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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: 3
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Abstract: Temperature plays a crucial role in shaping the biology of insects. Developmental temperature and acclimation temperatures influence their ability to cope with extreme thermal conditions. This study investigates the effects of developmental temperatures during the pupal stage and adult acclimation temperatures on the thermal tolerance of Tenebrio molitor Linnaeus, 1758. We investigated cold tolerance based on chill-coma recovery time and heat tolerance based on heat knockdown time. Beetles were reared at five developmental temperatures (16, 21, 25, 30 and 35 °C) and later exposed to corresponding adult acclimation temperatures. From developmental temperatures of 21 and 30 °C, the group of beetles was subjected to different temperatures to induce adult acclimation at a different temperature than the developmental temperature. In cold-tolerance tests, beetles reared at lower temperatures showed better recovery from chill coma, while beetles reared at higher temperatures showed greater resistance to heat shock. Adult beetles acclimated to lower temperatures showed better cold tolerance, while those acclimated to higher temperatures performed better in the heat tolerance test. Interestingly, the developmental temperatures during the pupal stage also contributed to resistance, particularly in the heat tolerance test. However, pupal stage temperatures had no effect on cold-shock resistance, as indicated by chill-coma recovery time. The results could provide insights into the rearing of T. molitor.
Keywords: adult acclimation, cold tolerance, developmental acclimation, heat knockdown, heat tolerance, Tenebrio molitor, thermal tolerance, chill coma, yellow mealworm
Published in DKUM: 15.04.2025; Views: 0; Downloads: 4
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Abstract: Mast cell-activating signals in cold urticaria are not yet well defined and are likely to be heterogeneous. Cold agglutinins and cryoglobulins have been described as factors possibly associated with cold urticaria, but their relevance has not been explained. We performed a single-center prospective cohort study of 35 cold urticaria patients. Cold agglutinin and cryoglobulin test results, demographics, detailed history data, cold stimulation test results, complete blood count values, C-reactive protein, total immunoglobulin E levels, and basal serum tryptase levels were analyzed. Forty six percent (n = 16) of 35 tested patients had a positive cold agglutinin test and 27% (n = 9) of 33 tested patients had a positive cryoglobulin test. Cold agglutinin positive patients, when compared to cold agglutinin negative ones, were mainly female (P = 0.030). No gender-association was found for cryoglobulins. A positive cold agglutinin test, but not a positive cryoglobulin test, was associated with a higher rate of reactions triggered by cold ambient air (P = 0.009) or immersion in cold water (P = 0.041), and aggravated by increased summer humidity (P = 0.007). Additionally, patients with a positive cold agglutinin test had a higher frequency of angioedema triggered by ingestion of cold foods or drinks (P = 0.043), and lower disease control based on Urticaria Control Test (P = 0.023). Cold agglutinin levels correlated with erythrocyte counts (r = -0.372, P = 0.028) and monocyte counts (r = -0.425, P = 0.011). Cryoglobulin concentrations correlated with basal serum tryptase levels (r = 0.733, P = 0.025) and cold urticaria duration (r = 0.683, P = 0.042). Results of our study suggest that cold agglutinins and cryoglobulins, in a subpopulation of cold urticaria patients, are linked to the course and possibly the pathogenesis of their disease.
Keywords: cold-induced urticaria, cold urticaria, cryoglobulins, cold agglutinin, degranulation, clinical parameters, laboratory parameters, mast cells, cold triggers
Published in DKUM: 07.08.2024; Views: 104; Downloads: 10
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Abstract: In the present study engine/vehicle responses from a standardized transient test cycle are estimated using 13 stationary operating regimes following a previously developed methodology. The main advantage of the methodology tested is that allows obtaining an estimation of transient parameters in a stationary test bench, which requirements are much less demanding than those of the transient test bench. The objectives are: in one hand, to demonstrate that the methodology correctly estimates engine responses regardless of the fuel tested, as it is proposed in a previous paper and, on the other hand, to improve the methodology and the accuracy of the estimated parameters. The fuels tested are renewable fuels from different raw materials (biodiesel from rapeseed, sunflower, and soybean), and diesel fuel as the reference. Biodiesels were tested neat and blended (30% v/v) with diesel fuel. The engine is a common-rail light-duty one, and the standardized testing procedure used to illustrate the implementation of the methodology is the New European Driving Cycle (NEDC). Two design of experiments (DoE) of 13 runs each were analyzed. One of the DoE tested was proposed for characterizing the NEDC, referred as to CTDoE design, while the other one is a five-level fractional factorial design (FFDoE) that adequately matches the optimality criteria of orthogonality, D-optimal criterion, rotatability, and space-filling. The original methodology was improved by the implementation of a new fitting function that simulates the cold start effect over the engine parameters and by an new definition of the boundary in the [n,M] domain. These improvements showed significantly higher accuracy of the estimated engine parameters obtained, both instantaneous and accumulated, respect to the original methodology. The results obtained based on the application of the FFDoE design support the feasibility of the methodology tested. Engine performance and regulated emissions responses, such as intake air and fuel mass flow rate, thermomechanical exergy rate, exhaust gas residual heat rate, total hydrocarbons (THC), nitrogen oxides (NOx), carbon monoxide (CO) and particulate matter (PM) emissions from a transient test were instantaneously and cumulatively predicted with high accuracy using the engine responses from 13 steady-state operating modes.
Keywords: simulation, light duty diesel engine, transient cycle, biodiesel, design of experiments, cold start correction function
Published in DKUM: 21.09.2023; Views: 350; Downloads: 641
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Abstract: Urtikarijo zaradi hlada (UH), pri kateri se pojavijo s hladom izzvane urtike, angioedem ali oboje hkrati, delimo na tipično in atipično obliko. Diagnoza tipične UH temelji na pozitivnih lokalnih stimulacijskih testih (LST). Pri UH se lahko razvijejo tudi sistemske reakcije. Namen raziskave je bil določiti dejavnike tveganja za sistemske reakcije pri tipični UH. Mednarodna raziskava imenovana COLD-CE (tj. Urtikarija zaradi hlada in druge s hladom izzvane reakcije – celostno ovrednotenje) je potekala v 32 UCARE centrih (angl. Urticaria Center(s) of Reference and Excellence). Pridobili smo natančne anamnestične podatke in opravili LST s kocko ledu in/ali napravo TempTest®. Prizadetost dihal smo definirali kot dispnejo, piskanje ali stridor. Prizadetost kardiovaskularnega sistema smo definirali kot hipotenzijo ali izgubo zavesti in/ali druge simptome povezane s hipotenzijo (tj. omotica, občutek omedlevice ali nemoči). V raziskavo smo vključili 551 bolnikov z UH in 75 % od njih je imelo pozitivne LST (tj. tipično UH). Pri 40 bolnikih s tipično UH smo diagnosticirali tudi kronično spontano urtikarijo (KSU). Prizadetost dihal je nastopila pri 22 % in prizadetost kardiovaskularnega sistema pri 31 % bolnikov s tipično UH brez KSU. Ugotovili smo tri neodvisne dejavnike tveganja za prizadetost dihal: pričetek UH v otroštvu, orofaringealni in/ali laringealni simptomi ter srbež uhljev. Neodvisni dejavniki tveganja za prizadetost kardiovaskularnega sistema pa so: angioedem, orofaringealni in/ali laringealni simptomi, srbež uhljev ter predhodna sistemska reakcija na pik kožekrilca.
Keywords: COLD-CE, dejavniki tveganja, urtikarija zaradi hlada, sistemske reakcije
Published in DKUM: 29.11.2022; Views: 564; Downloads: 86
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