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Volumetric model of human vocal folds
Vampola, T. ; Horáček, Jaromír
The article describes the vollumetric 3D FE model of real human vocal folds in a defined phonation position. The model was developed from the CT images of the plaster casts obtained by a special procedure during experiments with the excised human larynges, when the phonatioon caused by the airflow was suddenly stopped without changing the position of the fixed larynx. The model is determined for studies of dynamical stresses in the vocal fold tissue during vocal folds collisions.
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Gender Selection as a Topic of Bioethics
Hendlová, Tereza ; Kolářová, Kateřina (advisor) ; Kiczková, Zuzana (referee)
My thesis focuses on the topic of gender selection (deliberate determination of the child's gender which is now possible thanks to recent developments in reproductive medicine) from the perspective of biomedical ethics. The main question is whether the practise of gender selection complies with the 4 basic principles of bioethics against which all medical action should be assessed (principle of autonomy, non-maleficence, beneficence and justice). In the thesis, I distinguish between two main types of gender selection: gender selection for medical and non-medical reasons. The main focus is put on the second type, which is more ethically disputable, as it is not as directly related to the child's health and well-being as the first type. Gender selection for non-medical reasons is practiced in the context of multiple interactions of social, political, economic and other factors that all inform parental choices. One of the very influential factors is the medical discourse. For the purpose of complex contextualisation of gender selection for non-medical reasons, the concept of procreative liberty (introduced by J.A. Robertson) and feminist critiques of reproductive choices are presented. My main argument is that gender selection for non-medical reasons should not be legal and available as it has a high potential...
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The Role of Gut Microbiota and Lipopolysachaide Content of the Diet in the Development, Maturation and Function of the Immune System
Hrnčíř, Tomáš ; Tlaskalová - Hogenová, Helena (advisor) ; Prokešová, Ludmila (referee) ; Macela, Aleš (referee)
Mammals are essentially born germ-free but the epithelial surfaces are promptly colonized by astounding numbers of bacteria soon after birth. The most extensive microbial community is harboured by the distal intestine. The gut microbiota outnumbers ~10 times the total number of our somatic and germ cells. The hostmicrobiota relationship has evolved to become mutually beneficial. Studies in germfree mice have shown that gut microbiota is essential for the proper development of the immune system. The pivotal role of the innate immune system in the complex and dynamic host-microbiota interactions has become increasingly evident. The principal aims of the present study were: firstly, to determine whether LPS-rich sterile diet can promote maturation of the immune system in germ-free mice, secondly, to elucidate whether gut microbiota and LPS-rich sterile diet influence the LPS susceptibility, and finally, to investigate a role of the adaptive immunity in endotoxin shock. Our data clearly show that both live gut microbiota and LPS-rich sterile diet increase susceptibility to endotoxin shock. Further, we demonstrate that immunodeficient SCID mice, which lack mature B and T cells, are more sensitive to endotoxin shock than immunocompetent Balb/c mice. In addition, we show that not only live gut microbiota but also...
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The endocrine function of adipose tissue and its importance for initiation and development of insulin resistance and diabetes
Haluzík, Michal ; Schreiber, Vratislav (advisor) ; Marešová, Dana (referee) ; Šeda, Ondřej (referee)
Endocrine production of adipose tissue is a very complex process affected by numerous endogenous and exogenous stimuli. Peroxisome proliferator-activated receptors-alpha (PPAR-) are important modulators of metabolic processes which can also affect endocrine function of adipose tissue. Recently, numerous novel factors produced by adipose tissue with important metabolic effects were identified. Some of them can directly bind PPAR receptors. One of the examples of these factors is fatty acid binding protein 4 (FABP4) which can directly bind PPAR receptors and indirectly modify its activation by changing availability of endogenous PPAR ligands -free fatty acids. We hypothesized that the mechanism of action of PPAR receptors to metabolic processes may partially lie in their complex interaction with adipose tissue-derived hormones. The unraveling of these interactions may have important consequences in finding approaches to treat patients with type 2 diabetes mellitus. (...) In summary, our data show an important role for the interplay of PPAR activation and endocrine function of adipose tissue in metabolic regulations which may have important clinical consequences.
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Plasma spraying from liquids: plasma liquid interaction and coating build up
Tesař, Tomáš ; Mušálek, Radek ; Medřický, Jan ; Lukáč, František
Plasma spraying from liquid feedstocks is a rapidly developing field of thermal spraying since the coatings prepared from liquids exhibit some unique features, such as high hardness, thermal shock resistance or low thermal and electric conductivity. The key factor influencing the final coating character and properties is the input material which may be in the form of a suspension or a solution. Parameters of the selected suspension (solids concentration, viscosity, surface tension, chemical composition, etc.) or solution (concentration, etc.) determine its interaction with the plasma jet which strongly influences the coating buildup. This proceeding introduces the problematics of the interaction between the liquid feedstock material with the plasma jet and presents the way of evaluation of the coating buildup.
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Freezing technology of bull sperm in relation to its survivability and fertilization ability
Doležalová, Martina ; Stádník, Luděk (advisor) ; Jiří, Jiří (referee)
The aim of optimalization the insemination doses production is to provide the highest fertilization ability of spermatozoa during the demanding proces of processing fresh semen and its subsequent cryopreservation. Temperature changes causes spermatozoa damage during the cooling and freezing. Spermatozoa is exposed to cold shock and many others limiting factors, which leads to cell death and therefore to decline of fertilization ability of thawed insemination doses. For increasing spermatozoa resistance, exactly the plasma membrane resistance against cold shock was fraction of egg yolk LDL cholesterol (low density lipoprotein) at various concentrations into the comercially produced diluents added. It is believed that LDL acts possitively to plasma membrane and helps to maintain the fertilization ability of spermatozoa after thawing. Following step in the proces of insemination doses production is slow cooling of diluted semen and equilibration, when the straws are store at cooling box for 30 minutes to 240 hours. This period is necessary to penetrate of certain diluent components into the spermatazoa also maintain the balance between their intracellular and extracellular concentration. Also important is subsequent freezing temperature gradient of insemination doses. The most suitable freezing method is based on computer controlled temperature decline in freezing chamber which allows the precise control of ice crystals formation that could tear and kill the cell.
During 2012 to 2016 was repeatedly collected semen from the group of breeding bulls (n = 27, Holstein and Czech Fleckvieh breed) at AI centre. Semen which fulfill the standard entrance conditions in first step was evenly into several parts divided. For dilution the three types of comercially diluents AndroMed, Bioxcell and Triladyl with and without LDL addition were used. Into the diluents AndroMed and Bioxcell the concentration of LDL 4 %, 6 % and 8% into the dilent Triladyl 6 %, 8 % and 10 % was added. Diluted semen was filled into the glass capillares with volume 0,1 ml and temperature +4 °C. Subsequently the sample was placed to cold bath (0°C) for 10 minutes. Then the volume of capillare with physiological solution (37 °C) was mixed and for next 120 minutes was incubate. The effect of cold shock to proportion of live spermatozoa was evaluated by using Eosin and Nigrosine staining technique during heat test of spermatozoa survivability after spermatozoa heating and after 120 minutes of incubation.
The more suitable semen diluents which provide the higher spermatozoa resistance against cold shock were AndroMed and Bioxcell. Together the possitive effect of LDL addition into the diluents to lower decrease of proportion of live spermatozoa during heat test was found (P<0.05). The most suitable LDL concentration which had a favorable influence at spermatozoa resistance against cold shock was 6 % in diluent Bioxcell. Values of the proportion of live sperm were higher at the beginning of the heat test (+1.31% to + 3.2%) and after 120 minute incubation (+5.82% to +8.41%) compared to other diluents with and without addition of LDL.
In the next step the process of equilibration was optimized, is an important part of insemination doses production. The effect of the length of equilibration for subsequent fertilization ability of spermatozoa was evaluated using spermatozoa motility based of CASA and proportion of live spermatozoa after thawing and during heat survival test lasting 120 minutes (37 ° C). Suitable semen was diluted by comercially used diluent AndroMed based on soya lecithin, filled into the straws (0.25 ml), cooled and equilibrated in cooling box for 30, 120 and 240 minutes and freezed in programmable freezing box applying four types of freezing curves differing in temperature rate decline. There was used standard and by producer recommended 3. phase freezing curve, then 2. phase freezing curve, and 3. phase freezing curve with slower as well as rapid decline of temperature rate in freezing chamber, compared with standard freezing curve. The highest spermatozoa motility was found using 240 minutes of equilibration by +2.72% and +4.58% compared to other lengths of equilibration (P <0.05 to 0.01). The highest proportion of live spermatozoa was found using 120 minutes of equilibration (+6.87 % and +8.68 %). The highest average spermatozoa motility during heat test after thawing was achieved by using 2. phase freezing curve (from +2.97% to +10.37%, P <0.05), also in the proportion of live spermatozoa (from + 4.37% to +8.82%, P <0.01). When evaluating interaction between the length of equilibration and freezing curve (standard 3. phase and 2 . phase freezing curve), the highest average spermatozoa motility and proportion of live spermatozoa using 240 minutes of equilibration by both freezing curves was reached, there was no statistically significant differences. As well as, in all evaluated parts of this study the individual differences between ejaculate of bulls and within semen from one bull (P <0.05) as secondary effect were found.
To maintain good fertilization ability of semen during cryopreservation is necessary to increase the spermatozoa resistance against cold shock using addition of correct concentration of LDL into the commercially used diluents AndroMed and Bioxcell. Subsequently the fertilization ability of insemination dose is influenced by cooling, the length of equilibration and freezing. The length of equilibration 120 minutes and more as well as gentle way of freezing according to freezing curve, which ensures a gradual decrease of temperature in freezing chamber provided the higher average spermatozoa motility and proportion of live spermatozoa.
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