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Productive Machining of Titanium Alloys
Slabý, Ondřej ; Sliwková, Petra (referee) ; Píška, Miroslav (advisor)
This diploma thesis is focused on a productive machining of titanium alloys. At the beginning it deals about titanium and its alloys. It describes chip generation mechanism, tool blunting and surface quality. Further it contains modern strategies of efficient titanium alloys machining. Then it analyzes contemporary manufacturing technology of hinge made of titanium alloy Ti-6Al-4V in Frentech Aerospace s.r.o. company, and at the end finds possibility of savings by inovation of roughing process.
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The use of social networks of youth in a leisure time
SLABÝ, Ondřej
This bachelor thesis deals with the issue of using social networks in the leisure time of young people. The main goal of the work is to find out how young people use social networks in their free time. Other sub-objectives were to find out how young people spend their free time, how they perceive space on social networks and whether the use of social networks can have a negative effect on the adolescent. In the theoretical part we will try to define the terms with which we will continue to work in the practical part. In the first chapter we will explain the concept of leisure time and its appreciation, and we will also define the concept of youth. In the next chapter we will deal with social networks. We will address the specifics of the virtual environment, define what a virtual identity is and also focus on the mental health of young people in the context of using social networks. In the practical part we will clarify the goals of the research and the methods we will proceed in investigating the research problem. We analyze the research results and evaluate the findings.
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The expression of miRNA in HPV-associated and HPV-independent head and neck tumors
Vojtěchová, Zuzana ; Tachezy, Ruth (advisor) ; Hejnar, Jiří (referee) ; Slabý, Ondřej (referee)
Head and neck cancers represent a group of tumors with two different etiologies. The first type is associated with the viral HPV infection, the second one is virus-independent and it is associated with smoking and alcohol consumption as two main risk factors. Numerous studies show that HPV-positive tumors are more frequent in younger patients, as well as that the prognosis and overall survival of these patients is remarkably better. Therefore, the modification of the treatment is considered. For this, however, specific, sensitive and clinically relevant biomarkers for accurate identification of tumor etiology is needed. Suitable candidates for such biomarkers are miRNAs, small non-coding regulatory molecules stable in archived samples, that have been shown as differentially expressed in human cancers and the expression pattern seems specific for tumors of different origin. The submitted thesis focuses on miRNA profiling in HPV-positive and HPV-negative tonsillar tumors and cervical carcinomas with the aim to find out the differences between regulation of important carcinogenetic pathways of tumors of viral and non-viral etiology. Our data have shown very large heterogeneity of the miRNA expression profiles of these tumors. Despite the well characterized and uniform samples collection, we have found...
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Modulation of sporadic colorectal cancer risk by polymorphisms and haplotypes of mismatch repair genes
Tulupova, Elena ; Šrám, Radim (advisor) ; Rubeš, Jiří (referee) ; Slabý, Ondřej (referee)
Sporadic colorectal cancer (CRC) is a common disease with complex aetiology and diverse molecular phenotypes. Failure of DNA repair systems is one of the leading determinants of cancer onset and development. The efficiency of these systems and susceptibility to cancer can be affected by genotype variations, including common single nucleotide polymorphisms (SNPs). In this work, an association between SNPs and haplotypes of DNA mismatch repair (MMR) genes, SNPs and their combinations in other DNA repair genes, and a risk of sporadic CRC was investigated in a hospital-based case-control study. As result of our study, certain MMR SNPs and haplotypes altered CRC risk, as demonstrated for the first time in the Czech population. Individual SNPs in DNA repair genes seem to have a limited effect on CRC risk, with possible modification by age or smoking. Several of the associations observed were site-specific, confirming the molecular heterogeneity of CRC. DNA repair capacity varies significantly between individuals, between different tissues of the same organism, and also between malignant and normal cells. To assess the background level of this variability, the association between SNPs in DNA repair genes and the individual DNA repair capacity in healthy individuals was investigated. Several polymorphisms...
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Relation of tumor genotype and phenotype to diagnosis, prognosis and prediction of colorectal cancer
Pitule, Pavel ; Králíčková, Milena (advisor) ; Vožeh, František (referee) ; Slabý, Ondřej (referee)
Colorectal cancer is one of the most common type of malignity. Despite of the existence of numerous studies focused on this carcinoma, there are still many unknown features regarding its diagnosis, treatment or prognosis. In the thesis we focused on the identification of novel prognostics markers that could be useful for the stratification of patients based on the disease outcomes. In the first study we immunohistochemically assessed expression of two proteins associated with cancer stem cells in the samples of primary colorectal cancer and matched liver metastasis. Goal of the study was to evaluate relation among expression of CD44 and CD133 and overall survival and disease free interval in our set of patients. We observed that increased ratio of CD133 positive compared to CD133 negative tumor glands resulted in longer disease free interval, finding which is opposite to the general view on the CD133 role in the cancer development. Our hypothesis is that we analyzed confined group of patients and followed a bit different goal, where we measured ratio between positive and negative glands in the view-field and not the intensity of staining as the previous studies did. Our second study was focused on the transcriptional analysis of the selected set of twelve genes using frozen samples from colorectal...
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The expression of miRNA in HPV-associated and HPV-independent head and neck tumors
Vojtěchová, Zuzana ; Tachezy, Ruth (advisor) ; Hejnar, Jiří (referee) ; Slabý, Ondřej (referee)
Head and neck cancers represent a group of tumors with two different etiologies. The first type is associated with the viral HPV infection, the second one is virus-independent and it is associated with smoking and alcohol consumption as two main risk factors. Numerous studies show that HPV-positive tumors are more frequent in younger patients, as well as that the prognosis and overall survival of these patients is remarkably better. Therefore, the modification of the treatment is considered. For this, however, specific, sensitive and clinically relevant biomarkers for accurate identification of tumor etiology is needed. Suitable candidates for such biomarkers are miRNAs, small non-coding regulatory molecules stable in archived samples, that have been shown as differentially expressed in human cancers and the expression pattern seems specific for tumors of different origin. The submitted thesis focuses on miRNA profiling in HPV-positive and HPV-negative tonsillar tumors and cervical carcinomas with the aim to find out the differences between regulation of important carcinogenetic pathways of tumors of viral and non-viral etiology. Our data have shown very large heterogeneity of the miRNA expression profiles of these tumors. Despite the well characterized and uniform samples collection, we have found...
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Expression and prognostic value of microRNAs in patients with early breast cancer.
Sochor, Marek ; Tesařová, Petra (advisor) ; Slabý, Ondřej (referee) ; Hajdúch, Marián (referee)
Breast cancer is the most frequent cancer in women and is prognostically very heterogeneous. Early breast cancer has an excellent overall prognosis with long-term survival above 90%. In this group we can also find patients with highly unfavourable progress with a risk of future disease relapse. Due to effective anticancer treatment is a main task of precise clinical decision to determine risk of an individual patient in the term of cancer relapse. We can use clinical (tumor diameter, lymph nodes) and pathological markers (grade, ER, PgR, HER2, and Ki-67), all of them have low individual sensitivity and specificity. Molecular tests based on multigene DNA or RNA assays have higher sensitivity and specificity but their interrelated concordance is low. One of the main scientific task is to find almost specific and sensitive prognostic biomarkers. microRNAs are small, highly stable, non-coding RNAs, which regulate tens of mRNAs and proteins inside cells. In cancerogenesis, they could act as oncogenes or tumor supressors as well and affect main steps of initiation and progression of cancer. One of the scientific directions is to determine their prognostic significance. Many experimental and clinical studies defining prognostic significance of miRs in early breast cancer was published but their data were...
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