Dilute ferrimagnetic semiconductors in Fe-substituted spinel ZnGa2_2O4_4

Solid solutions of nominal composition [ZnGa$_2$O$_4$]$_{1-x}$[Fe$_3$O$_4$]$_x$, of the semiconducting spinel ZnGa$_2$O$_4$ with the ferrimagnetic spinel Fe$_3$O$_4$ have been prepared with $x$ = 0.05, 0.10, and 0.15. All samples show evidence for long-range magnetic ordering with ferromagnetic hysteresis at low temperatures. Magnetization as a function of field for the $x$ = 0.15 sample is S-shaped at temperatures as high as 200 K. M\"ossbauer spectroscopy on the $x$ = 0.15 sample confirms the presence of Fe$^{3+}$, and spontaneous magnetization at 4.2 K. The magnetic behavior is obtained without greatly affecting the semiconducting properties of the host; diffuse reflectance optical spectroscopy indicates that Fe substitution up to $x$ = 0.15 does not affect the position of the band edge absorption. These promising results motivate the possibility of dilute ferrimagnetic semiconductors which do not require carrier mediation of the magnetic moment.Comment: 9 pages and 6 figure

The features of the structural organization of spinal ganglia in a subphylum of vertebtates

Fig. 6. Fragment of microscopic structure of spinal ganglion of domestic bull: a — neurocytes; b — cores if glial cells; c — nerval fibers. Hematoxilin and eosin. ×120.Published as part of Goralskiy, L. P., Guralska, S. V., Kolesnik, N. L. & Sokulskiy, I. M., 2018, The Features Of The Structural Organization Of Spinal Ganglia In A Subphylum Of Vertebtates, pp. 501-508 in Vestnik Zoologii 52 (6) on page 506, DOI: 10.2478/vzoo-2018-0051, http://zenodo.org/record/645498

On the origin of the HI holes in the interstellar medium of dwarf irregular galaxies

We suggest that large HI holes observed in the interstellar medium (ISM) of galaxies such as the Large Magellanic Cloud (LMC) and Holmberg II (Ho II, DDO 50, UGC 4305) can form as the combined result of turbulence coupled to thermal and gravitational instabilities. We investigate this problem with three dimensional hydrodynamical simulations, taking into account cooling and heating processes and the action of the self-gravity of the gas. We construct an algorithm for radiative transfer to post-process the simulated data and build emission maps in the 21 cm neutral hydrogen line. With this approach, we are able to reproduce the structure of the shells and holes as observed in regions of the ISM, where no stellar activity is detected. In order to quantify the comparison of our synthetic maps to the observations, we calculate the physical scale-autocorrelation length relation (L-L_{cr} relation) both on the synthetic HI maps and the HI map of Ho II. The L-L_{cr} relation shows a linear increase of the autocorrelation length with the physical scale up to the scale of energy injection and flattens for larger scales. The comparison of the L-L_{cr} relation between the observations and the synthetic maps suggests that turbulence is driven in the ISM of Ho II on large scales (~ 6 kpc). The slope of the L-L_{cr} relation in the linear regime in Ho II is better reproduced by models where turbulence is coupled with a weak efficiency cooling of the gas. These results demonstrate the importance of the interplay between turbulence and the thermodynamics of the gas for structure formation in the ISM. Our analysis can be used to determine the scale on which kinetic energy is injected in the ISM of dwarf irregular galaxies, and to derive, in a first approximation, the cooling rate of the gas.Comment: 36 pages, 13 figures, 1 table. Revised version, accepted to Ap

Nanosized superparamagnetic precipitates in cobalt-doped ZnO

The existence of semiconductors exhibiting long-range ferromagnetic ordering at room temperature still is controversial. One particularly important issue is the presence of secondary magnetic phases such as clusters, segregations, etc... These are often tedious to detect, leading to contradictory interpretations. We show that in our cobalt doped ZnO films grown homoepitaxially on single crystalline ZnO substrates the magnetism unambiguously stems from metallic cobalt nano-inclusions. The magnetic behavior was investigated by SQUID magnetometry, x-ray magnetic circular dichroism, and AC susceptibility measurements. The results were correlated to a detailed microstructural analysis based on high resolution x-ray diffraction, transmission electron microscopy, and electron-spectroscopic imaging. No evidence for carrier mediated ferromagnetic exchange between diluted cobalt moments was found. In contrast, the combined data provide clear evidence that the observed room temperature ferromagnetic-like behavior originates from nanometer sized superparamagnetic metallic cobalt precipitates.Comment: 20 pages, 6 figures; details about background subtraction added to section III. (XMCD

The role of NO in signaling pathway in cardiac ischemic preconditioning against myocardial ischemia-reperfusion injury

Many recent studies have confirmed the effect of NO and that its relative signaling pathway is important for preconditioning of the cardioprotective effect. Mitochondria as a target for the cardioprotective effects of nitric oxide in ischemia-reperfusion injury is considered to be the ultimate goal of cardioprotection. During preconditioning, signaling is initiated from the sarcolemmal membrane and then spread into the cytoplasm via many series of enzymes, including nitric oxide synthase (NOS), soluble guanylyl cyclase (sGC), and protein kinase G (PKG). As a result, the signal is transmitted into the mitochondria, where the cardioprotective effect occurs. It is now well established that mitochondria act to protect the heart against ischemia-reperfusion injury via the opening of the mitochondrial ATP-sensitive K+ channel and the inhibition of mitochondrial permeability transition. This knowledge may be useful in developing novel strategies for clinical cardioprotection from ischemia-reperfusion injury

Magnetic phase diagram of cubic perovskites SrMn_1-xFe_xO_3

We combine the results of magnetic and transport measurements with Mossbauer spectroscopy and room-temperature diffraction data to construct the magnetic phase diagram of the new family of cubic perovskite manganites SrMn_1-xFe_xO_3. We have found antiferromagnetic ordering for lightly and heavily Fe-substituted material, while intermediate substitution leads to spin-glass behavior. Near the SrMn_0.5Fe_0.5O_3 composition these two types of ordering are found to coexist and affect one another. The spin glass behavior may be caused by competing ferro- and antiferromagnetic interactions among Mn^4+ and observed Fe^3+ and Fe^5+ ions.Comment: 8 pages, 10 figures, revtex, accepted to Phys. Rev.

Еволюційна морфологія спинномозкових вузлів пойкілотермних хребетних тварин

An important issue of modern neuromorphology of animals is the study of spinal cord nodes, which play an important role as primary centers on the way to transmit sensory information from receptors to the central nervous system, providing appropriate reactions to the action of certain factors. The scientific article uses material that is a fragment of the research work of the department of normal and pathological morphology, hygiene and expertise “Development, morphology and histochemistry of animal organs in normal and pathological conditions”, state registration number – 0120U100796. Using anatomical, morphological, neurohistological and statistical methods of research, the histomorphology of spinal cord nodes in a comparative anatomical series of vertebrates: bony fish, amphibians, reptiles, which differ in motor activity and their place of existence in a certain environment, was clarified in the work. It has been established that in the process of phylogenesis, a certain structural and morphofunctional reorganization of the spinal nodes occurs. They differ in shape and size. Adaptation to various living conditions of animals was formed on the basis of changes in the density and size of neurons, their morphological structures, an increase in the total number of gliocytes and glial cells, and polymorphism in the degree of chromatophilia. Thus, according to neurohistological studies, it has been noted that the neurons of the spinal cord nodes of cold-blooded animals (pond frog, pond lizard) are characterized by a functional degree of relative polymorphism – chromatophilia. With the total impregnation of the spinal cord nodes with silver nitrate according to the Bolshovsky-Gross method, different intensity of staining of nerve cells is found in all the studied animals: light, light-dark and dark. It was found that the neurocytes of all groups of vertebrates differ in the volume of the perikaryon, the nucleus and the nuclear-cytoplasmic ratio, which is related to the peculiarities of species and age-related neuromorphology, the morpho-functional state of the nervous system and the type of higher nervous activity. Nissl staining of histopreparations of spinal nodes of poikilothermic animals showed that the neuroplasm of nerve cells of spinal nodes contains deep basophilic substances in the form of small grains of varying density. In carp neurons, the basophilic substance is concentrated on the periphery of the dust-like neuroplasm. Nuclear chromatin is more pronounced in the pond frog than in the carp, the depths of which are much larger. It should be noted that the highest degree of development of the protein-synthesizing apparatus is characteristic of the neurocytes of the spinal nodes of the swift lizard, compared to the previously studied vertebrates. The obtained research results have not only important general biological significance, which complements and expands modern scientific ideas about certain regularities of morpho-functional rearrangements of spinal cord nodes in a comparative anatomical series, but also serve to develop new material and substantiate the morpho-functional assessment of species morphological differences of the nervous system of poikilothermic vertebrates, adapted to different conditions of existence in the environment.Важливим питанням сучасної нейроморфології тварин є дослідження спинномозкових вузлів, які виконують важливу роль первинних центрів на шляху передачі сенсорної інформації від рецепторів до центральної нервової системи, забезпечуючи відповідні реакції на дію певних чинників. У науковій статті використано матеріал, який є фрагментом науково-дослідної роботи кафедри нормальної і патологічної морфології, гігієни та експертизи “Розвиток, морфологія та гістохімія органів тварин у нормі та при патології”, номер державної реєстрації – 0120U100796. У роботі за допомогою анатомічних, морфологічних, нейрогістологічних та статистичних методів досліджень з’ясовано гістоморфологію спинномозкових вузлів пойкілотермних хребетних тварин у порівняльному аспекті: кісткових риб, амфібій, рептилій, які відрізняються руховою активністю, місцем існування їх у певному середовищі. Встановлено, що у процесі філогенезу відбувається певна структурна та морфофункціональна перебудова спинномозкових вузлів. Вони відрізняються за формою і розмірами. Адаптація до різноманітних умов існування тварин сформувалася на основі змін щільності та розмірів нейронів, їх морфологічних структур, збільшення загальної кількості гліоцитів і клітин глії, поліморфізму за ступенем хроматофілії. Так, за нейрогістологічними дослідженнями встановлено, що нейронам спинномозкових вузлів холоднокровних тварин (ставкова жаба, ящірка прудка) притаманний функціонуючий ступінь поліморфізму щодо хроматофілії. При тотальній імпрегнації спинномозкових вузлів азотнокислим сріблом за методом Більшовський-Грос у всіх досліджуваних тварин виявляється різна інтенсивність забарвлення нервових клітин: світлі, світло-темні і темні. З’ясовано, що нейроцити всіх груп хребетних тварин відрізняються об’ємом перикаріона, ядра і ядерно-цитоплазматичним відношенням, що пов’язано з особливостями видової та вікової нейроморфології, морфофункціональним станом нервової системи і типом вищої нервової діяльності. Фарбування гістопрепаратів за Нісслем спинномозкових вузлів пойкілотермних тварин показало, що нейроплазма нервових клітин спинномозкових вузлів містить глибки базофільної речовини у вигляді дрібних зерен різної щільності. У нейронах коропа базофільна речовина зосереджена на периферії нейроплазми пилеподібного вигляду. Ядерний хроматин більш виражений у ставкової жаби, ніж у коропа, глибки якого значно крупніші. Варто зазначити, що, найвищий ступінь розвитку білоксинтезуючого апарату характерний для нейроцитів спинномозкових вузлів прудкої ящірки, порівняно з попередніми досліджуваними хребетними тваринами. Отримані результати дослідження мають не тільки важливе загальнобіологічне значення, яке доповнює та розширює сучасні наукові уявлення про певні закономірності морфофункціональних перебудов спинномозкових вузлів у порівняльно-анатомічному ряді, а й слугують для розробки нового матеріалу і обґрунтування морфофункціональної оцінки видових морфологічних відмінностей нервової системи пойкілотермних хребетних тварин, адаптованих до різних умов існування у довкіллі

Magnetic oxide semiconductors

Magnetic oxide semiconductors, oxide semiconductors doped with transition metal elements, are one of the candidates for a high Curie temperature ferromagnetic semiconductor that is important to realize semiconductor spintronics at room temperature. We review in this paper recent progress of researches on various magnetic oxide semiconductors. The magnetization, magneto-optical effect, and magneto-transport such as anomalous Hall effect are examined from viewpoint of feasibility to evaluate the ferromagnetism. The ferromagnetism of Co-doped TiO2 and transition metal-doped ZnO is discussed.Comment: 26 pages, 5 tables, 6 figure

Dynamics of parameters of elastic-elastic properties of arterial wall in patients with morbid obesity after conduction of bariatric treatment.

According to the World Health Organization, 2.8 million people die every year from diseases associated with overweight or obesity. Abdominal-visceral form is a serious predictor of mortality from cardiovascular disease. The aim of the work was to evaluate the dynamics of rigidity of the arterial wall in patients with morbid obesity after the administration of bariatric treatment. The study included 22 patients with morbid obesity, 11 women and 11 men (50%). The average age of patients was 41.9 ± 2.38 years. All patients were under the supervision of a multidisciplinary team of State Establishment "Dnepropetrovsk Medical Academy of Health Ministry of Ukraine", which included surgeons, anesthetists, cardiologists and endocrinologists. Weight loss after bariatric treatment of obesity was accompanied by positive changes in the cardiometabolic profile in patients, which was manifested not only by improving blood pressure control, decreasing doses and the number of medications taken, but also reducing the rigidity of the arterial wall, which in turn led to the reduction of the risk of serious cardiovascular events in future

Suppressor of cytokine signaling (SOCS)5 ameliorates influenza infection via inhibition of EGFR signaling

© Kedzierski et al. Influenza virus infections have a significant impact on global human health. Individuals with suppressed immunity, or suffering from chronic inflammatory conditions such as COPD, are particularly susceptible to influenza. Here we show that suppressor of cytokine signaling (SOCS) five has a pivotal role in restricting influenza A virus in the airway epithelium, through the regulation of epidermal growth factor receptor (EGFR). Socs5-deficient mice exhibit heightened disease severity, with increased viral titres and weight loss. Socs5 levels were differentially regulated in response to distinct influenza viruses (H1N1, H3N2, H5N1 and H11N9) and were reduced in primary epithelial cells from COPD patients, again correlating with increased susceptibility to influenza. Importantly, restoration of SOCS5 levels restricted influenza virus infection, suggesting that manipulating SOCS5 expression and/or SOCS5 targets might be a novel therapeutic approach to influenza