1. 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: 1
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2. Deeply-supervised 3D convolutional neural networks for automated ovary and follicle detection from ultrasound volumesBožidar Potočnik, Martin Šavc, 2022, original scientific article Abstract: Automated detection of ovarian follicles in ultrasound images is much appreciated when
its effectiveness is comparable with the experts’ annotations. Today’s best methods estimate follicles
notably worse than the experts. This paper describes the development of two-stage deeply-supervised
3D Convolutional Neural Networks (CNN) based on the established U-Net. Either the entire U-Net
or specific parts of the U-Net decoder were replicated in order to integrate the prior knowledge into
the detection. Methods were trained end-to-end by follicle detection, while transfer learning was
employed for ovary detection. The USOVA3D database of annotated ultrasound volumes, with its
verification protocol, was used to verify the effectiveness. In follicle detection, the proposed methods
estimate follicles up to 2.9% more accurately than the compared methods. With our two-stage CNNs
trained by transfer learning, the effectiveness of ovary detection surpasses the up-to-date automated
detection methods by about 7.6%. The obtained results demonstrated that our methods estimate
follicles only slightly worse than the experts, while the ovaries are detected almost as accurately as
by the experts. Statistical analysis of 50 repetitions of CNN model training proved that the training
is stable, and that the effectiveness improvements are not only due to random initialisation. Our
deeply-supervised 3D CNNs can be adapted easily to other problem domains.
Keywords: 3D deep neural networks, 3D ultrasound images of ovaries, deep supervision, detection of follicles and ovaries, U-Net based architecture Published in DKUM: 27.03.2025; Views: 0; Downloads: 6
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3. 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: 24
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4. 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: 20
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5. Study of ▫$Ni/Y_2O_3/polylactic$▫ acid compositeTilen Švarc, Matej Zadravec, Žiga Jelen, Peter Majerič, Blaž Kamenik, Rebeka Rudolf, 2023, original scientific article Abstract: This study demonstrates the successful synthesis of Ni/Y2O3 nanocomposite particles through the application of ultrasound-assisted precipitation using the ultrasonic spray pyrolysis technique. They were collected in a water suspension with polyvinylpyrrolidone (PVP) as the stabiliser. The presence of the Y2O3 core and Ni shell was confirmed with transmission electron microscopy (TEM) and with electron diffraction. The TEM observations revealed the formation of round particles with an average diameter of 466 nm, while the lattice parameter on the Ni particle’s surface was measured to be 0.343 nm. The Ni/Y2O3 nanocomposite particle suspensions were lyophilized, to obtain a dried material that was suitable for embedding into a polylactic acid (PLA) matrix. The resulting PLA/Ni/Y2O3 composite material was extruded, and the injection was moulded successfully. Flexural testing of PLA/Ni/Y2O3 showed a slight average decrease (8.55%) in flexural strength and a small decrease from 3.7 to 3.3% strain at the break, when compared to the base PLA. These findings demonstrate the potential for utilising Ni/Y2O3 nanocomposite particles in injection moulding applications and warrant further exploration of their properties and new applications in various fields. Keywords: ultrasound spray pyrolysis, Ni/Y2O3, lyophilization, PLA, extrusion, injection moulding Published in DKUM: 05.04.2024; Views: 199; Downloads: 22
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6. Early detection of neck lymph node metastases in breast cancer patients : the role of ultrasound and fine needle biopsyJanez Rebol, Peter Balon, Peter Kokol, Boštjan Lanišnik, Iztok Takač, Andraž Dovnik, Nina Fokter Dovnik, Monika Sobočan, Darja Arko, 2019, original scientific article Keywords: metastases, neck lymph, ultrasound, fine needle biopsy, breast canser Published in DKUM: 27.03.2024; Views: 225; Downloads: 6
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7. Contemporary approach to diagnostics in women with suspected pelvic endometriosisJure Knez, Andraž Dovnik, Maja Pakiž, Igor But, Milan Reljič, Vida Gavrić-Lovrec, Maja Banović, Iztok Takač, 2019, review article Keywords: endometriosis, endometrioma, ovarian cysts, deep pelvic endometriosis, ultrasound, pelvic pain Published in DKUM: 27.03.2024; Views: 258; Downloads: 15
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8. Combination of lung ultrasound (a comet-tail sign) and N-terminal pro-brain natriuretic peptide in differentiating acute heart failure from chronic obstructive pulmonary disease and asthma as cause of acute dyspnea in prehospital emergency settingGregor Prosen, Petra Klemen, Matej Strnad, Štefek Grmec, 2011, original scientific article Abstract: Introduction: We studied the diagnostic accuracy of bedside lung ultrasound (the presence of a comet tail sign), N-terminal pro-brain natriuretic peptide (NT-proBNP), and clinical assessment (modified Boston criteria) in differentiating heart failure (HF)- related acute dyspnea from pulmonary (COPD/asthma) related acute dyspnea in the prehospital setting.
Methods: Prospective study was performed at the Center for Emergency Medicine Maribor, Slovenia, between July 2007 and April 2010. Two groups of patients were compared: HF-related acute dyspnea group (n = 129) vs pulmonary-related (asthma/COPD) acute dyspnea group (n = 89). All patients underwent lung ultrasound examination, along with basic laboratory, rapid NT-proBNP testing and chest X-ray.
Results: Ultrasound comet tail sign has 100% sensitivity, 95% specificity, 100% negative predictive value (NPV) and 96% positive predictive value (PPV) for the diagnosis of HF. NT-proBNP (cut-off point 1000 pg/ml) has 92% sensitivity, 89% specificity, 86% NPV and 90% PPV. Boston modified criteria have 85% sensitivity, 86% specificity, 80% NPV and 90% PPV. Comparing the three methods, we found significant differences between ultrasound sign vs NT-proBNP (P<0.05) and Boston modified criteria (P<0.05). Combination of ultrasound sign and NT-proBNP has 100% sensitivity, 100% specificity, 100% NPV and 100% PPV. With ultrasound we can exclude HF in patients with pulmonary related dyspnea who have positive NT-proBNP (> 1000 pg/ml) and previous history of HF.
Conclusions: Ultrasound comet tail sign alone or in combination with NT-proBNP has a high diagnostic accuracy in differentiating between acute HF and COPD/asthma causes of acute dyspnea in prehospital emergency setting. Keywords: lungs, ultrasound, N-terminal pro-brain natriuretic peptide, acute heart failure, chronic obstructive pulmonary disease, asthma, acute dyspnea Published in DKUM: 29.06.2017; Views: 2008; Downloads: 405
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9. Programmable ultrasonic sensing system for targeted spraying in orchardsDenis Stajnko, Peter Berk, Mario Lešnik, Viktor Jejčič, Miran Lakota, Andrej Štrancar, Marko Hočevar, Jurij Rakun, 2012, original scientific article Abstract: This research demonstrates the basic elements of a prototype automated orchard sprayer which delivers pesticide spray selectively with respect to the characteristics of the targets. The density of an apple tree canopy was detected by PROWAVE 400EP250 ultrasound sensors controlled by a Cypress PSOC CY8C29466 microcontroller. The ultrasound signal was processed with an embedded computer built around a LPC1343 microcontroller and fed in real time to electro-magnetic valves which open/close spraying nozzles in relation to the canopy structure. The analysis focuses on the detection of appropriate thresholds on 15 cm ultrasound bands, which correspond to maximal response to tree density, and this was selected for accurate spraying guidance. Evaluationof the system was performed in an apple orchard by detecting deposits of tartrazine dye (TD) on apple leaves. The employment of programmable microcontrollers and electro-magnetic valves decreased the amountof spray delivered by up to 48.15%. In contrast, the reduction of TD wasonly up to 37.7% at some positions within the tree crown and 65.1% in the gaps between trees. For all these reasons, this concept of precise orchard spraying can contribute to a reduction of costs and environmental pollution, while obtaining similar or even better leaf deposits. Keywords: air-assisted sprayer, ultrasound, algorithm, programmable, microcontroller, spray distribution, orchard Published in DKUM: 22.06.2017; Views: 2341; Downloads: 531
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10. Case study of the sonochemical decolouration of textile azo dye Reactive Black 5Simona Vajnhandl, Alenka Majcen Le Marechal, 2007, original scientific article Abstract: The decolouration and mineralization of reactive dye C.I. Reactive Black 5, a well-known representative of non-biodegradable azo dyes, by means of ultrasonic irradiation at 20, 279 and 817 kHz has been investigated with emphasis on the effect of various parameters on decolouration and degradation efficiency. Characterization of the used ultrasound systems was performed using calorimetric measurements and oxidative species monitoring using Fricke and iodine dosimeter. Experiments were carried out with low frequency probe type, and a high-frequency plate type transducer at 50, 100 and 150 W of acoustic power and within the 5-300 mgžL initial dye concentration range. Decolouration, as well as radical production, increased with increasing frequency, acoustic power, and irradiation time. Any increase in initial dye concentration results in decreased decolouration rates. Sonochemical decolouration was substantially depressed by the addition of 2-methyl-2-propanol as a radical scavenger, which suggests radical-induced reactions in the solution. Acute toxicity to marine bacteria Vibrio fischeri was tested before and after ultrasound irradiation. Under the conditions employed in this study, no toxic compounds were detected after 6 h of irradiation. Mineralization of the dye was followed by TOC measurements. Relatively low degradation efficiency (50% after 6 h of treatment) indicates that ultrasound is rather inefficient in overall degradation, when used alone. Keywords: textile industry, wastewater treatment, textile dyeing, reactive dyes, azo dyes, decoloration, ultrasound, degradation, decoloration kinetics, oxidizing species Published in DKUM: 01.06.2012; Views: 2250; Downloads: 98
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