Library

X
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
    Glucose-induced period-doubling cascade in the electrical activity of pancreatic β-cells (1999)
    Springer
    Journal of mathematical biology 38 (1999), S. 21-78 
    Details
    ISSN: 1432-1416
    Keywords: Key words: Bursting-spiking oscillations ; Continuous spiking oscillations ; Kneading sequence ; Period-doubling cascade ; Turning point ; Junction point ; Junction-fold point ; Slow manifold ; Stable and unstable foliations ; Poincaré map ; Asymptotic expansion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Mathematics
    Notes: Abstract  In the presence of stimulatory concentrations of glucose, the membrane potential of pancreatic β-cells may experience a transition from periods of rapid spike-like oscillations alternating with a pseudo-steady state to spike-only oscillations. Insulin secretion from β-cells closely correlates the periods of spike-like oscillations. The purpose of this paper is to study the mathematical structure which underlines this transitional stage in a pancreatic β-cell model. It is demonstrated that the transition can be chaotic but becomes more and more regular with increase in glucose. In particular, the system undergoes a reversed period-doubling cascade leading to the spike-only oscillations as the glucose concentration crosses a threshold. The transition interval in glucose concentration is estimated to be extremely small in terms of the rate of change for the calcium dynamics in the β-cells. The methods are based on the theory of unimodal maps and the geometric and asymptotic theories of singular perturbations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002850050141
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Conjugation for polynomial mappings (1995)
    Springer
    Zeitschrift für angewandte Mathematik und Physik 46 (1995), S. 872-882 
    Details
    ISSN: 1420-9039
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics , Physics
    Notes: Abstract We consider Keller's functions, namely polynomial functionsf:C n →C n with detf(x)=1 at allx εC n. Keller conjectured that they are all bijective and have polynomial inverses. The problem is still open. Without loss of generality assumef(0)=0 andf'(0)=I. We study the existence of certain mappingsh λ, λ 〉 1, defined by power series in a ball with center at the origin, such thath′λ(0)=I andh λ(λf(x))=λh λ(x). So eachh λ conjugates λf to its linear part λI in a ball where it is injective. We conjecture that for Keller's functionsf of the homogeneous formf(x)=x +g(x),g(sx)=s dg(x),g′(x)n=0,xεC n,sεC the conjugationh λ for λf is anentire function.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00917874
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    A Practical Synthesis of 3-Methoxyflavones (1997)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1997 (1997), S. 2169-2175 
    Details
    ISSN: 0947-3440
    Keywords: Baker-Venkataraman rearrangement ; 3-Methoxyflavones ; Phase-transfer catalysis ; Catalytic transfer hydrogenation ; Transesterifications ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Some 3-methoxyflavones were known to possess antipicornavirus properties. In order to study the structure-activity relationship, attempts to prepare 3-methoxyflavone by literature methods were unsuccessful. We have modified the Baker-Venkataraman rearrangement, using a solid base and a phase-transfer catalyst. After searching optimal reaction conditions and a study of the intermediate formed in a model reaction, good yields were obtained for the 3-methoxyflavones 7, 21-32. Further some of the corresponding 7-O-n-butyl derivatives 4, 33-37 could be isolated as side products.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.199719971020
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    A Practical Synthesis of 3-Methoxyflavones (1998)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1998 (1998), S. 1243-1243 
    Details
    ISSN: 1434-193X
    Keywords: Correction ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Correction
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 5
    Electronic Resource
    Electronic Resource
    Synthesis of 7-Vinylflavone and 7-Aminoflavone by Palladium-Catalyzed Coupling Reactions (1999)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1999 (1999), S. 2683-2688 
    Details
    ISSN: 1434-193X
    Keywords: Flavone ; Palladium ; Cross coupling ; Triflate ; Aminations ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Palladium-catalyzed cross-coupling reactions of flavone triflates 2a-c, 4a with tetravinyltin give the corresponding vinylflavones 5a-d, whereas reactions with benzophenone imine, followed by cleavage, afford the corresponding aminoflavone.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...