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Study of adhesive penetration into the wood cell wall
Janová, Petra ; Krbila, Jaromír (referee) ; Vaněrek, Jan (advisor)
This labor is based on penetration of adhesive into a wood cell walls. It focuse on adhesives basicly used for construction purposes, especially on epoxy resins. The labor contains the use of methods for precise detection adhesive in wood and methodics for choice of adhesive and wood basically used for bonding. It describes the experimentally detected dependence of contact angle on viscosity epoxy resins.
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Wood microstructure analysis onto the strength parameters
Martinek, Radomír ; Kuklík,, Pavel (referee) ; Vaněrek, Jan (advisor)
This work focuses on a closer examination of the microstructure of wood and the relationship between microscopic and mechanical properties of wood. The main point of the practical part of this study is a measurement of microfibril angle (MFA) in the S2 layer of a wood cell wall. This layer occupies more than 80 % of the total thickness of the cell wall and thus has the greatest influence on the mechanical properties of the wood cells. MFA values as well as values of bulk density show a strong dependence on the modulus of elasticity in the longitudinal direction, as well as on the values of shrinkage. The theoretical part involves methods for measuring MFA, variations of MFA, wood properties evolving from the MFA and also mechanical properties of wood cell walls measured by nanoindentation.
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Method´s analysis of submicroscopy structure of wood cell wall determination
Martinek, Radomír ; Kuklík,, Pavel (referee) ; Vaněrek, Jan (advisor)
The content of this study is focused on the influence of the structure of wood at microscopic and submicroscopic level on its mechanical properties. The wood cell wall consists of several layers, the dominant layer being layer S2, which occupies up to 80 % of the total thickness of the wood cell wall. Unique feature of this layer is that cellulose microfibrils placed in this layer are highly aligned and spirally wound around the cell axis. The inclination of these microfibrils is called microfibril angle (MFA) and is the key feature that affects mechanical properties of wood and its shrinkage. In theoretical part of this thesis methods for measuring microfibril angle are described. A method for measuring mechanical properties of the wood cell wall called nanoindentation is discussed in detail. In the practical part of this thesis, microfibril angle is measured by means of polarized light microscopy and mechanical properties of wood cell wall is determined by means of nanoindentation.
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Mycobacterium tuberculosis - structure and functions of the cell wall
Kukrálová, Simona ; Janďourek, Ondřej (advisor) ; Jílek, Petr (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Biological and Medical Sciences Study program: Bioanalytical laboratory diagnostics in healthcare Candidate: Bc. Simona Kukrálová Supervisor: PharmDr. Ondřej Janďourek, Ph.D. Title of diploma thesis: Mycobacterium tuberculosis - structure and functions of the cell wall Mycobacterium tuberculosis is an intracellular pathogen that causes a disease called tuberculosis, which, along with other selected diseases, is still one of the leading causes of mortality in the world. It is estimated that more than a million people succumb to the disease each year. The remarkable structure of the cell wall of mycobacteria has a great influence on the treatment of tuberculosis itself, together with the ever-increasing incidence of multidrug- resistant and extensively resistant strains, especially in Mycobacterium tuberculosis. The research of mycobacteria is given great attention. Efforts to find new substances with antimycobacterial effect acting on individual components of the cell wall, preferably on the cell wall as a complex, are actual and are part of national as well as international programs. Theoretical part of this diploma thesis deals with current knowledge about mycobacteria with emphasis on cell wall, epidemiology of tuberculosis...
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Preparation and characterization of chicken antibodies against pathogenic yeast Candida albicans
Vodecký, Matúš ; Hodek, Petr (advisor) ; Dračínská, Helena (referee)
The increase of infections caused by yeast pathogens is an alarming global public health problem. People with compromised immune systems, such as after infection with human immunodeficiency virus or diabetes mellitus, are most at risk. Diagnosis is often inadequate, and treatment relies on a limited selection of antifungal drugs, to which resistance is also increasing. These aspects represent a major problem, as second-choice drugs, which may have toxic side effects (e.g., nephrotoxicity in the case of amphotericin B), must then be applied to resistant pathogens. Given the severity of yeast infections, scientists are trying to find new ways of protection against these pathogens. One option is passive immunotherapy. In this bachelor thesis, antibodies from hen's eggs were chosen for this purpose, as they have the potential for wide therapeutic use. The preparation of hen's egg yolk IgY antibodies is both ethically and economically acceptable. Moreover, egg yolk antibodies show relatively high stability. Polyclonal antibodies were isolated from eggs of hens immunized with either cell wall or whole C. albicans cells in a medium simulating the vaginal environment (VSF). Antibody reactivity was tested by ELISA. The cell walls of C. albicans in VSF medium or YPD medium were used as antigen. The results...
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Chicken antibodies against the pathogenic yeast Candida albicans
Konečná, Lucia ; Heidingsfeld, Olga (advisor) ; Kubíčková, Božena (referee)
5 Abstract Candida albicans belongs to the most widespread pathogenic yeasts. As an opportunistic pathogen, it mainly colonises the mucous membranes of the host and causes infection, especially in individuals with a compromised immune system. The most common infection caused by C. albicans is vaginal mycosis, which at least 3 out of 4 women will experience during their lifetime. Antifungal drugs are used to treat this condition, but the yeasts are becoming less susceptible. For this reason, there is an effort to develop new treatment options for (not only) infections caused by C. albicans. Although vaginal mycosis is not a severe condition in most cases, it is a widespread infection that occurs repeatedly in many women, sometimes several times a year. Since vaginal mycosis reduces the quality of life in many women, we decided to focus on this disease in this paper. This project used hen antibodies, which have a number of advantages over mammalian antibodies. In oviparous animals, antibodies are not only found in the blood serum, as seen in mammals but are also secreted into their eggs. This makes the isolation of hen antibodies non-invasive and ethical. Moreover, the methods of isolating antibodies from eggs are also simpler than isolation from blood serum. Ultimately, hen antibodies are also more...
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Protease Sapp3p of the pathogenic yeast Candida parapsilosis
Sochor, Richard ; Heidingsfeld, Olga (advisor) ; Zábranská, Helena (referee)
Pathogenic yeasts of the genus Candida can cause systemic diseases which, in patients suffering from immunosuppression due to a disease such as AIDS, can cause serious pathological conditions, which can lead to the patient's death. One such yeast is the pathogenic yeast Candida parapsilosis. For the colonization and penetration of host tissues this yeast uses various virulence factors. One of these virulence factors are secreted aspartic proteases. The pathogenic yeast C. parapsilosis contains three secreted aspartic proteases Sapp1p, Sapp2p and Sapp3p, which are paralogs. The first two aspartic proteases are responsible for increasing the virulence of C. parapsilosis. They help the yeast survive in the body, by degrading important components of the host's immune system. However, Sapp3p doesn't exhibit these properties, except that it helps the yeast to adhere to abiotic surfaces to some extent. This work is focused on clarification the functions and localization of Sapp3p in the yeast C. parapsilosis. To clarify the function, precursor of Sapp3p (pro-Sapp3p) was recombinantly prepared in E. coli cells. The protein thus prepared was further tested for its autocatalytic activation and assisted activation by trypsin and Kex2p protease, under various conditions. Under the conditions tested, it was not...
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Visualization of root apoplastic pH in plants
Wernerová, Daša ; Fendrych, Matyáš (advisor) ; Paris, Nadine (referee)
Plant oriented movements, or tropisms allow the plant to actively respond to environmental stimuli to get more light, better access to nutrients and to grow roots deeper into the soil. Gravitropism drives the growth of roots along the gravity vector. Perception of gravity is triggered by the sedimentation of statoliths in columella root cap, but the exact signalling pathway behind this process is not known. Perception of gravity results in an unequal redistribution of the phytohormone auxin in the outer cell layers which leads to different rate of growth on the root's upper and lower side and bending of the root. The changes in auxin redistribution are accompanied by changes in apoplastic pH. Knowing an exact pattern of these pH changes could shed light on the mechanisms laying behind the gravitropic response pathway. While microelectrodes can be used to measure pH precisely, they are not suitable for the long-term imaging of growing roots. In the past few years, several pH sensitive dyes and genetically encoded sensors emerged. These can be used for long-term live in vivo imaging of pH changes in growing roots. In this thesis, I analysed the performance of several published pH sensitive genetically encoded sensors and available dyes in the roots of Arabidopsis thaliana. I observed that dyes varied...
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Mycobacterium tuberculosis - structure and functions of the cell wall
Kukrálová, Simona ; Janďourek, Ondřej (advisor) ; Jílek, Petr (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Biological and Medical Sciences Study program: Bioanalytical laboratory diagnostics in healthcare Candidate: Bc. Simona Kukrálová Supervisor: PharmDr. Ondřej Janďourek, Ph.D. Title of diploma thesis: Mycobacterium tuberculosis - structure and functions of the cell wall Mycobacterium tuberculosis is an intracellular pathogen that causes a disease called tuberculosis, which, along with other selected diseases, is still one of the leading causes of mortality in the world. It is estimated that more than a million people succumb to the disease each year. The remarkable structure of the cell wall of mycobacteria has a great influence on the treatment of tuberculosis itself, together with the ever-increasing incidence of multidrug- resistant and extensively resistant strains, especially in Mycobacterium tuberculosis. The research of mycobacteria is given great attention. Efforts to find new substances with antimycobacterial effect acting on individual components of the cell wall, preferably on the cell wall as a complex, are actual and are part of national as well as international programs. Theoretical part of this diploma thesis deals with current knowledge about mycobacteria with emphasis on cell wall, epidemiology of tuberculosis...
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