Jagiellonian University

About: Jagiellonian University is a education organization based out in Krakow, Poland. It is known for research contribution in the topics: Population & Catalysis. The organization has 17438 authors who have published 44092 publications receiving 862633 citations. The organization is also known as: Academia Cracoviensis & Akademia Krakowska.

Performance of electron and photon triggers in ATLAS during LHC Run 2

Abstract: Electron and photon triggers covering transverse energies from 5 GeV to several TeV are essential for the ATLAS experiment to record signals for a wide variety of physics: from Standard Model processes to searches for new phenomena in both proton–proton and heavy-ion collisions. To cope with a fourfold increase of peak LHC luminosity from 2015 to 2018 (Run 2), to 2.1×1034cm-2s-1, and a similar increase in the number of interactions per beam-crossing to about 60, trigger algorithms and selections were optimised to control the rates while retaining a high efficiency for physics analyses. For proton–proton collisions, the single-electron trigger efficiency relative to a single-electron offline selection is at least 75% for an offline electron of 31 GeV, and rises to 96% at 60 GeV; the trigger efficiency of a 25 GeV leg of the primary diphoton trigger relative to a tight offline photon selection is more than 96% for an offline photon of 30 GeV. For heavy-ion collisions, the primary electron and photon trigger efficiencies relative to the corresponding standard offline selections are at least 84% and 95%, respectively, at 5 GeV above the corresponding trigger threshold.

Neuromelanin can protect against iron-mediated oxidative damage in system modeling iron overload of brain aging and Parkinson’s disease

Abstract: In Parkinson's disease (PD), dopamine neurons containing neuromelanin selectively degenerate Neuromelanin binds iron and accumulates in aging Iron accumulates in reactive form during aging, PD, and is involved in neurodegeneration It is not clear how the interaction of neuromelanin and iron can be protective or toxic by modulating redox processes Here, we investigated the interaction of neuromelanin from human substantia nigra with iron in the presence of ascorbic acid, dopamine, and hydrogen peroxide We observed that neuromelanin blocks hydroxyl radical production by Fenton's reaction, in a dose-dependent manner Neuromelanin also inhibited the iron-mediated oxidation of ascorbic acid, thus sparing this major antioxidant molecule in brain The protective effect of neuromelanin on ascorbate oxidation occurs even in conditions of iron overload into neuromelanin The blockade of iron into a stable iron-neuromelanin complex prevents dopamine oxidation, inhibiting the formation of neurotoxic dopamine quinones The above processes occur intraneuronally in aging and PD, thus showing that neuromelanin is neuroprotective The iron-neuromelanin complex is completely decomposed by hydrogen peroxide and its degradation rate increases with the amount of iron bound to neuromelanin This occurs in PD when extraneuronal iron-neuromelanin is phagocytosed by microglia and iron-neuromelanin degradation releases reactive/toxic iron