Energy landscapes for cooperative processes: nearly ideal glass transitions, liquid–liquid transitions and folding transitions

2004 ◽  
Vol 363 (1827) ◽  
pp. 415-432 ◽  
Author(s):  
C. Austen Angell
Keyword(s):  
Phase Transitions ◽  
Liquid Phase ◽  
Point Defects ◽  
Laboratory Experiments ◽  
Constant Pressure ◽  
Energy Landscape ◽  
Experimental Methods ◽  
Glass Transitions ◽  
Energy Landscapes ◽  
Cooperative Processes

We describe basic phenomenology in the physics of supercooling liquids at constant volume (most simulations), and at constant pressure (most laboratory experiments) before focusing attention on the exceptional cases that exhibit liquid–liquid phase transitions on constant–pressure cooling. We give evidence for point defects in glasses and liquids near T g . Models based on defects predict transitions with density gaps in constant–pressure systems. We describe the energy landscape representation of such systems. Water, in these terms, is post–critical, and its nearly ideal glass formation can be related to nucleation–free protein ‘funnel–folding’. For nucleated folding of proteins, a pseudo–gap should be present. Experimental methods of distinguishing between alternative folding scenarios are described.

Phenomenological hysteresis model for vapor-liquid phase transitions

2008 ◽  
Vol 3 (1) ◽  
pp. 5-28 ◽  
Author(s):  
Ildiko Jancskar ◽  
Amalia Ivanyi
Keyword(s):  
Phase Transitions ◽  
Liquid Phase ◽  
Hysteresis Model ◽  
Vapor Liquid

scholarly journals Crystal–liquid phase transitions in three-dimensional complex plasma under microgravity conditions

2018 ◽  
Vol 946 ◽  
pp. 012144 ◽  
Author(s):  
V N Naumkin ◽  
A M Lipaev ◽  
V I Molotkov ◽  
D I Zhukhovitskii ◽  
A D Usachev ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Liquid Phase ◽  
Three Dimensional ◽  
Complex Plasma ◽  
Microgravity Conditions

scholarly journals Universally bistable shells with nonzero Gaussian curvature for two-way transition waves

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Nikolaos Vasios ◽  
Bolei Deng ◽  
Benjamin Gorissen ◽  
Katia Bertoldi
Keyword(s):  
Gaussian Curvature ◽  
Energy Landscape ◽  
Propagation Distance ◽  
Energy Landscapes ◽  
Bending Energy ◽  
Nonlinear Dynamic Response ◽  
One Dimensional ◽  
Doubly Curved Shells ◽  
Doubly Curved ◽  
The Waves

AbstractMulti-welled energy landscapes arising in shells with nonzero Gaussian curvature typically fade away as their thickness becomes larger because of the increased bending energy required for inversion. Motivated by this limitation, we propose a strategy to realize doubly curved shells that are bistable for any thickness. We then study the nonlinear dynamic response of one-dimensional (1D) arrays of our universally bistable shells when coupled by compressible fluid cavities. We find that the system supports the propagation of bidirectional transition waves whose characteristics can be tuned by varying both geometric parameters as well as the amount of energy supplied to initiate the waves. However, since our bistable shells have equal energy minima, the distance traveled by such waves is limited by dissipation. To overcome this limitation, we identify a strategy to realize thick bistable shells with tunable energy landscape and show that their strategic placement within the 1D array can extend the propagation distance of the supported bidirectional transition waves.

scholarly journals Prion-Like Proteins in Phase Separation and Their Link to Disease

Biomolecules ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1014
Author(s):  
Macy L. Sprunger ◽  
Meredith E. Jackrel
Keyword(s):  
Protein Folding ◽  
Phase Transitions ◽  
Phase Separation ◽  
Liquid Phase ◽  
Protein Misfolding ◽  
Solid Phase ◽  
Liquid Phase Separation ◽  
Therapeutic Approaches ◽  
Important Physiological Process ◽  
Liquid Liquid Phase Separation

Aberrant protein folding underpins many neurodegenerative diseases as well as certain myopathies and cancers. Protein misfolding can be driven by the presence of distinctive prion and prion-like regions within certain proteins. These prion and prion-like regions have also been found to drive liquid-liquid phase separation. Liquid-liquid phase separation is thought to be an important physiological process, but one that is prone to malfunction. Thus, aberrant liquid-to-solid phase transitions may drive protein aggregation and fibrillization, which could give rise to pathological inclusions. Here, we review prions and prion-like proteins, their roles in phase separation and disease, as well as potential therapeutic approaches to counter aberrant phase transitions.

From the bulk to clusters: Solid-liquid phase transitions and precursor effects

1990 ◽  
Vol 24-26 (1) ◽  
pp. 283-342 ◽  
Author(s):  
R. Kofman ◽  
P. Cheyssac ◽  
R. Garrigos
Keyword(s):  
Phase Transitions ◽  
Liquid Phase ◽  
Precursor Effects ◽  
Solid Liquid

Water and its anomalies in perspective: tetrahedral liquids with and without liquid–liquid phase transitions

2000 ◽  
Vol 2 (8) ◽  
pp. 1559-1566 ◽  
Author(s):  
C. A. Angell ◽  
R. D. Bressel ◽  
M. Hemmati ◽  
E. J. Sare ◽  
J. C. Tucker
Keyword(s):  
Phase Transitions ◽  
Liquid Phase

scholarly journals Evolution of weak cooperative interactions for biological specificity

2018 ◽  
Vol 115 (47) ◽  
pp. E11053-E11060 ◽  
Author(s):  
Ang Gao ◽  
Krishna Shrinivas ◽  
Paul Lepeudry ◽  
Hiroshi I. Suzuki ◽  
Phillip A. Sharp ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Liquid Phase ◽  
Evolutionary Model ◽  
Cross Reactivity ◽  
Cellular Functions ◽  
Cooperative Interactions ◽  
Lethal Mutations ◽  
Evolutionary Changes ◽  
Biological Specificity ◽  
Multicellular Organisms

A hallmark of biological systems is that particular functions and outcomes are realized in specific contexts, such as when particular signals are received. One mechanism for mediating specificity is described by Fisher’s “lock and key” metaphor, exemplified by enzymes that bind selectively to a particular substrate via specific finely tuned interactions. Another mechanism, more prevalent in multicellular organisms, relies on multivalent weak cooperative interactions. Its importance has recently been illustrated by the recognition that liquid-liquid phase transitions underlie the formation of membraneless condensates that perform specific cellular functions. Based on computer simulations of an evolutionary model, we report that the latter mechanism likely became evolutionarily prominent when a large number of tasks had to be performed specifically for organisms to function properly. We find that the emergence of weak cooperative interactions for mediating specificity results in organisms that can evolve to accomplish new tasks with fewer, and likely less lethal, mutations. We argue that this makes the system more capable of undergoing evolutionary changes robustly, and thus this mechanism has been repeatedly positively selected in increasingly complex organisms. Specificity mediated by weak cooperative interactions results in some useful cross-reactivity for related tasks, but at the same time increases susceptibility to misregulation that might lead to pathologies.

scholarly journals Viscosity Measurement of Olive Oil under Pressure

2021 ◽  
Vol 6 (5) ◽  
Author(s):  
Pawlicki LT
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Phase Transitions ◽  
Liquid Phase ◽  
Olive Oil ◽  
Measurement Method ◽  
Viscosity Measurement ◽  
Food Preservation ◽  
Characteristic Frequencies ◽  
Viscosity Changes

This article presents changes in the viscosity of olive oil during compression. The test was carried out indirectly by measuring the dependence of the resonance frequency of the piezoelectric immersed in olive oil on pressure. For this purpose, for successive pressures, the resonance curves were read and the values of the characteristic frequencies were determined. Viscosity changes were analysed and related to the compression and crystallization taking place in the tested substance. During this research, a phase transition from the liquid phase to the alpha crystalline phase was detected, during which the resonant frequency of the tested piezoelectric reached a minimum and the viscosity related to this frequency reached a maximum. The measurement method developed in this paper can be used to detect the phase transitions of oils subjected to pressure. This may find application in the oil production and high-pressure food preservation industries for which this knowledge is essential for the safe and trouble-free use of their machines.

scholarly journals Liquid-liquid phase separation and morphology of internally mixed dicarboxylic acids/ammonium sulfate/water particles

2011 ◽  
Vol 11 (10) ◽  
pp. 29141-29194 ◽  
Author(s):  
M. Song ◽  
C. Marcolli ◽  
U. K. Krieger ◽  
A. Zuend ◽  
T. Peter
Keyword(s):  
Phase Transitions ◽  
Phase Separation ◽  
Liquid Phase ◽  
Ammonium Sulfate ◽  
Particle Surface ◽  
Dicarboxylic Acids ◽  
Liquid Phase Separation ◽  
Model Systems ◽  
Second Phase ◽  
Liquid Liquid Phase Separation

Abstract. Knowledge of the physical state and morphology of internally mixed organic/inorganic aerosol particles is still largely uncertain. To obtain more detailed information on liquid-liquid phase separation (LLPS) and morphology of the particles, we investigated complex mixtures of atmospherically relevant dicarboxylic acids containing 5–7 carbon atoms (C5, C6 and C7) having oxygen-to-carbon atomic ratios (O:C) of 0.80, 0.67, and 0.57, respectively, mixed with ammonium sulfate (AS). With micrometer-sized particles of C5/AS/H2O, C6/AS/H2O and C7/AS/H2O as model systems deposited on a hydrophobically coated substrate, laboratory experiments were conducted for various organic-to-inorganic dry mass ratios (OIR) using optical microscopy and Raman spectroscopy. When exposed to cycles of relative humidity (RH), each system showed significantly different phase transitions. While the C5/AS/H2O particles showed no LLPS with OIR = 2:1, 1:1 and 1:4 down to 20% RH, the C6/AS/H2O and C7/AS/H2O particles exhibit LLPS upon drying at RH 50% to 85% and ~90%, respectively, via spinodal decomposition, growth of a second phase from the particle surface or nucleation-and-growth mechanisms depending on the OIR. This suggests that LLPS commonly occurs within the range of O:C<0.7 in tropospheric organic-inorganic aerosols. To support the comparison and interpretation of the experimentally observed phase transitions, thermodynamic equilibrium calculations were performed with the AIOMFAC model. For the C7/AS/H2O and C6/AS/H2O systems, the calculated phase diagrams agree well with the observations while for the C5/AS/H2O system LLPS is predicted by the model at RH below 60% and higher AS concentration, but was not observed in the experiments. Both core-shell structures and partially engulfed structures were observed for the investigated particles, suggesting that such morphologies might also exist in tropospheric aerosols.

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