text: Search Results: 1 - 10 of 205729 matches for " Tom Mari?n "
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  The Mitochondrial Complex I Activity Is Reduced in Cells with Impaired Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) Function
  Angel G. Valdivieso, Mariángeles Clauzure, María C. Marín, Guillermo L. Taminelli, María M. Massip Copiz, Francisco Sánchez, Gustavo Schulman, María L. Teiber, Tomás A. Santa-Coloma
  PLOS ONE , 2012, DOI: 10.1371/journal.pone.0048059
  Abstract: Cystic fibrosis (CF) is a frequent and lethal autosomal recessive disease. It results from different possible mutations in the CFTR gene, which encodes the CFTR chloride channel. We have previously studied the differential expression of genes in CF and CF corrected cell lines, and found a reduced expression of MTND4 in CF cells. MTND4 is a mitochondrial gene encoding the MTND4 subunit of the mitochondrial Complex I (mCx-I). Since this subunit is essential for the assembly and activity of mCx-I, we have now studied whether the activity of this complex was also affected in CF cells. By using Blue Native-PAGE, the in-gel activity (IGA) of the mCx-I was found reduced in CFDE and IB3-1 cells (CF cell lines) compared with CFDE/6RepCFTR and S9 cells, respectively (CFDE and IB3-1 cells ectopically expressing wild-type CFTR). Moreover, colon carcinoma T84 and Caco-2 cells, which express wt-CFTR, either treated with CFTR inhibitors (glibenclamide, CFTR(inh)-172 or GlyH101) or transfected with a CFTR-specific shRNAi, showed a significant reduction on the IGA of mCx-I. The reduction of the mCx-I activity caused by CFTR inhibition under physiological or pathological conditions may have a profound impact on mitochondrial functions of CF and non-CF cells.
  Ond?ej ?míd,Anna Matu?ková,Simon R. Harris,Tomá? Ku?era,Marián Novotny,Lenka Horváthová,Ivan Hrdy,Eva Kutějová,Robert P. Hirt,T. Martin Embley,Ji?í Janata,Jan Tachezy
  PLOS Pathogens , 2008, DOI: 10.1371/journal.ppat.1000243
  Abstract: Mitochondrial processing peptidases are heterodimeric enzymes (α/βMPP) that play an essential role in mitochondrial biogenesis by recognizing and cleaving the targeting presequences of nuclear-encoded mitochondrial proteins. The two subunits are paralogues that probably evolved by duplication of a gene for a monomeric metallopeptidase from the endosymbiotic ancestor of mitochondria. Here, we characterize the MPP-like proteins from two important human parasites that contain highly reduced versions of mitochondria, the mitosomes of Giardia intestinalis and the hydrogenosomes of Trichomonas vaginalis. Our biochemical characterization of recombinant proteins showed that, contrary to a recent report, the Trichomonas processing peptidase functions efficiently as an α/β heterodimer. By contrast, and so far uniquely among eukaryotes, the Giardia processing peptidase functions as a monomer comprising a single βMPP-like catalytic subunit. The structure and surface charge distribution of the Giardia processing peptidase predicted from a 3-D protein model appear to have co-evolved with the properties of Giardia mitosomal targeting sequences, which, unlike classic mitochondrial targeting signals, are typically short and impoverished in positively charged residues. The majority of hydrogenosomal presequences resemble those of mitosomes, but longer, positively charged mitochondrial-type presequences were also identified, consistent with the retention of the Trichomonas αMPP-like subunit. Our computational and experimental/functional analyses reveal that the divergent processing peptidases of Giardia mitosomes and Trichomonas hydrogenosomes evolved from the same ancestral heterodimeric α/βMPP metallopeptidase as did the classic mitochondrial enzyme. The unique monomeric structure of the Giardia enzyme, and the co-evolving properties of the Giardia enzyme and substrate, provide a compelling example of the power of reductive evolution to shape parasite biology.
  TECHNOLOGICAL CHARACTERISTICS OF THE ZLATá BA A ORES
  Ko?uth Marián
  Acta Montanistica Slovaca , 1997,
  Abstract: The main processing interest of examined Zlatá Baňa polymetalic ores was focused on copper-lead-zinc minerals with precious metals and trace elements. Gold occurrin a native form or as an isomorphism in pyrite. The role of inclusions of own Ag-minerals was inflated by geologist, but a prevailing amount of silver is isomorphous in galena and argentotetrahedrite. Almost no possibility to concentrating discrete silver minerals was proved technologically. In galena, an interesting content of Se and Te was registered. Among trace elements, a higher content of cadmium folows exclusively the content of zinc in blende.
  Influence of structural backlash and friction in command system on the aircraft flutter
  Mari?i? N.
  Theoretical and Applied Mechanics , 2004, DOI: 10.2298/tam0404317m
  Abstract: Experience has shown that aircraft structures are generally affected by structural nonlinearities. The focus in this paper is concentrated on backlash and friction described in hysteresis loop of the classical aircraft command systems and their influence on flutter of aircraft. Based on AGARD No. 665 in paper is done nonlinear flutter velocity analysis in function of backlash and friction in the classical command system of aircraft. Unsteady aerodynamic forces are calculated based on well known Doublet- Lattice Method (DLM). Structural input data are taken from AGARD No. 665. Flutter eigenvalues are obtained by modified k-method. The flutter model of nonlinear aircraft structure is developed on base of harmonic linearization. The aim of paper is to achieve useful and relatively reliable tool for critical observations on different recommendations given in the various airworthiness regulations for nonlinear characteristics of hysteresis loops in the classical command systems of aircrafts. .
  Review of reasearch and technical development focused
  Slavkovsky Marián
  Abstract: Treatment of flotation tetrahedrite concentrates produced from the of ore mined in the Rudňany and Ro ňava ore deposits is a very complex technological problem. This problem has not been solved succesfuly so far. The presence and quality of undesired metal components such as antimony and mercury in the product of a wet ore dressing is a limiting factor for subsequent metalurgical process to obtain pure metal copper and/or silver in copper smelter plants. This factor has been the principal reason of a great effort provided in this respects by both, manufacturers and reaserchers mainly in the last 25 years. This article is focused on the summary of mentioned activities.
  Steam Turbine Assisted Cogeneration systems
  ?arisky Marián
  Abstract: Searching for the best way of improving using systems of production electrical energy and heat is part of an intensive development in the field of energetic. Using steam turbines in the cogeneration system is very important step at increasing the effection not only of the whole system, but of the gas turbine as well. The advantages and the characteristic features of the system are shown in the article.
  Prospects of utilizing raw material reserves of the Ro ňava ore field
  Jan?ura Marián
  Abstract: Differencies in a mineralogical composition of veins at the Ro ňava ore field condition prospects of its utilitation. Monomineral siderite veins in the western part are not perspective from the point of view of next utilisation. Komplex Fe, Cu, Ag ores are conveniently exploited only in a part of the Strieborná vein reserves.
  IDEOLOGICAL SOURCES OF THE ECONOMIC DEMOCRACY AND ITS HISTORICAL DEVELOPMENT
  Abstract: In the paper, the author elucidates the fundamental characteristics of theeconomic democracy. Therefore, the concept is also introduced through its historicaldevelopment beginning in the 18th century up to present day. Particular space isdevoted to the development of the concept in both theory and practice of the formerCzechoslovakia. The focus is on the ideological diversity of the authors developing theconcept of economic democracy, as well as the heterogeneity of the interpretations ofits content.