scholarly journals Model for Deformation of Cells from External Electric Fields at or Near Resonant Frequencies

2020 ◽  
Author(s):  
L. Martinez ◽  
A. Dhruv ◽  
L. Lin ◽  
E. Balaras ◽  
M. Keidar
Keyword(s):  
Electric Field ◽  
Cancer Cells ◽  
Electric Fields ◽  
High Energy ◽  
Atmospheric Plasma ◽  
Maximum Effect ◽  
Viscoelastic Response ◽  
Resonant Frequencies ◽  
Wave Source ◽  
External Electric Fields

AbstractThis paper presents a numerical model to investigate the deformation of biological cells by applying external electric fields operating at or near cell resonant frequencies. Cells are represented as pseudo solids with high viscosity suspended in liquid media. The electric field source is an atmospheric plasma jet developed inhouse, for which the emitted energy distribution has been measured.Viscoelastic response is resolved in the entire cell structure by solving a deformation matrix assuming an isotropic material with a prescribed modulus of elasticity. To investigate cell deformation at resonant frequencies, one mode of natural cell oscillation is considered in which the cell membrane is made to radially move about its eigenfrequency. An electromagnetic wave source interacts with the cell and induces oscillation and viscoelastic response. The source carries energy in the form of a distribution function which couples a range of oscillating frequencies with electric field amplitude.Results show that cell response may be increased by the external electric field operating at or near resonance. In the elastic regime, response increases until a steady threshold value, and the structure moves as a damped oscillator. Generally, this response is a function of both frequency and magnitude of the source, with a maximum effect found at resonance. To understand the full effect of the source energy spectrum, the system is solved by considering five frequency-amplitude couplings. Results show that the total solution is a nonlinear combination of the individual solutions. Additionally, sources with different signal phases are simulated to determine the effect of initial conditions on the evolution of the system, and the result suggests that there may be multiple solutions within the same order of magnitude for elastic response and velocity. Cell rupture from electric stress may occur during application given a high energy source.SignificanceCold atmospheric plasma jets (CAPJs) have been widely researched for their potential applications in cancer therapy. Existing research has focused mainly on the ability of CAPJs to deliver a mixture of reactive species which can be absorbed by cancer cells and induce cell death. The objective of our study is to investigate the mechanical effect of CAPJ electromagnetic (EM) waves on interacting cells. By coupling the EM waves associated with plasma frequency and cell viscoelastic response, we have developed a numerical tool to investigate cell damage either by mechanical or thermal loads. This work is motivated by the promise of EM waves to function as a sensitizing agent for cancer cells in preparation for chemotherapy.

scholarly journals Molecular Dynamics Simulations of Liquid-Liquid Interfaces in an Electric Field: the Water-1,2-Dichloroethane Interface

2020 ◽  
Author(s):  
Paolo Raiteri ◽  
Peter Kraus ◽  
Julian Gale
Keyword(s):  
Molecular Dynamics ◽  
Electric Field ◽  
Molecular Dynamics Simulations ◽  
External Electric Field ◽  
Electric Fields ◽  
Liquid Interfaces ◽  
Ewald Summation ◽  
External Electric Fields ◽  
Simulation Cell ◽  
Dynamics Simulations

Molecular dynamics simulations of the liquid-liquid interface between water and 1,2-Dichloroethane in the presence of weak external electric fields.<div>The effect of the use of 3D periodic Ewald summation and the effect of the simulation setup are discussed.</div><div>A new simple geometric method for designing the simulation cell is proposed. This method was thoroughly tested shown that it mitigates any artefacts to the use of 3D Ewald summation with external electric field.</div>

scholarly journals Possibility of realizing superionic ice VII in external electric fields of planetary bodies

2020 ◽  
Vol 6 (21) ◽  
pp. eaaz2915 ◽  
Author(s):  
Zdenek Futera ◽  
John S. Tse ◽  
Niall J. English
Keyword(s):  
Molecular Dynamics ◽  
Electric Field ◽  
Ab Initio ◽  
Electric Fields ◽  
State Of The Art ◽  
Ab Initio Molecular Dynamics ◽  
Theoretical Studies ◽  
Potential Candidate ◽  
External Electric Fields ◽  
Ice Phase

In a superionic (SI) ice phase, oxygen atoms remain crystallographically ordered while protons become fully diffusive as a result of intramolecular dissociation. Ice VII’s importance as a potential candidate for a SI ice phase has been conjectured from anomalous proton diffusivity data. Theoretical studies indicate possible SI prevalence in large-planet mantles (e.g., Uranus and Neptune) and exoplanets. Here, we realize sustainable SI behavior in ice VII by means of externally applied electric fields, using state-of-the-art nonequilibrium ab initio molecular dynamics to witness at first hand the protons’ fluid dance through a dipole-ordered ice VII lattice. We point out the possibility of SI ice VII on Venus, in its strong permanent electric field.

The extended Rayleigh theory of the oscillation of liquid droplets

1981 ◽  
Vol 104 ◽  
pp. 295-309 ◽  
Author(s):  
C. A. Morrison ◽  
R. P. Leavitt ◽  
D. E. Wortman
Keyword(s):  
Dielectric Constant ◽  
Electric Field ◽  
Frequency Shift ◽  
Electric Fields ◽  
Optical Field ◽  
Liquid Droplets ◽  
Dynamical Equations ◽  
Resonant Frequencies ◽  
Small Oscillations ◽  
Liquid Drops

The Rayleigh theory of oscillation of liquid drops is extended to include the effects of viscosity and a uniform external electric field. The resonant frequencies of the modes of the drop are shown to be shifted by the electric field. The magnitude and sign of the frequency shift depends on the dielectric constant of the drop. The condition for instability of drops in large electric fields is given and found to differ from that given by previous workers. This difference is attributed to the assumption by previous workers that the drops, under the influence of an electric field, distort into ellipsoids of revolution about the field direction. The dynamical equations are derived and the solution for small oscillations is given in an oscillating field and in an amplitude-modulated optical field.

scholarly journals Cell Death and Induced p53 Expression in Oral Cancer, HeLa, and Bone Marrow Mesenchyme Cells under the Exposure to Noncontact Electric Fields

2017 ◽  
Vol 4 (3-4) ◽  
pp. 161-170 ◽  
Author(s):  
Sahudi Abdul Mujib ◽  
Firman Alamsyah ◽  
Warsito Purwo Taruno
Keyword(s):  
Bone Marrow ◽  
Cell Death ◽  
Oral Cancer ◽  
Electric Field ◽  
Cancer Cells ◽  
Electric Fields ◽  
Field Exposure ◽  
P53 Expression ◽  
Culture Cells ◽  
Mesenchyme Cells

Background: p53 acts as a transcription factor to regulate the expression of genes that modulate various cellular activities. The proliferation of cancer cells has been inhibited under the exposure to low-intensity (18 peak-to-peak voltage) and intermediate-frequency (100 KHz) electric fields generated between 2 capacitive electrodes. Therefore, the aims of this study were to observe the molecular mechanism of cell death caused by noncontact electric field exposure and to determine whether p53 protein can serve as a biomarker for this exposure or not. Methods: Oral squamous cell carcinoma, HeLa, and bone marrow mesenchyme cells were exposed to noncontact electric fields of Electro-Capacitive Cancer Therapy (ECCT) for 24 h. To observe the mechanism of cell death caused by ECCT, immunocytochemistry of p53 was performed, and the p53 expression was evaluated using immunoreactive score (IRS) calculation. Results: Electric field exposure by ECCT increased the percentage of dead cells in oral cancer cells (18.39%), HeLa cells (6.60%), and bone marrow mesenchyme cells (34.05%) with statistical significance using the independent t test compared to each control group. The IRS of p53 in oral cancer, HeLa, and bone marrow mesenchyme cultures were 10.50, 11.25, and 4.94, respectively. Conclusion: The high IRS shown in the treated oral cancer and HeLa culture cells may suggest that p53 expression in these culture cells is associated with the cell death mechanism induced by the exposure to noncontact electric fields, and the increased cell death in these culture cells may correlate with the IRS.

Tuning the inter-molecular charge transfer, second-order nonlinear optical and absorption spectra properties of a π-dimer under an external electric field

2017 ◽  
Vol 19 (47) ◽  
pp. 31958-31964 ◽  
Author(s):  
Feng-Wei Gao ◽  
Hong-liang Xu ◽  
Zhong-Min Su
Keyword(s):  
Charge Transfer ◽  
Electric Field ◽  
Electric Fields ◽  
Nonlinear Optical ◽  
Stability Control ◽  
External Electric Fields ◽  
Optical Responses ◽  
Molecular Charge ◽  
Spectra Properties ◽  
The Stability

Different strengths of external electric fields enhance the stability, control the inter-molecular charge transfer and strengthen the nonlinear optical responses of a π-dimer.

The Influence of External Electric Field on Heat Transfer at Boiling on Non-Uniform Surfaces

2010 ◽  
Author(s):  
Alexey A. Eronin ◽  
Stanislav P. Malyshenko ◽  
Anton I. Zhuravlev
Keyword(s):  
Heat Transfer ◽  
Electric Field ◽  
Electric Fields ◽  
Heated Surface ◽  
Transfer Enhancement ◽  
Two Phase ◽  
Major Mechanism ◽  
External Electric Fields ◽  
Different Types ◽  
Field Traps

Characteristics of heat transfer and hydrodynamics of boiling of liquid nitrogen on the surfaces with different types of non-uniformities at the presence of external electric fields are experimentally investigated. It is shown that the formation of field traps is a major mechanism of heat transfer enhancement. And this effect result in noticeable change of two-phase hydrodynamics in vicinity of heated surface.

scholarly journals Heterogeneous Intramolecular Electric Field as a Descriptor of Diels-Alder Reactivity

2020 ◽  
Author(s):  
Matthew Hennefarth ◽  
Anastassia N. Alexandrova
Keyword(s):  
Electric Field ◽  
Electron Density ◽  
Electric Fields ◽  
Alder Reaction ◽  
Diels Alder ◽  
Charge Movement ◽  
External Electric Fields ◽  
Topological Features ◽  
Diels Alder Reaction ◽  
Kinetics Of

<div> <div> <div> <p>External electric fields have proven to be an effective tool in catalysis, on par with pressure and temperature, affecting the thermodynamics and kinetics of a reaction. However, fields in molecules are complicated heterogeneous vector objects, and there is no universal recipe for grasping the exact features of these fields that implicate reactivity. Herein, we demonstrate that topological features of the heterogeneous electric field within the reactant state, as well as of the quantum mechanical electron density – a scalar reporter on the field experienced by the system – can be identified as rigorous descriptors of the reactivity to follow. We scrutinize specifically the Diels-Alder reaction. Its 3-D nature and the lack of a singular directionality of charge movement upon barrier crossing makes the effect of the electric field not obvious. We show that the electric field topology around the dienophile double bond, and the associated changes in the topology of the electron density in this bond are predictors of the reaction barrier. They are also the metrics by which to rationalize and predict how the external field would inhibit or enhance the reaction. The findings pave the way toward designing external fields for catalysis, as well as reading the reactivity without an explicit mechanistic interrogation, for a variety of reactions. </p> </div> </div> </div>

scholarly journals External-Electric-Field-Enhanced Uniformity and Deposition Rate of a TiO2 Film Prepared by the Sparking Process

2018 ◽  
Vol 63 (6) ◽  
pp. 531 ◽  
Author(s):  
W. Thongpan ◽  
T. Kumpika ◽  
E. Kantarak ◽  
A. Panthawan ◽  
P. Pooseekheaw ◽  
...  
Keyword(s):  
Electric Field ◽  
External Electric Field ◽  
Electric Fields ◽  
Deposition Rate ◽  
Tio2 Films ◽  
Dc Voltage ◽  
External Electric Fields ◽  
Deposited Film ◽  
Field Area ◽  
Scanning Electron

We have used an external electric field to increase both the uniformity and deposition rate of TiO2 films. The experiment is carried out by sparking-off titanium wires with a high dc voltage of 1 kV (field Eint = 10 kV/cm) and a limited current of 3 mA. The external electric fields (Eext) of 3, 6, and 9 kV/cm were applied to the sparking system for 1–5 hours. The as-deposited film morphology was characterized by scanning electron microscopy. The results clearly show that the films are only deposited on the external electric field area. Furthermore, the deposition rate of the films increased from 40.7% to 77.8% in the presence of the external electric field of 9 kV/cm. The effects of an external electric field on both the deposition rate and uniformity of films are investigated and described.

scholarly journals Molecular Dynamics Simulations of Liquid-Liquid Interfaces in an Electric Field: the Water-1,2-Dichloroethane Interface

2020 ◽  
Author(s):  
Paolo Raiteri ◽  
Peter Kraus ◽  
Julian Gale
Keyword(s):  
Molecular Dynamics ◽  
Electric Field ◽  
Molecular Dynamics Simulations ◽  
External Electric Field ◽  
Electric Fields ◽  
Liquid Interfaces ◽  
Ewald Summation ◽  
External Electric Fields ◽  
Simulation Cell ◽  
Dynamics Simulations

Molecular dynamics simulations of the liquid-liquid interface between water and 1,2-Dichloroethane in the presence of weak external electric fields.<div>The effect of the use of 3D periodic Ewald summation and the effect of the simulation setup are discussed.</div><div>A new simple geometric method for designing the simulation cell is proposed. This method was thoroughly tested shown that it mitigates any artefacts to the use of 3D Ewald summation with external electric field.</div>

scholarly journals The optical tweezer of skyrmions

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Xi-Guang Wang ◽  
Levan Chotorlishvili ◽  
Vitalii K. Dugaev ◽  
Arthur Ernst ◽  
Igor V. Maznichenko ◽  
...  
Keyword(s):  
Electric Field ◽  
External Electric Field ◽  
Electric Fields ◽  
Essential Role ◽  
Optical Tweezer ◽  
Magnetic Texture ◽  
Dm Interaction ◽  
Micromagnetic Simulations ◽  
Magnetic Structures ◽  
External Electric Fields

Abstract In a spin-driven multiferroic system, the magnetoelectric coupling has the form of effective dynamical Dzyaloshinskii–Moriya (DM) interaction. Experimentally, it is confirmed, for instance, for Cu2OSeO3, that the DM interaction has an essential role in the formation of skyrmions, which are topologically protected magnetic structures. Those skyrmions are very robust and can be manipulated through an electric field. The external electric field couples to the spin-driven ferroelectric polarization and the skyrmionic magnetic texture emerged due to the DM interaction. In this work, we demonstrate the effect of optical tweezing. For a particular configuration of the external electric fields it is possible to trap or release the skyrmions in a highly controlled manner. The functionality of the proposed tweezer is visualized by micromagnetic simulations and model analysis.

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