Exploring the influence of natural cosolvents on the free energy and conformational landscape of filamentous actin and microtubules

2018 ◽  
Vol 20 (45) ◽  
pp. 28400-28411 ◽  
Author(s):  
Paul Hendrik Schummel ◽  
Michel W. Jaworek ◽  
Christopher Rosin ◽  
Jessica Högg ◽  
Roland Winter
Keyword(s):  
Free Energy ◽  
Significant Influence ◽  
Filamentous Actin ◽  
Conformational Landscape ◽  
Temperature And Pressure

Natural osmolytes have a significant influence on the temperature- and pressure-dependent stability of filamentous actin and microtubules.

Exploring the Free Energy and Conformational Landscape of tRNA at High Temperature and Pressure

ChemPhysChem ◽  
2014 ◽  
Vol 16 (1) ◽  
pp. 138-146 ◽  
Author(s):  
Caroline Schuabb ◽  
Melanie Berghaus ◽  
Christopher Rosin ◽  
Roland Winter
Keyword(s):  
Free Energy ◽  
High Temperature ◽  
High Temperature And Pressure ◽  
Conformational Landscape ◽  
Temperature And Pressure

scholarly journals Application of reference-modified density functional theory: Temperature and pressure dependences of solvation free energy

2017 ◽  
Vol 39 (4) ◽  
pp. 202-217 ◽  
Author(s):  
Tomonari Sumi ◽  
Yutaka Maruyama ◽  
Ayori Mitsutake ◽  
Kenji Mochizuki ◽  
Kenichiro Koga
Keyword(s):  
Density Functional Theory ◽  
Free Energy ◽  
Density Functional ◽  
Solvation Free Energy ◽  
Functional Theory ◽  
Temperature And Pressure

Liquid Film Migration in Aluminium Brazing Sheet?

2006 ◽  
Vol 519-521 ◽  
pp. 1151-1156 ◽  
Author(s):  
A. Wittebrood ◽  
S. Desikan ◽  
R. Boom ◽  
Laurens Katgerman
Keyword(s):  
Free Energy ◽  
Corrosion Resistance ◽  
Liquid Film ◽  
Significant Influence ◽  
Clear Explanation ◽  
Distribution Of Elements ◽  
Essential Properties ◽  
Low Levels ◽  
Number Of Publications ◽  
Liquid Film Migration

From literature and own observations it is known that the clad and core alloys that make up aluminium brazing sheet can show severe interaction during the brazing cycle. This interaction leads to a complete re-distribution of elements, changing essential properties like strength and corrosion resistance. This interaction has been reported many times but up to present time no clear explanation is given why this interaction is actually occurring. There are a number of publications addressing the circumstances under which the interaction is more severe. Chemistry and low levels of strain applied before brazing have a significant influence on the severity of the interaction. As a yet possible mechanism behind the interaction Liquid Film Migration is mentioned. The observations done so far are in line with this described mechanism but no ultimate proof has been given so far. The question why the interaction takes place cannot be answered yet, clearly a change of free energy of the system is involved but the mechanism or mechanisms behind the change is unclear.

scholarly journals Kaolin polytypes revisited ab initio

2008 ◽  
Vol 64 (2) ◽  
pp. 131-143 ◽  
Author(s):  
Patrick H. J. Mercier ◽  
Yvon Le Page
Keyword(s):  
Free Energy ◽  
Recent Literature ◽  
Ambient Pressure ◽  
Zero Temperature ◽  
Repeated Application ◽  
Energy Contribution ◽  
Energy Models ◽  
Unknown Reason ◽  
Temperature And Pressure ◽  
Experimental Structure

The well known 36 distinguishable transformations between adjacent kaolin layers are split into 20 energetically distinguishable transformations (EDT) and 16 enantiomorphic transformations, hereafter denoted EDT*. For infinitesimal energy contribution of interactions between non-adjacent layers, the lowest-energy models must result from either (a) repeated application of an EDT or (b) alternate application of an EDT and its EDT*. All modeling, quantum input preparation and interpretation was performed with Materials Toolkit, and quantum optimizations with VASP. Kaolinite and dickite are the lowest-energy models at zero temperature and pressure, whereas nacrite and HP-dickite are the lowest-enthalpy models under moderate pressures based on a rough enthalpy/pressure graph built from numbers given in the supplementary tables. Minor temperature dependence of this calculated 0 K graph would explain the bulk of the current observations regarding synthesis, diagenesis and transformation of kaolin minerals. Other stackings that we list have energies so competitive that they might crystallize at ambient pressure. A homometric pair of energetically distinguishable ideal models, one of them for nacrite, is exposed. The printed experimental structure of nacrite correctly corresponds to the stable member of the pair. In our opinion, all recent literature measurements of the free energy of bulk kaolinite are too negative by ∼ 15 kJ mol−1 for some unknown reason.

Investigating the Wettability of Rapeseed Leaves

2021 ◽  
Vol 37 (3) ◽  
pp. 399-409
Author(s):  
Yong He ◽  
Jianjian Wu ◽  
Shupei Xiao ◽  
Hui Fang ◽  
Qishuai Zheng
Keyword(s):  
Surface Tension ◽  
Free Energy ◽  
Significant Influence ◽  
Leaf Surface ◽  
Contact Angles ◽  
List Type ◽  
Factors Affecting ◽  
Spray Droplets ◽  
Droplet Sizes ◽  
Leaf Wettability

HighlightsContact angles of spray droplets were positively correlated with their surface tension.Wettability of rape leaves was generally poor for most pesticides.Surface structure and free energy determine the hydrophobicity of rape leaves.The size of the spray droplets had no significant influence on rape leaf wettability.Abstract. In order to improve the deposition and adherence of spray droplets on leaf surfaces, the wettability of rapeseed leaves was investigated. We explored the effect of different pesticides and test surfaces on droplet contact angles, and analyzed the effects of leaf surface properties, droplet sizes and the addition of organosilicone adjuvant on wettability. The results indicated that contact angles of different liquids were positively correlated with their surface tension for rapeseed leaves. The wettability of rapeseed leaves was generally poor using different pesticides, but was highest for a fungicide mixture of difenoconazole and propiconazole. The hydrophobicity of rapeseed leaves is largely determined by the complex microstructure and the low surface free energy of the leaves. The size of the spray droplets had no significant influence on the wettability. Moreover, the addition of an organosilicone adjuvant significantly reduced the surface tension of all spray droplets, with the best result for a 50% procymidone solution. In conclusion, the factors affecting rapeseed leaf surface wettability should be considered comprehensively before selecting the appropriate pesticide, so as to improve its utilization rates. Keywords: Contact angle, Leaf surface, Pesticide application, Spray droplet.

Practical applications and Gibbs energy (G)

2020 ◽  
pp. 514-520
Author(s):  
Robert T. Hanlon
Keyword(s):  
Free Energy ◽  
Gibbs Energy ◽  
Gibbs Free Energy ◽  
Constant Temperature ◽  
Chemical Reaction ◽  
Maximum Amount ◽  
Practical Applications ◽  
Temperature And Pressure

Gibbs introduced a new property, later called Gibbs free energy (G), to provide the means by which to quantify the maximum amount of work that can be generated by a given process at constant temperature and pressure. This property can also be used to determine chemical reaction spontaneity.

scholarly journals Synthesis and Colloidal Processing of Nanocrystalline (Y2O3-Stabilized) ZrO2 Powders by a Surface Free Energy Controlled Process

1996 ◽  
Vol 432 ◽  
Author(s):  
Detlef Burgard ◽  
Rüdiger Nass ◽  
Helmut Schmidt
Keyword(s):  
Free Energy ◽  
Tape Casting ◽  
Slip Casting ◽  
Particle Sizes ◽  
Colloidal Processing ◽  
Average Pore ◽  
Growth Technique ◽  
Casting Slip ◽  
Temperature And Pressure ◽  
Processing Techniques

AbstractUsing the controlled growth technique, nanocrystalline ZrO2 powders have een prepared from solution. By variation of the Y-content (0-8 mol %), redispersable monoclinic, tetragonal or cubic ZrO2 powders with particle sizes between 5 and 10 mn were obtained after crystallization at elevated temperature and pressure. Nanodisperse suspensions of the powders have been used for colloidal processing techniques such as tape casting, slip casting or extrusion. The resulting green bodies with densities of 55 % and average pore sizes of 5 nm could be sintered at temperatures below 1100 °C leading to monoclinic, tetragonal or cubic ZrO2 ceramics.

A Statistical Treatment of Crystallization Phenomena in High Polymers

1942 ◽  
Vol 15 (3) ◽  
pp. 462-467
Author(s):  
T. Alfrey ◽  
H. Mark
Keyword(s):  
Free Energy ◽  
Melting Point ◽  
Crystallization Behavior ◽  
Amorphous Material ◽  
Statistical Treatment ◽  
Polymeric Materials ◽  
Crystalline Material ◽  
Crude Model ◽  
Temperature And Pressure ◽  
Degree Of Extension

Abstract An attempt has been made to explain the anomalous crystallization behavior of high polymeric materials on the basis of entropy changes in the amorphous material. The free energy of the amorphous phase depends not only on the temperature and pressure, but also on the degree of extension and the fraction of crystalline material in the sample. A crude model embodying these characteristics was proposed. On the basis of this model, it is possible to explain the unsharp melting point of rubber, the dependence of crystallization on the degree of extension, and the phenomenon of spontaneous extension.

scholarly journals Assessment and Optimization of Collective Variables for Protein Conformational Landscape: GB1 β-hairpin as a Case Study

2018 ◽  
Author(s):  
Navjeet Ahalawat ◽  
Jagannath Mondal
Keyword(s):  
Free Energy ◽  
Molten Globule ◽  
Energy Landscape ◽  
Model System ◽  
Metastable States ◽  
Free Energy Landscape ◽  
Collective Variables ◽  
Folding Mechanism ◽  
Biochemical Systems ◽  
Conformational Landscape

Collective variables (CV), when chosen judiciously, can play an important role in recognizing rate-limiting processes and rare events in any biomolecular systems. However, high dimensionality and inherent complexities associated with such biochemical systems render the identification of an optimal CV a challenging task, which in turn precludes the elucidation of underlying conformational landscape in sufficient details. In this context, a relevant model system is presented by 16residue, β hairpin of GB1 protein. Despite being the target of numerous theoretical and computational studies for understanding the protein folding, the set of CVs optimally characterizing the conformational landscape of, β hairpin of GB1 protein has remained elusive, resulting in a lack of consensus on its folding mechanism. Here we address this by proposing a pair of optimal CVs which can resolve the underlying free energy landscape of GB1 hairpin quite efficiently. Expressed as a linear combination of a number of traditional CVs, the optimal CV for this system is derived by employing recently introduced Timestructured Independent Component Analysis (TICA) approach on a large number of independent unbiased simulations. By projecting the replica-exchange simulated trajectories along these pair of optimized CVs, the resulting free energy landscape of this system are able to resolve four distinct wellseparated metastable states encompassing the extensive ensembles of folded,unfolded and molten globule states. Importantly, the optimized CVs were found to be capable of automatically recovering a novel partial helical state of this protein, without needing to explicitly invoke helicity as a constituent CV. Furthermore, a quantitative sensitivity analysis of each constituent in the optimized CV provided key insights on the relative contributions of the constituent CVs in the overall free energy landscapes. Finally, the kinetic pathways con necting these metastable states, constructed using a Markov State Model, provide an optimum description of underlying folding mechanism of the peptide. Taken together, this work oers a quantitatively robust approach towards comprehensive mapping of the underlying folding landscape of a quintessential model system along its optimized collective variables.

Sign in / Sign up

Export Citation Format

Share Document