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
    Experimental brain research 14 (1971), S. 95-104 
    ISSN: 1432-1106
    Keywords: GABA ; Strio-nigral neurons ; Elongated synaptic vesicles ; Hemitransection ; Bouton-degeneration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Interference with the neuronal connection between the substantia nigra and striatum of rat by hemitransection at the subthalamic level or lesion of left side of striatum by a simple suction method was studied in relation to the concentration of γ-aminobutyric acid (GABA) in both regions. Time interval studies, at two, six, and twelve days after hemitransection, showed that the GABA concentration in substantia nigra had markedly decreased, whereas only a slight change was shown on the striatum of the operated side. Destruction of the striatum by suction caused a significant fall of the GABA content in the ipsilateral side of substantia nigra. However, destruction of the frontal cortex alone did not cause any marked change in the GABA content of the substantia nigra. In addition, electron microscopic studies disclosed that within the synaptic organization of the substantia nigra approximately 20 % of the boutons contained elongated synaptic vesicles, and that, following coagulation of the striatum, some large axosomatic terminals containing elongated synaptic vesicles also underwent degeneration.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    European archives of psychiatry and clinical neuroscience 232 (1982), S. 33-38 
    ISSN: 1433-8491
    Keywords: Phosphatidylcholine ; Glutamate ; GABA ; Brain ; CSF ; Friedreich's ataxia ; Phosphatidylcholin ; Glutamat ; GABA ; ZNS ; Liquor cerebrospinalis ; Friedreichsche Ataxie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Um zu untersuchen, ob die Gabe von Phosphatidylcholin, die den zentralnervösen Azetylcholingehalt erhöht, einen Einfluß auf die Neurotransmitter Glutamat und GABA hat, wurde 17 von 32 Ratten über 14 Tage 1,5g/kg Lethicon® pro die peroral gegeben. Die fluorometrische Messung der Konzentrationen von Glutamat und GABA in frontalem Cortex, Striatum, Nigra, Kleinhirnrinde sowie von Glutamat im Liquor cerebrospinalis ließ keine signifikanten Unterschiede gegenüber Kontrolltieren erkennen. Nach zweiwöchiger Gabe von Phosphatidylcholin konnte keine zentralnervöse Interaktion des cholinergen Systems mit den Neurotransmittern Glutamat und GABA nachgewiesen werden.
    Notes: Summary Phosphatidylcholine increases CNS concentrations of acetylcholine. In rats we investigated whether or not phosphatidylcholine also influences the neurotransmitters glutamate and GABA. In 17 rats 1.5g/kg Lethicon perorally was administered daily for 2 weeks, 15 rats served as controls. In tissue from frontal cortex, striatum, substantia nigra, cerebellar cortex no significant differences between treated and untreated animals were found in glutamate or GABA concentrations. A central nervous interaction between the cholinergic system and the neurotransmitters glutamate and GABA, therefore, could not be demonstrated after 2 weeks of phosphatidylcholine intake.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    European archives of psychiatry and clinical neuroscience 232 (1982), S. 183-189 
    ISSN: 1433-8491
    Keywords: Ethanol ; Barbiturate ; Cortex ; GABA ; Glutamate ; Hippocampus ; Nigra ; Striatum ; Aethanol ; Barbiturat ; Cortex ; GABA ; Glutamat ; Hippocampus ; Nigra ; Striatum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung In zwei Versuchsserien wurde der Einfluß von chronischer Aethanolgabe (5 g/kg täglich) über 2 bzw. 4 Wochen auf die Neurotransmitter Glutamat und GABA bei Ratten untersucht. Dabei fand sich ein durch Barbiturat maskierter Anstieg der GABA-Konzentration in Striatum, Hippocampus und Substantia nigra, 8 bzw. 12 Stunden nach der letzten Aethanolgabe. Für Glutamat konnte ebenfalls ein Anstieg in den untersuchten Hirnregionen gefunden werden, der mit den für Dopamin bekannten Veränderungen unter Aethanol vereinbar ist. Die Bedeutung für die Pathogenese hirnorganischer Anfälle und psychotischer Symptome nach chronischem Alkoholmißbrauch wird diskutiert.
    Notes: Summary The effect of chronic ethanol administration, 5 g/kg per day for 2 or 4 weeks, on the neurotransmitters glutamate and GABA was investigated in rats. An increase in GABA was found in the striatum, hippocampus, and substantia nigra, 8 or 12 h after the last ingestion of ethanol, this being masked by injection of barbiturate. In addition an increase of glutamate has been found in the examined brain areas. This is consistent with the known effect of ethanol on brain Dopa metabolism and release. Finally, the relevance of the results for the pathogenesis of withdrawal seizures and delirious states is discussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 7 (1987), S. 1235-1259 
    ISSN: 0271-2091
    Keywords: Fluid Mechanics ; CFD ; Finite Element ; Accuracy/Convergence ; Stability ; PNS/TLNS ; Turbulent ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: This paper develops and analyses individual construction aspects of an efficient and accurate finite element algorithm for prediction of viscous and turbulent flow fields of impact in aerodynamics. The theoretical construction employs a Taylor weak statement (TWS) for coincident embedding of stability mechanisms within a classic Galerkin finite element formulation of semi-discrete approximation error orthogonalization. A wide variety of the stabilizing mechanisms of independently derived CFD algorithms are contained within the TWS theory. An implicit construction that meets the requirement of efficient convergence to steady state is developed. The theoretical asymptotic error estimates of the TWS finite element algorithm for supersonic and viscous boundary layer flows are verified. Application to a three-dimensional turbulent flow is cited.
    Additional Material: 8 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
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 7 (1987), S. 489-520 
    ISSN: 0271-2091
    Keywords: CFD Algorithm ; Weak Statement ; Hyperbolic ; Parabolic ; Dissipation ; Dispersion ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Finite element analysis, applied to computational fluid dynamics (CFD) problem classes, presents a formal procedure for establishing the ingredients of a discrete approximation numerical solution algorithm. A classical Galerkin weak-statement formulation, formed on a Taylor series extension of the conservation law system, is developed herein that embeds a set of parameters eligible for constraint according to specification of suitable norms. The derived family of Taylor weak statements is shown to contain, as special cases, over one dozen independently derived CFD algorithms published over the past several decades for the high speed flow problem class. A theoretical analysis is completed that facilitates direct qualitative comparisons. Numerical results for definitive linear and non-linear test problems permit direct quantitative performance comparisons.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 39 (1996), S. 1903-1914 
    ISSN: 0029-5981
    Keywords: axisymmetric shell ; mixed finite element ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: An efficient, perhaps simplest, three-noded mixed finite element is proposed for axisymmetric shell analysis. The key feature in the present formulation is to start with a better variational principle in which the independent unknowns are only the quantities that can be prescribed at the shell edges. If the consistency for field approximations is satisfied, no other numerical consideration is necessary in the present element. Several examples confirm the satisfactory numerical behaviour of the present mixed element.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 13 (1997), S. 565-572 
    ISSN: 1069-8299
    Keywords: mixed harmonic element ; shells of revolution ; consistent stress parameters ; Engineering ; Numerical Methods and Modeling
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A simple and efficient three-noded mixed harmonic axisymmetric element for shells of revolution under non-symmetric loading is developed. The present element considering shear strain is based on a modified mixed variational principle in which the independent unknowns are only the quantities prescribable at the shell edges. The non-symmetric variations of the displacements and stress resultants in the circumferential direction are decomposed in terms of Fourier series. The stress resultants are eliminated on the element level so that the standard stiffness equations are obtained. The importance of consistent stress parameters is addressed and the efficiency of the present consistent mixed element is shown. © 1997 John Wiley & Sons, Ltd.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 1703-1720 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: An assumed strain finite element formulation with a stabilization matrix is developed for analysis of geometrically non-linear problems of isotropic and laminated composite shells. The present formulation utilizes the degenerate solid shell concept and assumes an independent strain as well as displacement. The assumed independent strain field is divided into a lower order part and a higher order part. Subsequently, the lower order part is set equal to the displacement-dependent strain evaluated at the lower order integration points and the remaining higher order part leads to a stabilization matrix. The strains and the determinant of the Jacobian matrix are assumed to vary linearly in the thickness direction. This assumption allows analytical integration through thickness, independent of the number of plies. A nine-node element with a judiciously chosen set of higher order assumed strain field is developed. Numerical tests involving isotropic and composite shells undergoing large deflections demonstrate the validity of the present formulation.
    Additional Material: 13 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...