Faculty of Natural Sciences and Mathematics

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Structural and optical properties of mixed phase WO3 – ZnWO4 films synthesized from thermally oxidized metallic Zn–W films
(Elsevier BV, 2026-06)
Jovanovski, Stefan
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Popović, Maja
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Novaković, Mirjana
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Tungsten-bearing compounds have attracted significant interest in recent years, especially in thin films or nano powder form, due to their photocatalytic activity stemming from their wide band gap semiconductor properties. This study presents the synthesis of mixed phase WO3–ZnWO4 films synthesized by thermal oxidation of co-sputtered metallic Zn–W films. From XRD analysis it appeared that annealing at 600 °C leads to the formation of the monoclinic Zn-tungstate phase within the WO3 matrix with crystallite size about 50 nm for both phases. The XPS analysis of the O1s peak showed mixed phase compound of WO3 matrix with about 13 at.% of ZnWO4. Raman and infrared spectroscopy further characterize the structural features, revealing the WO6 octahedral unit as main building block in the structure. The optical band gap of the annealed film was found to be 3.34 eV, indicating a wide gap semiconductor. The films displayed a UV induced Photoluminescence with broad PL spectra with emission maximum at about 2.48 eV. The study demonstrates that co-sputtering and annealing at 600 °C approach is effective for synthesizing of tungstate phase ZnWO4 within WO3 matrix.
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Diagnostic reference levels (DRLs) in digital mammography in the European context – a systematic review
(Walter de Gruyter GmbH, 2025-08-28)
Arifi, Mirjeta Mediji
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Ristova, Mimoza M.
This systematic review examines the establishment of Diagnostic Reference Levels (DRLs) in digital mammography across 18 European countries, based on studies from 2005-2025. A total of 353 articles were identified through the comprehensive search of academic networks: Google Scholar, PubMed, Research Gate, Academia. Only 18 peer-reviewed studies met inclusion criteria – reporting Mean Glandular Dose (MGD)-based DRLs from Finland to Malta. Eight studies used patient data, four used phantom measurements, and six used both. To overcome the challenging comparison of the variety of reported parameters, we undertook some data harmonisation procedures, focusing on a common Compressed Breast Thickness (CBT) range of 50-59 mm. The DRLs varied notably by country, with 75th percentile MGDs ranging from 1.1 to 2.6 mGy and 95th percentile from 1.6 to 2.9 mGy, averaging to 1.44 mGy, which is lower than the achievable European level (2 mGy). The harmonisation approach enabled the derivation of a comparable dataset of average MGDs, facilitating cross-country comparisons and insights into radiation dose optimisation in digital mammography across Europe.
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Preparation of CuWO4 films by thermal annealing of simultaneously RF/DC magnetron co-sputtered Cu–W films
(Elsevier BV, 2025-10)
Jovanovski, Stefan
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Popović, Maja
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Novaković, Mirjana
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Jugović, Dragana
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Gloginjić, Marko
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Structural, optical, and photoluminescence properties of CdWO4 films synthesized by a chemical bath deposition method
(Walter de Gruyter GmbH, 2025-03-01)
Jovanovski, Stefan
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Breast Glandularity Distribution and Refining the Mean Glandular Dose Estimates in Digital Mammography
(Ovid Technologies (Wolters Kluwer Health), 2025-10)
Arifi, Mirjeta Mediji
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Background: In mammography, radiation dose is typically expressed as the mean glandular dose (MGD), which represents the dose delivered to the glandular tissue of the breast. Materials and Methods: This study compares MGD estimates obtained using three different methodologies: (I) MGD-Dance-Laboratory for Individualized Breast Radiodensity Assessment (LIBRA) – Calculated manually for each patient using Dance’s formula, incorporating mammographic breast density values derived from the LIBRA application, thereby replacing Dance’s standard glandularity assumption with image-specific values; (II) MGD-Dance – Calculated using Dance’s formula with the conventional assumption of 50% glandularity; (III) MGD-Displayed – Extracted directly from the Digital Imaging and Communication in Medicine header of each mammogram. Results: A total of 688 anonymized mammograms from 172 women undergoing routine screening were analyzed, with complete technical and patient-related data. The mean MGD values obtained by the three methods were: MGD-Dance-LIBRA: 2.97 mGy; MGD-Dance: 2.78 mGy; and MGD-Displayed: 2.81 mGy. The average glandularity across the dataset was estimated at 14%. A strong correlation was observed between MGD-Dance and MGD-Dance-LIBRA values (R² =0.9865). The refined dose estimation using image-specific glandularity from LIBRA consistently produced slightly higher values compared to the standard Dance method, highlighting the impact of the commonly assumed 50% glandularity, which overestimates the true average density. Conclusions: Incorporating individualized breast density estimates from the LIBRA application into Dance’s formula provides a more refined and accurate method for calculating MGD in digital mammography.
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Establishing Diagnostic Reference Levels in Digital Mammography from Eight Mammography Units Using over 30,000 Images
(MDPI AG, 2025-03-10)
Mediji-Arifi, Mirjeta
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Introduction: Diagnostic reference levels (DRLs) in digital mammography were determined from 31,040 digital mammography images acquired from diagnostic and screening examination data from eight state-managed mammography centers/units in the Republic of North Macedonia (RM). The main objective is to establish a diagnostic reference level for mammography examinations at different ranges of breast thickness. Materials and methods: Approximately 30,000 mammography images were used to evaluate mean glandular dose (MGD) and compressed breast thickness (CBT) for each projection, craniocaudal (CC) and mediolateral oblique (MLO). The stratified DRL was derived by calculating the 75th percentile of the MGD across all the samples at various CBT ranges for both projections. Results and Discussion: The overall median MGDs, minimum, and maximum were calculated to be 1.15 mGy, 0.1 mGy, and 9.93 mGy, respectively. As the CBT increased from 7 to 120 mm, the 75th percentile of the MGD increased from 0.94 mGy to 3.67 mGy for CC, and from 0.44 mGy to 4.91 mGy for MLO projections. Conclusions: The study established local DRLs for the digital mammography systems at the 75th percentile, which compared well with the values reported for other countries/regions. The DRL defined per CC and MLO image view for a specific CBT indicated that at least one mammography facility needs optimization.
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Formation of WO3 thin films from RF sputtered tungsten films by air annealing: A cost-effective approach
(National Library of Serbia, 2025)
Jovanovski, Stefan
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Popovic, Maja
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Novakovic, Mirjana
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Rajic, Vladimir
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WO3 thin films were prepared by RF sputtering metallic tungsten onto glass substrates, followed by thermal oxidation through annealing in air. This technique is straightforward, cost-efficient, and time-effective, achieving high deposition rates of 16 nm/min on average at 200 W magnetron power for the highly homogeneous W-metallic films. SEM/EDX analysis showed that after annealing at 450ᵒC in air, the RF sputtered 269 nm thick metallic W films with a round grain morphology (~30 nm) turned into 420 nm thick nearly stoichiometric transparent WO3 (tungsten (VI) oxide) film, with a dramatically changed morphology of aggregated crystal rods approximately 1 μm long. XRD and Raman spectroscopy confirmed a biphasic crystal structure, with a dominant monoclinic phase and a minor tetragonal phase. XPS analysis revealed the characteristic W4f7/2 and W4f5/2 electron peaks associated with the W6+ oxidation state, with no evidence of W5+ species, indicating a stoichiometric nature of the WO3 films.
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Pharmacokinetics of different selenium supplements in healthy individuals and patients with autoimmune thyroiditis after oral administration
(Society of Chemists and Technologists of Macedonia, 2025-06-24)
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Stafilov, Trajče
Selenium is essential for the function of key selenoproteins such as glutathione peroxidase, thiore-doxin reductase, and iodothyronine deiodinase, which have antioxidant properties and support thyroid hormone metabolism. Due to the low selenium content in European soils – particularly in the Southeast-ern regions, supplementation is often recommended, especially for conditions like Hashimoto's thyroidi-tis. However, careful consideration of selenium dosage and pharmacokinetics is crucial, as the margin be-tween essential and toxic levels is very narrow. The aim of this study was to investigate the pharmacoki-netics of selenium absorption and plasma concentration following oral administration of various selenium doses and chemical forms, both in the short and long term, in healthy individuals and patients with auto-immune thyroiditis. Selenium concentrations in blood plasma were measured using electrothermal atomic absorption spectrometry (ETAAS). The study found that L-selenomethionine is absorbed more efficiently than inorganic sodium selenite, with peak plasma concentrations reached and sustained within 6 – 8 hours. Selenium levels remained elevated 48 hours after ingestion compared to baseline. At a daily dose of 200 μg of selenium as L-selenomethionine, plasma selenium concentrations increased by approximate-ly 30 %, and by about 25 % at 100 μg/day, relative to the initial value. Long-term studies showed that plasma selenium concentrations rose significantly after the first month of supplementation, with a slower increase in subsequent months. After supplementation ended, selenium levels declined rapidly. Interest-ingly, no significant differences in selenium absorption or excretion were observed between patients with Hashimoto's thyroiditis and healthy controls.
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CENANGIUM OLYMPIUM, COMB. NOV.
(Macedonian Academy of Sciences and Arts, 2026-02-16)
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Wu, Gang
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Yang, Zhu-Liang
New records of the cup-fungus Zeus olympius Minter & Diam. (Rhytismataceae, Ascomycota) are reported from the territory of Kosovo, and a new taxonomic combination for the species is proposed. Phylogenetic analyses were conducted using nrITS (Nuclear ribosomal internal transcribed spacer) sequences from dry material collected in Kosovo and Greece. Based on the new phylogenetic placement, where species morphologically identified as Zeus olympius are placed within a clade of the genus Cenangium, Cenangium olympium (Minter & Diam.) M. Karadelev, K. Rusevska, G. Wu & Zhu L. Yang is introduced as a comb. nov. for Zeus olympius.
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Mycodiversity in the southwestern part of Jablanica mountain
(Acta Musei Macedonici Scientiarum Naturalium, 2024)

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