90 research outputs found
Un cas de délire scientifico-patriotique : le docteur Edgar Bérillon
International audienceAu cours de la Première Guerre mondiale, le docteur Edgar Bérillon (1859-1948) développa une thèse selon laquelle les caractéristiques physiques et physiologiques des Allemands et des Français présentaient de grandes différences. Ses théories furent prises au sérieux par la communauté scientifique et médicale de l'époque, d'autant qu'elles participaient à la propagande générale contre l'ennemi. Ce délire scientifico-patriotique donna lieu à plusieurs publications, dont le contenu paraît aujourd'hui aussi faux que grotesque
The GB Virus C (GBV-C) NS3 Serine Protease Inhibits HIV-1 Replication in a CD4+ T Lymphocyte Cell Line without Decreasing HIV Receptor Expression
Introduction: Persistent infection with GBV-C (GB Virus C), a non-pathogenic virus related to hepatitis C virus (HCV), prolongs survival in HIV infection. Two GBV-C proteins, NS5A and E2, have been shown previously to inhibit HIV replication in vitro. We investigated whether the GBV-C NS3 serine protease affects HIV replication. Results: GBV-C NS3 protease expressed in a human CD4+ T lymphocyte cell line significantly inhibited HIV replication. Addition of NS4A or NS4A/4B coding sequence to GBV-C NS3 increased the effect on HIV replication. Inhibition of HI
Observation of Superfluidity of Polaritons in Semiconductor Microcavities
One of the most striking manifestations of quantum coherence in interacting
boson systems is superfluidity. Exciton-polaritons in semiconductor
microcavities are two-dimensional composite bosons predicted to behave as
particular quantum fluids. We report the observation of superfluid motion of
polaritons created by a laser in a semiconductor microcavity. Superfluidity is
investigated in terms of the Landau criterion and manifests itself as the
suppression of scattering from defects when the flow velocity is slower than
the speed of sound in the fluid. On the other hand, a Cerenkov-like wake
pattern is clearly observed when the flow velocity exceeds the speed of sound.
The experimental findings are in excellent quantitative agreement with the
predictions based on a generalized Gross-Pitaevskii theory, showing that
polaritons in microcavities constitute a very rich system for exploring the
physics of non-equilibrium quantum fluids.Comment: 14 pages, 3 figure
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