9,100 results match your criteria Biofizika[Journal]


[On Atomic Nuclear Fusion Processes at Low-Temperatures. An Enhancement of the Probability of Transition through a Potential Barrier Due to the So-Called Barrier Anti-Zeno Effect].

Authors:
V A Namiot

Biofizika 2016 Mar-Apr;61(2):405-14

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. Read More

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[An Iterative Continuous-Event Model of the Population Outbreak of Phytophagous Hemiptera].

Biofizika 2016 Mar-Apr;61(2):395-404

Based on the analysis of changes in the local density of the insect within the family Psillidae in Australia we have developed a model for a scenario of a dramatic increase in the number of jumping plant lice at the expense of primary and secondary Encyrtidae parasitoid microwasps. A phenomenological model describes on a case by case basis the efficiency of reproduction in several ranges of population conditions. We have proposed a continuous-event structure, where the rate of a decrease of the number of psyllid generations is uneven at different stages of ontogenesis of the insect with an incomplete metamorphosis. Read More

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[Providing the Optimal Insolation of a Photobiological Architectural Shell for Microalgae Cultivation].

Biofizika 2016 Mar-Apr;61(2):386-94

Translucent architectural shells with microalgae are considered as an element of local photobiological treatment facilities integrated in the urban environment. A mathematical microalgae growth model for the prediction of insolation and temperature behaviour in the medium during microalgae cultivation under dynamically fluctuating natural lighting is presented. The task of optimizing the parameters of photobiological architectural shell with respect to temperature and insolation is set. Read More

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[Neurodynamic Bases of Imitation Learning and Episodic Memory].

Authors:
V D Tsukerman

Biofizika 2016 Mar-Apr;61(2):374-85

In this review, three essentially important processes in development of cognitive behavior are considered: knowledge of a spatial environment by means of physical activity, coding and a call of an existential context of episodic memory and imitation learning based on the mirror neural mechanism. The data show that the parietal and frontal system of learning by imitation, allows the developing organism to seize skills of management and motive synergies in perisomatic space, to understand intentions and the purposes of observed actions of other individuals. At the same time a widely distributed parietal and frontal and entorhinal-hippocampal system mediates spatial knowledge and the solution of the navigation tasks important for creation of an existential context of episodic memory. Read More

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[Some Approaches to Activation of Antitumor Resistance Mechanisms and Functional Analogs in Categories of Synergetics].

Biofizika 2016 Mar-Apr;61(2):359-73

This paper briefly reviews the ways of activation of the antitumor resistance mechanisms developed on the basis of the concept of the periodic system of general nonspecific adaptational reactions of the body. The principles of the formation of effective influences by electromagnetic radiation using biologically active substances are described. A comparison of the criteria and conceptions of the theory of adaptational reactions to some concepts and categories of synergetics is made. Read More

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June 2016
9 Reads

[Mechanism of Formation of Cardiac Arrhythmia Due to Pathological Distribution of Myocardium Conductivity].

Biofizika 2016 Mar-Apr;61(2):352-8

Two mechanisms responsible for the emergence of arrhythmia are known: a change of part of the cells to a self-oscillatory mode and generation of circulating waves. In this paper, we investigate the generation mechanism of the circulating waves using the unidirectional block. One of the variants of its realization is a narrow gap between two non-conducting regions. Read More

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[Nitric Oxide in Modulation of Crystallogenic Propeties of Biological Fluid].

Biofizika 2016 Mar-Apr;61(2):345-51

The aim of this work was a comparative analysis of the influence of different NO forms on dehydration structurization of human blood serum. Blood specimens from 15 healthy people were treated by NO-containing gas flow (800 and 80 ppm) generated with the "Plazon" unit, experimental NO-generator (20, 50, 75 and 100 ppm) and by water solution of thiol-containing dinitrosyl iron complexes (3 mM/L). The influence of blood sodium on blood serum crystallization in original and NO-treated blood specimens was estimated. Read More

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[Changes in Kinetics of Chemiluminescence of Plasma as a Measure of Systemic Oxidative Stress in Humans].

Biofizika 2016 Mar-Apr;61(2):337-44

Oxidative stress is a pathogenetic factor of many diseases. The control of its level is important for early diagnosis and therapy adjustment. In this work, antioxidant status was estimated in blood plasma. Read More

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June 2016
6 Reads

[The Role of Membrane-Bound Heat Shock Proteins Hsp90 in Migration of Tumor Cells in vitro and Involvement of Cell Surface Heparan Sulfate Proteoglycans in Protein Binding to Plasma Membrane].

Biofizika 2016 Mar-Apr;61(2):328-36

Heat shock protein Hsp90, detected in the extracellular space and on the membrane of cells, plays an important role in cell motility, migration, invasion and metastasis of tumor cells. At present, the functional role and molecular mechanisms of Hsp90 binding to plasma membrane are not elucidated. Using isoform-specific antibodies against Hsp90, Hsp9α and Hsp90β, we showed that membrane-bound Hsp90α and Hsp90β play a significant role in migration of human fibrosarcoma (HT1080) and glioblastoma (A-172) cells in vitro. Read More

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[The Role of ABCG2 Protein in Maintenance of Viability and Proliferative Activity of Bone Marrow Mesenchymal Stem Cells Under Hypoxic Conditions].

Biofizika 2016 Mar-Apr;61(2):321-7

It has been shown that hypoxia (5% 02) and fibroblast growth factor bFGF reduce the doubling time of bone marrow mesenchymal stem cells under their cultivation in vitro that indicates an increase in cell culture proliferation. It has been found out that low concentrations of O2 and factor bFGF added to the cell culture medium increase an expression of abcg2 gene and its gene protein, ABCG2 transport gene, in mesenchymal stem cells. These events potentiate the effects of hypoxia observed in mesenchymal stem cells. Read More

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[Influence of Storage Temperature and Cryopreservation Conditions on the Extent of Human Sperm DNA Fragmentation].

Biofizika 2016 Mar-Apr;61(2):316-20

With the direct labeling procedure for detecting DNA fragmentation we explored the influence of the different storage temperature conditions as well as different methods of cryopreservation on the structure of DNA organization in the human sperm. 19 sperm samples obtained from healthy men with normozoospermia (according to the criteria of the World Health Organization) were used for investigation. A significant increase of human sperm DNA-fragmentation was observed after 8 hours of incubation at +39 degrees C (by 76. Read More

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June 2016
1 Read

[The Nonlinear Effect of the Composite Influence of Red and Blue Light on Bacteria Escherichia coli Viability].

Biofizika 2016 Mar-Apr;61(2):310-5

A non-linear dependence of the inhibition of E. coli cells is found when irradiated simultaneously with the blue and red regions of the spectrum at a power density of 100 mW/cm2. Such dependence is explained by the assumption of a cascade two-photon absorption of light by DNA molecules with an intermediate resonance at cellular chromophores, causing excitation and subsequent DNA damage similar to damage when exposed to UV radiation. Read More

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[Generation of Superoxide Radicals by Complex III in Heart Mitochondria and Antioxidant Effect of Dinitrosyl Iron Complexes at Different Partial Pressure of Oxygen].

Biofizika 2016 Mar-Apr;61(2):304-9

The EPR spin-trapping technique and EPR-oximetry were used to study generation of superoxide radicals in heart mitochondria isolated from Wistar rats under conditions of variable oxygen concentration. Lithium phthalocyanine and TEMPONE-15N-D16 were chosen to determine oxygen content in a gas-permeable capillary tube containing mitochondria. TIRON was used as a spin trap. Read More

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[Gelation in Low Concentrated Solutions of Cholesterol and Ergosterol].

Biofizika 2016 Mar-Apr;61(2):297-303

The molecular dynamics method has been applied to investigate the conformational behavior of biologically important chiral molecules of cholesterol and ergosterol. The formation of strings in the solution of cholesterol in methanol and the lack of strings in solutions of ergosterol in methanol has been experimentally detected. It was shown that the intermolecular dynamics in the molecule has a significant impact on the potential of structure formation. Read More

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[Forced Oscillations of DNA Bases].

Biofizika 2016 Mar-Apr;61(2):286-96

This paper presents the results of the studying of forced angular oscillations of the DNA bases with the help of the mathematical model consisting of two coupled nonlinear differential equations that take into account the effects of dissipation and the influence of an external periodic field. The calculation results are illustrated for sequence of gene encoding interferon alpha 17 (IFNA 17). Read More

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[Determination of the Minimal Fragment of the Poliovirus IRES Necessary for the Formation of a Specific Complex with the Human Glycyl-tRNA Synthetase].

Biofizika 2016 Mar-Apr;61(2):277-85

Aminoacyl-tRNA synthetases are an ancient enzyme family that specifically charge a tRNA molecule with a cognate amino acid required for protein synthesis. Glycyl-tRNA synthetase is one of the most interesting aminoacyl-tRNA synthetases due to its structure variability and functional features in the different organisms. It was shown recently that human glycyl-tRNA synthetase is a regulator of translational initiation of poliovirus mRNA. Read More

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June 2016
1 Read

[Interaction of Dystamycin Dimeric Analog with Poly(dA) x poly(dT), Poly[d(A-T)] x poly[d(A-T)] and Duplex O23 at Origin of Replication of the Herpes Simplex Virus].

Biofizika 2016 Mar-Apr;61(2):270-6

The binding of distamycin dimeric analog (Pt-bis-Dst) to poly[d(A-T)] x poly[d(A-T)1, poly(dA) x poly(dT) and duplex O23 with the sequence 5'-GCCAATATATATATATTATTAGG-3' which is present at the origin of replication of herpes simplex virus OriS is investigated with the use of UV and CD spectroscopy. The distinction of the synthetic polyamide from a natural antibiotic lies in the fact that in the synthetic polyamide there are two distamycin moieties bound via a glycine cis-diamino platinum group. It was shown that the binding of Pt-bis-Dst to poly[d(A-T)] x poly[d(A-T)] and poly(dA) x poly(dT) reaches saturation if one molecule of the ligand occurs at approximately every 8 bp. Read More

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June 2016
5 Reads

[Analysis of Conformational Features of Watson-Crick Duplex Fragments by Molecular Mechanics and Quantum Mechanics Methods].

Biofizika 2016 Mar-Apr;61(2):259-69

It is generally accepted that the important characteristic features of the Watson-Crick duplex originate from the molecular structure of its subunits. However, it still remains to elucidate what properties of each subunit are responsible for the significant characteristic features of the DNA structure. The computations of desoxydinucleoside monophosphates complexes with Na-ions using density functional theory revealed a pivotal role of DNA conformational properties of single-chain minimal fragments in the development of unique features of the Watson-Crick duplex. Read More

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[On a Possible Mechanism of the Effect of Microwave Radiation on Biological Macromolecules].

Biofizika 2016 Mar-Apr;61(2):255-8

A model describing the process of dissociation of hydrogen bonding in water clusters when irradiated by electromagnetic field in the microwave range is suggested. The model is also applicable for the case of rupture of the covalent bond of the water molecule cluster. If the energy absorption occurs at the interface of water and polymer clusters (e. Read More

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[Structure and Activity of Fungal Lipases in Bile Salt Solutions].

Biofizika 2016 Mar-Apr;61(2):247-54

The changes in structure and catalytic properties of fungal lipases (Candida rugosa, Rhizomucor miehei, Mucor javanicus) were investigated in micellar solutions of bile salts that differ in hydrophilic-lypophilic balance and reaction medium properties. The methods of circular dichroism and tryptophan fluorescence were applied to estimate the changes in peptide structure within complexes with bile salt micelles. Bile salts do not exert a significant influence on the structure of the enzymes under study: in Rh. Read More

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June 2016
3 Reads

[Magnetic Magnesium Isotope Accelerates ATP Hydrolysis Catalyzed by Myosin].

Biofizika 2016 Mar-Apr;61(2):239-46

In this paper, we present the results of experimental studies on the influence of different magnesium isotopes, the magnetic 25Mg and nonmagnetic 24Mg and 26Mg on ATP activity of the isolated myosin subfragment-1. The reaction rate in the presence of magetic 25Mg isotope turned out to be 2.0-2. Read More

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June 2016
2 Reads

[Similarity of Spectral Profiles with Individual Fluorescence Lifetime of Tryptophan in Proteins of Different Structure].

Biofizika 2016 Mar-Apr;61(2):231-8

This work presents the results of the analysis of the fluorescence lifetime of tryptophan in three proteins: human serum albumin, bovine serum albumin and bacterial luciferase, containing 1, 2 and 7 tryptophan residues, respectively. It was shown that for all proteins fluorescence decay can be fitted by three lifetimes: τ1 = 6-7 ns, τ2 = -2,0-2,3 ns and τ3 ≤ 0,1 ns (the native state) and τ1 = 4,4-4,6 ns, τ2 = 1,7-1,8 ns and τ3 ≤ 0,1 ns (the denaturated state). It was found that spectral profiles with individual protein fluorescence lifetime have similar peak wavelength and identical half-width of the spectrum as in the native state (λ(max)τ1 = 342 nm, λ(max)τ2 = 328 nm and λ(max)τ3 = 3i5 nm), and in the denaturated state (λ(max)τ1 = 350 nm, λ(max)τ2 = 343 nm and λ(max)τ3 = 317 nm). Read More

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[Protein Folding and Stability in the Presence of Osmolytes].

Biofizika 2016 Mar-Apr;61(2):222-30

Osmolytes are molecules with the function among others to align hydrostatic pressure between intracellular and extracellular spaces. Accumulation of osmolytes occurs in the cell in response to stress caused by pressure change, change in temperature, pH, and concentration of inorganic salts. Osmolytes can prevent native proteins denaturation and promote folding of unfolding proteins. Read More

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[Dynamics of Irreversible Evaporation of a Water-Protein Droplet and a Problem of Structural and Dynamical Experiments with Single Molecules].

Biofizika 2016 Mar-Apr;61(2):213-21

We discuss the effect of isothermal and adiabatic evaporation of water on the state of a water-protein droplet. The discussed problem is of current importance due to development of techniques to perform single molecule experiments using free electron lasers. In such structure-dynamic experiments the delivery of a sample into the X-ray beam is performed using the microdroplet injector. Read More

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[Evaluation of Gene Expression of Hexokinases in Colorectal Cancer with the Use of Bioinformatics Methods].

Biofizika 2015 Nov-Dec;60(6):1050-6

One of the hallmarks of cancer is the change of energy metabolism, mainly activation of glycolysis that occurs even at early stages of tumorigenesis. The glycolysis activation can be caused by overexpression of hexokinases, primarily HK1 and HK2. Colorectal cancer, which takes the third place in the cancer morbidity and mortality rates worldwide, is believed to be accompanied with overexpression of HK2, which is . Read More

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April 2016
18 Reads

[Method of Entirely Parallel Differential Evolution for Model Adaptation in Systems Biology].

Biofizika 2015 Nov-Dec;60(6):1219-20

We developed a method of entirely parallel differential evolution for identification of unknown parameters of mathematical models by minimization of the objective function that describes the discrepancy of the model solution and the experimental data. The method is implemented in the free and open source software available on the Internet. The method demonstrated a good performance comparable to the top three methods from CEC-2014 and was successfully applied to several biological problems. Read More

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[The Effect of the Chromophore Charge on the Efficiency of Incorporation of Fluorescently-labeled Nucleotides in Matrix Synthesis by Taq DNA Polymerase].

Biofizika 2015 Nov-Dec;60(6):1216-8

In order to study the effect of an electrical charge of the chromophore, on the efficiency of incorporation of fluorescently-labeled nucleotides into DNA during PCR, three fluorescently-labeled dUPT, one of which with electroneutral and other two with positively and negatively charged dyes (Cy5 analogs), were synthesized. It is shown that dUPT, labeled with electroneutral Cy 5 analog, is most effectively incorporated into DNA when Tag polymerase is used for PCR. Read More

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April 2016
3 Reads

[Period-tripling in Multiscale Physical and Biological Events].

Biofizika 2015 Nov-Dec;60(6):1208-15

A recent paper by S.J. Puetz et al. Read More

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[Search for the Influence Contributing to the Study of an Underlying Cause of Water Cluster Structure].

Biofizika 2015 Nov-Dec;60(6):1203-7

One of the theoretical underlying causes of the formation of water cluster structure is based on nuclear ortho/para spin isomerism of H2O molecules. This theory was so convincing that motivated the search for the experiments on theory validation. The long-term increase in the number of models of the supramolecular water structure did not lead to a reliable result yet, despite numerous efforts of large research teams. Read More

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[Methods for Reducing Laser Speckles to Achieve Even Illumination of the Microscope Field of View in Biophysical Studies].

Biofizika 2015 Nov-Dec;60(6):1198-202

The aim of this work was to compare different speckle reduction techniques. It was shown that the use of devices based on liquid crystals only leads to partial reduction of speckle contrast. In quantitative luminescent microscopy an application of the mechanical devices when a laser beam is spread within the field of view turned out to be more efficient. Read More

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April 2016
2 Reads

[On Two Opposing (Bio)surfaces as Comprehended in Terms of an Extension of the Coulomb-Amontons Law of Friction, with Its Virtual Usefulness for Biotribology in Nanoscale].

Biofizika 2015 Nov-Dec;60(6):1191-7

An extension of the Coulomb-Amontons law is proposed in terms of an interaction-detail involving renormalization (simplified) n-th level scheme. The coefficient of friction is obtained in a general exponential (nonlinear) form, characteristic of virtually infinite (or, many body) level of the interaction map. Yet, its application for a hydration repulsion bilayered system, prone to facilitated lubrication, is taken as linearly confined, albeit with an inclusion of a decisive repelling force/pressure factor. Read More

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[Studying the Persistence of Blood Flow Oscillations in Rat Kidneys].

Biofizika 2015 Nov-Dec;60(6):1186-90

This work was designed to study the nonlinear dynamics of fluctuations in renal blood flow of rats under basal conditions and in the perturbed state. An intramuscular injection of aspirin in 0.9% physiological saline (0. Read More

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April 2016
2 Reads

[Mathematical Modelling of the Dependence of the Performance of the Left Ventricle of the Heart on Preload and Afterload].

Biofizika 2015 Nov-Dec;60(6):1180-5

The results of the numerical simulation of the end-diastolic, end-systolic and stroke volumes of the left ventricle of the heart are presented. The simulation was based on a published simple kinetic model of cardiac muscle and approximation of the ventricle geometry with thick-wall cylinder where the fibre orientation varied linearly from sub-epicardium towards sub-endocardium. Blood flow was modelled with a liner compartment model. Read More

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April 2016
1 Read

[Mathematical Modeling of the Stretching-induced Elongation of an Embryonic Epithelium Layer in the Absence of External Load].

Biofizika 2015 Nov-Dec;60(6):1174-9

A clue to understanding the deformation of a plane embryonic epithelium layer unloaded after a short time uniaxial stretch and fixation in a stretched state over different time periods is found. The first steps in the understanding of this process come from the knowledge about the uniform stretching of the tissue fragment (explantate) with the subsequent stretching at a fixed length. In this study we used the earlier developed continuum model that describes the stress-strain state of the epithelial tissue taking into account the parameters that characterize the shape of the cells and their stress state, and also the active stresses they exert when interact with one another. Read More

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[Effect of Hepatic P450 2e1 Activity Modulation on the Toxicity and Carcinogenicity of Diethylnitrosamine in Mice].

Biofizika 2015 Nov-Dec;60(6):1166-73

In this paper, the biological effects of diethylnitrosamine have been studied under controlled conditions of its metabolism in mice of different ages. The data presented indicate that diethylnitrosamine in a non-metabolized form exerts general toxic and hepatocarcinogenic effects while alkylating agents of this compound produce toxic liver injury. To our knowledge, the data presented impel to revise the general notion of an exceptional role of mutagenic activation in the carcinogenic effect of chemicals. Read More

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[Anti-Tumour Activity of Dinitrosyl Iron Complex with Glutathione and S-Nitrosoglutathione Preparations: Comparative Studies].

Biofizika 2015 Nov-Dec;60(6):1157-65

The anti-tumor activity of the binuclear form of dinitrosyl iron complexes with glutathione against Lewis lung carcinoma, found earlier upon intraperitoneal administration of the complexes, was also observed when this preparation was injected subcutaneously. A 100 μM/kg subcutaneous dose of the complex being used daily (as calculated per one iron atom in binuclear dinitrosyl iron complexes) for 10 or 15 days, inhibited the tumor growth by 43%. The effect was observed during the first two weeks after tumor transplantation. Read More

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April 2016
2 Reads

[Cytoprotective Effects of Phytoestrogen Genistein against Cancer Cells].

Biofizika 2015 Nov-Dec;60(6):1151-6

In this paper we study the effect of synthetic isoflavonoid genistein against cancer HeLa cells, which contain estrogen receptors alpha but not beta, with the aim to determine the cytotoxic or cytoprotective effect of genistein. It is shown that the half maximal inhibitory concentration (IC50) value of genistein (0.2 mM) for the growth inhibition of HeLa cells is at least ten times higher than that one of tamoxifen and cisplatin--drugs, used in cervical cancer treatment. Read More

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[Inhibition of NF-kB Activation Decreases Resistance in Acute Myeloid Leukemia Cells to TRAIL-induced Apoptosis in Multicellular Aggregates].

Biofizika 2015 Nov-Dec;60(6):1146-50

Suppression of resistance in acute myeloid leukemia cells to TRAIL-induced apoptosis in multicellular aggregates, was studied using small molecule inhibitors of the activation of the transcription factor NF-kB - NF-k9 Activation Inhibitor IV and JSH-23 at non-toxic concentrations. NF-kB Activation Inhibitor IV and JSH-23 reduced resistance in the acute myeloid leukemia cells in multicellular aggregates to cytotoxic action of recombinant protein izTRAIL. It is shown that the use of these inhibitors decreased the phosphorylation of the RelA (p65) as a main marker activation of the transcription factor NF-kB. Read More

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[Interaction of Membrane and Calcium Oscillators in Cardiac Pacemaker Cells: Mathematical Modeling].

Biofizika 2015 Nov-Dec;60(6):1138-45

An integrative model of the calcium dynamics in cardiac pacemaker cells is developed taking into account a synergetic effect of the interaction between an outer membrane oscillator and an intracellular calcium oscillator ("membrane and Ca(2+)-clock"). The main feature of the model is a description of the stochastic dynamics of Ca2+ release units within the electron-conformational mechanism of the functioning of ryanodine-sensitive calcium channels. It is shown that interaction of two cellular oscillators provides a stable action potential generation in the cardiac pacemaker cells even in the case of the stochastic Ca2+ dynamics. Read More

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April 2016
4 Reads

[Biophysical Model of Contractile Activity of Muscle Cells].

Biofizika 2015 Nov-Dec;60(6):1132-7

Muscle cells have the specific structure, the advanced cytoskeleton, which takes most of cell volume and forms a contractile apparatus. On the basis of the equations of continuum mechanics we proposed a mathematical model of the biomechanical behavior of cells as a whole, and it was modified to describe the contractile activity in muscle cells as an elastic rod. The model takes into account the result of transduction of external influences, namely the development of internal deformation, and allows for estimation of mobility and/or tension developed in muscle cells in the case of change in external influence. Read More

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[Degradation of Mitochondria to Lipofuscin upon Heating and Illumination].

Biofizika 2015 Nov-Dec;60(6):1125-31

In the present work, it has been shown that the isolated mitochondria can undergo transformation to lipofuscin granules without any additional factors (oxygen saturation, prooxidants). The process occurs spontaneously and slowly at low temperature, and rapidly--by heating (thermo-lipofuscin) or under UV irradiation (photo-lipofuscin). The main contribution to the formation of mitochondrial lipofuscin comes from denatured proteins. Read More

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[Influence of Microbial Metabolites of Phenolic Nature on the Activity of Mitochondrial Enzymes].

Biofizika 2015 Nov-Dec;60(6):1118-24

The aim of this work was to study the effect of microbial metabolites of phenolic nature on the activity of enzymes of the tricarboxylic acid cycle in isolated mitochondria, and determine metabolites of the tricarboxylic acid cycle as potential biomarkers of mitochondrial dysfunction in the blood of patients with sepsis. It is shown that microbial metabolites of phenolic nature have an inhibitory effect on the activity of dehydrogenases, determined by the reduction of dichlorophenolindophenol and nitroblue tetrazolium in liver mitochondria and liver homogenates. This effect is more pronounced in oxidation of the NAD-dependent substrates than succinate oxidation, and at lower concentrations of microbial metabolites than inhibition of respiration. Read More

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April 2016
1 Read

[Protomitohondria of Liver Cells, Their Similarities and Differences between Mitochondria].

Biofizika 2015 Nov-Dec;60(6):1109-17

In this paper we continue the study of a number of properties of protomitochondria--small young mitochondrial organelles in the animal cells. Protomitochondria were obtained by filtration of total suspension of mitochondria of rat liver through Millipore filters. Protomitochondria contain an active respiratory chain as evidenced by the high rate of oxygen consumption during succinate and NADH oxidation. Read More

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April 2016
4 Reads

[Effects of Light Near-Infrared Radiation on Rats Assessed by Succinate Dehydrogenase Activity in Lymphocytes on Blood Smears].

Biofizika 2015 Nov-Dec;60(6):1104-8

Biological effects of light near infrared radiation (850 nm), with modulation acoustic frequency of 101 Hz, was studied. The study was conducted on rats, the effect was recorded by succinate dehydrogenase activity in lymphocytes on the blood smear after administration of the activating dose of adrenaline, which simulates the state of the organism in the early stages of the pathogenic effects (stress). A pronounced regulating effect of infrared radiation on the activity of succinate dehydrogenase in animals activated by adrenaline was shown. Read More

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[Influence of Low-Frequency Electromagnetic Field on DNA Molecules in Water Solutions].

Biofizika 2015 Nov-Dec;60(6):1099-103

It is shown that the amplicons of hepatitis virus DNA (hepatitis B virus, hepatitis C virus) are capable of inducing radiation after an exposure to electromagnetic fields in the frequency range from 3 to 30 Hz and the field strength, 24-40 A/m, registered by means of a chemiluminescence method. The most effect of the electromagnetic field on water solutions of the amplicons of hepatitis virus DNA occurs at the frequency of 9 Hz, the change in the hydration shell of DNA amplicons is observed. It is suggested that the change in the hydration shell of DNA amplicons exposed to the low-frequency electromagnetic field leads to restoration of hydrogen bonding, stitchings formation and DNA repair as a whole. Read More

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[Comparative Efficiency of Algorithms Based on Support Vector Machines for Regression].

Biofizika 2015 Nov-Dec;60(6):1085-98

Methods of construction of support vector machines do not require additional a priori information and can be used to process large scale data set. It is especially important for various problems in computational biology. The main set of algorithms of support vector machines for regression is presented. Read More

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[Assessment of Binding Properties of Actinomycin and Its Derivatives with DNA Molecule Using Molecular Dynamics Simulation Method].

Biofizika 2015 Nov-Dec;60(6):1077-84

Molecular dynamics simulation method was used to assess an influence of actinomycins (antibiotics used in chemotherapy for treatment of some oncology diseases) on DNA fragment elasticity. Also the efficiency of binding of actinomycin to DNA fragment was estimated. Energetic contributions of different substitutions of hydroxyl and amino-group to the phenoxazine ring of actinomycin were studied to analyze dynamic behavior and stability of antibiotic-DNA fragment complexes. Read More

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April 2016
4 Reads

[Prediction of Protein Conformational Mobility and Evaluation of Its Reliability Using Small-Angle X-ray Scattering].

Biofizika 2015 Nov-Dec;60(6):1069-76

The "coarse-grained" model of protein conformational mobility is presented. We compared the trajectories of conformational motions predicted for five proteins using this model with the motion obtained by the method of the "nearest neighbor", based on small-angle X-ray scattering data. It is shown that for all studied proteins the sequence of conformations calculated on the basis of "coarse-grained" model and on the basis of the "nearest neighbor", coincides well, although there are exceptions. Read More

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[Developing the Mathematical Method in order to Search for Latent Periodicity in Protein Amino Acid Sequences with Deletions and Insertions].

Biofizika 2015 Nov-Dec;60(6):1057-68

A mathematical method was developed in order to search for latent periodicity in protein amino acid and other symbolical sequences using the dynamic programming and random matrixes. The method permits detection of the latent periodicity with insertions and deletions in the previously unknown positions. The developed method was applied to search for the periodicity in the amino acid sequences of some proteins and the periodicity in EUR/USD exchange rate since 2001. Read More

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April 2016
1 Read

[Investigation of the Dependence of Escherichia coli RNA Polymerase σ70-Subunit Structure on Ionic Strength by Molecular Dynamics Simulation Method].

Biofizika 2015 Nov-Dec;60(6):1045-9

The σ70-subunit of E. coli RNA polymerase (a small protein, being a part of RNA holoenzyme, and responsible for initiation of transcription of constitutive genes) is modeled at different ionic strengths. Two variants of the location of C-end domain 4 are obtained. Read More

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