4621. Design and evaluation of a compact photocatalytic reactor for water treatmentMarko Kete, Olena Pliekhova, Lev Matoh, Urška Lavrenčič Štangar, 2017, original scientific article Keywords: Photocatalysis, Photocatalytic ozonation, TiO2, Al2O3 monolith, LAS, PBIC, Reactive blue 19, Phenol
Published in RUNG: 24.08.2017; Views: 4815; Downloads: 0
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4623. Role of Surface Cu-O-Zr Sites in the Photocatalytic Activity of TiO2 Nanoscale ParticlesOlena Pliekhova, Iztok Arčon, Nataša Novak Tušar, Urška Lavrenčič Štangar, 2016, published scientific conference contribution abstract Keywords: Photocatalysis, Titanium dioxide, Copper, Zirconia, co-doping, EXAFS, XANES
Published in RUNG: 23.08.2017; Views: 4690; Downloads: 0
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4626. Biotransformation of copper oxide nanoparticles by the pathogenic fungus Botrytis cinereaEva Kovačec, Marjana Regvar, Johannes Teun van Elteren, Iztok Arčon, Tamás Papp, Darko Makovec, Katarina Vogel-Mikuš, 2017, original scientific article Abstract: Two plant pathogenic fungi, Botrytis cinerea and Alternaria alternata, isolated from crop plants, were
exposed to Cu in ionic (Cu2þ), microparticulate (MP, CuO) or nanoparticulate (NP, Cu or CuO) form, in
solid and liquid culturing media in order to test fungal response and toxic effects of the mentioned
compounds for the potential use as fungicides. B. cinerea has shown pronounced growth and lower levels
of lipid peroxidation compared to A. alternata. Its higher resistance/tolerance is attributed mainly to
biotransformation of CuO and Cu NPs and CuO MPs into a blue compound at the fungal/culturing media
interface, recognized by Cu K-edge EXAFS analysis as Cu-oxalate complex. The pronounced activity of
catechol-type siderophores and organic acid secretion in B. cinerea induce leaching and mobilization of
Cu ions from the particles and their further complexation with extracellularly secreted oxalic acid. The
ability of pathogenic fungus to biotransform CuO MPs and NPs hampers their use as fungicides. However
the results show that B. cinerea has a potential to be used in degradation of Cu(O) nanoparticles in
environment, copper extraction and purification techniques.
Keywords: copper, metal oxide nanoparticles, detoxification mechanisms, metal pollution, Cu-oxalate
Published in RUNG: 23.08.2017; Views: 4368; Downloads: 0
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4627. Edge profiles in K shell photoabsorption spectra of gaseous hydrides of 3p elements and homologuesRobert Hauko, Jana Padežnik Gomilšek, Alojz Kodre, Iztok Arčon, Giuliana Aquilanti, original scientific article Abstract: Photoabsorption spectra of gaseous hydrides of 3p elements (PH3, H2S, HCl) are measured in the energy region of
photoexcitations pertaining to K edge. The analysis of the edge profile is extended to hydrides of 4p series (GeH4,
AsH3, H2Se, HBr) from an earlier experiment, and to published spectra of 2p hydrides (CH4, NH3, H2O, HF) and
noble gases Ar, Kr and Ne and SiH4. The edge profiles are modelled with a linear combination of lorentzian
components, describing excitations to individual bound states and to continuum. Transition energies and
probabilities are also calculated in the non-relativistic molecular model of the ORCA code, in good agreement
with the experiment. Edge profiles in the heavier homologues are closely similar, the symmetry of the molecule
governs the transitions to the lowest unoccupied orbitals. In 2p series the effect of the strong nuclear potential
prevails. Transitions to higher, atomic-like levels remain very much the same as in free atoms.
Keywords: X-ray absorption spectra, gaseous hydrides, 3p K-edge spectra, DFT
Published in RUNG: 23.08.2017; Views: 3668; Downloads: 0
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4628. Electrochemical dissolution of iridium and iridium oxide particles in acidic media : transmission electron microscopy, electrochemical flow cell coupled to inductively coupled plasma mass spectrometry and X-ray absorption spectroscopy studyPrimož Jovanovič, Nejc Hodnik, Francisco Ruiz-Zepeda, Iztok Arčon, Barbara Jozinović, Milena Zorko, Marjan Bele, Martin Šala, Vid Simon Šelih, Samo B. Hočevar, Miran Gaberšček, 2017, original scientific article Abstract: Iridium based particles as the most promising proton exchange membrane electrolyser electrocatalysts were investigated
by transmission electron microscopy (TEM), and by coupling of electrochemical flow cell (EFC) with online inductively
coupled plasma mass spectrometer (ICP-MS). Additionally, a thin-film rotating disc electrode (RDE), an identical location transmission
and scanning electron microscopy (IL-TEM and IL-SEM) as well as an X-ray absorption spectroscopy (XAS) studies have
been performed. Extremely sensitive online time-and potential-resolved electrochemical dissolution profiles revealed that iridium
particles dissolved already well below oxygen evolution reaction (OER) potentials, presumably induced by iridium surface oxidation
and reduction processes, also referred to as transient dissolution. Overall, thermally prepared rutile type IrO2 particles (T-IrO2)
are substantially more stable and less active in comparison to as prepared metallic (A-Ir) and electrochemically pretreated (E-Ir)
analogues. Interestingly, under OER relevant conditions E-Ir particles exhibit superior stability and activity owing to the altered
corrosion mechanism where the formation of unstable Ir(>IV) species is hindered. Due to the enhanced and lasting OER performance,
electrochemically pre-oxidized E-Ir particles may be considered as the electrocatalyst of choice for an improved low temperature
electrochemical hydrogen production device, namely a proton exchange membrane electrolyser.
Keywords: Iridium Oxide Par-ticles, Electrochemical Dissolution of Iridium, Ir L3-edge XANES
Published in RUNG: 23.08.2017; Views: 3902; Downloads: 0
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4629. DEHYDROEPIANDROSTERONE SULFATE CLAWS CONCENTRATIONS IN DOGS FROM BIRTH TO 30 DAYS OF AGE: PRELIMINARY RESULTS.Jasmine Fusi, Marta Montillo, Barbara Bolis, Alessandro Rota, Tanja Peric, Maria Cristina Veronesi, 2017, published scientific conference contribution abstract Abstract: Similarly to all other species, also in the dog improvements in the knowledge on perinatology are mandatory for a better management of newborns, mainly aimed to reduce the impact of perinatal mortality. However, until recently, the study of canine perinatology was limited mainly because of the invasiveness of many investigation procedures, such as repeated blood sampling. In recent times, the claws/nails were proved to be a useful, non invasive, matrix for long time-frame retrospective hormone concentrations analysis also in babies and puppies [1,2], providing a suitable matrix for perinatal long-term hormonal changes studies. The last intrauterine foetal stage of development and the neonatal period represent the most challenging phases for the mammals offspring. It was demonstrated that the activation of the fetal hypothalamic-pituitary-adrenal (HPA) axis leads to dehydroepiandrosterone (DHEA) and DHEA sulfate (DHEA-S) secretion, the major fetal steroids. Thus, DHEA-S measured at birth in newborns could be considered as a marker of offspring HPA axis activity, under the maternal influence. This study was aimed to assess the DHEA-S concentrations in newborn puppies claws, collected at birth and at 30 days of age, and to evaluate the possible influence of age, gender and type of birth on DHEA-S claws accumulation. The study was performed on 58 large purebred, normal, healthy, viable (Apgar≥7) puppies, 31 males and 27 females, born by vaginal spontaneous (N=22) or caesarean (N=36) parturition. DHEA-S was analysed by RIA. The mean ± SD DHEA-S claws concentration significantly (p<0.01) decreased from birth (210±152.00 pg/mg) to 30 days (91±72.63 pg/mg), evidencing the higher fetal DHEA-S secretion in the last fetal stage of pregnancy in comparison to the first postnatal month of age. According to the type of parturition, higher (p<0.001) DHEA-S claws concentrations were found at birth in puppies born by spontaneous than caesarean parturition (300±167.05 vs 154±112.23 pg/mg, respectively); this finding deserves further investigations. No influence of newborn gender was found. Claws DHEA-S values at birth were a bit higher, but with a lower SD, in comparison to data reported for babies 1-3 weeks old [1]. The trend of decrease is in agreement with data reported for cortisol [2] in dead puppies, and suggests, beside the role of cortisol, the important effects of DHEA-S around the time of birth, also in puppies, as reported for babies [1].
[1] Tegethoff et al. Dehydroepindrosterone in nails of infants: a potential biomarker of intrauterine responses to maternal stress. Biological psychology, 87: 414-420, 2011. [2] Veronesi et al. Coat and claws as new matrices for noninvasive long-term cortisol assessment in dogs from birth up to 30 days of age. Theriogenology, 84: 791-796, 2015.
Keywords: DHEA-S, claw, dog
Published in RUNG: 22.08.2017; Views: 4196; Downloads: 0
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