1621. Sinonasal inverted papilloma associated with squamous cell carcinomaJasna But-Hadžić, Klemen Jenko, Mario Poljak, Boštjan Kocjan, Nina Gale, Primož Strojan, 2011, izvirni znanstveni članek Ključne besede: rak (medicina), papiloma virusi, nosna votlina, karcinom, zdravljenje, radioterapija Objavljeno v DiRROS: 18.03.2024; Ogledov: 345; Prenosov: 97
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1623. Comparison of elemental composition of surface and subsurface soils on national level and identification of potential natural and anthropogenic processes influencing its compositionEmil Pučko, Gorazd Žibret, Klemen Teran, 2024, izvirni znanstveni članek Povzetek: The elemental composition of soils is governed by geogenic processes and anthropogenic activities. A comprehensive soil study was conducted on a national level, in which the elemental composition of soils from two different layers was compared with the intention to differentiate between natural and anthropogenic sources of elemental enrichments. Topsoil (0–5 cm) and subsoil (20–30 cm) samples were collected from 249 different locations on a national scale (Slovenia). Elemental composition for 55 major, minor, and trace elements (ICP-MS, aqua regia digestion) was determined on the fraction <0.063 mm. By calculating the enrichment ratios in different lithological units, it was determined that levels of Ti are higher in soils overlying metamorphic and igneous rocks, Zr and Ca are more abundant over carbonates, while levels of Ni are higher in soils overlying marlstones. Elevated levels of Hg were detected in subsoils in the historical Hg mining area in Idrija, which indicates the presence of nearby orebodies as a potential source for the geochemical anomaly. Spatial distribution of elements showed that higher levels of Pb, Zn, Cu, and Hg were detected in topsoils of urban areas, indicating that anthropogenic sources could be the potential cause of soil contamination. Pb, Zn, Cu, and Hg levels were up to four times higher in topsoils compared to subsoils sampled at historical mining areas (e.g., Mežica, Idrija, Litija), which shows that historical mining left a significant environmental impact. Although mining and smelting activities ended a few decades ago, soils in some areas are still heavily enriched with various metals. Some other potential anthropogenic sources of elements were identified, such as farming and ironworks. Based on the results of this study, we can conclude that by comparing elemental compositions of soils from different layers, we can recognise the origin of elemental enrichments. Ključne besede: smelting, mining, urbanisation, traffic, ironworks, weathering Objavljeno v DiRROS: 18.03.2024; Ogledov: 280; Prenosov: 104
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1627. A method for computing the edge-Hosoya polynomial with application to phenylenesMartin Knor, Niko Tratnik, 2023, izvirni znanstveni članek Povzetek: The edge-Hosoya polynomial of a graph is the edge version of the famous Hosoya polynomial. Therefore, the edge-Hosoya polynomial counts the number of (unordered) pairs of edges at distance $k \ge 0$ in a given graph. It is well known that this polynomial is closely related to the edge-Wiener index and the edge-hyper-Wiener index. As the main result of this paper, we greatly generalize an earlier result by providing a method for calculating the edge-Hosoya polynomial of a graph $G$ which is obtained by identifying two edges of connected bipartite graphs $G_1$ and $G_2$. To show how the main theorem can be used, we apply it to phenylene chains. In particular, we present the recurrence relations and a linear time algorithm for calculating the edge-Hosoya polynomial of any phenylene chain. As a consequence, closed formula for the edge-Hosoya polynomial of linear phenylene chains is derived. Ključne besede: edge-Hosoya polynomial, graphs, phenylenes Objavljeno v DiRROS: 18.03.2024; Ogledov: 483; Prenosov: 383
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1628. How to compute the M-polynomial of (chemical) graphsEmeric Deutsch, Sandi Klavžar, Gašper Domen Romih, 2023, izvirni znanstveni članek Povzetek: Let $G$ be a graph and let $m_{i,j}(G)$, $i,j\ge 1$, be the number of edges $uv$ of ▫$G$▫ such that $\{d_v(G), d_u(G)\} = \{i,j\}$. The M-polynomial of $G$ is $M(G;x,y) = \sum_{i\le j} m_{i,j}(G)x^iy^j$. A general method for calculating the M-polynomials for arbitrary graph families is presented. The method is further developed for the case where the vertices of a graph have degrees 2 and $p$, where $p\ge 3$, and further for such planar graphs. The method is illustrated on families of chemical graphs. Ključne besede: M-polynomial, chemical graph, planar graph Objavljeno v DiRROS: 18.03.2024; Ogledov: 299; Prenosov: 87
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1629. Qualitative analysis of the minimal Higgins model of glycolysisBrigita Ferčec, Matej Mencinger, Tatjana Petek, Orhan Ozgur Aybar, Ilknur Kusbeyzi Aybar, 2023, izvirni znanstveni članek Povzetek: Glycolysis, one of the leading metabolic pathways, involves many
different periodic oscillations emerging at positive steady states of
the biochemical models describing this essential process. One of
the models employing the molecular diffusion of intermediates is
the Higgins biochemical model to explain sustained oscillations. In
this paper, we investigate the center-focus problem for the minimal
Higgins model for general values of the model parameters with the
help of computational algebra. We demonstrate that the model
always has a stable focus point by finding a general form of the first
Lyapunov number. Then, varying two of the model parameters, we
obtain the first three coefficients of the period function for the stable focus point of the model and prove that the singular point is actually a bi-weak monodromic equilibrium point of type $[1, 2]$. Additionally, we prove that there are two (small) intervals for a chosen parameter $a > 0$ for which one critical period bifurcates from this singular point after small perturbations. Ključne besede: biological processes, biochemical models, glycolysis Objavljeno v DiRROS: 18.03.2024; Ogledov: 291; Prenosov: 123
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