27 research outputs found

    The CPLEAR detector at CERN

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    The CPLEAR collaboration has constructed a detector at CERN for an extensive programme of CP-, T- and CPT-symmetry studies using K0{\rm K}^0 and Kˉ0\bar{\rm K}^0 produced by the annihilation of pˉ\bar{\rm p}'s in a hydrogen gas target. The K0{\rm K}^0 and Kˉ0\bar{\rm K}^0 are identified by their companion products of the annihilation K±π∓{\rm K}^{\pm} \pi^{\mp} which are tracked with multiwire proportional chambers, drift chambers and streamer tubes. Particle identification is carried out with a liquid Cherenkov detector for fast separation of pions and kaons and with scintillators which allow the measurement of time of flight and energy loss. Photons are measured with a lead/gas sampling electromagnetic calorimeter. The required antiproton annihilation modes are selected by fast online processors using the tracking chamber and particle identification information. All the detectors are mounted in a 0.44 T uniform field of an axial solenoid of diameter 2 m and length 3.6 m to form a magnetic spectrometer capable of full on-line reconstruction and selection of events. The design, operating parameters and performance of the sub-detectors are described.

    Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases

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    The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular "reactive oxygen species" (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation. We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation). The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible. This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference

    Propofol administration to the fetal–maternal unit reduces cardiac oxidative stress in preterm lambs subjected to prenatal asphyxia and cardiac arrest

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    BACKGROUND: Little is known about the effects of propofol on oxidative stress and its effect on key structures of the contractile apparatus as the myosin light chain 2 (MLC2) and the p38MAPK survival pathway in the preterm heart. We hypothesized that propofol administration could attenuate the hypoxic myocardial injury after birth asphyxia. METHODS: Pregnant ewes were randomized to receive either propofol or isoflurane anesthesia. A total of 44 late-preterm lambs were subjected to in utero umbilical cord occlusion (UCO), resulting in asphyxia and cardiac arrest, or sham treatment. After emergency cesarean delivery, each fetus was resuscitated, mechanically ventilated, and supported under anesthesia for 8 h using the same anesthetic as the one received by its mother. RESULTS: At 8h after UCO, occurrence of reactive oxygen species and activation of inducible nitric oxide synthase in the heart were lower in association with propofol anesthesia than with isoflurane. This was accompanied by less degradation of MLC2 but higher p38MAPK level and in echocardiography with a trend toward a higher median left ventricular fractional shortening. CONCLUSION: The use of propofol resulted in less oxidative stress and was associated with less cytoskeletal damage of the contractile apparatus than the use of isoflurane anesthesia

    Hebraism and Humanism

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    The article presents the relationship between Christian Hebraism and Humanism between the end of the 15th and the first half of the 16th century. The polemical origins of Humanism as an anti-scholastic movement, and of Hebraism from Christian-Jewish controversies in the Middle-Ages are studied from the vantage point of selected, significant cases. The initial success and the final demise of the Christian Hebraist project are explained in term of the "limits of Humanism", that is to say the challenge the discovery of extra-Christian or extra-Catholic sources posed for the formation of early modern Western identity. The reaction against the integration of Hebrew among the Humanistic canon of the educational languages represents a convenient vantage point to observe the ultimate failure of the Humanistic project, or, in a more optimistic bend, its permanent perfectibility
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