1. Comparison of pulmonary and aortic root and cusp dimensions in normal adults using computed tomography : potential implications for Ross procedure planningMatija Jelenc, Blaž Jelenc, Sara Habjan, Karen B. Abeln, Peter Fries, Hector I. Michelena, Hans Joachim Schäfers, 2024, izvirni znanstveni članek Povzetek: Objectives: The Ross procedure is currently receiving renewed interest. Its function and durability depend on preservation of pulmonary valve anatomy; limited data exist on normal pulmonary valve geometry. The objective was to compare aortic and pulmonary root and cusp dimensions in adults with normal tricuspid aortic and pulmonary valves. Methods: We reviewed 507 coronary computed tomography studies, selecting those with adequate visibility of both pulmonary and aortic roots for further analysis. Diastolic aortic and pulmonary root and cusp dimensions were measured. Root dimensions at different phases of the cardiac cycle were measured in 3 patients. Results: We analysed studies of 50 patients with the mean age of 54 years [standard deviation (SD): 16]. In end-diastole, pulmonary root had a smaller sinutubular to basal ring ratio than the aortic root [0.82 (SD: 0.09) vs 1.14 (SD: 0.12), P<0.001]. Aortic and pulmonary cusps had similar dimensions; however, pulmonary cusp effective height was lower [5.9 mm (SD: 1.6) vs 8.4 mm (SD: 1.2), P<0.001]. Pulmonary basal ring perimeter was largest at end-diastole and smallest at end-systole, with the relative difference of 23.5% (SD: 2.7). Conclusions: The pulmonary root has a similar cusp size compared to the aortic root, but a different shape, resulting in a lower pulmonary cusp effective height. The perimeter of the pulmonary basal ring changes during the cardiac cycle. These findings suggest that stabilizing the autograft to normal aortic, rather than pulmonary, root dimensions should result in normal autograft cusp configuration. Computed tomography angiography could become a tool for personalized planning of the Ross procedure.
Ključne besede: computed tomography angiography, pulmonary valve anatomy, ross procedure, aortic valve anatomy, cardiac cycle
Objavljeno v DiRROS: 26.11.2025; Ogledov: 128; Prenosov: 74
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2. 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, izvirni znanstveni članek Povzetek: 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.
Ključne besede: type IIA DNA topoisomerase, T-segment, C-gate, catalytic cycle, molecular dynamics
Objavljeno v DiRROS: 19.09.2025; Ogledov: 340; Prenosov: 154
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3. Menstrual symptoms in division I female athletes : a prospective observational studyJennifer Bunn, Gabrielle Marchelli, Hannah Humphries, 2025, izvirni znanstveni članek Povzetek: Purpose: To quantify the frequency of menstrual cycle (MC) symptoms experienced by Division I female lacrosse athletes and to discover if the symptoms were different among those who were taking a hormone contraceptive (HC) compared to those who were not (non-HC). Methods: As part of a daily wellness survey, athletes (non-HC = 10, HC = 11) were asked if they were menstruating. If they were, they were asked to identify any symptoms they were experiencing. The symptoms were recorded for each day of menstruation during their four-month competitive season. Reported symptoms were categorized as frequently, sometimes, rarely, or never. The frequencies of symptoms were tabulated in total and per cycle for each group. Results: The most frequently reported symptom was cramps with 90.4% of athletes reporting experiencing it at least once. Headaches (66%), back pain, and skin problems (57% each) were also frequently reported. HC users (0.7 ± 1.4 times/cycle) reported mood swings more frequently than non-HC users (0.03 ± 0.08, p = 0.029), but there were no other group differences for symptoms. Conclusions: Tracking symptoms associated with MC can help athletes and coach-es be aware of patterns and incorporate methods for mitigating or alleviating the symp-toms. Symptom tracking can also help athletes mentally prepare for the effects of their C on training and performance. More research is needed before recommending HC use as a management strategy for menstrual symptoms.
Ključne besede: menstrual cycle, team sport, hormone contraceptive
Objavljeno v DiRROS: 09.09.2025; Ogledov: 215; Prenosov: 101
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4. Research on reflection cracking characteristics of warm-mix recycled asphalt mortar under the effect of freeze-thaw cyclesJian Gao, Zhiqiang Liu, Chao Li, Lan Wang, Yudong Ma, 2025, izvirni znanstveni članek Ključne besede: warm-mix recycled asphalt mortar, freeze-thaw cycle, reflection cracking characteristics, digital image correlation technology, cracking damage factor
Objavljeno v DiRROS: 20.08.2025; Ogledov: 396; Prenosov: 190
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5. Impacts of high PV penetration on Slovenia’s electricity grid : Energy Modeling and Life Cycle AssessmentJože Dimnik, Jelena Topić, Ante Čikić, Simon Muhič, 2024, izvirni znanstveni članek Povzetek: The complexities of high PV penetration in the electricity grid in Slovenia based on targets proposed in national energy and climate plan were explored. Scenarios modeled an increase in installation power from 1800 MW in 2030 to 8000 MW in 2050. They were analyzed using energy modeling and life cycle assessment to assess the technical and environmental aspects of high PV grid penetration. The results showed that the increase in PV production from 2200 GWh (2030) to 11,090 GWh (2050) showed an unfavorable course of excess electricity in the system, resulting in the need for short-term and long-term storage strategies and exports of electricity. LCA analysis showed that penetration of a high share of PV results in a decrease in the impact category of global warming, which is higher in 2050 green scenarios that phase out coal and lignite electricity sources (80.5% decrease) compared to the 2020 baseline scenario. The increase in mineral resource scarcity can be observed with an increase in PV share when comparing the 2030 (50%) and 2050 (150%) BAU scenarios with the baseline scenario (2020). Factors such as environmental impacts, technical challenges, and the impact on the grid must be considered when implementing a decarbonization strategy.
Ključne besede: photovoltaic electricity production, sustainable energy system, life cycle assessment, Slovenia, electricity production
Objavljeno v DiRROS: 15.07.2025; Ogledov: 444; Prenosov: 265
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6. Environmental and littering impacts of disposable cups made of polypropylene and polylactic acid in GermanyChristina Galafton, Vaibhav Budhiraja, Sarah Stevens, Branka Mušič, Daniel de Almeida Magalhães, 2025, izvirni znanstveni članek Povzetek: As a result of improper management, plastics such as drinking cups are accumulating in environmental compartments worldwide, impacting biodiversity and ecosystem services. The goal of this study is to analyze and compare potential environmental impacts of disposable cups made of Polypropylene and Polylactic acid with the help of a cradle-to-grave life cycle assessment, including impacts related to the littering of these cups. Plastic pollution impacts are calculated based on the products' persistence in the environment, comparing the results of our own experiment to literature data. As an indication of the possible adverse health effects of Polypropylene and Polylactic acid, a toxicity test of the chemical mixtures migrating from the cups is conducted. Overall, the cups made of Polypropylene show lower environmental impacts compared to those made of Polylactic acid when the experimentally determined degradation rates are used. Nevertheless, regarding toxicity of the chemical migrates, the cup made of Polylactic acid performs better than the one made of Polypropylene. Considering all impact categories, there is no overall improvement in environmental impacts of producing the cup from Polylactic acid instead of Polypropylene. Our results indicate the importance of using degradation data measured specifically for the assessed product. Methodologically, we demonstrate a possible integration of life cycle assessment and safe-and-sustainable-by-design scoring. Further development of the plastic pollution impact category is needed to integrate effects on the terrestrial environment.
Ključne besede: degradation, accelerated weathering, product environmental footprint, life cycle assessment, plastic pollution, toxicity
Objavljeno v DiRROS: 27.05.2025; Ogledov: 784; Prenosov: 460
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7. Environmental footprint of external thermal insulation composite systems with different insulation typesTajda Potrč Obrecht, Katja Malovrh Rebec, Friderik Knez, Roman Kunič, Andraž Legat, 2016, objavljeni znanstveni prispevek na konferenci Povzetek: In terms of upcoming energy directive for Nearly Zero Energy Houses (nZEB), we are very much focused on building skin and its properties. Not only thermal characteristics and design, but also durability and environmental aspects should play a role, when deciding on which system will be implemented. External Thermal Insulation Composite Systems or ETICS are generally made of adhesive, insulation, render with mesh reinforcement, primer and finish coat. In the following case study we have presented a life cycle assessment (LCA) study of three ETICS with different types of insulation: expanded polystyrene (EPS), mineral wool and wood fiber board insulation. The study complies to the standard EN 15804:2012. It was conducted in the program Gabi using the Gabi Professional 2012 Database. The scope of the study is covering the production phase (raw material supply, transport to the factory, manufacturing). We have compared the functional unit of 1 sqm of the ETICS system with U-value 0.27 W/m2K taking into account different environmental impact categories. In the calculation the characterization factors proposed by Centre of Environmental Science (CML) at Leiden University were used. The comparison of ETICS shows the important impact of the insulation type used. Also there are some differences in the amount of other ETICS components applied, since changing the type of insulation affects the environmental footprint of the ETICS.
Ključne besede: ETICS, life cycle assessment, nearly zero energy house, insulition types
Objavljeno v DiRROS: 04.03.2025; Ogledov: 704; Prenosov: 329
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8. Initial glutathione depletion during short-term bed rest : pinpointing synthesis and degradation checkpoints in the γ-glutamyl cycleFilippo Giorgio Di Girolamo, Filippo Mearelli, Mariella Sturma, Nicola Fiotti, Kaja Teraž, Alja Ivetac, Alessio Nunnari, Pierandrea Vinci, Boštjan Šimunič, Rado Pišot, Gianni Biolo, 2024, izvirni znanstveni članek Povzetek: Hypokinesia triggers oxidative stress and accelerates the turnover of the glutathione system via the γ-glutamyl cycle. Our study aimed to identify the regulatory checkpoints controlling intracellular glutathione levels. We measured the intermediate substrates of the γ-glutamyl cycle in erythrocytes from 19 healthy young male volunteers before and during a 10-day experimental bed rest. Additionally, we tracked changes in glutathione levels and specific metabolite ratios up to 21 days of bed rest. Using gas chromatography-mass spectrometry and the internal standard technique, we observed a 9 ± 9% decrease in glutathione levels during the first 5 days of bed rest, followed by an 11 ± 9% increase from the 5th to the 10th day, nearly returning to baseline ambulatory levels. The cysteinyl-glycine-to-glutathione ratio, reflecting γ-glutamyl cyclotransferase activity (a key enzyme in glutathione breakdown), rose by 14 ± 22% in the first 5 days and then fell by 10 ± 14% over the subsequent 5 days, again approaching baseline levels. Additionally, the γ-glutamyl cysteine-to-cysteine ratio, indicative of γ-glutamyl cysteine synthetase activity (crucial for glutathione synthesis), increased by 12 ± 30% on day 5 and by 29 ± 41% on day 10 of bed rest. The results observed on day 21 of bed rest confirm those seen on day 10. By calculating the ratio of product concentration to precursor concentration, we assessed the efficiency of these key enzymes in glutathione turnover. These results were corroborated by directly measuring glutathione synthesis and degradation rates in vivo using stable isotope techniques. Our findings reveal significant changes in glutathione kinetics during the initial days of bed rest and identify potential therapeutic targets for maintaining glutathione levels.
Ključne besede: antioxidant, muscle unloading, glutathion turnover, γ-glutamyl cycle, gamma-glutamyl cycle
Objavljeno v DiRROS: 21.11.2024; Ogledov: 836; Prenosov: 1585
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9. Environmental and economic impacts of hydroxyapatite mineralized wood : LCA and LCC analysisMatic Sitar, Manja Kitek Kuzman, Leon Oblak, Katarina Remic, 2024, izvirni znanstveni članek Povzetek: 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.
Ključne besede: environmental impacts, hydroxyapatite, life cycle assessment (LCA), life cycle cost analysis (LCC), wood mineralization
Objavljeno v DiRROS: 09.09.2024; Ogledov: 953; Prenosov: 3021
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10. Environmental life cycle assessment of railway bridge materials using UHPFRCKarmen Fifer Bizjak, Aljoša Šajna, Katja Slanc, Friderik Knez, 2016, izvirni znanstveni članek Povzetek: The railway infrastructure is a very important component of the world’s total transportation network. Investment in its construction and maintenance is significant on a global scale. Previously published life cycle assessment (LCA) studies performed on road and rail systems very seldom included infrastructures in detail, mainly choosing to focus on vehicle manufacturing and fuel consumption. This article presents results from an environmental study for railway steel bridge materials for the demonstration case of the Buna Bridge in Croatia. The goal of these analyses was to compare two different types of remediation works for railway bridges with different materials and construction types. In the first part, the environmental impact of the classical concrete bridge construction was calculated, whereas in the second one, an alternative new solution, namely, the strengthening of the old steel bridge with ultra-high-performance fibre-reinforced concrete (UHPFRC) deck, was studied. The results of the LCA show that the new solution with UHPFRC deck gives much better environmental performance. Up to now, results of LCA of railway open lines, railway bridges and tunnels have been published, but detailed analyses of the new solution with UHPFRC deck above the old bridge have not previously been performed.
Ključne besede: railway, materials, ife cycle assessment, bridge, environmental
Objavljeno v DiRROS: 23.08.2024; Ogledov: 880; Prenosov: 659
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