Muscle contraction as a polymer-gel phase transition

1999 ◽  
Author(s):  
Gerald H. Pollack
Keyword(s):  
Phase Transition ◽  
Muscle Contraction ◽  
Polymer Gel ◽  
Gel Phase

Polymer-Gel Phase-Transition as the Mechanism of Muscle Contraction

1999 ◽  
Vol 600 ◽  
Author(s):  
Gerald H. Pollack
Keyword(s):  
Phase Transition ◽  
Optimal Design ◽  
Muscle Contraction ◽  
Design Principles ◽  
Maximum Strength ◽  
Artificial Muscles ◽  
Polymer Gel ◽  
Contraction Mechanism ◽  
Gel Phase ◽  
Cross Bridges

AbstractThe thesis offered here is that the muscle-contraction mechanism is similar to the mechanism of contraction in many artificial muscles. Artificial muscles typically contract by a phasetransition. Muscle is thought to contract by a sliding-filament mechanism in which one set of filaments is driven past another by the action of cyclically rotating cross-bridges—much like the mechanism of rowing. However, the evidence is equally consistent with a mechanism in which the filaments themselves contract, much like the condensation of polymers during a phasetransition. Muscle contains three principal polymer types organized neatly within a framework. All three can shorten. The contributions of each filament may be designed to confer maximum strength, speed and versatility on this biological machine. The principles of natural contraction may be useful in establishing optimal design principles for artificial muscles.

Polymer Gel Phase Transition: The Molecular Mechanism of Product Release in Mucin Secretion?

1992 ◽  
pp. 671-681 ◽  
Author(s):  
Pedro Verdugo ◽  
Ingrith Deyrup-Olsen ◽  
Arthur W. Martin ◽  
Daniel L. Luchtel
Keyword(s):  
Phase Transition ◽  
Molecular Mechanism ◽  
Polymer Gel ◽  
Mucin Secretion ◽  
Product Release ◽  
Gel Phase

Electrically induced gel-to-gel phase-transition in neurons

2006 ◽  
Vol 30 (2) ◽  
pp. 175-182 ◽  
Author(s):  
R KELLERMAYER ◽  
A ZSOMBOK ◽  
T AUER ◽  
F GALLYAS
Keyword(s):  
Phase Transition ◽  
Gel Phase

scholarly journals Variation of thermal conductivity of DPPC lipid bilayer membranes around the phase transition temperature

2017 ◽  
Vol 14 (130) ◽  
pp. 20170127 ◽  
Author(s):  
Sina Youssefian ◽  
Nima Rahbar ◽  
Christopher R. Lambert ◽  
Steven Van Dessel
Keyword(s):  
Phase Transition ◽  
Thermal Conductivity ◽  
Thermal Properties ◽  
Transition Temperature ◽  
Lipid Bilayer ◽  
Lipid Bilayers ◽  
Phase Transition Temperature ◽  
Temperature Gradients ◽  
Phase Behaviour ◽  
Gel Phase

Given their amphiphilic nature and chemical structure, phospholipids exhibit a strong thermotropic and lyotropic phase behaviour in an aqueous environment. Around the phase transition temperature, phospholipids transform from a gel-like state to a fluid crystalline structure. In this transition, many key characteristics of the lipid bilayers such as structure and thermal properties alter. In this study, we employed atomistic simulation techniques to study the structure and underlying mechanisms of heat transfer in dipalmitoylphosphatidylcholine (DPPC) lipid bilayers around the fluid–gel phase transformation. To investigate this phenomenon, we performed non-equilibrium molecular dynamics simulations for a range of different temperature gradients. The results show that the thermal properties of the DPPC bilayer are highly dependent on the temperature gradient. Higher temperature gradients cause an increase in the thermal conductivity of the DPPC lipid bilayer. We also found that the thermal conductivity of DPPC is lowest at the transition temperature whereby one lipid leaflet is in the gel phase and the other is in the liquid crystalline phase. This is essentially related to a growth in thermal resistance between the two leaflets of lipid at the transition temperature. These results provide significant new insights into developing new thermal insulation for engineering applications.

Sol-gel phase transition of brucine-appended porphyrin gelator: a study by vibrational circular dichroism spectroscopy

2002 ◽  
Vol 13 (24) ◽  
pp. 2661-2666 ◽  
Author(s):  
Vladimı́r Setnička ◽  
Marie Urbanová ◽  
Statis Pataridis ◽  
Vladimı́r Král ◽  
Karel Volka
Keyword(s):  
Phase Transition ◽  
Circular Dichroism ◽  
Sol Gel ◽  
Circular Dichroism Spectroscopy ◽  
Vibrational Circular Dichroism ◽  
Gel Phase ◽  
Circular Dichroïsm
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