Comparison of laser welds with using direct and scanner welding head

Práce předkládá porovnání přímého laserového a skenerového svařování. Nejprve je pomocí literární studie vysvětlena technologie laserového svařování a poté následuje praktické srovnání těchto metod. Experimenty byly provedeny na austenitické korozivzdorné oceli X5CrNi18-10 a na konstrukční oceli S235JR. U metod byly porovnány svařovací časy, geometrie a tvrdosti svaru, mechanické vlastnosti a také ekonomika použití v praxi. Ze srovnání vyplývá, že skenerové svařování je kvalitativně rovnocenné s konvenčním laserovým svařováním a navíc je ekonomicky výhodnější.The master thesis presents a comparison of direct laser and scanner welding. At first, using literary studies explained the technology of laser welding, followed by a practical comparison of these methods. The experiments were performed on austenitic stainless steel X5CrNi18-10 and S235JR structural steels. These methods were compared in welding times, geometry and weld hardness, mechanical properties and economy of use in industry. The comparison shows that the scanner welding is qualitatively equivalent to the conventional laser welding and is also economical.

Analysis of value of functional neuroimaging methods in diagnostics of focal intractable epilepsy

Epilepsy is one of the most common neurological disorders with prevalence 0,5 to 1 %. Considerable number of patients (particularly children) suffers from intractable focal epilepsy caused by focal cortical dysplasia (FCD) - a localized malformation of cortical development. The only treatment option in these patients remains resective epilepsy surgery. Its goal is to remove the epileptogenic zone (EZ) defined as the area of the cerebral cortex that is indispensable for the generation of epileptic seizures. There is currently no exclusive diagnostic test for localizing EZ localization; the localization hypothesis is based on combination of more diagnostic methods. Neuroimaging methods (especially magnetic resonance imaging - MRI) are crucial for localizing EZ; however, functional neuroimaging methods analyzing different functional aspects of the brain tissue can be equally important. The goal of this PhD study is to analyze value of functional neuroimaging methods (especially SPECT and SISCOM respectively and FDG-PET) for the EZ localization in patients with focal intractable epilepsy. In the first presented study we analyzed value of ictal SPECT examination for the EZ localization in a large cohort of pediatric patients with FCD operated on in Miami Children's Hospital, Florida. The study proved that..

Influence of type of base sand on strength of geopolymer sand mixture

Cílem této práce je zjistit vliv typu ostřiva na pevnost geopolymerních formovacích směsí. Byly použity čtyři křemenná ostřiva a dva typy pojiv. Zvolený problém jsem řešil pomocí zkoušky pevnosti v ohybu. Nejdříve jsem připravil formovací směs a po jejím ztvrdnutí jsem měřil její pevnost v ohybu. A to vždy ve třech časech 60, 120 a 1440 minut. Nejvyšší pevnosti se podařilo dosáhnout u ostřiva ŠH-34 za použití pojiva Geopol 618. Hodnota pevnosti v ohybu byla 0,881MPa. Výsledky těchto měření by mohly pomoci slévárnám při zavádění technologie geopolymerů, a to především při hledání vhodného ostřiva.The goal of this research is to find out the effect of different types of opening material on bending strength geopolymer’s moulding mixture. Four different silical opening material were used along with two types of binder. To solve the selected problem I have used the test of bending strength. At first I have prepared the moulding mixture and after its induration, I have tested the bending strength. The times were always the same 60, 120 and 1440 minutes. The highest level of bending strength was achieved at opening material SH-34 when using binder Geopol 618. The value of bending strength level was 0,881MPa. The results of this research could help the foundries during implementing technology of geopolymer moulding mixture, which would help particulary when looking for a proper opening material.

A boy with developmental delay and mosaic supernumerary inv dup(5)(p15.33p15.1) leading to distal 5p tetrasomy – case report and review of the literature

Abstract Background With only 11 patients reported, 5p tetrasomy belongs to rare postnatal findings. Most cases are due to small supernumerary marker chromosomes (sSMCs) or isochromosomes. The patients share common but unspecific symptoms such as developmental delay, seizures, ventriculomegaly, hypotonia, and fifth finger clinodactyly. Simple interstitial duplications leading to trisomies of parts of 5p are much more frequent and better described. Duplications encompassing 5p13.2 cause a defined syndrome with macrocephaly, distinct facial phenotype, heart defects, talipes equinovarus, feeding difficulties, respiratory distress and anomalies of the central nervous system, developmental delay and hypotonia. Case presentation We present a boy with dysmorphic features, developmental delay, intellectual disability and congenital anomalies, and a mosaic sSMC inv dup(5)(p15.33p15.1). He is the fourth and the oldest reported patient with distal 5p tetrasomy. His level of mosaicism was significantly different in lymphocytes (13.2%) and buccal cells (64.7%). The amplification in our patient is smaller than that in the three previously published patients but the only phenotype difference is the absence of seizures in our patient. Conclusions Our observations indicate that for the assessment of prognosis, especially with respect to intellectual functioning, the level of mosaicism could be more important than the extent of amplification and the number of extra copies. Evaluation of the phenotypical effect of rare chromosomal aberrations is challenging and each additional case is valuable for refinement of the genotype-phenotype correlation. Moreover, our patient demonstrates that if the phenotype is severe and if the level of sSMC mosaicism is low in lymphocytes, other tissues should be tested

Cognitive performance in distinct groups of children undergoing epilepsy surgery—a single-centre experience

Background We aimed first to describe trends in cognitive performance over time in a large patient cohort (n = 203) from a single tertiary centre for paediatric epilepsy surgery over the period of 16 years divided in two (developing—pre-2011 vs. established—post-2011). Secondly, we tried to identify subgroups of epilepsy surgery candidates with distinctive epilepsy-related characteristics that associate with their pre- and post-surgical cognitive performance. Thirdly, we analysed variables affecting pre-surgical and post-surgical IQ/DQ and their change (post- vs. pre-surgical). Methods We analysed IQ/DQ data obtained using standardized neuropsychological tests before epilepsy surgery and one year post-surgically, along with details of patient’s epilepsy, epilepsy surgery and outcomes in terms of freedom from seizures. Using regression analysis, we described the trend in post-operative IQ/DQ. Cognitive outcomes and the associated epilepsy- and epilepsy surgery-related variables were compared between periods before and after 2011. Using multivariate analysis we analysed the effect of individual variables on pre- and post-operative IQ/DQ and its change. Results Epilepsy surgery tends to improve post-surgical IQ/DQ, most significantly in patients with lower pre-surgical IQ/DQ, and post-surgical IQ/DQ strongly correlates with pre-surgical IQ/DQ (Rho = 0.888, p < 0.001). We found no significant difference in pre-, post-surgical IQ/DQ and IQ/DQ change between the periods of pre-2011 and post-2011 (p = 0.7, p = 0.469, p = 0.796, respectively). Patients with temporal or extratemporal epilepsy differed in their pre-surgical IQ/DQ (p = 0.001) and in IQ/DQ change (p = 0.002) from those with hemispheric epilepsy, with no significant difference in post-surgical IQ/DQ (p = 0.888). Groups of patients with different underlying histopathology showed significantly different pre- and post-surgical IQ/DQ (p < 0.001 and p < 0.001 respectively) but not IQ/DQ change (p = 0.345).Variables associated with severe epilepsy showed effect on cognitive performance in multivariate model. Discussion Post-surgical IQ/DQ strongly correlates with pre-surgical IQ/DQ and greatest IQ/DQ gain occurs in patients with lower pre-surgical IQ/DQ scores. Cognitive performance was not affected by changes in paediatric epilepsy surgery practice. Pre- and post-operative cognitive performances, as well as patients’ potential for cognitive recovery, are highly dependent on the underlying aetiology and epileptic syndrome

Clinical features and blood iron metabolism markers in children with beta-propeller protein associated neurodegeneration

Background: Neurodegeneration with brain iron accumulation constitutes a group of rare progressive movement disorders sharing intellectual disability and neuroimaging findings as common denominators. Beta-propeller protein-associated neurodegeneration (BPAN) represents approximately 7% of the cases, and its first signs are typically epilepsy and developmental delay. We aimed to describe in detail the phenotype of BPAN with a special focus on iron metabolism. Material and methods: We present a cohort of paediatric patients with pathogenic variants of WD-Repeat Domain 45 gene (WDR45). The diagnosis was established by targeted panel sequencing of genes associated with epileptic encephalopathies (n = 9) or by Sanger sequencing of WDR45 (n = 1). Data on clinical characteristics, molecular-genetic findings and other performed investigations were gathered from all participating centres. Markers of iron metabolism were analysed in 6 patients. Results: Ten children (3 males, 7 females, median age 8.4 years) from five centres (Prague, Berlin, Vogtareuth, Tubingen and Cologne) were enrolled in the study. All patients manifested first symptoms (e.g. epilepsy, developmental delay) between 2 and 31 months (median 16 months). Seven patients were seizure-free (6 on antiepileptic medication, one drug-free) at the time of data collection. Neurological findings were non-specific with deep tendon hyperreflexia (n = 4) and orofacial dystonia (n = 3) being the most common. Soluble transferrin receptor/log ferritin ratio was elevated in 5/6 examined subjects; other parameters of iron metabolism were normal. Conclusion: Severity of epilepsy often gradually decreases in BPAN patients. Elevation of soluble transferrin receptor/log ferritin ratio could be another biochemical marker of the disease and should be explored by further studies. (c) 2020 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved

Additional file 1: of A boy with developmental delay and mosaic supernumerary inv dup(5)(p15.33p15.1) leading to distal 5p tetrasomy – case report and review of the literature

Table S1. Detailed description of encompassed genes. (XLS 328 kb

Additional file 2: of A boy with developmental delay and mosaic supernumerary inv dup(5)(p15.33p15.1) leading to distal 5p tetrasomy – case report and review of the literature

Table S2. Comparison of clinical features of patients with 5p tetrasomies. (XLS 41 kb