1. Improved relation extraction through key phrase identification using community detection on dependency treesShuang Liu, Xunqin Chen, Jiana Meng, Niko Lukač, 2025, original scientific article Abstract: A method for extracting relations from sentences by utilizing their dependency trees to identify key phrases is presented in this paper. Dependency trees are commonly used in natural language processing to represent the grammatical structure of a sentence, and this approach builds upon this representation to extract meaningful relations between phrases. Identifying key phrases is crucial in relation extraction as they often indicate the entities and actions involved in a relation. The method uses community detection algorithms on the dependency tree to identify groups of related words that form key phrases, such as subject-verb-object structures. The experiments on the Semeval-2010 task8 dataset and the TACRED dataset demonstrate that the proposed method outperforms existing baseline methods. Keywords: community detection algorithms, dependency trees, relation extraction Published in DKUM: 17.01.2025; Views: 0; Downloads: 2
Full text (3,12 MB) |
2. Optimization of the supercritical extraction and decarboxylation process of industrial hempTaja Žitek Makoter, Petra Kotnik, Teo Makoter, Željko Knez, Maša Knez Marevci, 2025, original scientific article Abstract: Cannabinoids are the main active ingredients of Cannabis sativa L., obtained by a suitable extraction method and decarboxylation, in which the acid forms of the cannabinoids are converted into active forms. Supercritical CO2 extraction method and decarboxylation process were optimized for 7 cannabinoids (CBD, CBDA, THC, THCA, CBGA, CBN and CBC). The optimal extraction conditions for all cannabinoids were determined at a temperature of 60 °C and a pressure of 300 bar to 550 bar. At higher temperatures and reaction times, a significant depletion of neutral cannabinoids was observed. The optimal conditions of the decarboxylation process varied depending on the component. For the CBD component, which could be measured in the highest concentrations (560 mg/g), the optimal conditions were 140 °C and 10 min. The study can be an important model for predicting the behavior of cannabinoids under certain parameters. Keywords: supercritical fluids, extraction, cannabinoids, decarboxilation, Cannabis sativa I Published in DKUM: 08.01.2025; Views: 0; Downloads: 2
Full text (10,15 MB) |
3. |
4. Identification and content of astaxanthin and its esters from microalgae Haematococcus pluvialis by HPLC-DAD and LC-QTOF-MS after extraction with various solventsBiljana Todorović, Jaša Veno Grujić, Andreja Urbanek Krajnc, Roman Kranvogl, Jana Ambrožič-Dolinšek, 2021, original scientific article Abstract: Haematococcus pluvialis, a unicellular green microalga that produces a secondary metabolite under stress conditions, bears one of the most potent antioxidants, namely xanthophyll astaxanthin. The aim of our study was to determine the content of astaxanthin and its esterified forms using three different solvents—methyl tert-butyl ether (MTBE), hexane isopropanol (HEX -IPA) and acetone (ACE)—and to identify them by using high performance liquid chromatography coupled with diode array detection and the quadrupole time-of-flight mass spectrometry (HPLC-DAD and LC-QTOF-MS) technique. We identified eleven astaxanthin monoesters, which accounted for 78.8% of the total astaxanthin pool, six astaxanthin diesters (20.5% of total), while free astaxanthin represented the smallest fraction (0.7%). Astaxanthin monoesters (C16:2, C16:1, C16:0), which were the major bioactive compounds in the H. pluvialis samples studied, ranged from 10.2 to 11.8 mg g−1 DW. Astaxanthin diesters (C18:4/C18:3, C18:1/C18:3) were detected in the range between 2.3 and 2.6 mg g−1 DW. All three solvents were found to be effective for extraction, but MTBE and hexane-isopropanol extracted the greatest amount of free bioactive astaxanthin. Furthermore, MTBE extracted more low-chain astaxanthin monoesters (C16), and hexane-isopropanol extracted more long-chain monoesters (C18 and above) and more diesters. We can conclude that MTBE is the solvent of choice for the extraction of monoesters and hexane-isopropanol for diesters. Keywords: astaxanthin diesters, astaxanthin monoesters, carotenoids, Hematococcus pluvialis, astaxanthin diesters, solvent extraction Published in DKUM: 22.11.2024; Views: 0; Downloads: 6
Full text (1,83 MB) This document has many files! More... |
5. Ellagitannin content in extracts of the chestnut wood aesculusTaja Žitek Makoter, Maša Knez Marevci, Željko Knez, 2024, original scientific article Keywords: antioxidant activity, chestnut wood, conventional extraction, extraction, fractionation, polyphenols, tannins, ultrasound extraction Published in DKUM: 05.09.2024; Views: 70; Downloads: 16
Full text (1,27 MB) |
6. Eco friendly functional finishes of polyester fabric using keratin from wool and feather wastesLidija Fras Zemljič, Maja Čolnik, Darinka Fakin, Tanja Pušić, Vanessa Wendy Bračko, Tjaša Kraševac Glaser, Mojca Škerget, 2024, original scientific article Abstract: This research showcases the use of hydrothermally extracted solutions from poultry feathers and wool as ecofriendly and versatile textile finishes. These solutions, derived from waste biomass containing the keratin
biopolymer, were obtained through environmentally conscious hydrothermal degradation processes. Initially,
the study focused on analysing the chemical parameters and properties of both dialysed and non-dialysed solutions extracted from feathers and wool. The investigation tracked primarily the presence of keratin within these
solutions. Upon application to polyester textiles as the reference material, the presence of these solutions on the
fabric surface was confirmed successfully. A thorough physicochemical analysis of the treated textiles involved
various analytical techniques. These encompassed surface composition analysis via X-ray Photoelectron Spectroscopy (XPS) and Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR), assessment of wettability through Contact Angle measurements, determination of surface charge using surface zeta
potential, and examination of the thermal and flame-retardant properties via Differential Scanning Calorimetry
(DSC), Thermogravimetric Analysis (TGA), and calorimetric tests. In addition, the colour, UV radiation transmission and antioxidant activity were evaluated using standard tests.
The remarkable effects of the treatment have been observed in the exceptional antioxidative action, fire
resistance, UV protection and enhanced hydrophilicity of these innovative multifunctional textiles. This
approach holds significant implications across research, economics and society, enriching Material Science by
deepening the understanding of materials and their multifaceted properties. Moreover, it promotes resource
efficiency, opens new sustainable textile market prospects, and contributes to social impact by supporting
environmental sustainability, engaging communities and ensuring health and safety benefits. Keywords: poultry feathers and wool, hydrothermal extraction, polyester, finishing, green, multifunctionality Published in DKUM: 03.09.2024; Views: 43; Downloads: 16
Full text (1,87 MB) This document has many files! More... |
7. Antibacterial Komagataeibacter hansenii nanocellulose membranes with avocado seed bioactive compoundsKaja Kupnik, Mateja Primožič, Vanja Kokol, Željko Knez, Maja Leitgeb, 2024, original scientific article Keywords: bacterial nanocellulose membrane, avocado seed extracts, extraction, swelling, release, antibacterial activity Published in DKUM: 23.08.2024; Views: 70; Downloads: 4
Full text (1,80 MB) |
8. Extraction of active compounds from mixtures of hemp (Cannabis sativa) with Pants of the Zingiberaceae familyVesna Postružnik, Taja Žitek Makoter, Darko Goričanec, Petra Kotnik, Željko Knez, Maša Knez Marevci, 2023, original scientific article Keywords: supercritical fluid extraction, ultrasound-assisted extraction, hemp, ginger, turmeric, cardamom Published in DKUM: 08.05.2024; Views: 234; Downloads: 13
Full text (2,36 MB) This document has many files! More... |
9. Zero-Waste Approach for Heavy Metals’ Removal from Water with an Enhanced Multi-Stage Hybrid Treatment SystemDanijela Urbancl, Darko Goričanec, Marjana Simonič, 2023, original scientific article Keywords: river sediment, heavy metals, extraction process, EDTA, citric acid, natural clay Published in DKUM: 08.05.2024; Views: 187; Downloads: 18
Full text (4,29 MB) This document has many files! More... |
10. Helichrysum italicum : From Extraction, Distillation, and Encapsulation Techniques to Beneficial Health EffectsVeronika Furlan, Urban Bren, 2023, review article Abstract: Helichrysum italicum (family Asteraceae), due to its various beneficial health effects, represents an important plant in the traditional medicine of Mediterranean countries. Currently, there is a renewed interest in this medicinal plant, especially in investigations involving the isolation and identification of its bioactive compounds from extracts and essential oils, as well as in experimental validation of their pharmacological activities. In this paper, we review the current knowledge on the beneficial health effects of Helichrysum italicum extracts, essential oils, and their major bioactive polyphenolic compounds, ranging from antioxidative, anti-inflammatory, and anticarcinogenic activities to their antiviral, antimicrobial, insecticidal, and antiparasitic effects. This review also provides an overview of the most promising extraction and distillation techniques for obtaining high-quality extracts and essential oils from Helichrysum italicum, as well as methods for determining their antioxidative, antimicrobial, anti-inflammatory, and anticarcinogenic activities. Finally, new ideas for in silico studies of molecular mechanisms of bioactive polyphenols from Helichrysum italicum, together with novel suggestions for their improved bioavailability through diverse encapsulation techniques, are introduced. Keywords: Helichrysum italicum, polyphenolic compounds, biological effects, extraction methods, distillation methods, encapsulation methods Published in DKUM: 15.03.2024; Views: 327; Downloads: 12
Full text (2,78 MB) This document has many files! More... |