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Povzetek: Essential oils are mixtures of volatile compounds often found in the leaves, wood, and fruits of coniferous trees and shrubs. The composition and abundance of individual oil components vary across different plant parts. Terpenes (monoterpenes, sesquiterpenes, diterpenes, triterpenes) dominate in the essential oils of many plants. They are the most abundant class of secondary metabolites, with plants containing over a hundred of them at varying concentrations. The terpene profile of certain species consists of a few dominant (abundant) components and numerous less abundant ones. It is believed that the biological activity of essential oil mostly depends on the dominant terpene components. In most of the analyzed Pinus species, the most abundant terpene compounds are α-pinene, β-pinene, δ-3-carene, β-caryophyllene, limonene/β-phellandrene, and germacrene D. In certain taxa, additional dominant compounds include α-cedrol, bornyl acetate, caryophyllene oxide, α-phellandrene, trimethylbicyclo [3.1.1]hept-2-ene, 2H-benzocyclohepten-2-one, phenylethyl butyrate, 4-epi-isocembrol, β-thujene, and thunbergol. Moreover, compounds with abundances exceeding 15% include methyl chavicol (=estragole), geranylene, myrcene, γ-muurolene, sabinene, and abieta-7,13-diene. It can be concluded that the terpene profiles of the needles of the analyzed pine taxa depend on the type of chromatographic columns, the method of obtaining essential oils, the origin of the trees (in natural habitat or artificial plantation), the age of the needles, the variety, and the season in which the needles were collected.
Ključne besede: needles, essential oil, Pinus taxa, variability, terpene profiles, terpene classes
Objavljeno v DiRROS: 27.02.2026; Ogledov: 62; Prenosov: 38
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Povzetek: JAK2 V617F (JAK2) mutation is associated with clonal hemopoiesis in myeloproliferative neoplasms as well as with faster progression of cardiovascular diseases. Little is known about the relationship between allele burden and the degree of atherosclerotic alteration of coronary vasculature. We previously reported that carotid artery stiffness progressed faster in patients with JAK2 positive essential thromocythemia (ET) patients. After a four-year follow-up we investigated whether mutation burden of a JAK2 allele correlates with a higher coronary calcium score. Patients and methods. Thirty-six patients with JAK2 positive ET and 38 healthy matched control subjects were examined twice within four years. At each visit clinical baseline characteristics and laboratory testing were performed, JAK2 mutation burden was determined, and coronary calcium was measured. Results. JAK2 allele burden decreased in 19 patients, did not change in 5 patients, and increased in 4 patients. The coronary calcium Agatston score increased slightly in both groups. Overall, there was no correlation between JAK2 allele burden and calcium burden of coronary arteries. However, in patients with the JAK2 mutation burden increase, the coronary calcium score increased as well. Conclusions. The average JAK2 allele burden decreased in our patients with high-risk ET during the four-year period. However, in the small subgroup whose JAK2 mutation burden increased the Agatston coronary calcium score increased as well. This finding, which should be interpreted with caution and validated in a larger group, is in line with emerging evidence that JAK2 mutation accelerates atherosclerosis and can be regarded as a non-classical risk factor for cardiovascular disease.
Ključne besede: essential thrombocythemia, JAK2 V617F mutation, JAK2 V617F allele burden
Objavljeno v DiRROS: 10.12.2025; Ogledov: 794; Prenosov: 142
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Povzetek: Introduction: Primidone and propranolol are primary treatments for essential tremor, however the exact mechanisms underlying their efficacy are not fully elucidated. Understanding how these medications alleviate tremor may guide the development of additional pharmacologic treatments. Our prospective observational study employed transcranial magnetic stimulation (TMS) to explore mechanisms of primidone and propranolol effects in essential tremor. Eyeblink classical conditioning (EBCC) was tested as a potential predictor of treatment response. Methods: Patients with essential tremor underwent two evaluations: prior to commencing primidone or propranolol and following a minimum of three months of treatment. Tremor severity was assessed using accelerometry and clinically. TMS was employed to study changes in corticospinal excitability - resting and active motor thresholds, resting and active input/output curves and intracortical excitability - cortical silent period (CSP), short interval intracortical inhibition intensity curve (SICI), long interval intracortical inhibition (LICI), intracortical facilitation (ICF), and short afferent inhibition (SAI). EBCC, a marker of cerebellar function, was studied at baseline. Results: Of the 54 enrolled patients (28 primidone, 26 propranolol), 35 completed both visits. Primidone effect on decreasing hand tremor was associated with decreased corticospinal excitability, prolongation of CSP, increased LICI, increased SAI and decreased SICI. Propranolol effect on hand tremor was associated with decreased corticospinal excitability and increased SAI. Better EBCC at baseline predicted better response to primidone. Conclusions: Primidone exerts its therapeutic effects by blocking voltage-gated sodium channels and by modulating GABA-A and GABA-B intracortical circuits. Propranolol's central effects are likely mediated via noradrenergic modulation of GABA outflow
Ključne besede: essential tremor, primidone and propranolol treatments
Objavljeno v DiRROS: 03.12.2025; Ogledov: 819; Prenosov: 131
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Povzetek: Molecular methods such as DNA/eDNA metabarcoding have emerged as useful tools to document the biodiversity of complex communities over large spatio-temporal scales. We established an international Marine Biodiversity Observation Network (ARMS-MBON) combining standardised sampling using autonomous reef monitoring structures (ARMS) with metabarcoding for genetic monitoring of marine hard-bottom benthic communities. Here, we present the data of our first sampling campaign comprising 56 ARMS units deployed in 2018–2019 and retrieved in 2018–2020 across 15 observatories along the coasts of Europe and adjacent regions. We describe the open-access data set (image, genetic and metadata) and explore the genetic data to show its potential for marine biodiversity monitoring and ecological research. Our analysis shows that ARMS recovered more than 60 eukaryotic phyla capturing diversity of up to ~5500 amplicon sequence variants and ~1800 operational taxonomic units, and up to ~250 and ~50 species per observatory using the cytochrome c oxidase subunit I (COI) and 18S rRNA marker genes, respectively. Further, ARMS detected threatened, vulnerable and non-indigenous species often targeted in biological monitoring. We show that while deployment duration does not drive diversity estimates, sampling effort and sequencing depth across observatories do. We recommend that ARMS should be deployed for at least 3–6 months during the main growth season to use resources as efficiently as possible and that post-sequencing curation is applied to enable statistical comparison of spatio-temporal entities. We suggest that ARMS should be used in biological monitoring programs and long-term ecological research and encourage the adoption of our ARMS-MBON protocols.
Ključne besede: 18S rRNA, COI, essential biodiversity variables, European marine omics biodiversity observation network, genetic monitoring, invasive species, ITS
Objavljeno v DiRROS: 18.04.2025; Ogledov: 790; Prenosov: 386
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Povzetek: We prove new inequalities and equalities for the generalized and the joint spectral radius (and their essential versions) of Hadamard (Schur) geometric means of bounded sets of positive kernel operators on Banach function spaces. In the case of nonnegative matrices that define operators on Banach sequences we obtain additional results. Our results extend results of several authors that appeared relatively recently.
Ključne besede: Hadamard-Schur geometric mean, Hadamard-Schur product, joint and generalized spectral radius, essential spectral radius, measure of noncompactness, positive kernel operators, non-negative matrices, bounded sets of operators
Objavljeno v DiRROS: 03.10.2024; Ogledov: 967; Prenosov: 543
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