“…As an example, the permittivity ε‘ and the dielectric loss ε‘ ‘ of the 100 mM NaDC solution are shown vs frequency at different temperatures in Figures and , respectively. The experimental point trends reveal the presence of the dielectric relaxation usually observed in macromolecular solutions at these frequencies. − The full lines represent the best fit in terms of a Cole−Cole dispersion applying the known equation: 1 Permittivity of the 100 mM NaDC aqueous solution vs frequency at different temperatures. 2 Dielectric loss of the 100 mM NaDC aqueous solution vs frequency at different temperatures.…”
Section: Resultsmentioning
confidence: 98%
“…The experimental point trends reveal the presence of the dielectric relaxation usually observed in macromolecular solutions at these frequencies. [19][20][21][22] The full lines represent the best fit in terms of a Cole-Cole dispersion applying the known equation:…”
The X-ray patterns of lithium (LiDC) and potassium (KDC) deoxycholate fibers, drawn from aqueous micellar solutions, have been interpreted by means of a packing of 8/1 helices formed by trimers. Previously, these helices satisfactorily represented the structure of the sodium (NaDC) and rubidium (RbDC) deoxycholate micellar aggregates. Dielectric measurements show that the trend of the average electric dipole moment µ of a NaDC monomer as a function of temperature and concentration supports a two-structure equilibrium. The high µ values (32-58 D) can be explained by the remarkable hydration of the NaDC micellar aggregates. The µ moderate decrease when the size of the aggregates increases can agree with the presence of small helices but disagrees with the existence of aggregates that are disordered or have a center (or a pseudocenter) of symmetry. Formerly, it was observed that sodium taurodeoxycholate (NaTDC) micellar aggregates, represented by 7/1 helices, formed by trimers, behave similarly. The contribution to the electrical conductivity of NaDC and NaTDC in aqueous solutions containing NaCl tends to zero by increasing the NaCl concentration, denoting strong interactions between Na + ions and anion aggregates. According to the similar 7/1 and 8/1 helices, which have the Na + ions in their inner part, the micellar size and the fraction of Na + ions trapped inside the helices increase together. The aggregate apparent hydrodynamic radius (R h ) increases by increasing the ionic strength in the order LiDC > NaDC > KDC > RbDC. Fibers drawn from solutions containing two cations at the same concentration show that the affinity for the anionic structure seems to follow the order Li + > Na + > K + > Rb + at high ionic strength. The R h values vs the mole fractions of Li + and Rb + or Na + and K + at lower ionic strength are fitted by straight lines. Probably, the free energy gains, associated with the cation and anion transfer from the bulk solution to the micellar aggregates, are almost equal for the four salts at lower ionic strength.
“…As an example, the permittivity ε‘ and the dielectric loss ε‘ ‘ of the 100 mM NaDC solution are shown vs frequency at different temperatures in Figures and , respectively. The experimental point trends reveal the presence of the dielectric relaxation usually observed in macromolecular solutions at these frequencies. − The full lines represent the best fit in terms of a Cole−Cole dispersion applying the known equation: 1 Permittivity of the 100 mM NaDC aqueous solution vs frequency at different temperatures. 2 Dielectric loss of the 100 mM NaDC aqueous solution vs frequency at different temperatures.…”
Section: Resultsmentioning
confidence: 98%
“…The experimental point trends reveal the presence of the dielectric relaxation usually observed in macromolecular solutions at these frequencies. [19][20][21][22] The full lines represent the best fit in terms of a Cole-Cole dispersion applying the known equation:…”
The X-ray patterns of lithium (LiDC) and potassium (KDC) deoxycholate fibers, drawn from aqueous micellar solutions, have been interpreted by means of a packing of 8/1 helices formed by trimers. Previously, these helices satisfactorily represented the structure of the sodium (NaDC) and rubidium (RbDC) deoxycholate micellar aggregates. Dielectric measurements show that the trend of the average electric dipole moment µ of a NaDC monomer as a function of temperature and concentration supports a two-structure equilibrium. The high µ values (32-58 D) can be explained by the remarkable hydration of the NaDC micellar aggregates. The µ moderate decrease when the size of the aggregates increases can agree with the presence of small helices but disagrees with the existence of aggregates that are disordered or have a center (or a pseudocenter) of symmetry. Formerly, it was observed that sodium taurodeoxycholate (NaTDC) micellar aggregates, represented by 7/1 helices, formed by trimers, behave similarly. The contribution to the electrical conductivity of NaDC and NaTDC in aqueous solutions containing NaCl tends to zero by increasing the NaCl concentration, denoting strong interactions between Na + ions and anion aggregates. According to the similar 7/1 and 8/1 helices, which have the Na + ions in their inner part, the micellar size and the fraction of Na + ions trapped inside the helices increase together. The aggregate apparent hydrodynamic radius (R h ) increases by increasing the ionic strength in the order LiDC > NaDC > KDC > RbDC. Fibers drawn from solutions containing two cations at the same concentration show that the affinity for the anionic structure seems to follow the order Li + > Na + > K + > Rb + at high ionic strength. The R h values vs the mole fractions of Li + and Rb + or Na + and K + at lower ionic strength are fitted by straight lines. Probably, the free energy gains, associated with the cation and anion transfer from the bulk solution to the micellar aggregates, are almost equal for the four salts at lower ionic strength.
“…Many types of cations compounds have been used in DNA solvents; for example, NaCl, LiCl, AgNO 2 , CuCl 2 , MnCl 2 , MgCl 2 , arginines, protamine, dyes, lysine, histones, and divalent metals such as Pb, Cd, Ni, Zn, and Hg [ 243 , 251 – 253 ]. The simple inorganic-monovalent cations bind to the DNA molecule near the phosphate backbone to form both a condensed and diffuse sheath.…”
Section: Overview Of the Interaction Of Rf Fields With Biologicalmentioning
The goal of this paper is to overview radio-frequency (RF) electromagnetic interactions with solid and liquid materials from the macroscale to the nanoscale. The overview is geared toward the general researcher. Because this area of research is vast, this paper concentrates on currently active research areas in the megahertz (MHz) through gigahertz (GHz) frequencies, and concentrates on dielectric response. The paper studies interaction mechanisms both from phenomenological and fundamental viewpoints. Relaxation, resonance, interface phenomena, plasmons, the concepts of permittivity and permeability, and relaxation times are summarized. Topics of current research interest, such as negative-index behavior, noise, plasmonic behavior, RF heating, nanoscale materials, wave cloaking, polaritonic surface waves, biomaterials, and other topics are overviewed. Relaxation, resonance, and related relaxation times are overviewed. The wavelength and material length scales required to define permittivity in materials is discussed.
“…The 5 relaxation is weak, occurs around 100 MHz, and is independent of molecular mass. This relaxation is due to the motion of condensed ions within a subunit of the DNA molecule [37,87,88]. The a relaxation occurs for DNA in the range 1 to 100 Hz.…”
Section: Simple Model Of Dipole Momentmentioning
confidence: 99%
“…Protamine stabilizes DNA by neutralizing the phosphate charges in the DNA molecule and thereby increasing the melting temperature [43,44] An empirical fit of the melting temperature Tm of protamine-DNA solutions as a function of salt concentration has been derived [37,45] Tm=^T^+ Cp\ogNa+. Bonincontro et al [37,45] investigated the efi"ects of protamine sulphate (clupeine) and arginine on dielectric relaxation for herring sperm both as a function of temperature (5°C to 40°C) and over a frequency range of 1 MHz to 10 GHz. They fitted the relaxation data to a Cole-Cole model and then estimated the relaxation time r. Bonincontro [45] found that clupeine in safine solution showed relaxation behavior.…”
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