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Povzetek: Chitosan is a water-soluble polysaccharide with good adherence to negatively charged surfaces and reported antimicrobial and anti-inflammatory properties. Coating the surfaces of medical devices with chitosan is a promising strategy for harnessing these benefits. However, the surface properties of commercial polymers need to be altered to enable the bonding of thin chitosan films. In this study, the adhesion of chitosan onto plasma-treated polyvinyl chloride (PVC) and the metabolic activity of urothelial cells on chitosan-coated medical-grade PVC used for the synthesis of urinary catheters were evaluated. To improve the adhesion of chitosan onto the PVC catheters, PVC samples were made “super-hydrophilic”. PVC substrates were briefly treated with a powerful hydrogen plasma and weakly ionised oxygen plasma afterglow to obtain a chlorine-free surface film, which was rich in oxygen functional groups, followed by incubation of the plasma-treated substrates in an aqueous solution of chitosan. Then, urothelial RT4 cells were seeded on the treated and untreated PVC substrates, and their metabolic activity, confluency, and cell morphology were examined. X-ray photoelectron spectroscopy was used to measure the nitrogen concentration, which corresponded to the chitosan concentration on the substrate. The results showed that the substrates were uniformly covered by a thin layer of chitosan only on plasma-treated surfaces and not on untreated surfaces. Moreover, the chitosan coating provided a stimulated environment for cell adhesion and growth. In conclusion, the chitosan-coated super-hydrophilic PVC substrate shows potential to improve the overall performance and safety of medical devices such as urinary catheters.
Ključne besede: medical-grade PVC, chitosan coating, urinary catheter, urothelial cells, cytotoxicity, adhesion, biocompatibility
Objavljeno v DiRROS: 28.02.2025; Ogledov: 46; Prenosov: 19
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Povzetek: Gymnosperms are a very old and small group of plants compared to angiosperms. Contemporary science recognizes about 650 extant conifers worldwide. This review focuses on species of the Pinaceae family found in Europe. There are 23 species from the genera Abies, Larix, Picea, and Pinus. Some of them are widespread in Europe, but others have fragmented and limited distribution and are classified as relic, endemic, or endangered. The aim of this review is providing cumulative information about the variability of needle morpho-anatomy, terpenes, and n-alkanes, as well as the genetics of the Pinaceae species, native to Europe. The first morpho-anatomical examinations of needles were conducted in the 19th century. A lot of species have been investigated up to now, but the population variability of many conifer species is still not known. The composition and abundance of terpenes differ between genera and families but also within the same genus, pointing to their taxonomic importance. n-Alkanes on the needle wax surfaces of conifers are sometimes very useful markers of species and population variability. The most abundant n-alkanes in Abies species are nonacosane (C29), hentriacontane (C31), or heptacosane (C27), whereas in Larix decidua and the majority of Picea species, C31 is predominant. C31 and C29 are the dominant n-alkanes in the genus Pinus. The most extensive population-genetic studies of European representatives of the Pinaceae family have focused on Abies alba, Picea abies, Pinus nigra, and Pinus sylvestris, but also examined endemic species such as Abies borisii-regis, A. cephalonica, A. nebrodensis, and Picea omorika. These studies hold significant practical value in assessing species’ evolutionary potential, devising strategies for long-term species conservation, identifying centers of diversity, detecting relict and ancestral populations, unveiling cryptic species and hybrids, and elucidating the taxonomic significance of species. These investigations are of great value not only on the biodiversity level, but also on the levels of ecology, physiology, taxonomy, and evolution.
Ključne besede: Europe, Pinaceae, conifers, needle morphology, needle anatomy, terpenes, n-alkanes, genetic markers
Objavljeno v DiRROS: 27.02.2025; Ogledov: 77; Prenosov: 52
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Objavljeno v DiRROS: 27.02.2025; Ogledov: 76; Prenosov: 13
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Povzetek: Parkinson’s disease (PD) is a progressive neurodegenerative disorder, with pharmacological treatments predominantly focusing on dopaminergic therapies. In the early stages of PD, symptoms may also be alleviated through non-pharmacological interventions. One such non-invasive technique is electroencephalogram neurofeedback (EEG NFB), which has shown promising results in improving the cognitive and motor functions of PD patients. The aim of our study was to assess the existing evidence, identify key trends and determine potential opportunities for future research in the field of EEG NFB for PD. This analysis explores the impact of EEG NFB on motor deficits in PD and identifies key factors for the successful implementation of EEG NFB as evidenced in the literature. The synthesis includes findings from five relevant studies, including one case study, one pilot study and three randomized controlled trials. Study selection followed the PICO framework to ensure relevance and rigor. The results suggest a correlation between sensorimotor rhythm (SMR) and beta rhythms, with increases in SMR (13–15 Hz) and beta (12–15 Hz) rhythms linked to improvements in balance, mobility and stability in PD patients. However, limitations such as small sample sizes, brief intervention durations and lack of follow-up warrant a cautious interpretation. Future research should prioritize robust protocols, larger samples and extended neurofeedback training to fully assess EEG NFB’s potential for PD management.
Ključne besede: Parkinson's disease, motor deficits, biofeedback, neurofeedback, electroencephalography
Objavljeno v DiRROS: 27.02.2025; Ogledov: 78; Prenosov: 54
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