1291. Achieving measurement comparability in mercury speciation analysis in seawater : Key requirements and best practicesIgor Živković, Lars-Eric Heimbürger-Boavida, Mariia V. Petrova, Aurélie Dufour, Ermira Begu, Milena Horvat, 2025, original scientific article Abstract: The comparability of measurement results is an important issue in contemporary mercury (Hg) speciation in seawater. Sampling campaigns must be properly designed to determine significant differences on spatial and temporal scales, considering two major parameters: the variability of expected data at a given sampling point/ transect and variability in the results due to the intrinsic properties of specific analytical methods, particularly the measurement uncertainty. This study assessed the required sample size, considering several aspects of data variability when determining total Hg, dissolved gaseous Hg, and methylated Hg species in seawater. The required sample sizes were calculated using (1) the measurement uncertainty of a single-laboratory measurement of analytical methods used; (2) performance of the laboratories in interlaboratory comparison exercises; and (3) natural variability in Hg species/fractions in a selected case study in the Central Adriatic Sea. It was shown that the measurement uncertainty of a particular method and interlaboratory variability among laboratories have significant influence on data interpretation in case natural variability of Hg fractions is relatively small, such as for example the open seawater depth profiles. In contrary, in areas with large natural variability of Hg con tractions, such as coastal and contaminated sites, their influence on data interpretation is negligible. The present paper introduces the importance of proper estimation of measurement uncertainty in international programs, such as GEOTRACES, where data comparability is of fundamental importance to assess temporal and spatial trends of Hg measurements in the marine environment
Published in DiRROS: 05.09.2025; Views: 335; Downloads: 87
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1297. In silico determination of novel SARS-CoV-2 envelope protein ion channel inhibitorsNina Kobe, Lennart Dreisewerd, Matic Pavlin, Polona Kogovšek, Črtomir Podlipnik, Uroš Grošelj, Miha Lukšič, 2025, original scientific article Abstract: The SARS-CoV-2 envelope protein (2-EPRO), a viroporin crucial for viral pathogenesis, is a promising target for antiviral drug development as it is highly conserved and functionally important. Although it is a promising therapeutic target for the treatment of COVID-19, it has often been overlooked in previous studies. In this study, a high-throughput virtual screening of nearly one billion compounds was performed, followed by rigorous filtering and re-docking. Eight best-scoring and chemically versatile lead candidates were identified. In molecular dynamics simulations, three of these ligands showed stable protein-ligand complexes occupying the 2-EPRO channel pore. Among these, ZINC001799167680 (L3) and ZINC001081252239 (L2) exhibited the strongest binding a˙inity, with key interactions at residues ASN15, THR11 and GLU8 identified by Molecular Mechanics Poisson-Boltzmann Surface Area analysis. All ligands were compared with the known inhibitor rimantadine and showed stronger binding to the protein. These in silico results highlight the potential of focusing on the 2-EPRO ion channel in the development of novel COVID-19 therapeutics and pave the way for further in vitro and in vivo studies.
Keywords: SARS-CoV-2 envelope protein, viroporin, ion channel, channel blockers, molecular dynamics simulations, free energy calculations, drug discovery
Published in DiRROS: 05.09.2025; Views: 362; Downloads: 147
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1298. Plasma treatment-promising tool for preparation of disposable monolithic columnsIta Junkar, Gregor Primc, Tanja Lukan, Matic Resnik, Janez Kovač, Andrijana Sever Škapin, Aleš Podgornik, Miran Mozetič, 2015, original scientific article Abstract: Atmospheric pressure plasma jet was employed to improve adhesion between polypropylene (PP) column wall and monolith used in chromatography. Different treatment conditions for modification of PP tube were used and the effects of treatment were analysed with X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). Modified surfaces had higher oxygen content and surface was covered with small grain like structures. To explore effects of modification on adhesion between PP tube and monolith tensile strength measurements were conducted. It was shown that appropriate treatment conditions significantly increased bonding strength. The improvement of adhesion was attributed to increased oxygen functional groups obtained from plasma.
Published in DiRROS: 05.09.2025; Views: 295; Downloads: 130
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1299. Integralni opis svetil in svetlobnih virovKatja Malovrh Rebec, Marta Klanjšek Gunde, Friderik Knez, 2015, original scientific article Abstract: Celostno vrednotenje svetilk in svetlobnih virov upošteva tako svetlobnotehnične kot tudi fotobiološke ter okoljske učinke, ki jih povzročajo tovrstni proizvodi. Fotobiološko vrednotenje počasi dobiva jasnejše oblike, saj so raziskave v zadnjem času ponudile ustrezne parametre za njihovo vrednotenje. Premiki pa se dogajajo tudi na okoljskem področju in gledetrajnostnosti rabe svetilk in virov. Okoljske deklaracije produktov (EPD - Environmental Product Declaration), ki opisujejo vplive proizvodov na okolje, so namenjene predvsem komunikaciji med podjetji (B2B - business-to-business). Skladne so s standardom ISO 14025. Pri razsvetljavi se srečamo z ožjo temo, in sicer trajnostnostjo gradnje in gradbenih proizvodov. Pri tem se ne sprašujemo le, kakšna je raba energije v času uporabe proizvoda, temveč tudi, koliko energije je v proizvod vgrajene v času nastajanja ter kaj se zgodi, ko proizvod zavržemo. Deklaracija EPD torej temelji na oceni celotnega življenjskega cikla ali LCA-analizi (Life Cycle Assessment). Pripravili smo podrobnejšo analizo in interpretacijo 5 primerov EPD-jev svetil različnih proizvajalcev. V nekatera svetila so vgrajeni LED-viri (Philips, Zumtobel), v druga pa kompaktne fluorescenčne sijalke CFL (Thorn) ali metalhalogenidni viri (We-Ef Leuchten), obravnavamo tudi primer za predstikalno napravo (Tridonic). Primerljivost rezultatov ostaja velik izziv.
Keywords: svetlobna tehnika, svetila, tehnične zahteve, okoljske zahteve
Published in DiRROS: 05.09.2025; Views: 282; Downloads: 117
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1300. Mechanical and microstructural characterization of geopolymer synthesized from low calcium fly ashSabina Dolenec, Vilma Ducman, 2015, original scientific article Abstract: This study deals with the mechanical and microstructural characterization of geopolymers synthesized from locally available fly ash. A low calcium fly ash was activated using a sodium silicate solution. Samples were characterized by means of flexural and compressive tests, Fourier Transform Infrared (FTIR) spectroscopy, X-ray powder diffraction (XRD), and scanning electron microscopy(SEM). Porosity and pore size distributions were identified using mercury intrusion porosimetry and gas sorption. The compressive strength of the produced geopolymers, which is in the range of 1.6 to 53.3 N/mm2, is strongly related to the water content as well as SiO2/Na2O mass ratio of an alkali activator. The compressive strength significantly increased with decreases in the water content and increased silicon concentration used for the synthesis of geopolymers.
Keywords: geopolymers, fly ash, microstructure, mechanical properties
Published in DiRROS: 05.09.2025; Views: 406; Downloads: 193
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