically significant woody species.
Cell detection using convolutional neural networks
Doskočil, Ondřej ; Chmelík, Jiří (referee) ; Vičar, Tomáš (advisor)
This bachelor thesis deals with the use of convolutional neural networks for cell detection in image data. The theoretical part contains a description of the functioning of these networks and their various architectures. In the practical part, these networks were implemented and trained on an available dataset. However, each of these networks uses a different approach to detection. Finally, the individual networks were statistically evaluated and a discussion was conducted.
Electronic effects at the interface between biomolecules, cells and diamond
Krátká, Marie ; Rezek, Bohuslav (advisor) ; Cifra, Michal (referee) ; Skládal, Petr (referee)
Understanding and control of interactions between biological environment (cells, proteins, tissues, membranes, electrolytes, etc.) and solid-state surfaces is fundamental for biomedical applications such as bio-sensors, bio-electronics, tissue engineering and implant materials as well as for environmental monitoring, security and other fields. Diamond can provide unique combination of semiconducting, chemical, optical, biocompatible and other properties for this purpose. In this thesis we characterize electronic properties of protein-diamond interface by employing a solution-gated field-effect transistor (SGFET) based on hydrogen-terminated diamond, surface of which is exposed to biological media. We elucidate the role of adsorbed protein layer on the electronic response of the diamond transistor. We investigate effects of cells (using mainly osteoblast cells as model) on diamond SGFETs transfer characteristics and gate currents. We employ nanocrystalline diamond (NCD) thin films of different grain sizes (80 - 250 nm) to characterize and discuss influence of grain boundaries and sp2 phase on bio- electronic function of SGFETs. We investigate effects of gamma irradiation on function and stability of hydrogen-terminated diamond SGFETs interfaced with proteins and cells, showing feasibility of...
Atomic force microscopy in the region of biomacromolecules
Vančura, Martin ; Kopecký, Vladimír (advisor) ; Bednárová, Lucie (referee)
Atomic force microscopy (AFM) enables sample imaging at the micro and nanoscale. Recently, the method is applied to investigate biomacromolecules. Here, we describe the basic principles of AFM with a special emphasis for bioapplications. We tested experimental abilities of Alpha 300 - the Raman microscope with AFM/SNOM accessory from WITec company. The ability of AFM to study objects of cellular dimensions was demonstrated on erythrocytes and green algae Desmodesmus quadricauda. We were able to observe growing of lysozyme protein fibrils on day scale - from dimensions of seeds (~3 nm height) up to fibrils itself (3-10 nm height and 100 nm up to micrometers length). Subsequently, we observed separate protein molecules of thyroglobulin (~6 nm) and also γ-globulin (~3 nm). It seems plausible to image objects up to 2 nm dimensions by the given device with respect to the signal/noise ratio.
Biomolecular corona of Si and Au nanoparticles and its impact on interaction with cells
Javorová, Pavlína ; Hubálek Kalbáčová, Marie (advisor) ; Fišer, Radovan (referee)
Biological response to presence of gold and silica nanoparticles is extensively researched area of science. However there is only limited knowledge and understanding of the effects of small and ultrasmall nanoparticles. Regarding the unique physical and chemical properties that originate from the small size have these nanoparticles ability to interact very specifically on molecular level with organisms. Once the particle enters the complex physiological environment of the body molecules (predominantly of protein character) adsorb on the surface and form a polymeric case called biomolecular corona. There is a presumption that the first contact of the nanoparticle with the cell is mediated through the molecules of this corona and are important in subsequent steps of interactions of nanoparticle-biocorona complex. Therefore the genesis and structure of biocorona is as essential as the structre of the nanoparticle itself. Nanoparticles enter and are internalized within the cell and cellular compartments through the same mechanisms like naturally occurring molecules and substances. There are slightly different patterns of behavior of small and ultrasmall nanoparticles that are not fully researched and understood. Response of mamallian cells to the presence of the ultrasmall nanoparticles is very...
Mechanisms of the cell migration in the early embryonic development of vertebrates
Kováčiková, Petra ; Krylov, Vladimír (advisor) ; Černý, Robert (referee)
Cell migration, usually seen as a relatively well understood phenomenon, is involved in many aspects of multicellular organisms. While given a major attention due to its part in physiological processes, such as immune response, wound-healing and regeneration, or pathologies like progression of metastatic cancers, its key role in the body plan formation is far less understood and often overlooked. During a process called gastrulation, precursors of three germ layers - superficial ectoderm, inner endoderm and medial mesoderm - are arranged according to their fate, generating a three-layered embryo, a hallmark of triblastic vertebrates. The onset of this highly coordinated step of early embryonic development is accompanied by fine-tuned cell migration, which needs to be downregulated in adults in order to maintain a homeostasis. The cells forming gastrulating embryos collectively undergo a set of behaviors termed morphogenetic movements whose features - partially comparable to ones observed on cells migrating in culture - are shared among vertebrate species, providing valuable insights into "hidden homology" and phylogenetic relationships. Research focusing on regulation and mechanisms of morphogenesis is mostly conducted using Xenopus laevis as a model organism, extrapolating results to higher...
Effect of inhaled IgY and Fab fragments on the lung inflammation
Majerová, Barbora ; Hodek, Petr (advisor) ; Koblas, Tomáš (referee)
Human respiratory system is in constant contact with heterogeneous environmental agents, which can possibly become initiators of inflammatory responses. Mechanical barriers and balance between the innate and adaptive immunity provide protection from external agents without initiation of any inflammatory response. Under certain circumstances, overreaction of the immune system might occur and leads to the production of various inflammatory cytokines and mediators such as TNF-α and GM-CSF factors or interleukins IL-1ß and IL-6. Respiratory system of the human suffering from cystic fibrosis is unable to defend against bacterial infections effectively. Chicken egg immunoglobulins (IgY) could eventually become a suitable tool for the protection from opportunistic pathogens, because they, when bound to antigen, don't activate the complement cascade. One method of determining the immunogenicity of the studied agent is the exposure of experimental animal and further measurement of inflammatory cytokine concentration. In this thesis, the potential inflammatory effect of IgY, IgY-derived Fab fragments and ovalbumin was determined after an exposure of Wistar rats by long-term inhalation. Correct implementation of inhalation experiment was confirmed via production of specific antibodies against the inhaled...
Verification of practical possibilities to strengthen the immune system in women
VRCHOTOVÁ, Nikola
The topic of this final bachelor work is immune system which comprehensively describes its function and factors that influence it. The theoretical part deals with function of the immune system, introduces its cells and organs which are split synoptically. Further on, the theoretical part describes factors with influence on the function of the immune system. These are factors which reinforce but also weaken immune system. Every factor in this work is explained with its influence on immune system and it also describes the signs of its absence or surplus in human's health. Practical part of the bachelor work deals with immune training of Hermann Geesing (2008). The immune system is applied on eight women for the time of eight months. They were noting the activities of immune training into tables during two periods May to August and September to December. The results are evaluated by two graphs. One of them shows percentage of the set activities that were fulfilled. The second one describes subjective and complex condition of the women who participated in the training. The results are rated after every period and separately on every woman. At the end, the work describes the benefit of the immune training for every woman.
Characterisation of the Physical Chemical Processes Using the Fractal and Harmonic Analysis
Haderka, Jan ; Nešpůrek, Stanislav (referee) ; Mikula,, Milan (referee) ; Zmeškal, Oldřich (advisor)
Existuje mnoho různých způsobů jak analyzovat disperzní systémy a fyzikálně chemické processy ke kterým v takových systémech dochází. Tato práce byla zaměřena na charakterizaci těchto procesů pomocí metod harmonické fraktální analýzy. Obrazová data sledovaných systémů byly analyzovány pomocí waveletové analýzy. V průběhu práce byly navrženy různé optimalizace samotné analýzy, převážně zaměřené na odstranění manuálních operací během analýzy a tyto optimalizace byly také inkorporovány do softérového vybavení pro Harmonickou Fraktální Analýzu HarFA, který je vyvíjen na Fakultě chemické, VUT Brno.

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