941. Melanoma antigens in pediatric medulloblastoma contribute to tumor heterogeneity and species-specificity of group 3 tumorsRebecca R. J. Collins, Rebecca R. Florke Gee, Sima Tozandehjani, Tara Bayat, Maria Camila Hoyos Sanchez, Juan Sebastian Solano Gutierrez, Barbara Breznik, Anna K. Lee, Klementina Fon Tacer, 2025, original scientific article Abstract: Medulloblastoma (MB) is the most malignant childhood brain cancer. Group 3 MB (G3 MB) subtype accounts for about 25% of MB and is associated with the worst outcomes. Herein, we report that more than half of G3 MB tumors express melanoma antigens (MAGEs), which are potential prognostic and therapeutic markers. MAGEs are cancer‑testis antigens, aberrantly expressed in several adult cancers, and associated with poorer prognosis and therapy resistance; however, their role in pediatric cancers is mostly unknown. This study aimed to determine whether MAGEs are activated and important in pediatric MB. We obtained formalin‑fixed paraffin‑embedded tumor samples of 34 patients, collected between 2008 and 2015 at the Children’s Medical Center in Dallas and applied our validated reverse transcription quantitative PCR (RT‑qPCR) assay to measure the expression of 23 MAGE genes. To validate our data, we analyzed published datasets from pediatric MB tumors and patient‑derived orthotopic xenografts, totaling 949 patients. Our RT‑qPCR analysis suggested that MAGEs were expressed in G3/4MB. Further mining of bulk and single‑cell RNA‑sequencing datasets confirmed that 50–75% of G3 tumors activate several MAGEs. Intriguingly, single‑cell data analysis showed that MAGEs are expressed in distinct subsets of cells in MAGE‑positive tumors and are not activated in mouse genetic models, suggesting they contribute to the tumor heterogeneity and species‑specificity of G3 MB. We then examined how MAGE expression affects the growth and oncogenic potential by CRISPR‑Cas9‑ and siRNA‑mediated gene depletion. Depletion of MAGEAs, ‑B2, and ‑Cs altered cell survival, viability, and clonogenic growth due to decreased proliferation and increased apoptosis of MAGE‑positive MB cells. These findings suggested that targeting MAGEs could represent a viable therapeutic strategy for G3 MB. A deeper understanding of MAGE regulation and function is warranted and could aid in improving prognostic and therapeutic approaches for this poorly characterized subgroup of pediatric brain tumors.
Keywords: medulloblastoma, tumor antigens, MAGE, pediatric cancer, cancer‑testis antigens
Published in DiRROS: 19.09.2025; Views: 305; Downloads: 138
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942. Transformative change and a sustainable worldJuan Martin Dabezies, Teresia Olemako, Jerneja Penca, Asha Rajvanshi, Roseline Remans, Esther Turnhout, Yuki Yoshida, 2025, independent scientific component part or a chapter in a monograph Keywords: biodiversity, justice, transformative change, sustainability
Published in DiRROS: 19.09.2025; Views: 265; Downloads: 115
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943. Re-evaluating restrained shrinkage tests for sustainable sprayed concrete tunnel liningsZhongyu Xu, Lucija Hanžič, Harry Asche, Jurij Karlovšek, 2025, published scientific conference contribution Abstract: The demand for tunnelling and underground construction is steadily increasing, alongside growing considerations for carbon emission reduction in tunnelling projects. Using sprayed concrete as a prominent ground support mechanism for the sequential excavation method is also undergoing low-carbon transition with improved resource efficiency. Enhancing the durability of sprayed concrete linings for structural support and water tightness is essential, particularly when used as a permanent lining, replacing conventional cast in-situ concrete for a design life exceeding 100 years. As sprayed concrete is a time-dependent material used in a time-dependent tunnelling environment, restrained shrinkage cracking in tunnel linings is a recognised issue, especially in mined tunnels in shallow or hard-rock ground with minimal ground movement. The susceptibility of sprayed concrete to restrained shrinkage cracking poses challenges to low-carbon transition, impacting the efficacy and longevity of tunnel linings. Excessive crack widths in tunnel projects often lead to non-conformances, requiring time-consuming repairs and affecting project delivery. However, current design methods for permanent sprayed concrete linings inadequately consider the effects of restrained shrinkage, particularly with sprayed concrete containing reinforcement fibres and accelerators. This paper examines the features that should be included in the restrained shrinkage test for tunnel lining applications, and proposes an improvement in detecting crack initiation and determining the optimal number of measurement points form when multiple cracks form with a finite element analysis. The analysis results showed the possibility of detecting the onset of cracking and crack location with multiple measurement points by interpreting the response of each measurement point.
Keywords: tunnel linings, sprayed concrete, restrained shinkage, large ring test
Published in DiRROS: 19.09.2025; Views: 335; Downloads: 138
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944. Asymmetric T-segment binding and gate dynamics govern the final stages of the type IIA topoisomerase catalytic cycleKristina Stevanović, Barbara Herlah, Matic Pavlin, Andrej Perdih, 2025, original scientific article Abstract: Type IIA DNA topoisomerases are molecular nanomachines that alter DNA topology during essential cellular processes. The final steps of their catalytic cycle, after translocation of the transported (T-) segment into the C- gate, are still not fully understood. Here, we performed all-atom molecular dynamics simulations of several conformational states of Saccharomyces cerevisiae topoisomerase IIA, each with a T-segment inserted into the C- gate. Bound ATP and ADP nucleotides allosterically modulated the N-gate dynamics, likely stabilizing the dimer and preventing premature dissociation. The T-segment was asymmetrically bound and stabilized within the C- gate by positively charged residues, and this gate remained structurally rigid, highlighting its role as a retention site. The positioning of the T-segment in the C-gate allosterically influenced the G-segment to a straighter geometry that favors religation and release. Our simulations support coordinated release of DNA segments and point to a potentially important role for dynamic communication between the gates in the mechanism. These results provide new insights into the late stages of the catalytic cycle and highlight the intertwined roles of nucleotide binding, DNA topology and coupled protein domain dynamics in regulating this important enzyme.
Keywords: type IIA DNA topoisomerase, T-segment, C-gate, catalytic cycle, molecular dynamics
Published in DiRROS: 19.09.2025; Views: 342; Downloads: 154
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945. Influence of particle size on powder velocity distribution at the nozzle outlet in Directed Energy DepositionTijan Mede, Andrej Jeromen, Edvard Govekar, Michael Mallon, Matjaž Godec, 2025, original scientific article Abstract: Metal-based Directed Energy Deposition (DED) is considered one of the variations of additive manufacturing with the highest potential, particularly for space industry and in-orbital manufacturing. The technology however still faces various challenges, many of which can be traced back to poor control and understanding of the powder delivery. Velocity distribution of powder particles at the DED nozzle outlet has a key influence on the results of any predictive model of powder stream and yet remains largely disputed. Certain numerical studies highlighted a possible influence of powder particle size on the velocity condition at the nozzle exit, yet no experimental studies confirmed this effect. The experimental campaign described in this paper quantifies this relation between powder particle size and velocity distribution at the nozzle outlet and a strong decrease of particle speed with particle size is observed. Moreover, smaller particles are observed to travel at speeds higher than the mean carrier gas speed suggesting powder particle segregation within the nozzle as one of the mechanisms driving speed differences at the nozzle outlet.
Keywords: directed energy deposition, powder stream, boundary conditions, particle velocity distribution
Published in DiRROS: 19.09.2025; Views: 284; Downloads: 135
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946. Recycling mineral wool waste : towards sustainable construction materialsMartina Milat, Sandra Juradin, Nives Ostojić-Škomrlj, Anže Tesovnik, 2025, review article Abstract: This literature review critically examines the incorporation of mineral wool waste (MWW), a byproduct of insulation materials, into new construction materials as a sustainable recycling strategy. Covering research published between 2000 and 2025, the review focuses on the effects of MWW on various material properties and performance, including concrete, mortar, alkali-activated materials (AAMs), geopolymers (GPs), building ceramics, and asphalt. Experimental evidence demonstrates that MWW can enhance or alter the performance of these materials, offering promising opportunities for waste valorization. The review also identifies challenges related to optimizing material compositions and production methods, and highlights the need for further research to facilitate the industrial-scale application of MWW-recycled construction materials. By synthesizing current knowledge, this work aims to inform sustainable development and circular economy practices in the construction sector.
Keywords: mineral wool waste, rock wool, glass wool, recycling, sustainability, construction and demolition waste
Published in DiRROS: 19.09.2025; Views: 310; Downloads: 146
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947. Catalytically Active Oxidized ▫$PtO_x$▫ Species on ▫$SnO_2$▫ Supports Synthesized via Anion Exchange Reaction for 4-Nitrophenol ReductionIzabela Đurasović, Robert Peter, Goran Dražić, Fabio Faraguna, Rafael Anelić, Marijan Marciuš, Tanja Jurkin, Vlasta Mohaček-Grošev, Maria Gracheva, Zoltan Klencsár, Mile Ivanda, Goran Štefanić, Marijan Gotić, 2025, original scientific article Abstract: An anion exchange-assisted technique was used for the synthesis of platinum-decorated SnO2 supports, providing nanocatalysts with enhanced activity for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). In this study, a series of SnO2 supports, namely SnA (synthesized almost at room temperature), SnB (hydrothermally treated at 180 ◦C), and SnC (annealed at 600 ◦C), are systematically investigated, all loaded with 1 mol% Pt from H2PtCl6 under identical mild conditions. The chloride ions from the SnCl4 precursors were efficiently removed via a strong-base anion exchange reaction, resulting in highly dispersed, crystalline ~5 nm cassiterite SnO2 particles. All Pt/SnO2 composites displayed mesoporous structures with type IVa isotherms and H2-type hysteresis, with SP1a (Pt on SnA) exhibiting the largest surface area (122.6 m2/g) and the smallest pores (~3.5 nm). STEM-HAADF imaging revealed well-dispersed PtOx domains (~0.85 nm), while XPS confirmed the dominant Pt4+ and Pt2+ species, with ~25% Pt0 likely resulting from photoreduction and/or interactions with Sn–OH surface groups. Raman spectroscopy revealed three new bands (260–360 cm−1) that were clearly visible in the sample with 10 mol% Pt and were due to the vibrational modes of the PtOx species and Pt-Cl bonds introduced due the addition and hydrolysis of H2PtCl6 precursor. TGA/DSC analysis revealed the highestmass loss for SP1a (~7.3%), confirming the strong hydration of the PtOx domains. Despite the predominance of oxidized PtOx species, SP1a exhibited the highest catalytic activity (kapp = 1.27 × 10−2 s−1) and retained 84.5% activity for the reduction of 4-NP to 4-AP after 10 cycles. This chloride-free low-temperature synthesis route offers a promising and generalizable strategy for the preparation of noble metal-based nanocatalysts on oxide supports with high catalytic activity and reusability.
Keywords: platinum, SnO2, anion exchange, Dowex 550, catalyst, 4-nitrophenol, 119Sn Mössbauer
Published in DiRROS: 18.09.2025; Views: 324; Downloads: 172
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948. Composite based on nickel-functionalized carbon nitride and carbon nanotubes as an efficient electrocatalyst for the oxygen evolution reactionNicolò Rossetti, Verónica Celorrio, Goran Dražić, Laura Calvillo, 2025, original scientific article Abstract: Single metal atom catalysts (SACs) are receiving widespread attention in electrochemical energy conversion reactions due to the rational use of metal resources and maximum atom utilization efficiency. The role of the support in stabilizing the single atoms is crucial for their catalytic stability. Carbon nitride (CN) is an excellent support for SACs but its low electrical conductivity is not appropriate for electrochemical applications. Here, we report an engineered composite material based on multiwall carbon nanotubes (MWCNTs) and single nickel atoms stabilized on CN (Ni–CN) as efficient and robust electrocatalyst for the oxygen evolution reaction (OER). Composites with different mass Ni–CN:MWCNT ratios have been prepared to optimize the contribution of both materials, and characterized by X-ray diffraction, transmission electron microscopy, X-ray absorption, and X-ray photoemission spectroscopy. Results confirmed the self-assembly of both materials and the condensation of the triazine-based structure of CN into heptazine-based onto the MWCNTs’ surface during the synthesis, as well as the presence of single Ni atoms in the composites. The co-presence of NiO nanoparticles was detected for the samples with the highest Ni content. The ratio of NiO nanoparticles to single-atom Ni centers was governed by the Ni–CN:MWCNT ratio employed during synthesis. Electrochemical characterization showed a synergistic effect between Ni–CN and MWCNTs that boosted the OER activity of the composites respect to the individual components. The 1:2 ratio turned out to be the optimal one for the composite preparation, maximizing the combined effects of the catalytic activity of the Ni centers and the electrical conductivity of MWCNTs. The mass activity obtained by this composite was 30 times higher than that of the Ni–CN starting material, attributable to its superior electrical conductivity and improved accessibility of Ni active sites. This study underscores the potential of composite materials to advance SACs toward large-scale application.
Keywords: carbon nanotubes, carbon nitride, single atom catalysts, nickel oxygen evolution reaction
Published in DiRROS: 18.09.2025; Views: 322; Downloads: 125
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949. Spin glass effects and nonexistence of a ferromagnetic quantum critical point in the compositionally tuned ▫$FeGa_{3−x}Ge_x$▫ metallic quantum ferromagnets (x = 0.0 − 0.16)Stanislav Vrtnik, Primož Koželj, Magdalena Wencka, Kristian Bader, Julia Petrović, Jože Luzar, Peter Mihor, Andreja Jelen, Peter Gille, Janez Dolinšek, 2025, original scientific article Keywords: frustrated magnetism, quantum phase transitions, specific heat, quantum critical point
Published in DiRROS: 18.09.2025; Views: 306; Downloads: 124
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950. Interdisciplinary assessment of children’s lead exposure in residential areas degraded by mining (Upper Meža Valley, Slovenia)Špela Bavec, Teja Čeru, Stanislava Kirinčič, Matej Ivartnik, Viviana Golja, Janja Turšič, Klemen Teran, Miloš Miler, 2025, original scientific article Abstract: Children’s lead exposure in three mining-impacted residential areas (Črna, Mežica and Žerjav) was modelled using the Integrated Exposure Uptake Biokinetic Model for Lead in Children (IEUBK). Site-specific environmental and dietary Pb source values were determined for modelling. For the first time, dietary exposure from both market and local foods was studied in detail. Children (Group 1: 24–36 and Group 2: 36–48 months) geometric mean blood lead levels (BLLs) were predicted and lead uptake from multiple sources was quantified according to the different dietary exposure scenarios. Biomonitoring data were used for validation. Site-specific soil, house dust and local food Pb contents are higher than legislative and background levels, remaining a cause for concern. Drinking tap water concentrations and outdoor air contents were found in acceptable levels. The determined dietary exposures, ranging from 0.7 to 3.3 µg/kg bw/day, were above the benchmark dose level of 0.5 µg/kg bw/day for developmental neurotoxicity set for Pb in children, indicating a health concern. In general, the estimated BLLs matched reasonably well with the observed BLLs in the Črna and Mežica area for both age groups and in the Žerjav area for Group 2. For Group 1, in the Žerjav area, the output of the IEUBK model overestimated the actual BLLs of the children. For both groups, the primary exposure pathway in Žerjav is from soil/dust, ranging from 55.3 to 84.8%. In Črna and Mežica, soil/dust exposure ranged between 24.2 and 57.8% and between 26.4 and 61.7%, respectively, indicating that dietary exposure predominates when local foods are included. The results of our study also suggest that using the IEUBK default diet value would reduce the dietary exposure up to 25.2% in Črna, 24.2% in Mežica and 8.6% in Žerjav. One of the main findings is that a diet containing local foods can be an important source of lead in mining-contaminated areas.
Keywords: IEUBK model, blood lead level, soil, house dust, dietary exposure, risk assessment
Published in DiRROS: 18.09.2025; Views: 315; Downloads: 109
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