scholarly journals On the liquid demixing of water + elastin-like polypeptide mixtures: bimodal re-entrant phase behaviour

2021 ◽  
Author(s):  
Tom Lindeboom ◽  
Binwu Zhao ◽  
George Jackson ◽  
Carol Hall ◽  
Amparo Galindo
Keyword(s):  
Transition Temperature ◽  
Liquid Phase ◽  
Conformational Change ◽  
Phase Behaviour ◽  
Cold Denaturation

Water + Elastin-like Polypeptides (ELPs) exhibit a transition temperature below which the chains transform from collapsed to expanded states, reminiscent of cold denaturation. This conformational change coincides with liquid-liquid phase...

scholarly journals The Intramolecular Pressure and the Extension of the Critical Point’s Influence Zone on the Order Parameter

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Jose Luis Rivera ◽  
Homero Nicanor-Guzman ◽  
Roberto Guerra-Gonzalez
Keyword(s):  
Transition Temperature ◽  
Critical Temperature ◽  
Liquid Phase ◽  
Order Parameter ◽  
Bulk Liquid ◽  
Influence Zone ◽  
Molecular Potential ◽  
Liquid Phases ◽  
Dynamics Simulations ◽  
Wide Zone

The critical point affects the coexistence behavior of the vapor-liquid equilibrium densities. The length of the critical influence zone is under debate because for some properties, like shear viscosity, the extension is only a few degrees, while for others, such as the density order parameter, the critical influence zone covers up to hundreds of degrees below the critical temperature. Here we show that, for ethane, the experimental critical influence zone covers a wide zone of tens of degrees (below the critical temperature) down to a transition temperature, at which the apparent critical influence zone vanishes, and the transition temperature can be predicted through a pressure analysis of the coexisting bulk liquid phase, using a simple molecular potential. The liquid phases within the apparent critical influence zone show low densities, making them behave internally like their corresponding vapor phases. Therefore, Molecular Dynamics simulations reveal that the experimentally observed wide extension of the critical influence zone is the result of a vapor-like effect due to low bulk liquid phase densities.

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.

scholarly journals Expansion of Intrinsically Disordered Proteins Increases the Range of Stability of Liquid–Liquid Phase Separation

Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4705
Author(s):  
Adiran Garaizar ◽  
Ignacio Sanchez-Burgos ◽  
Rosana Collepardo-Guevara ◽  
Jorge R. Espinosa
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Protein Interactions ◽  
Conformational Dynamics ◽  
Liquid Phase Separation ◽  
Phase Behaviour ◽  
Coarse Grained ◽  
Protein Protein Interactions ◽  
Intrinsically Disordered ◽  
Liquid Liquid Phase Separation

Proteins containing intrinsically disordered regions (IDRs) are ubiquitous within biomolecular condensates, which are liquid-like compartments within cells formed through liquid–liquid phase separation (LLPS). The sequence of amino acids of a protein encodes its phase behaviour, not only by establishing the patterning and chemical nature (e.g., hydrophobic, polar, charged) of the various binding sites that facilitate multivalent interactions, but also by dictating the protein conformational dynamics. Besides behaving as random coils, IDRs can exhibit a wide-range of structural behaviours, including conformational switching, where they transition between alternate conformational ensembles. Using Molecular Dynamics simulations of a minimal coarse-grained model for IDRs, we show that the role of protein conformation has a non-trivial effect in the liquid–liquid phase behaviour of IDRs. When an IDR transitions to a conformational ensemble enriched in disordered extended states, LLPS is enhanced. In contrast, IDRs that switch to ensembles that preferentially sample more compact and structured states show inhibited LLPS. This occurs because extended and disordered protein conformations facilitate LLPS-stabilising multivalent protein–protein interactions by reducing steric hindrance; thereby, such conformations maximize the molecular connectivity of the condensed liquid network. Extended protein configurations promote phase separation regardless of whether LLPS is driven by homotypic and/or heterotypic protein–protein interactions. This study sheds light on the link between the dynamic conformational plasticity of IDRs and their liquid–liquid phase behaviour.

Liquid-phase behaviour of normal spectral emissivity at 684.5 nm of some selected metals

2002 ◽  
Vol 34 (6) ◽  
pp. 669-679 ◽  
Author(s):  
Claus Cagran ◽  
Christian Brunner ◽  
Achim Seifter ◽  
Gernot Pottlacher
Keyword(s):  
Liquid Phase ◽  
Spectral Emissivity ◽  
Phase Behaviour ◽  
Normal Spectral Emissivity

Influence of Pressure on the Melting Temperature in the Contact of Expanded Nanofilms and Nanoparticles Used in Electronics

2020 ◽  
Vol 28 ◽  
pp. 112-116
Author(s):  
Anatoliy Amishevich Akhkubekov ◽  
Svetlana Nanievna Akhkubekova ◽  
Olga Gudiyeva ◽  
Yuriy Kasumov ◽  
Victor Sozaev
Keyword(s):  
Phase Transition ◽  
Transition Temperature ◽  
Liquid Phase ◽  
Melting Temperature ◽  
Phase Transition Temperature ◽  
Liquid Phase Transition ◽  
Work Relations ◽  
Effect Of Pressure ◽  
External Forces

In this work, relations have been obtained that allow one to estimate the effect of pressure on the temperature of the liquid phase transition between different nanofilms and nanoparticles. It is shown that the external forces lead to a rise in phase transition temperature which should be considered during the contact-reactive soldering in electronics.

Liquid phase behaviour in nonstoichiometric calcium-doped lanthanum chromites

1996 ◽  
Vol 31 (1) ◽  
pp. 157-163 ◽  
Author(s):  
J. D. Carter ◽  
M. M. Nasrallah ◽  
H. U. Anderson
Keyword(s):  
Liquid Phase ◽  
Phase Behaviour ◽  
Calcium Doped ◽  
Lanthanum Chromites
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