Dosežki študijskega programa Ekotehnologije
Achievements of the Ecotechnology study program
Barbara Bertoncelj
Vpliv deleža in porazdelitve steklenih vlaken na funkcijske lastnosti kompozitov na osnovi polimerne matrice
Influence of fiber weight content and fiber distribution on functional properties of glass-fiber reinforced composites
Mentor in somentor / Supervisor and Co-Supervisor: Barbara Malič, Janez Rihtaršič
Barbara Bertoncelj je raziskovala povezavo med mikrostrukturo in funkcijskimi lastnostmi kompozitov na osnovi polimerne matrice s steklenimi vlakni (angl: bulk molding compounds, BMC), ki jih uporabljajo za masovno izdelavo različnih izdelkov, predvsem v elektro in avtomobilski industriji ter beli tehniki. Uporabila je vrsto metod kvantitativne mikrostrukturne in stereološke analize za opis mikrostruktur kompozitov, in na osnovi primerjave z modeliranimi mikrostrukturami z naključno porazdelitvijo vlaken določila stopnjo urejenosti mikrostruktur, torej, pri katerem deležu vlaken je njihova porazdelitev najbolj enakomerna. Na osnovi meritev trdnosti, viskoelastičnih in toplotnih lastnosti kompozitov v odvisnosti od deleža vlaken je ugotovila, da je optimalna sestava BMC materiala za določeno uporabo kompromis med zadostno stopnjo urejenosti mikrostrukture in primernimi mehanskimi in toplotnimi lastnostmi.
Barbara Bertoncelj studied the relationship between the microstructure and functional properties of short fiber reinforced polymer-matrix composites (bulk molding compounds, BMC), predominantly used for the mass production of complex-shaped components in electro, automotive and appliance industry. She implemented a range of methods of quantitative microstructural and stereological analysis for the description of the composites. By comparing experimental and modeled microstructures with randomly distributed glass fibers she established the fiber fraction which results in the most uniform distribution of fibers in the polymer matrix. Based on the measurements of flexural strength, viscoelastic and thermal properties of the composites depending on the glass-fiber fraction she concluded that the optimal BMC material composition for a certain application is a compromise between the high level of microstructural uniformity and suitable mechanical and thermal properties.
Zveza med mikrostrukturnimi kazalniki in fizikalnimi lastnostmi kompozitov na osnovi polimerne matrice s steklenimi vlakni v odvisnosti od deleža vlaken (EGF). Mikrostrukturni kazalniki: parameter homogenosti, HPA, radialna porazdelitvena funkcija, RDF, parameter podaljšanja, EP.
Relation between the microstructural descriptors and physical properties of the glass-fiber reinforced polymer-matrix composite as a function of the E-glass fiber (EGF) content. Microstructral descriptors: homogeneity parameter, HPA, radial distribution function, RDF, elongation parameter, EP.
Helena Fajfar
Analiza steklenih, kovinskih in mineralnih predmetov s protonskim žarkom v zraku na področju kulturne dediščine
Analysis of glass, metal and mineral samples of cultural heritage objects with proton beam in the air
Mentor in somentor / Supervisor and Co-Supervisor: Žiga Šmit
Helena Fajfar je v disertaciji študirala sestavo steklenih posod s preloma 19. in 20. stoletja. Uporabila je nedestruktivni metodi protonsko vzbujenih rentgenskih žarkov (PIXE) in žarkov gama (PIGE). Raziskava je zajela dve vrsti stekla: rumeno-zeleno steklo obarvano z uranovimi solmi in rdeče obarvano steklo. Po sestavi je pri obeh vrstah stekla ugotovila tri proizvajalce, dva na območju današnje Slovenije, tretja vrsta stekla pa je predstavljala uvoženo steklo, verjetno čeških steklarjev. Rdeče steklo je bilo izdelano v obliki sendviča iz belega stekla, na katerem je bila tanka rdeča plast. Nosilec rdeče barve v njej so bili koloidno razpršeni bakrovi ioni.
In her thesis, Helena Fajfar studied the composition of vessel glass from the turn of the 19th/20th centuries, using the non-destructive methods of proton induced X-rays (PIXE) and gamma rays (PIGE). Two type of glass were under study: green/yellow glass colored by uranium salts, and red-colored glass. According to the glassmaking recipes, three producers were recognized for both type of glass. Two of them were identified on the territory of the present Slovenia, while the third type of glass was imported, probably from Bohemia. The red glass was made as a sandwich of white glass and thin red layer, whose coloring agent were colloidally dispersed copper ions.
Karakterizacija uranovih stekel po sestavi, z upoštevanjem oksidov Na, Mg, Al, Si, P, K in Ca. Metoda glavnih osi (PCA) je dopolnjena z minimizacijo funkcije STRESS1, pri redukciji podatkov se v dveh dimenzijah ohrani 76,8 % prvotne variacije.
Characterisation of uranium glasses according to their major composition, taking into account the oxides of Na, Mg, Al, Si, P, K and Ca. Principal component analysis (PCA) complemented by minimization of the STRESS1 function was used for data reduction, preserving 76·8% of the original variance in two dimensions.
Jan Gačnik
Metrologija določanja živega srebra v zraku
Metrology of mercury measurements in the air
Mentor in somentor / Supervisor and Co-Supervisor: Milena Horvat, Jože Kotnik
Dr. Jan Gačnik je razvil in apliciral novo kalibracijsko metodo za oksidirano živo srebro v plinasti fazi (HgO, HgCl2, and HgBr2), ki temelji na oksidaciji elementarnega živega srebra s pomočjo hladne plazme. Razvoj metode je omogočila uporaba radioaktivnega sledilca 197Hg, saj se lahko z njim zaradi visoke občutljivosti ter minimalnih interferenc izvajajo eksperimenti pri izredno nizkih koncentracijah, ki jih najdemo tudi v okolju. Razvita metoda predstavlja prvi vir plinastega oksidiranega živega srebra, ki je sledljiv do Mednarodnega sistema enot (SI). Znanstvena objava tega dela je bila izpostavljena na naslovnici revije Analytical Chemistry. Poleg tega so razviti protokoli za delo z radioaktivnim sledilcem 197Hg odprli novo področje raziskav atmosferskega Hg na Institutu Jožef Stefan, iz katerega je bilo od leta 2021 objavljenih 6 znanstvenih prispevkov.
Dr. Jan Gačnik developed and applied a novel calibration method for gaseous oxidized mercury species (HgO, HgCl2, and HgBr2) based on nonthermal plasma-assisted oxidation of gaseous elemental mercury (Hg0). Method development was enabled by the use of 197Hg radiotracer (high sensitivity and lack of interferences), enabling conducting experiments at ambient air Hg concentrations. The developed calibration method was the first System of Units (SI) traceable source of gaseous oxidized mercury and the related publication was featured on the cover page of the journal Analytical Chemistry. Additionally, 197Hg radiotracer protocols and methodologies for first-time radiotracer studies of atmospheric Hg were established, opening a new area of research at the Jožef Stefan Institute, resulting in 6 publications since 2021.
Naslovnica revije Analytical Chemistry: prikaz kalibracijske metode za oksidirane oblike živega srebra v zraku, pri kateri je bila uporabljena hladno plazmo za oksidacijo Hg0 do HgII v prisotnosti reaktivnih plinov.
Cover of the journal Analytical Chemistry: calibration method for gaseous oxidized mercury where cold plasma was used for oxidation of Hg0 to HgII in the presence of reactive gases.
Matej Holc
Učinki obdelave z visoko reaktivno plinsko plazmo na kaljenje in rast česna
Effects of highly reactive gaseous plasma treatment on the germination and growth of garlic
Mentor in somentor / Supervisor and Co-Supervisor: Miran Mozetič, Ita Junkar
Matej Holc je raziskoval vpliv nizkotlačne radiofrekvenčne kisikove plazme na kaljenje in rast slovenskega česna sorte “Ptujski spomladanski”. Uspešno je izboljšal rast in pridelek česna z uporabo okolju prijazne obdelave s plazmo. Z uporabo plazemskih reaktorjev pilotnega in industrijskega merila je analiziral spremembe v fizikalno-kemijskih in bioloških lastnostih neolupljenih in olupljenih strokov česna. Dokazal je, da plazemska obdelava znatno poveča vsebnost kisika na površini, spremeni morfologijo površine in izboljša omočljivost, kar so pokazale analize XPS, ATR-FTIR, SEM in AFM. Te spremembe so vodile do izboljšane rasti kalčkov in korenin v laboratorijskih pogojih ter povečanega pridelka v poljskih poskusih, pri čemer so pozitivni učinki vztrajali tudi v naslednjih generacijah. Rezultati dokazujejo, da lahko plazemska obdelava postane dragocena kmetijsko metoda za spodbujanje kaljenja in povečanje pridelka česna brez dodatnih obdelav, kar podpira trajnostne kmetijske prakse.
Matej Holc investigated the impact of low-pressure, radio frequency oxygen plasma on the germination and growth of the Slovenian garlic cultivar “Ptujski spomladanski”. He managed to enhance garlic growth and yield through an eco-friendly plasma treatment. Using pilot-scale and industrial-scale plasma reactors, he analyzed changes in the physico-chemical and biological properties of unpeeled and peeled garlic cloves. He proved that plasma treatment significantly increased surface oxygen content, modified surface morphology, and improved wettability, as shown by XPS, ATR-FTIR, SEM, and AFM analyses. These changes led to enhanced sprout and root growth in laboratory settings and increased yield in field experiments, with benefits persisting in subsequent generations. The results suggest that plasma treatment can be a valuable agricultural tool for boosting garlic germination and yield without additional treatments, supporting sustainable agricultural practices.
Rast poganjkov olupljenih strokov česna, zabeležena po 140 urah rasti: (a) neobdelan in (b) obdelan s plazmo.
Peeled garlic clove sprout growth recorded after 140 h of growth: (a) untreated and (b) plasma treated.
Metod Kolar
Izboljšanje biokompatibilnosti površine poli(etilen tereftalata) z imobilizacijo heparina
Improving biocompatibility of poly(ethylene terephthalate) surfaces by immobilization of heparin
Mentor in somentor / Supervisor and Co-Supervisor: Miran Mozetič, Alenka Vesel, Karin Stana – Kleinschek
Metod Kolar je v sklopu raziskav za doktorsko disertacijo razvil in patentiral izvirni postopek za vezavo monoplasti proti-trombogenega sredstva heparina na površino polimera, ki se standardno uporablja za izdelavo umetnih žil. Vzorce iz polietilen tereftalata je namestil v pozno porazelektritev nizkotlačne šibkoionizirane amonijakove plazme, ki jo je vzbujal z mikrovalovno razelektritvijo v surfatronskem načinu delovanja. S spretno zastavljenim eksperimentom je uspel izpostaviti polimerno površino radikalom NH2, ki so omogočili vezavo amino skupin na površino polimera. V naslednjem koraku je s kemijsko metodo kovalentno vezal monoplast heparina, ki velja za enega od najbolj protitrombogenih molekul. Zaradi kovalentne vezave je bila monoplast stabilna, tako da je preprečila površinsko aktivacijo trombocitov. Na neobdelani površini polimera pa je že po kratkotrajni inkubaciji s človeško krvjo opazil spremembo morfologije trombocitov in ireverzibilno vezavo krvnih proteinov, kar je znak za začetek nastanka krvnega strdka.
Metod Kolar developed and patented an original method for binding a monolayer of an anti-thrombogenic agent heparin to the surface of a polymer, which is standardly used for the production of artificial veins. He placed polyethylene terephthalate polymer samples in the late afterglow of a low-pressure, weakly ionized ammonia plasma, which he excited with a microwave discharge in the surfatron mode of operation. With a skillfully designed experiment, he managed to expose the polymer surface to NH2 radicals, which enabled the binding of amino groups to the polymer surface. In the next step, he used a chemical method to covalently bind a monolayer of heparin, which is considered one of the most anti-thrombogenic molecules. Due to the covalent binding, the monolayer was stable, preventing surface activation of platelets. On the untreated surface of the polymer, even after a short incubation with human blood, he noticed a change in the morphology of platelets and irreversible binding of blood proteins, which is a sign of the beginning of the formation of a blood clot.
Postopek obdelave umetne žile s plazmo in kovalentna vezava heparina za doseganje protitrombogenih površin.
A procedure for treating an artificial vascular graft with plasma and covalent binding of heparin for obtaining antithrombogenic surfaces.
Ana Kovačič
Ostanki bisfenolov v vodnem okolju: pojavnost in kroženje
Bisphenol residues in the aqueous environment: Occurrence and fate
Mentor in somentor / Supervisor and Co-Supervisor: Ester Heath, Tina Kosjek
V raziskavi smo proučevali privzem 14 spojin, ki vzbujajo zaskrbljenost (ang. Contaminants of Emerging Concern, CEC) in 27 elementov v paradižnike z uporabo LC-MS/MS in ICP-MS. Paradižnike smo gojili hidroponično in v lizimetrih, ter jih namakali s pitno in prečiščeno odpadno vodo. V plodovih paradižnika smo pokazali privzem bisfenola S , 2,4 bisfenola F in naproksena. Prisotnost teh spojin je bila ugotovljena tako v primeru namakanja s pitno kot odpadno vodo, pri čemer je bila najvišja koncentracija ugotovljena za BPS (0,034–0,134 µg kg−1 mokre teže). Prisotne ravni vseh treh spojin so bile statistično pomembnejše pri paradižnikih, pridelanih hidroponično v primerjavi z lizimetri. Elementna sestava je pokazala razlike med paradižniki pridelanimi hidroponično ali v zemlji in paradižniki, namakanimi s prečiščeno odpadno ali pitno vodo. Ocenjeni prehranski vnos onesnaževal pri ugotovljenih koncentracijah predstavlja nizko kronično izpostavljenost, rezultati pa bodo pomembni pri oceni tveganja.
In this study, the uptake of 14 chemicals of emerging concern (CECs) and 27 potentially toxic elements (PTEs) was studied in tomatoes grown in soil-less (hydroponically) and soil (lysimeters) media irrigated with potable and treated wastewater using LC-MS/MS and ICP-MS. Bisphenol S, 2,4 bisphenol F, and naproxen were detected in fruits irrigated with spiked potable water and wastewater under both conditions, with BPS having the highest concentration (0.034-0.134 µg kg-1 f. w.). The levels of all three compounds were statistically more significant in tomatoes grown hydroponically than in soil. Their elemental composition shows differences between tomatoes grown hydroponically or in soil and tomatoes irrigated with wastewater and potable water. Contaminants at determined levels showed low dietary chronic exposure. When the health-based guidance values for the studied CECs are determined, results from this study will be helpful for risk assessors.
Privzem onesnaževal v paradižnikih gojenih s prečiščeno odpadno vodo.
Contaminant uptake in wastewater irrigated tomatoes.
Dane Lojen
Funkcionalizacija fluoriranih polimerov z nizkotlačnimi plazmami
Low-pressure plasma functionalisation of fluoropolymers
Mentor in somentor / Supervisor and Co-Supervisor: Rok Zaplotnik, Alenka Vesel
Dane Lojen je raziskal metode za doseganje velike gostote radikalov dvoatomnih plinov v velikim plazemskih posodah. Izdelal je sistem z več plazmami v H-načinu sklopitve, ki jih je vzbujal z vzporedno vezanim radiofrekvenčnim generatorjem. Plinsko plazmo je uporabil za aktivacijo površine fluoriranih polimerov. Uporabil je dvostopenjsko obdelavo. V prvem koraku je polimerno površino obdelal z vodikovo plazmo z veliko gostoto absorbirane moči, ki je močan vir vakuumske ultravijolične svetlobe in atomarnega vodika. Obdelava z vodikovo plazmo je omogočila zamenjavo fluora z vodikom v zelo tanki površinski plasti. V naslednjem koraku je tako spremenjeno površino obdelal z majhno dozo atomarnega kisika in dosegel super-hidrofilnost teflona, ki sicer velja za enega od najbolj hidrofobnih polimerov. Podrobno je raziskal kinetiko funkcionalizacije s polarnimi skupinami in določil območje doz atomarnega kisika, ki omogoči super-hidrofilnost tega polimera.
Dane Lojen investigated methods for achieving a high density of radicals in large plasma vessels. He built a system with several plasmas in H-coupling mode, parallelly connected to a radio frequency generator. He used gas plasma to activate the surface of fluorinated polymers using a two-stage processing. In the first step, he treated the polymer surface with a high-power density hydrogen plasma, which is an extensive source of vacuum ultraviolet radiation and atomic hydrogen. Treatment with hydrogen plasma caused the substitution of fluorine with hydrogen in a very thin surface layer. In the next step, he treated such a modified surface with a small dose of atomic oxygen. He achieved the super-hydrophilicity of fluorine-containing polymers such as polytetrafluoroethylene, which are otherwise considered one of the most hydrophobic polymers. He investigated in detail the kinetics of functionalization with polar functional groups and determined the range of atomic oxygen doses that enable the super-hydrophilicity of this polymer.
Fotografija več plazemskih virov nameščenih v kovinsko vakuumsko posodo.
A photo of several plasma sources embedded into a metallic vacuum chamber.
Katarina Marković
Speciacija rutenijevih spojin za zdravljenje raka in bakra kot možnega biomarkerja pri diagnostiki raka v humanem serumu
Speciation of ruthenium-based candidate drugs for cancer treatment and copper as a potential biomarker for cancer diagnosis in human serum
Mentor in somentor / Supervisor and Co-Supervisor: Radmila Milačič
Ceruloplazmin (Cp) je glavni protein, ki prenaša baker (Cu) v človeški plazmi. Zaradi pomembnih fizioloških funkcij Cu in njegove vloge pri različnih boleznih je treba kvantificirati koncentracijo Cu, ki je v človeškem krvnem serumu vezan na Cp in izmenljivo obliko Cu. Za ločbo Cu, ki je v serumu vezan na nizkomolekularne zvrsti (LMM), Cp in albumin (HSA) smo kot prvi uporabili združeno tekočinsko kromatografijo (CLC) na monolitnih diskih s konvektivnim prenosom snovi (CIM). Dva imunoafinitetna CIMmic diska za vezavo albumina (α-HSA) in en CIMmic šibko anionsko izmenjalni disk (DEAE) smo združili v eno ohišje CLC kolone. Med kromatografsko ločbo, kjer smo uporabili gradientno elucijo z 1 M NH4Cl (pH 7,4), se je HSA zadržal na disku α-HSA ter omogočil ločitev Cu, ki je vezan na Cp od tistega, ki je vezan na LMM zvrsti, na DEAE disku. Nadaljevanje elucije z 0,5 M ocetno kislino je spralo HSA z diska α-HSA. Ločene Cu zvrsti smo kvantificirali s po-kolonsko ID-ICP-MS. Opisani analizni postopek smo uspešno uporabili pri določanju Cu-Cp, Cu-HSA in Cu-LMM v človeškem serumu zdravih posameznikov, bolnikov s presajeno ledvico in bolnikov z rakom.
Ceruloplasmin (Cp) is the major copper-carrying (Cu) protein in human plasma. Due to important physiological functions of Cu and its role in various diseases, there is a need to quantify the concentration bound to Cp and the exchangeable form of Cu in human serum. Conjoint liquid chromatography (CLC) on short-bed convective interaction media (CIM) monolithic disks was used for the first time in speciation of Cu in human serum. Two immunoaffinity CIMmic albumin depletion (α-HSA) disks and one CIMmic weak anion-exchange (DEAE) disk were assembled in a single housing, forming a CLC monolithic column. The instrumental set-up enabled retention of HSA on the α-HSA disk and subsequent separation of the LMM-Cu from the Cu bound to the Cp on the DEAE disk using gradient elution with 1 M NH4Cl (pH 7.4). Further elution with 0.5 M acetic acid rinsed the HSA from the α-HSA disk. The separated Cu species were quantified by post-column ID-ICP-MS. The technique was successfully applied in the determination of Cu-Cp, Cu-HSA and Cu-LMM species in the human serum of healthy individuals, kidney transplant patients and cancer patients.
Ločba Cu zvrsti v humanem serumu z uporabo CLC monolitne kolone in kvantifikacijo ločenih Cu zvrsti s po-kolonsko ID-ICP-MS.
Separation of Cu species in human serum using a monolithic CLC column and quantification of separated Cu species by post-column ID-ICP-MS.
Stefan Marković
Kvantitativno slikanje cisplatina v onkoloških vzorcih z lasersko ablacijo z masno spektrometrijo z induktivno sklopljeno plazmo
Quantitative imaging of cisplatin in tumour samples by laser ablation inductively coupled plasma mass spectrometry
Mentor in somentor / Supervisor and Co-Supervisor: Janez Ščančar, Janja Vidmar
Z metodo laserske ablacije sklopljene z masno spektrometrijo z induktivno sklopljeno plazmo (LA-ICP-MS) smo kvantitativno določili prostorsko porazdelitve platine (Pt) v tumorskih sferoidih, ki smo jih tretirali s cisplatinom (CDDP) ali cisplatinom, ki je bil označen s fluorofornim barvilom Texas Red (TR-CDDP). Vsebnost Pt v posameznih slikovnih točkah, z dimenzijo 2,0 x 2,5 mm, smo kvantificirali z uporabo želatinskih standardov in tehnike izotopskega redčenja (ID). Kvantitativna vizualizacija Pt z LA-ICP-MS nam je omogočila primerjavo prostorske porazdelitve Pt v tumorskih sferoidih, ki smo jih tretirali s CDDP in TR-CDDP. Eksperimentalni rezultati so pokazali, da se farmakokinetika CDDP razlikuje od TR-CDDP. Porazdelitev TR-CDDP v tumorskih sferoidih, ki smo jo analizirali, najprej s konfokalno fluorescenčno mikroskopijo in nato z uporabo LA-ICP-MS, je pokazala, da se intenzivnost signala fluorescence TR-CDDP dobro ujema s koncentracijami Pt, ki smo jih določili z LA-ICP-MS. Z uporabo ID-LA-ICP-MS smo pripravili tudi kvantitativne 3D slike sferoidov, ki smo jih tretirali s CDDP ali TR-CDDP.
Laser ablation – inductively coupled plasma mass spectrometry (LA-ICP-MS) instrumental set-up was applied for the quantitative determination of the spatial distribution of platinum (Pt) in tumour spheroids treated with cisplatin (CDDP) or cisplatin marked with the fluorophore dye Texas Red (TR-CDDP). For the quantification of Pt content in individual pixels with dimension of 2.0 x 2.5 mm, matrix-matched gelatine standards and the isotope dilution (ID) technique were used. Quantitative imaging of Pt by LA-ICP-MS enables us to compare the spatial distribution of the Pt in tumour spheroids treated with CDDP and TR-CDDP. The pharmacokinetics of CDDP have been shown to differ from that of TR-CDDP. The distribution of TR-CDDP in tumour spheroids analysed first by confocal fluorescence microscopy and then using LA-ICP-MS shows that the intensity of the TR-CDDP fluorescence matched well with the Pt concentrations determined using LA-ICP-MS. 3D quantitative images of spheroids treated with CDDP or TR-CDDP using ID-LA-ICP-MS were also created.
3D slike porazdelitve Pt iz dveh sferoidov HT29, pridobljene z ID-LA-ICP-MS po 1-urni inkubaciji z A) 100 µM CDDP in B) 100 µM TR-CDDP.
3D images of Pt distribution from two HT29 spheroids obtained by ID-LA-ICP-MS after incubation for 1 h with A) 100 µM CDDP and B) 100 µM TR-CDDP.
Matjaž Novak
Genotoksični potencial ostankov citostatikov: pomen za vodno okolje in ljudi
Genotoxic potency of cytostatic drug residues: the relevance for aquatic environment and humans
Mentor in somentor / Supervisor and Co-Supervisor: Metka Filipič, Bojana Žegura
Dr. Matjaž Novak je v doktorski disertaciji dokazal, da številni citostatiki, ki se pogosto uporabljajo za zdravljenje rakavih obolenj, povzročajo genotoksične učinke v netarčnih jetrnih celicah rib cebric in človeka ter da so nekateri presnovni in/ali transformacijski produkti bolj toksični in nevarni kot so starševske spojine. Poleg tega mešanice citostatikov povzročajo genotoksične učinke pri nizkih okoljsko pomembnih koncentracijah, pri katerih pa posamezni citostatiki niso aktivni. V dvogeneracijski študiji toksičnosti, kjer smo ribe cebrice preko dveh generacij izpostavili okoljsko pomembnim koncentracijam 5-Fluorouracila (10 ng/L), smo opazili genotoksične učinke in deregulacijo izražanja onkogenov in genov, ki se odzovejo na poškodbe DNA, medtem ko na klasične toksikološke parametre niso vplivali. Doktorsko delo je pokazalo, da nekateri citostatiki, ki se pogosto uporabljajo v kliniki, predstavljajo tveganje za okolje in ljudi že v zelo nizkih koncentracijah.
Dr. Matjaž Novak demonstrated in his doctoral dissertation that several of the most commonly used cytostatic drugs cause genotoxic effects in non-target hepatic zebrafish and human cells, and that certain metabolites and/or transformation products are even more toxic and dangerous than the parent compounds. In addition, mixtures of cytostatics induce genotoxic effects at low environmentally relevant concentrations at which individual compounds are inactive. In a two-generation toxicity study in zebrafish, genotoxic effects and deregulation of several DNA damage-responsive genes and oncogenes were observed after chronic exposure to environmentally relevant concentrations of 5-fluorouracil (10 ng/L), while classical toxicological endpoints were not affected. Overall, the work showed that certain commonly used cytostatics pose a risk to the environment and humans even at very low concentrations.
Citostatiki povzročajo DNA in genomske poškodbe ter spremembe v izražanju genov pri izpostavljenih ribjih in človeških celicah.
Cytostatics induce DNA damage, genomic instability and changes in gene expression in treated fish and human cells.
Rok Novak
Ocena individualne izpostavljenosti onesnažilom iz zraka z uporabo osebnega monitoringa
Assessment of individual-level exposure to air pollutants using personal monitoring
Mentor in somentor / Supervisor and Co-Supervisor: Kocman David
Članek z naslovom »Simulating the impact of particulate matter exposure on health-related behaviour: a comparative study of stochastic modelling and personal monitoring data« objavljen v reviji Health & place (IF 4.8) obravnava razvoj stohastičnega, t. i. Agent-Based modela za oceno izpostavljenosti posameznika onesnažilom iz zraka ter možnosti le-tega za testiranje različnih okoljskih scenarijev. Tovrstni virtualni modelni pristopi, v kombinaciji s podatki, zbranimi v participativni vzorčevalni kampanji za potrebe validacije in kalibracije, so se izkazali za zelo učinkovit način za izdelavo orodja za prilagoejnega potrebam odločevalcev in oblikovalcev okoljskih politik.
The article “Simulating the impact of particulate matter exposure on health-related behaviour: a comparative study of stochastic modelling and personal monitoring data” published in Health & place (IF 4.8) discusses the development of a stochastic ABM (Agent-Based Model) for estimating individual exposure to air pollutants and its potential for testing different environmental scenarios. Such virtual modelling approaches, combined with data collected in a participatory sampling campaign for validation and calibration purposes, have proven to be a very effective way to produce a tool tailored to the needs of decision-makers and environmental policy-makers.
Prostorski prikaz agentnega modela izpostavljenosti in odmerka PM2.5 z začetno nastavitvijo. Prikazano pri 368. iteraciji (ure) v grafičnem vmesniku okolja NetLogo.
Visualization of the spatial representation of the PM2.5 exposure and dose agent-based model with the initial setting, at 368 h in the NetLogo graphical user interface.
Ana Oberlintner
Površinske modifikacije celuloznih nanomaterialov: mehanizmi, kinetika in njihove aplikacije
Surface modifications of cellulose nanomaterials: mechanisms, kinetics and their applications
Mentor in somentor / Supervisor and Co-Supervisor: Uroš Novak, Blaž Likozar
Celulozni nanomateriali (CN) imajo zaradi sposobnosti tvorbe filmov s primernimi mehanskimi lastnostmi, obnovljivosti, biokompatibilnosti, netoksičnosti in biorazgradljivosti visok potencial za uporabo v pakirni industriji. Trenutno omejitev za takšne aplikacije pa predstavlja njihova hidrofilnost, zato je v okviru doktorske dizertacije Ana Oberlintner raziskovala mehanizme in kinetiko hidrofobnih modifikacij celuloznih nanomaterialov, ki so ključnega pomena za njihovo širšo uporabo. Najprej je proučevala njihovo esterifikacijo, s poudarkom na kinetiki in mehanizmu reakcije, razvila je tudi mikrokinetični model. Modificirane CN je vkomponirala v biokompozite ter ovrednotila njihovo primernost za embalažne materiale. Za celostno ovrednotenje trajnostnega vidika takšne embalaže je izvedla tudi študijo njihove biorazgradljivosti. Drugi del je osredotočen na uporabo plazme, saj omogoča izjemno hitro (20 s ali manj) stabilno hidrofobizacijo in ne zahteva dodatnih separacijskih procesov.
Cellulose nanomaterials (CN) exhibit high potential for use as packaging due to their ability to form films with suitable mechanical properties, renewability, biocompatibility, non-toxicity and biodegradability. To overcome their current their limitation for such applications, hydrophilicity, Ana Oberlintner researched the mechanisms and kinetics of hydrophobic modifications, which are crucial for their wider use. First, she studied their esterification, with an emphasis on the kinetics and mechanism of the reaction, and she also developed a microkinetic model. She incorporated the modified CN into biocomposites and evaluated their suitability for packaging materials. In order to comprehensively evaluate the sustainability aspect of such packaging, she also conducted a study of their biodegradability. The second part is focused on the use of plasma, as it enables extremely fast (20 s or less) stable hydrophobization and does not require additional separation processes.
Večstopenjska študija esterifikacije celuloznih nanokristalov in celuloznih nanofibril z eksperimentalnimi podatki, ab initio izračuni in mikrokinetiko kemijskih reakcij.
Multiscale study of cellulose nanocrystals and cellulose nanofibrils esterification featuring experimental data, ab initio calculations and chemical reaction microkinetics.
Primož Oprčkal
Napredni pristopi za trajnostno remediacijo onesnažene vode in zemljin
Innovative approaches for sustainable remediation of contaminated waters and soils
Mentor in somentor / Supervisor and Co-Supervisor: Janez Ščančar, Ana Mladenovič
V sodelovanju z raziskovalci Instituta Jožef Stefan, smo kritično ocenili uporabnost različnih nanodelcev ničvalentnega železa (nZVI), za nanoremediacijo odpadne vode iz iztoka male biološke čistilne naprave. V ta namen smo preučevali v laboratoriju sintetizirane nZVI in komercialno dostopne nanodelce Nanofer STAR in Nanofer25 slurry. Rezultati so pokazali, da so v laboratoriju sintetizirani nZVI, ki so bili najbolj reaktivni, najbolj učinkovito odstranili kovine in uničili patogene bakterije (Coliform bacteria, Escherichia coli, Intestinal Enterococci and Clostridium perfringens). Kljub temu pa je njihova uporaba omejena, ker se med remediacijo, v vodo, ki jo čistimo sprosti element bor, ki se uporablja pri sintezi nZVI. Vse vrste preučevanih nZVI so v določenem deležu reducirale nitrate in nitrite v amonijev kation. Dodatno pa se je amonijev kation tvoril tudi iz organskega dušika prisotnega v odpadni vodi iz iztoka male biološke čistilne naprave. Zato je po remediaciji potrebno slediti njegovi koncentraciji, da ne bi presegli zakonsko predpisanih mejnih vrednosti. Kot najbolj učinkovit, pri odstranjevanju kovin in kot najbolj učinkovito sredstvo za dezinfekcijo, se je izkazal Nanofer25 slurry.
In collaboration with researchers from the Slovenian National Building and Civil Engineering Institute and the Jožef Stefan Institute, we critically evaluated the applicability of various nanoparticles of zero-valent iron (nZVI) for the nanoremediation of wastewater effluent from a small biological treatment plant. For this purpose, we studied nZVI synthesized in the laboratory and commercially available nanoparticles Nanofer STAR and Nanofer25 slurry. The results showed that nZVIs synthesized in the laboratory, which were the most reactive, most effectively removed metals and inactivated pathogenic bacteria (Coliform bacteria, Escherichia coli, Intestinal Enterococci and Clostridium perfringens). Nevertheless, their use is limited because the boron used in the synthesis of nZVI is released during remediation into the water being treated. To a certain extent, all of the investigated types of nZVI reduced nitrates and nitrites to ammonium cation. In addition, the ammonium cation was also formed from organic nitrogen present in the water from the effluent of a small biological treatment plant. Therefore, after remediation, it is necessary to monitor its concentration in order not to exceed the legally prescribed limit values. Nanofer25 slurry has proven to be the most effective in removing metals and the most efficient disinfectant of pathogenic bacteria.
Procesi, ki vplivajo na pretvorbo organskih in anorganskih kemijskih zvrsti dušika po čiščenju odpadne vode iz male biološke čistilne naprave z različnimi delci nZVI.
Processes influencing the transformation of organic and inorganic chemical species of nitrogen after the treatment of wastewater from a small biological wastewater treatment plant with different nZVI particles.
Domen Paul
Heterogena rekombinacija nevtralnih kisikovih atomov na površinah oksidiranih materialov
Heterogeneous recombination of neutral oxygen atoms on the surfaces of oxidized materials
Mentor in somentor / Supervisor and Co-Supervisor: Miran Mozetič, Rok Zaplotnik
Domen Paul je podrobno raziskal kinetiko heterogene površinske rekombinacije atomarnega kisika na površinah katalitičnih materialov. Uspel je izpopolniti metodo za določanje absolutne vrednosti gostote atomarnega kisika v porazelektritveni posodi. Različne gostote je dosegel s spreminjanjem pretoka plina skozi plazmo, ki jo je vzbujal s površinsko mikrovalovno razelektritvijo, spreminjanjem izhodne moči mikrovalovnega vira in položajem titanovega rekombinatorja vzdolž kremenove cevi, ki je povezovala razelektritveno in porazelektritveno posodo. Tovrstna eksperimentalna postavitev je omogočila meritve rekombinacijskih koeficientov pri različnih tlakih in temperaturah katalitičnega materiala. Tlačno odvisnost je pojasnil s sinergističnim učinkom adsorbiranih molekul in atomov, temperaturno pa s površinsko difuzijo adsorbiranih atomov zaradi kvantnega značaja razpoložljivih mest za površinsko adsorpcijo atomov kisika na oksidirani površini niklja in kobalta.
Domen Paul has investigated in detail the kinetics of heterogeneous recombination of atomic oxygen on the surfaces of catalytic materials. He succeeded in perfecting the method for determining the absolute value of the density of atomic oxygen in a discharge vessel. He achieved different atom densities by varying the flow of gas through the plasma, which he excited with a surface microwave discharge, by varying the output power of the microwave source, and by the position of the titanium recombinator along the quartz tube that connected the discharge and afterglow vessels. The experimental setup enabled measurements of recombination coefficients at different pressures and temperatures of the catalytic material. He explained the pressure dependence with the synergistic effect of adsorbed molecules and atoms and the temperature dependence with the surface diffusion of adsorbed atoms due to the quantum character of the available sites for the surface adsorption of oxygen atoms on the oxidized surface of nickel and cobalt.
Karakterizacija uranovih stekel po sestavi, z upoštevanjem oksidov Na, Mg, Al, Si, P, K in Ca. Metoda glavnih osi (PCA) je dopolnjena z minimizacijo funkcije STRESS1, pri redukciji podatkov se v dveh dimenzijah ohrani 76,8 % prvotne variacije.
Characterisation of uranium glasses according to their major composition, taking into account the oxides of Na, Mg, Al, Si, P, K and Ca. Principal component analysis (PCA) complemented by minimization of the STRESS1 function was used for data reduction, preserving 76·8% of the original variance in two dimensions.
Matic Resnik
Plazemska modifikacija polipropilenskih tubic za uporabo v biomedicini
Plasma-induced modifications of polypropylene tubes for biomedical applications
Mentor in somentor / Supervisor and Co-Supervisor: Miran Mozetič, Ita Junkar
Matic Resnik je preučeval učinke obdelave standardnih polipropilenskih mikrocentrifugirnih epruvet s hladno plazmo pri atmosferskem tlaku za uporabo v biomedicinskih aplikacijah. Osredotočil se je na optimizacijo parametrov plazemske obdelave, izdelavo avtomatske naprave za plazemsko obdelavo za dosledno modifikacijo notranjih površin epruvet ter preučevanje posledičnega mikrobiološkega odziva mikroveziklov in proteinov na te površine. Ugotovitve so pokazale, da je plazemska obdelava znatno izboljšala lastnosti površin epruvet, kar je vodilo do izboljšane izolacije mikroveziklov in adsorpcije proteinov ter s tem pokazalo potencial za učinkovitejše biomedicinske aplikacije z uporabo plazemsko obdelanih polipropilenskih epruvet. Študija poudarja kompleksnost interakcij med plazmo in polimerom ter pomen natančnega nadzora nad pogoji plazemske obdelave za dosego želenih sprememb na površini, kar prispeva k napredku na področju biomedicinskega inženiringa in znanosti o materialih.
Matic Resnik investigated the effects of cold atmospheric pressure plasma treatment on standard polypropylene microcentrifuge tubes used in biomedical applications. He focused his research on optimizing plasma treatment parameters, constructing an automatic plasma treatment device for consistent modification of the tubes’ inner surfaces, and studying the subsequent microbiological response of microvesicles and proteins to these surfaces. The findings revealed that the plasma treatment significantly enhanced the tubes’ surface properties, leading to improved microvesicle isolation and protein adsorption, demonstrating the potential for more effective biomedical applications using plasma-treated polypropylene tubes. The study highlights the complexities of plasma-polymer interactions and the importance of precise control over plasma treatment conditions to achieve desired surface modifications.
Plazemska obdelava mikrocentrifugalnih epruvet z atmosferskim tlakom za biomedicinsko uporabo pri izolaciji mikroveziklov.
Atmospheric-pressure plasma treatment of microcentrifuge tubes for biomedical application in microvesicle isolation.
Leja Rovan
Metoda za določanje uranovih izotopskih razmerij in njena uporaba kot novo geokemijsko sledilo
Method for the determination of uranium isotope ratios and its application as novel geochemical tracer
Mentor in somentor / Supervisor and Co-Supervisor: Marko Štrok
Leja Rovan je razvila metodo za določanje razmerij izotopov urana v vzorcih vode in kamnin z mutlikolektorsko masno spektrometrijo na induktivno sklopljeno plazmo (MC-ICP-MS) za preučevanje geokemičnih procesov v kraškem okolju. To je bilo zelo zahtevno zaradi zelo nizkih koncentracij urana v takih okoljih z variacijami izotopskega razmerja v velikostnem redu od nekaj promilov do nekaj odstotkov. Razvita metoda vključuje predkoncentracijo vzorcev vode s Ca3(PO4)2, odstranjevanje nečistoč in interferenc z ekstrakcijsko kromatografijo UTEVA ter meritve na MC-ICP-MS. Uporabljena je bila za proučevanje geokemičnih procesov v kraških porečjih reke Ljubljanice v Sloveniji in reke Krke na Hrvaškem. Rezultati so pokazali, da razmerja aktivnosti 234U/238U zagotavljajo uporabne informacije o časih pretoka vode, stopnjah preperevanja, topnosti in prepustnosti kamnin, kot tudi za kvantifikacijo ponorov CO2 v kraških porečjih.
Leja Rovan developed method for the determination of uranium isotope ratios in water and rock samples with multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS) to study geochemical processes in karstic environment. This was very challenging due to the very low concentrations of uranium in such environments with isotope ratio variations in the order of few permilles to few percent. The developed method involves pre-concentration of water samples with Ca3(PO4)2, removal of impurities and interferences with UTEVA extraction chromatography and measurements on MC-ICP-MS. It has been applied to study geochemical processes in the karstic river catchments of Ljubljanica River in Slovenia and Krka River in Croatia. The results showed that 234U/238U activity ratios provide useful information on water transit times, weathering rates, solubility and permeability of rocks, as well as for the quantification of CO2 sinks in carstic watersheds.
Slika MC-ICP-MS inštrumenta za določanje razmerij izotopov urana za preučevanje geokemičnih procesov v kraškem okolju.
Picture of the MC-ICP-MS instrument used for the determination of uranium isotope ratios to study geochemical processes in karstic environment.
Agneta Annika Runkel
Tarčna analiza organskih kontaminantov, ocena izpostavljenosti, in ranljivosti populacij za nevarne spojine
Targeted analysis of organic contaminants, exposure assessment, and vulnerability of populations to hazardous compounds
Mentor in somentor / Supervisor and Co-Supervisor: Milena Horvat, Tina Kosjek
Obstojna organska onesnaževala (POP) zaradi svoje obstojnosti in strupenosti predstavljajo skrb za okolje in zdravje ljudi. Zato smo proučevali izpostavljenost POP-om (PCDD/F, PCB, PBDE, organoklorni pesticidi (OC)) 1084 moških in žensk v Sloveniji. Večino POP-ov je bilo mogoče določiti v materinem mleku v nizkih koncentracijah (PCDD/F in PCB: 3,04 pg/gTEQ, ΣPBDE: 1076 ng/g), medtem ko smo od OC določili le metabolite HCB in DDT (5 – 60 ng/g). V plazmi moških so bile frekvence in ravni kontaminantov nižje (PCDD/F in PCB: 0,09 pg/gTEQ, ΣPBDE: 920 pg/g, p,p’-DDE 0,25 ng/g). Ravni obstojnih organskih onesnaževal so bile višje v onesnaženih, industrijskih in mestnih območjih, poleg starosti, cest in starejših hiš pa je bilo uživanje alkohola in živalskih proizvodov povezano z večjo izpostavljenostjo. Na splošno je izpostavljenost Slovencev POP-om nizka, kar potrjujejo okoljske študije, ki so ugotovile nižje koncentracije POP-ov južno od Alp zaradi učinka alpske pregrade.
Persistent organic pollutants (POPs) represent a concern for the environment and human health due to their persistence and toxicity. Therefore, we studied the exposure to POPs (PCDD/Fs, PCBs, PBDEs, organochlorine pesticides (OCs)) and its sources of 1084 men and women in Slovenia. Most POPs could be determined in maternal milk at low concentrations (PCDD/Fs and PCBs: 3.04 pg/gTEQ, ΣPBDE: 1076 ng/g fat), while of OCs, only HCB and DDT metabolites were determined (5 – 60 ng/g fat). In men’s plasma, the detection frequencies and levels were lower (PCDD/Fs and PCBs: 0.09 pg/gTEQ, ΣPBDE: 920 pg/g, p,p’-DDE 0.25 ng/g). POPs levels were higher in contaminated, industrial, and urban sites and beside age, roads, and older houses, the consumption of alcohol and animal products was associated with higher exposures. Overall, exposure of Slovenians to POPs is low, which is supported by environmental studies that found lower POP concentrations south of the Alps due to the Alpine barrier effect.
Alpe predstavljajo fizično oviro za zračne mase, ki prenašajo kontaminante, kar imenujemo učinek alpske pregrade. Zato so ravni POP-ov v Sloveniji nizke. Stopnje izpostavljenosti pri moških in ženskah so bile višje v onesnaženih, industrijskih in mestnih območjih ter povezane predvsem z uživanjem alkohola in živalskih proizvodov.
The Alps represent a physical barrier to pollutant-carrying air masses, which is known as the Alpine barrier effect. Therefore, the levels of POPs in Slovenia are low. Exposure levels in men and women were higher in contaminated, industrial, and urban sites and primarily associated with the consumption of alcohol and animal products.
Janja Snoj Tratnik
Izpostavljenost prebivalcev Slovenije živemu srebru in povezava z nevropsihološkim razvojem otrok
Exposure to mercury in Slovenia and neurodevelopment of children
Mentor in somentor / Supervisor and Co-Supervisor: Milena Horvat, David Neubauer
V študiji smo raziskali povezavo med prenatalno izpostavljenostjo živemu srebru (Hg) in nevrološkim razvojem otrok, pri čemer smo upoštevali genetski polimorfizem apolipoproteina E (Apoe) in drugih dejavnikov, ki lahko vplivajo na razvoj (prehrana, socio-demografske karakteristike, sočasna izpostavljenost svincu). Koncentracija Hg v popkovni krvi je bila negativno povezana s kognitivnim razvojem ocenjenim z Bayley lestvico pri starosti 18 mesecev, ampak samo pri nosilcih alela Apoe ε4. Opazili smo tudi negativno povezavo med izpostavljenostjo Hg in gibalnim razvojem (fina motorika), ki pa je bila neodvisna od genotipa. Alel povečane občutljivosti ε4 je bil prisoten pri 17 % študijske populacije, pri kateri smo ugotovili normalen razvoj. Pri teh otrocih bi podvojitev izpostavljenosti Hg v prenatalnem obdobju pomenila za 5,4 % slabšo kognitivno oceno. Čeprav obseg tega učinka na individualni ravni ni kritičen, pa ima lahko pomemben vpliv na ravni celotne populacije.
The study evaluated association between prenatal exposure to mercury (Hg) and neurodevelopment of the child, considering genetic polymorphism of apolipoprotein E (Apoe) and other relevant confounders (diet, socio-demographic characteristics, co-exposure to lead). The concentration of total Hg in cord blood was negatively associated with the cognitive performance of children at 18 months of age assessed by Bayley Scales of Infant and Toddler Development, but only in children carrying at least one Apoe ε4 allele. The decrease in fine motor score was also observed with increasing Hg exposure, which was independent of the Apoe genotype. The susceptible allele ε4 is present in 17 % of the study population. In these children, mostly having normal neurodevelopmental outcome, doubling of Hg exposure resulted in 5.4 % lower cognitive performance. Although the extent of this impact is not critical on an individual level, it can have a significant societal impact.
Povezava med prenatalno izpostavljenostjo celokupnemu živemu srebur (THg) in kognitivim razvojem otrok pri 18 mesecih starosti: statistično pomembno povezavo smo opazili za nosilce Apoe ε4 alela. V modelu smo upoštevali materino starost in stopnjo izobrazbe, otrokov spol, porodno težo, kajenje med nosečnostjo ter koncentracijo selena in svinca v popkovni krvi.
Association between prenatal exposure to total mercury (THg) and cognitive performance at 18 months of age: statistically significant association was observed for carriers of Apoe ε4 allele. The model was adjusted for mother’s age and educational level, child’s sex, birthweight, smoking during pregnancy, selenium and lead concentration in cord blood.
Anja Stajnko
Humani geni in genski polimorfizmi in njihovo izražanje v povezavi z elementi v sledovih
Human genes, gene polymorphisms, and their expression in relation to trace elements
Mentor in somentor / Supervisor and Co-Supervisor: Ingrid Falnoga, Milena Horvat
Genetska dovzetnost pri izpostavljenosti anorganskemu arzenu (iAs) je bila večinoma raziskana le pri populacijah z visoko izpostavljenostjo. Zato smo v naši študiji, na podlagi 15 polimorfizmov posameznega nukleotida (SNP) v 7 genih, ocenili vpliv genetske predispozicije na presnovo iAs pri slovensko-hrvaških nosečnicah in nenosečih ženskah ter otrocih, z nizko izpostavljenostjo iAs. Poročali smo o pomembni vlogi specifičnega AS3MT SNP haplotipa pri učinkovitejši metilaciji iAs, kar je bilo prej opaženo pri populacijah, ki živijo v okoljih, močno onesnaženih z iAs. Poleg tega smo opazili potencialno pomemben vpliv SNP-jev v MTHFR, INMT, MT2A, AQP4, AQP9 in SELENOP na presnovo iAs, pri čemer so bili SNP-ji v zadnjih treh genih prvič proučevani v povezavi s človeškim metabolizmom iAs. Z vključitvijo populacij v različnih fizioloških stanjih (tj. nosečnost in otroštvo) smo poudarili tudi vpliv fiziologije pri preučevanju gensko-okoljskih interakcij.
Genetic susceptibility to inorganic arsenic (iAs) has been predominantly studied in occupational settings and populations with high environmental exposure. Therefore, we assessed the influence of genetic predisposition, based on 15 single nucleotide polymorphisms (SNPs) in 7 genes, on iAs metabolism in Slovenian-Croatian pregnant and nonpregnant women and children, characterised by low iAs exposure. We reported a significant role of a specific AS3MT SNP haplotype in more efficient iAs methylation, a relationship previously observed in populations residing in highly iAs-polluted environments. Additionally, a potentially important influence of MTHFR, INMT, MT2A, AQP4, AQP9, and SELENOP SNPs in iAs metabolism was observed, with SNPs in the latter three genes being studied in relation to human iAs metabolism for the first time. By including populations at different physiological states (i.e., pregnancy, and childhood), we also highlighted the influence of physiology in the assessment of gene-environment interactions.
Povezave polimorfimzmov posameznega nukleotida (SNP) v 7 genih povezanih z metilacijo anorganskega arzena (iAs) pri nosečih in nenosečih ženskah ter otrocih z nizko izpostavljenostjo iAs.
Association of single nucleotide polymorphisms (SNP) in studied 7 genes with inorganic Arsenic (iAs) methylation efficiency in pregnant and nonpregnant women and children with low exposure to iAs.
Lidija Strojnik
Pristnost in sledljivost živil in arom za živila z uporabo stabilnih izotopov lahkih elementov
Authenticity and traceability of food and food flavourings using a stable isotope approach
Mentor in somentor / Supervisor and Co-Supervisor: Nives Ogrinc
Doktorska disertacija se osredotoča na vzpostavitev ustreznega sistema za določanje pristnosti in sledljivosti živil. Ta vključuje razvoj in validacijo ustreznih metod, vzpostavitev podatkovne zbirke reprezentativnih, pristnih vzorcev in razvoj modelov za preverjanje ustreznosti označbe živil. Izpostaviti velja predvsem dva vidika raziskav, ki jih je L. Strojnik razvila in predstavljajo inovativen pristop pri vzpostavitvi sistema sledljivosti. Prvi je razvoj, optimizacija in validacija robustnih analitičnih tehnik primernih za preverjanje pristnosti arom z uporabo ekstrakcijske metode HS-SPME v kombinaciji z GC-IRMS. Drugi del pa se nanša na analizo podatkov in interpretacijo rezultatov. L. Strojnik je ugotovila, da je metoda DD-SIMCA najbolj primerna pri določitvi ali vzorec s tržišča ustreza njegovi označbi porekla (v našem primeru “slovensko poreklo”). Pristop, ki ga je L. Strojnik razvila v okviru doktorske disertacije predstavlja odlično podlago za preverjanje pristnosti v realni uporabi in je primerna tudi za druga živila.
This PhD thesis focuses on the establishment of an appropriate system for the authentication and traceability of foodstuffs. This includes the development and validation of appropriate methods, the establishment of a database of representative, authentic samples and the development of models to verify the correct labelling. Two aspects of the research developed by L. Strojnik are particularly innovative in establishing a traceability system. The first innovation is the development, optimization, and validation of robust analytical techniques for flavor authentication using the HS-SPME extraction method combined with GC-IRMS. The second innovation involves data analysis and interpretation of results. L. Strojnik found that the DD-SIMCA method is the most suitable for determining whether a market sample corresponds to its designated origin (in this case, ‘Slovenian origin’). The approach developed in this PhD thesis provides an excellent basis for authentication in real-life applications and is applicable to other foodstuffs.
Preverjanje geografskega porekla jagod s slovenskega tržišča s pomočjo analize stabilnih izotopov in elementne sestave ter statističnega modeliranja.
Verification of geographical origin of strawberries from Slovenian market using stable isotope and multi-elemental analysis and statistical modeling.
Martina Štampar
Razvoj novih in vitro 3D celičnih modelov za določanje genotoksičnosti
Development of novel 3D in vitro cell models for genotoxicity assessment
Mentor in somentor / Supervisor and Co-Supervisor: Bojana Žegura
Dr. Martina Štampar v je v okviru svojega doktorskega dela razvijala nove jetrne in vitro 3D celične modele (t.i. sferoide), ki imajo izboljšane jetrne funkcije. Pod mentorstvom prof. dr. Bojane Žegura so bile raziskave osredotočene na razvoj statičnih in dinamičnih pogojev, vključno z najsodobnejšo CelVivo tehnologijo z bioreaktorji, za gojenje sferoidov in vitro, ki smo jih uporabili za preučevanje genotoksične aktivnosti kemikalij. Kot pionirji smo bili med prvimi, ki smo te inovativne modele uporabili na področju genetske toksikologije, saj predstavljajo alternativo testiranju na živalih v skladu s 3R (iz angl., reduce, replace, refine) strategijo. V raziskavah je dr. Štampar uporabila več testov za zaznavanje genotoksičnosti različnih snovi, kot so test komet, določanje DNA dvoverižnih prelomov s testom ℽH2AX, konfokalno mikroskopijo za preučevanje številnih celilčnih biomarkerjev v sferoidih. Poleg tega je uporabila toksikogenomski pristop za proučevanje mehanizmov delovanja genotoksičnih spojin ter številne druge metode. Z raziskavami smo pokazali, da novo razviti jetrni 3D celični modeli zaradi svoje bolj kompleksne strukture in izboljšane presnovne sposobnosti, zagotavljajo primeren eksperimentalni model za študije genotoksičnosti kot tudi regulatorno testiranje novih kemikalij in izdelkov. Novi jetrni 3D celični modeli nakazujejo možnost premostitve vrzeli med raziskavami in vitro in študijami na živalih.
Dr. Martina Štampar during her PhD developed cutting-edge hepatic in vitro 3D cell models (spheroids) with enhanced liver-specific characteristic. Under the mentorship of prof. dr. Bojana Žegura, her research focused on the development of static and dynamic conditions, including state-of-the-art CelVivo technology using bioreactors, for cultivating in vitro spheroids that were used for the assessment of genotoxic activity of chemicals. As pioneers, we were among the first to apply these innovative models in the field of genetic toxicology, providing an alternative to animal testing in alignment with the 3R (reduce, replace, refine) strategy. Within the research, dr. Štampar has used several assays to detect (geno)toxicity of various substances, such as the comet assay, detection of DNA double strand breaks with the ℽH2AX assay, the confocal microscopy to study several cell biomarkers in spheroids. In addition, she used a toxicogenomic approach to study the mechanisms of action of genotoxic compounds, and many other methods. Our research has shown that the newly developed hepatic 3D cell models, due to their more complex structure and improved metabolic capacity, provide a suitable experimental model for genotoxicity studies as well as the regulatory testing of new chemicals and products. The 3D cell models have the potential to bridge the gap between in vitro and animal studies.
Novi pristop za testiranje genotoksičnosti na 21-dni starih sferoidih, ki smo jih pripravili iz človeških celic hepatocelularnega karcinoma (HepG2/C3A) z uporabo dinamičnega bioreaktorskega sistema (CelVivo BAM/ bioreaktor). Sferoide smo izpostavili necitotoksičnim koncentracijam posredno delujočih genotoksičnih spojin, kot sta policiklični aromatski ogljikovodik [PAH; benzo(a)piren B(a)P] in heterociklični aromatski amin [PhIP]) in nato poškodbe DNA ocenili s testom komet ter na transkriptomskem nivoju s pomočjo qPCR preučili izražanje izbranih genov, ki kodirajo presnovne encime iz I in II faze, ter genov, ki se odzivajo na poškodbe DNA.
A new approach for genotoxicity testing with 21-day old spheroids formed from human hepatocellular carcinoma cells (HepG2/C3A) using the dynamic clinostat bioreactor system (CelVivo BAM/bioreactor) is presented. The spheroids were exposed to indirect-acting genotoxic compounds, polycyclic aromatic hydrocarbon [PAH; benzo(a)pyrene B(a)P], and heterocyclic aromatic amine [PhIP]) at non-cytotoxic concentrations and subsequently DNA damage was assessed using the comet assay and the mRNA level of selected genes encoding metabolic enzymes from phase I and II, and DNA damage responsive genes was determined using qPCR.
Žiga Tkalec
Razvoj in uporaba netarčne analize za oceno izpostavljenosti kemikalijam v humanem biomonitoringu in sorodnih študijah
Development and application of a non-targeted screening workflow for chemical exposure assessment in human biomonitoring and related studies
Mentor in somentor / Supervisor and Co-Supervisor: Tina Kosjek
S humanim biomonitoringom (HBM) pridobivamo podatke o obsegu in količini človeške izpostavljenosti kemikalijam. Sledenje izpostavljenosti je zelo pomembno, saj številne kemikalije negativno vplivajo na zdravje ljudi. Klasičen pristop omogoča sledenje vnaprej izbranim kemikalijam z dokazanimi neželenimi učinki, izključi pa tiste, o katerih vemo bistveno manj, četudi so morda zdravju bolj nevarne. V svojem doktorskem delu se je Žiga Tkalec osredotočil na razvoj analizne metodologije, ki omogoča celostno sledenje izpostavljenosti znanim, kot tudi (še) neznanim kemikalijam. V dokaz koncepta je analiziral urin slovenskih otrok in določil 74 biomarkerjev izpostavljenosti. S tem je pokazal, da je človek izpostavljen pričakovanim kemikalijam, pa tudi tistim, o katerih se doslej še ni poročalo. Rezultati kažejo na velik obseg izpostavljenosti otrok, med drugim tudi kemikalijam, ki resno ogrožajo zdravje. Ta dosežek je zato pomemben za razvoj HBM, prispeva pa tudi k informiranju javnega zdravja.
Human biomonitoring (HBM) provides crucial data on the extent and amount of human exposure to chemicals. Tracking exposure is vital because many chemicals have negative effects on human health. The classical approach to HBM focuses on tracking pre-selected chemicals with known adverse effects, but it excludes many substances about which we know less, even though they may be more dangerous to health. In his doctoral research, Žiga Tkalec developed an analytical methodology that enables comprehensive tracking of exposure to both known and unknown chemicals. As a proof of concept, he analyzed the urine of Slovenian children and identified 74 exposure biomarkers, revealing that humans are exposed to expected chemicals as well as to previously unreported ones. The results highlight a high level of exposure among children, including to chemicals that pose serious health threats. His achievement is significant for the advancement of HBM providing critical information on chemical exposure.
Uporaba nove analizne metodologije v humanem biomonitoringu, s katero smo odkrili 74 biomarkerjev izpostavljenosti v urinu slovenskih otrok.
The use of a new analytical methodology in human biomonitoring that enabled the determination of 74 biomarkers of exposure in the urine of Slovenian children.
Eva Valenčič
Uporaba informacijskih in komunikacijskih tehnologij, podatkov in znanja za povečanje vpliva digitalnih okolij na izbiro živil
Use of information and communication technologies, data and knowledge to increase the impact of digital environments on food choice
Mentor in somentor / Supervisor and Co-Supervisor: Barbara Koroušić Seljak, Tamara Bucher, Emma Beckett, Clare Elizabeth Collins
Dvojna doktorska disertacija ima dva cilja: oblikovanje digitalnih okolij za potrošnike z uporabo strategij spodbujanja ter zagotavljanje zanesljivih podatkov o hrani in prehrani za arhitekte odločevalce. Izvedene so bile štiri študije: pregled obstoječih raziskav na temo digitalnega spodbujanju v spletnih trgovinah z živili; raziskava vpliva oblikovne zasnove mobilnih aplikacij na izbiro prigrizkov; razvoj uporabniku prijaznega spletnega orodja za učinkovit dostop do podatkov; ter eksperimentalna spletna trgovina, kjer so bili izdelki urejeni glede na vsebnost prehranskih vlaknin, kar je pokazalo učinkovitost strategije digitalnega spodbujanja k bolj zdravim izbiram, z integracijo podatkov in oblikovanja. Ključna ugotovitev je, da učinkovita digitalna okolja zahtevajo večplastni pristop: oblikovanje vmesnikov, ki spodbujajo bolj zdrave izbire prek strategij spodbujanja ter zagotavljanje zanesljivih, integriranih in dostopnih podatkov za arhitekte odločevalce.
This dual PhD dissertation has two aims: designing supportive digital environments for consumers using nudging strategies, and providing accurate food and nutrition data for choice architects. Four studies were conducted: a scoping review of digital nudging in online grocery stores, revealing few implemented strategies and lack of detailed design descriptions; an investigation of mobile app design elements on snack choices, showing background images influenced decisions; the development of a user-friendly web tool for efficient data access; and an experimental online grocery store repositioning products by dietary fiber content, demonstrating effective promotion of healthier choices through integrated data and design. The key finding is that effective digital environments need a multi-faceted approach: designing interfaces that promote healthier choices via nudging, and providing choice architects with reliable, integrated, and accessible data. This ensures well-informed design decisions.
Primer vključitve kategorije sadja in zelenjave v eksperimentalno spletno trgovino z intervencijo (A) in živil za kuhanje v primerjalno eksperimentalno spletno trgovino (B). Za vsak izdelek je prikazana cena glede na količino, ki je navedena v zgornjem levem kotu (npr. EA pomeni ‘kos’). Opomba: slika mešanice za palačinke je bila ustvarjena z uporabo orodja DALL-E.
An example of the Fruits and Vegetables category as it appeared in the intervention experimental online store (A) and of Pantry category as it appeared in the comparator experimental online store (B). For each of the products, the displayed price is related to the quantity indicated in the upper left corner (e.g., EA means ‘each’). Note: the image of the pancake mix was created using DALL-E.
Taja Verovšek
Določanje dovoljenih in nedovoljenih drog v odpadnih in okoljskih vodah: epidemiološki in okoljski vidik
Licit and illicit drugs in waste- and environmental waters: epidemiological and environmental implications
Mentor in somentor / Supervisor and Co-Supervisor: Ester Heath
Z analizo odpadne vode smo preučevali pojavnost NPS v izobraževalnih ustanovah. V raziskavo so bili vključeni vzorci odpadne vode iz osnovnih in srednjih šol ter visokošolskih zavodov. Vzorci so bili analizirani s tekočinsko kromatografijo sklopljeno z masno spektrometrijo (ion mobility-high-resolution mass spectrometry, LC-IMS-HRMS). V raziskavi smo identificirali NPS na treh stopnjah zaupanja (1. stopnja: nedvoumno, 2. stopnja: verjetno, 3. stopnja: pogojno) na osnovi “suspect screening” seznama s 5600 vnosi spojin. NPS smo identificirali v vseh vrstah izobraževalnih ustanovah. Najbolj razširjeni NPS so bili sintetični stimulansi, razkrili smo tudi potencialne prostorske trende, ne pa medinstitucionalnih trendov. Študija kot dokaz koncepta kaže, da je “suspect screening” odpadne vode z LC-IMS-HRMS uporaben za spremljanje pojavnosti NPS v izobraževalnih ustanovah.
We investigated the occurrence of new psychoactive substances (NPS) in educational institutions through wastewater analysis. The study included eight wastewater samples from primary and secondary schools and higher educational institutions. Samples were screened using liquid chromatography-ion mobility-high-resolution mass spectrometry (LC-IMS-HRMS), and NPS identified at three levels of confidence (Level 1: unequivocal, Level 2: probable, Level 3: tentative) from a suspect list containing over 5600 entries. NPS were identified in all types of educational institutions and most prevalent were synthetic stimulants revealing potential spatial but no inter-institutional trends. The study, as a proof-of-concept, demonstrates that a suspect screening of wastewater employing LC-IMS-HRMS can be used as a radar for NPS in educational institutions.
Preučevanje pojavnosti novih psihoaktivnijh snovi v izobraževalnih institucijah na osnovi analize odpadne vode.
Screening for new psychoactive substances in wastewater from educational institutions.
Janja Vidmar
Določanje koncentracije in velikosti kovinskih nanodelcev v okoljskih in bioloških vzorcih
Quantification and sizing of metal-based nanoparticles in the environmental and biological samples
Mentor in somentor / Supervisor and Co-Supervisor: Radmila Milačič, Janez Ščančar
V sodelovanju z raziskovalci Zavoda za gradbeništvo Slovenije smo pokazali, da je uporaba nanodelcev nič-valentnega železa (nZVI) učinkovita pri čiščenju odpadne vode iz male biološke čistilne naprave. Vendar po njihovi uporabi obstaja tveganje, da nZVI ostanejo dispergirani v vodi in tako predstavljajo nevarnost za okolje. Z namenom, da tovrstno nevarnost ocenimo smo preučevali obnašanje nZVI in njihove interakcije s Cd2+ po čiščenju vod z različnimi začetnimi koncentracijami nZVI. Optimizirali smo novo metodo masne spektrometrije z induktivno sklopljeno plazmo v t.i. single particle načinu (SP-ICP-MS), ki omogoča merjenje nZVI v različnih vzorcih vode brez interferenc merjenja in pri visoki občutljivosti. Rezultati so pokazali, da imajo lastnosti vodnih matric velik vpliv na hitrost agregacije in posedanja nZVI. V odpadni vodi se nZVI najhitreje posedajo in s tem posledično najbolj učinkovito odstranijo Cd2+. Po sedmih dneh usedanja so v odpadni vodi ostale nizke koncentracije nZVI, kar potrjuje, da je uporaba nZVI za nanoremediacijo odpadne vode varna in ne predstavlja nevarnosti za okolje.
In collaboration with researchers from the Slovenian National Building and Civil Engineering Institute National Building Institute, we proved that the use of nanoparticles of zero-valent iron (nZVI) is effective in cleaning wastewater from a small biological treatment plant. However, after their use, nZVI may persist in the remediated water, representing potential nano-threats. Therefore, the behaviour of nZVI and their interactions with Cd2+ after remediation with different Fe loads and in different water matrices were studied to estimate such risk. A novel method using single particle inductively coupled plasma mass spectrometry (SP-ICP-MS) was optimized for sensitive and interference-free measurement of nZVI in environmental water matrices. The results showed that nZVI sedimentation and aggregation strongly depend on water matrix. In wastewater, nZVI settle the fastest and thus remove Cd2+ most efficiently. After seven days of settling, negligible concentrations of nZVI remained in the effluent wastewater, which confirms that the use of nZVI for wastewater remediation is safe and does not represent environmental nano-threat.
Obnašanje nanodelcev nič-valentnega železa (nZVI) in njihove interakcije s Cd2+ v odpadnih vodah, ki smo mu sledili z uporabo SP-ICP-MS metode.
Investigation of the behaviour of nZVI and their interactions with Cd2+. in wastewater by single particle ICP-MS.
Janja Vrzel
Študija interakcij med površinsko in podzemno vodo v vodonosnem sistemu Ljubljansko polje (Slovenia)
Surface-groundwater interactions of Ljubljansko polje aquifer system (Slovenia)
Mentor in somentor / Supervisor and Co-Supervisor: Nives Ogrinc, Ralf Ludwig. Goran Vižintin
Doktorska disertacija Janje Vrzel zajema proučevanje hranil ter hidrogeokemijskih značilnosti reke Save in podzemne vode v vodonosnem sistemu Ljubljansko polje z uporabo stabilnih izotopov lahkih elementov in hidrološkega modeliranja. Glavni namen je bil identificiranje stresorjev ter njihov vpliv na obe vodni telesi in na procese, ki potekajo med njima. Interdisciplinarni pristop je omogočil identifikacijo ranljivih območij omenjenega vodonosnega sistema in kvantifikacijo zadrževalnih časov tamkajšnje podzemne vode. Raziskave so bile še nadgrajene s simulacijo hidroloških procesov za obdobje 2036-2065, kar je omogočilo proučevanje vpliva klimatskih sprememb na vodni krog na Ljubljanskem polju. Tako sami rezultati, kot razvito unikatno modelno orodje so v prihodnosti lahko v pomoč pri sprejemanju ukrepov za zaščito vode in strategij za upravljanje z vodnimi viri. To je za Ljubljansko polje, ki predstavlja glavni vir pitne vode za Ljubljano in okolico, še posebej pomembno.
Janja Vrzel’s PhD thesis focuses on the study of nutrients and hydrogeochemical characteristics of the Sava River and groundwater in the Ljubljansko polje aquifer system, utilizing stable isotopes of light elements and hydrological modelling. The primary objective was to identify stressors and their impacts on these two water bodies and the processes between them. This interdisciplinary approach enabled the identification of vulnerable areas within the aquifer system and the quantification of groundwater residence times. The research was further enhanced by simulating hydrological processes for the period 2036-2065, which allowed for the study of climate change impacts on the water cycle in the Ljubljansko polje. The results and the unique modelling tool developed through this research can aid in future water protection measures and water resource management strategies. This is particularly important for the Ljubljansko polje, as it is the main source of drinking water for Ljubljana and its surrounding areas.