bluuebunny/crossref_metadata_2025 huggingface dataset:
Ethanol foam: a novel type of foam sclerosant for treating venous malformations
Authors: Zhang Han-Shu , Liu Yi-Ran , Liu Shao-Hua
Published: August 2024

Introduction

Sclerotherapy is a commonly utilized treatment approach for venous malformations. Absolute ethanol is renowned for its remarkable efficacy as a potent sclerosants, but it is potentially associated with severe complications. Foam sclerotherapy is considered superior to liquid sclerotherapy owing to its heightened efficacy and diminished incidence of complications. Thus, our objective was to devise an ethanol foam sclerosant that delivers exceptional efficacy while mitigating complications.

Methods

In the first set of experiments, we identified the suitable range of ethanol concentrations for sclerotherapy through human umbilical vein endothelial cell proliferation assays and blood clotting experiments. Next, the surfactants polysorbate 80, egg yolk lecithin, and hyaluronic acid were added to create stable ethanol foam, with their ratios meticulously optimized.

Results

The optimal concentration range of ethanol was determined to be 30–60%. Eventually, a 48% ethanol foam was successfully produced with excellent stability. Other than ethanol, the formulation included 5 × 10−3 g/mL polysorbate 80, 10−2 g/mL egg yolk lecithin, and 0.04 mL/mL hyaluronic acid.

Discussion

The novel ethanol foam produced here could be a promising candidate for the treatment of venous malformations.
White matter integrity in hospitalized COVID-19 patients is not associated with short- and long-term clinical outcomes
Authors: van Lith Theresa J. , Li Hao , van der Wijk Marte W. , Wijers Naomi T. , Sluis Wouter M. , Wermer Marieke J. H. , de Leeuw Frank-Erik , Meijer Frederick J. A. , Tuladhar Anil M.
Published: August 2024

Objectives

SARS-CoV-2 infection is associated with a decline in functional outcomes; many patients experience persistent symptoms, while the underlying pathophysiology remains unclear. This study investigated white matter (WM) integrity on brain MRI in hospitalized COVID-19 patients and its associations with clinical outcomes, including long COVID.

Materials and methods

We included hospitalized COVID-19 patients and controls from CORONavirus and Ischemic Stroke (CORONIS), an observational cohort study, who underwent MRI-DWI imaging at baseline shortly after discharge (<3 months after positive PCR) and 3 months after baseline scanning. We assessed WM integrity using diffusion tensor imaging (DTI) and neurite orientation dispersion and density imaging (NODDI) and performed comparisons between groups and within patients. Clinical assessment was conducted at 3 and 12 months with functional outcomes such as modified Rankin Scale (mRS), Post-COVID-19 Functional Status scale (PCFS), Visual Analogue Scale (VAS), and long COVID, cognitive assessment was conducted by the Modified Telephone Interview for Cognitive Status (TICS-M), and the Hospital Anxiety and Depression Scale (HADS) was used to assess mood disorder. Associations between WM integrity and clinical outcomes were evaluated using logistic regression and linear regression.

Results

A total of 49 patients (mean age 59.5 years) showed higher overall peak width of skeletonized mean diffusivity (PSMD) (p = 0.030) and lower neurite density index (NDI) in several WM regions compared with 25 controls at the baseline (p < 0.05; FWE-corrected) but did not remain statistically significant after adjusting for WM hyperintensities. Orientation dispersion index (ODI) increased after 3-month follow-up in several WM regions within patients (p < 0.05), which remained significant after correction for changes in WMH volume. Patients exhibited worse clinical outcomes compared with controls. Low NDI at baseline was associated with worse performance on the Post-COVID-19 Functional Status scale after 12 months (p = 0.018).

Conclusion

After adjusting for WMH, hospitalized COVID-19 patients no longer exhibited lower WM integrity compared with controls. WM integrity was generally not associated with clinical assessments as measured shortly after discharge, suggesting that factors other than underlying WM integrity play a role in worse clinical outcomes or long COVID.
Multiple sclerosis in LRRK2 G2019S Parkinson’s disease and isolated nigral degeneration in a homozygous variant carrier
Authors: Wise Adina , Ortega Roberto A. , Raymond Deborah , Cervera Alessandra , Thorn Emma , Leaver Katherine , Russell David S. , Bressman Susan B. , Crary John F. , Saunders-Pullman Rachel
Published: August 2024

Background

LRRK2 variants have been associated with immune dysregulation as well as immune-related disorders such as IBD. A possible relationship between multiple sclerosis (MS) and LRRK2 PD has also been suggested. Further, neuropathologic studies of homozygous LRRK2 G2019S carriers with Parkinson’s disease (PD) are rare, and there are no systematic reports of clinical features in those cases.

Methods

We investigated the co-occurrence of PD and MS in our research cohort and report on two cases of MS in LRRK2 PD as well as neuropathological findings for one.

Results

MS preceded PD in 1.4% (2/138) of participants with LRRK2 G2019S variants, and in none (0/638) with idiopathic PD (p = 0.03). One case with MS and PD was a LRRK2 G2019S homozygous carrier, and neuropathology showed evidence of substantia nigra pars compacta degeneration and pallor without Lewy deposition, as well as multiple white matter lesions consistent with MS-related demyelination.

Discussion

The increased prevalence of MS in LRRK2 PD further supports an important role for immune function for LRRK2 PD. This co-occurrence, while rare, suggests that MS may be an expression of the LRRK2 G2019S variant that includes both MS and PD, with MS predating features diagnostic of PD. The neuropathology suggests that the MS-related effects occurred independent of synuclein deposition. Importantly, and in addition, the neuropathological results not only support the MS diagnosis, but provide further evidence that Lewy body pathology may be absent even in homozygote LRRK2 carriers.
Glucosinolate extract from radish (Raphanus sativus L.) seed attenuates high-fat diet-induced obesity: insights into gut microbiota and fecal metabolites
Authors: Zhu Quanfeng , Zhang Peng , Liu Daqun , Tang Leilei , Yu Jiawen , Zhang Chengcheng , Jiang Guojun
Published: August 2024

Background

Radish seed is a functional food with many beneficial health effects. Glucosinolates are characteristic components in radish seed that can be transformed into bioactive isothiocyanates by gut microbiota.

Objective

The present study aims to assess anti-obesity efficacy of radish seed glucosinolates (RSGs) and explored the underlying mechanisms with a focus on gut microbiota and fecal metabolome.

Methods

High-fat diet-induced obese mice were supplemented with different doses of RSGs extract for 8 weeks. Changes in body weight, serum lipid, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) levels; and pathological changes in the liver and adipose tissue were examined. Fecal metabolome and 16S rRNA gene sequencing were used to analyze alterations in fecal metabolite abundance and the gut microbiota, respectively.

Results and conclusion

Results showed that RSG extract prevented weight gain and decreased serum lipid, ALT, AST levels and lipid deposition in liver and epididymal adipocytes in obese mice. Treatment with RSG extract also increased gut microbiota diversity and altered the dominant bacteria genera in the gut microbiota, decreasing the abundance of Faecalibaculum and increasing the abundance of Allobaculum, Romboutsia, Turicibacter, and Akkermansia. Fecal metabolome results identified 570 differentially abundant metabolites, of which glucosinolate degradation products, such as sulforaphene and 7-methylsulfinylheptyl isothiocyanate, were significantly upregulated after RSG extract intervention. Furthermore, enrichment analysis of metabolic pathways showed that the anti-obesity effects of RSG extract may be mediated by alterations in bile secretion, fat digestion and absorption, and biosynthesis of plant secondary metabolites. Overall, RSG extract can inhibit the development of obesity, and the obesity-alleviating effects of RSG are related to alternative regulation of the gut microbiota and glucosinolate metabolites.
Discrimination of 14 olive cultivars using morphological analysis and machine learning algorithms
Authors: Blazakis Konstantinos N. , Stupichev Danil , Kosma Maria , El Chami Mohamad Ali Hassan , Apodiakou Anastasia , Kostelenos George , Kalaitzis Panagiotis
Published: August 2024

Traditional morphological analysis is a widely employed tool for the identification and discrimination of olive germplasm by using morphological markers which are monitored by subjective manual measurements that are labor intensive and time-consuming. Alternatively, an automated methodology can quantify the geometrical features of fruits, leaves and endocarps with high accuracy and efficiency in order to define their morphological characteristics. In this study, 24 characteristics for fruits, 16 for leaves and 25 for endocarps were determined and used in an automated way with basic classifiers combined with a meta-classsifier approach. This resulted to the discrimination of 14 olive cultivars utilizing data obtained from two consecutive olive growing periods. The cultivar classification algorithms were based on machine learning techniques. The 95% accuracy rate of the meta-classifier approach indicated that was an efficient tool to discriminate olive cultivars. The contribution of each morphological feature to cultivar discrimination was quantified, and the significance of each one was automatically detected in a quantitative way. The higher the contribution of each feature, the higher the significance for cultivar discrimination. The identification of most cultivars was guided by the features of both endocarps and fruits, while those of leaves were only efficient to identify the Kalamon cultivar. The combined use of morphological features of three olive organs might have an additive effect leading to higher capacity for discrimination of cultivars. The proposed methodology might be considered a phenomics tool for olive cultivar identification and discrimination in a wide range of applications including breeding.
Focusing with colorectal cancer patients: a pilot study of a brief online group intervention
Authors: Gomes Marta , Silva Eunice R. , Salgado João
Published: August 2024

Introduction

Focusing-Oriented Psychotherapy has had a long history and influence on the field of psychotherapy. By “clearing a space” and “focusing,” individuals can enhance their emotional awareness and improve their ability to self-regulate. These tasks are particularly relevant in the context of Psycho-Oncology, although the research on their potential benefits for cancer patients is limited. Furthermore, the application of these tasks in a group or online setting has not been thoroughly explored.

Methods

This study aimed to examine the effectiveness of a two-session online intervention based on Focusing for cancer-diagnosed participants and its impact on their mental health and wellbeing. The study involved three participants with a diagnosis of colorectal cancer who were undergoing palliative treatment. We used both qualitative and quantitative methods. PFC-2 was used to assess participants' accomplishment of the task; FMS was used to assess the change in the focusing attitude, while CORE-OM, and PWBS-RV were used as mental health distress and psychological wellbeing measures; participant feedback was collected through questionnaires and a semi-structured interview.

Results

The results suggest that the tasks led to greater self-awareness, heightened self-reflection, and a sense of relief for the participants.

Discussion

These findings suggest that the group intervention protocol based on online Focusing sessions is potentially useful for broader applications.
Trait emotional intelligence mediates the dispositional gratitude and subjective well-being in young adults
Authors: Torrelles-Nadal Cristina , Ros-Morente Agnès , Quesada-Pallarès Carla
Published: August 2024

Gratitude has proved to be an enhancer of subjective well-being in previous studies. However, studies that linked the relation between emotional intelligence and its facets when interacting with gratitude, are still limited. In this sense, this study examined the mediating roles of emotional intelligence between gratitude and subjective well-being indicators, by introducing the general factor of emotional intelligence. The first approach to data analysis was to examine the descriptive statistics; the second approach consisted of an Exploratory Structural Equation Modelling, applying also a bifactor analysis. Data was collected from 406 Spanish students, through an online survey that includes the gratitude, trait meta mood scale, satisfaction with life and subjective happiness scale. The mean age of participants was 20.27 years (SD = 4.68), whereas 79.5% were females. The results provided preliminary evidence of the mediation role of the general factor of emotional intelligence between gratitude and subjective well-being, which provided a meaningful insight about the role of trait emotional intelligence. These findings suggested that gratitude promotes emotional intelligence, allowing to an increase in subjective well-being. Nonetheless, there is a need for further research to achieve a better understanding of the role of the emotional intelligence facets between gratitude and subjective well-being.
Beyond age: exploring ultimate attainment in heritage speakers and late L2 learners
Authors: Prela Leonarda , Dąbrowska Ewa , Llompart Miquel
Published: August 2024

According to the Critical Period Hypothesis, successful language learning is optimal during early childhood, whereas language learning outside of this time window is unsuccessful. In this respect, early language acquisition is viewed as convergent and reliable but late acquisition is not. The present study revisits the idea of a critical period by investigating the grammatical attainment of early bilinguals/heritage speakers (HSs), late second/foreign language (L2) learners, and comparable groups of monolinguals by testing Greek-English bilinguals in the two languages they speak by means of a grammaticality judgment task. Our findings show that in English, HSs performed on par with monolinguals, both groups surpassing the late L2 learners, who performed about 2 SDs below the HSs and the monolinguals. In Greek, late L2 learners and monolinguals exhibited comparable performance, contrasting sharply with the HSs’ significantly lower proficiency, which was on average about 5 SDs below the late L2 learners and the monolinguals. Consequently, our results show that the performance gaps between HSs and Greek monolinguals/late L2 learners were more pronounced than the differences between late L2 learners and English monolinguals/HSs, suggesting that the early bilinguals’ success in English may come at the expense of their heritage language (Greek). Furthermore, we observe substantially more individual variation within HSs in their heritage language than within the late L2 learners for their second language. Thus, testing bilinguals in both of their languages allows us to unveil the complexity of grammatical ultimate attainment and prompt a re-thinking of age as the major determining factor of (un)successful attainment.
Opportunities and challenges to implementing mRNA-based vaccines and medicines: lessons from COVID-19
Authors: Iqbal Shehzad M. , Rosen Andrew M. , Edwards Darin , Bolio Ana , Larson Heidi J. , Servin Mariana , Rudowitz Marcy , Carfi Andrea , Ceddia Francesca
Published: August 2024

The messenger RNA (mRNA) platform emerged at the forefront of vaccine development during the COVID-19 pandemic, with two mRNA COVID-19 vaccines being among the first authorized globally. These vaccines were developed rapidly. Informed by decades of laboratory research, and proved to be safe and efficacious tools for mitigating the global impact of the COVID-19 pandemic. The mRNA platform holds promise for a broader medical application beyond COVID-19. Herein, we provide an overview of this platform and describe lessons learned from the COVID-19 pandemic to help formulate strategies toward enhancing uptake of future mRNA-based interventions. We identify several strategies as vital for acceptance of an expanding array of mRNA-based vaccines and therapeutics, including education, accurate and transparent information sharing, targeted engagement campaigns, continued investment in vaccine safety surveillance, inclusion of diverse participant pools in clinical trials, and addressing deep-rooted inequalities in access to healthcare. We present findings from the Global Listening Project (GLP) initiative, which draws on quantitative and qualitative approaches to capture perceptions and experiences during the COVID-19 pandemic to help design concrete action plans for improving societal preparedness for future emergencies. The GLP survey (>70,000 respondents in 70 countries) revealed tremendous disparities across countries and sociodemographic groups regarding willingness to accept novel mRNA vaccines and medicines. The comfort in innovations in mRNA medicines was generally low (35%) and was marginally lower among women (33%). The GLP survey and lessons learnt from the COVID-19 pandemic provide actionable insights into designing effective strategies to enhance uptake of future mRNA-based medicines.
Cross-country adaptation and feasibility of an evidence-based resistance training intervention in the school setting
Authors: Hartman Caroline R. , Lubans David R. , Christiansen Lars B.
Published: August 2024

Background

Physical activity that strengthens muscles and bones at least three times per week are recommended, but few adolescents meet this target. The aim of our study was to adapt and evaluate the feasibility and preliminary efficacy of the Resistance Training for Teens (RT4T) program in Danish lower secondary schools.

Methods

Developed and evaluated in Australia, the aim of RT4T is to provide adolescents with competence, confidence, knowledge, and motivation to participate in resistance training. Translation and adaptation were based on the PRACTIS-guide and involved workshops with physical education teachers. Three 7th-grade classes and three 9th-grade classes were recruited for the feasibility study and followed the program over eight weeks. Participants completed a push-up test, a standing long jump test, and a beep-test before and after the intervention. In addition, they completed a survey about their self-efficacy, motivation, and resistance training competency. Four qualitative interviews were performed with participants and their physical education teachers.

Results

The participating teachers were motivated for the program, but they had difficulties providing students with appropriate feedback. Students were motivated by the equipment, games, and their improvements in fitness, but motivation declined during the program. A total of 57 students completed the physical tests and answered the survey. Resistance training self-efficacy improved significantly, while most other measures improved over time, without reaching significance.

Conclusion

Overall, the RT4T was acceptable and feasible in lower secondary schools in Denmark, but adjustments need to be made to increase the reach and efficacy of the program.
A Normality Criterion for Sharing a Holomorphic Function
Authors: Wang Sheng , Huang Xiaojun
Published: August 2024

In this paper, we scrutinize a collection of meromorphic functions known as normal families, prove the theorem that normal families share a holomorphic function, and present several illustrative counterexamples.
A Review of Intelligent Subway Tunnels Based on Digital Twin Technology
Authors: Zhao Yuhong , Liu Yuhang , Mu Enyi
Published: August 2024

The construction of a new generation of smart cities puts forward higher requirements for the digitization and intelligence of subway tunnel engineering. Digital twin technology has shown great potential in high-fidelity modeling, virtual–real mapping, and decision support based on data analysis, but its research is still in its infancy. To this end, this paper first discusses in depth the inherent complexity and safety risks of subway tunnel construction and emphasizes the significant advantages of digital twin technology compared with traditional technology. Then, by summarizing the existing concepts, this paper proposes a specific explanation of DT applicable to subway tunnel engineering. In order to deeply analyze the potential of digital twin technology in subway tunnel engineering, this paper first conducts a bibliometric analysis and organizes the relevant research directions in recent years based on a visual map. Then, the application of DT in the field of subway tunnel engineering is discussed, including the modeling method of the subway digital twin, intelligent management of the construction process, safety guarantee, operation and maintenance, and resource optimization of traffic facilities in subway stations. Finally, this paper discusses the prospects and gaps of digital twin technology in theoretical and practical applications, aiming to promote the practical application of this technology in subway tunnel engineering. Through the summary and prospect of the existing research, this paper provides a valuable reference for future research directions and practical applications.
Exploring Sustainable Development of New Power Systems under Dual Carbon Goals: Control, Optimization, and Forecasting
Authors: Yang Bo , Duan Jinhang , Liu Zhijian , Jiang Lin
Published: August 2024

In the context of achieving carbon neutrality, the substantial integration of high proportions of renewable energy sources has significantly impacted the dynamic characteristics of power systems, including frequency stability, voltage security, and synchronous stability, thereby posing formidable challenges to the secure and stable operation of power systems [...]
Comparison of Two Generations of Self-Expandable Transcatheter Heart Valves in Nine Surgical Valves: An In Vitro Study
Authors: Sadat Najla , Scharfschwerdt Michael , Ensminger Stephan , Fujita Buntaro
Published: August 2024

(1) Background: This study aimed to analyse the hydrodynamic performance of two generations of self-expanding transcatheter heart valves (THV) as a valve-in-valve (ViV) in different surgical aortic valve (SAV) models under standardised conditions. The nitinol-based Evolut R valve is frequently used in ViV procedures. It is unclear whether its successor, the Evolut PRO, is superior in ViV procedures, particularly considering the previously implanted SAV model. (2) Methods: EvolutTM R 26 mm and EvolutTM PRO 26 mm prostheses were implanted in nine 21 mm labelled size SAV models (Hancock® II, Mosaic® UltraTM, EpicTM Supra, TrifectaTM GT, Perimount®, Perimount® Magna Ease, AvalusTM, IntuityTM, Freestyle®) to analyse their hydrodynamic performance under defined circulatory conditions in a pulse duplicator. (3) Results: Both THVs presented with the lowest effective orifice area (EOA) and highest mean pressure gradient (MPG) inside Hancock® II, whereas THVs in Intuity showed the highest EOA and lowest MPG. Evolut R and Evolut PRO showed significant hydrodynamic differences depending on the SAV. Both THVs performed similarly in porcine valves. Although the Evolut R performed better than Evolut PRO in stented bovine SAVs, the Evolut PRO was superior inside the Intuity. Further, the SAV model design markedly influenced the TAV’s geometric orifice area and pin-wheeling index. (4) Conclusions: These findings show that the Evolut R and Evolut PRO perform differently depending on the previously implanted SAV model. THV selection for treatment of a specific SAV model should consider these results.
Human–Land Coupling Relationship in Lushan National Park and Its Surrounding Areas: From an Integrated Ecological and Social Perspective
Authors: Zhou Zihang , Li Haotian , Li Jie , Lu Yawen , Gao Chi , Yang Diechuan
Published: August 2024

The interaction of human activity in national parks and their surrounding areas with natural landscapes is an important factor in the formulation of strategies for the protection and management of protected areas. From an integrated ecological and social perspective, this study aims to develop a human–land coupling model to reveal the ecological threats of human activities to national park and their surrounding areas under rapid urbanization. We first established a four-quadrant model based on the coupling relationship between human activity intensity (HAI) and the landscape pattern index (LPI). On this basis, we analyzed the spatial coupling characteristics of these indices from 2000 to 2020, preliminarily assessed the human–land relationship in Lushan National Park and its surrounding areas (LNPSA), and then explored the driving factors of the coupling relationship. The results show the following. (1) The proportion of regions with high and extremely high human activity intensity increased from 6.02% to 16.41% over the past two decades. These regions are mainly distributed in the surroundings of Lushan National Park, showing a gradually spreading trend to the core protected area. (2) The surroundings had higher landscape fragmentation, landscape diversity, and total variation in the landscape pattern compared with the core protected area. (3) Vegetation coverage and distance to Lushan have the most significant effect on the human–land coupling relationship in LNPSA, and human activity and natural evolution together shape the characteristics of this relationship in the study area. (4) Utilizing administrative divisions as the fundamental framework, the study area is delineated into four distinct zones based on the results of the human–land coupling analysis—harmonious development zones, stable transformation zones, environmental regulation zones, and risk prevention zones—with tailored optimization strategies proposed for each zone’s characteristics. These findings can facilitate the optimized formulation of schemes for different regions and provide a comprehensive methodology to guide the planning and management of natural protected areas.
Trolox, Ferulic, Sinapic, and Cinnamic Acid Derivatives of Proline and GABA with Antioxidant and/or Anti-Inflammatory Properties
Authors: Papagiouvannis Georgios , Theodosis-Nobelos Panagiotis , Rekka Eleni A.
Published: August 2024

Degenerative conditions, such as neurodegenerative disorders (Alzheimer’s disease (AD), Parkinson’s disease (PD)) and cardiovascular diseases, are complex, multifactorial disorders whose pathophysiology has not been fully elucidated yet. As a result, the available treatment options cannot eliminate these diseases radically, but only alleviate the symptoms. Both inflammatory processes and oxidation are key factors in the development and evolution of neurodegeneration, while acetylcholinesterase inhibitors are the most used therapeutic options against AD. In this work, following the multi-targeting compound approach, we designed and synthesized a series of proline and gamma-aminobutyric acid (GABA) amides with various acidic moieties that possess an antioxidant and/or anti-inflammatory potency. Proline is the pharmacophore of nootropic drugs (e.g., piracetam) used for memory improvement, while GABA is the main inhibitory neurotransmitter in the central nervous system. The designed molecules were subjected to a preliminary screening of their bioactivity in antioxidant and anti-inflammatory assays, as well as against acetylcholinesterase. Most of the synthesized compounds could inhibit lipid peroxidation (IC50 as low as 8 μΜ) and oxidative protein glycation (inhibition of up to 48%) and reduce the 2,2-diphenyl-1-picrylhydrazyl free radical (DPPH). In addition, all of the compounds were moderate inhibitors of lipoxygenase (LOX) (up to 46% at 100 μΜ) and could decrease carrageenan-induced paw edema in rats by up to 55%. Finally, some of the compounds were moderate acetylcholinesterase inhibitors (IC50 as low as 219 μΜ). The results confirmed the design rationale, indicating that the compounds could be further optimized as multi-targeting molecules directed against degenerative conditions.
The Geochemical Characteristics and Genesis Mechanisms of the Zaozigou Geothermal Field
Authors: Wang Yuang , Li Baozhu , Chen Aibing
Published: August 2024

Geothermal resources have become one of the crucial clean energy sources worldwide. The Gansu Province is renowned in China for its abundant geothermal resources. The Zaozigou area features prominent geothermal outcrops, indicating untapped geothermal potential. However, the level of geothermal resource development in this region remains low, coupled with a lack of comprehensive research on its hydrochemical characteristics and formation mechanisms. This study conducted an in-depth hydrochemical analysis of six geothermal water groups and two surface water groups within the collection area, along with collecting hydrogen and oxygen isotope data from nine geothermal water sources. Piper trigram and Na-K-Mg diagram were utilized to investigate the origin of the subsurface hot water. Various analyses, including characteristic coefficients, correlation analysis, hydrochemical types, recharge elevation, reservoir temperature, and circulation depth, were conducted on the geothermal water. The study proposes a preliminary conceptual model of the Zaozigou geothermal system, providing a theoretical basis for the rational utilization of geothermal resources and promoting sustainable resources.
Methyl Red Adsorption from Aqueous Solution Using Rumex Abyssinicus-Derived Biochar: Studies of Kinetics and Isotherm
Authors: Teweldebrihan Meseret Dawit , Dinka Megersa Olumana
Published: August 2024

This work focused on the decolorization of methyl red (MR) from an aqueous solution utilizing Rumex abyssinicus-derived biochar (RAB). RAB was prepared to involve unit operations such as size reduction, drying, and carbonization. The pyrolysis of the precursor material was carried out at a temperature of 500 °C for two hours. After that, the prepared RAB was characterized by the pH point of zero charge (pHpzc), the Brunauer–Emmett–Teller (BET) method, Scanning Electron Microscopy (SEM) and Fourier-Transform Infrared (FTIR) spectroscopy. On the other hand, a batch adsorption experiment of MR removal onto RAB was conducted, considering four operating parameters: pH, contact time, adsorbent dose, and initial dye concentration. The characterization of the adsorbent material revealed a porous and heterogeneous surface morphology during SEM, a specific surface area of 45.8 m2/g during the BET method, the presence of various functional groups during FTIR, and a pHpzc of 6.2. The batch adsorption experiment analysis results revealed that a maximum removal efficiency of 99.2% was attained at an optimum working condition of pH 6, contact time of 40 min, initial dye concentration of 70 mg/L and adsorbent dosage of 0.2 g/100 mL. Furthermore, Freundlich isotherm (R2 = 0.99) and pseudo-second-order kinetics (R2 = 0.99) models confirmed the heterogeneous surface interaction and chemisorption nature. Generally, this study highlighted that RAB could be a potential adsorbent for the detoxification of MR-containing industrial effluents.
análise das produções bibliográficas envolvendo a gamificação aliada ao Software GeoGebra para o ensino de Funções do Segundo Grau
Authors: Henrique Dias Iasmim , Scortegagna Liamara
Published: August 2024

Este trabalho tem por objetivo mapear as produções acadêmicas, identificando e analisando os trabalhos que debatem o uso da Gamificação aliada ao Software GeoGebra para o ensino de Funções do Segundo Grau. Utilizou-se as bases de dados do Portal de Periódico da Capes, BDTD e Google Scholar onde, após todos os critérios de inclusão e exclusão e leitura preliminar, discorreu-se sobre 06 (seis) trabalhos que possuíam aderência com a temática pesquisada e com o intuito de responder a seguinte questão: “Quais as contribuições da Gamificação aplicada no software GeoGebra, para o processo de aprendizagem de Funções do Segundo Grau?”. O resultado revelou uma lacuna na questão de investigação, visto que os trabalhos encontrados tratam da temática para a formação de professores e não para a aprendizagem do educando. Ainda, a gamificação no GeoGebra se mostrou um tema pouco debatido, mas relevante na busca por tornar o software mais atrativo e recepitivo.
THE OPTIMAL REPAIR PERIODS DETERMING FOR ENERGY EQUIPMENT OF TPP
Authors: Amosov Nikolay , Markina Mariya
Published: August 2024

Functional elements, detailes and energy equipment systems of thermal power plants (TPP) are subject to wastage.Main reasons of wastage are different operational modes, critical parameteres usage, fatigue of the equipment. One of the most popular problems for TPP is a failure which has random character. Consequently repairs have stochastic features. Listed data show a necessaty to develop a methodology for deremining optimal repair periods. The aim of this article to develop this methodology. The basis of this methodology is mathematical apparatus of reliability theory, methods of mathematical statistics usage and computer technologies usage. Energy systems operation is presented as sequence of uptime and downtime periods. Also availability factor and conditions for the average duration of emergency repairs are made. Using nonlinear regression analysis demonstrates character of external conditions influence at the equipment, what presents developed mathematical model.
MULTICRITERIA ASSESSMENT OF TURBINE OPERATION EFFICIENCY
Authors: Gavrilova Anna , Sagitova Lyajsan , Shemetov Maksim , Antonova Angelina
Published: August 2024

The article provides a systematic analysis of the operating efficiency of the main technological equipment of a combined heat and power plant (CHP) based on a study of real statistical data obtained during testing. A set of partial efficiency indicators, collapsing into a global criterion, has been determined. An integral assessment of the potential of generating equipment of energy enterprises was carried out. The criterion of comparative efficiency makes it possible to determine the optimal characteristics and operating modes of power plants of various energy facilities. Based on the Data Envelopment Analysis (DEA) methodology, a methodology for multi-criteria comparative assessment of the integrated efficiency of turbine units in various modes has been developed and proposed. In general, the analysis showed that the proposed methodology allows for both qualitative and quantitative multi-criteria assessment of the generalized operating efficiency of a turbine unit in various states. The use of a multi-criteria methodology for assessing the efficiency of turbine units makes it possible to analyze the functioning and select optimal operating modes, and develop recommendations for optimizing the modes of the main equipment. It also leads to: improving the thermodynamic cycles of thermal power plants, increasing the coefficient of performance (efficiency) of the generating equipment of existing thermal power plants, increasing the efficiency of using energy and material resources, reducing the cost of produced electrical and thermal energy.
PHYSICAL MODELING OF ABNORMAL MODES IN ELECTRICAL NETWORKS WITH VOLTAGE 6-35 KV
Authors: Novikov Aleksey , Zlobin Alexander , Khoroshinina Elena
Published: August 2024

The article is devoted to the features of physical modeling of single-phase earth faults in 6-35 kV networks in laboratory conditions. Such damage is not associated with the occurrence of short circuit currents. The ground fault currents flowing at the fault site are tens of times less than the load currents. Therefore, traditional current protection, such as current cut-off or overcurrent protection, is unsuitable for detecting such faults. The insulation condition is monitored using voltage transformers, in which one of the secondary windings is connected in an open delta. When a ground fault occurs, the resulting asymmetrical mode causes the appearance of a zero-sequence voltage 3·U ̇_0, the magnitude of which depends on the resistance at the location of the fault. A voltage relay connected to this winding completes the signal circuits. The low-voltage windings of power transformers are connected in a triangle, so the line voltages during single-phase ground faults remain unchanged, and the consumer can receive power. Network operation in asymmetrical mode is limited to two hours due to overloading of the insulation of healthy phases, the possible occurrence of an intermittent arc and overheating of electric motor rotors.
MICROCLIMATE PROBLEMS IN THE MAIN BUILDING AT IVANOVO CHPP-2
Authors: Bukhmirov Vyacheslav , Svetushkov Ilya
Published: August 2024

The problems of the microclimate in the production premises lead to an increase in energy costs for the station's own needs and a deterioration in the well-being of the maintenance staff. To avoid this, it is first necessary to analyze the variations of the main parameters. Therefore, the main building (boiler and turbine shop) was chosen for the study Ivanovo CHPP-2. The pilot study was conducted twice a month between 2020 and 2023. As a result of the research, experimental data on the main indicators of the microclimate of the main building of thermal power plants were obtained. The microclimate parameters were measured at the main operating levels in the turbine and boiler rooms during warm and cold periods of the year. The analysis of the obtained data on the microclimate revealed deviations of a number of parameters from the normal values such as temperature, humidity and concentration of volatile substances. The total temperature deviation from the norm in the boiler turbine shop was 15 °C in the warm period, and 7.2 °C in the cold period. Humidity differed by 7.12% in the warm period and by 12.26 °C in the cold period. The maximum deviation of the concentration of volatile organic substances in the air was 6.87 mg/m3.
APPLICATION OF RECOOPERATIVE VENTILATION SYSTEM IN INDIVIDUAL DWELLING
Authors: Larin Bogdan
Published: August 2024

The ventilation system in an individual dwelling house with an attic is considered. Two autonomous ventilation shafts are installed in the house, which provide air supply and outflow. The system provides prevention of cold air access to the room, mechanical protection of the supply air. Fresh air from the street - heated or cooled - is constantly added to the recuperative system, which allows for significant savings in heating or air conditioning. Thus, the use of recuperators in the ventilation system provides a comfortable microclimate and air quality for life, helps to naturally heat the incoming air to a comfortable temperature, and thus save on heating costs.
EVALUATION OF LOWERING THE VALUE OF INRUSH CURRENTS BY SOFT-STARTING A DC ELECTRIC DRIVE BY MEANS OF THE SHIP-DPT SYSTEM IN ELECTRIC TRANSPORT SYSTEMS AT A CONSTANT LOAD MOMENT
Authors: Medvedev Boris
Published: August 2024

The article considers the smooth start of a DC motor as an effective way to reduce the value of starting currents in conditions of constant load on the motor. The effect of engine acceleration on the magnitude of starting currents is demonstrated. The article also demonstrates the effect of negative feedback on the speed of the engine on the appearance of the transition curve of the engine. It is concluded that an increase in engine acceleration leads to an increase in the inrush current. And also that the use of negative feedback in terms of speed can significantly reduce the amount of inrush current. It is proved that the control system described in the article qualitatively copes with the requirements of bringing the engine to the rated operating mode and ensuring the permissible value of the inrush current overload.
CLASSIFICATION OF TRANSFORMER SUBSTATIONS
Authors: Shcheglovitova Elena , Zotova Anastasia
Published: August 2024

The transfer of electrical energy from the power station to the consumer over long distances is possible by changing the voltage level. An integral part in the operation of electrical networks is an electromagnetic device that changes the voltage level - a power transformer. The most important is voltage transformation, first in order to increase the voltage coming from the generator buses of a power plant to reduce power losses during long-distance transmission, and then lower it to the level required by the consumer's power receiving devices. The article presents the variety of transformer substations. The authors propose a classification of transformer substations according to a number of characteristics. The article reflects the methods of connecting substations to supply lines, their functional features by type, features of placement and purpose. The layout components common to all transformer substations are presented - high-voltage switchgear, the transformer itself and low-voltage switchgear. The study also used data from the experience of operating electric grid organizations in the northern regions of the Russian Federation, common in the market of electrical devices of block-type complete transformer substations. In accordance with which the most vulnerable spots of modern transformer substations are indicated.
Persistent pollutants in marine organisms: assessment of the state of the Black Sea environment
Authors:   Department of Chemistry, Faculty of Pharmacy, Medical University - Varna, 55 Marin Drinov Str., Varna, Bulgaria, Georgieva S. K. , Peteva Zl. ,   Department of Chemistry, Faculty of Pharmacy, Medical University - Varna, 55 Marin Drinov Str., Varna, Bulgaria, Valkova S. ,   Department of Chemistry, Faculty of Pharmacy, Medical University - Varna, 55 Marin Drinov Str., Varna, Bulgaria
Published: August 2024

In the last decades, the residues of persistent pollutants such as organochlorine pesticides and polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in marine ecosystems and continue to bioaccumulate in animal tissues. The present study investigated the presence of pollutants in biota with the aim to assess the current environmental state of the Black Sea using benthic fish species as sentinel organisms. The biota samples: goby (Neogobius melanostomus), grey mullet (Mugil cephalus) and turbot (Psetta maxima maeotica) were collected from different sites along the Bulgarian Black Sea coast in the period 2021 – 2022. The concentrations of 13 PAHs and organochlorine pesticides such as DDTs and its metabolites, hexachlorocyclohexane and its isomers (HCHs), hexachlorobenzene (HCB) and hexachlorobutadiene (HCBD) were determined in fish tissues by simultaneous extraction of persistent compounds in an accelerated solvent extractor (ASE) and were detected by gas chromatography with mass spectrometry (GC-MS). The highest levels of PAHs in fish were found in goby samples: 14.2 ng/g ww (wet weight). The results showed that low-molecular weight (LMW) PAHs (3 and 4 aromatic rings) were predominant accounting 94% of total PAH levels, suggesting petrogenic origin of pollution. Benzo(a)pyrene was not detected in fish samples from the Bulgarian Black Sea coast. Lindane and other HCHs isomers have very low concentrations in all samples investigated. DDT is present mainly in the form of its metabolites p,p’- DDE and p,p’- DDD, suggesting contamination in the past. The HCB and HCBD levels in the fish species did not exceed the EQS of the Directive 2013/39/ EU. These results confirm that the persistent organic pollutants continue to be present in the Black Sea marine environment.
The modification of [18F]FDG for further click reactions
Authors:   UMHAT ", Simeonova G. V. ,   St. Marina",   , Department of Nuclear Medicine, 1 Hristo Smirnenski Blvd., Varna, Bulgaria,   Sofia University St. Kliment Ohridski, Faculty of Chemistry and Pharmacy, Department of Analytical Chemistry, 1 James Bourchier Str, Sofia. Bulgaria, Todorov B. R. ,   Sofia University St. Kliment Ohridski, Faculty of Chemistry and Pharmacy, Department of Analytical Chemistry, 1 James Bourchier Str, Sofia. Bulgaria
Published: August 2024

The synthesis of new fluorinated PET radiopharmaceuticals is facilitated by various strategies for 18F labeling reactions. [18F]FDG, as a basic PET radiopharmaceutical (glucose analog), can be used as a building block for indirect radiofluorination under mild reaction conditions, due to the presence of a carbonyl group where chemoselective formation of an oxime bond can take place for conjugation with target moieties. The glycosylation is one of the used modification strategies that can increase the hydrophilicity of the radiotracer, and shorten the period between injection and imaging. Also, glycosylation of biomolecules such as peptides or proteins can improve in vivo pharmacokinetics and blood stability. We have developed a procedure for modification of [ 18F]FDG with bifunctional tetrazine derivatives, by oxime bond formation and all experiments were done with standard clinical equipments. For this purpose, [18F]FDG was produced using a biomedical baby-cyclotron at the Nuclear Medicine Clinic at the University Hospital "St. Marina" – Varna. Successful modification with [18F]FDG was achieved at a temperature of 70-75oC, in a slightly acidic environment (pH= 4-4.2), in the presence of a p-diaminobenzene catalyst for 25-30 minutes. TLC chromatography was used as a fast and available in clinic method to monitor the synthesis process. This is a prerequisite for the development of new PET radiopharmaceuticals and for the refinement of diagnostics and therapy in nuclear medicine
Lipid composition and investigation of the physicochemical characteristics of higholeic sunflower oil at different temperatures
Authors:   University of Food Technologies, Department of Analytical and Physical Chemistry, 26 Maritza Blvd., 4002 Plovdiv, Bulgaria, Gandova V. D. , Teneva O. T. ,   University of Plovdiv “Paisii Hilendarski”, Department of Chemical Technology, 24 Tzar Asen Str., 4000 Plovdiv, Bulgaria, Petkova Z. Y. ,   University of Plovdiv “Paisii Hilendarski”, Department of Chemical Technology, 24 Tzar Asen Str., 4000 Plovdiv, Bulgaria, Iliev I. Z. ,   University of Plovdiv “Paisii Hilendarski”, Department of Chemical Technology, 24 Tzar Asen Str., 4000 Plovdiv, Bulgaria,   University of Food Technologies, Technological Faculty, Department of Technology of Tobacco, Sugar, Vegetable and Essential oils, 26 Maritza Blvd., 4002, Plovdiv, Bulgaria, Stoyanova A. S. ,   University of Food Technologies, Technological Faculty, Department of Technology of Tobacco, Sugar, Vegetable and Essential oils, 26 Maritza Blvd., 4002, Plovdiv, Bulgaria
Published: August 2024

High-oleic sunflower oil is characterized by high stability, and hence high quality. The aim of the present work is to determine the chemical composition of the lipid fraction (fatty acids, unsaponifiable matter, tocopherols and sterols) and some physicochemical parameters (density, surface tension, dynamic and kinematic viscosity) of high-oleic sunflower oil. The main fatty acids in the investigated oil were: oleic (77.9%), linoleic (11.5%), palmitic (5.0%), and stearic (3.3%). ß-Sitosterol (79.7%) and α-tocopherol (100%) were the major components in the sterol and tocopherol fractions of the oil. The variation of the physicochemical parameters was followed at seven temperatures (20, 30, 40, 50, 60, 70, and 80 °C). With an increase in temperature, all parameters decreased and a good linear dependence was observed – density (from 0.868 g/ml to 0.847 g/ml), surface tension (from 29.775 mN/m to 12.461 mN/m), dynamic viscosity (from 44.401 mPa/s to 40.067 mPa/s), and kinematic viscosity (from 51.148 mm2 /s to 47.268 mm2 /s). The present results are a basis for future research on the incorporation of high-oleic sunflower oil into food products with improved functional characteristics.