3,671 research outputs found

    Differential sensitivity of brainstem vs cortical astrocytes to changes in pH reveals functional regional specialization of astroglia

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    Astrocytes might function as brain interoceptors capable of detecting different (chemo)sensory modalities and transmitting sensory information to the relevant neural networks controlling vital functions. For example, astrocytes which reside near the ventral surface of the brainstem (central respiratory chemosensitive area) respond to physiological decreases in pH with vigorous elevations in intracellular Ca(2+) and release of ATP. ATP transmits astroglial excitation to the brainstem respiratory network and contributes to adaptive changes in lung ventilation. Here we show that in terms of pH-sensitivity ventral brainstem astrocytes are clearly distinct from astrocytes residing in the cerebral cortex. We monitored vesicular fusion in cultured rat brainstem astrocytes using total internal reflection fluorescence microscopy and found that approximately 35% of them respond to acidification with an increased rate of exocytosis of ATP-containing vesicular compartments. These fusion events require intracellular Ca(2+) signaling and are independent of autocrine ATP actions. In contrast, the rate of vesicular fusion in cultured cortical astrocytes is not affected by changes in pH. Compared to cortical astrocytes, ventral brainstem astrocytes display higher levels of expression of genes encoding proteins associated with ATP vesicular transport and fusion, including vesicle-associated membrane protein-3 and vesicular nucleotide transporter. These results suggest that astrocytes residing in different parts of the rat brain are functionally specialized. In contrast to cortical astrocytes, astrocytes of the brainstem chemosensitive area(s) possess signaling properties which are functionally relevant – they are able to sense changes in pH and respond to acidification with enhanced vesicular release of ATP

    Periodicity of professional pedagogical education within bachelor’s and master’s programmes in natural sciences

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    The article provides grounding and a methodological macro-development basis for a system periodic model of professional pedagogical education within bachelor's and master’s programmes in natural sciences. In the abovementioned context, periodicity is regarded as a universally applicable procedural basis for multilevel continuous professional pedagogical education in the sphere of natural sciences. A key category of system periodic model of professional pedagogical education within bachelor's and master’s programmes in natural sciences is a didactic cycle characterised by purposefulness, internal system integrity, dynamism, iterativity, controllability and hierarchy of levels based on phase logic. Didactic cycle is represented as a dual procedure of development of subject-subject relations oriented to correlation changes of self-balancing systems depending on quantitative augmentation in a form of grasping of content of professional pedagogical education within bachelor's and master’s programmes in natural sciences to qualitative personal transformations. Realisation of the hierarchy position is realised as macro-didactic, mesodidactic and micro-didactic cycles within the structure of a system model. Their attributive signs are goals, peculiarities of learning activity within the process of subject-subject dialogic interaction, types of solved tasks and performance. We have defined and characterised specificity of phases of didactic cycle: initiatives and perspectives, designing, implementation, assessment of results.peer-reviewe

    Tunable disorder in a crystal of cold polar molecules

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    In the present work, we demonstrate the possibility of controlling by an external field the dynamics of collective excitations (excitons) of molecules on an optical lattice. We show that a suitably chosen two-species mixture of ultracold polar molecules loaded on an optical lattice forms a phononless crystal, where exciton-impurity interactions can be controlled by applying an external electric field. This can be used for the controlled creation of many-body entangled states of ultracold molecules and the time-domain quantum simulation of disorder-induced localization and delocalization of quantum particles

    Contemporary challenges of state’s financial policy in the social sphere

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    The article is aimed at determining the bottlenecks of contemporary state’s financial policy development in social sphere and their relevant solutions. The study’s goal is considering the financial support of social sphere in conditions of curbing the state funding and widening the private financial sources without lowering the standard of living. It justifies the factors of social costs’ growth by spotting the social expenditures’ reserves, by analyzing the background of non-government funding sources of social services and by defining directions for further social solutions.peer-reviewe

    Modeling of Reactor of Straight–run Gasoline Fractions Refining on Zeolite Catalysts

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    Zeolites are widely used as catalysts and catalyst supports for fuel and lubricants production processes with enhanced performance properties. Design of industrial reactor requires the construction of a mathematical model and selection of optimal operating conditions for reducing the number of scaling stages. The authors have proposed a scheme of hydrocarbons conversion on zeolite catalysts, thermodynamics of reactions has been considered and the inverse kinetic problem has been solved. The model of reactor of straight–run gasoline fractions refining in software HYSYS Aspen Plus™ process simulator has been developed and its adequacy to experimental data has been shown

    THE INCREASING THE DURATION OF FUNCTIONAL BEVERAGES METHODS

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    In the Russia beverage market, functional beverages are increasingly popular with the population due to their intensive lifestyle and worsening environmental situation. Of great importance is the shelf life of drinks, since they determine the presence in the composition of useful nutrients that affect the various systems of functioning of the human body. The main groups of functional compounds are given. Ways to increase the shelf life of beverages, all aspects and their impact on the safety of the functional components of beverages are considered. The role of flavonoids as one of the groups of functional compounds has been evaluated. Recent studies on the effect of certain functional compounds on each other are given.In the Russia beverage market, functional beverages are increasingly popular with the population due to their intensive lifestyle and worsening environmental situation. Of great importance is the shelf life of drinks, since they determine the presence in the composition of useful nutrients that affect the various systems of functioning of the human body. The main groups of functional compounds are given. Ways to increase the shelf life of beverages, all aspects and their impact on the safety of the functional components of beverages are considered. The role of flavonoids as one of the groups of functional compounds has been evaluated. Recent studies on the effect of certain functional compounds on each other are given

    A comparative study of hydrophilic phosphine hexanuclear rhenium cluster complexes’ toxicity

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    Octahedral rhenium cluster compound Na2H8[{Re6Se8}(P(C2H4CONH2)(C2H4COO)2)6] has recently emerged as a very promising X-ray contrast agent for biomedical applications. However, the synthesis of this compound is rather challenging due to difficulty to control the hydrolysis of initial P(C2H4CN)3 ligand during the reaction process. Therefore, in this report we compare the in vitro and in vivo toxicity of Na2H8[{Re6Se8}(P(C2H4CONH2)(C2H4COO)2)6] with those of related compounds featuring fully hydrolysed form of the phosphine ligand, namely Na2H14[{Re6Q8}(P(C2H4COO)3)6] (Q = S or Se). Our results demonstrate that cytotoxicity and acute in vivo toxicity of the complex Na2H8[{Re6Se8}(P(C2H4CONH2)(C2H4COO)2)6] solutions were considerably lower than those of compounds with fully hydrolysed ligand P(C2H4COOH)3. Such behavior can be explained by the higher osmolality of Na2H14[{Re6Q8}(P(C2H4COO)3)6] versus Na2H8[{Re6Se8}(P(C2H4CONH2)(C2H4COO)2)6]
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