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1.
Biofizika ; 61(2): 405-14, 2016.
Artigo em Russo | MEDLINE | ID: mdl-27192844

RESUMO

It is known that in quantum mechanics the act of observing the experiment can affect the experimental findings in some cases. In particular, it happens under the so-called Zeno effect. In this work it is shown that in contrast to the "standard" Zeno-effect where the act of observing a process reduces the probability of its reality, an inverse situation when a particle transmits through a potential barrier (a so-called barrier anti-Zeno effect) can be observed, the observation of the particle essentially increases the probability of its transmission through the barrier. The possibility of using the barrier anti-Zeno effect is discussed to explain paradoxical results of experiments on "cold nuclear fusion" observed in various systems including biological ones. (According to the observers who performed the observations, the energy generation, which could not be explained by any chemical processes, as well as the change in the isotope and even element composition of the studied object may occur in these systems.


Assuntos
Fenômenos Químicos , Modelos Teóricos , Fusão Nuclear , Probabilidade , Teoria Quântica , Temperatura
2.
Biofizika ; 60(3): 437-50, 2015.
Artigo em Russo | MEDLINE | ID: mdl-26349207

RESUMO

The analysis of conformationally stable (conformational conservative) tetrapeptides selected from protein structures deposited in PDBSelect data bank has been fulfilled. The subset contained 943 tetrapeptide amino acid sequences and there were merely five 3D protein segment representatives for each sequence. As a result, the conclusion has been drawn on the basis of DSSP annotation analysis that in the majority of cases (900 of 943) alpha-helical conformation is obvious. Different than alpha-helix, in particular, the left-handed polyproline II helical conformation was observed in 43 sequences. The physical and chemical properties of conformationally stable peptides taken from the appropriate sample were estimated by the average hydrophobicity/hydrophilicity of tetrapeptides. The results of calculations show that the "neutrality" towards hydrophobicity/hydrophilicity is representative of conformationally stable oligopeptides. It should be noted, that dispersion of hydrophobicity/hydrophilicity distribution is sufficiently lower than for the test subsets. Thus, the conformationally stable oligopeptides present a distinct group of local protein structures which are very close with respect to conformational and physicochemical properties. In accordance with our developed theory of specific long range interactions these peptides are the objects being quite useful for effective mutual molecular recognition.


Assuntos
Oligopeptídeos/química , Peptídeos/química , Bases de Dados de Proteínas , Interações Hidrofóbicas e Hidrofílicas , Modelos Moleculares , Estabilidade Proteica , Estrutura Secundária de Proteína , Termodinâmica
3.
Biofizika ; 60(4): 787-96, 2015.
Artigo em Russo | MEDLINE | ID: mdl-26394479

RESUMO

Coherent sources of electromagnetic waves in the terahertz frequency range are very promising for various applications, including biology and medicine. In this paper we propose a scheme of a compact terahertz source, in which terahertz radiation is generated due to effective interaction of electrons in a quantum well with an electromagnetic wave of a corrugated waveguide. We have shown that the generation of electromagnetic waves with a frequency of 1012 sec(-1) and an output power of up to 25. mW is possible in the proposed scheme.


Assuntos
Elétrons , Desenho de Equipamento , Radiação Terahertz , Impedância Elétrica , Teoria Quântica
4.
Biofizika ; 60(1): 173-5, 2015.
Artigo em Russo | MEDLINE | ID: mdl-25868357

RESUMO

During experimental studies of thermal regime of female mammary glands tissues the existence of periodic thermal waves was discovered. At the same time, the space-amplitude relief of such waves can mask the space-amplitude relief of the thermal profile, projected to the skin surface of mammary glands by tumor, hidden in the thickness of the gland. The phenomenon observed would be taken into account upon diagnosing pathological states of mammary glands.


Assuntos
Temperatura Alta , Glândulas Mamárias Humanas/fisiologia , Termogênese/fisiologia , Feminino , Humanos
5.
Biofizika ; 59(3): 533-40, 2014.
Artigo em Russo | MEDLINE | ID: mdl-25715597

RESUMO

Spheroid cell structures in the cell cultures have been described and are used for studying cell-cell and cell- matrix interactions. At the same time, spheroid cell structure participation in the repair and development of cancer in vivo remains unexplored. The aim of this study was to investigate the cellular composition of spherical structures and their functional significance in the repair of squamous epithelium in human papilloma virus-associated cervical pathology--chronic cervicitis and cervical intraepithelial neoplasia 1-3 degree, and also construct a mathematical model to explain the development and behavior of such spheroid cell structure.


Assuntos
Alphapapillomavirus , Modelos Biológicos , Infecções por Papillomavirus , Esferoides Celulares , Displasia do Colo do Útero , Neoplasias do Colo do Útero , Adulto , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Feminino , Humanos , Infecções por Papillomavirus/metabolismo , Infecções por Papillomavirus/patologia , Esferoides Celulares/metabolismo , Esferoides Celulares/patologia , Neoplasias do Colo do Útero/metabolismo , Neoplasias do Colo do Útero/patologia , Displasia do Colo do Útero/metabolismo , Displasia do Colo do Útero/patologia
6.
Biofizika ; 59(6): 1121-4, 2014.
Artigo em Russo | MEDLINE | ID: mdl-25715619

RESUMO

We propose a method for magnetic sorting of cell suspensions able to differentiate not only cells with single specific antigen on their surface, but also cells with a group of pre-defined antigens. Individually, each antigen of this group may be present on surfaces of non-selected cells. However, only the simultaneous presence of all given antigens on the cell surface means that such a cell should be separated. The method is of interest, for purification of cell suspensions from malignant cells, in particular, for purification of bone marrow material for autologous transplantation in leukemia.


Assuntos
Separação Celular , Campos Magnéticos , Modelos Teóricos , Neoplasias/patologia , Animais , Humanos
7.
Biofizika ; 58(6): 1032-7, 2013.
Artigo em Russo | MEDLINE | ID: mdl-25486762

RESUMO

When using nanodevices in oncology, it is necessary to provide the efficiency of the performance of these nanodevices simultaneously with their safety for an organism. These are conflicting objectives to some extent. Nevertheless, as shown in this work, an approach that helps to eliminate this contradiction is offered. For recognition and destruction of cancer cells in vivo it is suggested to use instead of one type simultaneously two types of introduced into an organism specialized nanodevices interacting with each other. Some of the nanodevices only recognize cancer cells, while the other ones, that can not recognize them, find cells being marked by nanodevices of the first type, and destroy them. This makes possible to increase the reliability of the cancer cell recognition process on the one side, and have the process of their destruction rather safe for an organism on the other side.


Assuntos
Nanotecnologia/instrumentação , Neoplasias/diagnóstico , Humanos , Neoplasias/terapia , Propriedades de Superfície
8.
Biofizika ; 58(6): 1069-73, 2013.
Artigo em Russo | MEDLINE | ID: mdl-25486767

RESUMO

In the work the arguments are presented in favor of the idea on the role of conformationally stable oligo-peptides in specific long-distance interactions in phenomena of molecular recognition during various biological processes. Original authors' and literature data are taken into account. The examples of conformationally stable short oligopeptides participation in alpha-helix and collagen type structures formation are given simultaneously with theoretical approaches. The conformationally stable oligopeptides obtained in the course of PDB bank analysis are discussed. The role of amino acids sequence in collagen helix formation is shown.


Assuntos
Modelos Moleculares , Peptídeos/química , Proteínas/química , Aminoácidos/química , Colágeno/química , Conformação Proteica , Estrutura Secundária de Proteína
9.
Biofizika ; 58(4): 645-51, 2013.
Artigo em Russo | MEDLINE | ID: mdl-24455884

RESUMO

A fundamentally new recognition method of bio-objects (in particular malignant cells) that escape the immune system supervision control is suggested. Recognition of such bio-objects should be carried out by the unified complex consisting of several molecular groups (for example, antibodies) bound to each other, each group identifies on a surface of this bio-object its target binding site. The choice of such targets is determined by a specific surface-antigen expression profiling. Thus the efficiency of recognition appears to be many times higher, than that in a situation when these molecular groups do not form a uniform complex and operate separately. The possibilities of destruction of such recognized cells are discussed.


Assuntos
Anticorpos/uso terapêutico , Antígenos de Neoplasias/imunologia , Modelos Imunológicos , Nanopartículas/uso terapêutico , Células Neoplásicas Circulantes/imunologia , Antígenos de Neoplasias/genética , Perfilação da Expressão Gênica , Humanos , Terapia de Alvo Molecular , Nanomedicina , Nanopartículas/química , Ligação Proteica
10.
Biofizika ; 57(6): 925-32, 2012.
Artigo em Russo | MEDLINE | ID: mdl-23272572

RESUMO

On the basis of the theory of specific long-range interaction between long molecules the approach has been elaborated for the "fast reading" of nucleotide sequences in sole DNA molecule. Firstly, a stretching force applies to the molecule that causes its unwinding from B-form to so called S-form. Then, a molecule disposes in a stretched state on the background. After this, the electrostatic potential is estimated in the space along the DNA filament. Information obtained is sufficient for the deduction of the nucleotide sequence in DNA. Another approach to the "reading" of information reduces to the measurement of the filament element deformation induced by electrostatic field from the electrode that stretches the filament by alternating current applied.


Assuntos
DNA/química , Eletricidade , Sequenciamento de Nucleotídeos em Larga Escala/instrumentação , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Fenômenos Biofísicos , Ligantes , Substâncias Macromoleculares , Modelos Teóricos
11.
Biofizika ; 57(6): 1062-7, 2012.
Artigo em Russo | MEDLINE | ID: mdl-23272589

RESUMO

It was shown that selective interactions between helical segments of macromolecules can realize in globular proteins in the segments characterized by the same periodicities of charge distribution i.e. between conformationally conservative oligopeptides. It was found that in the macromolecules of alpha-helical proteins conformationally conservative oligopeptides are disposed at a distance being characteristic of direct interactions. For representatives of many structural families of alpha-type proteins specific disposition of conformationally conservative segments is observed. This disposition is inherent to a particular structural family. Disposition of conformationally conservative segments is not related to homology of the amino acid sequence but reflects peculiarities of native 3D-architectures of protein globules.


Assuntos
Enzimas/química , Modelos Teóricos , Oligopeptídeos/química , Dobramento de Proteína , Estrutura Secundária de Proteína
12.
Biofizika ; 56(5): 863-7, 2011.
Artigo em Russo | MEDLINE | ID: mdl-22117443

RESUMO

The paper deals with some of already available nanotechnology-based methods for struggle against oncological diseases. We discuss the potentialities of essentially new approaches within which devices built inside diseased cells could operate their behaviour. Conceptually, using these approaches one can force such "controlled" cells to fight against tumours.


Assuntos
Nanomedicina/métodos , Nanoestruturas , Animais , Antineoplásicos/uso terapêutico , Humanos , Magnetismo , Nanoestruturas/uso terapêutico , Neoplasias/diagnóstico , Neoplasias/tratamento farmacológico
13.
Biofizika ; 55(1): 5-9, 2010.
Artigo em Russo | MEDLINE | ID: mdl-20184134

RESUMO

A method for direct experimental measurement of phases in X-ray diffraction analysis has been developed. The phases can be determined using a peculiar holographic filming (called here autoholography) in which the rays scattered on an object completely identical to the object under study but displaced, in a definite way, and turned in space relative to it serve as a reference beam. In principle, autoholography does not require any particularly good coherence of radiation since the reference bundle enables one to compensate to some extent for its absence. Therefore, X-rays used in X-ray diffraction analysis are well suited to autoholography.


Assuntos
Holografia , Modelos Teóricos , Difração de Raios X
14.
Biofizika ; 54(4): 742-7, 2009.
Artigo em Russo | MEDLINE | ID: mdl-19795798

RESUMO

The possibility of producing microparticles (10-1000 nm) suitable for the introduction into biological cells and tissues and producing the electrical field and electrical currents around them due to electrochemical and photoelectric processes is discussed. A number of phenomena related to antitumor immunity are discussed, and several hypotheses to explain them are invoked. Among them is the hypothesis that the antitumor activity of the immune system may be associated with some agents that are phagocytized by the cells of the macrophage series and promote their activation. Presumably, cell activation is triggered by the damage to phagosomes caused by the phagocytized agent. It is suggested to use for cell activation an artificial agent consisting of the above-mentioned electrically active microscopic particles. For example, it may consist of microscopic particles of semiconductor with zones of n- and p-type conductivity. Such particles act as microscopic photoelectric cells: when exposed to optical radiation, they generate a potential difference, which causes disruption and damage of phagosome membranes and results in the activation of immune cells.


Assuntos
Técnicas Eletroquímicas , Macrófagos/imunologia , Nanopartículas , Fagocitose/imunologia , Fagossomos/imunologia , Animais , Humanos , Camundongos
15.
Biofizika ; 54(1): 13-5, 2009.
Artigo em Russo | MEDLINE | ID: mdl-19334628

RESUMO

A relatively simple means is proposed for fastening a macromolecule such as DNA in a straight line on a dielectric support (which is essential for "fast reading" of sequences by physical methods). A randomly coiled molecule in solution can be caused to align with a "straightening electrode" under the support, as in a phase transition. Conditions are envisaged that should ensure processive settling without defects.


Assuntos
DNA/química , Técnicas Eletroquímicas/métodos , Transição de Fase , Eletrodos
16.
Biofizika ; 53(5): 910-2, 2008.
Artigo em Russo | MEDLINE | ID: mdl-18954023

RESUMO

The influence of imino acids on the thermodynamic characteristics of collagen type structures in various collagens has been analyzed. It was shown that the basic mechanism of entropy increase in the protein-water system consists in the alteration in the number of cooperative segments accompanying the increase in imino acids content, which can be observed during the melting of the fibrous macromolecule. The range of variation in the physical characteristics of cooperative units is determined, in particular, by the variability of hydrogen bond parameters. This is displayed in a broadening of the bands of NH-valence vibrations and the half-widths of transitions in post-denatured structures. Thus, the basic mechanism of the influence of imino acids on thermodynamic characteristics of collagens is related to the complex nature of the melting process. The dehydration-hydration mechanisms of native and denatured states become significantly different upon replacement of any amino acid by an imino acid.


Assuntos
Colágeno/química , Iminoácidos/química , Animais , Desidratação , Entropia , Humanos , Desnaturação Proteica , Vibração
17.
Biofizika ; 51(2): 382-4, 2006.
Artigo em Russo | MEDLINE | ID: mdl-16637349

RESUMO

A possible explanation for the occurrence of periodicity in the fine structure of histograms during nuclear decay is proposed. The hypothesis states that, even in the absence of polarization, when the spin distribution of decaying nuclei over directions is, on the average, isotropic, the fine structure of histograms should depend, due to fluctuations, on the angles at which the sample is observed. There fore, when the Earth after some period would make a full furn, the distribution of fluctuations would return to the initial one, and, correspondingly, the fine structure of the histograms would repeat.


Assuntos
Planeta Terra , Modelos Teóricos , Radioatividade , Física Nuclear/métodos
18.
Biofizika ; 48(5): 937-9, 2003.
Artigo em Russo | MEDLINE | ID: mdl-14582423

RESUMO

Equations for the potentials of interactions between macromolecules of different shapes incorporated into smectic liquid crystals are presented. In addition to accurate equations, simple formula for estimation are given.


Assuntos
Estrutura Molecular , Cristalização
19.
Biofizika ; 48(3): 389-99, 2003.
Artigo em Russo | MEDLINE | ID: mdl-12815847

RESUMO

The results of theoretical calculations of interactions between macromolecules dissolved in ordered media such as liquid crystals and biological membranes (lipid bilayers) are reviewed. Expressions for the potentials of interactions between macromolecules of different shape incorporated into nematic liquid crystals, thin films, and lipid mono- and bilayers were derived. In addition to exact expressions, simple evaluating formulae are given. The two-dimensional "gas" of macromolecules swimming on the membrane was considered, and the expression of state for this "gas" was derived. It was shown that in the "gas", phase transitions accompanied by the formation of two-dimensional clusters may occur. The estimates of critical density at which these transitions occur are given.


Assuntos
Bicamadas Lipídicas , Modelos Químicos
20.
Biofizika ; 48(6): 1147-50, 2003.
Artigo em Russo | MEDLINE | ID: mdl-14714532

RESUMO

The fundamental gnoseological question that is always present in a basic science is: Can this science adequately predict the future? In classical mechanics, we deal in many cases with dynamic chaos; therefore, this prediction is most often impossible. In the quantum theory, the dynamic chaos associated with the disturbances of initial conditions is formally absent. Nevertheless, as it was shown in this work, there are other reasons that directly relate to what is called the paradoxes of formal logic, which, in the case of quantum theory, too, do not enable one to precisely determine what will happen in the future.


Assuntos
Teoria Quântica , Ciência
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