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Dynamics of the Davydov’s soliton in external oscillating magnetic field
... [38][39][40][41], in the considered here problem the nonlinearity plays essential role, and, therefore, we intend to avoid considering weakly nonlinear limit, but use the nonlinear perturbation theory. 37 It has been shown in Ref. 31 that in the zero order approximation the solution of Eq. (20) has a standard form: (29) in which the arguments are defined by the relations ...
Some less-known facts of the Wave of Translation discovery and a brief review of the advancement of the theory of Davydov’s solitons are given. Dynamics of the Davydov’s soliton in an external oscillating in time magnetic field is investigated. The analysis shows that soliton wave function is a superposition of the electron plane wave in the plane perpendicular to the molecular chain, and longitudinal component of the wave function, which satisfies the modified Nonlinear Schrödinger equation. It is shown that soliton width and amplitude are constant, while its velocity and phase are oscillating in time functions with the frequency of the main harmonic determined by the magnetic field frequency. Furthermore, in the presence of the energy dissipation, soliton velocity is bound from above due to the balance of the energy gain from the magnetic field, and its loss because of the radiation of linear sound waves and energy dissipation. Soliton radiation due to time-depending velocity is calculated and shown to be the most intensive at the resonant frequency of the magnetic field. Such complex impact of time-depending magnetic fields on charge transport, provided by solitons, can affect functioning of the devices based on low-dimensional molecular systems. These results suggest the physical mechanism of the resonant therapeutic effects of oscillating magnetic fields as the resonant impact of the magnetic field on the dynamics of solitons, which provide charge transport along biological macromolecules in the redox processes.
Within the framework of AdS/CFT correspondence we considered large N limits of conformal field
theories in d dimensions which described in terms of supergravity on the product of AdS space with
a compact manifold. An important example of such correspondence is equivalence between N =
4 super Yang-Mills theory in four dimensions and Type IIB superstring theory on AdS5×S5
The aim of the study was to evaluate the interconnections between local Schumann resonances of the Earth’s magnetic field and episodes of kidney disease. Materials and Methods: Study participants included 716 males and 624 females who had episodes of kidney disease during the period of 1 January 2021 to 31 December 2021 and attended the Department of Nephrology at the Hospital of Lithuanian University of Health Sciences, Kauno klinikos. Time varying magnetic field data was collected at the magnetometer site located in Lithuania. Results and Conclusions: The study results support the hypothesis that the Earth’s magnetic field has a relationship between the number of nephrology patient hospitalizations per week and the average weekly local Schumann resonances strength in different frequency ranges. Working hypotheses are proposed for the mechanisms of the influence of the Earth’s electromagnetic field on kidney function: а) quantum mechanical features of the atomic composition of renal tissue molecules determine a kidney-specific reaction; b) cyclotron resonance mechanism; c) resonant response of cells of morphological structures of kidney tissue to external bioactive frequencies in the range of 6-8 Hz; d) mechanism of indirect influence of blood as a magnetically saturated medium.
This report summarizes effects of anthropogenic electric, magnetic, and electromagnetic fields in the frequency range from 0 to 100 MHz on flora and fauna, as presented at an international workshop held on 5–7 November in 2019 in Munich, Germany. Such fields may originate from overhead powerlines, earth or sea cables, and from wireless charging systems. Animals and plants react differentially to anthropogenic fields; the mechanisms underlying these responses are still researched actively. Radical pairs and magnetite are discussed mechanisms of magnetoreception in insects, birds, and mammals. Moreover, several insects as well as marine species possess specialized electroreceptors, and behavioral reactions to anthropogenic fields have been reported. Plants react to experimental modifications of their magnetic environment by growth changes. Strong adverse effects of anthropogenic fields have not been described, but knowledge gaps were identified; further studies, aiming at the identification of the interaction mechanisms and the ecological consequences, are recommended.
The history of the experimental study of nonlinear lattice excitations in layered silicate materials, when exposed to swift particles of appreciable momentum is described briefly. For brevity, and because of the difficulty of studying the structure of the lattice excitations, the term quodon was adopted to reflect their ballistic and quasione-dimensional propagative nature. Quodons in muscovite were observed experimentally. Eventually, it was deduced that the lattice excitations were carrying an electric charge. This led to the prediction of hyperconductivity (HC) in which charge is carried ballistically by neutral, mobile lattice excitations in absence of a driving electromotive force and at any temperature. HC was later observed experimentally. For practical applications of HC, it is necessary to encase the HC material in an insulating sheath. This focused attention on the behavior of insulating materials in the presence of quodons. These could enter the sheath by direct contact with the HC material or by the impact of the swift particles. It was found that quodons can exist and propagate in many different materials, perhaps all, but their behavior can vary dramatically. This universality and charge neutrality, together with their unexpected existence in the excellent insulator polytetrafluoroethylene, probably accounts for the delay in finding evidence of their existence.
The Davydov–Kyslukha nonlinear exciton-phonon model on a regular one-dimensional lattice is asserted to be the driving force for the development of integrable multi-component nonlinear dynamical systems encompassing excitonic, vibrational and orientational degrees of freedom. The two most representative quasi-one-dimensional integrable multi-component nonlinear systems inspired by the Davydov–Kyslukha model are presented explicitly in their concise Hamiltonian forms. The new six-subsystem integrable nonlinear model on a regular quasi-one-dimensional lattice is proposed and its derivation based upon the appropriate zero-curvature representation is presented. The constructive aspect of the famous Davydov motto is illustrated by the examples of semi-discrete integrable nonlinear dynamical systems canonicalizeable via the proper point transformations to the physically motivated field variables.
Solitons are known to play the role of elementary excitations for one-dimensional ordered systems, like atomic chains with charge or spin ordering. The main characteristic of solitons is their dispersion relation, dependence of soliton energy on the linear momentum. Topological kink-type solitons are the simplest and most important for the description of many physical properties of one-dimensional magnets. Here we provide a detailed analysis of solitons in some general class of magnets, ferrimagnets with the spin compensation point. The nonlinear spin dynamics of ferrimagnets are examined using a nonlinear sigma-model for the antiferromagnetic vector, which is a generalization of the Landau-Lifshitz equation for ferromagnets and sigma-model for the antiferromagnets. The characteristic features of this equation are governed by the value of the compensation parameter, describing the rate of compensation of spins of sublattices. The dispersion relation for kink-type solitons appears to be quite nontrivial, including periodic dispersion law for continuum model of magnet or the presence of ending point for kink spectrum.
In this paper, the limit behavior of solutions for the nonlinear Schrödinger equation in is studied. Here is an - subcritical exponent and the coefficients , are periodic functions. The coefficient is further assumed to be one sign, bounded, and bounded away from zero. We prove local and global well-posedness results in and that the solution converges as to the solution of the limiting equation with the same initial condition. Furthermore, we also prove that if the limiting solution is global and has a certain decay property, then is also global for sufficiently large.
The multi-level microstructure of conjugated polymers is the most critical parameter determining the charge transport property in field-effect transistors (FETs). However, controlling the hierarchical microstructures and the structural evolution remains a significant challenge. In this perspective, we discuss the key aspects of multi-level microstructures of conjugated polymers towards high-performance FETs. We highlight the recent progress about molecular structures, solution-state aggregation, and polymer crystal structures, representing the multi-level microstructures of conjugated polymers. By tuning polymer hierarchical microstructures, we attempt to provide several guidelines for developing high-performance polymer FETs and polymer electronics.
While traditional approaches for disease management in the era of modern medicine have saved countless lives and enhanced patient well‐being, it is clear that there is significant room to improve upon the current status quo. For infectious diseases, the steady rise of antibiotic resistance has resulted in super pathogens that do not respond to most approved drugs. In the field of cancer treatment, the idea of a cure‐all silver bullet has long been abandoned. As a result of the challenges facing current treatment and prevention paradigms in the clinic, there is an increasing push for personalized therapeutics, where plans for medical care are established on a patient‐by‐patient basis. Along these lines, vaccines, both against bacteria and tumors, are a clinical modality that could benefit significantly from personalization. Effective vaccination strategies could help to address many challenging disease conditions, but current vaccines are limited by factors such as a lack of potency and antigenic breadth. Recently, researchers have turned toward the use of biomimetic nanotechnology as a means of addressing these hurdles. Recent progress in the development of biomimetic nanovaccines for antibacterial and anticancer applications is discussed, with an emphasis on their potential for personalized medicine. Personalized medicine is transforming how diseases are managed in the clinic. At the same time, biomimetic nanotechnology offers many advantages that can be leveraged toward the design of more effective medical interventions. Recent developments in biomimetic nanovaccines against cancer and bacterial infections are discussed, with a specific emphasis on potential avenues for personalization.
A combined action of weak static and alternating low-fraquency magnetic fields on ionic currents through aqueous amino acid solutions (asparagine, argenine, glutamic acid, and tyrosine) were studied. Distinct (30-50% over the background current) narrow-band peaks for the frequencies close to the cyclotronic ones for the ionized forms of the corresponding amino acids were seen on the current versus frequency curve with alternating field direction being parallel to the static field. No other peaks were observed. The effects were completely reproducible. No effects were observed for perpendicular fields or absence of the static field. The effects were only observed for very weak alternating fields (0.05 mcT). The effect vanishes on increasimg the alternating field amplitude.
In this paper we describe briefly the basic aspects of magnetic resonance
therapy, registered as TMR therapy. Clinical studies have shown that
application of this therapy significantly accelerates wound healing and, in
particular, healing of the diabetic foot disease. To understand the working
principle of this therapy, we analyze relevant to it biological effects
produced by magnetic fields. Based on these data, we show that there is a
hierarchy of the possible physical mechanisms, which can produce such effects.
The mutual interplay between the mechanisms can lead to a synergetic outcome
delayed in time, which can affect the physiological state of the organism. In
particular, we show that soliton mediated charge transport during the redox
processes in living organisms is sensitive to magnetic fields, so that such
fields can facilitate redox processes in particular, and can stimulate the
healing effect of the organism in general. This and other non-thermal resonant
mechanisms of the biological effects of magnetic fields are summarized as the
working principle of the magnetic resonance therapy. We support our approach by
some biological and histological data (both in vitro and in vivo) and, finally,
by some clinical data.
It is shown that electromagnetic fields affect dynamics of Davydov's solitons which provide charge transport processes in macromolecules during metabolism of the system. There is a resonant frequency of the field at which it can cause the transition of electrons from bound soliton states into delocalised states. Such decay of solitons reduces the effectiveness of charge transport, and, therefore, inhibits redox processes. Solitons radiate their own electromagnetic field of characteristic frequency determined by their average velocity. This self-radiated field leads to synchronization of soliton dynamics and charge transport processes, and is the source of the coherence in the system. Exposition of the system to the oscillating electromagnetic field of the frequency, which coincides with the eigen-frequency of solitons can enhance eigen-radiation of solitons, and, therefore, will enhance synchronization of charge transpor, stimulate the redox processes and increase coherence in the system. Electromagnetic oscillating field causes also ratchet phenomenon of solitons, i.e., drift of solitons in macromolecules in the presence of unbiased periodic field. Such additional drift enhances the charge transport processes. It is shown that temperature facilitates the ratchet drift. In particular, temperature fluctuations lead to the lowering of the critical value of the intensity and period of the field, above which the drift of solitons takes place. Moreover, there is a stochastic resonance in the soliton dynamics in external electromagnetic fields. This means, that there is some optimal temperature at which the drift of solitons is maximal.
In this paper, we analyze biological effects produced by magnetic fields in
order to elucidate the physical mechanisms, which can produce them. We show
that there is a chierarchy of such mechanisms and that the mutual interplay
between them can result in the synergetic outcome. In particular, we analyze
the biological effects of magnetic fields on soliton mediated charge transport
in the redox processes in living organisms. Such solitons are described by
nonlinear systems of equations and represent electrons that are self-trapped in
alpha-helical polypeptides due to the moderately strong electron-lattice
interaction. They represent a particular type of disssipativeless large
polarons in low-dimensional systems. We show that the effective mass of
solitons in the is different from the mass of free electrons, and that there is
a resonant effect of the magnetic fields on the dynamics of solitons, and,
hence, on charge transport that accompanies photosynthesis and respiration.
These effects can result in non-thermal resonant effects of magnetic fields on
redox processes in particular, and on the metabolism of the organism in
general. This can explain physical mechanisms of therapies based on applying
magnetic fields.
Over the past 25 years, organic field-effect transistors (OFETs) have witnessed impressive improvements in materials performance by 3-4 orders of magnitude, and many of the key materials discoveries have been published in Advanced Materials. This includes some of the most recent demonstrations of organic field-effect transistors with performance that clearly exceeds that of benchmark amorphous silicon-based devices. In this article, state-of-the-art in OFETs are reviewed in light of requirements for demanding future applications, in particular active-matrix addressing for flexible organic light-emitting diode (OLED) displays. An overview is provided over both small molecule and conjugated polymer materials for which field-effect mobilities exceeding > 1 cm(2) V(-1) s(-1) have been reported. Current understanding is also reviewed of their charge transport physics that allows reaching such unexpectedly high mobilities in these weakly van der Waals bonded and structurally comparatively disordered materials with a view towards understanding the potential for further improvement in performance in the future.
The soliton model of charge and energy transport in biological macromolecules is used to suggest one of the possible mechanisms for electromagnetic radiation influence on biological systems. The influence of the electromagnetic field (EMF) on molecular solitons is studied both analytically and numerically. Numerical simulations prove the stability of solitons for fields of large amplitude, and allow the study of emission of phonons. It is shown that in the spectra of biological effects of radiation there are two characteristic frequencies of EMFs, one of which is connected with the most intensive energy absorption and emission of sound waves by the soliton, and the other of which is connected with the soliton photodissociation into a delocalized state.
The parametrically driven, damped NLS equation is shown to describe the dynamics of small-amplitude breathers of the easy-plane ferromagnet and the long Josephson junction under the influence of the parametric pumping and dissipation. The soliton solutions are found exactly and stability problem for the dissipative case is reduced rigorously to the one for the undamped soliton.
We investigated the effect of extremely low-frequency electromagnetic field (ELF-EMF) with pulse trains exposure on lipid peroxidation, and, hence, oxidative stress in the rat liver tissue. The parameters that we measured were the levels of plasma alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase as well as plasma albumin, bilirubin, and total protein levels in 30 adult male Wistar rats exposed to ELF. We also determined the percentage of apoptotic and necrotic cells of the kidney extracts from the animals by flow cytometry method. Apoptotic cell death was further characterized by monitoring DNA degradation using gel electrophoresis. The results showed an increase in the levels of oxidative stress indicators, and the flow cytometric data suggested a possible relationship between the exposure to magnetic field and the cell death. We showed significantly lower necrotic cell percentages in experimental animals compared to either unexposed or sham control groups. However, DNA ladder analyses did not differentiate between the groups. Our results were discussed in relation to the response of biological systems to EMF.
The rate of ATP synthesis by creatine kinase extracted from V. xanthia venom was shown to depend on the magnetic field. The yield of ATP produced by enzymes with 24Mg2+ and 26Mg2+ ions in catalytic sites increases by 7-8% at 55 mT and then decreases at 80 mT. For enzyme with 25Mg2+ ion in a catalytic site, the ATP yield increases by 50% and 70% in the fields 55 and 80 mT, respectively. In the Earth field the rate of ATP synthesis by enzyme, in which Mg2+ ion has magnetic nucleus 25Mg, is 2.5 times higher than that by enzymes, in which Mg2+ ion has nonmagnetic, spinless nuclei 24Mg or 26Mg. Both magnetic field effect and magnetic isotope effect demonstrate that the ATP synthesis is an ion-radical process, affected by Zeeman interaction and hyperfine coupling in the intermediate ion-radical pair.
The previous observation with an electron microscope showed that extremely low frequency (ELF) pulsed magnetic field (PMF) (with the maximum intensity of 0.6-2.0 T, gradient of 10-100 T*M(-1), pulse width of 20-200 ms and frequency of 0.16-1.34 Hz) inhibited the growth of S-180 sarcoma in mice and enhanced the ability of immune cell's dissolving sarcoma cells. In this study, the DNA contents of nuclei were assayed by using Faulgen Staining method. With an electron microscope and cell stereoscopy technology it was observed that magnetic field affected the sarcoma cell 's metabolism, lowered its malignancy, and restrained its rapid and heteromorphic growth. The magnetic field enhanced the cellular immune ability and the reaction of lymphocytes and plasma. Since ELF pulsed magnetic fields can inhibit the growth of sarcomas and enhance the cellular immune ability, it is possible to use it as a new method to treat cancer.
Two independent laboratories have demonstrated that electromagnetic radiation at specific frequencies can cause a change in the efflux of calcium ions from brain tissue in vitro. In a local geomagnetic field (LGF) at a density of 38 microTesla (microT), 15- and 45-Hz electromagnetic signals (40 Vp-p/m in air) have been shown to induce a change in the efflux of calcium ions from the exposed tissues, whereas 1- and 30-Hz signals do not. We now show that the effective 15-Hz signal can be rendered ineffective when the LGF is reduced to 19 microT with Helmholtz coils. In addition, the ineffective 30-Hz signal becomes effective when the LGF is changed to +/- 25.3 microT or to +/- 76 microT. These results demonstrate that the net intensity of the LGF is an important variable. The results appear to describe a resonance-like relationship in which the frequency of the electromagnetic field that can induce a change in efflux is proportional to a product of LGF density and an index, 2n + 1, where n = 0,1. These phenomenological findings may provide a basis for evaluating the apparent lack of reproducibility of biological effects caused by low-intensity extremely-low-frequency (ELF) electromagnetic signals. In future investigations of this phenomenon, the LGF vector should be explicitly described. If the underlying mechanism involves a general property of tissue, then research conducted in the ambient electromagnetic environment (50/60 Hz) may be subjected to unnoticed and uncontrolled influences, depending on the density of the LGF.
The literature on biological effects of magnetic and electromagnetic fields commonly utilized in magnetic resonance imaging systems is surveyed here. After an introduction on the basic principles of magnetic resonance imaging and the electric and magnetic properties of biological tissues, the basic phenomena to understand the bio-effects are described in classical terms. Values of field strengths and frequencies commonly utilized in these diagnostic systems are reported in order to allow the integration of the specific literature on the bio-effects produced by magnetic resonance systems with the vast literature concerning the bio-effects produced by electromagnetic fields. This work gives an overview of the findings about the safety concerns of exposure to static magnetic fields, radio-frequency fields, and time varying magnetic field gradients, focusing primarily on the physics of the interactions between these electromagnetic fields and biological matter. The scientific literature is summarized, integrated, and critically analyzed with the help of authoritative reviews by recognized experts, international safety guidelines are also cited.
The stability of quasi-soliton excitations localized in a magnet near the region of excitation by a high-frequency external field has been studied within the framework of two models. They include nonlinear regions strongly excited by external pumping and regions of subsystems interacting with them, considered in the linear approximation. In the first model, the linear region is considered in the long-wavelength approximation for a system of finite length with distributed parameters. The second model considers a finite-dimensional system of coupled two linear and nonlinear magnetic moments under point pumping conditions. The similarity of the results of the two models is demonstrated. The existence of two regions of instability is shown: exponential and oscillatory, and their parameters are calculated. In both cases, the transition to the nonlinear regime of instability is accompanied by the formation of a train of nonlinear excitations of the type of “temporary” solitons of different nature. The nonlinear evolution of the instability leads to the transition of the system to a new stable state in the case of exponential instability, and the state of a stable limit cycle in the region of oscillatory instability.
The Davydov model for amide I propagation in hydrogen-bonded chains of proteins is revisited. The many similarities between the mixed quantum-classical dynamical equations and those that are derived from the full quantum Davydov model while applying the so-called D 2 ansatz are highlighted. The transition from a minimum energy localized amide I state to a fully delocalized state is shown to operate in four phases, one of which is abrupt and the last of which is a fast but smooth change from a very broad yet localized state to a completely delocalized one. Exploration of the dynamical phase space at zero temperature includes the well-known soliton propagation as well as double and triple discrete breathers, and dispersion of initially localized states. The uncertainties related to the question of the thermal stability of the Davydov soliton are illustrated. A solution to the seemingly endless problem of the short radiative lifetime of the amide I excitations is proposed.
Static soliton bound states in nonlinear systems are investigated analytically and numerically in the framework of the parametrically driven and damped nonlinear Schrödinger equation. We find that the ordinary differential equations, which determine bound soliton solutions, can be transformed into the form resembling the Schrödinger-like equations for eigenfunctions with fixed eigenvalues. We assume that a nonlinear part of the equations is close to the reflectionless potential well occurring in the scattering problem, associated with the integrable equations. We show that symmetric two-hump soliton solution is quite well described analytically by the three-soliton formula with the fixed soliton parameters, depending on the strength of parametric pumping and the dissipation constant.
The problem of electron transportation along a discrete deformable medium with linear on-site interactions in the Davydov approach is considered. It is found that the quasi-stationary state of the full equations of motion leads to a discrete nonlocal nonlinear Schrödinger (DNNLS) equation whose nonlocality is of the exponential type and depending on the on-site parameter. We use the variational approach to approximate discrete traveling wave solutions in the DNNLS equation. We find that the discrete solutions continued from the discrete nonlinear Schrödinger equation, corresponding to the vanishing of the on-site parameter, bifurcates in a critical on-site value. Additionally, a threshold in the velocity of propagation of the discrete structures is found.
This article offers an introduction to the vast area of experimental and theoretical studies of solitons. It is composed of two large parts. The first one provides a review of effectively one-dimensional (1D) settings. The body of theoretical and experimental results accumulated for 1D solitons is really large, the most essential among them being overviewed here. The second part of the article provides a transition to the realm of multidimensional solitons. These main parts are split into a number of sections, which clearly define particular settings and problems addressed by them. This article may be used by those who are interested in a reasonably short, but, nevertheless, sufficiently detailed introduction to the modern “soliton science”. It addresses, first, well-known “traditional” topics. In particular, these are the integrable Korteweg–de Vries, sine-Gordon, and nonlinear Schrödinger (NLS) equations in 1D, as well as the Kadomtsev–Petviashvili equations in 2D, and basic physical realizations of these classical equations. Then, several novel topics are addressed. Especially important between them are 2D and 3D solitons of the NLS type, which are stabilized against the collapse (catastrophic self-compression, which is the fundamental problem impeding the realization of multidimensional solitons) by the spin-orbit coupling or effects by quantum fluctuations in two-component Bose–Einstein condensates in ultracold atomic gases. This article introduces a part of the material which is represented in a systematic form in a new book, Multidimensional Solitons (B. A. Malomed, AIPP, 2022).
In the past few decades, the global investment made in nanotechnology research and development by both public and private sectors not only introduces a novel concept to understand the nature, but also brings next-generation nanomaterials and their various commercial applications in a variety of sectors including construction, electronics, flexible devices, food, agriculture, water, health care, catalysis, energy, medicine, etc. In this chapter, we are going to highlight few selected next-generation nanomaterials and their application in construction, electronic devices, water purification, medicines, and agriculture. Nevertheless, their increasing environmental exposure, which in turn creates a compelling need to understand their environmental fate and potential hazard, will also be discussed in this chapter.
We study the long-range electron and energy transfer mediated by a polaron on an α-helix polypeptide chain coupled to donor and acceptor molecules at opposite ends of the chain. We show that for specific parameters of the system, an electron initially located on the donor can tunnel onto the α helix, forming a polaron, which then travels to the other extremity of the polypeptide chain, where it is captured by the acceptor. We consider three families of couplings between the donor, the acceptor, and the chain and show that one of them can lead to a 90% efficiency of the electron transport from donor to acceptor. We also show that this process remains stable at physiological temperatures in the presence of thermal fluctuations in the system.
CONSPECTUS: Nanomedicine development aims to enhance the efficacy, accuracy, safety, and/or compliance of diagnosis and treatment of diseases by leveraging the unique properties of engineered nanomaterials. To this end, a multitude of organic and inorganic nanoparticles have been designed to facilitate drug delivery, sensing, and imaging, some of which are currently in clinical trials or have been approved by the Food and Drug Administration (FDA). In the process, the increasing knowledge in understanding how natural particulates, including cells, pathogens, and organelles, interact with body and cellular systems has spurred efforts to mimic their morphology and functions for developing new generations of nanomedicine formulations. In addition, the advances in bioengineering tools, bioconjugation chemistries, and bio-nanotechnologies have further enabled researchers to exploit these natural particulates for theranostic purposes. In this Account, we will discuss the recent progress in our lab on engineering bioinspired and biomimetic synthetic and cellular systems toward rational design of nanomedicine platforms for treating diabetes and cancer. Inspired by the structure and response mechanism of pancreatic β-cells, we synthesized a series of insulin granule-like vesicles that can respond to high blood or intestinal glucose levels for aiding in transdermal or oral insulin delivery, respectively. Then, to more closely mimic the multicompartmental architecture of β-cells, we further developed synthetic artificial cells with vesicle-in-vesicle superstructures which can sense blood glucose levels and dynamically release insulin via a membrane fusion process. Meanwhile, clues drawn from the traits of anaerobic bacteria that selectively invade and proliferate in solid tumors inspired the synthesis of a light-tuned hypoxia-responsive nanovesicle for implementing synergistic cancer therapy. In parallel, we also studied how autologous particulates could be recruited for developing advanced drug delivery systems. Through combination of genetic engineering and top-down cell engineering technologies, biomimetic nanomedicines derived from cytoplasmic membrane with programmed death 1 (PD-1) receptors expressed on surfaces were generated and employed for cancer immunotherapy. Based on our earlier study where aPD-L1 (antibodies against PD ligand 1)-conjugated platelets could release aPD-L1-bearing particles in situ and inhibit postsurgical tumor recurrence, we further genetically engineered megakaryocytes, the precursor cells of platelets, to express PD-1 receptors. In this way, platelets born with checkpoint blocking activity could be produced directly in vitro, avoiding post chemical modification processes while exerting similar therapeutic impact. As a further extension, by virtue of the bone marrow-homing ability of hematopoietic stem cells (HSCs), we recently conceived a cell-combination strategy by conjugating HSCs with platelets decorated with antibodies against PD1 (aPD-1) to suppress the growth and recurrence of leukemia. While we are still on the way of digging deep to understand and optimize bioinspired and biomimetic drug carriers, we expect that the strategies summarized in this Account would contribute to the development of advanced nanomedicines.
We have successfully developed easy-to-use and rapid immunosensor devices based on extended-gate type polymer field-effect transistors (PFETs). The designed PFET was operated under low-voltage conditions, being able to apply for the detection of proteins in water. As a consequence, label-free detection of glycoproteins was achieved by the extended-gate PFETs functionalized with monoclonal or polyclonal antibodies. We believe that PFET-based immunoassays will be an attractive platform for on-site monitoring devices in healthcare applications in the near future.
In this review we compile results cited in reliable journals that show a ratio for the use of pulsed electromagnetic fields (PEMF) in therapy, indeed. This is true especially for chronically inflamed joints. Furthermore, we try to link this therapeutic approach to the molecular background of chronic inflammation and arthritis. At first we start with the clinical outcome of PEMF therapy. Then, we look for possible triggers and an electromagnetic counterpart that is endogenously inherent in cell biology and in the tissues of interest. Finally, we want to investigate causal molecular and cellular mechanisms of possible PEMF actions. It shows that there are endogenous mechanisms, indeed, which can act as triggers for PEMF like the resting membrane potential as well as resonance mechanisms in charged moieties like membrane transporters. Especially voltage-gated calcium channels can be triggered. These may lead into specific signaling pathways and also may elicit nitric oxide as well as moderate radical reactions, which can ultimately lead to e.g. NFκB-like reactions. Concerted in the right way, these reactions can cause a kind of cell protection and ultimately lead to a dampening of inflammatory signals like interleukins.
Parametric excitation of autoresonant solutions of the nonlinear Schrodinger (NLS) equation by a chirped frequency traveling wave is discussed. Fully nonlinear theory of the process is developed based on Whitham's averaged variational principle and its predictions verified in numerical simulations. The weakly nonlinear limit of the theory is used to find the threshold on the amplitude of the driving wave for entering the autoresonant regime. It is shown that above the threshold, a flat (spatially independent) NLS solution can be fully converted into a traveling wave. A simplified, few spatial harmonics expansion approach is also developed for studying this nonlinear mode conversion process, allowing interpretation as autoresonant interaction within triads of spatial harmonics.
There is now a rich history to those experiments studying the stimulation of biological systems using extremely weak electrical and magnetic fields. In the following, we review this work, with particular emphasis on the experimental evidence in support of ion cyclotron resonance as the interaction mechanism underlying the observed effects. The number of compartmentalized groups studying electromagnetic effects in tissue is growing rapidly, and it is wise to limit the area we shall cover. Thus, we restrict ourselves solely to those observations involving time-varying fields, primarily in the ELF range. We will begin with a short review of ion cyclotron resonance.
Coherent excitations, as first proposed in 1968, can arise in the presence of nonlinear interactions if metabolic energy is supplied at a rate s above a critical so. Three types of excitations will be shown to exist: A excitation of a single mode; B excitation of a metastable highly polar state; C excitation of limit cycles or Lotka-Volterra oscillations in complex systems. They may have far reaching consequences on the dynamics of biological systems.
Externally applied radiation may, at certain frequencies and at certain stages of development, act as trigger to biological events. In this case a steplike dependence on the intensity is to be expected.
Relevant experimental evidence will be indicated.
The nonlinear mechanism of charge and energy transfer in biological macromolecules is discussed, which is based on the theory of molecular solitons. The main properties of solitons and their dynamics in discrete macromolecular systems are summarised and the corresponding biological consequences are analised. In particular, such consequences include the following. Charged solitons emit electromagnetic radiation, that can be a source for the informational exchange and via which intra- and inter-cellular signalling is possible. Such radiation is shown to result in the long-range interaction between electrosolitons, which leads to the synchronization of soliton dynamics, which can constitute one of the mechanisms of selfregulation in living systems. The soliton model based on the self-consistent description of the interaction between solitons, qualitatively describes main peculiarities of the charge transport that accompanies oxydative-phosphoryllation redox processes. The input of soliton states into the stimulated luminescence explains qualitatively and quantitatively the main properties of the delayed luminescence from biological systems.
The parametrically driven, damped NLS equation is numerically simulated in the neighbourhood of its exact soliton solution. We obtain the attractor chart on the control parameter plane in the domain of the soliton instability. Regions of the period-doubling and quasiperiodic transitions to chaos are found, and the existence of a critical point where the two scenaria meet, is demonstrated.
The dynamics of a bisoliton in three-dimensional strongly anisotropic crystals with identified soft one-dimensional chains, is studied in the presence of weak magnetic fields. Cyclotron mass and frequency of a bisoliton in a magnetic field are calculated.
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A study is made of the dynamics of a soliton in a strongly anisotropic three-dimensional crystal in the presence of a constant magnetic field that is parallel or perpendicular to the direction of distinguished one-dimensional chains in the crystal. It is shown that the motion of the soliton becomes finite in the plane perpendicular to the magnetic field.
It is shown in the framework of Quantum Field Theory how the dynamics of the phase transition from a gas to a condensed matter could be understood. The case of liquid water is discussed. It is investigated the role of water in the enzyme activity in biological matter.
The change in time of the state of intramolecular excitation in an one-dimensional molecular chain is investigated, where its deformability is taken into account. It is shown that the excitation which is accompanied by a local deformation of the chain, can move uniformly along the chain, the size of the region under excitation remaining constant. These excitations in one-dimensional molecular chains can be called particle-like excitons or solitary excitons.Es werden die zeitlichen Änderungen des intramolekularen Anregungszustandes in einer ein-dimensionalen molekularen Kette untersucht, wobei deren Deformierbarkeit berücksichtigt wird. Es wird gezeigt, daß die Anregung der Kette, die durch eine lokale Deformation begleitet ist, sich gleichförmig längs der Kette bewegen kann, wobei die Größe des angeregten Bereichs konstant bleibt. Diese Anregungen in ein-dimensionalen Molekülketten können partikel-ähnliche Exzitonen oder solitäre Exzitonen genannt werden.
The ground states of a quasiparticle electron, hole or exciton are investigated in a one-dimensional 1D molecular chain within the variational approach with account of quasiparticle interaction with acoustical and optical phonons. The ground state diagrams are obtained, which show the intervals of the values of dimensionless electron–phonon coupling constant, and nonadiabaticity parameter, Ž which correspond to the regimes of an almost free electron state, small polaron, and spontaneously localized large polaron or . soliton-like state, respectively. The creation of autolocalized states has a threshold with respect to the value of electron–phonon interaction. Such states correspond to the minimum of energy within some finite interval of the values of electron–phonon coupling constants, the critical values of which depend on the nonadiabaticity parameters of each phonon mode. It is shown that the presence of the second phonon mode enhances the stability of the autolocalized states as compared with the single mode case, and expanses the region of soliton existence in the one-mode nonadiabatic regime. q 2000 Elsevier Science S.A. All rights reserved.
Theories and experiments related to the localization of Amide-I (or CO stretching) vibrational energy in protein are surveyed. Such localization arises through interaction of the Amide-I mode with lattice distortion. Generalizations to charge transport and biological applications are also considered.
There is now a reasonable battery of evidence from a large number of laboratories, that exposure to extremely low frequency magnetic and electric fields (EMF) produces biological responses in animals. Many of the observed effects appear to be directly or indirectly associated with the neural or neuroendocrine systems. Such effects include increased neuronal excitability, chemical and hormonal changes in the nervous system, altered behavioral responses, some of which are related to sensing the presence of the field, and changes in endogenous biological rhythms. Bone growth and fracture repair clearly show evidence of effects by exposure to magnetic fields of sufficient intensity. Additional indices of general physiological status appear relatively unaffected by exposure, although effects have occasionally been described in reproduction and development and immune system function. A major focus of ongoing research in the laboratory is to determine whether the epidemiological-based suggested association between magnetic field exposure and risk of cancer can be supported in studies using animal models. Three major challenges exist for ongoing laboratory research: (1) knowledge about the mechanisms underlying observed bioeffects is incomplete, (2) understanding of the physical aspects of exposure and the dose that produce biological responses is not currently available, and (3) health consequences resulting from EMF exposure are primarily speculative. There is presently no clear and convincing evidence from animal or cellular studies that demonstrates deleterious effects of EMF. There are, however, some studies, though largely unreplicated, that are suggestive of potential health impacts. From the perspective of laboratory studies, this presentation will discuss biological responses to extremely low frequency magnetic field exposures
Cyclotron resonance in cell membrane: the theory of the mechanisms
- McLeod
On the mechanisms of wound healing by magnetic therapy: the working principle of therapeutic magnetic resonance
- Brizhik
Cyclotron resonance in membrane transport
- Liboff
Parametric autoresonant excitation of the nonlinear Schrödinger equation
- Friedl