1. Estimating exposure to extremely low frequency magnetic fields near high-voltage power lines and assessment of possible increased cancer risk among Slovenian children and adolescentsTina Žagar, Blaž Valič, Tadej Kotnik, Sara Korat, Sonja Tomšič, Vesna Zadnik, Peter Gajšek, 2023, izvirni znanstveni članek Ključne besede: exposure assessment, childhood cancer, extremely low frequency magnetic fields, modelling, high voltage power lines
Objavljeno v DiRROS: 25.07.2024; Ogledov: 121; Prenosov: 555
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2. Synergetic boost of functional properties near critical end points in antiferroelectric systemsVida Jurečič, Lovro Fulanović, Jurij Koruza, Vid Bobnar, Nikola Novak, 2023, izvirni znanstveni članek Povzetek: The increase of the dielectric permittivity with an electric field and enhanced energy storage properties make antiferroelectrics very attractive for high-power electronic applications needed in emerging green energy technologies and neuromorphic computing platforms. Their exceptional functional properties are closely related to the electric field-induced antiferroelectric↔ferroelectric phase transition, which can be driven toward a critical end point by manipulation with an external electric field. The critical fluctuation of physical properties at the critical end point in ferroelectrics is a promising approach to improve their functional properties. Here, we demonstrate the existence of two critical end points in antiferroelectric ceramics with a ferroelectric-antiferroelectric-paraelectric phase sequence, using the model system Pb 0.99 Nb 0.02 [ ( Zr 0.57 Sn 0.43 ) 0.92 Ti 0.08 ] 0.98 O 3 . The critical fluctuation of the dielectric permittivity in the proximity of the antiferroelectric-to-paraelectric critical end point is responsible for the strong enhancement of the dielectric tunability (by a factor of > 2 ) measured at ≈ 395 K. The enhancement of the energy storage density at ≈ 370 K is related to the proximity of the ferroelectric-to-antiferroelectric critical end point. These findings open possibilities for material design and pave the way for the next generation of high-energy storage materials.
Ključne besede: electronic applications, high-power electronic, green energy, electric field
Objavljeno v DiRROS: 10.07.2024; Ogledov: 161; Prenosov: 111
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3. Genotoxicity and heating performance of VxFe3-xO4 nanoparticles in health applicationsBeatriz Sanz-Sagué, Amaia Sáenz-Hernández, Bojana Žegura, Alja Štern, Katja Kološa, Iza Rozman, 2024, izvirni znanstveni članek Povzetek: The applications of magnetic nanoparticles (MNPs) as biocatalysts in different biomedical areas have been evolved very recently. One of the main challenges in this field is to design affective MNPs surfaces with catalytically active atomic centres, while producing minimal toxicological side effects on the hosting cell or tissues. MNPs of vanadium spinel ferrite (VFe2O4) are a promising material for mimicking the action of natural enzymes in degrading harmful substrates due to the presence of active V5+ centres. However, the toxicity of this material has not been yet studied in detail enough to grant biomedical safety. In this work, we have extensively measured the structural, compositional, and magnetic properties of a series of VxFe3-xO4 spinel ferrite MNPs to assess the surface composition and oxidation state of V atoms, and also performed systematic and extensive in vitro cytotoxicity and genotoxicity testing required to assess their safety in potential clinical applications. We could establish the presence of V5+ at the particle surface even in water-based colloidal samples at pH 7, as well as different amounts of V2+ and V3+ substitution at the A and B sites of the spinel structure. All samples showed large heating efficiency with Specific Loss Power values up to 400 W/g (H0 = 30 kA/m; f = 700 kHz). Samples analysed for safety in human hepatocellular carcinoma (HepG2) cell line with up to 24h of exposure showed that these MNPs did not induce major genomic abnormalities such as micronuclei, nuclear buds, or nucleoplasmic bridges (MNIs, NBUDs, and NPBs), nor did they cause DNA double-strand breaks (DSBs) or aneugenic effects—types of damage considered most harmful to cellular genetic material. The present study is an essential step towards the use of these type of nanomaterials in any biomedical or clinical application.
Ključne besede: magnetic nanoparticles, vanadium ferrite, cytotoxicity, genotoxicity, specific power absorption, cell viability
Objavljeno v DiRROS: 23.05.2024; Ogledov: 253; Prenosov: 270
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4. Lower-limb muscle contractile properties, explosive power and the subjective response of elite soccer players to the Covid-19 lockdownArmin Paravlić, Boštjan Šimunič, Saša Pišot, Matej Kleva, Kaja Teraž, Matjaž Vogrin, Uroš Marušič, Rado Pišot, 2022, izvirni znanstveni članek Povzetek: The present study examined the effects of the lockdown period on basic anthropometric measures, countermovement jumping performance, skeletal muscle contractile properties derived from tensiomyography (TMG), injury incidence, and self-assessed general well-being in elite soccer players. A total of 266 players were assessed before (PRE) and 32 players were reassessed 11 days after (POST) the COVID-19 period. Significant changes in the TMG parameters were observed POST compared to PRE: contraction time (Tc) increased from 6% to 50% in vastus lateralis [VL] (p = 0.009) and biceps femoris [BF] (p < 0.001), respectively; whereas radial displacement (Dm) increased for 19% in BF (p = 0.036) and 17% in VL (p < 0.001), respectively. Jumping performance remained unchanged from PRE to POST In addition, athletes rated the lockdown period as a positive event and felt psychologically better during the lockdown, primarily because they spent more time with family members and friends. Although there were no differences in any of the variables describing lower limb muscle power following the two-month lockdown, the altered contractile properties of the assessed muscles suggest suboptimal conditioning of the football players.
Ključne besede: football, male football, power, explosive power, tensiomyography, coronavirus, covid-19, pandemics, lockdown
Objavljeno v DiRROS: 06.01.2022; Ogledov: 970; Prenosov: 592
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