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672. Patient-derived tumor organoids mimic treatment-induced DNA damage response in glioblastomaBernarda Majc, Anamarija Habič, Marta Malavolta, Miloš Vittori, Andrej Porčnik, Roman Bošnjak, Jernej Mlakar, Alenka Matjašič, Andrej Zupan, Marija Skoblar Vidmar, Tamara Lah Turnšek, Aleksander Sadikov, Barbara Breznik, Metka Novak, 2024, original scientific article Abstract: Glioblastoma (GB) is the most common primary malignant brain tumor, characterized by resistance to therapy. Despite aggressive treatment options, GB remains an incurable disease. Invasiveness and heterogeneity are key GB features that cannot be studied in preclinical in vitro models. In this study, we investigated the effects of standard therapy using patient-derived GB organoids (GBOs). GBOs reflect the complexity and heterogeneity of the original tumor tissue. No significant effect on GBO viability or invasion was observed after irradiation and temozolomide treatment. E3 ubiquitin-protein ligase (MDM2), cyclin-dependent kinase inhibitor 1A (CDKN1A), and the serine/threonine kinases ATM and ATR were upregulated at the gene and protein levels after treatment. Our results show that the p53 pathway and DNA-damage response mechanisms were triggered, suggesting that GBOs recapitulate GB therapy resistance. GBOs thus provide a highly efficient platform to assess the specific responses of GB patients to therapy and to further explore therapy resistance.
Keywords: cellular physiology, cellular toxicology, in vitro toxicology including 3D culture, technical aspects of cell biology, cancer
Published in DiRROS: 09.09.2024; Views: 370; Downloads: 170
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673. The relationship between the inhalation bioaccessibility of potentially toxic elements in road dust from a heavily polluted industrial area and the source of their pollutionMarija Zupančič, Miloš Miler, Gorazd Žibret, 2024, original scientific article Abstract: One of the sources of chronic exposure to potentially toxic elements (PTE), especially in polluted environments, is the inhalation of resuspended road dust (RD). The aim of this study is to assess the inhalation bioaccessibility of PTE in RD from highly polluted environments from mining/smelting industries and traffic, and to identify any correlations between the bioaccessibility fraction of PTE and the physicochemical characteristics of the particles. RD from the studied area contains extremely high total concentrations of Cr, V, and Mn, which are likely due to pollution from the smelting industry. Additionally, elevated total concentrations of other elements associated with traffic emissions including Zn, Cu, Pb, Sb, and Sn were also measured. The bioaccessibility of PTE was assessed using two synthetic extraction solutions - Gamble's solution (GS) and Artificial Lysosomal Fluid (ALF). The majority of elements showed negligible bioaccessibility in GS. However, quite high inhalation bioaccessibility was observed for Zn, Pb, Sb, Cd, and Mn in the ALF solution, with a mean bioaccessible fraction of 49, 51.5, 41, 50, and 40% respectively. The highest bioavailable fraction was measured for Cd (97%) in a sample collected near a steel production facility and for Pb (95%) in a sample collected near the highway. These results indicate that increased mobility of the elements in inhaled particles occurs only in the case of phagocytosis. The lowest inhalation bioavailability was measured for Cr (mean is 3%). Differential individual particle analysis revealed that about 60% of phases, mostly major (Cr,Ti,V)-bearing metallic alloys, silicates, oxides and sulphides, are stable in ALF solution, while 40% of phases, mostly (Fe,Ca,Mn)-bearing oxides, silicates, sulphides, metals and metallic alloys originating from steel production, ferrochrome, ferrosilicon and vanadium production and from traffic emissions have been heavily corroded or completely dissolved. The study provides valuable information to further assess health hazards from various emission sources.
Keywords: coal mining, inhalation bioaccessibility, mining/smelting pollution, potentially toxic elements, road dust, traffic pollution
Published in DiRROS: 09.09.2024; Views: 359; Downloads: 3270
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674. Ultrasound-mediated spatial and temporal control of engineered cells in vivoFilip Ivanovski, Maja Meško, Tina Lebar, Marko Rupnik, Duško Lainšček, Miha Gradišek, Roman Jerala, Mojca Benčina, 2024, original scientific article Published in DiRROS: 09.09.2024; Views: 328; Downloads: 4009
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675. Precise design and construction of NiO-Ni heterostructures for active hydrogen evolution photocatalysisKamal Khaja Mohaideen, Rekha Narayan, Selvakannan Periasamy, Sašo Gyergyek, Stefan Popovic, Nejc Hodnik, Hsin-Chia Ho, Petar Djinović, Blaž Likozar, 2024, original scientific article Published in DiRROS: 09.09.2024; Views: 357; Downloads: 3957
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676. Environmental and economic impacts of hydroxyapatite mineralized wood : LCA and LCC analysisMatic Sitar, Manja Kitek Kuzman, Leon Oblak, Katarina Remic, 2024, original scientific article Abstract: Wood is considered a promising raw material for the circular bioeconomy and has the ability to store biogenic carbon, and this is one reason why we want to extend the service life of the wood. In order to consider the influence of durability in our study, we used two wood species with different lifespans. Beech (Fagus sylvatica L.) belongs to the group of very sensitive wood species, as the durability of the untreated wood is estimated to be around 5 years; meanwhile, pine (Pinus sylvestris L.) belongs to the group of moderately resistant wood species, where the durability of the untreated wood is estimated to be up to 15 years. While toxic chemicals are often used for wood preservation, hydroxyapatite offers an environmentally friendly solution for wood mineralization. This study presents life cycle assessment (LCA) and life cycle cost (LCC) analyses comparing a novel hydroxyapatite (HAp) mineralization method with a service life of 50 years to a non-mineralized reference alternative. LCA was based on EN ISO 14040 and EN ISO 14044, while LCC was adapted from the European Commission’s LCC tool for public procurement. The results of the LCA show that mineralized wood has a lower overall impact on the environment than surface-treated beech wood but a higher impact than surface-treated pine wood. Most impact categories were determined by electricity consumption with the exception of stratospheric ozone depletion, water consumption, and land use. Water consumption proved to be the category where the mineralization process was problematic due to water consumption during the leaching process. The LCC showed that mineralized wood is the most cost-effective solution for the exterior façade, as all costs, but especially investment costs, were lower. The differences in the LCA and LCC results are mainly due to the different lifetimes of the two alternatives. It can be concluded that if energy-intensive processes and chemicals are used in the production of the material, the extended lifetime must be sufficient to account for the additional impacts that occur during the production phase.
Keywords: environmental impacts, hydroxyapatite, life cycle assessment (LCA), life cycle cost analysis (LCC), wood mineralization
Published in DiRROS: 09.09.2024; Views: 323; Downloads: 2609
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677. Stabilization of river dredged sediments by means of alkali activation technologyKarmen Fifer Bizjak, Lea Žibret, Mojca Božič, Boštjan Gregorc, Vilma Ducman, 2024, original scientific article Abstract: Purpose
Alkali activation process has been applied to fresh river clay-rich sediments in order to increase their mechanical properties and make them suitable for soil stabilization.
Materials and methods
Dredged sediments were mixed with up to 30 mass percent (ma%) of fly ash (FA) or ladle slag (LS) and after curing for 3 days at 60 °C, the bending and compressive strength have been determined. The mixtures which exhibited the highest strengths were further optimized for being used in soil stabilization. For this purpose, the sediment was stabilized with 4 ma% of quicklime (QL) and after 1 h 30 ma% of FA with alkali activator was added and cured for 1, 7 and 28 days.
Results
The stabilized sediment has a significantely better geomechanical performance in comparison with the sediment alone. Stabilizing the dredged sediment using alkali activation technology provides high enough strengths to eventually make it suitable for anti-flood embankments.
Conclusions
The results confirmed the suitability of the investigated technology for soil stabilization.
Keywords: river sediment, alkali activated materials, ladle slag, fly ash, mechanical strength, soil stabilization
Published in DiRROS: 09.09.2024; Views: 353; Downloads: 4743
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680. UVB radiation as a potential selective factor favoring microcystin producing bloom forming cyanobacteriaYi Ding, Lirong Song, Bojan Sedmak, 2013, original scientific article Abstract: Due to the stratospheric ozone depletion, several organisms will become exposed to increased biologically active UVB (280-320 nm) radiation, not only at polar but also at temperate and tropical latitudes. Bloom forming cyanobacteria are exposed to UVB radiation on a mass scale, particularly during the surface bloom and scum formation that can persist for long periods of time. All buoyant species of cyanobacteria are at least periodically exposed to higher irradiation during their vertical migration to the surface that usually occurs several times a day. The aim of this study is to assess the influence on cyanobacteria of UVB radiation at realistic environmental intensities. The effects of two UVB intensities of 0.5 and 0.99 W/m2 in up to 0.5 cm water depth were studied in vitro on Microcystis aeruginosa strains, two microcystin producing and one non-producing. After UVB exposure their ability to proliferate was estimated by cell counting, while cell fitness and integrity were evaluated using light microscopy, autofluorescence and immunofluorescence. Gene damage was assessed by TUNEL assay and SYBR Green staining of the nucleoide area. We conclude that UVB exposure causes damage tothe genetic material, cytoskeletal elements, higher sedimentation rates and consequent cell death. In contrast to microcystin producers (PCC7806 and FACHB905), the microcystin non-producing strain PCC7005 is more susceptible tothe deleterious effects of radiation, with weak recovery ability. The ecological relevance of the results is discussed using data from eleven yearsʼcontinuous UVB radiation measurements within the area of Ljubljana city (Slovenia, Central Europe). Our results suggest that increased solar radiationin temperate latitudes can have its strongest effect during cyanobacterial bloom formation in spring and early summer. UVB radiation in this period may significantly influence strain composition of cyanobacterial blooms in favor of microcystin producers.
Keywords: microcystin, cyanobacteria
Published in DiRROS: 06.09.2024; Views: 305; Downloads: 125
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