Nonlinear Metabolic Dynamics of the Pancreas and Liver

1973 ◽  
Vol 95 (3) ◽  
pp. 296-300 ◽  
Author(s):  
R. N. Bergman ◽  
R. J. Bucolo
Keyword(s):  
Insulin Secretion ◽  
Amino Acid ◽  
Dynamic Response ◽  
Dynamic Testing ◽  
Nonlinear Behavior ◽  
Time Dependent ◽  
Metabolic System ◽  
Metabolic Functions ◽  
Organ Level ◽  
Nonlinear Static

Organ level dynamic testing of the metabolic functions of the pancreas and liver have revealed some striking nonlinearities. Glucose provokes a biphasic response in insulin secretion, with dynamic asymmetry and time dependent gain. Amino acid stimulated insulin secretion dynamics contrasted with the dynamic response to glucose in that the gain was not time dependent, and the final phase of insulin secretion did not occur. Also, the magnitude of the amino acid response was very sensitive to the glucose level. A nonlinear model is proposed which accounts for the observed insulin secretory dynamics. The dynamic response of the net glucose balance of the liver in response to glucose was also studied and it was found that, in contrast to the pancreas, the liver can be represented simply by a first order process with a nonlinear static gain curve. These dynamic studies should help explain the nonlinear behavior of the metabolic system at the level of the whole animal.

4-Hydroxyisoleucine: a novel amino acid potentiator of insulin secretion

Diabetes ◽  
1998 ◽  
Vol 47 (2) ◽  
pp. 206-210 ◽  
Author(s):  
Y. Sauvaire ◽  
P. Petit ◽  
C. Broca ◽  
M. Manteghetti ◽  
Y. Baissac ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Amino Acid

scholarly journals Author Correction: CD44 variant inhibits insulin secretion in pancreatic β cells by attenuating LAT1-mediated amino acid uptake

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Nana Kobayashi ◽  
Shogo Okazaki ◽  
Oltea Sampetrean ◽  
Junichiro Irie ◽  
Hiroshi Itoh ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Amino Acid ◽  
Amino Acid Uptake ◽  
Acid Uptake ◽  
Β Cells ◽  
Pancreatic Β Cells ◽  
Cd44 Variant

Geometrically nonlinear static and dynamic analysis of CNT reinforced laminated composite plates: A finite element study

2021 ◽  
pp. 095440622110089
Author(s):  
Balakrishna Adhikari ◽  
BN Singh
Keyword(s):  
Finite Element ◽  
Free Vibration ◽  
Dynamic Response ◽  
Integration Scheme ◽  
Static And Dynamic Analysis ◽  
Finite Element Study ◽  
Nonlinear Eigenvalues ◽  
Nonlinear Static ◽  
The Impact ◽  
Element Study

In this paper, a finite element study is conducted using the Green Lagrange strain field based on vonKarman assumptions for the geometric nonlinear static and dynamic response of the laminated functionally graded CNT reinforced (FG-CNTRC) composite plate. The governing equations for determining the nonlinear static and dynamic behavior of the FG-CNTRC plate are derived using the Lagrange equation of motion based on Reddy's higher order theory. Using the direct iteration technique, the nonlinear eigenvalues for analyzing the free vibration response are obtained and the nonlinear dynamic responses of the FG-CNTRC plate are encapsulated based on the nonlinear Newmark integration scheme. The impact of the amplitude of vibration on mode switching phenomena and the consequence of the duration of the pulse on the free vibration regime of the plate are outlined. Also, the effect of time dependent loads is studied on the normal stresses of the plate. Furthermore, the impact on the nonlinear static and dynamic response of the laminated FG-CNTRC plate of various parameters such as span-thickness ratio (b/h ratio), aspect ratio (a/b ratio), different edge constraints, CNT fiber gradation, etc. are also studied.

The roles of amino acid residues at positions 216 and 219 in the structural stability and metabolic functions of rat cytochrome P450 2D1 and 2D2

2008 ◽  
Vol 172 (1) ◽  
pp. 11-21 ◽  
Author(s):  
Shizuo Narimatsu ◽  
Kimio Kiryu ◽  
Rei Yonemoto ◽  
Manabu Yoshino ◽  
Mitsuko Kobatake ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Amino Acid ◽  
Structural Stability ◽  
Amino Acid Residues ◽  
Metabolic Functions

Nonlinear behavior of Helmholtz resonator with a compliant wall for low frequency, broadband noise control

2021 ◽  
pp. 1-29
Author(s):  
Maya Pishvar ◽  
Ryan L Harne
Keyword(s):  
Dynamic Response ◽  
Low Frequency ◽  
Nonlinear Behavior ◽  
Helmholtz Resonator ◽  
Broadband Noise ◽  
Sound Attenuation ◽  
Wall Material ◽  
Modeling Framework ◽  
Compliant Wall ◽  
Broadband Sound

Abstract Low frequency sound attenuation is often pursued using Helmholtz resonators (HRs). The introduction of a compliant wall around the acoustic cavity results in a two-degree-of-freedom (2DOF) system capable of more broadband sound absorption. In this study, we report the amplitude-dependent dynamic response of a compliant walled HR and investigate the effectiveness of wall compliance to improve the absorption of sound in linear and nonlinear regimes. The acoustic-structure interactions between the conventional Helmholtz resonator and the compliant wall result in non-intuitive responses when acted on by nonlinear amplitudes of excitation pressure. This paper formulates and studies a reduced order model to characterize the nonlinear dynamic response of the 2DOF HR with a compliant wall compared to that of a conventional rigid HR. Validated by experimental evidence, the modeling framework facilitates an investigation of strategies to achieve broadband sound attenuation, including by selection of wall material, wall thickness, geometry of the HR, and other parameters readily tuned by system design. The results open up new avenues for the development of efficient acoustic resonators exploiting the deflection of a compliant wall for suppression of extreme noise amplitudes.

Dynamic Behavior of Aircraft Wings Modeled as Doubly-Tapered Composite Thin-Walled Beams

1999 ◽  
Author(s):  
Sungsoo Na ◽  
Liviu Librescu
Keyword(s):  
Composite Materials ◽  
Free Vibration ◽  
Dynamic Response ◽  
Dynamic Behavior ◽  
Transverse Shear ◽  
Dynamical Behavior ◽  
Time Dependent ◽  
Aircraft Wings ◽  
Helicopter Blades ◽  
Thin Walled

Abstract A study of the dynamical behavior of aircraft wings modeled as doubly-tapered thin-walled beams, made from advanced anisotropic composite materials, and incorporating a number of non-classical effects such as transverse shear, and warping inhibition is presented. The supplied numerical results illustrate the effects played by the taper ratio, anisotropy of constituent materials, transverse shear flexibility, and warping inhibition on free vibration and dynamic response to time-dependent external excitations. Although considered for aircraft wings, this analysis and results can be also applied to a large number of structures such as helicopter blades, robotic manipulator arms, space booms, tall cantilever chimneys, etc.

scholarly journals CD44 variant inhibits insulin secretion in pancreatic β cells by attenuating LAT1-mediated amino acid uptake

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Nana Kobayashi ◽  
Shogo Okazaki ◽  
Oltea Sampetrean ◽  
Junichiro Irie ◽  
Hiroshi Itoh ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Amino Acid ◽  
Amino Acid Uptake ◽  
Acid Uptake ◽  
Β Cells ◽  
Pancreatic Β Cells ◽  
Cd44 Variant

Dynamic Response of Sandwich Anisotropic Flat Panels to Explosive Pressure Pulses

2001 ◽  
Author(s):  
Terry Hause ◽  
Liviu Librescu
Keyword(s):  
Dynamic Response ◽  
Detailed Analysis ◽  
Fiber Orientation ◽  
Sandwich Structures ◽  
Sandwich Panels ◽  
Core Layer ◽  
Time Dependent ◽  
Pressure Pulses ◽  
The Face ◽  
Advanced Model

Abstract This paper addresses the problem of the dynamic response in bending of flat sandwich panels exposed to time-dependent external pulses. The study is carried out in the context of an advanced model of sandwich structures that is characterized by anisotropic laminated face sheets and an orthotropic core layer. A detailed analysis of the influence of a large number of parameters associated with the particular type of pressure pulses, panel geometry, fiber orientation in the face sheets and, presence of tensile uni/biaxial edge loads is accomplished, and pertinent conclusions are outlined.

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