3,693 research outputs found

    Relationship of Oxidant and Antioxidant Markers to Asthma Severity in Egyptian Asthmatic Children

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    BACKGROUND: Asthma is a chronic airway disease which is characterized by oxidant antioxidant imbalance with the generation of oxidative stress related mediators.AIM: The study aimed to evaluate the role of asymmetric dimethylarginine, and malondialdehyde as oxidant markers and serum paraoxonase activity as an antioxidant marker in asthma, and to determine their relationship to the asthma severity and lung function among asthmatic children in Egypt.PATIENTS AND METHODS: This case control study was conducted on sixty patients with asthma compared with sixty apparently healthy children of matched age and sex.RESULTS: Serum concentrations of oxidant markers as asymmetric dimethylarginine and malondialdehyde were significantly increased in asthmatic patients while anti-oxidant marker as paraoxonase activity was significantly decreased compared to healthy controls (P < 0.05). ANOVA test revealed highly significant elevation of the serum concentrations of oxidant markers while anti-oxidant marker was significantly decreased in severe asthmatic patients (P < 0.001) compared to the patients with moderate and mild asthma respectively. Serum malondialdehyde concentration was a strong predictor of asthma severity by multiple regression analysis (P < 0.05).CONCLUSION: The study revealed an imbalance between oxidative and antioxidant defence systems in asthmatic children. Serum concentration of malondialdehyde was the most predictive biomarker having a significant association with asthma severity

    Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

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    The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum
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