Search Results - (Author, Cooperation:K. Valentin)

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  1. 1
    Staff View
    Publication Date:
    2013-06-14
    Publisher:
    Nature Publishing Group (NPG)
    Print ISSN:
    0028-0836
    Electronic ISSN:
    1476-4687
    Topics:
    Biology
    Chemistry and Pharmacology
    Medicine
    Natural Sciences in General
    Physics
    Keywords:
    Calcification, Physiologic ; Calcium/metabolism ; Carbonic Anhydrases/genetics/metabolism ; Ecosystem ; Genome/*genetics ; Haptophyta/classification/*genetics/*isolation & purification/metabolism ; Oceans and Seas ; Phylogeny ; Phytoplankton/*genetics ; Proteome/genetics ; Seawater
    Published by:
    http://www.nature.com/

    Latest Papers from Table of Contents or Articles in Press
  2. 2
    Valentin, K.

    Amsterdam : Elsevier
    Staff View
    ISSN:
    0027-5107
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Biology
    Medicine
    Type of Medium:
    Electronic Resource
    URL:
    http://linkinghub.elsevier.com/retrieve/pii/0027-5107(75)90087-1

    Articles: DFG German National Licenses
  3. 3
    Valentin, K. ; Taurins, A.

    Amsterdam : Elsevier
    Staff View
    ISSN:
    0040-4039
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Chemistry and Pharmacology
    Type of Medium:
    Electronic Resource
    URL:
    http://linkinghub.elsevier.com/retrieve/pii/S0040-4039(01)82839-2

    Articles: DFG German National Licenses
  4. 4
    Valentin, K. ; Zetsche, K.
    Springer
    Published 1990
    Staff View
    ISSN:
    1432-0983
    Keywords:
    Cyanelles ; Endosymbiosis ; Plastid evolution ; Ribulose-1,5-bisphosphate carboxylase/oxygenase
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Biology
    Notes:
    Abstract The gene (rbcL) for the large subunit (LSU) of Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) from Cyanophora paradoxa was cloned and the nucleotide sequence determined. Sequence homologies to rbcL genes from other sources clearly indicated a close phylogenetic relationship between the photosynthetic organelles of Cyanophora (cyanelles), green chloroplasts and cyanobacteria. Our data support the hypothesis that the cyanelles of Cyanophora may represent a closely related, but independent, side line to chloroplast evolution. Cyanelles and rhodoplasts or phaeoplasts seem not to be related.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1007/BF00318380

    Articles: DFG German National Licenses
  5. 5
    Mikhailov, Oleg V. ; Polovnyak, Valentin K.
    Springer
    Published 1990
    Staff View
    ISSN:
    1434-4475
    Keywords:
    Immobilized matrix ; Complexing ; Thin gelatin layer
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Chemistry and Pharmacology
    Description / Table of Contents:
    Zusammenfassung Es wurden Komplexierungsprozesse auf immobilisierten Matrices, die von Ni(II)-Hexacyanoferrat(II) und Lösungen verschiedener Stickstoff-Schwefel-Liganden erhalten wurden, in dünnen Gelatin-Schichten untersucht. Mit einer Ni2[Fe(CN)6]-Matrix wurde festgestellt, daß der Komplexierungsprozeß nach einem S N 2 -Mechanismus verläuft. Es werden die entsprechenden Reaktionsschemata angegeben. Beispiele für den kinetischen Verlauf für bestimmte „Hexacyanoferrat(II)-Ni(II)-Ligand“-Systeme werden präsentiert.
    Notes:
    Summary Complexing processes occurring between immobilized matrices obtained from Ni(II) hexacyanoferrates(II) and solutions of various nitrogen-sulfur-containing chelating ligands in thin gelatin layers have been studied. With Ni2[Fe(CN)6]-matrix, the complexing process is found to proceed according to a S N 2 -mechanism. The schemes of the processes in each of the above matrices are given. Examples of kinetic curves for particular systems “hexacyanoferrate(II) nickel(II)-ligand” are presented.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1007/BF00809762

    Articles: DFG German National Licenses
  6. 6
    Lindner, Mark D. ; Gribkoff, Valentin K.
    Springer
    Published 1992
    Staff View
    ISSN:
    1432-2072
    Keywords:
    BMY 21502 ; Age ; Learning ; Cognitive dysfunction ; Morris water maze
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Medicine
    Notes:
    Abstract In the present study we have examined the effects of oral administration of BMY 21502, a potential cognition enhancing drug, on the impaired Morris water task performance of 16–18 month old F-344 rats. BMY 21502 did not affect swim speeds or performance on the first trial of each day, but it did increase the rate of acquisition and initial retention, resulting in decreased swim distances on the second trial of each day. This increased rate of acquisition was dose-dependent, increasing to a peak at 5.0 mg/kg; the effect was decreased at 10 mg/kg, but still above control values. These results suggest that BMY 21502 is orally active over a broad range of doses, and lend further support for its potential as a therapeutic agent for the treatment of dementia.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1007/BF02245260

    Articles: DFG German National Licenses
  7. 7
    Gribkoff, Valentin K. ; Ashe, John H.
    Springer
    Published 1984
    Staff View
    ISSN:
    1573-6830
    Keywords:
    hippocampus ; pyramidal cells ; dopamine ; synaptic plasticity
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Biology
    Notes:
    Summary 1. Extracellular recording techniques were used to study the effects of dopamine on postactivation excitability of rat area CA1 hippocampal neurons maintainedin vitro. Population spikes were elicited by delivery of conditioning and test stimulus pulses to afferent fibers. The interval between the conditioning and test volley was set to separate delivery of stimuli by 10 to 80 msec. The effect of superfusion or microtopical application of dopamine (DA) on population responses to test stimulus pulses was studied. 2. When paired stimulus volleys, separated by brief intervals (up to 40 msec), were delivered to afferent fibers, paired-pulse suppression (PPS) was indicated by the amplitude of the population spike elicited by the test volley being smaller than that elicited by the conditioning volley. When paired volleys were separated by longer intervals (40 to 80 msec), the response elicited by the test volley was larger in amplitude than that elicited by the conditioning volley, indicating paired-pulse facilitation (PPF). 3. Following exposure to DA, the amplitude of the population response elicited by the conditioning volley was larger than the amplitude before exposure to DA. This effect was long-lasting, enduring for tens of minutes. However, when the amplitude of the conditioning population response was held constant, the PPS was decreased, indicating disinhibition. 4. It is suggested that dopamine produces a long-lasting attenuation of an intervening inhibitory influence onto CA1 pyramidal neurons.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1007/BF00711003

    Articles: DFG German National Licenses