560 research outputs found

    Linear, diatomic crystal: single-electron states and large-radius excitons

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    The large-radius exciton spectrum in a linear crystal with two atoms in the unit cell was obtained using the single-electron eigenfunctions and the band structure, which were found by the zero-range potential (ZRP) method. The ground-state exciton binding energies for the crystal in vacuum appeared to be larger than the corresponding energy gaps for any set of the crystal parameters.Comment: 9 pages, 1 figure, 1 tabl

    The balance of pressor and depressor substances in the neurons of arcuate nucleus of hypothalamus in etiologically different arterial hypertension

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    Tishchenko S. V. The balance of pressor and depressor substances in the neurons of arcuate nucleus of hypothalamus in etiologically different arterial hypertension. Journal of Education, Health and Sport. 2019;9(4):492-502. eISNN 2391-8306. DOI http://dx.doi.org/10.5281/zenodo.2620542 http://ojs.ukw.edu.pl/index.php/johs/article/view/6858 The journal has had 7 points in Ministry of Science and Higher Education parametric evaluation. Part B item 1223 (26/01/2017). 1223 Journal of Education, Health and Sport eISSN 2391-8306 7 © The Authors 2019; This article is published with open access at Licensee Open Journal Systems of Kazimierz Wielki University in Bydgoszcz, Poland Open Access. This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author (s) and source are credited. This is an open access article licensed under the terms of the Creative Commons Attribution Non commercial license Share alike. (http://creativecommons.org/licenses/by-nc-sa/4.0/) which permits unrestricted, non commercial use, distribution and reproduction in any medium, provided the work is properly cited. The authors declare that there is no conflict of interests regarding the publication of this paper. Received: 05.04.2019. Revised: 15.04.2019. Accepted: 24.04.2019. The balance of pressor and depressor substances in the neurons of arcuate nucleus of hypothalamus in etiologically different arterial hypertension S. V. Tishchenko Zaporizhzhia State Medical University Department of Pathological Physiology Abstract It has been proved that arterial hypertension is not associated exclusively with an increase in vascular tone but also with a complex of pathological processes that results in cardiovascular pathology and lesions of the target organs. The central and peripheral contours of blood pressure regulation are well studied. Nevertheless, despite the presence of two regulatory contours the key structure that integrates and controls their function is the hypothalamus, in particular its arcuate nucleus. It is proved that the effectiveness of blood pressure regulation depends on those neuromodulators and neurohormones that are synthesized in the hypothalamus or transported to it. The most important neurohormones in the regulation of arterial blood presssure are brain natriuretic peptide, β-endorphin, neurotensin and angiotensin II. Equally important factor is the functional state of arcuate nucleus neurons, which depends on adequate blood supply, innervation and inter-neuronal relationships. The link between the above described processes is nitrogen monoxide system (NOS) and its universal messenger – nitric oxide NO. The purpose of the work was to determine the nature of the balance of pressor (angiotensin II and neurotensin) and depressor (brain natriuretic peptide and β-endorphin) neurohormones in the neurons of the arcuate nucleus of the hypothalamus and the ratio of NOS isoforms with hypertension of different etiology. Materials and methods. The studies were conducted on 32 mature male Wistar rats and 16 male spontaneously hypertensive rats. To study the content of neuropeptides and NOS enzyme isoforms, an immunohistochemical method was used, followed by digital image processing by Image J. The results that were obtained were calculated using the "Statistica 11.0" program. Conclusions 1. The same changes of neuropeptides’ content in hypothalamic arcuate nucleus are observed in the rats with arterial hypertension which are characterized by a decrease in the brain natriuretic peptide, β-endorphin and angiotensin II content with a significant increase in neurotensin content regardless of arterial hypertension etiology and pathogenesis. The peculiarities of the balance between depressor and pressor substances depend on the etiopathogenetic mechanisms – with the endocrine-salt model of arterial hypertension there is a significant predominance of depressor neuropeptides (in 4.3 times) whereas in essential hypertension this balance is similar to the control. 2. The changes of the NOS isoform ratio in the arcuate nucleus of hypothalamus are unidirectional, both with endocrine-salt model of arterial hypertension and essential hypertension – the content of eNOS decreases while nNOS and iNOS content increases. Key words: hypothalamus, arcuate nucleus, neuropeptides, nitric oxide, rats, arterial hypertensio

    The balance of pressor and depressor substances in the neurons of arcuate nucleus of hypothalamus in etiologically different arterial hypertension

    Get PDF
    It has been proved that arterial hypertension is not associated exclusively with an increase in vascular tone but also with a complex of pathological processes that results in cardiovascular pathology and lesions of the target organs. The central and peripheral contours of blood pressure regulation are well studied. Nevertheless, despite the presence of two regulatory contours the key structure that integrates and controls their function is the hypothalamus, in particular its arcuate nucleus. It is proved that the effectiveness of blood pressure regulation depends on those neuromodulators and neurohormones that are synthesized in the hypothalamus or transported to it. The most important neurohormones in the regulation of arterial blood presssure are brain natriuretic peptide, β-endorphin, neurotensin and angiotensin II. Equally important factor is the functional state of arcuate nucleus neurons, which depends on adequate blood supply, innervation and inter-neuronal relationships. The link between the above described processes is nitrogen monoxide system (NOS) and its universal messenger – nitric oxide NO. The purpose of the work was to determine the nature of the balance of pressor (angiotensin II and neurotensin) and depressor (brain natriuretic peptide and β-endorphin) neurohormones in the neurons of the arcuate nucleus of the hypothalamus and the ratio of NOS isoforms with hypertension of different etiology. Materials and methods. The studies were conducted on 32 mature male Wistar rats and 16 male spontaneously hypertensive rats. To study the content of neuropeptides and NOS enzyme isoforms, an immunohistochemical method was used, followed by digital image processing by Image J. The results that were obtained were calculated using the "Statistica 11.0" program. Conclusions 1. The same changes of neuropeptides’ content in hypothalamic arcuate nucleus are observed in the rats with arterial hypertension which are characterized by a decrease in the brain natriuretic peptide, β-endorphin and angiotensin II content with a significant increase in neurotensin content regardless of arterial hypertension etiology and pathogenesis. The peculiarities of the balance between depressor and pressor substances depend on the etiopathogenetic mechanisms – with the endocrine-salt model of arterial hypertension there is a significant predominance of depressor neuropeptides (in 4.3 times) whereas in essential hypertension this balance is similar to the control. 2. The changes of the NOS isoform ratio in the arcuate nucleus of hypothalamus are unidirectional, both with endocrine-salt model of arterial hypertension and essential hypertension – the content of eNOS decreases while nNOS and iNOS content increases

    Data acquisition system for the MuLan muon lifetime experiment

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    We describe the data acquisition system for the MuLan muon lifetime experiment at Paul Scherrer Institute. The system was designed to record muon decays at rates up to 1 MHz and acquire data at rates up to 60 MB/sec. The system employed a parallel network of dual-processor machines and repeating acquisition cycles of deadtime-free time segments in order to reach the design goals. The system incorporated a versatile scheme for control and diagnostics and a custom web interface for monitoring experimental conditions.Comment: 19 pages, 8 figures, submitted to Nuclear Instruments and Methods

    One-electron states and interband optical absorption in single-wall carbon nanotubes

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    Explicit expressions for the wave functions and dispersion equation for the band p - electrons in single-wall carbon nanotubes are obtained within the method of zero-range potentials. They are then used to investigate the absorption spectrum of polarized light caused by direct interband transitions in isolated nanotubes. It is shown that, at least, under the above approximations, the circular dichroism is absent in chiral nanotubes for the light wave propagating along the tube axis. The results obtained are compared with those calculated in a similar way for a graphite plane.Comment: 16 pages, 8 figures, 1 tabl

    Spatially and polarization resolved plasmon mediated transmission through continuous metal films

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    The experimental demonstration and characterization is made of the plasmon-mediated resonant transmission through an embedded undulated continuous thin metal film under normal incidence. 1D undulations are shown to enable a spatially resolved polarisation filtering whereas 2D undulations lead to spatially resolved, polarization independent transmission. Whereas the needed submicron microstructure lends itself in principle to CD-like low-cost mass replication by means of injection moulding and embossing, the present paper demonstrates the expected transmission effects on experimental models based on metal-coated photoresist gratings. The spectral and angular dependence in the neighbourhood of resonance are investigated and the question of the excess losses exhibited by surface plasmons is discusse
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