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61.
Exploring element accumulation patterns of a metal excluder plant naturally colonizing a highly contaminated soil
Sara Pignattelli, Ilaria Colzi, Lorenzo Cecchi, Miluscia Arnetoli, Roberto Monnanni, Roberto Gabbrielli, Cristina Gonnelli, 2012, izvirni znanstveni članek

Opis: This work investigates the element distribution in Silene paradoxa growing on the mine dump of Fenice Capanne (Tuscany, Italy). The accumulation of As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn in root apoplast and symplast and in shoot was assessed and compared to the levels of the same metals in the respective rizosphere soils, analyzing both the total and the phytoavailable fractions. Levels of As, Cu, Fe, Pb and Zn, were above toxicity thresholds in both soil and shoot samples. Inter- and intra-element correlations were analyzed in plant and soil using different statistical methods. Soil total and phytoavailable metal concentration were shown not to be dominant in determining metal accumulation by the plant, since no significant positive correlation was found between metal concentration in soils and plants. Moreover, results indicated that S. paradoxa was able to cope with the studied multi-metal contaminated soil excluding the elements from its tissues and preferentially accumulating them into the root compartment, thus suggesting this species as possible good candidate for phytostabilization purposes.
Ključne besede: Metals, Mine dump, Phytostabilization, Silene paradoxa, Compositional data analysis
Objavljeno v RUNG: 20.04.2020; Ogledov: 2733; Prenosov: 0
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62.
A multielement analysis of Cu induced changes in the mineral profilesof Cu sensitive and tolerant populations of Silene paradoxa L.
Sara Pignattelli, Ilaria Colzi, Antonella Buccianti, Ilenia Cattani, Gian Maria Beone, Henk Schat, Cristina Gonnelli, 2013, izvirni znanstveni članek

Opis: tThis work investigates the Cu induced changes in element profiles in contrasting ecotypes of Silene para-doxa L. A metallicolous copper tolerant population and a non-metallicolous sensitive population weregrown in hydroponics and exposed to different CuSO4treatments. Shoot and root concentrations of Ca,Cu, Fe, K, Mg, Mn, Mo, Na, P, S and Zn were evaluated through ICP-OES.Results indicated that increasing the environmental Cu concentration had a population dependenteffect on element profiles, shoot-to-root ratios and correlations among the elements. Generally, in thetolerant population Cu treatment induced a higher element accumulation in roots and had minimaleffects on the shoot element profile, thus resulting in a progressively decreasing shoot-to-root ratio foreach element. In the sensitive population element concentrations in root and shoot were much moreaffected and without a consistent trend. Copper treatment also affected the correlations between theelements, both in roots and shoots of the two populations, but more so in the sensitive population thanin the tolerant one. Thus, Cu exposure strongly disturbed element homeostasis in the sensitive population,but barely or not in the tolerant one, probably mainly due to a higher capacity to maintain proper rootfunctioning under Cu exposure in the latter. Differences in element profiles were also observed in theabsence of toxic Cu exposure. These differences may reflect divergent population-specific adaptations todifferential nutrient availability levels prevailing in the populations’ natural environments. There is noevidence of inherent side-effects of the Cu tolerance mechanism operating in the tolerant population.
Ključne besede: Mineral profile, Copper tolerance, Silene paradoxa, Compositional data analysis
Objavljeno v RUNG: 20.04.2020; Ogledov: 2776; Prenosov: 0
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63.
Improved photocatalytic activity of anatase-rutile nanocomposites induced by low-temperature sol-gel Sn-modification of TiO2
Ksenija Maver, Iztok Arčon, Urška Lavrenčič Štangar, Mattia Fanetti, Saim Emin, Matjaž Valant, 2020, izvirni znanstveni članek

Opis: The Sn-modified TiO2 photocatalysts are prepared by low-temperature sol-gel processing based on organic titanium and tin precursors with varied Sn concentrations (from 0.1–20 mol .%). The role of Sn dopant as the promotor of the formation of TiO2 rutile crystalline phase is explained and the optimal Sn concentration for preparation of efficient Sn-modified titania photocatalyst is determined. Up to 40 % increase in photocatalytic activity is achieved in Sn-modified TiO2 photocatalytic thin films dried at 150 °C with low Sn concentrations in the range from 0.1 to 1 mol .%. At low Sn concentrations optimal ratio between anatase and rutile (nano)crystals is obtained, which facilitates charge separation at the TiO2 photocatalyst’s surface. When the concentration of Sn increases above 5 mol.% or when the films are calcined at 500 °C, the relative amount of rutile phase with inferior photocatalytic activity, increases and the nanocrystals of titania grow, leading to fewer active sites per unit mass and the reduction of activity in comparison to unmodified TiO2.
Ključne besede: Anatase-rutile Sn-modified TiO2 XAS analysis Photocatalytic activity
Objavljeno v RUNG: 10.02.2020; Ogledov: 2948; Prenosov: 0
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64.
Quality Control of Purified Proteins to Improve Research Data Reproducibility
Stephan Uebel, Ario De Marco, Nick Berrow, Mario Lebendiker, Maria Garcia-Alai, Stefan Knauer, Blanca Lopez-Mendez, Andrea Matagne, Annabel Parret, Kim Remans, Bertrand Raynal, 2019, objavljeni povzetek znanstvenega prispevka na konferenci (vabljeno predavanje)

Ključne besede: protein quality, biophysical analysis, aggregation
Objavljeno v RUNG: 15.01.2020; Ogledov: 2505; Prenosov: 0
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65.
Determination of Iron in Environmental Water Samples by FIA-TLS
Miha Tomšič, Leja Goljat, Hanna Budasheva, Dorota Korte, Arne Bratkič, Mladen Franko, 2019, izvirni znanstveni članek

Opis: The determination of low concentration of iron in natural waters can be difficult due to the complexity of natural water, but primarily because it requires preconcentration of the sample with solvent extraction. In this work we report on results of thermal lens spectrometry (TLS) coupled to flow injection analysis (FIA) as a highly sensitive FIA-TLS method of iron detection. The concentration of iron redox species was determined using 1,10-phenanthroline (PHN), that forms stable complexes with Fe(II) ions which are characterized by an absorption maximum at 508 nm. The TLS system using a 633 nm probe laser and 530 nm pump laser beam was exploited for on-line detection in flow injection analysis, where a PHN solution was used as the carrier solution for FIA. The concentration of the complexing agent affects the quality of the TLS signal, and the optimal concentration was found at 1 mM PHN. The achieved limits of detection (LODs) for Fe(II) and total iron were 33 nM for Fe(II) and 21 nM for total iron concentration. The method was further validated by determining the linear concentration range, specificity in terms of analytical yield and by determining concentration of iron in a water sample from a local water stream.
Ključne besede: Flow injection analysis, iron concentration, thermal lens spectroscopy
Objavljeno v RUNG: 18.12.2019; Ogledov: 3170; Prenosov: 105
.pdf Celotno besedilo (690,39 KB)

66.
A cellular network database for fingerprint positioning systems
Donatella Gubiani, Paolo Gallo, Andrea Viel, Andrea Dalla Torre, Angelo Montanari, 2019, objavljeni znanstveni prispevek na konferenci

Opis: Besides being a fundamental infrastructure for communication, cellular networks are increasingly exploited for positioning via signal fingerprinting. Here, we focus on cellular signal fingerprinting, where an accurate and comprehensive knowledge of the network is fundamental. We propose an original multilevel database for cellular networks, which can be automatically updated with new fingerprint measurements and makes it possible to execute a number of meaningful analyses. In particular, it allows one to monitor the distribution of cellular networks over countries, to determine the density of cells in different areas, and to detect inconsistencies in fingerprint observations.
Ključne besede: Cellular network, Signal fingerprinting, Multilevel database, Data analysis
Objavljeno v RUNG: 17.09.2019; Ogledov: 3304; Prenosov: 0
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67.
HOLISTIC GEOMORPHOLOGICAL SPATIAL ANALYSIS OF KARST ON KRK ISLAND
Ela Šegina, 2019, doktorska disertacija

Opis: The intriguing spatial variability of surface features on Krk Island has stimulated the research of this karst area located in the coastal zone of the Dinaric karst in Croatia. Field inspection, ortho-rectified aerial photos (0.5m resolution) and a topographic map (1:5,000) were used for the detection and delineation of detectable karst surface features appearing on the island with the area of 405.5 km². This method resulted in the identification of several yet undefined types of surface features occurring on karst, requiring the revision of the existing classification and re-establishment of a new classification system compatible with the particular field reality. Several morphologic and distributive parameters that had been calculated for each re-classified type of surface feature provided insight into the surface features elementary characteristics, their spatial variability and the correlation to the other types of surface features and to the recent karst relief. This analysis based on a large, accurate dataset, contributed to the general knowledge on karstic surface features, the conditions of surface features in Dinaric karst and to the understanding of the karst surface evolution on Krk Island.
Ključne besede: karst geomorphology, GIS, spatial analysis, Krk Island, Dinaric karst, Adriatic Sea
Objavljeno v RUNG: 13.09.2019; Ogledov: 4545; Prenosov: 217
.pdf Celotno besedilo (17,12 MB)

68.
Capturing and Storing Exhaled Breath for Offline Analysis
Iain R. White, Stephen J Fowler, 2019, samostojni znanstveni sestavek ali poglavje v monografski publikaciji

Opis: In this chapter we will summarize and discuss methods for the capture and storage of exhaled breath, prior to offline (and indirect online) analysis. We will detail and compare methods currently in use, including their applications, key strengths, and limitations. In synthesizing the best features of each technique, we will propose an ideal standardized breath sampling solution, and give a personal vision on the next steps to be taken in this exciting area of breath research.
Ključne besede: Breath analysis, Breath sampling, Offline analysis, Thermal desorption, Gas chromatography-mass spectrometry
Objavljeno v RUNG: 22.07.2019; Ogledov: 3291; Prenosov: 0
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69.
Exhaled breath metabolomics reveals a pathogen-specific response in a rat pneumonia model for two human pathogenic bacteria: a proof-of-concept study
Pouline M van Oort, Iain R. White, 2019, izvirni znanstveni članek

Opis: 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.
Ključne besede: biomarkers, exhaled breath analysis, infection, pneumonia
Objavljeno v RUNG: 22.07.2019; Ogledov: 3015; Prenosov: 0
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70.
Mass composition of ultra-high energy cosmic rays at the Pierre Auger Observatory
Gašper Kukec Mezek, 2019, doktorska disertacija

Opis: 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.
Ključne besede: astroparticle physics, ultra-high energy cosmic rays, extensive air showers, mass composition, Pierre Auger Observatory, machine learning, multivariate analysis
Objavljeno v RUNG: 03.04.2019; Ogledov: 4824; Prenosov: 185
.pdf Celotno besedilo (17,53 MB)

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