1. Sustainable extraction of hemp seed and formulation extracts into organogels with analytical profiling of fatty acidssubcritical fluids in food processingSara Karlovšek, Taja Žitek Makoter, Teo Makoter, Željko Knez, Maša Knez Marevci, 2025, original scientific article Abstract: Sustainable extraction methods for natural extracts are crucial for mitigating environmental impact. Strategies that focus on waste reduction and resource efficiency contribute to long-term conservation. Hemp seeds, which were previously treated as waste product, are now valued for their nutrition and functional properties. This study investigated sustainable extraction methods for obtaining natural extracts from hemp seeds, with a focus on reducing environmental impact through efficient resource utilization and waste reduction. The extraction methods compared included supercritical fluid extraction (SFE), Soxhlet extraction (SOX), ultrasound-assisted extraction (UAE), cold maceration (CM), and cold pressing (CP). The contents of antioxidants, total phenols, and fatty acids in the extracts were analyzed via gas chromatography–mass spectrometry (GC–MS). The extracts were subsequently formulated into organogels to evaluate the stability of the fatty acids. The results showed that SFE and CP were the most efficient and environmentally friendly methods, with SFE allowing complete separation of the solvent from the extract. CP was also found to be effective and environmentally friendly. The study confirmed that formulating extracts in organogels effectively inhibited fatty acid oxidation, although a reduction in fatty acid content was observed during gel production. Overall, the formulation of extracts in organogels increased their stability, especially in preventing fatty acid degradation.
Keywords: supercritical fluid extraction, ultrasound extraction, cold pressing method, fatty acids, stability of formulations
Published in DKUM: 15.10.2025; Views: 0; Downloads: 6
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2. Open-source transformer-based information retrieval system for energy efficient robotics related literatureTine Bertoncel, 2025, original scientific article Abstract: Background and Purpose: This article employs the Hugging Face keyphrase-extraction-kbir-inspec machine learning model to analyze 654 abstracts on the topic of energy efficiency in systems and control, computer science and robotics. Methods: This study targeted specific arXiv categories related to energy efficiency, scraping and processing ab - stracts with a state-of-the-art Transformer-based Hugging Face AI model to extract keyphrases, thereby enabling the creation of related keyphrase networks and the retrieval of relevant scientific preprints. Results: The results demonstrate that state-of-the-art open-source machine learning models can extract valuable information from unstructured data, revealing prominent topics in the evolving field of energy-efficiency. Conclusion: This showcases the current landscape and highlights the capability of such information systems to pinpoint both well researched and less researched areas, potentially serving as an information retrieval system or early warning system for emerging technologies that promote environmental sustainability and cost efficiency.
Keywords: energy efficiency, keyphase extraction, early warning system, information system, semantic network, transformer models, industry 4.0
Published in DKUM: 07.08.2025; Views: 0; Downloads: 3
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3. The conversion of pistachio and walnut shell waste into valuable components with subcritical waterMaja Čolnik, Mihael Irgolič, Amra Perva, Mojca Škerget, 2024, original scientific article Abstract: Pistachio and walnut shells accumulate in large quantities as waste during food processing and represent a promising lignocellulosic biomass for the extraction of valuable components. Subcritical water technology was used as an environmentally friendly technique to study the extraction of active ingredients and other valuable degradation products from walnut and pistachio waste. Subcritical water extraction (SWE) was carried out under different process conditions (temperature (150–300 ◦C) and short reaction times (15–60 min)) and compared with conventional extraction using different organic solvents (acetone, 50% acetone and ethanol). The extracts obtained from pistachio and walnut shell waste are rich in various bioactive and valuable components. The highest contents of total phenols (127.08 mg GA/g extract at 300 ◦C for 15 min, from walnut shells), total flavonoids (10.18 mg QU/g extract at 200 ◦C for 60 min, from pistachio shells), total carbohydrates (602.14 mg TCH/g extract at 200 ◦C for 60 min, from walnut shells) and antioxidant activity (91% at 300 ◦C, for 60 min, from pistachio shells) were determined when the extracts were obtained via subcritical water. High contents of total phenols (up to 86.17 mg GA/g extract) were also determined in the conventional extracts obtained with ethanol. Using the HPLC method, sugars and their valuable derivatives were determined in the extracts, with glucose, fructose, furfurals (5-hydroxymethylfurfural (5-HMF) and furfural) and levulinic acid being the most abundant in the extracts obtained by subcritical water. The results show that subcritical water technology enables better exploitation of biowaste materials than conventional extraction methods with organic solvents, as it provides a higher yields of bioactive components such as phenolic compounds and thus extracts with high antioxidant activity, while at the same time producing degradation products that are valuable secondary raw materials.
Keywords: pistachio shells, walnut shells, subcritical water extraction, conventional extraction, waste biomass, valuable compounds, sugars, furfurals
Published in DKUM: 01.07.2025; Views: 0; Downloads: 8
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4. Weakly-supervised multilingual medical NER for symptom extraction for low-resource languagesRigon Sallauka, Umut Arioz, Matej Rojc, Izidor Mlakar, 2025, original scientific article Abstract: Patient-reported health data, especially patient-reported outcomes measures, are vital for improving clinical care but are often limited by memory bias, cognitive load, and inflexible questionnaires. Patients prefer conversational symptom reporting, highlighting the need for robust methods in symptom extraction and conversational intelligence. This study presents a weakly-supervised pipeline for training and evaluating medical Named Entity Recognition (NER) models across eight languages, with a focus on low-resource settings. A merged English medical corpus, annotated using the Stanza i2b2 model, was translated into German, Greek, Spanish, Italian, Portuguese, Polish, and Slovenian, preserving the entity annotations medical problems, diagnostic tests, and treatments. Data augmentation addressed the class imbalance, and the fine-tuned BERT-based models outperformed baselines consistently. The English model achieved the highest F1 score (80.07%), followed by German (78.70%), Spanish (77.61%), Portuguese (77.21%), Slovenian (75.72%), Italian (75.60%), Polish (75.56%), and Greek (69.10%). Compared to the existing baselines, our models demonstrated notable performance gains, particularly in English, Spanish, and Italian. This research underscores the feasibility and effectiveness of weakly-supervised multilingual approaches for medical entity extraction, contributing to improved information access in clinical narratives—especially in under-resourced languages.
Keywords: low-resource languages, machine translation, medical entity extraction, NER, NLP, patient-reported outcomes, weakly-supervised learning
Published in DKUM: 19.05.2025; Views: 0; Downloads: 4
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5. Natural Deep Eutectic Solvent-Based Matrix Solid Phase dispersion (MSPD) extraction for determination of bioactive compounds from sandy everlasting (Helichrysum arenarium L.) : a case of stability studyMilena Ivanović, Peter Krajnc, Aleš Mlinarič, Maša Islamčević Razboršek, 2022, original scientific article Abstract: In the present study, vortex-assisted matrix solid-phase dispersion (VA-MSPD) extraction
was used to isolate the major bioactive compounds from H. arenarium. To reduce the negative environmental impact of the conventionally used organic solvents, four different choline chloride-based
natural deep eutectic solvents (NADES) were investigated as possible eluents. The most influential
VA-MSPD extraction parameters: stationary phase (adsorbent), adsorbent/sample ratio, vortex time,
and volume of extraction solvent were systematically optimized. Ultrasound-assisted extraction
with 80% MeOH was used as the standard method for the comparison of results. The stability of the
obtained extracts was studied over a period of 0 to 60 days at three different temperatures (−18 ◦C,
4
◦C, and 25 ◦C). All extracts were evaluated both spectrophotometrically (determination of total
phenolic content (TPC) and antioxidant activity by ABTS and FRAP assay) and chromatographically
(HPLC-UV). NADES based on choline chloride and lactic acid (ChCl-LA) was selected as the most
effective extractant, with a determined TPC value of its extract of 38.34 ± 0.09 mg GA/g DW (27%
higher than the methanolic VA-MSPD extract) and high antioxidant activity. The content of individual phenolic compounds (chlorogenic acid, dicaffeoylquinic acid isomers, naringenin isomers,
and chalcones) in the ChCl-LA extract, determined by HPLC-UV, was comparable to that of the
conventionally obtained one. Moreover, the stabilization effect of ChCl-LA was confirmed for the
studied compounds: chlorogenic acid, naringenin-40
-O-glucoside, tomoroside A, naringenin-5-Oglucoside, isosalipurposide, and naringenin. The optimum VA-MSPD conditions for the extraction of
H. arenarium polyphenols were: florisil/sample ratio of 0.5/1, a vortex time of 2 min, and an elution
volume of ChCl-LA of 10 mL.
Keywords: matrix solid phase dispersion extraction, MSPD, natural deep eutectic solvents, NADES, extraction optimization, sandy everlasting, phenolic compounds, stability studies, antioxidant activity
Published in DKUM: 09.05.2025; Views: 0; Downloads: 9
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6. Synergistic effect of supercritical and ultrasound-assisted ginger (Zingiber officinale Roscoe) extractsTaja Žitek Makoter, Nika Kučuk, Vesna Postružnik, Maja Leitgeb, Željko Knez, Mateja Primožič, Maša Knez Marevci, 2022, original scientific article Abstract: Proper processing of natural material is crucial to obtain an extract with high content of
biologically active components. Dried, grinded ginger roots were extracted by ultrasonic method
and supercritical extraction with CO2
. The aim of the study was to determine if a mixture of the two
types of extracts attained by different methods and solvents exhibits better bioavailability than each
extract itself. Therefore, both extracts were analytically evaluated and then mixed in a ratio of 1:1.
The supercritical extract (SCG extract) and the mixed extract (mixG extract) had high antioxidant
activity (78% and 73%) and total phenols (827 mg/g ext. and 1455 mg/g ext.), which is also consistent
with the levels of gingerol (303 mg/g ext. and 271 g/g ext.) and shogaol (111 mg/g ext. and 100 g/g
ext.) in the extracts. In comparison to both pure extracts higher levels of total phenols were found
in the extract mixG. This could be the reason for the significant inhibition of melanoma cells and
antimicrobial potential (against Staphylococcus aureus, Escherichia coli, and Candida albicans). The
combination of the extracts resulted in a significant increase in the inhibition of selected microbial
and melanoma cells WM-266-4 compared to the control. Cell viability decreased below 60% when
mixG extract was applied. Antimicrobial activity has been confirmed.
Keywords: ginger, supercritical fluid extraction, ultrasound-assisted extraction, antimicrobial activity
Published in DKUM: 09.05.2025; Views: 0; Downloads: 13
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7. Optimisation of the green process of industrial hemp - preparation and its extract characterisationTaja Žitek Makoter, Petra Kotnik, Teo Makoter, Vesna Postružnik, Željko Knez, Maša Knez Marevci, 2022, original scientific article Abstract: Natural medicines and products are becoming increasingly important in the pharmaceutical
and food industries. The most important step in obtaining a natural remedy is the processing of
the natural material. This study offers the separation of the industrial hemp plant into fractions by
mechanical treatment, which has a significant impact on the selectivity of the obtained fractions. This
study also offers a solution to reduce waste by fractionating industrial hemp, focusing on the fraction
with the highest cannabinoid content (49.5% of CBD). The study confirmed the anticancer potential
of the extract, which prevents further division of WM-266-4 melanoma cells at a concentration of
10−3 mg/mL. However, application of the extract (c = 10−3 mg/mL) to normal human epidermal
melanocytes proved to be insignificant, as the metabolic activity of the cells was the same as in the
control cell group.
Keywords: supercritical fluid extraction, ultrasonic extraction, melanoma cells, extraction, WM-266-4
Published in DKUM: 09.05.2025; Views: 0; Downloads: 10
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8. Discrete time model for process meta language with fictitious-clockBoštjan Vlaovič, Aleksander Vreže, 2022, original scientific article Abstract: Industries like telecommunications, medical, automotive, military, avionics, and aerospace
use complex real-time systems. Specification and Description Language (SDL) is one of the leading
domain specific languages that is formally defined by international standards and well established in
describing such systems. To check system properties abstracted model of the system is prepared in
selected modeling language. We use Spin (Simple Promela Interpreter) model checker that is one of
the leading tools for verification of complex concurrent and reactive systems. This paper focuses on
modeling the SDL timer construct. It is one of the SDL constructs that is not easily modeled with
Promela, but is present in many SDL systems. After an overview of the related work we propose
a new Discrete Time Model for Promela (DTMP) that is seamlessly integrated in our framework
for modeling SDL systems and can be used with the mainstream version of the Spin tool. To the
best of our knowledge, this is not possible with the existing solutions. We describe how DTMP can
be used to model SDL systems that use timers. Experimental results demonstrate its applicability
to non-SDL systems with Fischer’s mutual exclusion protocol and the Parallel Acknowledgment
with Retransmission that were used in prior studies. We compare state-space requirements with
one of the existing solutions DT Promela and DT Spin. With that, virtues and shortcomings of this
high-level solution are exposed. We have shown that DTMP is effective when an extensive range of
timer expiration values are used, which is usually the case in real-life SDL systems.
Keywords: formal specifications, formal languages, discrete time, model checking, automated extraction, SDL, Promela, SpinRCP, Sdl2pml
Published in DKUM: 27.03.2025; Views: 0; Downloads: 6
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9. Supercritical fluid and conventional extractions of high value-added compounds from pomegranate peels waste: production, quantification and antimicrobial activity of bioactive constituentsKaja Kupnik, Maja Leitgeb, Mateja Primožič, Vesna Postružnik, Petra Kotnik, Nika Kučuk, Željko Knez, Maša Knez Marevci, 2022, original scientific article Abstract: This study is focused on different extractions (Cold Maceration (CM), Ultrasonic Extraction
(UE), Soxhlet Extraction (SE) and Supercritical Fluid Extraction (SFE)) of bioactive compounds from
pomegranate (Punica Granatum L.) fruit peels using methanol, ethanol, and acetone as solvents in
conventional extractions and changing operating pressure (10, 15, 20, 25 MPa) in SFE, respectively.
The extraction yields, total phenols (TP) and proanthocyanidins (PAC) contents, and antioxidant
activity of different extracts are revealed. TP and PAC recovered by extracts ranged from 24.22 to
42.92 mg gallic acid equivalents (GAE)/g and 2.01 to 5.82 mg PAC/g, respectively. The antioxidant
activity of extracts ranged from 84.70% to 94.35%. The phenolic compound identification and
quantification in selective extracts was done using the LC-MS/MS method. The contents of different
flavonoids and phenolic acids have been determined. SFE extract, obtained at 20 MPa, contained
the highest content (11,561.84 µg/g) of analyzed total polyphenols, with predominant ellagic acid
(7492.53 µg/g). For the first time, Microbial Growth Inhibition Rates (MGIRs) were determined at
five different concentrations of pomegranate SFE extract against seven microorganisms. Minimal
Inhibitory Concentration (MIC90) was determined as 2.7 mg/mL of SFE pomegranate peel extract in
the case of five different Gram-negative and Gram-positive bacteria.
Keywords: antimicrobial activity, antioxidants, bioactive compounds, extraction, LC-MS/MS, phenolics, phytochemistry, pomegranate, Punica Granatum L., secondary metabolites
Published in DKUM: 24.03.2025; Views: 0; Downloads: 15
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10. 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: 9
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