The in vitro Effect of a Magnetic Field on the Oxygen-Transport Function and the Gaseous Transmitter System in Blood

magnetic field, blood, oxygen, gaseous transmittersThe effect of an alternating magnetic field with a magnetic flux density of 150 mT on the blood oxygen-transport function was studied. In vitro exposure of blood cells was performed following a 10-day series of in vivo exposure of the rat tail artery in combination with administration of chemical compounds that affect the formation of gaseous transmitters. In vitro exposure to a magnetic field changed the oxygen-trans¬port function of the blood, as observed by a greater decrease in the affinity of hemoglobin for oxygen and an increase in the concentration of gaseous transmitters (nitric oxide and hydrogen sulfide). In animals to which nitroglycerin and sodium hydrosulfide were administered exposure to a magnetic field caused a shift in the oxyhemoglobin dissociation curve to the right; this effect was absent when a nonselective inhibitor of the NO synthase enzyme or an irreversible inhibitor of the cystathionine y-lyase enzyme was added. These results suggest that the magnetic field affects the oxygen-binding properties of the blood by modifying intra-erythrocyte mechanisms that involve gaseous transmitters

Green Tourism in the Context of Sustainable Development and the Challenges Posed by the Global Economic Crisis

The articles aims to substantiate the socio-economic, environmental, historical and cultural role played by green tourism and its contribution to the implementation of Sustainable Development Goals based on current innovative trends and capabilities of tourism in the face of challenges posed by the ongoing crisis in global economy caused by the latest pandemic. The objectives of the research were to detail the theoretical, methodological and applied approaches to the development of green tourism, which is a market sector providing travel services. The definition of green tourism has been made more profound through connecting it with the Sustainable Development Goals, which is rather logical. The motivating factors for the development of green tourism have been analyzed taking into account the model of multifunctionality in agriculture and its importance in rural development policy. The nature of changes in the green tourism sector has been identified with respect to the peculiarities of the current global situation, when a pandemic is restraining the world tourism intensity, on the one hand, and is stimulating local tourism, on the other. It is worth adding that local tourism is mostly green and focused on the conservation of the environmental and natural resources, as well as sustainment of mostly rural areas. The research carried out shows that green tourism can become a driving force for economic growth in rural areas, a motivator for employment, a factor in preserving rural culture and traditions in a particular area. At the same time, the results of the research prove the existence of a link between green tourism and national economic, environmental, socio-cultural, intellectual, energy security due to the most typical development priorities of such tourism. On analyzing the experience of the countries that suffered the pandemic most, we have found some prospects for green tourism development. It is a new system of partnership between the state, business and civil society which can become an additional incentive to preserve the potential of green tourism. Thus, strategic guidelines for green tourism development based on institutional priorities, with the current economic crisis challenges in mind, have been designed

Forced vibrations of piezoceramic cylindrical shells

Статтю присвячено аналізу проблеми вимушених коливань п’єзокерамічних циліндричних оболонок у вигляді коротких і високих кілець з радіальною поляризацією. Паралельно наведено просту ітераційну експериментально-обчислювальну методику визначення компонентів втрат енергії та коефіцієнтів зв’язку, яку ілюстровано розрахунками адмітансу коротких і високих кілець. Показано, що адмітанс, імпеданс і фазові кути не залежать від умов електричного навантаження, проте миттєва потужність дуже чутлива до режиму. Цей факт пояснює, чому режим заданої сталої напруги супроводжується значною нелінійністю, а в режимі заданого сталого струму такої нелінійності немає. Також досліджено напружений стан кілець. Встановлено, що чим більше відношення висоти до середнього діаметра кільця, тим вищий рівень крайової моди і тим сильніше розподіл головних напружень відрізняється від косинусоїди. В дуже коротких кільцях крайова мода не реєструється.This paper is devoted to the analysis of the forced vibrations problem for piezoceramic cylindrical shells in the form of short and high rings with radial polarization. Simultaneously a new simple technique for an experimental-computational determination of energy losses components as well as coupling factors is presented. An iterative determination process is illustrated by admittance calculations in resonance–anti-resonance frequency bands for strong modes. It is shown that the admittance, impedance, phase shifts are independent on exciting electric conditions. Sample power, sample voltage and sample current are very sensitive to loading circumstances. When vibrations of the piezoelectric sample are excited by the constant voltage, the instantaneous power in sample increases at resonance frequency in many times in respect to far-resonant frequencies case. And when vibrations of the piezoelectric sample are excited by the constant current, the instantaneous power in sample decreases at resonance frequency in that ratio. The instantaneous power reaches maximum value at resonances for the constant sample voltage and at anti-resonances for the constant sample current. This fact explains why the constant voltage regime is surrounded by significant nonlinearity but in the constant currant regime such phenomenon is absent. The stress state of rings was investigated too. Verification of vibration modes was made using the method of piezotransformer transducer. This method enables to determine the distribution of internal stresses for piezoceramic elements from measurements of the surface distribution of charges. For this purpose a number of small electrode-transducers have been divided in an exterior electrode coating of the cylindrical surface. Its potentials and charges are proportional to the sum of principal stresses. It was established that the greater the ratio of height to the middle diameter of the ring, the higher the level of edge mode and the more the distribution of main stresses is different from the cosine function. In a very short rings edge mode is not registered

Влияние электрического нагружения на вынужденные колебания поперечно поляризованных пьезокерамичнских стержней

Стаття присвячена аналізу експериментальних і розрахункових результатів, отриманих при дослідженні поздовжніх коливань тонких п’єзокерамічних стержнів з поперечною поляризацією в залежності від умов електричного навантаження - заданих сталих амплітуд струму або напруги. Показано, що повна провідність п’єзоелектричних зразків є добутком реактивної провідності їх міжелектродної ємності на відношення антирезонансного та резонансного визначників. Розрахунки провідності, коефіцієнтів зв’язку і тангенсів механічних та п’єзоелектричних втрат проведені на основі нової простої ітераційної методики. Дістала подальший розвиток ідея почергового вимірювання спадів напруг у модернізованій схемі Мезона, на основі чого визначаються фазові зсуви між компонентами повної провідності. Експериментальні дані добре узгоджуються з розрахованими величинами.This article analyzes the experimental and computational results obtained in the study of the longitudinal vibrations of thin piezoceramic bars with transverse polarization depending on the electrical load such as the given constant amplitude current or voltage. Calculations of the admittance, coupling coefficients, mechanical and piezoelectric loss tangents were made on the basis of a new simple iterative method. The idea of alternate measuring the voltage drop in the modernized Mason scheme was further developed, and the phase shifts between the components of admittance were determined. The experimental data are in good agreement with the calculated values.Статья посвящена анализу экспериментальных и расчетных результатов, полученных при исследовании продольных колебаний тонких пьезокерамических стержней с поперечной поляризацией в зависимости от условий электрического нагружения – заданных постоянных амплитуд тока или напряжения. Расчеты проводимости, коэффициентов связи и тангенсов механических и пьезоэлектрических потерь проведены на основе новой простой итерационной методики. Получила дальнейшее развитие идея поочередного измерения падений напряжения в модернизированной схеме Мэзона, на основе чего определяются фазовые сдвиги между компонентами полной проводимости. Экспериментальные данные хорошо согласуются с расчетными величинами

Thymic gland aspects in childhood: morpho-functional reciprocal relationships betwen thymus, nervous and endocrine system, in particular, with the somatotrophic axis hormones

Thymic gland (thymus) represents a huge mystery for biology, medicine (primarily immunology), including pediatric issues. Complexity of the study is determined by the multiplicity of integral connections of thymus with other components of immune system, neuroendocrine, hematopoietic systems, connective tissue, different organs and cells which provide appropriate barrier function. Discerning the direct thymic function from this continuum, or determining specific role of molecular factors (neuropeptides, growth hormone, etc.) upon the immune physiology represents a problem which is not yet resolved. In this review article dedicated to the current state of the problem, we consider the morphological and functional relationships between thymus, neuroendocrine system and, in particular, with hormones of the somatotropic axis. These interactions may also manifest by clinical heterogeneity which may be associated with impaired morphogenesis (organogenesis) at a very early stage of embryogenesis; namely, under the influence of gene family that determine the fate of each segment of the embryo-Hox genes which control the expression of other, functionally interconnected genes. Previously, T lymphocytes produced by the thymus and brain neurons have been shown to express the same antigen (Thy antigen), which was considered a specific antigen of T lymphocytes. A common molecular language, mediated by the molecules of intercellular interaction, was revealed which is used for the signal exchange between the cells, tissues and organs regulating the three mentioned systems (nervous, endocrine and immune). The interest of pediatricians in this field is associated with definite concept of human ontogenesis, from birth to elderly age, with thymic gland playing the main role, since antenatal period to early childhood. The main line of reasoning in this research area is not only theoretical, but also important from practical point of view. Since any critical involution of the thymus is accompanied by reduced number of produced and exported cells, a hormone-based therapy may be an alternative strategy to restore the organ by increasing thymocyte proliferation, and exporting mature T cells to peripheral lymphoid organs. Great opportunities have been opened in clinical immunology due to development of effective epistemological methods, e.g., genetic knock-out, transgenic animal models with human stem cell transfer, transplantation of hematopoietic and immunopoietic cells in primary and secondary immunodeficiencies, immune cell malignancies, autoinflammatory diseases, and, finally, infections of the immune system

Evolutionary aspects of thymology in pediatric practice

The thymus is now considered a derivative of the immune system being, to greater extent, its central organ. Immunodeficiency states and immune dysregulation also depend on the quality of the thymus, which may be determined both genetically and by fetopathic approach as well as due to the possibility and mode of its intravital injuries, age-related involution over different periods of life. Not accidentally, there are various morphometric bipolar states of the thymus gland in the pediatric population (3-7%), whereas its size may be sufficiently larger or smaller than the reference variable values. In certain cases, the phenomenon of thymomegaly (for example, in newborns) is considered a result of genetic errors (neuro-endocrine-immune syndrome with thymomegaly) induced by the mutated Hox genes. This syndrome may also be associated with congenital heart disorders. Moreover, the excessive morbidity in respiratory infections (commonly, viral by their etiology) among young children with bipolar thymus conditions remains the subject of sharp discussions. Some works assessing immune status in the children subjected to forced thymectomy, e.g., during heart surgery, yielded quite controversial results, even in cases of subtotal removal of thymus gland.Dialectically, the concepts of “morphology” and “organ function” could not be separated from one another. The morphometric transformations in organs (even transient ones) occuring within the range of > 95 and < 5 percentiles, should be almost always underlied by a certain pathomorphosis which require verification of their causes and origin. Even today, however, the assessment of thymus pathomorphology in the deceased children is not always critical, being often descriptive. This situation is, probably, associated with extreme complexity of thymic morphology assessment. The final point seems to be not set in the discussion about immunodeficiency states or immune dysregulation among children with bipolar thymus transformations. This is due to current absence of reliable immune-mediated biomarkers, the limited availability of genetic diagnostics in primary immunodeficiency conditions, and a decreased interest of clinical science in the issues of bipolar conditions of the thymus gland at the early age, in the absence of longitudinal observations in this category of patients, etc. In this article, the authors attempt to draw attention of researchers to this problem

Analysis of epidemiological situation of iodine deficiency in Tomsk region from 1998 to 2014

The purpose of the present research is the comparative analysis of the epidemiological situation of iodine deficiency in the Tomsk region from 1998 to 2014. There were examined 9901 and 15174 children of the school age including within the medical examination of the children's population in 1998 and 2014 in Tomsk. At all school pupils there were analyzed anamnestic data and carried out anthropometrical measurements, ultrasonography of the thyroid gland was carried out using the portable scanner "Aloka SSD 500" with the linear sensor of 7,5 MHz frequency in the real time, the thyroid volume was evaluated according to Delange (1997). The excretion of inorganic iodine was determined at 264 in 1998 and at 120 children in 2014, respectively, in a one-time portion of urine by the cerium-arsenic method. There was additionally carried out the analysis of results of determination of TSH at 10717 in 1998, and at 15091 in 2014 in a spot of the whole blood at newborn children on the 4-5 day after birth at full-term and on the 7-14 day at prematurely born children. Neonatal TSH in the dried-up samples of capillary blood was determined by the method of the fluorometric immune-ferment analysis with the use of sets of TSH-Neonatal: Delfia, Finland. Statistical processing of the data obtained was carried out with the use of the applied software package pspp. The descriptive analysis included calculation of the median for the quantitative and the calculation of frequencies for qualitative data. The comparative analysis included calculation of distinctions reliability by the Mann-Whitney criterion for independent and to Wilcoxon's criterion for dependent data. The comparative analysis of epidemiological situation of iodine deficiency in Tomsk and the Tomsk region in 1998 and 2014 specifies decreasing the iodine deficiency diseases in the Tomsk region, increasing the iodine provision of the population within 15 years by 27%, decreasing neonatal hyperthyroidism by 1.5 times

Изменения активности люциферазы в остром периоде клещевой микст-инфекции у детей

The research of clinical characteristics of different tick mixed infections etiological variants in children — tick-borne encephalitis, ixodid tick-borne borreliosis, granulocytic anaplasmosis and monocytic ehrlichiosis in human in Kemerovo region showed a possibility of feverish meningeal and meningoencephalitic forms of disease. The comparative analysis of mono- and mixed infections according to the principal clinical criteria showed the predominance of non-specific symptoms and more severe clinical course in mixed etiology, the pathognomonic for ixodid tick-borne borreliosis symptoms are rare. One of the main causes of severity of state and sequences of the disease is the autotoxemia syndrome. The use of the luciferase method in the diagnosing of the autotoxemia syndrome in tick mixed infections allows to predict the development of severe forms of the disease.Исследование клинических особенностей различных этиологических вариантов клещевых микст-инфекций у детей - клещевого энцефалита, иксодового клещевого боррелиоза, гранулоцитарного анаплазмоза и моноцитарного эрлихиоза человека - в Кемеровской области показало возможность развития заболевания в лихорадочной, менингеальной и менингоэнцефалитической формах. Сравнительный анализ моно- и микст-инфекций по основным клиническим критериям показал преобладание неспецифических симптомов и более тяжелое течение при смешанной этиологии болезни, редкое развитие патогномоничных для иксодового клещевого боррелиоза симптомов. Одной из ведущих причин, определяющих тяжесть состояния и последствия заболевания, является синдром эндогенной интоксикации. Использование люциферазного метода в диагностике синдрома эндогенной интоксикации при клещевых микст-инфекциях позволяет прогнозировать развитие тяжелых форм заболевания

Mitochondrial Structure, Function and Dynamics Are Temporally Controlled by c-Myc

Although the c-Myc (Myc) oncoprotein controls mitochondrial biogenesis and multiple enzymes involved in oxidative phosphorylation (OXPHOS), the coordination of these events and the mechanistic underpinnings of their regulation remain largely unexplored. We show here that re-expression of Myc in myc−/− fibroblasts is accompanied by a gradual accumulation of mitochondrial biomass and by increases in membrane polarization and mitochondrial fusion. A correction of OXPHOS deficiency is also seen, although structural abnormalities in electron transport chain complexes (ETC) are not entirely normalized. Conversely, the down-regulation of Myc leads to a gradual decrease in mitochondrial mass and a more rapid loss of fusion and membrane potential. Increases in the levels of proteins specifically involved in mitochondrial fission and fusion support the idea that Myc affects mitochondrial mass by influencing both of these processes, albeit favoring the latter. The ETC defects that persist following Myc restoration may represent metabolic adaptations, as mitochondrial function is re-directed away from producing ATP to providing a source of metabolic precursors demanded by the transformed cell