29 resultados para MANGANESE 54

em BORIS: Bern Open Repository and Information System - Berna - Suiça


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• Background and Aims The uptake, translocation and redistribution of the heavy metals zinc, manganese, nickel, cobalt and cadmium are relevant for plant nutrition as well as for the quality of harvested plant products. The long-distance transport of these heavy metals within the root system and the release to the shoot in young wheat (Triticum aestivum ‘Arina’) plants were investigated. • Methods After the application of 65Zn, 54Mn, 63Ni, 57Co and 109Cd for 24 h to one seminal root (the other seminal roots being excised) of 54-h-old wheat seedlings, the labelled plants were incubated for several days in hydroponic culture on a medium without radionuclides. • Key Results The content of 65Zn decreased quickly in the labelled part of the root. After the transfer of 65Zn from the roots to the shoot, a further redistribution in the phloem from older to younger leaves was observed. In contrast to 65Zn, 109Cd was released more slowly from the roots to the leaves and was subsequently redistributed in the phloem to the youngest leaves only at trace levels. The content of 63Ni decreased quickly in the labelled part of the root, moving to the newly formed parts of the root system and also accumulating transiently in the expanding leaves. The 54Mn content decreased quickly in the labelled part of the root and increased simultaneously in leaf 1. A strong retention in the labelled part of the root was observed after supplying 57Co. • Conclusions The dynamics of redistribution of 65Zn, 54Mn, 63Ni, 57Co and 109Cd differed considerably. The rapid redistribution of 63Ni from older to younger leaves throughout the experiment indicated a high mobility in the phloem, while 54Mn was mobile only in the xylem and 57Co was retained in the labelled root without being loaded into the xylem.

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Benzodifuran-functionalised pyrene and anthracene fluorophores 1 and 2 were obtained in reasonable yields. Their single crystal structures, electrochemical, optical absorption, and fluorescence characteristics have been described. They show strong luminescence with high quantum yields of 0.53 for 1 and 0.48 for 2. Magnetic measurements for the 2D coordination polymer [Mn(Pht(Pyz(H2O)2]n (1), in which metal centres are linked together by pyrazine (Pyz) and 1,6-bridging o-phthalate ligand (Pht2-), revealed antiferromagnetic interactions between Mn(II) ions.

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Chronic alcohol consumption is a major risk factor for the development of chronic pancreatitis. However, chronic pancreatitis occurs only in a minority of heavy drinkers. This variability may be due to yet unidentified genetic factors. Several enzymes involved in the degradation of reactive oxidants and xenobiotics, such as glutathione-S-transferase P1 (GSTP1) and manganese-superoxide dismutase (MnSOD) reveal functional polymorphisms that affect the antioxidative capacity and may therefore modulate the development of chronic pancreatitis and long-term complications like endocrine and exocrine pancreatic insufficiency. Two functional polymorphisms of the MnSOD and the GSTP1 gene were assessed by polymerase chain reaction and restriction fragment length polymorphism in 165 patients with chronic alcoholic pancreatitis, 140 alcoholics without evidence of pancreatic disease and 160 healthy control subjects. The distribution of GSTP1 and MnSOD genotypes were in Hardy-Weinberg equilibrium in the total cohort. Genotype and allele frequencies for both genes were not statistically different between the three groups. Although genotype MnSOD Ala/Val was seemingly associated with the presence of exocrine pancreatic insufficiency, this subgroup was too small and the association statistically underpowered. None of the tested genotypes affected the development of endocrine pancreatic insufficiency. Polymorphisms of MnSOD and GSTP1 are not associated with chronic alcoholic pancreatitis. The present data emphasize the need for stringently designed candidate gene association studies with well-characterized cases and controls and sufficient statistical power to exclude chance observations.

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