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  • 1
    Electronic Resource
    Electronic Resource
    Enhanced G-protein activation by a mixture of Aβ(25–35), Aβ(1–40/42) and zinc (2004)
    Oxford, UK : Blackwell Science Ltd
    Journal of neurochemistry 89 (2004), S. 0 
    Details
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: β-Amyloid peptides (Aβs) bind to several G-protein coupled receptor proteins and stimulate GTPase activity in neurons. In this study we determined the effects of Aβ(1–42), Aβ(1–40), Aβ(25–35) and their mixtures on [35S]GTP binding in rat brain cortical membranes in the absence and presence of zinc. We found that the Aβs alone induced a concentration-dependent activation of G-proteins (IC50∼ 10−6 m), while aggregated Aβ fibrils only affected GTP binding at concentrations above 10−5 m. Mixing Aβ(25–35) with Aβ(1–42) or Aβ(1–40) induced a several-fold increase in GTP-binding. This potentiation followed a bell shaped curve with a maximum at 50 : 50 ratios. No potentiating effect could be seen by mixing Aβ(1–40) and Aβ(1–42) or highly aggregated Aβs. Zinc had no effect on Aβ(1–40/42) but strongly potentiated the Aβ(25–35) or the mixed peptides-induced GTP-binding. Changes in secondary structure accompanied the mixed peptides or the peptide/zinc complexes induced potentiation, revealing that structural alterations are behind the increased biological action. These concentration dependent potentiating effects of zinc and the peptide mixtures could be physiologically important at brain regions where peptide fragments and/or zinc are present at elevated concentrations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1471-4159.2004.02427.x
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  • 2
    Electronic Resource
    Electronic Resource
    Alkaline lamprophyre and related dyke rocks in NE Transdanubia, Hungary: The Alcsutdoboz-2 (AD-2) borehole (1993)
    Springer
    Mineralogy and petrology 47 (1993), S. 127-148 
    Details
    ISSN: 1438-1168
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Description / Table of Contents: Zusammenfassung Der Kern der Bohrung Alcsutdoboz-2 (AD-2) enthält zwölf magmatische Gänge, die zu der jung-kretazischen Lamprophyr-Karbonatit-Assoziation des nordöstlichen Transdanubiens in Ungarn gehören. Petrographisch gesehen gehören elf Gänge zu den alkalischen Lamprophyren (hauptsächlich Monchiquit), und der Rest kann als Karbonatit bezeichnet werden. Die Lamprophyrgänge sind in ihrer Hauptelementzusammensetzung sowohl alkalischen Lamprophyren wie ultramafschen Lamprophyren ähnlich. Der Karbonatitgang hingegen zeigt Parameter, die denen von Karbonatiten teilweise, aber nicht durchwegs, ähnlich sind. Beide Typen der AD-2-Gänge zeigen höhere LILE-Gehalte als ultramafische Lamprophre und Kimberlite, unterscheiden sich aber deutlich vom durchschnittlichen Karbonatit. Auf der Basis der Seltenen ErdVerteilung, werden Kristallfraktionierung (hauptsächlich von Olivin) und Abtrennung einer Karbonatphase von lamprophyrischen Magma als Vorgänge gesehen, die für die Entstehung der Karbonatit-Gänge relevant sind. Diese Aspekte und die Zonierung der Zusammensetzungen von Klinopyroxen und Glimmer weisen auf eine komplexe Kristallisationsgeschichte dieser Gänge hin. Sehr wahrscheinlich ist die lamprophyrische Ausgangsschmelze durch eine geringfügige teilweise Aufschmelzung von metasomatisiertem Mantel entstanden.
    Notes: Summary The Alcsutdoboz-2 (AD-2) core contains 12 magmatic dykes which belong to the Late Cretaceous lamprophyric-carbonatitic association of NE Transdanubia, Hungary. Petrographically, 11 dykes can be considered alkaline lamprophyre (mainly monchiquite), and the remainder might be called carbonatite. The lamprophyre dykes are similar to both alkaline lamprophyres and ultramafic lamprophyres in major element composition, whereas the carbonatite dyke has some features that are similar to carbonatites but others that are dissimilar. Nevertheless, both of the two types of AD-2 dykes possess higher LILE content than the ultramafc lamprophyres and kimberlites, but strongly differ from average carbonatite. Based on the REE pattern, crystal fractionation (mainly of olivine) and separation of a carbonate phase from the parental lamprophyric magma are proposed for genesis of the carbonatite dyke. These characteristics and the compositional zoning of clinopyroxene and mica suggest a complex crystallization history for these dykes. The likeliest origin for the parental lamprophyric melt is through a very small degree of partial melting of metasomatized mantle.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01161563
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  • 3
    Electronic Resource
    Electronic Resource
    Analysis of actinides in the primary coolant of a WWER-440 type reactor (1993)
    Springer
    Journal of radioanalytical and nuclear chemistry 170 (1993), S. 399-409 
    Details
    ISSN: 1588-2780
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract A simple and effective method has been developed for the determination of the transuranium isotopes in primary coolant samples of WWER-440 type reactors. Membrane filters containing undissolved particles from about one liter coolant were destroyed by mineral acids, then americium-curium isotopes and neptunium-plutonium isotopes were coprecipitated sequentially with NdF3 based on their different redox behavior. Alpha-spectra were determined by silicon semiconductor detectors connected to multichannel analyzers. Activity ratios measured in a reactor unit with a failed fuel element were compared with calculated values of the same type of reactor under similar conditions. Parameters of the defective fuel (burnup, original enrichment) could be estimated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02041476
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  • 4
    Electronic Resource
    Electronic Resource
    Inventory determination of low and intermediate level radioactive waste of Paks Nuclear Power Plant origin (1996)
    Springer
    Journal of radioanalytical and nuclear chemistry 211 (1996), S. 443-451 
    Details
    ISSN: 1588-2780
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract In the execution of disposal of low and intermediate level radioactive wastes, it is important to evaluate accurately the kind and quantity of each radionuclide in the wastes. For such an evaluation, correlation of non-gamma-emitting nuclides based on gamma-emitting nuclides is recommended and regarded as a practical method. This method necessitates a completion of a highly accurate and reliable nondestructive assay system of gamma-emitting nuclides for practical use. In 1992, in support of the new waste disposal program in Hungary, Paks NPP initiated a waste characterization program to determine the radiological properties of its radwastes. A segmented gamma scanning system has been set up to measure the gamma-emitting nuclides in 200 litre low level drums following in-drum compaction. In the framework of the program a radiochemical analysis sub-program was started to determine the long-lived non-gamma emitting radionuclides, mainly those listed in the US regulatory document (10CFR61). The radionuclides of interest have been3H,14C,90Sr,55Fe,59Ni,99Tc,129I and TRUs. Sample preparation techniques and measurement methods have been selected and used. Newly developed or adopted methods have been tested on real liquid radwaste streams such as concentrates, ion-exchange resin and sludge. The measurements taken so far have revealed brand new information and data on radiological composition of waste of WWER-type reactors. In the next stage of the characterisation program attempt will be made for providing correlation factors between the gamma and non-gamma-emitting radionuclides in different waste streams. Short description of the methods and results on waste inventory are given by highlighting the problem areas.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02039710
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  • 5
    Electronic Resource
    Electronic Resource
    Characterisation of biological RMs for potential use in human brain analysis (1993)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 345 (1993), S. 340-342 
    Details
    ISSN: 1618-2650
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary In order to investigate the precision and accuracy obtainable with instrumental neutron activation analysis (INAA) and inductively coupled plasma atomic emission spectrometry (ICP-AES), five different biological reference materials were analyzed. Four of them originated from the US National Institute of Standards and Technology (NIST) (Bovine Liver (SRM 1577; 1577/a; 185/A), Orchard Leaves (SRM 1571)) and one of them came from the International Atomic Energy Agency (IAEA) (Animal muscle (H-4)). The decomposition efficiency of microwave acid digestion was examined in comparison to digestions carried out in a Parrbomb. Five to ten subsamples of each material were subjected to the two digestion procedures and the solutions were analyzed by ICP-AES. The dried samples were analyzed by INAA. Up to 16 elements (Al, B, Ca, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, S, Zn) were determined in various materials.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00322626
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