132 research outputs found

    On the nature of the solar-wind-Mars interaction

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    Plasma measurements near Mars on the U.S.S.R. Mars-2, -3, and -5 spacecraft are considered. The data are compared with simultaneous magnetic measurements. Strong evidence is obtained in favor of a direct interaction and mass exchange between the solar wind plasma and the gaseous envelope of Mars

    Simulation of the Neutral Particle Converter of the ARIES-L Device

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    AbstractThis paper presents the concept of Lunar regolith surface layer composition analysis using solar wind bombardment and registration of the sputtered and knocked out atoms converted into ions with solid-state converters and subsequent registration of ions by high-aperture electrostatic analyzer. Monte Carlo binary collision approximation code is used to calculate angular and energy distributions of scattered and sputtered atoms. Literature data are used for evaluation of charged fractions of scattered and sputtered components and SIMION code is used for calculation of charged particles trajectories in electrostatic deflector. The total sensitivity of the proposed scheme is evaluated

    Auto anti oxLDL, IgM and IgG: comparison between sedentary and athletes

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    Introduction: The practice of regular physical activity contributes to reduce the prevalence of coronary hearth disease (CHD) and aerobic exercises are associated with beneficial changes in the profile of circulating lipids and lipoproteins. However in the past years the oxidative hypothesis assumed great importance in the pathogenesis of CHD. During exhaustive exercises there is a greater possibility of oxidation of LDL, forming oxidized LDL (oxLDL) that has a key role in atherogenesis. However the incidence of coronary events in athletes is lower than in sedentary persons. It is described in the literature that we can found in serum auto autoantibodies anti-oxLDL, of the isotypes IgG and IgM. The former involved with atherogenesis and the latter with an atheroprotective function. The aim of this study was to verify if there are differences in the prevalence of the different autoantibodies between athletes and sedentary persons. Methods: Twenty male recreational runners and twenty male sedentary individuals living in the city of São Paulo were recruited for the study. Both the study protocol and consent form had been approved by the UNIFESP-EPM Ethics Committee. None of the participants were using lipid-lowering medications, no smokers, addicted to alcohol consumption, obese or had systemic arterial hypertension, neither liver, renal, metabolic, inflammatory or neoplastic diseases. Blood sample were collected at rest. Blood draws for all the individuals were performed after 12 hours of fasting. IgM and IgG anti ox LDL specific reactivity in serum, were measured by ELISA using previously stored serum. Student’s t-test was used to analyze differences in age and body mass index (BMI). The Mann-Whitney test was used to determine if the differences between the results for sedentary individuals and those for runners at rest were significant. Results: We found that at rest the group of athletes studied showed a statistically higher concentration of IgM autoantibodies against ox-LDL than controls (figure 1 a). At the same time, IgG autoantibodies anti ox-LDL presented the same concentration in controls and athletes (Figure 1 b). Conclusion: This finding is of extreme importance when we consider the prevalence of CHD in those different populations and the opposite actions of these two isotypes of antibodies

    The Structure of Martian Magnetosphere at the Dayside Terminator Region as Observed on MAVEN Spacecraft

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    We analyzed 44 passes of the MAVEN spacecraft through the magnetosphere, arranged by the angle between electric field vector and the projection of spacecraft position radius vector in the YZ plane in MSE coordinate system (θ{\theta} E ). All passes were divided into 3 angular sectors near 0{\deg}, 90{\deg} and 180{\deg} θ{\theta} E angles in order to estimate the role of IMF direction in plasma and magnetic properties of dayside Martian magnetosphere. The time interval chosen was from January 17 through February 4, 2016 when MAVEN was crossing the dayside magnetosphere at SZA ~ 70{\deg}. Magnetosphere as the region with prevailing energetic planetary ions is always found between the magnetosheath and the ionosphere. 3 angular sectors of dayside interaction region in MSE coordinate system with different orientation of the solar wind electric field vector E = -1/c V x B showed that for each sector one can find specific profiles of the magnetosheath, the magnetic barrier and the magnetosphere. Plume ions originate in the northern MSE sector where motion electric field is directed from the planet. This electric field ejects magnetospheric ions leading to dilution of magnetospheric heavy ions population, and this effect is seen in some magnetospheric profiles. Magnetic barrier forms in front of the magnetosphere, and relative magnetic field magnitudes in these two domains vary. The average height of the boundary with ionosphere is ~530 km and the average height of the magnetopause is ~730 km. We discuss the implications of the observed magnetosphere structure to the planetary ions loss mechanism.Comment: 24 pages, 13 figure

    Screening the Pathogen Box for Identification of New Chemical Agents with Anti-Fasciola hepatica Activity

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    Fascioliasis is an infectious parasitic disease distributed globally and caused by the liver fluke Fasciola hepatica or F. gigantica. This neglected tropical disease affects both animals and humans, and it represents a latent public health problem due to the significant economic losses related to its effects on animal husbandry. For decades, triclabendazole has been the unique anti-Fasciola drug that can effectively treat this disease. However, triclabendazole resistance in fascioliasis has more recently been reported around the world, and thus, the discovery of novel drugs is an urgent need. The aim of this study was to investigate the fasciocidal properties of 400 compounds contained in the Pathogen Box. The first stage of the screening was carried out by measuring the fasciocidal activity on metacercariae at a concentration of 33 mu M each compound (the standard dose). Subsequently, the activities of the most active compounds (n = 33) at their 50% inhibitory concentration (IC50) values against metacercariae were assayed, and the results showed that 13 compounds had IC(50)s of 50%. Four hit compounds were selected on the basis of their predicted nontoxic properties, and the IC50 values obtained for adult worms were <10 mu M; thus, these compounds represented the best fasciocidal compounds tested here. A cytotoxicity assay on four types of cell lines demonstrated that three compounds were nontoxic at their most active concentration. In conclusion, three hit compounds identified in this proof-of-concept study are potential candidates in the discovery of new fasciocidal drugs. Further studies are warranted

    Fibromyalgia: description of the syndrome in athletes and its implications

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    Fibromyalgia syndrome is a very common feature in the daily practice of rheumatologists. Therapy is based on the use of analgesics, anti-depressants, and other drugs. Many physicians indicate exercise, stretching, and relaxing programs as adjuvant therapies. It was surprising to find fibromyalgia in well-trained athletes. The syndrome, however, appears in athletes that reported recurrent tendon-muscle lesions. In this study, the authors analyzed a group of gymnastics and track and field athletes involved in competitive training. They found a significant incidence of the syndrome (7 in 20 subjects) in this group. This is an important finding, since fibromyalgia causes muscular pain and stiffness, and can predispose the athletes to muscle lesions and damage. Another important point regarding the syndrome is that some of its symptoms are related to overtraining and to the chronic fatigue syndrome. Therefore, the authors suggest that there is an important connection between those aspects.A fibromialgia é uma patologia de alta prevalência na população geral, cujo tratamento é feito por meio de medicamentos como antiinflamatórios, antidepressivos e miorrelaxantes, que pode ser complementado por medidas físicas como relaxamento, alongamento e exercícios físicos. A observação de fibromialgia entre atletas constatada em exames de rotina, em especial naqueles que apresentavam lesões musculares de repetição, levou os autores a pesquisar, de maneira prospectiva, um grupo de atletas praticantes de ginástica olímpica e atletismo, nos quais puderam confirmar alta incidência desta síndrome. Como a fibromialgia predispõe ao aparecimento de lesões por contratura muscular, sugerem que ela possa atuar como um mecanismo de indução ao surgimento de lesões musculares de repetição. Ainda devido às semelhanças dos sintomas encontrados na síndrome do supertreinamento, síndrome da fadiga crônica e fibromialgia, propõem uma possível ligação entre estes quadros.UNIFESP-EPMPMSP COTPUNIFESP-EPM Departamento de FisiologiaUSP Departamento de HistologiaUNIFESP, EPM, Depto. de FisiologiaSciEL

    Ion distribution dynamics near the Earth's bow shock: first measurements with the 2D ion energy spectrometer CORALL on the INTERBALL/Tail-probe satellite

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    International audienceThe dynamics of the ion distribution function near the Earth's bow shock is studied on the basis of quasi-3D measurements of ion energy spectra in the range of 30?24200 eV/q with the Russian-Cuban CORALL instrument on the INTERBALL/Tail-probe satellite. The instrument was designed for observations of magnetospheric plasma and measures ions, in an angular range of 36°?144° from the Earth-Sun direction. Ion populations generated by the Earth bow shock are often observed upstream from the bow shock. In the solar-wind stream compressed and heated by the passing of very dense magnetic cloud (CME), two types of these ion populations were measured upstream and before the bow shock crossing on 25 August 1995 at 07:37 UT. Both populations were observed in the energy range above 2 keV. At ~06:20 UT, when the angle between the direction of the interplanetary magnetic field and normal to the bow shock VBn was ? 43° the instrument observed a narrow, fast (~800 km/s) field-aligned beam moving from the Earth. At ~07:30, when Bn ? 28°, the wide ion pitch-angle distribution was observed. A similar suprathermal ion population is observed in the magnetosheath simultaneously with the solar-wind ion population being heated and deflected from the Sun-Earth direction. The similarity of observations during the mentioned time-interval and under usual solar-wind conditions allows us to conclude that types of suprathermal ion populations upstream and downstream from the bow shock do not depend on the solar-wind disturbance generated by magnetic cloud
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