| 1. |
- Saito, M., et al.
(författare)
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Photodissociation of orange i monoanion studied using an electrostatic storage ring
- 2017
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Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 875:4
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Konferensbidrag (refereegranskat)abstract
- Photodissociation of gas-phase orange I monoanions was studied by using an electrostatic storage ring. By comparing their wavelength spectra with those in the liquid phase and with theoretical predictions, it is deduced that the spectra originate from different tautomers of orange I monoanions.
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| 2. |
- Shinwari, M. W., et al.
(författare)
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Electrical Conductance in Biological Molecules
- 2010
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Ingår i: Advanced Functional Materials. - : Wiley. - 1616-3028 .- 1616-301X. ; 20:12, s. 1865-1883
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Tidskriftsartikel (refereegranskat)abstract
- Nucleic acids and proteins are not only biologically important polymers. They have recently been recognized as novel functional materials surpassing conventional materials in many aspects. Although Herculean efforts have been undertaken to unravel fine functioning mechanisms of the biopolymers in question, there is still much more to be done. Here the topic of biomolecular charge transport is presented with a particular focus on charge transfer/transport in DNA and protein molecules. The experimentally revealed details, as well as the presently available theories, of charge transfer/transport along these biopolymers are critically reviewed and analyzed. A summary of the active research in this field is also given, along with a number of practical recommendations.
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| 3. |
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| 4. |
- Starikov, Evgeni B., et al.
(författare)
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DNA Duplex Length and Salt Concentration Dependence of Enthalpy-Entropy Compensation Parameters for DNA Melting
- 2009
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Ingår i: Journal of Physical Chemistry B. - : American Chemical Society (ACS). - 1520-5207 .- 1520-6106. ; 113:33, s. 11375-11377
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Tidskriftsartikel (refereegranskat)abstract
- Systematical differential calorimetry experiments on DNA oligomers with different lengths, and placed in water solutions with various added salt concentrations may, in principle, unravel important information about the structure and dynamics of the DNA and their water-counterion surrounding. With this in mind, to reinterpret the most recent results of calorimetric experiments on DNA oligomers; of such a kind, the recent enthalpy-entropy compensation theory has been used. It is demonstrated that the application of the latter could enable direct estimation of thermodynamic parameters of the microphase transitions connected to the changes in DNA dynamical regimes versus the length of the biopolymers and the ionic strengths of their water solutions, and this calls for much more systematical experimental and theoretical studies in this field.
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| 5. |
- Starikov, Evgeni B., et al.
(författare)
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Enthalpy-entropy compensation: A phantom or something useful?
- 2007
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Ingår i: Journal of Physical Chemistry B. - : American Chemical Society (ACS). - 1520-5207 .- 1520-6106. ; 111:51, s. 14431-14435
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Tidskriftsartikel (refereegranskat)abstract
- In various chemical systems enthalpy-entropy compensation (EEC) is a well-known rule of behavior, although the physical roots of it are still not completely understood. It has been frequently questioned whether EEC is a truly physical phenomenon or a coincidence due to trivial mathematical connections between statistical-mechanical parameters or even simpler, a phantom effect resulting from the misinterpretation of experimental data. Here, we review EEC from a new standpoint and conclude that it may be rationalized in terms of hidden but physically real factors implying a Carnot-cycle model in which a micro-phase transition (MPT) plays a crucial role. Examples of such MPTs underlying physically valid EEC should be typically cooperative processes in supramolecular aggregates, like changes of structured water at hydrophobic surfaces, conformational transitions upon ligand-biopolymer binding, and so forth. The MPT notion could help rationalize the occurrence of EEC in connection with hydration and folding of proteins, functioning of molecular motors, and similar phenomena.
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| 6. |
- Starikov, Evgeni B., et al.
(författare)
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Entropy-enthalpy compensation as a fundamental concept and analysis tool for systematical experimental data
- 2012
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Ingår i: Chemical Physics Letters. - : Elsevier BV. - 0009-2614. ; 538, s. 118-120
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Tidskriftsartikel (refereegranskat)abstract
- Enthalpy-entropy compensation (EEC) has a definite physical sense. Here, we review EEC from a new standpoint, using the notion of correlation. The latter has two basic meanings: (a) 'A' is correlated to 'B' means 'A' results from 'B' or vice versa; (b) this same means there is some real, but hidden 'C' in connection to both 'A' and 'B'). In accordance with the interpretation (b), we try rationalizing EEC in terms of hidden, but physically real factors.
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| 7. |
- Starikov, Evgeni B., et al.
(författare)
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Entropy-enthalpy compensation may be a useful interpretation tool for complex systems like protein-DNA complexes: An appeal to experimentalists
- 2012
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 100:19
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Tidskriftsartikel (refereegranskat)abstract
- In various chemical systems, enthalpy-entropy compensation (EEC) is a well-known rule of behavior, although the physical roots of it are still not completely understood. It has been frequently questioned whether EEC is a truly physical phenomenon or a coincidence due to trivial mathematical connections between statistical-mechanical parameters-or even simpler: A phantom effect resulting from the misinterpretation of experimental data. Here, we review EEC from another standpoint using the notion of correlation, which is essential for the method of factor analysis but is not conventional in physics and chemistry. We conclude that the EEC may be rationalized in terms of hidden (not directly measurable with the help of the current experimental set-up) but physically real factors, implying a Carnot-cycle model in which a micro-phase transition (MPT) plays a crucial role. Examples of such MPTs underlying physically valid EEC should be typically cooperative processes in supramolecular aggregates, like changes of structured water at hydrophobic surfaces, conformational transitions upon ligand-biopolymer binding, and so on. The MPT notion could help rationalize the occurrence of EEC in connection with hydration and folding of proteins, enzymatic reactions, functioning of molecular motors, DNA de-and rehybridization, as well as similar phenomena.
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| 8. |
- Starikov, Evgeni B.
(författare)
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'Entropy is anthropomorphic': does this lead to interpretational devalorisation of entropy-enthalpy compensation?
- 2013
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Ingår i: Monatshefte für Chemie. - : Springer Science and Business Media LLC. - 0026-9247 .- 1434-4475. ; 144:1, s. 97-102
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Tidskriftsartikel (refereegranskat)abstract
- It is presently well recognised that the concept of entropy can be formulated in many different ways-and this is definitely dependent on the problem to be solved. Does this fact really mean that the entropy-enthalpy compensation underlying physically/chemically valid iso-kinetic, iso-selective, iso-equilibrium relationships immediately loses its interpretational value? By invoking the well forgotten (and sometimes even simply unknown!) work by G.A. Linhart, we would like to demonstrate that in effect entropy's anthropomorphicity opens interesting interpretational opportunities.
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| 9. |
- Starikov, Evgeni B.
(författare)
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Many Faces of Entropy or Bayesian Statistical Mechanics
- 2010
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Ingår i: ChemPhysChem. - : Wiley. - 1439-7641 .- 1439-4235. ; 11:16, s. 3387-3394
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Tidskriftsartikel (refereegranskat)abstract
- Some 80-90 years ago, George A. Linhart, unlike A. Einstein, P. Debye, M. Planck and W. Nernst, managed to derive a very simple, but ultimately general mathematical formula for heat capacity versus temperature from fundamental thermodynamic principles, using what we would nowadays dub a "Bayesian approach to probability". Moreover, he successfully applied his result to fit the experimental data for diverse substances in their solid state over a rather broad temperature range. Nevertheless, Linhart's work was undeservedly forgotten, although it represents a valid and fresh standpoint on thermodynamics and statistical physics, which may have a significant implication for academic and applied science.Undeservedly forgotten: George A. Linhart's publications some 80-90 years ago in which-unlike Einstein, Debye, Planck and Nernst-he succeeded in deriving a simple, but ultimately general mathematical formula for heat capacity versus temperature from fundamental thermodynamic principles, using what we would nowadays dub a "Bayesian approach to probability", became totally forgotten, although they represent a valid and fresh standpoint on thermodynamics and statistical physics. The aim of this essay is to restore the memory of these great works
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| 10. |
- Starikov, Evgeni B., et al.
(författare)
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Physical Rationale Behind the Nonlinear Enthalpy-Entropy Compensation in DNA Duplex Stability
- 2009
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Ingår i: Journal of Physical Chemistry B. - : American Chemical Society (ACS). - 1520-5207 .- 1520-6106. ; 113:14, s. 4698-4707
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Tidskriftsartikel (refereegranskat)abstract
- The physical-chemical sense of nonlinear entropy-enthalpy compensation based upon the standard thermodynamical parameters of high-temperature melting for doublet units in DNA duplexes has been considered. We are able to show that there are three, with no other constraints equally plausible, principal levels of DNA melting/hybridization description. First, DNA structure assembly/disassembly can be seen from the viewpoint of the conventional equilibrium thermodynamics without taking special care of the heat capacity Delta C-p value (by simply setting it equal to zero). Second, it is possible to assume that the Delta C-p is finite, but independent of temperature. At this approximation level the high-temperature DNA melting cannot be described, but only some special transition between metastable states of DNA duplexes in water solutions in the vicinity of ice melting point. Third, both the latter transition and the high-temperature DNA melting can be reproduced by one and the same approach, if the Delta C-p is assumed to be temperature dependent. These three approximation levels are equally justified from the nonlinear entropy-enthalpy compensation standpoint and by a generalized theory of temperature effects on themodynamical stability as is outlined here. Applicability of each of the approximation levels involved is discussed.
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