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Evaluation of phytochemicals and bioactivity in broccoli (Brassica oleracea var. italica) callus cultures in vitro.
No full textBroccoli (Brassica oleracea var. italica) is one of the most common cruciferous vegetables in the use worldwide, with antioxidant, anti-inflammatory, antimicrobial and neuroprotective properties. Due to its nutritional and health potential, it is common to use broccoli florets and sprouts for food, while the stems and leaves are waste at harvest. However, these under-utilised parts of the vegetable can also be used as functional food sources contributing to the prevention and treatment of certain chronic disorders. Phytohormones that regulate plant growth, development and cell differentiation and division are used to improve and ensure the desired concentrations of secondary metabolites synthesised by broccoli in laboratory methods. In this study, broccoli (Brassica oleracea var. italica) callus cultures were established in vitro, which differed in the composition of the nutrient media. Auxins (2,4-D) and cytokinins (BAP) together with amino acids (L-methionine and L-tryptophan) were used to supplement the nutrient media. After in vitro broccoli callus cultures were established, their antioxidant activity was assessed by different methods. The DPPH, ABTS and FRAP methods showed that supplementation of broccoli leaf, root and stem MS nutrient media with BAP (2 mg/l) and 2,4-D (0.2 mg/l) and L-methionine (100 µM) was the most effective in promoting the antioxidant properties. The evaluation of superoxide dismutase showed that the most significant activity of this enzyme in leaf and stem callus cultures was due to the addition of growth hormones BAP (2 mg/l) and 2,4-D (0.2 mg/l) to MS medium. The method for the evaluation of pigments showed that broccoli accumulates mainly carotenoids, and that the highest concentrations of carotenoids, especially in leaf callus culture, were due to the addition of amino acids to the nutrient media. The greatest effect on glucosinolate synthesis in differentiated broccoli tissues was due to the addition of L-methionine to MS medium. The concentrations of malondialdehyde, phenolic compounds and acids, proteins, flavonoids, L-proline and reduced glutathione were also evaluated in this study. A technological scheme for the extraction of glucosinolates from broccoli callus cultures was proposed
Hydrothermal synthesis and thermal stability of compounds formed in the CaO-TiO2-SiO2-H2O system.
No full textInfluence of 5-20 % amorphous TiO2 additive on gyrolite stechiometry corresponding CaO-SiO2- H2O system during hydrothermal synthesis at 200 °C was analysed. It was determined that the additive fully intercalates into synthesis products C-S-H(I)/(II), Z-phase and gyrolite as no TiO2 compounds have formed during hydrothermal curing. XRD results established that during 4-48 hour hydrothermal curing, CSH formation and recrystalization processes are accelerated in mixtures containing 5-15 % additive. The Most notable influence is identified in mixtures with 10 % of the additive. In these products, Z-phase has fully recrystalized into gyrolite after only 16-hour hydrothermal synthesis. Additionally, the largest gyrolite diffraction peaks are identified in 24-48 hour synthesis products with 10 % additive. Full additive intercalation is confirmed by STA as DSC curves indicate no effects attributed to TiO2 recrystalization processes. During calcination in 900 °C, amorphous TiO2 reacts with CSH, forming titanite. It was determined that the additive intercalates into synthetic Z-phase and gyrolite during hydrothermal curing. Relative to productssynthesized from raw materials, the additive reacts with CSH and forms titanite during calcination. To determine the influence of amorphous TiO2 concentration and hydrothermal curing duration on titanite formation, mixtures with molar ration of CaO:SiO2:TiO2=:1:1:0.90-1.10 were hydrothermally cured for 1 and 4 hours in 200 °C. Semi-crystaline C-S-H(I)/(II) compounds were identified in all hydrothermal synthesis products. During annealing in 900 °C temperature, synthesis products recrystalized into titanite and wollastonite mixture along with traces of, calcium titanite and brookite. It was determined that in experimental conditions, the largest amount of titanite (96.91 %) is formed in calcinated products when the duration of hydrothermal curing is one hour and and the concentration of amorphous TiO2 is 1.10 moles. It was determined that additional hydrothermal curing has a positive influence on raw materials reaction processes during calcination as titanite phase is not identified in hydrothermally untreated and calcinated raw mixtures
Investigation of antioxidant activity and phytochemical compounds in flax (Linum usitatissimum L.) callus cultures in vitro.
No full textFlax (Linum usitatissimum L.) is a valuable plant known for its nutritional and pharmacological properties, primarily due to its abundance of bioactive compounds such as lignans, phenols and unsaturated fatty acids. However, the natural concentrations of these metabolites are often insufficient for industrial use, and their accumulation is greatly influenced by genetic and environmental factors. In vitro culture methods, particularly the use of callus cultures, are a promising platform for enhancing the biosynthesis of secondary metabolites under controlled conditions. The aim of this study was to investigate the antioxidant activity and phytochemical compounds of flax (Linum usitatissimum L.) extracts obtained from in vitro callus cultures. The study evaluated the effects of physiologically active compounds – L-tryptophan, L-phenylalanine and melatonin – on flax seed callus cultures, in order to explore their biotechnological potential for the production of bioactive substances. The studies used callus cultures of flax roots, stems and leaves, which were grown in MS nutrient medium supplemented with various growth regulators and suppplements: 1-naphthylacetic acid, 6 benzylaminopurine, L-tryptophan, L-phenylalanine and melatonin. Spectrophotometric methods were used in the studies to assess antioxidant activity of flax: reducing power, FRAP, DPPH, ABTS methods, as well as various methods for determining the concentrations of phytochemical compounds. Callus cultures of flax have higher antioxidant activity than the control extract of flax grown in MS medium without growth regulators. In the obtained results, L-tryptophan provided greater antioxidant activity, although the use of melatonin also showed strong antioxidant protection. The lowest concentration of molondialdehyde were determined in extracts of flax callus cultures when the medium was supplemented with NAA (0.05 mg/L), BAP (0.5 mg/L) and L-tryptophan (0.5 mg/L). The studies determined that higher concentrations of proteins and phenolic compounds were obtained in extracts of callus cultures grown with NAA (0.05 mg/L); BAP (0.5 mg/L); L phenylalanine (1.25 g/L). When nutrient media were supplemented with L-tryptophan, led to elevated levels of superoxide dismutase, L-proline, phenolic acids, flavonoids, reduced glutathione, chlorophyll a, b and carotenoids
Teachers' professional development model: the case of school X.
No full textTeacher professional development is one of the key factors influencing the quality of contemporary schools, student achievement, and the overall culture of education. Recent research increasingly emphasizes not only formal aspects of professional development, but also the context in which teacher growth takes place. Although effective principles of professional learning are widely discussed in the literature, challenges remain in applying these principles to real school practice. Therefore, this study seeks to answer the question: what kind of professional development model can be effective in a specific school context? The object of the research is teacher professional development. The aim of the study is to substantiate a model of teacher professional development by applying it to the case of School X. The following objectives were set: 1) to theoretically justify a model of teacher professional development; 2) to substantiate the research methodology of the model; 3) to identify how the model manifests in the case of School X. In the theoretical part of the thesis, existing models of teacher professional development were analyzed and compared in order to identify their similarities, differences, and strengths. Based on this analysis, a new theoretical model was developed, consisting of five key components: organizational environment, individual professional development, leadership, collaboration, and reflection with feedback. This model later served as the analytical framework for the empirical part of the study. A qualitative research design was used, employing semi-structured interviews with teachers working at School X. The collected data was analyzed using qualitative content analysis by identifying key categories and subcategories. The findings revealed that the professional development system at School X is coherent, flexible, responsive to community needs, and empowers teachers to actively engage in shaping its content. The importance of leadership support, reflection, relevance of topics, and differentiation according to teacher experience was emphasized. In addition to the components outlined in theoretical models, the study revealed several additional factors that influence professional development: emotional well-being, personal readiness, workload, and topic relevance in specific situations. The proposed model may be applicable in other school contexts, provided it is adapted to the institution’s unique culture and structure. The research is relevant to school leaders, teaching communities, and researchers seeking to develop sustainable, context-sensitive professional development processes
The teachers‘ role in the education of students with high educational needs.
No full textIn recent decades, the increasing number of students with various learning difficulties has highlighted the importance of implementing inclusive education practices. Although the principles of inclusion are being actively integrated into Lithuania's education system, the education of students with significant and complex support needs remains one of the most challenging areas of pedagogical practice. These students often face complex developmental, behavioral, emotional, or communication difficulties that require consistent, long-term, and individualized pedagogical support. In such cases, the teacher’s role becomes a key factor in ensuring students’ learning opportunities, emotional well-being, and inclusion. This study aims to reveal the expression of the teacher’s role in educating students with complex learning and support needs, based on theoretical analysis and qualitative research findings. The theoretical part of the thesis discusses the concepts of “disability,” “disorder,” and “learning difficulties,” presents an overview of the development of special education in Lithuania, and analyzes the learning characteristics of these students as well as the importance of teacher competencies, preparedness, emotional resilience, and collaboration. Based on the analysis, a theoretical model of the teacher's role was developed. The qualitative research revealed that students with complex learning needs experience a wide range of challenges – behavioral, attentional, self-regulatory, language, emotional expression, and sensory difficulties – which make the provision of learning support complex and demand continuous individualization. The teachers’ experiences particularly highlighted the need to apply flexible, constantly adapted solutions tailored to the individual needs of each child. The effectiveness of support is significantly influenced by close cooperation with educational support specialists, teacher assistants, and students’ parents, as well as a clearly structured learning environment that includes tools, rules, visual aids, and emotional support. The study also showed that the challenges faced by teachers stem not only from students’ behavioral or developmental issues but also from insufficient institutional support, excessive workloads, emotional exhaustion, and a lack of professional development opportunities. Teacher resilience and commitment are sustained by a sense of responsibility, belief in change, self-reflection, and intrinsic motivation to work with these students. A teacher working with students with complex support needs functions not only as a provider of educational content but also as a source of emotional support, a creator of an inclusive environment, and a decision-maker in pedagogical practice. This mission is supported not only by professional knowledge but also by internal motivation, psychological preparedness, and well-structured institutional support. These factors enable the teacher to respond effectively to educational realities and to create sustainable, inclusive, and responsive learning environments
Research on wing aeroelastic effects suppression system.
No full textRecently, composite materials have been increasingly used in aircraft structure design due to their favorable mechanical properties. These materials offer a high strength-to-weight ratio, which is crucial in aviation; however, lightweight structures are more sensitive to aeroelastic instabilities such as flutter and divergence. Flutter is defined as a dynamic unstable vibration response, while divergence is a structural instability caused by excessive aerodynamic loads. To effectively suppress these phenomena, it is important to conduct research on aeroelastic suppression systems. After analyzing the literature on aeroelastic phenomena and existing suppression systems, it was found that the most effective are active suppression systems, which can dynamically adapt to changing loads and environmental conditions. The literature review showed that while various aeroelastic suppression methods are being investigated, no system using an electromagnetically controlled auxiliary mini-flap has been identified. Therefore, this work focuses on designing a new system that utilizes electromagnetically actuated mini-flap technology to suppress aeroelastic effects. Initially, a 3D model of a hypothetical unmanned aerial vehicle wing was created, and its strength, stiffness, and natural vibration characteristics were analyzed. The strength analysis revealed that the minimum safety factor according to the Tsai-Wu criterion is 1.52. The main vibration frequencies as well as the wing section’s bending and torsional stiffness were determined. Then, using a quasi-static method and a more advanced K-method, aeroelastic models of the wing were developed to identify key instability points. Calculations showed that divergence occurs first at a speed of 47.5 m/s, while flutter occurs at 54.5 m/s. Next, aerodynamic analysis of the airfoil was performed using “XFLR5“ software, during which the main characteristics of the profile were determined. The analysis revealed that the maximum absolute value of the pitching moment is Cm = 0.033. Based on this, a mini-flap with a 14% chord length and a 5° deflection angle was selected, covering 50% of the wing span. Aeroelastic mathematical models for damping were adapted based on the mini-flap configuration. Using the mini-flap as a passive damping element, the divergence speed increased from 47.5 m/s to 51.85 m/s. Dynamic vibration damping was analyzed at 47.5 m/s. When the mini-flap damping was activated after 0.5 seconds, the torsional oscillations were fully suppressed within approximately 0.4 seconds, and vertical wing motion also stabilized after 0.4 seconds. Finally, a conceptual prototype of the mini-flap system was developed, actuated by two electromagnets. Its structure was designed in SolidWorks and manufactured using 3D printing technology and steel plates. The prototype is operated using an Arduino Mega R3 microcontroller
In search of features of the holistic education paradigm in the Lithuanian primary education system.
No full textThe holistic education paradigm is a complex educational system aimed at nurturing the whole child by applying an integrated educational programme, holistic teaching methods, and fostering a holistic educational culture led by holistically minded teachers. The principles of interconnectedness, balance, inclusion, and spirituality are consistently upheld across all elements of this system. This dissertation examines the expression of the features of the holistic education paradigm within Lithuania’s primary education system. Based on complexity theory and the philosophical concept of holism, a multi-level mixed-methods study was conducted. Using a convergent data collection design, data were gathered through a systematic literature review, content analysis of documents, an online survey of Lithuanian primary school teachers (n = 365), lesson observations in primary education institutions (n = 30), and expert interviews with education policymakers (n = 5). In accordance with the principle of complementarity, quantitative and qualitative data were analysed separately and subsequently integrated through qualitative interpretation, grounded in the interpretivist paradigm. The study's findings revealed that all key features of holistic education are present within Lithuania’s primary education; however, the spiritual dimension was found to be the least evident. It was established that the current system is dominated by transaction-oriented experiential teaching methods, with a lack of transformative approaches and deep reflection, both of which are essential for nurturing spirituality. Spirituality plays a vital role in fostering ecological awareness and in developing an understanding of one’s role in the global context
The effects of strain amplitude and temperature on kinematic hardening parameters for low cycle fatigue of AISI316L stainless steel /
No full textTo perform a numerical simulation of low-cycle fatigue behaviour it is very important to model the elastoplastic behaviour of the material and for this, the proper estimation of the kinematic hardening parameters is a very critical part. The estimation of this kinematic hardening parameter is a very complex and time-consuming process. In the presented work, an experimental and numerical investigation of the low cycle fatigue behaviour of AISI316L stainless steel was carried out on the solid and hollow specimens with different strain amplitudes and temperatures. The simulation results were compared with the experimental data, and the agreement of these results was acceptable. On the basis of the results, preliminary equations for the estimation of kinematic hardening parameters are proposed, and the estimated parameters through these equations gave simulation results to the experimental results
New insights in fluid monitoring for surgical patients. A concept study /
No full textPurpose: This study evaluates the primary hypothesis of red cell mass (RCM) dependent amplitude of homeostatically acceptable limits of fluctuation in plasma dilution by exploring the correlation between RCM-specific equilibrated hematocrit (EQ_Hct) and amplitude of plasma dilution during perioperative mini Volume Loading Test (mVLT). Materials and methods: We retrospectively analyzed data from our previous RCTs, including 1,651 invasive arterial plasma dilution (aPD), 1,645 noninvasive “capillary” plasma dilution (cPD) and 236 estimates of EQ_Hct from 236 perioperative mVLT sessions. The cPD was estimated using noninvasive hemoglobin (SpHb, Masimo Radical 7, Irvine, CA) measurement. Fixed number of crystalloid boluses was used in 36 and 48 elective total knee arthroplasty (TKA) patients, and individualized number of boluses in 34 total hip arthroplasty (THA) patients for whom the number of boluses depended on the advices by our prototype automated clinical decision support system (ACDSS). Results: The primary hypothesis was confirmed—aPD decreased as EQ_Hct decreased when EQ_Hct <40%, and a very weak positive correlation was found between EQ_Hct and absolute aPD (Spearman's correlation coefficient 0.1025, p < 0.001). It was also confirmed when non-invasive data sets were used. A very weak negative correlation between HctEQ values and absolute cPD values (Spearman's correlation coefficient 0.0640, p = 0.0149). Conclusion: This study points to the feasibility of Photoplethysmography (PPG) based estimates of hemoglobin concentration for continuous noninvasive monitoring of fluid accumulation and detecting imminent edema using the Homeostatic Blood States (HBS) theory and transcapillary reflux model. The ACDSS-guided fluid loading has a potential to minimise unnecessary fluid accumulation. Further research is needed to explore and improve these techniques