University of Johannesburg

About: University of Johannesburg is a education organization based out in Johannesburg, South Africa. It is known for research contribution in the topics: Population & Tourism. The organization has 8070 authors who have published 22749 publications receiving 329408 citations. The organization is also known as: UJ.

ATLAS b-jet identification performance and efficiency measurement with tt¯ events in pp collisions at √s = 13 TeV

Abstract: The algorithms used by the ATLAS Collaboration during Run 2 of the Large Hadron Collider to identify jets containing b-hadrons are presented. The performance of the algorithms is evaluated in the s ...

A new epirubicin biosensor based on amplifying DNA interactions with polypyrrole and nitrogen-doped reduced graphene: Experimental and docking theoretical investigations

Abstract: Epirubicin is an effective anticancer drug, but naturally causes several side effects. Hence the determination of this drug in biological samples, plays a key role in evaluating its effects and side effects. In this research, a novel label-free DNA-based biosensor was fabricated for the analysis of epirubicin in biological samples. The sensor was fabricated through modifying a pencil graphite electrode with polypyrrole, nitrogen doped reduced graphene (for improving the electrical conductivity) and salmon sperm ds-DNA (PP/NrG/ds-DNA/PGE) and the changes in the electrode signal were used for the determination of epirubicin. The PP/NrG/ds-DNA/PGE showed a high sensitivity for epirubicin in the concentration range of 0.004–55.0 μM and had a detection limit of 1.0 nM. For further evaluations, the interactions between ds-DNA bases and epirubicin were investigated through a theoretical docking study and the obtained data confirmed the intercalation of epirubicin in the minor grooves of ds-DNA with guanine bases. The PP/NrG/ds-DNA/PGE was used for the analysis of epirubicin in injection and urine samples.

A novel electrochemical epinine sensor using amplified CuO nanoparticles and a n-hexyl-3-methylimidazolium hexafluorophosphate electrode

Abstract: This study suggests a carbon paste electrode modified with CuO nanoparticles and n-hexyl-3-methylimidazolium hexafluorophosphate (CPE/CuO-NPs/HMIPF6) as a powerful tool for the analysis of epinine for the first time. It has been confirmed that CPE/CuO-NPs/HMIPF6 can improve the sensitivity of epinine electro-oxidation and reduce the overvoltage of this drug compared to an unmodified electrode. The CuO nanoparticles are characterized by XRD and TEM methods. The CPE/CuO-NPs/HMIPF6 exhibited a detection limit of 0.2 μM and a dynamic range of 0.7–900 μM for analysis of epinine by the square wave voltammetric method. Epinine determination was performed successfully by CPE/CuO-NPs/HMIPF6 in serum and urine samples.

Performance of missing transverse momentum reconstruction with the ATLAS detector using proton-proton collisions at s√ = 13 TeV

Abstract: The performance of the missing transverse momentum ( ETmiss ) reconstruction with the ATLAS detector is evaluated using data collected in proton-proton collisions at the LHC at a centre-of-mass energy of 13 TeV in 2015. To reconstruct ETmiss , fully calibrated electrons, muons, photons, hadronically decaying τ-leptons , and jets reconstructed from calorimeter energy deposits and charged-particle tracks are used. These are combined with the soft hadronic activity measured by reconstructed charged-particle tracks not associated with the hard objects. Possible double counting of contributions from reconstructed charged-particle tracks from the inner detector, energy deposits in the calorimeter, and reconstructed muons from the muon spectrometer is avoided by applying a signal ambiguity resolution procedure which rejects already used signals when combining the various ETmiss contributions. The individual terms as well as the overall reconstructed ETmiss are evaluated with various performance metrics for scale (linearity), resolution, and sensitivity to the data-taking conditions. The method developed to determine the systematic uncertainties of the ETmiss scale and resolution is discussed. Results are shown based on the full 2015 data sample corresponding to an integrated luminosity of 3.2fb-1 .