bluuebunny/crossref_metadata_2025 huggingface dataset:
Bioactive Compounds and Potential Health Benefits through Cosmetic Applications of Cherry Stem Extract
Authors: García-Villegas Abigail , Fernández-Ochoa Álvaro , Alañón María Elena , Rojas-García Alejandro , Arráez-Román David , Cádiz-Gurrea María de la Luz , Segura-Carretero Antonio
Published: March 2024

Cherry stems, prized in traditional medicine for their potent antioxidant and anti-inflammatory properties, derive their efficacy from abundant polyphenols and anthocyanins. This makes them an ideal option for addressing skin aging and diseases. This study aimed to assess the antioxidant and anti-inflammatory effects of cherry stem extract for potential skincare use. To this end, the extract was first comprehensively characterized by HPLC-ESI-qTOF-MS. The extract’s total phenolic content (TPC), antioxidant capacity, radical scavenging efficiency, and its ability to inhibit enzymes related to skin aging were determined. A total of 146 compounds were annotated in the cherry stem extract. The extract effectively fought against NO· and HOCl radicals with IC50 values of 2.32 and 5.4 mg/L. Additionally, it inhibited HYALase, collagenase, and XOD enzymes with IC50 values of 7.39, 111.92, and 10 mg/L, respectively. Based on the promising results that were obtained, the extract was subsequently gently integrated into a cosmetic gel at different concentrations and subjected to further stability evaluations. The accelerated stability was assessed through temperature ramping, heating-cooling cycles, and centrifugation, while the long-term stability was evaluated by storing the formulations under light and dark conditions for three months. The gel formulation enriched with cherry stem extract exhibited good stability and compatibility for topical application. Cherry stem extract may be a valuable ingredient for creating beneficial skincare cosmeceuticals.
Assessment of Red Blood Cell Aggregation in Preeclampsia by Microfluidic Image Flow Analysis—Impact of Oxidative Stress on Disease Severity
Authors: Alexandrova-Watanabe Anika , Abadjieva Emilia , Giosheva Ina , Langari Ariana , Tiankov Tihomir , Gartchev Emil , Komsa-Penkova Regina , Todinova Svetla
Published: March 2024

Preeclampsia (PE) is a hypertensive disease characterized by proteinuria, endothelial dysfunction, and placental hypoxia. Reduced placental blood flow causes changes in red blood cell (RBC) rheological characteristics. Herein, we used microfluidics techniques and new image flow analysis to evaluate RBC aggregation in preeclamptic and normotensive pregnant women. The results demonstrate that RBC aggregation depends on the disease severity and was higher in patients with preterm birth and low birth weight. The RBC aggregation indices (EAI) at low shear rates were higher for non-severe (0.107 ± 0.01) and severe PE (0.149 ± 0.05) versus controls (0.085 ± 0.01; p < 0.05). The significantly more undispersed RBC aggregates were found at high shear rates for non-severe (18.1 ± 5.5) and severe PE (25.7 ± 5.8) versus controls (14.4 ± 4.1; p < 0.05). The model experiment with in-vitro-induced oxidative stress in RBCs demonstrated that the elevated aggregation in PE RBCs can be partially due to the effect of oxidation. The results revealed that RBCs from PE patients become significantly more adhesive, forming large, branched aggregates at a low shear rate. Significantly more undispersed RBC aggregates at high shear rates indicate the formation of stable RBC clusters, drastically more pronounced in patients with severe PE. Our findings demonstrate that altered RBC aggregation contributes to preeclampsia severity.
Targeting N-Methyl-d-Aspartate Receptors in Neurodegenerative Diseases
Authors: Carles Allison , Freyssin Aline , Perin-Dureau Florent , Rubinstenn Gilles , Maurice Tangui
Published: March 2024

N-methyl-d-aspartate receptors (NMDARs) are the main class of ionotropic receptors for the excitatory neurotransmitter glutamate. They play a crucial role in the permeability of Ca2+ ions and excitatory neurotransmission in the brain. Being heteromeric receptors, they are composed of several subunits, including two obligatory GluN1 subunits (eight splice variants) and regulatory GluN2 (GluN2A~D) or GluN3 (GluN3A~B) subunits. Widely distributed in the brain, they regulate other neurotransmission systems and are therefore involved in essential functions such as synaptic transmission, learning and memory, plasticity, and excitotoxicity. The present review will detail the structure, composition, and localization of NMDARs, their role and regulation at the glutamatergic synapse, and their impact on cognitive processes and in neurodegenerative diseases (Alzheimer’s, Huntington’s, and Parkinson’s disease). The pharmacology of different NMDAR antagonists and their therapeutic potentialities will be presented. In particular, a focus will be given on fluoroethylnormemantine (FENM), an investigational drug with very promising development as a neuroprotective agent in Alzheimer’s disease, in complement to its reported efficacy as a tomography radiotracer for NMDARs and an anxiolytic drug in post-traumatic stress disorder.
Comparative Transcriptomic Analysis Revealing the Potential Mechanisms of Erythritol-Caused Mortality and Oviposition Inhibition in Drosophila melanogaster
Authors: Li Lei , Duo Hongrui , Zhang Xiaoxi , Gong Huiming , Li Bo , Hao Youjin
Published: March 2024

Erythritol has shown excellent insecticidal performance against a wide range of insect species, but the molecular mechanism by which it causes insect mortality and sterility is not fully understood. The mortality and sterility of Drosophila melanogaster were assessed after feeding with 1M erythritol for 72 h and 96 h, and gene expression profiles were further compared through RNA sequencing. Enrichment analysis of GO and KEGG revealed that expressions of the adipokinetic hormone gene (Akh), amylase gene (Amyrel), α-glucosidase gene (Mal-B1/2, Mal-A1-4, Mal-A7/8), and triglyceride lipase gene (Bmm) were significantly up-regulated, while insulin-like peptide genes (Dilp2, Dilp3 and Dilp5) were dramatically down-regulated. Seventeen genes associated with eggshell assembly, including Dec-1 (down 315-fold), Vm26Ab (down 2014-fold) and Vm34Ca (down 6034-fold), were significantly down-regulated or even showed no expression. However, there were no significant differences in the expression of three diuretic hormone genes (DH44, DH31, CAPA) and eight aquaporin genes (Drip, Big brain, AQP, Eglp1, Eglp2, Eglp3, Eglp4 and Prip) involved in osmolality regulation (all p value > 0.05). We concluded that erythritol, a competitive inhibitor of α-glucosidase, severely reduced substrates and enzyme binding, inhibiting effective carbohydrate hydrolysis in the midgut and eventually causing death due to energy deprivation. It was clear that Drosophila melanogaster did not die from the osmolality of the hemolymph. Our findings elucidate the molecular mechanism underlying the mortality and sterility in Drosophila melanogaster induced by erythritol feeding. It also provides an important theoretical basis for the application of erythritol as an environmentally friendly pesticide.
The Bee Gut Microbiota: Bridging Infective Agents Potential in the One Health Context
Authors: Tilocca Bruno , Greco Viviana , Piras Cristian , Ceniti Carlotta , Paonessa Mariachiara , Musella Vincenzo , Bava Roberto , Palma Ernesto , Morittu Valeria Maria , Spina Anna Antonella , Castagna Fabio , Urbani Andrea , Britti Domenico , Roncada Paola
Published: March 2024

The bee gut microbiota plays an important role in the services the bees pay to the environment, humans and animals. Alongside, gut-associated microorganisms are vehiculated between apparently remote habitats, promoting microbial heterogeneity of the visited microcosms and the transfer of the microbial genetic elements. To date, no metaproteomics studies dealing with the functional bee microbiota are available. Here, we employ a metaproteomics approach to explore a fraction of the bacterial, fungal, and unicellular parasites inhabiting the bee gut. The bacterial community portrays a dynamic composition, accounting for specimens of human and animal concern. Their functional features highlight the vehiculation of virulence and antimicrobial resistance traits. The fungal and unicellular parasite fractions include environment- and animal-related specimens, whose metabolic activities support the spatial spreading of functional features. Host proteome depicts the major bee physiological activities, supporting the metaproteomics strategy for the simultaneous study of multiple microbial specimens and their host-crosstalks. Altogether, the present study provides a better definition of the structure and function of the bee gut microbiota, highlighting its impact in a variety of strategies aimed at improving/overcoming several current hot topic issues such as antimicrobial resistance, environmental pollution and the promotion of environmental health.
QISS: Quantum-Enhanced Sustainable Security Incident Handling in the IoT
Authors: Blanco Carlos , Santos-Olmo Antonio , Sánchez Luis Enrique
Published: March 2024

As the Internet of Things (IoT) becomes more integral across diverse sectors, including healthcare, energy provision and industrial automation, the exposure to cyber vulnerabilities and potential attacks increases accordingly. Facing these challenges, the essential function of an Information Security Management System (ISMS) in safeguarding vital information assets comes to the fore. Within this framework, risk management is key, tasked with the responsibility of adequately restoring the system in the event of a cybersecurity incident and evaluating potential response options. To achieve this, the ISMS must evaluate what is the best response. The time to implement a course of action must be considered, as the period required to restore the ISMS is a crucial factor. However, in an environmentally conscious world, the sustainability dimension should also be considered to choose more sustainable responses. This paper marks a notable advancement in the fields of risk management and incident response, integrating security measures with the wider goals of sustainability and corporate responsibility. It introduces a strategy for handling cybersecurity incidents that considers both the response time and sustainability. This approach provides the flexibility to prioritize either the response time, sustainability or a balanced mix of both, according to specific preferences, and subsequently identifies the most suitable actions to re-secure the system. Employing a quantum methodology, it guarantees reliable and consistent response times, independent of the incident volume. The practical application of this novel method through our framework, MARISMA, is demonstrated in real-world scenarios, underscoring its efficacy and significance in the contemporary landscape of risk management.
Pupal and Adult Experience Affect Adult Response to Food Odour Components in the Flower-Visiting Butterfly Tirumala limniace
Authors: Li Chengzhe , Wang Hua , Bian Fangyuan , Yao Jun , Shi Lei , Chen Xiaoming
Published: March 2024

Butterflies have the ability to learn to associate olfactory information with abundant food sources during foraging. How the co-occurrence of both food and food odours affects the learning behaviour of adults and whether butterflies perceive the odour of their surroundings and develop a preference for that odour during the pupal stage have rarely been tested. We examined the effect of experience with food odour components (α-pinene and ethyl acetate) during the pupal and adult stages on the foraging behaviour of the flower-visiting butterfly Tirumala limniace. We found that α-pinene exposure during the pupal stage changed the foraging preference of newly emerged adults. T. limniace exhibits olfactory learning in the adult stage, and adult learning may influence their previous pupal memory. Moreover, adults’ odour preference did not continue to increase over multiple training times. The learning ability of adults for floral odours (α-pinene) was greater than that for non-floral odours (ethyl acetate). In contrast to previous studies, we found that males learned odours more efficiently than females did. This could be attributed to differences in antennal sensilla, affecting sensitivity to compounds and nectar demand between males and females. Our study provides further insight into how olfactory learning helps flower-visiting butterflies use food odours to forage better.
A Cross-Sectional Study of Factors Predicting the Duration of the Efficacy of Viscosupplementation in Knee Osteoarthritis
Authors: Rapp Charles , Boudif Feriel , Bourgoin Charlotte , Lohse Anne , Conrozier Thierry
Published: March 2024

Background: An advanced radiological stage and obesity are predictive of poorer and shorter responses to viscosupplementation in patients with knee osteoarthritis (OA). Very little is known regarding the impact of other factors such as sport practice, comorbidities, or anatomical features of OA. Methods: This study aimed to investigate patients’ and OA characteristics associated with the duration of the effectiveness (DE) of viscosupplementation in patients with knee OA. It was a cross-sectional, single-centre clinical trial in patients with knee OA treated with intra-articular (IA) hyaluronic acid (HA) injection(s) within the previous 3 years. The investigators collected data regarding demographic and radiographic features (Kellgren–Lawrence grade and involved knee compartments), dosing regimen (single or repeat injections), the presence and volume of joint effusion, previous or concomitant IA corticosteroid injection, the number of previous viscosupplementations, and comorbidities. Patients completed a questionnaire including the self-assessment of DE (the number of weeks during which viscosupplementation was effective on symptoms), the activity level (sedentary, active, or athletic), and the level of sport activity (light, moderate, or intensive). Predictors of the DE were studied in bivariate and multivariate analyses. Results: In total, 105 patients (149 knees) were analysed (62% women, mean age 66.1 ± 13.2 years, mean BMI 27.5 ± 7.5 kg/m2). The mean DE was 48.2 ± 24.8 weeks. In bivariate analysis, the predictors of a shorter DE were BMI > 27.5 kg/m2, more than three previous viscosupplementations, Kellgren–Lawrence grade 4, sedentary patients, and multicompartmental involvement. In the multivariate analysis, four independent factors remained associated with a shorter DE: BMI > 27.5 kg/m2, multicompartmental knee involvement, number of viscosupplementations >3, and sedentary lifestyle. A statistically significant association between a longer DE and arterial hypertension was found, suggesting a beneficial effect of certain antihypertensive medications. Conclusions: This study confirms that being overweight significantly reduces the duration of the effectiveness of viscosupplementation. It also shows that viscosupplementation is more lastingly effective in unicompartmental OA and among active or athletic patients. The duration of effectiveness decreases when the treatment is repeated more than three times.
The Epidemiology of Shoulder Injuries in Water Polo Players: A Monocentric Descriptive Study on Clinical and Radiological Presentation
Authors: Minelli Marco , Longo Umile Giuseppe , Ranieri Riccardo , Pascucci Federico , Giunti Filippo , Conti Marco , Catellani Francesco , Castagna Alessandro
Published: March 2024

Water polo players’ shoulders are exposed to repeated overhead and throwing motions as well as direct and indirect traumas. Shoulder injuries account for over half of all injuries sustained by water polo players. This is a monocentric descriptive epidemiological study on the clinical and radiological presentation of a consecutive series of water polo players from January 2002 to September 2022. All patients underwent clinical and physical examinations and an MRI arthrogram. A total of 92 water polo players were included in this study. Fifty-three patients (57.6%) reported at least one previous shoulder instability episode; 100% of patients in this group were diagnosed with a capsulolabral complex lesion, and 88.7% of these players complained of subjective symptoms of shoulder instability (RR: 4.4). A total of 39 out of 92 patients (42.4%) did not report previous shoulder dislocation episodes; the mean age at presentation in this group was significantly higher than the mean age of the patients who experienced previous instability episodes (p < 0.01), and the throwing arm was affected in 79.5% of patients (RR = 1.41).
Mitigating Crack Propagation in Hybrid Composites: An Experimental and Computational Study
Authors: Ayyagari Suma , Al-Haik Marwan
Published: March 2024

The exceptional properties of carbon nanotubes (CNTs) make them ideal nanofillers for various composite materials. In carbon fiber-reinforced polymer (CFRP) composites. CNTs can be grown on the carbon fiber surface to act as a third interface between the fiber and the matrix. However, it was established that the uncontrolled random growth of CNTs could exacerbate delamination in composite structures. Thick nanofiller films could hinder the epoxy from seeping into the carbon fiber, resulting in insufficient interlaminar strength. Hence, the density and distribution of nanofillers play a crucial role in determining the hybrid composite fracture mechanisms. In this investigation, CNTs were grown using the low-temperature technique into specific patterns over carbon fibers to discern their derived composites’ fracture properties. The composite fracture energy release was probed using a double cantilever beam (DCB) test setup and digital image correlation (DIC) to monitor interlaminar crack propagation. A standard finite element simulation model based on the cohesive zone method (CZM) was also utilized to delineate fracture behaviors of the various composite configurations. Results conclude that a coarser pattern of CNT growth enhances resistance to crack propagation, thus improving the interlaminar fracture toughness of a composite structure.
Deciphering Paleoceanographic Shifts Inferred from the Foraminiferal Record of the Western Svalbard Slope (Bellsund Drift) over the Past Century
Authors: Gamboa Sojo Viviana M. , Morigi Caterina , Langone Leonardo , Lucchi Renata G.
Published: March 2024

The objective of this study was to reconstruct the last century’s climatic oscillations in the Arctic region around the Fram Strait using high-resolution analysis of foraminiferal assemblages as proxies for surface and deep-water mass properties. In this area, warm Atlantic water masses are advected to the Arctic Ocean through the West Spitsbergen Current, representing the northernmost tip of the Global Thermohaline Circulation. The interaction between the cold Arctic and the warm Atlantic water masses significantly influences the entire foraminiferal community. Planktic species such as Neogloboquadrina pachyderma and Turborotalita quinqueloba are respectively used as indicators of cold Arctic water and warm Atlantic water masses. Among the main benthic species, Cibicidoides wuellerstorfi, Epistominella exigua, and Oridorsalis tener stand out, serving as proxies for the bottom water mass current velocity and paleoproductivity. The paleoenvironmental reconstruction obtained with the foraminiferal assemblages, together with data from satellite monitoring of the sea ice extent and the long-term record of the annual temperature of the West Spitsbergen Current measured over the last 50 years, support the evidence of a progressively rising heat influx into the Arctic Ocean due to an increasing Atlantic water inflow, forcing the consequent decay of the sea ice extent.
Potential Activity of Micafungin and Amphotericin B Co-Encapsulated in Nanoemulsion against Systemic Candida auris Infection in a Mice Model
Authors: Marena Gabriel Davi , Carvalho Gabriela Corrêa , Ruiz-Gaitán Alba , Onisto Giovana Scaramal , Bugalho Beatriz Chiari Manzini , Genezini Letícia Maria Valente , Santos Maíra Oliveira Dos , Blanco Ana Lígia , Chorilli Marlus , Bauab Tais Maria
Published: March 2024

The Candida auris species is a multidrug-resistant yeast capable of causing systemic and lethal infections. Its virulence and increase in outbreaks are a global concern, especially in hospitals where outbreaks are more recurrent. In many cases, monotherapy is not effective, and drug combinations are opted for. However, resistance to antifungals has increased over the years. In view of this, nanoemulsions (NEs) may represent a nanotechnology strategy in the development of new therapeutic alternatives. Therefore, this study developed a co-encapsulated nanoemulsion with amphotericin B (AmB) and micafungin (MICA) (NEMA) for the control of infections caused by C. auris. NEs were developed in previous studies. Briefly, the NEs were composed of a mixture of 10% sunflower oil and cholesterol as the oil phase (5:1), 10% Polyoxyethylene (20) cetyl ether (Brij® 58) and soy phosphatidylcholine as surfactant/co-surfactant (2:1), and 80% PBS as the aqueous phase. The in vivo assay used BALB/c mice weighing between 25 and 28 g that were immunosuppressed (CEUA/FCF/CAr n° 29/2021) and infected with Candida auris CDC B11903. The in vivo results show the surprising potentiate of the antifungal activity of the co-encapsulated drugs in NE, preventing yeast from causing infection in the lung and thymus. Biochemical assays showed a higher concentration of liver and kidney enzymes under treatment with AmB and MICAmB. In conclusion, this combination of drugs to combat the infection caused by C. auris can be considered an efficient therapeutic option, and nanoemulsions contribute to therapeutic potentiate, proving to be a promising new alternative.
Non-Union Treatment in the Foot, Ankle, and Lower Leg: A Multicenter Retrospective Study Comparing Conventional Treatment with the Human Allogeneic Cortical Bone Screw (Shark Screw®)
Authors: Labmayr Viktor , Huber Elisabeth , Wenzel-Schwarz Florian , Holweg Patrick , Ornig Martin , Jakob Gerd , Palle Wolfgang , Borchert Gudrun H. , Pastl Klaus
Published: March 2024

Addressing non-unions involves stabilizing the affected area through osteosynthesis and improving bone biology using bone grafts. However, there is no consensus on the optimal treatment method. This study aims to compare outcomes of non-union surgery using conventional treatment methods (metal hardware ± graft) versus osteosynthesis with the human allogeneic cortical bone screw (Shark Screw®) alone or in combination with a metallic plate. Thirty-four patients underwent conventional treatment, while twenty-eight cases received one or more Shark Screws®. Patient demographics, bone healing, time to bone healing, and complications were assessed. Results revealed a healing rate of 96.4% for the Shark Screw® group, compared to 82.3% for the conventionally treated group. The Shark Screw® group exhibited a tendency for faster bone healing (9.4 ± 3.2 vs. 12.9 ± 8.5 weeks, p = 0.05061). Hardware irritations led to six metal removals in the conventional group versus two in the Shark Screw® group. The Shark Screw® emerges as a promising option for personalized non-union treatment in the foot, ankle, and select lower leg cases, facilitating effective osteosynthesis and grafting within a single construct and promoting high union rates, low complications, and a rapid healing process.
Diabetic Neuropathy and Minimum Effective Anesthetic Concentration of Mepivacaine for Axillary Brachial Plexus Block: A Prospective Observational Study
Authors: Kim Na-Eun , Lee Woo-Joo , Jung Jong-Kwon , Song Jang-Ho , Joa Kyung-Lim , Yang Chun-Woo , Jung Eui-Chan , Jo Soo-Man , Ko Yeong-Seung
Published: March 2024

Nerves in patients with diabetic neuropathy (DN) show increased susceptibility to local anesthetics, potentially requiring a decreased dose. We investigated whether the minimum effective anesthetic concentration (MEAC) of mepivacaine for successful axillary block is lower in patients with DN than in those without. This prospective observational study included patients with DN (n = 22) and without diabetes (n = 22) at a tertiary care center. Patients received an ultrasound-guided axillary block with 30 mL of mepivacaine for anesthesia. The mepivacaine concentration used in each patient was calculated using Dixon’s up-and-down method. A block was considered successful if all four sensory nerves had a score of 1 or 2 within 30 min with no pain during surgery. The primary outcome was the MEAC of mepivacaine, and the secondary outcomes included the minimal nerve stimulation intensity for the musculocutaneous nerve and the occurrence of adverse events. The MEAC50 was 0.55% (95% CI 0.33–0.77%) in patients without diabetes and 0.58% (95% CI 0.39–0.77%) in patients with DN (p = 0.837). The MEAC90 was 0.98% (95% CI 0.54–1.42%) in patients without diabetes and 0.96% (95% CI 0.57–1.35%) in patients with DN (p = 0.949). The stimulation threshold for the musculocutaneous nerve was significantly different between groups (0.49 mA vs. 0.19 mA for patients with vs. without diabetes; p = 0.002). In conclusion, the MEAC of mepivacaine for a successful axillary block is not lower in patients with DN.
A Novel Approach to Semic Analysis: Extraction of Atoms of Meaning to Study Polysemy and Polyreferentiality
Authors: Bonato Vanessa , Di Nunzio Giorgio Maria , Vezzani Federica
Published: March 2024

Semic analysis is a linguistic technique aimed at methodically factorizing the meaning of terms into a collection of minimum non-decomposable atoms of meaning. In this study, we propose a methodology targeted at enhancing the systematicity of semic analysis of medical terminology in order to increase the quality of the creation of the set of atoms of meaning and improve the identification of concepts, as well as enhance specialized domain studies. Our approach is based on: (1) a semi-automatic domain-specific corpus-based extraction of semes, (2) the application of the property of termhood to address the diaphasic and the diastratic variations of language, (3) the automatic lemmatization of semes, and (4) seme weighting to establish the order of semes in the sememe. The paper explores the distinction between denotative and connotative semes, offering insights into polysemy and polyreferentiality in medical terminology.
Comparative Analysis of Metal Electrodeposition Rates towards Formation of High-Entropy WFeCoNiCu Alloy
Authors: Ratajczyk Tomasz , Donten Mikołaj
Published: March 2024

This study presents a calculation and comparison of Fe, Co, Ni and Cu deposition rates in the tungsten codeposition process based on the electrodeposition of numerous tungsten alloys. Eight different tungsten alloys containing from two to five metals were electrodeposited in constant conditions in order to compare the exact reduction rates. The calculated rates enabled control of the alloy composition precise enough to obtain a high-entropy WFeCoNiCu alloy with a well-balanced composition. The introduction of copper to form the quinternary alloy was found to catalyze the whole process, increasing the deposition rates of all the components of the high-entropy alloy.
Numerical Study on the Effect of Coarse Aggregate Shape during Concrete Mixing Process
Authors: Shen Jianjun , Wang Binqiang , Hou Jingru , Yao Pengchao
Published: March 2024

The shape of coarse aggregate is an important factor determining the performance of concrete, and it also affects the whole mixing process. This article selected four typical coarse aggregates and simulated the motion behavior of the coarse aggregate and mortar in a dual horizontal axis mixer using discrete element software, EDEM. The mixing motion of coarse aggregates with different shapes and mortar was studied using average velocity, contact rate, and dispersion coefficient as indicators. The results show that the largest average speed in the mixing process was achieved with the spherical coarse aggregate. Flat coarse aggregates have the highest velocity in the vertical direction, while ellipsoidal coarse aggregates have the lowest velocity. The spherical coarse aggregate mixes best with mortar while the ellipsoidal coarse aggregate mixes worst with mortar. The results of the study could provide strategies for the concrete mixing process considering the shape of the aggregate.
Tea Grounds as a Waste Biofiller for Natural Rubber
Authors: Juszkiewicz Aleksandra , Maciejewska Magdalena
Published: March 2024

The aim of this study was the utilization of ground tea waste (GT) left after brewing black tea as a biofiller in natural rubber (NR) composites. Ionic liquids (ILs), i.e., 1-ethyl-3-methylimidazolium lactate and 1-benzyl-3-methylimidazolium chloride, often used to extract phytochemicals from tea, were applied to improve the dispersibility of GT particles in the elastomeric matrix. The influence of GT loading and ILs on curing characteristics, crosslink density, mechanical properties, thermal stability and resistance of NR composites to thermo-oxidative aging was investigated. The amount of GT did not significantly affect curing characteristics and crosslink density of NR composites, but had serious impact on tensile properties. Applying 10 phr of GT improved the tensile strength by 40% compared to unfilled NR. Further increasing GT content worsened the tensile strength due to the agglomeration of biofiller in the elastomer matrix. ILs significantly improved the dispersion of GT particles in the elastomer and increased the crosslink density by 20% compared to the benchmark. Owing to the poor thermal stability of pure GT, it reduced the thermal stability of vulcanizates compared to unfilled NR. Above all, GT-filled NR exhibited enhanced resistance to thermo-oxidation since the aging factor increased by 25% compared to the unfilled vulcanizate.
Effects of Induction Plasma Spheroidization on Properties of Yttria-Stabilized Zirconia Powders for Thermal Barrier Coating Applications
Authors: Peng Haoran , Yu Yueguang , Shi Tianjie , Bai Botian , Yan Zheng , Yuan Kang
Published: March 2024

In this study, the induction plasma spheroidization (IPS) technique was adopted to improve the microstructure and properties of the traditional agglomerated ZrO2-7wt%Y2O3 (YSZ) powders used in thermal barrier coating (TBC) applications. Compared with agglomerated YSZ powders, IPS-treated powder has a more desirable microstructure, and the overall performance of the spray powders for TBC preparation is significantly improved. Specifically, IPS-treated powder has a dense, solid, defect-free, and chemically uniform microstructure, and its apparent density, flowability, and powder strength are significantly improved, which is believed to substantially enhance the coating performance when prepared with this IPS-treated powder.
Vibration Sensors on Flexible Substrates Based on Nanoparticle Films Grown by Physical Vapor Deposition
Authors: Aslanidis Evangelos , Sarigiannidis Savvas , Skotadis Evangelos , Tsoukalas Dimitris
Published: March 2024

Flexible electronics have gained a lot of attention in recent years due to their compatibility with soft robotics, artificial arms, and many other applications. Meanwhile, the detection of acoustic frequencies is a very useful tool for applications ranging from voice recognition to machine condition monitoring. In this work, the dynamic response of Pt nanoparticles (Pt NPs)-based strain sensors on flexible substrates is investigated. the nanoparticles were grown in a vacuum by magnetron-sputtering inert-gas condensation. Nanoparticle sensors made on cracked alumina deposited by atomic layer deposition on the flexible substrate and reference nanoparticle sensors, without the alumina layer, were first characterized by their response to strain. The sensors were then characterized by their dynamic response to acoustic frequency vibrations between 20 Hz and 6250 Hz. The results show that alumina sensors outperformed the reference sensors in terms of voltage amplitude. Sensors on the alumina layer could accurately detect frequencies up to 6250 Hz, compared with the reference sensors, which were sensitive to frequencies up to 4250 Hz, while they could distinguish between two neighboring frequencies with a difference of no more than 2 Hz.
Experimental Investigation on Magnetic Abrasive Finishing for Internal Surfaces of Waveguides Produced by Selective Laser Melting
Authors: Wang Liaoyuan , Sun Yuli , Xiao Zhongmin , Yao Liming , Guo Jiale , Kang Shijie , Mao Weihao , Zuo Dunwen
Published: March 2024

To enhance the surface quality of metal 3D-printed components, magnetic abrasive finishing (MAF) technology was employed for post-processing polishing. Experimental investigation employing response surface methodology was conducted to explore the impact of processing gap, rotational speed of the magnetic field, auxiliary vibration, and magnetic abrasive particle (MAP) size on the quality enhancement of internal surfaces. A regression model correlating roughness with crucial process parameters was established, followed by parameter optimization. Ultimately, the internal surface finishing of waveguides with blind cavities was achieved, and the finishing quality was comprehensively evaluated. Results indicate that under optimal process conditions, the roughness of the specimens decreased from Ra 2.5 μm to Ra 0.65 μm, reflecting a reduction rate of 74%. Following sequential rough and fine processing, the roughnesses of the cavity bottom, side wall, and convex surface inside the waveguide reduced to 0.59 μm, 0.61 μm, and 1.9 μm, respectively, from the original Ra above 12 μm. The findings of this study provide valuable technical insights into the surface finishing of metal 3D-printed components.
Sampling Points-Independent Identification of the Fractional Maxwell Model of Viscoelastic Materials Based on Stress Relaxation Experiment Data
Authors: Stankiewicz Anna
Published: March 2024

Considerable development has been observed in the area of applying fractional-order rheological models to describe the viscoelastic properties of miscellaneous materials in the last few decades together with the increasingly stronger adoption of fractional calculus. The fractional Maxwell model is the best-known non-integer-order rheological model. A weighted least-square approximation problem of the relaxation modulus by the fractional Maxwell model is considered when only the time measurements of the relaxation modulus corrupted by additive noises are accessible for identification. This study was dedicated to the determination of the model, optimal in the sense of the integral square weighted model quality index, which does not depend on the particular sampling points applied in the stress relaxation experiment. It is proved that even when the real description of the material relaxation modulus is entirely unknown, the optimal fractional Maxwell model parameters can be recovered from the relaxation modulus measurements recorded for sampling time points selected randomly according to respective randomization. The identified model is a strongly consistent estimate of the desired optimal model. The exponential convergence rate is demonstrated both by the stochastic convergence analysis and by the numerical studies. A simple scheme for the optimal model identification is given. Numerical studies are presented for the materials described by the short relaxation times of the unimodal Gauss-like relaxation spectrum and the long relaxation times of the Baumgaertel, Schausberger and Winter spectrum. These studies have shown that the appropriate randomization introduced in the selection of sampling points guarantees that the sequence of the optimal fractional Maxwell model parameters asymptotically converge to parameters independent of these sampling points. The robustness of the identified model to the measurement disturbances was demonstrated by analytical analysis and numerical studies.
Analytical Approach for Forecasting the Load Capacity of the EN AW-7075-T6 Aluminum Alloy Joints Created Using RFSSW Technology
Authors: Kluz Rafał , Bucior Magdalena , Kubit Andrzej , Trzepieciński Tomasz , Antosz Katarzyna , Faes Koen
Published: March 2024

To ensure the high reliability of aircraft structures, the Refill Friction Stir Spot Welding (RFSSW) process must be characterized by a high load capacity of the welds and a small standard deviation of the load capacity spread. This allows us to obtain uniform functional properties in the connections, ensuring the high quality of the process. This work aims to select the most favorable technological parameters for the welding process of EN AW-7075-T6 Alclad aluminum alloy sheets, which are used for the production of aircraft structures. The best networks were calculated using the Statistica 13.3 program. The obtained results were compared with the results of previous investigations. It has been shown that a model using neural networks allows for the determination of connection parameters with much greater accuracy than the classical model. The maximum error in estimating the load capacity of the connection for the mathematical model was 6.13%, and the standard deviation was 14.51%. In the case of neural networks, the maximum error value did not exceed 1.55%, and the standard deviation was 3.74%. It was shown that, based on the neural model, it is possible to determine the process parameters that ensure the required quality capacity of the process, ensuring a probability of obtaining the required load capacity of the connections amounting to P = 0.999935 with a defect rate of 0.0065%. This possibility is not provided by the classical model due to its large error in estimating the process spread and the high sensitivity of the process input parameters to the output parameters.
Estimation of the Band Gap of Carbon Nanotube Bundles
Authors: Ding Yi , Chen Jing-Zhe
Published: March 2024

The electronic structure of carbon nanotube bundles (CNTBs) can be a tough task for the routine first-principle calculation. The difficulty comes from several issues including the atomic structure, the boundary condition, and above all the very large number of atoms that makes the calculation quite cumbersome. In this work, we estimated the band gap of the CNTBs based on the results from single-walled carbon nanotubes (SWCNTs) under different deformations. The effects of squeezing, stretching, and torsion on the bands of SWCNTs were investigated through first-principle calculations, from which the band gaps of bundles were analyzed because the effects of these deformations were qualitatively independent when the distortions were small. Specifically, the gaps of (4,4) and (8,0) CNTBs under a reasonable torsional strength were predicted, wherein we were able to see metal–semiconductor and semiconductor–metal transitions, respectively. Such reversible mechanical modification of the conductivity may be helpful to the future band-gap engineering in nanoscale circuits.
Study of Mechanics and Durability of Non-Spontaneous Combustion Coal Gangue Coarse-Aggregate High-Performance Concrete
Authors: Wang Zhigang , Ma Hongqiang , Niu Xiaoyan
Published: March 2024

The coal gangue coarse-aggregate content in ordinary concrete should not be too large. In order to further improve the utilization rate of coal gangue coarse aggregate, this study used the principle of “strong wrapped weak” to prepare high-performance concrete. This study considered four factors, namely, water–binder (W/B) ratios, non-spontaneous combustion coal gangue (NCCG) coarse-aggregate contents, fly ash–slag mass ratios, and silica fume coating to prepare high-performance concrete. The workability, mechanical, and durability properties were studied, and the changes in the interfacial transition zone (ITZ) of concrete before and after sulfate attack and freeze–thaw cycles were analyzed based on the SEM test. The life prediction of NCCG coarse-aggregate high-performance concrete was carried out based on the grey system GM(1,1) prediction model. The results show that the NCCG coarse-aggregate contents have the greatest effect on compressive strength, sulfate resistance, and frost resistance. The W/B ratio has the greatest effect on the anti-carbonization properties. Fly ash–slag mixing can obtain better durability. Considering the effect on the design service life of high-performance concrete, NCCG coarse aggregate is used to prepare high-performance concrete in North China, and the recommended content is 60%; in the Northwest and Northeast regions, the recommended content is 45%. This study provides a basis for the preparation of high-performance concrete with NCCG coarse aggregate.
Coherent Chaotic Communication Using Generalized Runge–Kutta Method
Authors: Babkin Ivan , Rybin Vyacheslav , Andreev Valery , Karimov Timur , Butusov Denis
Published: March 2024

Computer simulation of continuous chaotic systems is usually performed using numerical methods. The discretization may introduce new properties into finite-difference models compared to their continuous prototypes and can therefore lead to new types of dynamical behavior exhibited by discrete chaotic systems. It is known that one can control the dynamics of a discrete system using a special class of integration methods. One of the applications of such a phenomenon is chaos-based communication systems, which have recently attracted attention due to their high covertness and broadband transmission capability. Proper modulation of chaotic carrier signals is one of the key problems in chaos-based communication system design. It is challenging to modulate and demodulate a chaotic signal in the same way as a conventional signal due to its noise-like shape and broadband characteristics. Therefore, the development of new modulation–demodulation techniques is of great interest in the field. One possible approach here is to use adaptive numerical integration, which allows control of the properties of the finite-difference chaotic model. In this study, we describe a novel modulation technique for chaos-based communication systems based on generalized explicit second-order Runge–Kutta methods. We use a specially designed test bench to evaluate the efficiency of the proposed modulation method and compare it with state-of-the-art solutions. Experimental results show that the proposed modulation technique outperforms the conventional parametric modulation method in both coverage and noise immunity. The obtained results can be efficiently applied to the design of advanced chaos-based communication systems as well as being used to improve existing architectures.
Toward the Usage of Deep Learning Surrogate Models in Ground Vehicle Aerodynamics
Authors: Eiximeno Benet , Miró Arnau , Rodríguez Ivette , Lehmkuhl Oriol
Published: March 2024

This study introduces a deep learning surrogate model designed to predict the evolution of the mean pressure coefficient on the back face of a Windsor body across a range of yaw angles from 2.5∘ to 10∘. Utilizing a variational autoencoder (VAE), the model effectively compresses snapshots of back pressure taken at yaw angles of 2.5∘, 5∘, and 10∘ into two latent vectors. These snapshots are derived from wall-modeled large eddy simulations (WMLESs) conducted at a Reynolds number of ReL=2.9×106. The frequencies that dominate the latent vectors correspond closely with those observed in both the drag’s temporal evolution and the dynamic mode decomposition. The projection of the mean pressure coefficient to the latent space yields an increasing linear evolution of the two latent variables with the yaw angle. The mean pressure coefficient distribution at a yaw angle of 7.5∘ is predicted with a mean error of e¯=3.13% when compared to the WMLESs results after obtaining the values of the latent space with linear interpolation.
Marine-Fungus-Derived Natural Compound 4-Hydroxyphenylacetic Acid Induces Autophagy to Exert Antithrombotic Effects in Zebrafish
Authors: Xin Shaoshuai , Zhang Mengqi , Li Peihai , Wang Lizhen , Zhang Xuanming , Zhang Shanshan , Mu Zhenqiang , Lin Houwen , Li Xiaobin , Liu Kechun
Published: March 2024

Marine natural products are important sources of novel drugs. In this study, we isolated 4-hydroxyphenylacetic acid (HPA) from the marine-derived fungus Emericellopsis maritima Y39–2. The antithrombotic activity and mechanism of HPA were reported for the first time. Using a zebrafish model, we found that HPA had a strong antithrombotic activity because it can significantly increase cardiac erythrocytes, blood flow velocity, and heart rate, reduce caudal thrombus, and reverse the inflammatory response caused by Arachidonic Acid (AA). Further transcriptome analysis and qRT–PCR validation demonstrated that HPA may regulate autophagy by inhibiting the PI3K/AKT/mTOR signaling pathway to exert antithrombotic effects.
Unlocking the Therapeutic Potential of Freshwater Sapropel Extracts: In Vitro Analysis and Antioxidant Profiling for Skincare Applications
Authors: Kļaviņa Aneka , Reste Jeļena , Mārtiņsone Inese , Vanadziņš Ivars , Lece Anna , Pavlovska Ilona
Published: March 2024

Background and Objective: Sapropel, a biologically active sedimentary deposit, is high in organic matter and minerals and has been shown to offer health benefits. Its constituents, humic acid (HA) and fulvic acid (FA), have been found to have some therapeutic applications. The aim of this study was to determine the potential therapeutically significant properties of freshwater sapropel extracts: their polyacid content, antioxidative (AO) status, and biological activity in cell culture. Materials and Methods: Freshwater lakes from the southeast region of Latvia were investigated layer by layer. The total organic carbon (TOC) was determined through combustion using the catalytic oxidation method, HA and FA were measured via acid perspiration, and the total polyphenol content (TPC) and total antioxidant status (TAS) was analysed spectrophotometrically. Sapropel extracts’ regenerative abilities were tested in vitro using a Cell-IQ real-time monitoring system on mouse BALB/c 3T3 fibroblasts and human keratinocyte HaCaT cell lines. Cytotoxicity was measured through neutral red uptake assessment as a concentration-dependent reduction in the uptake of neutral red dye relative to a vehicle control or untreated cells. Results: The highest AO activity was observed in sapropel extracts with elevated concentrations of HA and TPC from Audzelu Lake (1.08 ± 0.03 mmol/L), and the lowest activity was found in extracts from Ivusku Lake (0.31 ± 0.01 mmol/L). Correspondingly, the concentrations of HA in Audzelu and Ivusku Lakes were recorded as 45.2 and 27.4 mg/g, respectively. High concentrations of HA promoted in vitro cell growth upon short-term exposure (up to 6 h). Conclusions: The results show that high TPC correlates with AO status and sapropel extracts with higher concentrations of HA exhibit greater AO activity and promote in vitro cell growth, suggesting a perspective use for short-term topical therapeutic skin applications. However, higher concentrations over longer durations showed cytotoxic effects, indicating the need for further investigation.