710 research outputs found

    Interação do fator reumatóide e Entamoeba histolytica

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    The amoebae's cytotoxicity test and the amoebae's lysis test were used to show possible interactions between rheumatoid factor (RF) and Entamoeba histolytica. Amoebae's cytotoxic activity (ACA) was inhibited by affinity chromatography purified antiamoebae rabbit IgG (RIgG). Enhanced inhibition could be demonstrated with RIgG plus RF. But the same marked inhibition of ACA could be seen when replacing RF by heat inactivated normal human serum as a control. About 50% amoebae's lysis occurred when amoebae were brought together with native normal human serum (NNHS) as a source of complement. Amoebae's lysis increased to 60% when incubated with NHS plus human antiamoebae antibodies. No further augmentation could be obtained by the addition of RF. Using RIgG instead of human antibodies the lysis rate did not increase. Incubation of amoebae, NNHS, RIgG and RF even reduced amoebae's lysis. RF neither has an effect on ACA nor on complement mediated AL in vitro.Testes para citotoxicidade e lise amebiana foram utilizados para demonstrar uma possível interação entre o fator reumatóide e a Entamoeba histolytica. A atividade citotóxica amebiana foi inibida pela IgG antiameba de coelho purificada através de cromatografia. Constatou-se inibição aumentada com IgG antiameba de coelho mais fator reumatóide. A mesma inibição acentuada da atividade citotóxica amebiana pôde ser constatada quando se substituiu o fator reumatóide por soro humano normal, inativado pelo calor, como controle. Cerca de 50% de lise amebiana ocorreu quando as amebas foram misturadas com soro normal humano como fonte de complemento. A lise amebiana aumentou para 60% quando incubadas com soro humano normal, acrescido de anticorpos humanos antiameba. Nenhum aumento adicional pode ser obtido pela adição de fator reumatóide. Usando IgG antiameba de coelho em vez de anticorpos humanos, a proporção de lise não aumentou. A incubação de amebas com soro humano normal, IgG antiameba de coelho e fator reumatóide reduziu acentuadamente a lise amebiana. O fator reumatóide não teve efeito na atividade citotóxica amebiana, nem na lise amebiana mediada pelo complemento in vitro

    DOCUMENTARY CONTEXTS FOR THE ‘PISTIROS INSCRIPTION’

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    This preliminary study of the so-called ‘Pistiros Inscription’ challenges the dominantinterpretation of the document that has crystallized in the years since its preliminary publication,namely, that the inscription somehow guarantees the rights of traders operating within Pistiros.A reexamination of the rhetorical structure of the inscription and a reconstruction of the inscription’srelationship with preexisting documents on this subject, which are not extant, raises thepossibility that the function of the inscription was somewhat different than the communis opinio:the ‘Pistiros Inscription’ appears to have supplemented earlier regulation concerning Pistiros andto have attempted to limit the authority of an offi cial, possibly a Thracian royal, who exerciseddramatic power within Pistiros

    Exploring the Origins of Deuterium Enrichments in Solar Nebular Organics

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    Deuterium-to-hydrogen (D/H) enrichments in molecular species provide clues about their original formation environment. The organic materials in primitive solar system bodies have generally higher D/H ratios and show greater D/H variation when compared to D/H in solar system water. We propose this difference arises at least in part due to 1) the availability of additional chemical fractionation pathways for organics beyond that for water, and 2) the higher volatility of key carbon reservoirs compared to oxygen. We test this hypothesis using detailed disk models, including a sophisticated, new disk ionization treatment with a low cosmic ray ionization rate, and find that disk chemistry leads to higher deuterium enrichment in organics compared to water, helped especially by fractionation via the precursors CH2_2D+^+/CH3+_3^+. We also find that the D/H ratio in individual species varies significantly depending on their particular formation pathways. For example, from ∼20−40\sim20-40 AU, CH4_4 can reach D/H∼2×10−3\rm{D/H\sim2\times10^{-3}}, while D/H in CH3_3OH remains locally unaltered. Finally, while the global organic D/H in our models can reproduce intermediately elevated D/H in the bulk hydrocarbon reservoir, our models are unable to reproduce the most deuterium-enriched organic materials in the solar system, and thus our model requires some inheritance from the cold interstellar medium from which the Sun formed.Comment: 11 pages, 7 figures, accepted for publication in Ap

    The ancient heritage of water ice in the solar system

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    Identifying the source of Earth's water is central to understanding the origins of life-fostering environments and to assessing the prevalence of such environments in space. Water throughout the solar system exhibits deuterium-to-hydrogen enrichments, a fossil relic of low-temperature, ion-derived chemistry within either (i) the parent molecular cloud or (ii) the solar nebula protoplanetary disk. Utilizing a comprehensive treatment of disk ionization, we find that ion-driven deuterium pathways are inefficient, curtailing the disk's deuterated water formation and its viability as the sole source for the solar system's water. This finding implies that if the solar system's formation was typical, abundant interstellar ices are available to all nascent planetary systems.Comment: 33 pages, 7 figures including main text and supplementary materials. Published in Scienc

    Apollo, Ennodia, and fourth-century Thessaly

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    This paper explores the politics of cult in early fourth-century Thessaly, a period of prolonged stasis throughout the region. Two case studies are offered: The first explores Jason of Pherai’s planned expedition to Delphi in 370 and its potential impact on Thessalian corporate identity; the second reconstructs the role of Ennodia in the Pheraian tyrants’ attempts to win regional hegemony.Cet article étudie la politique cultuelle du début du ive siècle en Thessalie, une période de stasis prolongée dans la région. Deux études de cas sont proposées. La première aborde l’expédition planifiée par Jason de Phères à Delphes en 370 et son impact potentiel sur l’identité thessalienne. La seconde étude reconstruit le rôle d’Ennodia au sein des tentatives des tyrans pour imposer leur hégémonie à la région

    Reentrant nu = 1 quantum Hall state in a two-dimensional hole system

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    We report the observation of a reentrant quantum Hall state at the Landau level filling factor nu = 1 in a two-dimensional hole system confined to a 35-nm-wide (001) GaAs quantum well. The reentrant behavior is characterized by a weakening and eventual collapse of the nu = 1 quantum Hall state in the presence of a parallel magnetic field component B||, followed by a strengthening and reemergence as B|| is further increased. The robustness of the nu = 1 quantum Hall state during the transition depends strongly on the charge distribution symmetry of the quantum well, while the magnitude of B|| needed to invoke the transition increases with the total density of the system

    Even-denominator Fractional Quantum Hall Effect at a Landau Level Crossing

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    The fractional quantum Hall effect (FQHE), observed in two-dimensional (2D) charged particles at high magnetic fields, is one of the most fascinating, macroscopic manifestations of a many-body state stabilized by the strong Coulomb interaction. It occurs when the filling factor (ν\nu) of the quantized Landau levels (LLs) is a fraction which, with very few exceptions, has an odd denominator. In 2D systems with additional degrees of freedom it is possible to cause a crossing of the LLs at the Fermi level. At and near these crossings, the FQHE states are often weakened or destroyed. Here we report the observation of an unusual crossing of the two \emph{lowest-energy} LLs in high-mobility GaAs 2D holehole systems which brings to life a new \emph{even-denominator} FQHE at ν=1/2\nu=1/2
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