11. Digital PCR method for detection and quantification of specific antimicrobial drug-resistance mutations in human cytomegalovirusAlexandra Bogožalec Košir, Tašja Cvelbar, Martin Kammel, Hans-Peter Grunert, Heinz Zeichhardt, Mojca Milavec, 2020, original scientific article Abstract: Antimicrobial drug resistance is one of the biggest threats to human health worldwide. Timely detection and quantification of infectious agents and their susceptibility to antimicrobial drugs are crucial for efficient management of resistance to antiviral drugs. In clinical settings, viral drug resistance is most often associated with prolonged treatment of chronic infections, and assessed by genotyping methods; e.g., sequencing and PCR. These approaches have limitations: sequencing can be expensive and does not provide quantification; and qPCR quantification is hampered by a lack of reference materials for standard curves. In recent years, digital PCR has been introduced, which provides absolute quantification without the need for reference materials for standard curves. Using digital PCR, we have developed a rapid, sensitive and accurate method for genotyping and quantification of the most prevalent mutations that cause human cytomegalovirus resistance to ganciclovir. Keywords: digital PCR, antimicrobial-drug resistance, HCMV, polymerase chain reaction, viruses Published in DiRROS: 22.07.2024; Views: 125; Downloads: 105 Full text (5,71 MB) This document has many files! More... |
12. CRISPR/Cas9-mediated fine-tuning of miRNA expression in tetraploid potatoTjaša Lukan, Florian Veillet, Maja Križnik, Anna Coll Rius, Tjaša Mahkovec Povalej, Karmen Pogačar, Katja Stare, Laura Chauvin, Jean-Eric Chauvin, Kristina Gruden, 2022, original scientific article Abstract: MicroRNAs (miRNAs) are small noncoding RNAs, which modulate the abundance and spatiotemporal accumulation of target mRNAs at transcriptional and post-transcriptional levels and through that play important roles in several biological processes in plants. Here we show that in polyploid species, CRISPR/Cas9 system can be used for fine-tuning of miRNA expression, which can have broader range of applications compared to knock-out mutants. We established the complete pipeline for CRISPR-Cas9-mediated modulation of miRNA expression in potato. It consists of (1) design and assembly of dual sgRNA CRISPR/Cas9 constructs, (2) transient transfection of protoplasts following fast and efficient screening by high resolution melting analysis to select functional sgRNAs, and (3) stable transformation of potato explants with functional sgRNAs and selection of regenerated transgenic lines with desired mutations and desired miRNA abundance based on sequencing and RT-qPCR. We show that miRNA-editing using dual sgRNA approach results in different types of mutations among transgenic lines but also in different alleles of the same plant, which are target site-dependent. The most frequent were short deletions, but we also detected 1-nt insertions (T or G), deletions between two sgRNAs and larger deletions. miRNA abundance correlates with the frequency and type of introduced mutations, as more extensive mutations in more alleles result in lower miRNA abundance. Interestingly, some mutated loci can generate alternative miRNAs, now novel targets were however predicted for those. In all transgenic lines with Cas9 expression, we detected mutations, suggesting high efficiency of Cas9-editing. We confirmed the miRNA-editing efficiency of our optimised approach in two different potato genotypes and three different loci. Keywords: CRISPR/Cas9, hypersensitive response (HR)-conferred resistance, immune signaling, live cell imaging, Solanum tuberosum (potato), spatiotemporal analysis, stromules, virus resistance Published in DiRROS: 17.07.2024; Views: 130; Downloads: 136 Full text (2,94 MB) This document has many files! More... |
13. Pharmacogenomic markers of glucorticoid responses in the initial phase of remission induction therapy in childhood acute lymphoblastic leukemiaVladimir Gasic, Branka Zukic, Biljana Stanković, Dragana Janić, Lidija Dokmanovic, Jelena Lazic, Nada Krstovski, Vita Dolžan, Janez Jazbec, Sonja Pavlovič, Nikola Kotur, 2018, original scientific article Keywords: pharmacogenomics, childhood ALL, glucocorticoids, glucocorticoid receptor gene, glutathione S-transferase genes, multidrug resistance 1 gene Published in DiRROS: 11.06.2024; Views: 156; Downloads: 55 Full text (339,19 KB) |
14. Identification of epigenetically regulated genes involved in plant-virus interaction and their role in virus-triggered induced resistanceRégis L. Corrêa, Denis Kutnjak, Silvia Ambrós, Mónica Bustos, Santiago F. Elena, 2024, original scientific article Abstract: Background: Plant responses to a wide range of stresses are known to be regulated by epigenetic mechanisms. Path-ogen-related investigations, particularly against RNA viruses, are however scarce. It has been demonstrated that Arabi-dopsis thaliana plants defective in some members of the RNA-directed DNA methylation (RdDM) or histone modi-fication pathways presented differential susceptibility to the turnip mosaic virus. In order to identify genes directly targeted by the RdDM-related RNA Polymerase V (POLV ) complex and the histone demethylase protein JUMONJI14 (JMJ14) during infection, the transcriptomes of infected mutant and control plants were obtained and integrated with available chromatin occupancy data for various epigenetic proteins and marks. Results: A comprehensive list of virus-responsive gene candidates to be regulated by the two proteins was obtained. Twelve genes were selected for further characterization, confirming their dynamic regulation during the course of infection. Several epigenetic marks on their promoter sequences were found using in silico data, raising confidence that the identified genes are actually regulated by epigenetic mechanisms. The altered expression of six of these genes in mutants of the methyltransferase gene CURLY LEAF and the histone deacetylase gene HISTONE DEACETYLASE 19 suggests that some virus-responsive genes may be regulated by multiple coordinated epigenetic complexes. A temporally separated multiple plant virus infection experiment in which plants were transiently infected with one virus and then infected by a second one was designed to investigate the possible roles of the identified POLV- and JMJ14-regulated genes in wild-type (WT ) plants. Plants that had previously been stimulated with viruses were found to be more resistant to subsequent virus challenge than control plants. Several POLV- and JMJ14-regulated genes were found to be regulated in virus induced resistance in WT plants, with some of them poisoned to be expressed in early infection stages. Conclusions: A set of confident candidate genes directly regulated by the POLV and JMJ14 proteins during virus infection was identified, with indications that some of them may be regulated by multiple epigenetic modules. A sub-set of these genes may also play a role in the tolerance of WT plants to repeated, intermittent virus infections.Keywords Biotic stress, Defense priming, Epigenetics, Histone modifications, Induced resistance, Potyvirus, RNA-directed DNA methylation. Keywords: biotic stress, defense priming, epigenetics, histone modifications, induced resistance, Potyvirus, RNA-directed DNA methylation Published in DiRROS: 17.05.2024; Views: 321; Downloads: 947 Full text (6,66 MB) This document has many files! More... |
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16. Treatment of condensation in sandwich panels without known vapour resistance of sealantGregor Vidmar, 2020, published scientific conference contribution Abstract: In order to calculate amount of interstitial condensation in a building envelope, water vapour resistance of each layer is of importance. Once having it, 1D calculation according to ISO 13788 with monthly average vapour pressures can be applied. In EN 14509 sandwich panels are considered to be impermeable for water vapour, thus (according to the standard) water vapour cannot enter from outside and condensate in the panels. But it is not always true for real sandwich panels, because joints between neighbouring panels can cause non-neglecting water vapour bridges. Although in measurements of linear water vapour transmittance of the joints (Ψv) stationary boundary vapour pressures can be applied, the measurements can be long lasting. We shortened time needed to get Ψv performing simulations in Delphin6.0. We simulated panels and steel sheets with joints using constant boundary vapour pressures and compared the results with the results of measurements on the equivalent systems.
In systems under consideration a sealant in built-in-state, located at a joint of a sandwich panel, is a compressed EPDM tube. It is impossible to directly measure its effective μ according to ISO 12572. In the paper we study to which precision it is possible to determine it using measurements and simulations. Once having effective μ of the sealant (if all other necessary material parameters available) one can simulate condensation in envelopes including sandwich panels in 2D according to EN 15026 using hourly climatic data. Another goal of the study was determination of differences in resulting Ψv values when varying narrowest part of the gap dGAP at the joint in the panels without any sealant. Results confirm significant sensibility of Ψv to variations of dGAP. Keywords: water vapour condensation, water vapour diffusion, numerical simulations, water vapour resistance, linear water vapour transmittance, sendwich panels Published in DiRROS: 05.03.2024; Views: 336; Downloads: 222 Full text (2,11 MB) This document has many files! More... |
17. Influence of precipitation hardening on the mechanical properties of Co-Cr-Mo and Co-Cr-W-Mo dental alloysMarko Sedlaček, Katja Zupančič, Barbara Šetina, Borut Kosec, Matija Zorc, Aleš Nagode, 2023, original scientific article Keywords: Co-Cr alloys, microstructure analysis, hardness, wear resistance Published in DiRROS: 01.02.2024; Views: 424; Downloads: 232 Full text (53,05 MB) This document has many files! More... |
18. Predicting the quality of grain refiners from electrical resistance measurements of aluminumMaja Vončina, Irena Paulin, Jože Medved, Mitja Petrič, 2023, original scientific article Keywords: Al-Ti-B grain-refiners, quality, TiB2 particles, Al3Ti particles, electrical resistance measurements Published in DiRROS: 01.02.2024; Views: 356; Downloads: 172 Full text (8,93 MB) This document has many files! More... |
19. Ultra-high strenght TWIP steel with high chromium contentPavel Podaný, Tomáš Studecký, Tomas Gregor, Radek Prochazka, Aleksandra Kocijan, 2023, original scientific article Abstract: A new ultra-high strength steel with a fully austenitic microstructure and twinning-induced plasticity (TWIP) effect has been developed. TWIP effect gives this steel a good combination of high strength of over 1000 MPa and ductility of over 35%. This new steel has a high chromium content, which increases its corrosion resistance. By combining cold rolling and annealing, the steel has achieved a very fine austenitic microstructure with an average grain diameter of 2.85 µm. This steel could be used for structural applications or components that need to withstand high levels of stress, deformation and corrosion environment. Keywords: TWIP steels, corrosion resistance, microstructure, tensile strength, plasticity Published in DiRROS: 31.01.2024; Views: 405; Downloads: 229 Full text (1,44 MB) This document has many files! More... |
20. Improving the surface properties of additive-manufactured Inconel 625 by plasma nitridingDanijela Anica Skobir Balantič, Črtomir Donik, Bojan Podgornik, Aleksandra Kocijan, Matjaž Godec, 2023, original scientific article Abstract: As a surface-hardening technique, plasma nitriding is a common procedure for improving the properties of
conventional Ni-based alloys. The diffusion of nitrogen hardens a layer on the surface of the alloy, leading to
better wear resistance and a higher coefficient of friction, as well as a higher surface hardness. This study reports
the effect of plasma nitriding on additive-manufactured (AM) Inconel 625 (IN625) compared to its conventional
manufactured and nitrided counterparts. The samples produced with the laser powder-bed fusion (LPBF) process
were subsequently plasma nitrided in the as-built condition, stress-relief annealed at 870 °C and solution treated
at 1050 °C. The plasma nitridings were carried out at 430 °C and 500 °C for 15 h. The growth kinetics of the
nitride layer of the AM samples depends on the prior heat treatments and is faster in the as-built state due to the
specific cellular structure. The lower nitriding temperature leads to the formation of expanded austenite in the
nitride layer, while at the higher nitriding temperature, the expanded austenite decomposes and CrN precipitation
occurs. The XRD and SEM analyses confirmed the presence of two layers: the surface layer and the
diffusion layer beneath. The lower nitriding temperature caused the formation of expanded austenite or a
combination of expanded austenite and CrN. The higher nitriding temperature led to the decomposition of the
expanded austenite and to the formation/precipitation of CrN. The higher nitriding temperature also decreased
the corrosion resistance slightly due to the increased number of precipitated Cr-nitrides. On the other hand, the
wear resistance was significantly improved after plasma nitriding and was much less influenced by the nitriding
temperature. Keywords: additive manufacturing, powder-bed fusion, plasma nitriding, expanded austenite, wear and corrosion resistance, Ni-based alloy Published in DiRROS: 31.01.2024; Views: 418; Downloads: 154 Full text (7,98 MB) This document has many files! More... |