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The method of affordable colloidal synthesis of nanocrystalline Cu2ZnSnS4 (CZTS) is developed, which is suitable for obtaining bare CZTS nanocrystals (NCs), cation substituted CZTS NCs, and CZTS-based hetero-NCs. For the hetero-NCs, the synthesized in advance NCs of another material are introduced into the reaction solution so that the formation of CZTS takes place preferably on these "seed" NCs. Raman spectroscopy is used as the primary method of structural characterization of the NCs in this work because it is very sensitive to the CZTS structure and allows to probe NCs both in solutions and films. Raman data are corroborated by optical absorption measurements and transmission electron microscopy on selected samples. The CdTe and Ag NCs are found to be good seed NCs, resulting in a comparable or even better quality of the CZTS compound compared to bare CZTS NCs. For Au NCs, on the contrary, no hetero-NCs could be obtained under the given condition. Partial substitution of Zn for Ba during the synthesis of bare CZTS NCs results in a superior structural quality of NCs, while the introduction of Ag for partial substitution of Cu deteriorates the structural quality of the NCs.
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DNA double-strand breaks (DSBs) are associated with different physiological and pathological processes in different organisms. To understand the role of DSBs in multiple cellular mechanisms, a robust method for genome-wide mapping of chromosomal breaks at one-nucleotide resolution is required. Many years ago, we detected large DNA fragments migrating from DNA-agarose plugs in pulsed-field gels, which we named 'forum domains' [1,2]. Recently, we developed a method for genome-wide mapping of DSBs that produces these 50-150 kb DNA domains using microarrays or 454 sequencing (Tchurikov et al., 2011; 2013). Now we have used Illumina sequencing to map DSBs in repetitive rDNA units in human HEK293T cells. Here we describe in detail the experimental design and bioinformatics analysis of the data deposited in the Gene Expression Omnibus with accession number GSE49302 and associated with the study published in the Journal of Molecular Cell Biology (Tchurikov et al., 2014).
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The experimental results on syngeneic and allogeneic transplantation of whole fraction of mice bone marrow cells without irradiation have been presented. Data on the dynamics of the donor cell colonization of bone marrow, spleen, thymus and blood of the recipient mice were obtained. The degree of immunogenicity of donor cells with syngeneic and allogeneic bone marrow transplantation based on the microspectral fluorescence method was evaluated. Within the framework of the experiment a low degree of immunogenicity of donor cells with syngeneic and allogeneic transplantation is shown. Importantly, allogeneic bone marrow transplantation did not cause any reduction in the mean life span of mice. These data and the results of our previous studies, demonstrating the mean life span increased by 34% with syngeneic transplantation in line C57BL/6 EGFP+, allow for developing different methods of cell therapy with no risk of fatal consequences of the immunological incompatibility between donor and recipient.
Assuntos
Transplante de Medula Óssea , Sobrevivência de Enxerto , Proteínas de Fluorescência Verde/biossíntese , Quimeras de Transplante/metabolismo , Condicionamento Pré-Transplante/métodos , Aloenxertos , Animais , Feminino , Proteínas de Fluorescência Verde/genética , Isoenxertos , Masculino , Camundongos , Espectrometria de Fluorescência , Quimeras de Transplante/genéticaRESUMO
In this paper the experimental results of bone marrow transplantation from C57BL/6-Tg(ACTB-EGFP)1Osb/J transgenic mice into C57BL/6 mice subjected to 5-fluorouracil treatment are represented. It has been shown that EGFP+ cells engraftment in bone marrow, spleen and thymus of host mice after 5-Fu treatment significantly increased. More long-term engraftment was recorded after transplantation between closely related donors and 5-fluorouracil treatment hosts. We have also obtained data on differences in the dynamics of EGFP+ cells engraftment in host investigated organs. To assess the effect of the donor's bone marrow cells on the host immune system, functional activity of the synthetic apparatus (synthetic activity) of cells in bone marrow, spleen, thymus and blood have been investigated with fluorescence microspectral method. The results obtained allow of improving techniques for bone marrow transplantation without host irradiation in order to minimize the adverse effects.
Assuntos
Transplante de Medula Óssea , Fluoruracila/farmacologia , Sobrevivência de Enxerto , Proteínas de Fluorescência Verde/biossíntese , Imunossupressores/farmacologia , Quimeras de Transplante/metabolismo , Condicionamento Pré-Transplante , Animais , Proteínas de Fluorescência Verde/genética , Camundongos , Camundongos Transgênicos , Espectrometria de FluorescênciaRESUMO
In this paper the method of life span extension of multicellular organisms (human) using the reservation of stem cells followed by autotransplantation has been proposed. As the efficiency of this method results from the information theory of ageing, it is important to verify it experimentally testing the basic concepts of the theory. Taking it into consideration, the experiment on the bone marrow transplantation to old mice from young closely-related donors of the inbred line was carried out. It has been shown, that transplanted animals exhibited a survival advantage, a mean life span increased by 34% as compared to the control. This result not only demonstrates the efficiency of the proposed method for life span extension of multicellular organisms, but also confirms the basis of the information theory of ageing.
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Transplante de Medula Óssea , Longevidade , Modelos Biológicos , Aloenxertos , Animais , Camundongos , Camundongos TransgênicosRESUMO
In this article the method for studying 3-dimensional (stereological) characteristics of interactions of biological micro objects with nanoparticles on a basis of morphodensitometry analysis of standard 2-dimensional images of cytological and histological specimens is proposed. The performance of the task of determining the distance from registered nanoparticle to the center of the nucleus of the cell is described in detail. It is shown that using specific nanoparticles the results obtained may find application in science and diagnostics. Furthermore, it is possible to employ these results in nanotoxicology, in particular for determination of quantity characteristics of translocation of nanoparticles of different types in biological structures.
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Heterocromatina/química , Interfase , Nanopartículas/química , Núcleo Celular/química , Modelos TeóricosRESUMO
The new method of total nonspecific vaccination of humans and animals is presented based on the experience of practical use of a powerful light pulse for air disinfection in laboratory facilities.
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Luz , Vacinação em Massa/instrumentação , Vacinação em Massa/métodos , Animais , HumanosRESUMO
The changes in the sea level relative to the position of the Serapeo Temple in Pozzuoly (Italia) over a period of 2100 years are discussed in the context of the well known periods of climate cooling off (Neoglacial, Little Ace Period) and climate warming (Middle Ages Optimum, Modern climate warming). It is noted that the rate of sea level lifting relative to the position of the Serapeo Temple in the modern phase of climate warming, which began the end of the 18th Century is approximately two times higher than in the previous phase of climate warming in the period from the fifth to the mid-tenth century A.D. This indicates that not only the natural cyclic component contributes to the mechanisms of Modern Climate warming but also the anthropogenic component of approximately equivalent power, which results from the waste of CO2 caused by the burning of fossilized fuels.
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Mudança Climática/história , Monitoramento Ambiental/história , Temperatura , Arquitetura , Planeta Terra , Aquecimento Global/história , História do Século XV , História do Século XVI , História do Século XVII , História do Século XVIII , História do Século XIX , História do Século XX , História do Século XXI , História Antiga , História Medieval , Itália , Oceanos e MaresRESUMO
An informational hypothesis of aging has been formulated, and an imitational model of the survival of a population of multicellular organisms under conditions of informational degradation of the cell genetic material (accumulation of random errors in the genome) has been constructed. It is assumed that the basic mechanism of "rejuvenation" (decrease in the number of errors) of the genetic material during its transition from parents to their progeny is the phenomenon of crossing-over during gametogenesis and the competitive selection of gametes participating in the formation of the progenitor genetic material. Within the framework of the imitational model, it is shown that this mechanism, which exists in most eukaryotes, provides the stability of the population gene pool in a large number of generations, whereas in a single organism, the amount of genome errors increases with aging.
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Envelhecimento/fisiologia , Células Eucarióticas/fisiologia , Genoma/fisiologia , Células Germinativas/fisiologia , Modelos Biológicos , AnimaisAssuntos
Desenvolvimento Embrionário , Animais , Blastocisto/citologia , Fase de Clivagem do Zigoto/citologia , Feminino , Técnicas In Vitro , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Microscopia de Vídeo , Mórula/citologia , Gravidez , Fatores de Tempo , Zigoto/crescimento & desenvolvimentoRESUMO
It has been shown that theoretical group methods can be applied in studies of complex physical and biological systems in which the phenomenon of self-organization takes place. The problem of calculating the parameters of climatic sensitivity with allowance for the cyclone-anticyclone structure of the atmosphere optically dense in the infrared region is considered as an example.
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Clima , Modelos BiológicosRESUMO
A theoretical model of the mechanism of action of weak electromagnetic fields on water solutions has been constructed. The model predicts the redistribution of protons on spatial inhomogeneities in water medium. It is shown that an external field leads to the phasing of ions on the standing wave, which is considered as an inhomogeneity. As a result of an inhomogeneous distribution of hydrogen ions, local regions with a higher and lower acidity arise. The acidity of medium substantially affects the rate of chemical reactions; therefore, the exposure to a weak external field can change this parameter. The effect of local changes in acidity on the rate of hydrogen peroxide production was considered. It was predicted that the exposure to a weak electromagnetic field with particular parameters can increase the rate and, as a consequence, the concentration of hydrogen peroxide in solution.
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Peróxido de Hidrogênio/química , Modelos Químicos , Água , Campos Eletromagnéticos , Concentração de Íons de Hidrogênio , Prótons , SoluçõesRESUMO
The definition of the cause-effect model of a phenomenon and the rules of presenting these models in the form of cause-effect diagrams have been formulated. The relationship between cause-effect modeling and traditional methods of mathematical modeling has been analyzed. Examples of cause-effect models (diagrams) of phenomena of different physical nature are given, and the application of these models in studies of some problems is demonstrated. In particular, the mechanism of renormalizing the rate constans of chemical reactions in terms of dissipative resonance is considered. In addition, the renormalization of the climate sensitivity parameters and the relaxation time of the Earth climate system in terms of the two-component (CO2 + H2O) greenhouse effect is considered.
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Ecossistema , Efeito Estufa , Modelos Teóricos , Ecologia/métodosRESUMO
The variants of the identification method were considered that take the a priori information about the evolution of a system under study and the type of experimental errors of the dynamic parameters of the system into account. An example of using this method for the identification of a biochemical reaction is given where the error in measuring the dynamic parameters (concentration of substances) has both an absolute and a relative components.
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Algoritmos , Modelos Teóricos , Análise de Sistemas , Inibidores do Fator Xa , Cinética , Lipoproteínas/fisiologia , Dinâmica não LinearRESUMO
A correlation between the functional (synthetic) activity of animal blood lymphocytes and the intensity of radiation of the Sun at a frequency of 2800 MHz in 2000 and 2002 was studied. The results were compared with the data obtained in 1993 and 1994. These data suggest that there are seasonal regularities in the interrelationship of the processes studied. A change in the sign of the correlation coefficients at the maximum of the 23rd solar cycle was shown. Possible mechanisms of the phenomena are discussed.
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Núcleo Celular/efeitos da radiação , Linfócitos/efeitos da radiação , Atividade Solar , Animais , Núcleo Celular/metabolismo , Linfócitos/metabolismo , Linfócitos/ultraestrutura , Masculino , Ratos , Ratos Wistar , Espectrometria de FluorescênciaRESUMO
A wide range of biophysical systems are described by nonlinear dynamic models mathematically presented as a set of ordinary differential equations in the Cauchy explicit form: [formula: see text] Fij(X1(t),..,XN(t),t), (i = 1,...,N, j = 1,...,M), where Fij (X1(t), ..., XN(t), t) is a set of basis functions satisfying the Lipschitz condition. We investigate the problem of evaluation of model constants aij (the system identification) using experimental data about the time dependence of the dynamic parameters of the system Xi(t). A new method of system identification for the class of similar nonlinear dynamic models is proposed. It is shown that the problem of identifying an initial nonlinear model can be reduced to the solution of a system of linear equations for the matrix of the dynamic model constants [aj]i. It is proposed to determine the set of dynamic model constants aij using the criterion of minimal quadratic discrepancy for the time dependence of the set of dynamic parameters Xi(t). An important special case of the nonlinear model, the quadratic model, is considered. Test problems of identification using this method are presented for two nonlinear systems: the Van der Pol type multiparametric nonlinear oscillator and the strange attractor of Ressler, a widely known example of dynamic systems showing the stochastic behavior.
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Biofísica , Interpretação Estatística de Dados , Algoritmos , Fenômenos BiofísicosRESUMO
An associated culture of nervous ganglia and gonads was used to study the gametogenesis neuroendocrine regulation in mollusks (Mytilus edulis L.). The state of oocytes was controlled by microspectral fluorescent analysis on slides stained with acridine orange. The object of investigations was Mytilus edulis L. collected in La Manch in April-May. A microspectrofluorimetrical investigation of samples was carried out in Pushchino. As a criterion of cell synthetic activity, the parameter alpha was used. Parameter alpha is the ratio of fluorescence intensities in the red (I640) and green (I530) regions of the visible spectrum: alpha = I640/I530. The results obtained showed that the nervous system realized the endocrine regulation of gametogenesis in mollusks. There was no normal development of oocytes in an isolated mantle culture. The development of oocytes in a tissue culture proceeds in a similar manner as in the gonads of the native organism in normal natural conditions only if the mantle tissue is associated either with all nervous ganglia or with the cerebral ganglion alone. It was found that the cerebral ganglion plays a key role in the neuroendocrine regulation of gametogenesis.
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Bivalves/fisiologia , Células Germinativas/crescimento & desenvolvimento , Sistemas Neurossecretores/fisiologia , Espectrometria de Fluorescência/métodos , AnimaisRESUMO
The system identification method for a variety of nonlinear dynamic models is elaborated. The problem of identification of an original nonlinear model presented as a system of ordinary differential equations in the Cauchy explicit form with a polynomial right part reduces to the solution of the system of linear equations for the constants of the dynamical model. In other words, to construct an integral model of the complex system (phenomenon), it is enough to collect some data array characterizing the time-course of dynamical parameters of the system. Collection of such a data array has always been a problem. However difficulties emerging are, as a rule, not principal and may be overcome almost without exception. The potentialities of the method under discussion are demonstrated by the example of the test problem of multiparametric nonlinear oscillator identification. The identification method proposed may be applied to the study of different biological systems and in particular the enzyme kinetics of complex biochemical reactions.