1. Investigations of chemical element distributions in soil, North Macedonia—a reviewTrajče Stafilov, Robert Šajn, Jasminka Alijagić, 2024, izvirni znanstveni članek Povzetek: This review article considers the following aspects: naturally distributed chemical elements and their enrichments, and the increased occurrence of PTEs due to anthropogenic and urban activities, as well as due to the geochemical uniqueness of certain geochemical landscapes, depending on the lithological environment. The review article is the result of many years of successful cooperation between the Geological Survey of Slovenia and the Faculty of Natural Sciences in Skopje, Ss. Cyril and Methodius University in Skopje, as well as several other institutions from North Macedonia, Russia and Romania but, also, through the voluntary and enthusiastic work of Prof. Trajče Stafilov’s PhD and Master’s students. To create the Geochemical Atlas, the territory of North Macedonia was covered with 995 sampling locations, but 16 separate areas with soil contamination were additionally sampled. The total sum of all collected soil samples was 3983 from 2449 different sampling sites in the period from 2006 to 2017. The analyses were performed at the Institute of Chemistry, Faculty of Natural Sciences in Skopje, at the Ss. Cyril and Methodius University in Skopje, North Macedonia, at the Research Institute for Analytical Instrumentation (ICIA), Cluj-Napoca, Romania, at the Joint Institute for Nuclear Research in Dubna, Moscow Region, Russia, and at Acme Labs in Vancouver, Canada. The sum of all analysed soil samples in all four mentioned laboratories was 7991 from 2006 to 2017. Using advanced mathematical methods such as multivariate statistical methods (HCA, FA, PCA) and artificial neural networks–multilayer perceptron (ANN-MP), predictions were made about the concentrations of potentially toxic elements (PTEs) and their distribution in real space. In less than two decades (2007–2023) of fruitful collaboration, a large number of scientific works have been published: 188 scientific publications, 8 geochemical atlases and 23 chapters in monographs.
Ključne besede: chemical elements, distribution, pollution, soil, North Macedonia
Objavljeno v DiRROS: 25.03.2024; Ogledov: 134; Prenosov: 88
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2. Multivariate statistical methods in determining the spatial distribution of chemical elements in soil from the Mavrovo-Rostuše region, North MacedoniaTrajče Stafilov, Robert Šajn, Kristina Petrovska, 2023, izvirni znanstveni članek Povzetek: In this work, the contents and spatial distributions of 19 elements (Ag, Al, B, Ba, Ca, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, P, Pb, Sr, V, Zn) in the soil of the western part of North Macedonia (Mavrovo-Rostuše region) are presented. For this purpose, a total of 66 soil samples were collected from 33 locations (33 samples of topsoil, 0-5 cm, and 33 samples of subsoil, 20-30 cm). All samples were analysed by inductively coupled plasma - atomic emission spectrometry (ICP-AES) after complete digestion with four acids (HNO3, HF, HClO4 and HCl). The obtained results were statistically evaluated and spatial distribution maps for all analysed elements were also prepared. Factor analysis was performed to reduce the number of data used and new synthetic variables (factors) were identified. Through the application of factor analysis, three geochemical associations were identified: Factor 1 (Zn, K, Cu, Fe, and Li), Factor 2 (Cr, Ni, and Mg) and Factor 3 (Ca and Al). From the obtained data and the maps of spatial distribution, it could be concluded that the distribution of the analysed elements is related to the lithology of the region. Thus, it was found that the higher content of elements of Factor 1 occurs in the eastern and southern part of the study area (middle and lower reaches of the Radika River and along the Mala River), where Mesozoic and Paleozoic carbonates as well as Paleozoic shales and Paleogene flysch prevail. Factor 2 (Cr, Ni and Mg) also represents a lithogenic association. The highest contents of the elements in both soil layers were found in the areas where Paleozoic sandstones and shales (village of Lazaropole and the area around the Mavrovo Lake) and Paleogene flysch (Rostuše village) predominate. Factor 3 (Ca and Al) also represents lithogenic association of elements. The highest content of these elements was found in the northwestern part of the study area (village of Žirovnica and along the Berička River) and in the northeastern region above the village of Brodec where Mesozoic carbonates and Paleogene flysch dominate.
Ključne besede: soil, heavy metals, spatial distribution, Mavrovo-Rostuše region, North Macedonia
Objavljeno v DiRROS: 04.01.2024; Ogledov: 207; Prenosov: 51
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3. Distribution of chemical elements in surface waters from the Strumica River Basin, North MacedoniaKaterina Trajanova, Robert Šajn, Trajče Stafilov, 2023, izvirni znanstveni članek Povzetek: In this work, the distribution of chemical elements in samples of surface water from the Strumica River Basin, North Macedonia, was studied. The water samples were collected from a total of twelve sites. In addition to the Strumica River, samples were collected from its tributaries: Bansko, Dabile, Turija, Vodoča, Radoviška, and Injevska. The determination of the concentration of 21 elements (Ag, Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, Sr, V, and Zn) was performed by inductively coupled plasma - atomic emission spectrometry (ICP-AES). All detailed information on the studied items was statistically processed using Stat Soft, 11.0 software. Using the obtained data on the concentration of the studied elements, descriptive statistical analysis of the values for the concentration of the elements was performed. A map of spatial distribution was obtained for each element. The obtained results show that the concentrations of the studied elements in the surface water samples are relatively low and the distribution of most of the elements follows the lithology of the study area.
Ključne besede: rivers, surface water, heavy metals, Strumica River Basin, North Macedonia
Objavljeno v DiRROS: 20.07.2023; Ogledov: 342; Prenosov: 110
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4. Next-generation sequencing to characterize pyrazinamide resistance in Mycobacterium tuberculosis isolates from two Balkan countriesEva Sodja, Simon Koren, Nataša Toplak, Sara Truden, Marija Žolnir-Dovč, 2021, izvirni znanstveni članek Povzetek: Objectives. Next-generation sequencing (NGS) provide a comprehensive analysis of the genetic alterations that are most commonly linked with pyrazinamide (PZA) resistance. There are no studies reporting molecular background of PZA resistance in TB isolates from Balkan Peninsula. We aimed to examine the feasibility of full-length analysis of a gene linked with PZA resistance, pncA, using Ion Torrent technology in comparison to phenotypic BACTEC MGIT 960 DST in clinical TB isolates from two countries of the Balkan Peninsula. Methods. Between 1996 and 2017, we retrospectively selected 61 TB isolates. To identify gene variants related to drug resistance in genomic DNA extracted from TB isolates, AmpliSeq libraries were generated automatically using the AmpliSeq™ Kit for Chef DL8 and the Ion AmpliSeq TB Research Panel. Result.s Of all 61 TB isolates included, 56 TB were phenotypically resistant to any antibiotic. Among them, 38/56 (67.9%) TB isolates were phenotypically resistant to pyrazinamide and pncA mutations were detected in 33/38 cases (86.8%). A mutation in the pncA promoter region was the most prevalent genetic alteration, detected in eight TB isolates. Comparison of NGS to conventional BACTEC MGIT 960 DST revealed very strong agreement (90.2%) between the two methods in identifying PZA resistance, with high sensitivity (89.5%) and specificity (95.7%) for NGS. Conclusions. Detection of PZA resistance using NGS seems to be a valuable tool for surveillance of TB drug resistance also in the Balkan Peninsula, with great potential to provide useful information at least one weak earlier than is possible with phenotypic DST.
Ključne besede: tuberculosis, Mycobacterium tuberculosis, high-throughput nucleotide sequencing, pyrazinamide, microbial sensitivity tests, next-generation sequencing, drug susceptibility testing, Slovenia, Republic of North Macedonia
Objavljeno v DiRROS: 10.01.2022; Ogledov: 906; Prenosov: 557
Celotno besedilo (1,53 MB)
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