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
    ISSN: 1432-1440
    Keywords: Cardiotoxicity of contrast media ; Angiocardiography ; Calcium addition to ionic contrast media ; Metrizamide ; Kardiale Nebenwirkungen von Kontrastmitteln ; Kalziumzusatz zu ionischen Kontrastmitteln ; Metrizamid ; Angiocardiographie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung In einer klinischen Vergleichsstudie wurde überprüft, inwieweit die kardialen Nebenwirkungen der Angiokardiographie durch Zusatz von Kalzium zum üblicherweise verwandten Diatrizoat (Urografin 76%) und Verwendung von nichtionischem Metrizamid (Amipaque) reduziert werden können. Fünfzehn Patienten wurden hierzu unter randomisierten Bedingungen mit Diatrizoat, mit und ohne Kalziumzusatz (11,3 mmol/l), und Metrizamid (320 mg/ml Jod), in jeweils einer Untersuchung, links und rechts koronarographiert und mit Diatrizoat sowie Metrizamid zweimalig lävographiert. Im Rahmen der selektiven, links- und rechtskoronaren Injektionen bewirkt der Kalzium-Zusatz bereits eine deutliche Abschwächung der bekannten kardiodepressiven Wirkung von Diatrizoat: Der linksventrikuläre Spitzendruck fällt statt im Mittel um 30±11% (einfache Standardabweichung) um lediglich 23±12% gegenüber dem Ausgangswert ab, dP/dtmax statt um 31±15% um lediglich 20±10%. Im paarweisen Vergleich der Injektionsreaktionen mit und ohne zugesetztem Kalzium, zeigt sich der Unterschied als schwach signifikant (p〈0,05). Bei Verwendung des nichtionischen Metrizamids zeigen sich die kardiodepressiven Nebenwirkungen in noch geringerer Ausprägung. Die Druckminderung im linken Ventrikel beträgt hier nur 13±10%, die Kontraktilität fällt lediglich um 7±7% ab (bezogen auf einen mittleren Ausgangswert). Der Unterschied zu den Reaktionen unter Diatrizoat allein ist mitp〈0,001 hochsignifikant. Die unter Diatrizoat zum Teil ausgeprägte Frequenzverlangsamung zeigt sich unverändert auch bei Zusatz von Kalzium. Bei Verwendung von Metrizamid ist sie nur angedeutet. Bei der linksventrikulären Injektion zeigen sich deutliche Unterschiede in der Phase peripherer Vasodilatation. Während es hier unter Diatrizoat zu einem deutlichen Druckabfall kommt, ist dieser unter Metrizamid, dem Kontrastmittel mit wesentlich niedrigerer Osmolarität, kaum nachzuweisen (p〈0,001). Da unter Metrizamid die unerwünschten, kardialen Nebenwirkungen, wie Senkung des Perfusionsdrucks, gering sind, erweist es sich als besonders geeignet für die Untersuchung von Risikopatienten. Hinsichtlich seiner geringen Nebenwirkungsrate übertrifft es auch Diatrizoat in Kombination mit Kalzium.
    Notes: Summary Cardiodepressive side effects of angiocardiography can be reduced by using non-ionic metrizamide (Amipaque) or adding calcium to diatrizoate (Urografin 76%). In 15 patients with coronary artery disease undergoing heart catheterization, we compared cardiac side effects of coronary angiography and left ventricular angiography using metrizamide and diatrizoate with and without additional calcium (11,3 mmol/l) as contrast media under randomized conditions. In selective intracoronary injection with diatrizoate alone, peak left ventricular pressure and contractility (dP/dtmax) showed a fall of 30±11% and 31±15% (n=33 injections). Using diatrizoate with added calcium (11,3 mmol/l), the fall was only 23±12% and 20±10% respectively (n=31 injections). With metrizamide (n=32 injections) cardiac side effects are even less and the decrease in pressure and contractility only 13±10% and 7±7% respectively, which its highly significant (p〈0,001) compared with the effect of diatrizoate. The heartrate slowing, not essentially altered by calcium addition, was minimal using non-ionic metrizamide. In left ventricular angiography, the pressure fall in the late phase after injection of diatrizoate, caused by decreased peripheral vascular resistance (vasodilation), was lacking when injecting metrizamide (p〈0,001). Metrizamide has even less cardiodepressive side effects than diatrizoate with additional calcium when used in angiocardiography and seems to be suitable particularly for the evaluation of high risk patients.
    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
    Numerische Mathematik 55 (1989), S. 545-563 
    ISSN: 0945-3245
    Keywords: AMS(MOS): 65L05 ; CR: G1.7
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Summary Two Rosenbrock-Wanner type methods for the numerical treatment of differential-algebraic equations are presented. Both methods possess a stepsize control and an index-1 monitor. The first method DAE34 is of order (3)4 and uses a full semi-implicit Rosenbrock-Wanner scheme. The second method RKF4DA is derived from the Runge-Kutta-Fehlberg 4(5)-pair, where a semi-implicit Rosenbrock-Wanner method is embedded, in order to solve the nonlinear equations. The performance of both methods is discussed in artificial test problems and in technical applications.
    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
    Numerische Mathematik 35 (1980), S. 81-93 
    ISSN: 0945-3245
    Keywords: AMS(MOS): 65D05 ; 65D10 ; CR:5.13
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Summary Procedures for the calculation of the exponential spline (spline under tension) are presented in this paper. The procedureexsplcoeff calculates the second derivatives of the exponential spline. Using the second derivatives the exponential spline can be evaluated in a stable and efficient manner by the procedureexspl. The limiting cases of the exponential spline, the cubic spline and the linear spline are included. A proceduregenerator is proposed, which computes appropriate tension parameters. The performance of the algorithm is discussed for several examples.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Numerische Mathematik 64 (1993), S. 521-539 
    ISSN: 0945-3245
    Keywords: 65L05 ; 70-08
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Summary The numerical analysis of multibody system dynamics is based on the equations of motion as differential-algebraic systems. A thorough analysis of the linearized equations and their solution theory leads to an equivalent system of ordinary differential equations which gives deeper insight into the derivation of integration schemes and into the stabilization approaches. The main tool is the Drazin inverse, a generalized matrix inverse, which preserves the eigenvalues. The results are illustrated by a realistic truck model. Finally, the approach is extended to the nonlinear index 2 formulation.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 0945-3245
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Summary A modification of the well-known continuation (or homotopy) method for actual computation is worked out. Compared with the classical method, the modification seems to be a more reliable device for supplying useful initial data for shooting techniques. It is shown that computing time may be significantly reduced in the numerical solution of sensitive realistic two-point boundary value problems.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 0945-3245
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Summary The numerical solution of two-point boundary value problems and problems of optimal control by shooting techniques requires integration routines. By solving 15 real-life problems four well-known intergrators are compared relative to reliability, fastness and precision. Hints are given, which routines could be used for a problem.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Numerische Mathematik 31 (1978), S. 359-375 
    ISSN: 0945-3245
    Keywords: AMS (MOS): 65L10 ; CR: 5.17
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Summary For the numerical solution of two-point boundary value problems a shooting algorithm based on a Taylor series method is developed. Series coefficients are generated automatically by recurrence formulas. The performance of the algorithm is demonstrated by solving six problems arising in nonlinear shell theory, chemistry and superconductivity.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Computing 16 (1976), S. 61-67 
    ISSN: 1436-5057
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Description / Table of Contents: Zusammenfassung Es wird eine handliche Methode zur Lösung singulärer Randwertprobleme gewöhnlicher Differentialgleichungen behandelt. Taylorreihenentwicklungen des Systems in einem kleinen Intervall blenden die Singularität aus, so daß die Aufgabe mit der Mehrzielmethode gelöst werden kann. Die Zuverlässigkeit dieses Verfahrens wird bei der Lösung der Ginzburg-Landau-Gleichungen der Supraleitung nachgewiesen.
    Notes: Abstract A useful method for the numerical solution of singular two-point boundary value problems by multiple shooting techniques is treated. In a small interval Taylor series expansions are used in orderto kill the numerical singularity. The reliability of the method is demonstrated by solving the Ginzburg-Landau equations arising in the theory of superconductivity.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1619-7089
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Left ventricular ejection fractions (EF) were determined in 37 patients by biplane cineventriculography (Angio) and by four modifications of the gated equilibrium blood pool (GBP) method: 1. Region of interest (ROI) in enddiastole (ED), correction by external background 2. ROI in ED, correction by internal background between ED and endsystole (ES) 3. ROI in ED (maximum) and ES (minimum); no background correction 4. ROI in ES, correction by background between ED and ES. EFGBP were determined after injection of 20 mCi 99mTc human albumin (Anger-camera, all-purpose collimator, 16 ECG-segments, 64 x 64 matrix with 1.5 zoom). EF by biplane angiography (EFangio) was calculated by the formula of Dodge. The following correlation between angiographically and scintigraphically determined EF's were found: $$\begin{gathered} EF_{GBP 1} = 0.504 EF_{angio} + 8.08, \hfill \\ EF_{GBP 2} = 0.847 EF_{angio} + 10.0, \hfill \\ EF_{GBP 3} = 0.911 EF_{angio} + 3.75, \hfill \\ EF_{GBP 4} = 0.648 EF_{angio} --- 3.51 \hfill \\\end{gathered}$$ Intraobserver variability of GBP method 2 and 3 was±5%. EFs determined by GBP methods 2 and 3 are as accurate as the EFs determined by cineventriculography.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Archive of applied mechanics 48 (1979), S. 197-203 
    ISSN: 1432-0681
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Übersicht Es werden die Stabilitätskurven dünner elastischer Kugelkappen und Halbkugeln für den eingespannten und den einfach gestützten Rand berechnet. Die Formulierung des Problems erfolgt im Rahmen der Reissner-Tehorie, die die Schalenprobleme auf die Lösung von Randwertaufgaben gewöhnlicher Differentialgleichungen zurückführt. Mit Hilfe eines Schießverfahrens werden die nichtlinearen Randwertprobleme gelöst.
    Notes: Summary Stability curves for thin elastic spherical shell segments and hemispheres are computed for the clamped and the simply supported edge condition. The formulation of the shell problem due to Reissner leads to two-point value boundary problems. These nonlinear boundary value problems are solved using a shooting algorithm.
    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...