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51.
Diagnostic and prognostic markers in canine inflammatory and neoplastic head and neck conditions
Ana Rejec, 2015, doktorska disertacija

Opis: Several different types of conditions with inflammatory and neoplastic background affect the anatomical localities of the head and neck in a dog. It is a well-recognized fact that these conditions affect the quality of life, as they are associated with various degree of regional dysfunction, have systemic effects and can be direct or indirect cause of death. Unfortunately, many dogs with both inflammatory and neoplastic head and neck conditions are presented at an advanced stage of the disease which can have significant impact on treatment strategies. The identification of biomarkers is advisable to enhance effective staging, grading and prognostication, which will in turn more accurately direct recommendations for therapy. These biomarkers can theoretically help to distinguish between inflammatory and neoplastic conditions, justify the management of patients more accurately and potentially predict the prognosis and the survival of patients. It was our interest to investigate the diagnostic and prognostic value of complete blood count parameters and indices in dogs with head and neck conditions of inflammatory and neoplastic origin, regulatory T cells in dogs with periodontal disease, immunohistochemical (Ki-67 and VEGFR-2) and histopathological biomarkers in dogs with inflammatory and neoplastic head and neck conditions and to evaluate the effectiveness of an accelerated radiotherapy protocol for the treatment of advanced canine HNSCC. We have proved that the parameters investigated might serve as important supportive diagnostic and/or prognostic biomarkers which might help to improve the treatment strategies of both inflammatory and neoplastic head and neck conditions in dogs and that the accelerated chemoradiotherapy protocol represents an effective alternative treatment option for dogs with advanced HNSCC.
Ključne besede: biomarkers, dogs, periodontal disease, regulatory T cells, head and neck tumours, complete blood count, radiotherapy, vascular endothelial growth factor receptor 2
Objavljeno: 26.11.2015; Ogledov: 1186; Prenosov: 18
.pdf Polno besedilo (59,54 MB)

52.
Aspects of micro black hole evaporation
Saeede Nafooshe, 2015, doktorska disertacija

Ključne besede: micro black holes, evaporation, gravitons, grey-body factors, large dimensions, quasi-normal modes, Vaidya metric
Objavljeno: 17.11.2015; Ogledov: 1468; Prenosov: 87
.pdf Polno besedilo (3,14 MB)

53.
On the Optionality of Wh-Fronting in a Multiple Wh-Fronting Language
Petra Mišmaš, 2015, doktorska disertacija

Opis: This thesis explores the fact that in Slovenian multiple wh-questions not all wh-phrases have to front. This suggests that multiple wh-movement in Slovenian is optional. The majority of the existing literature on multiple wh-fronting focuses on questions in which all wh-phrases have to move to clause initial positions, I, on the other hand, focus on optionality in multiple wh-questions. I show movement in Slovenian is not avoided because of phonological, syntactic or semantic restrictions that influence other languages (cf. Bošković 2002), and that the Principle of Distinctness (Richards 2010) does not account for all cases of optional multiple wh-fronting in Slovenian. Three types of multiple wh-questions in Slovenian are determined and analyzed: (i) questions in which all wh-phrases move to clause initial positions (i.e. questions with multiple wh-fronting), (ii) questions in which one wh-phrase has to be moved to a clause initial position and the rest undergo movement to a clause internal position (multiple wh-questions with short movement), (iii) questions in which at least one wh-phrase has to be moved to a clause initial position and the rest stay in situ (multiple wh-questions with wh-in-situ). Crucially, in all three types at least one wh-phrase has to move to a clause initial position for a question to receive a true question reading. I assume the Cartographic approach and propose an account of multiple wh-fronting in Slovenian in which one wh-phrase has to move to an Interrogative Projection (the clause initial position) in the Left Periphery while the remaining wh-phrases move to Wh-Projections in the Left Periphery, questions in (i), or the Low Periphery, questions in (ii). I propose that wh-phrases with a wh-feature undergo wh-movement, which means that wh-movement is in fact obligatory in Slovenian. In questions of type (iii), wh-phrases that do not undergo movement are in fact bare wh-pronouns, which one also finds in polarity contexts, that are licensed by the interpretable Q+wh-feature located in the Interrogative Projection. Because the bare wh-pronouns do not come with a wh-feature, they do not have to move. I conclude that wh-movement in Slovenian only appears to be optional.
Ključne besede: multiple wh-fronting, short movement, optionality, Interrogative Projection, Left Periphery, Low Periphery, bare wh-pronouns, wh-in-situ
Objavljeno: 10.11.2015; Ogledov: 1900; Prenosov: 107
.pdf Polno besedilo (1,43 MB)

54.
EXPLORING BIODIVERSITY POTENTIAL OF WINE ASSOCIATED YEASTS
Sofia Dashko, 2015, doktorska disertacija

Opis: Human exploitation of yeast fermentation dates back to the Neolithic. S. cerevisiae has been the most important yeast used for numerous fermentations of biotechnological interest, including grape fermentation for wine production. Despite its abundant use, the molecular mechanisms controlling alcoholic fermentation are rather unclear and the choice of S. cerevisiae as an inoculum is often the consequence of a mere habit, rather than the result of rational analyses. In this work we focused on the role of different yeasts in the winemaking process. I was interested in understanding how the specific strain used for inoculum could influence the wine aroma formation. Furthermore, I wished to investigate the yeast genetics and ecology by characterizing their population and strain diversity in one of the wine regions of Slovenia. To evaluate the effect of the yeast species on the fermentation outcome, we performed successive fermentations with five different species in combination with the industrial strain S. cerevisiae Lalvin T73. The experiment showed that at least two more yeast species, Kazachstania gamospora and Zygosaccharomyces kombuchaensis have good potential to be applied in the winemaking. , The main conclusions of this study are the possibility of: i) expanding the palette of alternative starters to widen the aromatic components ii) co–fermenting using two different yeast species. Mixed yeast culture fermentations are present in the natural context, but this practice has been neglected in biotechnological processes. Positive results of wine fermentations with non – conventional yeast urged us to explore the diversity of Slovenian wine region natural isolates. The resulting yeast collection counts more than 1200 strains for which phenotype and genotype have been defined. Numerous isolates, including non – Saccharomyces species, showed promising oenological and biotechnological traits because of their capacity of rapid utilization of various carbon sources, growth at low pH and at presence of copper sulfite and potassium metabisulfite. Sampling also revealed sharp discrimination between the ecological niches of S. cerevisiae and S. paradoxus, which is a striking feature of European vineyards. While S. cerevisiae habitats are strongly associated with human activity, S. paradoxus was mainly isolated from the forest sources. Profound analysis of the collected data could give some explanations to the driving forces of S. cerevisiae domestication and S. paradoxus geographic isolation population structure.
Ključne besede: Yeasts, biodiversity, molecular biology, alcoholic fermentation
Objavljeno: 02.11.2015; Ogledov: 1840; Prenosov: 17
.pdf Polno besedilo (41,27 MB)

55.
Radioactive isotopes in ground waters of Slovenia
Katarina Kovačič, 2015, doktorska disertacija

Opis: Within the duration of three projects (J7-0363, L1-0437, L1-4280), in the period from 2008 to 2013, measurements of tritium (3H), 40K and γ-ray emitters of uranium (238U, 226Ra and 210Pb) and thorium (228Ra and 228Th) decay series in groundwaters of Slovenia were carried out. Tritium was also measured in precipitation at selected locations. Groundwater sampling sites were selected in order to cover the most representative lithological units that are found in Slovenia and were at the same time evenly distributed throughout the country. In total, 281 samples were measured from 120 different locations. Measurements in the period 2009-2013 have shown that tritium concentrations in precipitation in Ljubljana are for about 30% lower compared to those in Vienna, however they are in line with seasonal fluctuations observed in Vienna. This was an important information in the process of the reconstruction of past tritium concentrations in precipitation in Ljubljana (tritium curve) for the missing period between 1953 and 1981. Tritium curve represents the input data when determining the average age of water. In determining the influence of various parameters on the final interpretation of the groundwater age it has been found that the greatest uncertainty contribute the measurements of the tritium curve and the measurements of tritium in groundwater samples. Also, the interaction of other factors (continental effect, rainfall regime, infiltration) and the lack of knowledge of them may have a major impact on the misinterpretation of groundwater age. Based on tritium concentration, groundwaters were divided into 4 major categories, into groundwaters that are older than 100 years (tritium concentration was below the detection limit), groundwaters, where the older component prevails (concentration of tritium was between 0 and 2.5 TU), groundwaters with the age between 30 and 60 years (the concentration of tritium was on average 8 TU) and recent groundwaters with age up to 15 years (tritium concentration of about 6 TU). The natural background of γ-ray emitters was determined for each lithological unit. The most represented radionuclide was 40K with concentrations always above the detection limit. A dependency of 40K concentrations on nitrate was observed, especially in the recharge areas, where limestone prevailed. Other γ-ray emitters revealed some dependence on nitrate concentration, especially both radium isotopes (226Ra and 228Ra). The concentration of 210Pb in groundwaters is mainly due to the connection with the surface and consequently with atmospheric 210Pb. The highest concentrations of 238U and 228Ra were measured in groundwaters from recharge areas in clastic rocks with a clay component. In contrast to the expected, concentrations for all γ-ray emitters (except 210Pb) were the lowest or even not detectable, in groundwaters from recharge areas in igneous and metamorphic rocks. Among γ-ray emitters and categorization based on tritium concentrations, elevated concentrations of 238U were observed in groundwaters with prevailing older component. Elevated concentrations of 40K were also observed in them. The largest scattering of 210Pb and 40K concentrations was observed in recent waters, which indicates a connection with the surface and application of fertilizers.
Ključne besede: Groundwaters, Slovenia, tritium input curve, natural gamma-ray emitters background.
Objavljeno: 05.10.2015; Ogledov: 1395; Prenosov: 41
.pdf Polno besedilo (8,62 MB)

56.
Development of Advanced TiO2/SiO2 Photocatalyst for Indoor Air Cleaning
Andraž Šuligoj, 2015, doktorska disertacija

Opis: TiO2 - SiO2 composites were synthesized by low-temperature sol-gel impregnation method, using four different titania sources (P-25 from Degussa, PC500 from Millennium, CCA 100 AS and CCA 100 BS from Cinkarna, later denoted as AS and BS, respectively) and deposited on aluminium and glass carriers. Ordered and disordered mesoporous silicas were impregnated with ce{TiO2} in powder or suspension form in the Ti : Si molar ratio 1 : 1. Structure, size, band gap, chemical composition and specific surface area of nanoparticles were determined by X-ray diffraction (XRD), scanning (SEM) and transmission electron microscopy (TEM), UV-vis diffuse reflectance spectroscopy (DR-UV-vis), Fourier transform infrared spectroscopy (FT-IR) and ce{N2} physisorption. Additionally, quantity of surface hydroxyl groups, surface acidity and mechanical stability of the coatings were determined by temperature programmed Fourier transform infrared spectroscopy (TPD-IR) and Wolff-Wilborn method, respectively. The photocatalytic activity of TiO2 and TiO2 - SiO2 composites was evaluated in the photodegradation of toluene and formaldehyde, as model VOCs, under UVA light irradiation in lab-made photoreactor system with two different regimes; batch and plug-flow mode. These two VOCs are being considered as examples of two of the six major classes of indoor air contaminants. Adsorption properties of the samples with toluene, have shown that the addition of mesoporous silica was beneficial. The increase of the adsorption of the bare AS TiO2 (9.5 %) was higher in the case of ordered silica, SBA-15 (2.8 times for AS/SBA15 to 26.8 %) than disordered SiO2 KIL-2 (2.4 times for AS/KIL2 to 22.7 %) although it was significant in both types of mesoporous silica supports (over 20 %). Adsorption was found to be dependent mostly on the quantity of surface Si-OH groups. Regarding the photocatalytic activities towards toluene degradation, the results with pure TiO2 showed the fastest kinetics in case of sample AS followed by PC500 and P25. The observed behaviour was ascribed to smaller particle size, and consequently higher specific surface area. Grafting titania onto silica showed the importance of structural parameters. Most importantly, if the pore structure of bare TiO2 collapsed, this resulted in decreased activity. On the other hand, retainment of the pore structure improved the distribution of nanoparticles, crystallinity and optical properties, which resulted in improved photocatalytic activity. In the degradation of formaldehyde, it was found that adsorption and degradation abilities of the materials were much more dependent on the structural properties of the samples, i.e., the pore structure. This was explained as a consequence of the different degradation mechanisms of both pollutants. Toluene degradation is governed by the oxidation through photogenerated holes - direct oxidation, whereas in the degradation of formaldehyde, the major oxidative species are OH radicals. In addition, the same as in toluene oxidation, the activity was dependent mainly on the number of crystal defects and the band gap values, that is the oxidation and reduction potentials of the catalysts. The degradation efficiency was increased from 88 % in pure AS TiO2 to 97 % when this titania was grafted onto colloidal silica (7C). An important highlight of the thesis is synthesis of a novel photocatalyst, labelled AS7C, which comprises an acidic colloidal suspension AS as TiO2 source and colloidal silica, using a low-temperature sol-gel impregnation method. This sample used all the above mentioned properties that improve photocatalytic activity towards both pollutants. Mechanical stability of the samples was also tested. The tests showed that binder, in the form of colloidal SiO2 (in size of 25 nm) in combination with colloidal titania of appropriate size - 6 nm, produced the highest mechanical stability of the coatings, which also showed excellent photocatalytic activity. Stability of the coatings, using AS as titania source, was greatly improved. The Wolff-Wilborn test on AS coating showed no mechanical resistance, while with the optimal (in terms of photocatalytic performance) addition of 7C SiO2 binder stability was excellent (F, which is in the middle of 6B-6H hardness scale). This sample (AS7C) was also tested for release of aerosols, during operation of the reactor, which could be harmful for human health at longer exposure times. It was found that aerosols are formed, probably as a consequence of detachment of nanoparticles in the first period of photodegradation test. However, their formation in consecutive tests was greatly reduced. Last but not least, a pilot plug-flow reactor was constructed to test the photocatalyst's efficiency in one-pass degradation of toluene. Sample AS7C was able to degrade toluene at conditions applied (v= 400 mL/min, m(catalyst) = 1049 mg, C(0) = 1 ppmv), which means that the out-flow from reactor was clean of the pollutant and any possible intermediates, comprising only of humid air and CO2. Deactivation of the catalyst was found at higher air flow and higher initial concentration of the pollutant. However, the concentrations of pollutants in living conditions are few orders of magnitude lower, hence this is a promising result.
Ključne besede: Air remediation, TiO2 photocatalysis, Immobilization, Thin layers, TiO2/SiO2 composites
Objavljeno: 31.08.2015; Ogledov: 1954; Prenosov: 50
.pdf Polno besedilo (33,47 MB)

57.
Biological role of Grapevine fanleaf virus (GFLV) in winegrowing region of Northern Primorska
Anastazija Jež Krebelj, 2015, doktorska disertacija

Opis: Grapevines (Vitis vinifera L.) represent one of the most important crops in the world in terms of both production and economic importance. Grapevines are exposed to many types of abiotic stresses (e.g., drought, flooding, low and high temperature, salinity) and biotic stresses (e.g., viruses, bacteria, phytoplasma, fungal disease) during their life-cycle. Therefore, grapevines elicit the appropriate defence mechanisms. In the first part of this study, we monitored the occurrence of Grapevine fanleaf virus (GFLV) infection, which causes progressive decline of infected grapevines and lowers their yield. Grapevines were also tested for the presence of other viruses important for grapevines: Arabis mosaic virus (ArMV), Grapevine leafroll associated virus (GLRaV)-1, -2, -3, -4, -9, Grapevine virus A (GVA), Grapevine fleck virus (GFkV) in this study; and by Cigoj (2015): Grapevine virus B (GVB), Tomato black ring virus (TBRV), Grapevine chrome mosaic virus (GCMV), Tomato ringspot virus (ToRSV), Raspberry ringspot virus (RpRSV), Strawberry latent ringspot virus (SLRSV), and Tobacco ringspot virus (TRSV). Using ELISA, the presence of the following grapevine viruses were detected: GFLV, (GFkV), (GVA), and Grapevine leafroll associated viruses- 1, -2, -3,. A wide range of GFLV symptoms caused by grapevine fanleaf disease in naturally infected vineyards were observed, including leaf, shoot and cluster malformations and leaf yellowing. GFLV is disseminated by its biological vector X. index, and through vegetative propagation of virus-infected material. The spread of GFLV in the vineyards was investigated here. We constructed a spatio-temporal study of the GFLV titres during the seasons and throughout the grapevine, for its distribution in different grapevine organs through the season. This study shows that young leaves have high virus titres through the whole vegetative period, while mature leaves, tendrils and flower/ berry clusters only have high titres at the beginning of the vegetative period. The seeds retain high virus titres after berry colouring. Phloem scrapings were shown to contain lower virus titres during the vegetative period, with an increase outside and at the beginning of the vegetative period. In flower/ berry clusters, mature leaves and tendrils, the GFLV titres decrease significantly over the vegetative period. Additionally, different GFLV titres were shown in five different cultivars, and different combinations of mixed infections with other grapevine viruses influenced the GFLV titre differently. Finally, correlation between the magnitude of symptom appearance and GFLV titres was analysed. Grapevines adapt to abiotic stresses and biotic stresses by the expression of a wide range of stress-responsive genes, which are thought to have key roles in stress tolerance and survival. SWP of the infected grapevines through the season was lower than SWP measured for healthy grapevines. For both seasons, there were significant differences in SWP measurements between healthy and GFLV-infected grapevines of ‘Schioppettino’ trained using the single Guyot training system. SWP and RHC of the GFLV-infected grapevines were reduced compared to the healthy controls. The water deficit triggered the production of ABA, which induced the expression of the stress-related gene RD22. Additionally, this study shows that the WRKY gene that is involved in the ABA signalling network is regulated by water deficit. Plant defence responses to water stress also included up-regulation of the F3H2 and LDOX genes, which are involved in anthocyanins synthesis. GFLV infection significant impacted upon the expression of genes involves in ABA biosynthesis, as NCED1 and NCED2, and upon two genes involved in the early stages of anthocyanins synthesis, as CHS2 and F3H1. We also showed that the combination of grapevine cultivar, training system, and environmental conditions impacts on gene expression
Ključne besede: Vitis vinifera L., grapevine, Grapevine fanleaf virus, GFLV, grapevine disease, virus titre, distribution, fluctuation, ELISA, qPCR, ABA, drought, water status, water deficit, SWP, RHC, anthocyanins, gene expression
Objavljeno: 27.07.2015; Ogledov: 2208; Prenosov: 73
.pdf Polno besedilo (4,19 MB)

58.
59.
Bi2O3-BASED PYROCHLORE NANOSTRUCTURES AND THEIR CRYSTALLOGRAPHIC, OPTOELECTRONIC AND PHOTOCATALYTIC PROPERTIES
Metka Benčina, 2015, doktorska disertacija

Opis: Bi2O3-based pyrochlore nanomaterials and their photocatalytic, optoelectronic and crystallographic properties are the research topics of this doctoral dissertation. We synthesized these materials at nanoscale, since they are expected to possess photoactivity in the visible-light spectrum, which is an important target for the high-performance photocatalysts. To prepare nanoparticles that are not agglomerated, different synthesis methods (coprecipitation, coprecipitation followed by the digestion, reverse micelle) and post-treatments (furnace or hydrothermal reactor) were examined. Micrometer size materials were prepared with the solid-state reaction and annealing at high temperature. Bi2Ti2O7 nanoparticles were synthesized with the coprecipitation reaction, followed by annealing at 570 °C in the furnace or in the hydrothermal reactor at 230 °C for 18h in NH4OH medium. UV-Vis diffuse reflectance spectra of the Bi2Ti2O7 samples showed that they exhibit the maximum absorption edge at ~420-440 nm. The UV-Vis diffuse reflectance measurements of Bi2Ti2O7 loaded with 10 wt. % of Ag as a co-catalyst showed an enhanced absorbance in the visible region, presumably due to a contribution of Local Surface Plasmon Resonance. The Bi2Ti2O7 nanoparticles are not photocatalytically active under the visible light irradiation without assistance of a sacrificial reagent. The photocatalytic activity does not increase even with Ag as a co-catalyst under visible light irradiation. All samples are active under UV light irradiation, especially the sample with Ag that is able to decolourize 7 mg/L of metyl orange in just 3 min of exposure to UV light. However, H2O2 as a sacrificial reagent increases the photocatalytic activity of Bi2Ti2O7 under visible light irradiation. Phase pure pyrochlore Bi1.647Nb1.118Fe1.157O7 (BNF) nanoparticles were synthesized with coprecipitation reaction and further annealing in the furnace at 570 °C for 7h or 15h and in the hydrothermal reactor at 160 °C for 18h in 3 M or 6 M NaOH medium. The BNF materials exhibit shift toward longer wavelengths in absorbance of visible light (up to ~550-650 nm). This result confirmed that incorporation of Fe in the pyrochlore structure decreases the band gap. The BNF nanoparticles annealed for 7h showed intense photoactivity under visible light irradiation in the presence of a sacrificial reagent. The improved photoactivity, much better than with BNF, was shown for the composite nanoparticles BiOCl/BNF. They decolourize 100 % of the 7 mg/L methyl orange within only 2h of the visible light irradiation in the presence of H2O2. Phase pure pyrochlore Bi1.9Te0.58Fe1.52O6.87 (BTF) nanoparticles were synthesised by coprecipitation reaction and further annealing in the furnace at 570 °C for 7h. Although the BTF nanoparticles include higher amount of Fe than BNF nanoparticles and exhibit narrower band gap, the photoactivity of these nanoparticles is a bit lower than that of BNF nanoparticles. We assume that Fe at some critical concentration causes formation of mid-band states, which act as recombination centers. The same as BiOCl/BNF, the BiOCl/BTF composite is able to decolourize 100 % of the 7 mg/L MO within 2h of the visible light irradiation in the presence of H2O2. Based on the band gap determination and estimation of valence and conduction band levels, the proposed photodecolourization mechanisms are discussed. The conduction band levels of all synthesized materials lie more positively than O2/O2● redox potential (vs. negative hydrogen electrode potential), but are more close to H2O2/●OH redox potential. Thus, we assume that the photogenerated electrons form ●OH radicals, the species that induce dye decolourization under visible light irradiation. We believe that better performance of composite materials (BiOCl/BNF, BiOCl/BTF) is due to the formation of heterojunction, which facilitates the electron transfer between semiconductors, and O2 vacancy states formation in the BiOCl material.
Ključne besede: nanoparticles, pyrochlore structure, photocatalysis, visible light
Objavljeno: 26.06.2015; Ogledov: 1977; Prenosov: 58
.pdf Polno besedilo (7,29 MB)

60.
Simulation of hot shape rolling of steel by a meshless method
Umut Hanoglu, 2015, doktorska disertacija

Objavljeno: 28.05.2015; Ogledov: 1074; Prenosov: 33
.pdf Polno besedilo (8,16 MB)

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