Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Der Radiologe 38 (1998), S. 578-585 
    ISSN: 1432-2102
    Keywords: Schlüsselwörter Phlebographie ; Doppler- und Duplexsonographie ; Extremitätenvenen ; Qualitätssicherung ; Key words Phlebography ; Duplex-ultrasound ; Extremity veins ; Quality standards
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary By interdisciplinary cooperation with the German Societies for Angiology, Phlebology and Vascular Surgery, recommendations have been worked out which address the indication of phlebography of the veins of the extremities and which define the quality standards of phlebographic techniques. The specific clinical questions in varicose syndrome, acute thrombosis and postthrombotic syndrome have to be answered by employing adequate phlebographic technique, documentation, and description of relevant morphologic and functional findings.
    Notes: Zusammenfassung In Zusammenarbeit mit den Fachgesellschaften Deutsche Gesellschaft für Angiologie, Deutsche Gesellschaft für Phlebologie und Deutsche Gesellschaft für Gefäßchirurgie wurden Empfehlungen zur Indikationsstellung, Untersuchungstechnik und Qualitätssicherung der Extremitätenphlebographie erstellt. Für die speziellen klinischen Fragestellungen beim Varikosesyndrom, bei der akuten Phlebothrombose und beim Postthrombotischen Syndrom werden die Qualitätsmerkmale für die Dokumentation und Befundung nach morphologischen und funktionellen Gesichtspunkten tabellarisch zusammengefaßt.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1434-4475
    Keywords: Neutral networks ; Percolation of sequence space ; RNA folding ; RNA secondary structures ; Shape space covering
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Die Beziehungen zwischen RNA-Sequenzen und ihren Sekundärstrukturen werden durch vollständiges Falten allerGC- undAU-Sequenzen mit Kettenlängen bis zun=30 untersucht. Die aus der Informatik bekannte Technik derTries wird zur ökonomischen Datenspeicherung und für rasches Retrieval der gespeicherten Information angewendet. Die berechneten Strukturdaten werden durch vollständiges Abzählen ausgewertet. Sie dienen unter anderem als eine exakte Referenz zum Testen analytischer Resultate aus mathematischen Modellen sowie zur Überprüfung der Ergebnisse statistischer Probennahmen. Verschiedene neuartige Konzepte zur Behandlung der Zusammenhänge zwischen RNA-Sequenzen und Sekundärstrukturen wurden anhand der gewonnenen Daten eingehend untersucht. Unter ihnen befinden sich die Struktur derneutralen Netzwerke (die Gesamtheit der RNA-Sequenzen, die eine bestimmte Struktur ausbilden), diePerkolation des Sequenzraumes durch neutrale Netzwerke sowie das Prinzip derErfassung des Strukturraumes durch einen kleinen Ausschnitt des Sequenzraumes. Die durch vollständiges Abzählen erhaltenen Daten werden mit den analytischen Ergebnissen eines auf der Theorie der Zufallsgraphen aufbauenden Modells verglichen. Dieses Modell gibt die generischen Eigenschaften von Sequenz-Struktur-Relationen wieder, welche lediglich aus der Existenz einer Paarungslogik resultieren. Differenzen zwischen den numerischen und den analytischen Resultaten können als Konsequenzen der spezifischen biophysikalischen Eigenschaften von RNA-Molekülen interpretiert werden.
    Notes: Summary The relations between RNA sequences and secondary structures are investigated by exhaustive folding of allGC andAU sequences with chain lengths up to 30. The technique oftries is used for economic data storage and fast retrieval of information. The computed structural data are evaluated through exhaustive enumeration and used as an exact reference for testing analytical results derived from mathematical models and sampling based on statistical methods. Several new concepts of RNA sequence to secondary structure mappings are investigated, among them the structure ofneutral networks (being sets of RNA sequences folding into the same structure),percolation of sequence space by neutral networks, and the principle ofshape space covering. The data of exhaustive enumeration are compared to the analytical results of arandom graph model that reveals the generic properties of sequence to structure mappings based on some base pairing logic. The differences between the numerical and the analytical results are interpreted in terms of specific biophysical properties of RNA molecules.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1434-4475
    Keywords: Neutral networks ; Random graphs ; RNA secondary structures ; Zipf's law
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Die globalen Benziehungen zwischen RNA-Sequenzen und Sekundärstrukturen werden als Abbildungen aus einem Raum aller Sequenzen in einen Raum aller Strukturen aufgefaßt. Diese Abbildungen werden durch Falten aller binären Sequenzen desGC-undAU-Alphabets mit Kettenlängen bis zun=30 untersucht. Die berechneten Strukturdaten werden durch vollständiges Abzählen ausgewertet und als eine exakte Referenz zum Überprüfen analytischer Resultate aus mathematischen Modellen sowie zum Testen statistisch erhobener Proben verwendet. Einige neuartige Konzepte zur Beschreibung der Beziehungen zwischen Sequenzen und Strukturen werden eingehend untersucht, unter ihnen der Begriff derneutralen Netzwerke. Ein neutrales Netzwerk besteht aus allen Sequenzen, die eine bestimmte Struktur ausbilden. Vollständiges Abzählen ermöglicht beispielsweise die Bestimmung aller Strukturen minimaler freier Energie in Abhängigkeit von der Kettenlänge ebenso wie die Bestimmung der Häufigkeitsverteilungen der Strukturen bei konstanten Kettenlängen. Die letzteren folgen einer verallgemeinerten FormZipfschen Gesetzes.
    Notes: Summary Global relations between RNA sequences and secondary structures are understood as mappings from sequence space into shape space. These mappings are investigated by exhaustive folding of allGC andAU sequences with chain lengths up to 30. The computed structural data are evaluated through exhaustive enumeration and used as an exact reference for testing analytical results derived from mathematical models and sampling based on statistical methods. Several new concepts of RNA sequence to secondary structure mappings are investigated, among them that ofneutral networks (being sets of sequences folding into the same structure). Exhaustive enumeration allows to test several previously suggested relations: the number of (minimum free energy) secondary structures as a function of the chain length as well as the frequency distribution of structures at constant chain length (commonly resulting in generalized forms ofZipf's law).
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 61 (1997), S. 683-688 
    ISSN: 0020-7608
    Keywords: Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Quantum chemical calculations using the density functional theory were performed to model the mechanism of selective catalytic reduction of NO by NH3 on a supported vanadium oxide monolayer. In the first step, the adsorption of NH3 on a bimetallic cluster representative of vanadium oxide, containing a terminal V—O adjacent to a V—OH group, was investigated. The calculations indicate that NH3 may be strongly adsorbed on V=OH (Brönsted acid site) as NH+4(ads); subsequently, NO reacts with this activated NH3 to yield the reaction products N2 and H2O. The present results give support to a dual-site Eley-Rideal-type mechanism involving a Brönsted site. © 1997 John Wiley & Sons, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 71 (1999), S. 994-994 
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Applied Organometallic Chemistry 9 (1995), S. 581-590 
    ISSN: 0268-2605
    Keywords: inorganic tin ; monomethyltin cation ; model studies ; salt marsh ; sediment ; Spartina alterniflora ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: This study describes experiments on sedimentestuarine water slurries originating from a Spartina alterniflora salt marsh. We investigated the fate of tin(IV) or monomethyltin cation (MeSn3+) chlorides after their additon to slurries under anaerobic and aerobic conditions. We did not observe methylation of tin in anaerobic or aerobic slurries with and without added tin(IV). MeSn3+-amended samples occasionally formed small amounts of Me2Sn2+ or Me3Sn+ after extended periods of time, particularly when MeSn3+ remained in solution. The stability of MeSn3+ in slurries demonstrates that the absence of net methylation of tin(IV) is not due to rapid demethylation of MeSn3+ or its further methylation. Inorganic tin concentrations in the aqueous phase of anaerobic slurries spiked with MeSn3+ and unspiked slurries decreased by about 85% in 21 days and remained relatively constant until the end of the 59-day experiments. In similar anaerobic experiments about 25% of the MeSn3+ spike was adsorbed to sediment within 1 h and about 75% was adsorbed within 10 days. The lack of methylation and demethylation reactions in our aerobic and anaerobic slurries, which contrasts with two previous reports, undoubtedly reflects the absence of added nutrients and low concentrations of added tin(IV) in our experiments. We believe that our model experiments more accurately reflect conditions in salt marshes than do previous studies. We conclude that future model studies on methylation of inorganic tin should include. S. alterniflora because it is so prominent in observations of methyltin compounds in the estuary.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...