44 research outputs found

    Steam boiler for fytomass

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    Tato diplomová práce se zabývá návrhem kotle na spalování výpalků lihovarů. Ze zadaných parametrů jsou vypočteny stechiometrické výpočty a entalpie spalin. Dále byl proveden tepelný výpočet, návrh rozměrů spalovací komory a dimenzování teplosměnných ploch. Kotel má výparník s přirozenou cirkulací a roštové ohniště.This diploma thesis deals with a design of a boiler for stillage combustion. Stoichiometric calculations and enthalpies of combustion gases have been calculated from the specified parameters. In addition, heat calculation, design of the combustion chamber dimensions and dimensioning of heat surfaces were accomplished. The boiler has an evaporator with natural circulation and a fire grate.

    Alternativní zemědělství - informační bulletin č.7

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    Témata informačního bulletinu č.7 jsou: Vyhodnocení výnosů zemědělských plodin v roce 1991 u organicky hospodařících zemědělců svazu PRO-BIO. Nutnost moření osiva z hlediska alternativního zemědělství. Využití přirozených surovin v alternativním zemědělství. Mechanická regulace plevelů. Možnosti realizace alternativního zemědělství z hlediska ochrany rostlin. Regulace hraboše polního bez chemie. Úvod k připravované knize "Ekologická východiska zemědělství". Stáj s hlubokou podestýlkou pro dojnice z hlediska etologie a ekonomiky. Zelené hnojení. Organické vinohradnictví

    AFM Monitoring the Influence of Selected Cryoprotectants on Regeneration of Cryopreserved Cells Mechanical Properties

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    Cryopreservation of cells (mouse embryonic fibroblasts) is a fundamental task for wide range of applications. In practice, cells are protected against damage during freezing by applications of specific cryoprotectants and freezing/melting protocols. In this study by using AFM and fluorescence microscopy we showed how selected cryoprotectants (dimethyl sulfoxide and polyethylene glycol) affected the cryopreserved cells mechanical properties (stiffness) and how these parameters are correlated with cytoskeleton damage and reconstruction. We showed how cryopreserved (frozen and thawed) cells' stiffness change according to type of applied cryoprotectant and its functionality in extracellular or intracellular space. We showed that AFM can be used as technique for investigation of cryopreserved cells surfaces state and development ex vivo. Our results offer a new perspective on the monitoring and characterization of frozen cells recovery by measuring changes in elastic properties by nanoindentation technique. This may lead to a new and detailed way of investigating the post-thaw development of cryopreserved cells which allows to distinguish between different cell parts

    Cellular mechanosensing by means of atomic force microscopy

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    Mechanobiological sensing brings together biology, physics, medicine and engineering, thus helps to characterize how the protein molecules, cells and tissues respond to mechanical cues contribute to differentiation, development, structural and disease processes. The mechanobiology contributes to recognition of the sensing, transduction and application of mechanical signals by the biological systems. Atomic force microscopy (AFM) has grew up from the solid material characterization method to the a important device allowing the simultaneous topographical and mechanical characterization of living biological systems. In this work such a potential of the AFM method will be described on selected examples. It was shown that cell stiffness determined by AFM can be used as a marker for cancer progression and metastatic potential. Different cancer types feature distinct cell stiffness and a connection between attenuated cell stiffness and increased invasion capacity was also observed. The force microscope can serve as mechanotransducing actuator of the cardiac cells contractility. Combination with the other methods, such as microelectrode array, leads to a comprehensive description of the contractile phenomenon. Pathophysiological electro-mechanical coupling needs to be characterized in a detail, if the alterations often resulting in mechanical heart failure would be understand and treated. \We would like to demonstrate AFM together with other biophysical methods brings a promising approach that helps understand the correlation between the cell structure, cell mechanics, and function

    Role of oxygen exposure on the differentiation of human induced pluripotent stem cells in 2D and 3D cardiac organoids

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    Introduction Human induced pluripotent stem cells (hiPSC) have the ability to differentiate theoritically into any cell type. The development of organoid systems exhibiting the essential features of human organ such as liver and heart is of high interest. Optimizing the culture conditions to obtain the highest cardiac organoids efficacy is crucial. In fact, cardiac differentiation protocols have been established by essentially focusing on specific growth factors on hiPSC differentiation efficiency. However, the optimal environmental factors such as the optimal oxygen exposure to obtain cardiac myocytes in network are still unclear. The mesoderm germ layer differentiation is known to be enhanced by low oxygen exposure. Yet, the effect of low oxygen exposure on the molecular and functional maturity of the hiPSC-derived cardiomyocytes remains unexplored. Aims We aimed here at comparing the molecular and functional consequences of low (5% O2 or LOE) and high oxygen exposure (21% O2 or HOE) on cardiac differentiation of hiPSCs in 2D monolayer and 3D organoids protocols. Methods hiPSC-CMs were differentiated through both the 2D (monolayer) and 3D (embryoid body) protocols using several lines. Cardiac marker expression and cell morphology were assessed using qRT-PCR and immunofluorescence. The mitochondrial localization and metabolic properties were evaluated by high-resolution respirometry and mitochondrial staining. The intracellular Ca2+ handling and contractile properties were also monitored using confocal fluorescent microscopy and atomic force microscopy. Results Our results indicated that the 2D cardiac monolayer can only be differentiated in HOE. The 3D cardiac organoids containing hiPSC-CMs in LOE exhibited higher cardiac markers expression such as troponin T (TnTc), RyR2, Serca2a, alpha and beta heavy myosin chains. Moreover, we found enhanced contractile force, hypertrophy and steadier SR Ca2+ release reflected by a more regular spontaneous Ca2+ transients associated with a higher maximal amplitude and lower spontaneous Ca2+ events revealing a better SR Ca2+ handling in LOE. Similar beat rate, preserved distribution of mitochondria and similar oxygen consumption by the mitochondrial respiratory chain complexes were also observed. Conclusions Our results brought evidences that LOE is moderately beneficial for the 3D cardiac organoids with hPSC-CMs exhibiting further maturity. In contrast, the 2D cardiac monolayers strictly require HOE.Introduction Human induced pluripotent stem cells (hiPSC) have the ability to differentiate theoritically into any cell type. The development of organoid systems exhibiting the essential features of human organ such as liver and heart is of high interest. Optimizing the culture conditions to obtain the highest cardiac organoids efficacy is crucial. In fact, cardiac differentiation protocols have been established by essentially focusing on specific growth factors on hiPSC differentiation efficiency. However, the optimal environmental factors such as the optimal oxygen exposure to obtain cardiac myocytes in network are still unclear. The mesoderm germ layer differentiation is known to be enhanced by low oxygen exposure. Yet, the effect of low oxygen exposure on the molecular and functional maturity of the hiPSC-derived cardiomyocytes remains unexplored. Aims We aimed here at comparing the molecular and functional consequences of low (5% O2 or LOE) and high oxygen exposure (21% O2 or HOE) on cardiac differentiation of hiPSCs in 2D monolayer and 3D organoids protocols. Methods hiPSC-CMs were differentiated through both the 2D (monolayer) and 3D (embryoid body) protocols using several lines. Cardiac marker expression and cell morphology were assessed using qRT-PCR and immunofluorescence. The mitochondrial localization and metabolic properties were evaluated by high-resolution respirometry and mitochondrial staining. The intracellular Ca2+ handling and contractile properties were also monitored using confocal fluorescent microscopy and atomic force microscopy. Results Our results indicated that the 2D cardiac monolayer can only be differentiated in HOE. The 3D cardiac organoids containing hiPSC-CMs in LOE exhibited higher cardiac markers expression such as troponin T (TnTc), RyR2, Serca2a, alpha and beta heavy myosin chains. Moreover, we found enhanced contractile force, hypertrophy and steadier SR Ca2+ release reflected by a more regular spontaneous Ca2+ transients associated with a higher maximal amplitude and lower spontaneous Ca2+ events revealing a better SR Ca2+ handling in LOE. Similar beat rate, preserved distribution of mitochondria and similar oxygen consumption by the mitochondrial respiratory chain complexes were also observed. Conclusions Our results brought evidences that LOE is moderately beneficial for the 3D cardiac organoids with hPSC-CMs exhibiting further maturity. In contrast, the 2D cardiac monolayers strictly require HOE

    Influence of Structure of Ionic Liquids on the Properties of their Mixtures with Water

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    This contribution reports on a part of the results of a project focused on imidazolium-based ILs with a bis{(trifluoromethyl)sulfonyl}imide anion. The choice of the studied ILs is motivated by a study of the influence of the cation structure on the physico-chemical properties of pure ionic liquids and their mixtures with molecular solvents. For this purpose, four isomeric ILs, namely 1-alkyl-3-butylimidazolium bis{(trifluoromethyl) sulfonyl}imides (abbreviated [C4xC5im][Tf2N], alkyl = pentyl, isopentyl, 3-pentyl, or cyclopentyl) were selected. In a previous work, fundamental physico-chemical properties such as density, isobaric heat capacity, viscosity, electrical conductivity were measured.2 In this part of the study, the properties of the studied range of ILs in systems with water were investigated

    Steam boiler for fytomass

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    This diploma thesis deals with a design of a boiler for stillage combustion. Stoichiometric calculations and enthalpies of combustion gases have been calculated from the specified parameters. In addition, heat calculation, design of the combustion chamber dimensions and dimensioning of heat surfaces were accomplished. The boiler has an evaporator with natural circulation and a fire grate

    Study of Impurities and their Effect on the Physico-Chemical Properties of Ionic Liquids.

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    The primary aim of the present study is to characterize thermophysically three novel ionic liquids 1-(2-(2ethoxyethoxy)ethyl)-3-alkylimidazolium with the bistriflate anion, where the alkyl stands for pentyl, isopentyl or neopentyl. For this purpose thermodynamic and transport properties such as density, heat capacity, electrical conductivity, and viscosity are studied

    An aristocratic art patronage in the second half of the 19th century (Aristocracy in the Association of fine arts and the Society of the patriotic friends of arts)

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    The dissertation inquires into the participation of the historic aristocracy in the agency of the Society of the patriotic friends of arts and the Association of fine arts. On the basis of an analysis of the annual reports of both of the institutions a survey of selected aristocratic contributors and donators of works of art will be made. In addition to this, the dissertation focuses on several of the more or less noted aristocratic members of the named institutions. In this respect a form of their interest in collecting of artworks and in art patronage, shortly {--} in their virtu, will also be partly dealt with. As an introduction to the subject the survey is preceded by a text dealing with even earlier activities concerning art patronage and art collections that occured in the region of the Czech kingdom and also the Margraviate of Moravia
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