Helium permeation through mixed matrix membranes based on polyimides and silicalite-1

Mixed matrix membranes based on modified polyimides and silicalite-1 were prepared and studied. The novel preparation approach consists in improvement of the interfacial adhesion by employment of the coupling agent 3-aminopropyltriethoxysilane in such a way which leads to forming of chemical bonds between polyimide and silicalite-1. Firstly polyimide chains were endcapped by this agent which subsequently enabled their reaction with groups naturally present on silicalite-1 surface. Membranes with silicalite-1 content up to 60 wt. % were prepared and characterized by SEM, light microscopy and permeation of gases, prevailingly of He. The accessibility of sililicalite-1 pores prior to embedding and after embedding into polymeric matrices was studied by an iodine indicator technique. The permeability of membranes for gases was measured using a semi-open permeation apparatus with a small volume. Helium permeability depended on filler content and increased monotonously with the increasing content of filler. There were, however, significant deviations of the permeability dependences on filler content from shapes predicted by Bruggeman’s model. The qualitative explanation of the data disagreement with the model was proposed based on a stratification of mixed matrix membranes found by SEM

Testate Amoebae Examined by Confocal and Two-Photon Microscopy: Implications for Taxonomy and Ecophysiology

Testate amoebae (TA) are a group of free-living protozoa, important in ecology and paleoecology. Testate amoebae taxonomy is mainly based on the morphological features of the shell, as examined by means of light microscopy or (environmental) scanning electron microscopy (SEM/ESEM). We explored the potential applications of confocal laser scanning microscopy (CLSM), two photon excitation microscopy (TPEM), phase contrast, differential interference contrast (DIC Nomarski), and polarization microscopy to visualize TA shells and inner structures of living cells, which is not possible by SEM or environmental SEM. Images captured by CLSM and TPEM were utilized to create three-dimensional (3D) visualizations and to evaluate biovolume inside the shell by stereological methods, to assess the function of TA in ecosystems. This approach broadens the understanding of TA cell and shell morphology, and inner structures including organelles and endosymbionts, with potential implications in taxonomy and ecophysiolog

Input of easily available organic C and N stimulates microbial decomposition of soil organic matter in arctic permafrost soil

Rising temperatures in the Arctic can affect soil organic matter (SOM) decomposition directly and indirectly, by increasing plant primary production and thus the allocation of plant-derived organic compounds into the soil. Such compounds, for example root exudates or decaying fine roots, are easily available for microorganisms, and can alter the decomposition of older SOM ("priming effect"). We here report on a SOM priming experiment in the active layer of a permafrost soil from the central Siberian Arctic, comparing responses of organic topsoil, mineral subsoil, and cryoturbated subsoil material (i.e., poorly decomposed topsoil material subducted into the subsoil by freeze-thaw processes) to additions of 13C-labeled glucose, cellulose, a mixture of amino acids, and protein (added at levels corresponding to approximately 1% of soil organic carbon). SOM decomposition in the topsoil was barely affected by higher availability of organic compounds, whereas SOM decomposition in both subsoil horizons responded strongly. In the mineral subsoil, SOM decomposition increased by a factor of two to three after any substrate addition (glucose, cellulose, amino acids, protein), suggesting that the microbial decomposer community was limited in energy to break down more complex components of SOM. In the cryoturbated horizon, SOM decomposition increased by a factor of two after addition of amino acids or protein, but was not significantly affected by glucose or cellulose, indicating nitrogen rather than energy limitation. Since the stimulation of SOM decomposition in cryoturbated material was not connected to microbial growth or to a change in microbial community composition, the additional nitrogen was likely invested in the production of extracellular enzymes required for SOM decomposition. Our findings provide a first mechanistic understanding of priming in permafrost soils and suggest that an increase in the availability of organic carbon or nitrogen, e.g., by increased plant productivity, can change the decomposition of SOM stored in deeper layers of permafrost soils, with possible repercussions on the global climate.Austrian Science Fund (FWF)/CryoCAR

Hepatic Gene Expression Profiles Differentiate Steatotic and Non-steatotic Grafts in Liver Transplant Recipients

Background: Liver transplantation leads to non-alcoholic fatty liver disease or non-alcoholic steatohepatitis in up to 40% of graft recipients. The aim of our study was to assess transcriptomic profiles of liver grafts and to contrast the hepatic gene expression between the patients after transplantation with vs. without graft steatosis.Methods: Total RNA was isolated from liver graft biopsies of 91 recipients. Clinical characteristics were compared between steatotic (n = 48) and control (n = 43) samples. Their transcriptomic profiles were assessed using Affymetrix HuGene 2.1 ST Array Strips processed in Affymetrix GeneAtlas. Data were analyzed using Partek Genomics Suite 6.6 and Ingenuity Pathway Analysis.Results: The individuals with hepatic steatosis showed higher indices of obesity including weight, waist circumference or BMI but the two groups were comparable in measures of insulin sensitivity and cholesterol concentrations. We have identified 747 transcripts (326 upregulated and 421 downregulated in steatotic samples compared to controls) significantly differentially expressed between grafts with vs. those without steatosis. Among the most downregulated genes in steatotic samples were P4HA1, IGF1, or fetuin B while the most upregulated were PLIN1 and ME1. Most influential upstream regulators included HNF1A, RXRA, and FXR. The metabolic pathways dysregulated in steatotic liver grafts comprised blood coagulation, bile acid synthesis and transport, cell redox homeostasis, lipid and cholesterol metabolism, epithelial adherence junction signaling, amino acid metabolism, AMPK and glucagon signaling, transmethylation reactions, and inflammation-related pathways. The derived mechanistic network underlying major transcriptome differences between steatotic samples and controls featured PPARA and SERPINE1 as main nodes.Conclusions: While there is a certain overlap between the results of the current study and published transcriptomic profiles of non-transplanted livers with steatosis, we have identified discrete characteristics of the non-alcoholic fatty liver disease in liver grafts potentially utilizable for the establishment of predictive signature

Design and implementation of mechatronic hand

Cílem bakalářské práce je vytvoření 3D modelu mechatronické končetiny s důrazem na jednoduchost a možnou výrobu s přiměřenými náklady, funkčnost a zvládnutí základních typů úchopů lidské ruky. 3D modelová sestava bude tvořena z dílů a podsestav vytvořených v nástroji Autodesk Inventor Professional 2015 Studentské verzi. Dalším tématem dané práce je přehled a popis využití přesného 3D modelování, použití různých typů kloubů, pohonných systémů a možnost řízení pomocí prototypových systémů.The goal of this bachelor thesis is the creation of the mechatronic limb 3D model with the simplicity on spotlight and possible production with appropriate cost as well a functionality and mastering the basic grasps of the human hand. The 3D model will be made from parts and subassemblies created in the Autodesk Inventor Professional-student version tool. The other topic of this work is overview and use of accurate 3D modeling, usage of different kinds of joints and drive systems as well as possibility to drive with prototype systems.Fakulta elektrotechniky a informatikyCílem bakalářské práce je vytvoření 3D modelu mechatronické končetiny s důrazem na jednoduchost a možnou výrobu s přiměřenými náklady, funkčnost a zvládnutí základních typů úchopů lidské ruky. 3D modelová sestava bude tvořena z dílů a podsestav vytvořených v nástroji Autodesk Inventor Professional 2015 Studentské verzi. Dalším tématem dané práce je přehled a popis využití přesného 3D modelování, použití různých typů kloubů, pohonných systémů a možnost řízení pomocí prototypových systémů. Obecně je možné prohlásit, že student, za více než rok, zpracování své bakalářské práce vytvořil velké množství odborné práce

Mutation Screening in Familial Cardiovascular Diseases

Introduction: Hypertrophic cardiomyopathy is a congenital cardiac disease with autosomal dominant pattern of inheritance and incomplete penetrance. With the knowledge of the responsible genes, the ability to detect the underlying genetic change and with the study of functional analysis of defected protein, we might be able to determine whether specific genotypes lead to different phenotypes. Aims of Study: To comprehensively analyze the mechanism of genesis of hypertrophic cardiomyopathy in Czech patients afflicted with this disorder from molecular genetic point of view (MYH7, TNNT2 gene) to functional analysis of the 3D molecular model of defected β-myosin heavy chain protein in silico. Beside these aims of the study, the reduction of production of inflammatory aggregates in the cardiovascular system was studied in patients with type 2 diabetes mellitus. The reason of this study was to look into possibilities of therapeutical effect on selected cardiovascular risks in patients with hypertrophic cardiomyopathy simultaneously suffering from type 2 diabetes mellitus. Both of these groups of patients have substantially increased risk of cardiovascular diseases due to development of premature atherosclerosis. Material and Methods: A total of 170 probands were enrolled in this study of MYH7 gene. DNA..