71. Exhaled breath metabolomics reveals a pathogen-specific response in a rat pneumonia model for two human pathogenic bacteria: a proof-of-concept studyPouline M van Oort, Iain R. White, 2019, original scientific article Abstract: Volatile organic compounds in breath can reflect host and pathogen metabolism and might be used to diagnose pneumonia. We hypothesized that rats with Streptococcus pneumoniae (SP) or Pseudomonas aeruginosa (PA) pneumonia can be discriminated from uninfected controls by thermal desorption-gas chromatography-mass-spectrometry (TD-GC-MS) and selected ion flow tube-mass spectrometry (SIFT-MS) of exhaled breath. Male adult rats (n = 50) received an intratracheal inoculation of 1) 200 µl saline, or 2) 1 × 107 colony-forming units of SP or 3) 1 × 107 CFU of PA. Twenty-four hours later the rats were anaesthetized, tracheotomized, and mechanically ventilated. Exhaled breath was analyzed via TD-GC-MS and SIFT-MS. Area under the receiver operating characteristic curves (AUROCCs) and correct classification rate (CCRs) were calculated after leave-one-out cross-validation of sparse partial least squares-discriminant analysis. Analysis of GC-MS data showed an AUROCC (95% confidence interval) of 0.85 (0.73-0.96) and CCR of 94.6% for infected versus noninfected animals, AUROCC of 0.98 (0.94-1) and CCR of 99.9% for SP versus PA, 0.92 (0.83-1.00), CCR of 98.1% for SP versus controls and 0.97 (0.92-1.00), and CCR of 99.9% for PA versus controls. For these comparisons the SIFT-MS data showed AUROCCs of 0.54, 0.89, 0.63, and 0.79, respectively. Exhaled breath analysis discriminated between respiratory infection and no infection but with even better accuracy between specific pathogens. Future clinical studies should not only focus on the presence of respiratory infection but also on the discrimination between specific pathogens.
Keywords: biomarkers, exhaled breath analysis, infection, pneumonia
Published in RUNG: 22.07.2019; Views: 3068; Downloads: 0
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72. Mass composition of ultra-high energy cosmic rays at the Pierre Auger ObservatoryGašper Kukec Mezek, 2019, doctoral dissertation Abstract: Cosmic rays with energies above 10^18 eV, usually referred to as ultra-high energy cosmic rays (UHECR), have been a mystery from the moment they have been discovered. Although we have now more information on their extragalactic origin, their direct sources still remain hidden due to deviations caused by galactic magnetic fields. Another mystery, apart from their production sites, is their nature. Their mass composition, still uncertain at these energies, would give us a better understanding on their production, acceleration, propagation and capacity to produce extensive air showers in the Earth's atmosphere. Mass composition studies of UHECR try to determine their nature from the difference in development of their extensive air showers.
In this work, observational parameters from the hybrid detection system of the Pierre Auger Observatory are used in a multivariate analysis to obtain the mass composition of UHECR. The multivariate analysis (MVA) approach combines a number of mass composition sensitive variables and tries to improve the separation between different UHECR particle masses. Simulated distributions of different primary particles are fitted to measured observable distributions in order to determine individual elemental fractions of the composition. When including observables from the surface detector, we find a discrepancy in the estimated mass composition between a mixed simulation sample and the Pierre Auger data. Our analysis results from the Pierre Auger data are to a great degree independent on hadronic interaction models. Although they differ at higher primary masses, the different models are more consistent, when combining fractions of oxygen and iron. Compared to previously published results, the systematic uncertainty from hadronic interaction models is roughly four times smaller. Our analysis reports a predominantly heavy composition of UHECR, with more than a 50% fraction of oxygen and iron at low energies. The composition is then becoming heavier with increasing energy, with a fraction of oxygen and iron above 80% at the highest energies.
Keywords: astroparticle physics, ultra-high energy cosmic rays, extensive air showers, mass composition, Pierre Auger Observatory, machine learning, multivariate analysis
Published in RUNG: 03.04.2019; Views: 4918; Downloads: 186
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73. Cu and Zr surface sites in photocatalytic activity of TiO [sub] 2 nanoparticles : the effect of Zr distributionOlena Pliekhova, O. L. Pliekhov, Mattia Fanetti, Iztok Arčon, Nataša Novak Tušar, Urška Lavrenčič Štangar, 2019, original scientific article Abstract: The present work is focused on the role of ZrO2 modification in the performance of CuO modified TiO2. Zirconia
loading leads to formation of more resistant photocatalytic layers compared to samples modified with only
copper containing species. Surface modification of mixed phase TiO2 with CuO/ZrO2 improves the degradation
of Reactive blue 19 dye under simulated solar irradiation. An in-depth investigation of the catalysts showed that
in case of CuO/ZrO2 modification, the covering of the TiO2 surface with zirconium containing species prevents
morphological and harmful energetic changes induced by copper species formed on the rutile TiO2 phase at a
higher copper loading.
Keywords: titanium dioxide, surface modification, XAS analysis, surface acidity, Hammett indicators
Published in RUNG: 26.03.2019; Views: 3187; Downloads: 0
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77. IETI, Isogeometric Tearing and InterconnectingStefan K. Kleiss, Clemens Pechstein, Bert Jüttler, Satyendra Tomar, 2012, original scientific article Keywords: isogeometric analysis, NURBS, domain decomposition, FETI, IETI
Published in RUNG: 13.11.2018; Views: 3134; Downloads: 0
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78. Volatile and sensory profiling of Shiraz wine in response to alcohol management: comparison of harvest timing versus technological approachesRocco Longo, John W. Blackman, Guillaume Antalick, Peter J. Torley, Suzy Y. Rogers, Leigh Schmidtke, 2018, original scientific article Keywords: Common Component Specific Weights Analysis, polypropylene membrane, sensory descriptive analysis, sequential harvest, volatiles, wine alcohol-reduction
Published in RUNG: 17.09.2018; Views: 3396; Downloads: 0
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79. A comparative study of partial dealcoholisation versus early harvest: Effects on wine volatile and sensory profilesRocco Longo, John.W Blackman, Guillaume Antalick, Peter J. Torley, Suzy.Y Rogers, Leigh Schmidtke, 2018, original scientific article Keywords: Common component and specific weights analysis, Dealcoholisation, Early harvest, Evaporative perstraction, Lower alcohol wine, Reverse osmosis, Sensory descriptive analysis, Wine
Published in RUNG: 17.09.2018; Views: 3450; Downloads: 0
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