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Topic Review
Thermodynamic Insights into Symmetry Breaking
Symmetry breaking is a phenomenon that is observed in various contexts, from the early universe to complex organisms, and it is considered a key puzzle in understanding the emergence of life. The importance of this phenomenon is underscored by the prevalence of enantiomeric amino acids and proteins. The presence of enantiomeric amino acids and proteins highlights its critical role. However, the origin of symmetry breaking has yet to be comprehensively explained, particularly from an energetic standpoint.  Therefore, a novel approach is explored by considering energy dissipation, specifically the lost free energy, as a crucial factor in elucidating symmetry breaking. A comprehensive thermodynamic analysis applicable to all scales from elementary particles to aggregate structures such as crystals is performed, we present experimental evidence establishing a direct link between nonequilibrium free energy and energy dissipation during the formation of the structures. Results emphasize the pivotal role of energy dissipation, not only as an outcome but as the trigger for symmetry breaking. This insight suggests that understanding the origins of complex systems, from cells to living beings and the universe itself, requires a lens focused on nonequilibrium processes  
  • 118
  • 15 Apr 2024
Topic Review
Thermal Analysis to 3D Printing
Thermal analysis (TA) comprises various measuring techniques with a common feature: the measure of the material response when heated or cooled (or, in some cases, held isothermally).
  • 1.1K
  • 29 Mar 2022
Topic Review
Theoretical Consideration of Molecular Helicenes and Their Properties
Some theoretical studies of properties of helicenes are considered. It was shown that helicenes are promising molecules for use as components of various nanodevices, due to the continuous π-system having a helical topology. Peripheral modifications of the edges make it possible to change the properties of helicenes over a wide range. The transition to polymeric helicenes is also considered.
  • 231
  • 14 Sep 2023
Topic Review
The Pnictogen Bond in Metal Halide Perovskites
The pnictogen bond, a somewhat overlooked supramolecular chemical synthon known since the middle of the last century, is one of the promising types of non-covalent interactions yet to be fully understood by recognizing and exploiting its properties for the rational design of novel functional materials. Its bonding modes, energy profiles, vibrational structures and charge density topologies, among others, have yet to be comprehensively delineated, both theoretically and experimentally.
  • 274
  • 14 Feb 2023
Topic Review
The Nitrogen Bond
The nitrogen bond in chemical systems occurs when there is evidence of a net attractive interaction between the electrophilic region associated with a covalently or coordinately bound nitrogen atom in a molecular entity and a nucleophile in another, or the same molecular entity. It is the first member of the family of pnictogen bonds formed by the first atom of the pnictogen family, Group 15, of the periodic table, and is an inter- or intra-molecular non-covalent interaction.
  • 1.9K
  • 25 Mar 2022
Topic Review
The Hydrophobic Effects
Hydrophobic interactions are involved in and believed to be the fundamental driving force of many chemical and biological phenomena in aqueous environments.
  • 545
  • 01 Nov 2022
Topic Review
The Design of Ni-Based Single Crystal Superalloys
The most important performance characteristics of heat-resistant alloys (HRAs) are creep and fatigue resistance, which are very complex functions of chemical composition and microstructure. The microstructure of metal HRAs, among which the first place is occupied by Ni-based alloys, usually consists of two main phases: a solid solution based on the main element containing alloying elements (matrix), and a strengthening phase, which is usually used as intermetallides, carbides and silicides.
  • 899
  • 17 Jan 2022
Topic Review
The Coupling in Biological Membranes
Cell membrane structure is proposed as a lipid matrix with embedded proteins, and thus, their emerging mechanical and electrostatic properties are commanded by lipid behavior and their interconnection with the included and absorbed proteins, cytoskeleton, extracellular matrix and ionic media. Structures formed by lipids are soft, dynamic and viscoelastic, and their properties depend on the lipid composition and on the general conditions, such as temperature, pH, ionic strength and electrostatic potentials. The dielectric constant of the apolar region of the lipid bilayer contrasts with that of the polar region, which also differs from the aqueous milieu, and these changes happen in the nanometer scale. Besides, an important percentage of the lipids are anionic, and the rest are dipoles or higher multipoles, and the polar regions are highly hydrated, with these water molecules forming an active part of the membrane. Therefore, electric fields (both, internal and external) affects membrane thickness, density, tension and curvature, and conversely, mechanical deformations modify membrane electrostatics. As a consequence, interfacial electrostatics appears as a highly important parameter, affecting the membrane properties in general and mechanical features in particular.
  • 632
  • 12 Jul 2021
Topic Review
The Catalytic Interface Layer for Bipolar Membrane
Bipolar membranes, a new type of composite ion exchange membrane, contain an anion exchange layer, a cation exchange layer and an interface layer. The interface layer or junction is the connection between the anion and cation exchange layers. Water is dissociated into protons and hydroxide ions at the junction, which provides solutions to many challenges in the chemical, environmental and energy fields. By combining bipolar membranes with electrodialysis technology, acids and bases could be produced with low cost and high efficiency. The interface layer or junction of bipolar membranes (BPMs) is the connection between the anion and cation exchange layers, which the membrane and interface layer modification are vital for improving the performance of BPMs.
  • 522
  • 02 Sep 2022
Topic Review
Tautomerism Detected by NMR
Tautomerism is typically the relocation of a light atom, often hydrogen, at the same time as a rearrangement of the electronic structure.  Typical examples are acetylacetone and acetone. This entry gives a short introduction to how to detect and describe a tautomeric equilibrium using Nuclear Magnetic Resonance (NMR). Typical parameters used are chemical shifts (1H,13C,15N,19F and 17O) one-bond coupling constants and isotope effects on chemical shifts.
  • 9.2K
  • 29 Oct 2020
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