bluuebunny/crossref_metadata_2025 huggingface dataset:
Carbon Fiber 3D Printing: Technologies and Performance—A Brief Review
Authors: Marabello Gabriele , Borsellino Chiara , Di Bella Guido
Published: November 2023

Additive manufacturing is evolving in the direction of carbon fiber 3D printing, a technology that combines the versatility of three-dimensional printing with the exceptional properties of carbon fiber. This work aims to provide a brief review of the main methodologies used in carbon fiber 3D printing, focusing particularly on the two most widespread types: continuous fiber printing and short fiber printing. In the context of continuous fiber printing, the process of embedding a continuous carbon fiber into a polymer matrix will be examined, resulting in the achievement of high-performance lightweight structural components. On the other hand, short fiber printing involves the use of short carbon fibers mixed in turn with polymeric materials, with the advantage of having greater ease of processing and obtaining highly performing components with large-scale economic investments that are lower in cost than additive manufacturing using continuous fiber printing. Furthermore, this work will conduct an evaluation of the mechanical properties of products printed using both technologies, focusing on key aspects, such as strength, stiffness, weight, and resistance to mechanical stress. The specific advantages and challenges associated with each printing technique will also be analyzed.
Design and Structural Factors’ Influence on the Fatigue Life of Steel Products with Additive Manufacturing
Authors: Kazantseva Nataliya , Il’inikh Maxim , Kuznetsov Victor , Koemets Yulia , Bakhrunov Konstantin , Karabanalov Maxim
Published: November 2023

The influence of implant design and structural factors on fatigue life under cyclic loading was investigated. The implants were manufactured from 316L steel powder using 3D printing for medical use. A simulation model of implant deformation was built using ANSYS software. The obtained data showed that the geometry of the implant had the necessary margin of safety for osseointegration time. It was found that the stress concentration factor, which is associated with fatigue life, for an implant with a hexagon head and internal thread depends on the mechanical properties of the metal, design, and load conditions. The presence of internal threads and holes in the implant increases the stress concentration factor by more than 10 times. The number of load cycles for the failure of the implant, which was calculated by taking into account a coefficient for reducing the endurance limit, was found to be sufficient for implant osseointegration.
Research Progress on the Damping Mechanism of Magnesium Alloys
Authors: Wang Jinxing , Wan Zhicheng , Dang Cong , Zou Yi , Wang Jingfeng , Pan Fusheng
Published: November 2023

Magnesium alloys with high damping, high specific strength and low density have attracted great attention in recent years. However, the application of magnesium alloys is limited by the balance between their mechanical and damping properties. The strength and plasticity of magnesium alloys with high damping performance often cannot meet the industrial requirements. Understanding the damping mechanism of magnesium alloys is significant for developing new materials with high damping and mechanical properties. In this paper, the damping mechanisms and internal factors of the damping properties of magnesium alloys are comprehensively reviewed. Some damping mechanisms have been studied by many scholars, and it has been found that they can be used to explain damping performance. Among existing damping mechanisms, the G-L dislocation theory, twin damping mechanism and interface damping mechanism are considered common. In addition, some specific long-period stacking ordered (LPSO) phases’ crystal structures are conducive to dislocation movement, which is good for improving damping performance. Usually, the damping properties of magnesium alloys are affected by some internal factors directly, such as dislocation density, solute atoms, grain texture and boundaries, etc. These internal factors affect damping performance by influencing the dissipation of energy within the crystal. Scholars are working to find novel damping mechanisms and suitable solute atoms that can improve damping performance. It is important to understand the main damping mechanisms and the internal factors for guiding the development of novel high-damping magnesium alloys.
Poly(glycerol itaconate) Crosslinking via the aza-Michael Reaction—A Preliminary Research
Authors: Miętus Magdalena , Kolankowski Krzysztof , Gołofit Tomasz , Ruśkowski Paweł , Mąkosa-Szczygieł Marcin , Gadomska-Gajadhur Agnieszka
Published: November 2023

In unsaturated glycerol polyesters, the C=C bond is present. It makes it possible to carry out post-polymerisation modification (PPM) reactions, such as aza-Michael addition. This reaction can conduct crosslinking under in-situ conditions for tissue engineering regeneration. Until now, no description of such use of aza-Michael addition has been described. This work aims to crosslink the synthesised poly(glycerol itaconate) (PGItc; P3), polyester from itaconic acid (AcItc), and glycerol (G). The PGItc syntheses were performed in three ways: without a catalyst, in the presence of p-toluenesulfonic acid (PTSA), and in the presence of zinc acetate (Zn(OAc)2). PGItc obtained with Zn(OAc)2 (150 °C, 4 h, G:AcItc = 2:1) was used to carry out the aza-Michael additions. Crosslinking reactions were conducted with each of the five aliphatic diamines: 1,2-ethylenediamine (1,2-EDA; A1), 1,4-butanediamine (1,4-BDA; A2), 1,6-hexanediamine (1,6-HDA; A3), 1,8-octanediamine (1,8-ODA; A4), and 1,10-decanediamine (1,10-DDA; A5). Four ratios of the proton amine group: C=C bond were investigated. The maximum temperature and crosslinking time were measured to select the best amine for the addition product’s application. FTIR, 1H NMR, DSC, and TG analysis of the crosslinked products were also investigated.
Improved Resistive Switching Characteristics and Synaptic Functions of InZnO/SiO2 Bilayer Device
Authors: Ju Dongyeol , Koo Minsuk , Kim Sungjun
Published: November 2023

This paper investigates the bipolar resistive switching and synaptic characteristics of IZO single-layer and IZO/SiO2 bilayer two-terminal memory devices. The chemical properties and structure of the device with a SiO2 layer are confirmed by x-ray photoemission spectroscopy (XPS) and transmission electron microscopy (TEM) imaging. The device with the SiO2 layer showed better memory characteristics with a low current level, as well as better cell-to-cell and cycle-to-cycle uniformity. Moreover, the neuromorphic applications of the IZO/SiO2 bilayer device are demonstrated by pulse response. Paired pulse facilitation, excitatory postsynaptic current, and pulse-width-dependent conductance changes are conducted by the coexistence of short- and long-term memory characteristics. Moreover, Hebbian rules are emulated to mimic biological synapse function. The result of potentiation, depression, spike-rate-dependent plasticity, and spike-time-dependent plasticity prove their favorable abilities for future applications in neuromorphic computing architecture.
Experimental and Statistical Analysis of the Effect of Heat Treatment on Surface Roughness and Mechanical Properties of Thin-Walled Samples Obtained by Selective Laser Melting from the Material AlSi10Mg
Authors: Grigoriev Sergey N. , Nikitin Nikita , Yanushevich Oleg , Kriheli Natella , Kramar Olga , Khmyrov Roman , Idarmachev Idarmach , Peretyagin Pavel
Published: November 2023

Statistical analysis of mechanical properties of thin-walled samples (~500 microns) obtained by selective laser melting from AlSi10Mg material and subjected to heat treatment for 1 h at temperatures from 260 °C to 440 °C (step of aging temperature change 30 °C) has shown that the maximum strain hardening in the stretching diagram section from yield strength to tensile strength is achieved at the heat treatment temperature equal to 290 °C. At carrying out of correlation analysis, a statistically significant positive correlation between deformation corresponding to yield strength and the sum of heights of the largest protrusions and depths of the largest depressions of the surface roughness profile within the basic length of the sample (Rz) and the full height of the surface roughness profile (Rmax) was established. It was found that the reason for the correlation is the presence of cohesive states between the extreme values of the surface roughness profile that persist along the entire length of the specimen.
Recent Developments in Ultrafine Shape Memory Alloys Using Amorphous Precursors
Authors: Hong Sung-Hwan , Park Hae-Jin , Song Gi-An , Kim Ki-Buem
Published: November 2023

In this review, we systematically reviewed the recent advances in the development of ultrafine shape memory alloys with unique shape memory effects and superelastic behavior using amorphous metallic materials. Its scientific contribution involves defining and expanding the range of fabrication methods for single-phase ultrafine/nanocrystalline alloys with multicomponent systems. In multicomponent amorphous alloys, the crystallization mechanism depends on the alloy composition and is a selectable factor in the alloy designing method, considering the thermodynamic and physical parameters of constituent elements. The crystallization kinetics can be controlled by modulating the annealing condition in a supercooled liquid state with consideration of the crystalline temperature of the amorphous alloys. The phase stability of austenite and martensite phases in ultrafine shape memory alloys developed from amorphous precursors is determined according to alloy composition and grain size, which strongly influence the shape memory effect and superelastic behavior. A methodological framework is subsequently suggested to develop the ultrafine shape memory alloys based on the systematic alloy designing method, which can be considered an important strategy for developing novel ultrafine/nanocrystalline shape memory alloys with excellent shape memory and superelastic effects.
Effect of Frequency and Ratio of Wet/Dry Stages in Cyclic Corrosion Tests on Localized Corrosion of Complex-Phase High-Strength Steel
Authors: Yoo Jin-Seok , Kim Geon-Il , Kim Jung-Gu
Published: November 2023

This study delves into the atmospheric corrosion behavior of chromium-free complex-phase (CP) steel, specifically investigating the influence of wet/dry frequency and ratio in cyclic corrosion tests (CCT). The study employs a modified ISO 14993 standard CCT method, which involves salt spray, dry, and wet stages. After 15 and 30 CCT cycles, mass loss, maximum corrosion depth, and corrosion products were analyzed to gain insights into corrosion mechanisms. In general, increasing the frequency and wet/dry stage ratio in CCT extends the time for autocatalytic reactions to occur, leading to accelerated localized CP steel corrosion and increased pitting factors. However, as the rust layer thickens, uniform corrosion may also intensify, so careful considerations are necessary. This study underscores the importance of controlling the frequency and ratio of wet/dry stages in CCT for effectively analyzing localized corrosion behavior in specimens.
The Synthesis of Well-Dispersed and Uniform-Sized Zeolite NaY by Adding Non-Refluxed and Acid-Refluxed Cogon Grass
Authors: Sereerattanakorn Pakawan , Tayraukham Pimwipa , Osakoo Nattawut , Krukkratoke Panot , Keawkumay Chalermpan , Wittayakun Jatuporn , Pornnongsan Nichakorn , Deekamwong Krittanun , Prayoonpokarach Sanchai
Published: November 2023

Zeolite NaY synthesized from a typical procedure could suffer from agglomeration. Adding non-refluxed cogon grass (NG) to the synthesis gel could produce NaY with good dispersion and uniform crystal size. Small molecules produced from cogon grass in alkaline conditions could prevent agglomeration. The obtained zeolite (Y-NG) has a crystallinity and surface area comparable to the synthesis without grass (Y-WG). Y-NG demonstrated similar paraquat adsorption capacity to Y-WG at high initial concentrations. On the other hand, the zeolite from the addition of acid-refluxed grass (Y-RG) has the lowest crystallinity, smallest surface area, and poorest paraquat adsorption capacity. The effect of grass amount on the zeolite structure was studied. One gram of cogon grass was the optimum amount to add to the synthesis gel.
A New Direct and Inexpensive Method and the Associated Device for the Inspection of Spur Gears
Authors: Alaci Stelian , Ciornei Florina-Carmen , Romanu Ionut-Cristian , Doroftei Ioan , Bujoreanu Carmen , Tamașag Ioan
Published: November 2023

This paper proposes a new rapid and straightforward method along with a related device for finding the three basic parameters of an actual external involute spur gear. The number of teeth is easily counted, but the other two parameters—the module and the coefficient of profile shift—are difficult to identify. The method is based on the principle of inspection of the precision of gear teeth, using the dimension over pins, when the maximum distance is measured between the lateral surfaces of two cylindrical rollers of well-controlled dimensions, placed into the spaces between teeth. The dimension over pins is applied as a function of the number of teeth (odd or even) and requires experience (and this is the main disadvantage of the method) for finding the correct maximum distance between pins. The new method eliminates this drawback as it proposes a measuring scheme where four identical rollers are used in a designed inspection device. The system is statically determinate and, therefore, the dimension to be measured is unequivocally found. A new relation for the dimension to be measured is deduced and allows for finding the module and the coefficient of profile shift. The inspection device is described and a concrete case is presented for exemplifying the methodology. A further application permits finding the centre distance for an external spur gearing. Unlike the classical technique where the centre distance is obtained based on the centring surfaces of the wheels, the new method implies only dimensions measured through flank measurements, thus eliminating errors introduced by the deviations between the flanks and the centring surfaces of the wheels.
Topology Optimization of Geometrically Nonlinear Structures Based on a Self-Adaptive Material Interpolation Scheme
Authors: Liang Junwen , Zhang Xianmin , Zhu Benliang , Wang Rixin , Cui Chaoyu , Zhang Hongchuan
Published: November 2023

In this paper, a simple and effective self-adaptive material interpolation scheme is proposed to solve the numerical instability problem, which may occur in topology optimization considering geometrical nonlinearity when using density-based method. The primary concept of the proposed method revolves around enhancing the deformation resistance of minimum-density or intermediatedensity elements, thus avoiding numerical instability due to excessive distortion of these elements. The proposed self-adaptive material interpolation scheme is based on the power law method, and the stiffness of minimum-density or intermediate-density elements can be adjusted by a single parameter, α. During the optimization process, the parameter α will be changed according to an adaptive adjustment strategy to ensure that elements within the design domain are not excessively distorted, while the mechanical behavior of the structure can be approximated with acceptable accuracy. Numerical examples of minimizing compliance and maximizing displacement of structure are given to prove the validity of the proposed self-adaptive material interpolation scheme.
Index Matrix-Based Modeling and Simulation of Buck Converter
Authors: Hinov Nikolay , Gocheva Polya , Gochev Valeri
Published: November 2023

The approach described in this paper handles the parameters and characteristics (analog and discrete ones) of a Buck DC-DC converter (in its power and control parts) in a common manner. The usage of probably complicated differential equations for discrete dynamical systems is avoided by means of index matrix equations, which can be easily understood. Compared to classical matrix models, the proposed index matrix models are more descriptive and also smaller in size. Such functionality is widely applied by the authors, and a new operation is defined and used as well. The relevance of the proposed techniques in power electronics, because of switching topologies and a limited numbers of components, is argued. Respective examples of functioning modes of the considered converter, in which power circuits and controllers are modeled jointly, are given. Estimations of analog values are based on partly linear dependencies, which are shown to be adequate in first-order analyses. Specific expressions for a Buck DC-DC converter are presented. A model-solving technique and an exhaustive search on a parameter space are considered in detail and automated via well-formalized algorithms. Nested parameter intervals and verifications with normal probability distributions are used in an optimization procedure. The full agreement of implementation via MATLAB source code with results obtained via Simulink is demonstrated. The short simulation times of this software (compared to Simulink and a .NET desktop application developed by the authors) justify the search for optimal variants in a wide multi-dimensional space. A max–min procedure with 10,000 simulations in each verification step is presented.
Preparation and Antioxidant Activity of New Carboxymethyl Chitosan Derivatives Bearing Quinoline Groups
Authors: Wang Linqing , Guo Rui , Liang Xiaorui , Ji Yuting , Zhang Jingjing , Gai Guowei , Guo Zhanyong
Published: November 2023

A total of 16 novel carboxymethyl chitosan derivatives bearing quinoline groups in four classes were prepared by different synthetic methods. Their chemical structures were confirmed by Fourier-transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), and elemental analysis. The antioxidant experiment results in vitro (including DPPH radical scavenging ability, superoxide anion radical scavenging ability, hydroxyl radical scavenging ability, and ferric reducing antioxidant power) demonstrated that adding quinoline groups to chitosan (CS) and carboxymethyl chitosan (CMCS) enhanced the radical scavenging ability of CS and CMCS. Among them, both N, O-CMCS derivatives and N-TM-O-CMCS derivatives showed DPPH radical scavenging over 70%. In addition, their scavenging of superoxide anion radicals reached more than 90% at the maximum tested concentration of 1.6 mg/mL. Moreover, the cytotoxicity assay was carried out on L929 cells by the MTT method, and the results indicated that all derivatives showed no cytotoxicity (cell viability > 75%) except O-CMCS derivative 1a, which showed low cytotoxicity at 1000 μg/mL (cell viability 50.77 ± 4.67%). In conclusion, the carboxymethyl chitosan derivatives bearing quinoline groups showed remarkable antioxidant ability and weak cytotoxicity, highlighting their potential use in food and medical applications.
Simulation Analysis of a Sandwich Cantilever Ultrasonic Motor for a Dexterous Prosthetic Hand
Authors: Guo Kai , Lu Jingxin , Yang Hongbo
Published: November 2023

Currently, the driving motor used in a dexterous prosthetic hand is limited by the driving principle, and it has the characteristics of a complex structure, slow response, low positioning accuracy, and excessive volume. There are special requirements in terms of quality and quality, and traditional motor drives have greatly affected the progress of prosthetic robots. A motor (ultrasonic motor) has been developed over more than 30 years. It has the advantages of a small size, small mass, simple structure, accurate positioning, high power density, and fast response time, which is enough to improve the driving mechanism performance of the prosthetic hand with a connecting rod. In this paper, the structural characteristics of the prosthetic hand will be analyzed, and the modal analysis, harmonic response analysis, and transient analysis simulation of the longitudinal vibration linear motor stator used in the prosthetic hand with a connecting rod will be carried out in order to provide preliminary preparation for the feasible design and manufacture of the size of the ultrasonic driver structure used for the prosthetic hand with a connecting rod.
Recent Advances and Synergistic Effects of Non-Precious Carbon-Based Nanomaterials as ORR Electrocatalysts: A Review
Authors: Payattikul Laksamee , Chen Chen-Yu , Chen Yong-Song , Raja Pugalenthi Mariyappan , Punyawudho Konlayutt
Published: November 2023

The use of platinum-free (Pt) cathode electrocatalysts for oxygen reduction reactions (ORRs) has been significantly studied over the past decade, improving slow reaction mechanisms. For many significant energy conversion and storage technologies, including fuel cells and metal–air batteries, the ORR is a crucial process. These have motivated the development of highly active and long-lasting platinum-free electrocatalysts, which cost less than proton exchange membrane fuel cells (PEMFCs). Researchers have identified a novel, non-precious carbon-based electrocatalyst material as the most effective substitute for platinum (Pt) electrocatalysts. Rich sources, outstanding electrical conductivity, adaptable molecular structures, and environmental compatibility are just a few of its benefits. Additionally, the increased surface area and the simplicity of regulating its structure can significantly improve the electrocatalyst’s reactive sites and mass transport. Other benefits include the use of heteroatoms and single or multiple metal atoms, which are capable of acting as extremely effective ORR electrocatalysts. The rapid innovations in non-precious carbon-based nanomaterials in the ORR electrocatalyst field are the main topics of this review. As a result, this review provides an overview of the basic ORR reaction and the mechanism of the active sites in non-precious carbon-based electrocatalysts. Further analysis of the development, performance, and evaluation of these systems is provided in more detail. Furthermore, the significance of doping is highlighted and discussed, which shows how researchers can enhance the properties of electrocatalysts. Finally, this review discusses the existing challenges and expectations for the development of highly efficient and inexpensive electrocatalysts that are linked to crucial technologies in this expanding field.
The Cell Adhesion Activity of the Joining Peptide of Proopiomelanocortin
Authors: Hiroshima Kyona , Sakata Nana , Konogami Tadafumi , Shimamoto Shigeru , Hidaka Yuji
Published: November 2023

Proopiomelanocortin (POMC) is a precursor protein of several peptide hormones, such as ACTH and β-endorphin. Almost all of the peptide hormones in POMC have been drastically investigated in terms of their biological activities. However, the biological activity of the joining peptide region (JP) in POMC is unknown. Therefore, to explore the biological activity of JP, sequence analyses of mammalian POMC were performed. We found an -Arg-Gly-Asp- (RGD) motif in several mammalian species, such as porcine, suggesting that JP has cell adhesion activity. To validate this hypothesis, the cell adhesion activities of the synthetic porcine JP peptides were examined using 293T cells. Cell adhesions were observed in a concentration-dependent manner of the JP peptides. In addition, the JP peptide competitively inhibited cell adhesion to the POMC-coated plates. Moreover, the cell adhesion activity of the joining peptide was inhibited by the addition of EDTA, indicating that the JP peptide mediates the cell adhesion activity via a receptor protein, integrin. Interestingly, a human JP peptide, which possesses an -Arg-Ser-Asp- (RSD) sequence in place of the RGD sequence, exhibited a higher ability in the cell adhesion activity than that of the porcine JP peptide, suggesting that the cell adhesion activity of the joining peptide is developed during the molecular evolution of POMC. In conclusion, our results reveal that the joining peptide in POMC plays an important role during cell adhesion and provide useful information related to signal transduction of nerve peptide hormones derived from POMC.
Urea-Functionalized Heterocycles: Structure, Hydrogen Bonding and Applications
Authors: Keszei Soma J. , Váradi Márk , Skoda-Földes Rita
Published: November 2023

Ureido-heterocycles exhibiting different triple- and quadruple H-bonding patterns are useful building blocks in the construction of supramolecular polymers, self-healing materials, stimuli-responsive devices, catalysts and sensors. The heterocyclic group may provide hydrogen bond donor/acceptor sites to supplement those in the urea core, and they can also bind metals and can be modified by pH, redox reactions or irradiation. In the present review, the main structural features of these derivatives are discussed, including the effect of tautomerization and conformational isomerism on self-assembly and complex formation. Some examples of their use as building blocks in different molecular architectures and supramolecular polymers, with special emphasis on biomedical applications, are presented. The role of the heterocyclic functionality in catalytic and sensory applications is also outlined.
A Natural Compound Containing a Disaccharide Structure of Glucose and Rhamnose Identified as Potential N-Glycanase 1 (NGLY1) Inhibitors
Authors: Liu Ruijie , Gu Jingjing , Ye Yilin , Zhang Yuxin , Zhang Shaoxing , Lin Qiange , Yuan Shuying , Chen Yanwen , Lu Xinrong , Tong Yongliang , Lv Shaoxian , Chen Li , Sun Guiqin
Published: November 2023

N-glycanase 1 (NGLY1) is an essential enzyme involved in the deglycosylation of misfolded glycoproteins through the endoplasmic reticulum (ER)-associated degradation (ERAD) pathway, which could hydrolyze N-glycan from N-glycoprotein or N-glycopeptide in the cytosol. Recent studies indicated that NGLY1 inhibition is a potential novel drug target for antiviral therapy. In this study, structure-based virtual analysis was applied to screen candidate NGLY1 inhibitors from 2960 natural compounds. Three natural compounds, Poliumoside, Soyasaponin Bb, and Saikosaponin B2 showed significantly inhibitory activity of NGLY1, isolated from traditional heat-clearing and detoxifying Chinese herbs. Furthermore, the core structural motif of the three NGLY1 inhibitors was a disaccharide structure with glucose and rhamnose, which might exert its action by binding to important active sites of NGLY1, such as Lys238 and Trp244. In traditional Chinese medicine, many compounds containing this disaccharide structure probably targeted NGLY1. This study unveiled the leading compound of NGLY1 inhibitors with its core structure, which could guide future drug development.
Survey on Antioxidants Used as Additives to Improve Biodiesel’s Stability to Degradation through Oxidation
Authors: David Elena , Kopac Janez
Published: November 2023

A major problem that limits the use of biodiesel is maintaining the fuel at the specified standards for a longer period. Biodiesel oxidizes much more easily than diesel, and the final oxidation products change its physical and chemical properties and cause the formation of insoluble gums that can block fuel filters and the supply pipes. This instability of biodiesel is a major problem and has not yet been satisfactorily resolved. Recently, the use of biodiesel has increased quite a lot, but the problem related to oxidation could become a significant impediment. A promising and cost-effective approach to improving biodiesel’s stability is to add appropriate antioxidants. Antioxidants work better or less effectively in different biodiesel fuels, and there is no one-size-fits-all inhibitor for every type of biodiesel fuel. To establish a suitable antioxidant for a certain type of biodiesel, it is necessary to know the chemistry of the antioxidants and factors that influence their effectiveness against biodiesel oxidation. Most studies on the use of antioxidants to improve the oxidative stability of biodiesel have been conducted independently. This study presents an analysis of these studies and mentions factors that must be taken into account for the choice of antioxidants so that the storage stability of biodiesel fuels can be improved.
Artificial Synapses Based on an Optical/Electrical Biomemristor
Authors: Wang Lu , Wei Shutao , Xie Jiachu , Ju Yuehang , Yang Tianyu , Wen Dianzhong
Published: November 2023

As artificial synapse devices, memristors have attracted widespread attention in the field of neuromorphic computing. In this paper, Al/polymethyl methacrylate (PMMA)/egg albumen (EA)–graphene quantum dots (GQDs)/PMMA/indium tin oxide (ITO) electrically/optically tunable biomemristors were fabricated using the egg protein as a dielectric layer. The electrons in the GQDs were injected from the quantum dots into the dielectric layer or into the adjacent quantum dots under the excitation of light, and the EA–GQDs dielectric layer formed a pathway composed of GQDs for electronic transmission. The device successfully performed nine brain synaptic functions: excitatory postsynaptic current (EPSC), paired-pulse facilitation (PPF), short-term potentiation (STP), short-term depression (STD), the transition from short-term plasticity to long-term plasticity, spike-timing-dependent plasticity (STDP), spike-rate-dependent plasticity (SRDP), the process of learning, forgetting, and relearning, and Pavlov associative memory under UV light stimulation. The successful simulation of the synaptic behavior of this device provides the possibility for biomaterials to realize neuromorphic computing.
Interactions between Multiple Organs and Nutritional Metabolism in the Development and Progression of Metabolic Dysfunction-Associated Steatotic Liver Disease
Authors: Yoneda Masato , Nakajima Atsushi
Published: November 2023

Steatotic liver disease (SLD) is a condition characterized by an accumulation of fat in the liver [...]
Non-Response of Epstein–Barr Virus-Associated Breast Cancer after Primary Chemotherapy: Report of Two Cases
Authors: Gutjahr Ewgenija , Fremd Carlo , Arnscheidt Johanna , Penzel Roland , Wacker Jürgen , Sinn Peter
Published: November 2023

Based on epidemiological evidence and molecular findings, a possible association of Epstein–Barr virus (EBV) with the carcinogenesis of breast cancer has been described. However, the frequency of EBV in breast cancer and the role of EBV regarding tumor progression or therapeutic results is largely unexplored. Here, we report on two cases of advanced, lymph node-positive invasive breast cancer of no special type (NST), histologically showing no clinical or histological evidence of tumor regression as an equivalent of a lack of response to primary systemic therapy. Both tumors were considered to be EBV-associated due to their positivity in EBV-encoded RNA (EBER) in situ hybridization (ISH) and their immunoreactivity against EBV Epstein–Barr nuclear antigen 1 (EBNA1). We hypothesize that the unusual non-response to chemotherapy in these cases of breast cancer classified as triple-negative and HER2-positive may be linked to the EBV co-infection of tumor cells. Therefore, EBV tumor testing should be considered in patients with breast cancer presenting with resistance to chemotherapy. This hypothesis may provide a new aspect in the context of EBV-associated mechanisms of tumor progression.
A Virus-like Particle-Based F4 Enterotoxigenic Escherichia coli Vaccine Is Inhibited by Maternally Derived Antibodies in Piglets but Generates Robust Responses in Sows
Authors: Aves Kara-Lee , Guerra Priscila R. , Fresno Ana H. , Saraiva Mauro M. S. , Cox Eric , Bækbo Poul J. , Nielsen Morten A. , Sander Adam F. , Olsen John E.
Published: November 2023

F4-positive enterotoxigenic Escherichia coli is associated with diarrhea and poor growth outcomes in neonatal and newly weaned piglets and is thus a major economic and welfare burden in the swine industry. Vaccination of sows with F4 fimbriae protects against the neonatal disease via passive transfer of maternal immunity. However, this strategy does not protect against infection post-weaning. Consequently, prevention and treatment methods in weaner pigs heavily rely on the use of antimicrobials. Therefore, in order to reduce antimicrobial consumption, more effective prophylactic alternatives are needed. In this study, we describe the development of a capsid virus-like particle (cVLP)-based vaccine targeting the major F4 fimbriae subunit and adhesion molecule, FaeG, and evaluate its immunogenicity in mice, piglets, and sows. cVLP-display significantly increased systemic and mucosal antibody responses towards the recombinant FaeG antigen in mice models. However, in piglets, the presence of anti-F4 maternally derived antibodies severely inhibited the induction of active humoral responses towards the FaeG antigen. This inhibition could not be overcome, even with the enhanced immunogenicity achieved via cVLP display. However, in sows, intramuscular vaccination with the FaeG.cVLP vaccine was able to generate robust IgG and IgA responses that were comparable with a commercial fimbriae-based vaccine, and which were effectively transferred to piglets via colostrum intake. These results demonstrate that cVLP display has the potential to improve the systemic humoral responses elicited against low-immunogenic antigens in pigs; however, this effect is dependent on the use of antigens, which are not the targets of pre-existing maternal immunity.
Design, Synthesis, Molecular Modeling and Biological Evaluation of Novel Pyrazole Benzimidazolone Derivatives as Potent Antioxidants
Authors: Adardour Mohamed , Ait Lahcen Marouane , Oubahmane Mehdi , Ettahiri Walid , Hdoufane Ismail , Bouamama Hafida , Alanazi Mohammed M. , Cherqaoui Driss , Taleb Mustapha , Garcia Elena Zaballos , Baouid Abdesselam
Published: November 2023

In the present study, we used benzimidazolone as a starting material to efficiently synthesize several hybrid compounds of pyrazole benzimidazolone derivatives by the 1,3-dipolar cycloaddition reaction. These compounds were obtained in average yields and were characterized by NMR (1H and 13C) and HRMS analysis. The antioxidant activity of the synthesized compounds 5(a–c) and 6(a–c) was evaluated using in vitro reduction assays, including ferric reducing antioxidant power (FRAP) and total antioxidant capacity (TAC). The results indicated that products 5c, 6b, and 6c exhibit higher antioxidant activity compared to the reference compounds and showed a remarkable ability to effectively remove the radical at IC50 (14.00 ± 0.14, 12.47± 0.02, and 12.82 ± 0.10 µM, respectively) under the TAC assessment. Conversely, compound 6c showed excellent activity at IC50 (68.97 ± 0.26 µM) in the FRAP assay. We carried out molecular docking and dynamics simulations to investigate the binding mode and stability of 5c, 6b, and 6c in the active site of human Peroxiredoxin 5. An ADMET study was conducted to determine the drug properties of the synthesized compounds.
Mesoporous Silica Nanoparticles: Types, Synthesis, Role in the Treatment of Alzheimer’s Disease, and Other Applications
Authors: Sivamaruthi Bhagavathi Sundaram , Kapoor Devesh U. , Kukkar Rajiv R. , Gaur Mansi , Elossaily Gehan M. , Prajapati Bhupendra G. , Chaiyasut Chaiyavat
Published: November 2023

Globally, many individuals struggle with Alzheimer’s disease (AD), an unrelenting and incapacitating neurodegenerative condition. Despite notable research endeavors, effective remedies for AD remain constrained, prompting the exploration of innovative therapeutic avenues. Within this context, silica-based nanoplatforms have emerged with pronounced potential due to their unique attributes like expansive surface area, customizable pore dimensions, and compatibility with living systems. These nanoplatforms hold promise as prospective interventions for AD. This assessment provides a comprehensive overview encompassing various forms of mesoporous silica nanoparticles (MSNs), techniques for formulation, and their applications in biomedicine. A significant feature lies in their ability to precisely guide and control the transport of therapeutic agents to the brain, facilitated by the adaptability of these nanoplatforms as drug carriers. Their utility as tools for early detection and monitoring of AD is investigated. Challenges and prospects associated with harnessing MSNs are studied, underscoring the imperative of stringent safety evaluations and optimization of how they interact with the body. Additionally, the incorporation of multifunctional attributes like imaging and targeting components is emphasized to enhance their efficacy within the intricate milieu of AD. As the battle against the profound repercussions of AD persists, MSNs emerge as a promising avenue with the potential to propel the development of viable therapeutic interventions.
Novel Iron-Chelating Prodrug Significantly Enhanced Fluorescence-Mediated Detection of Glioma Cells Experimentally In Vitro
Authors: Reburn Charlotte , Gawthorpe George , Perry Alexis , Wood Mark , Curnow Alison
Published: November 2023

(1) Background: The protoporphyrin IX (PpIX)-mediated fluorescence-guided resection and interoperative photodynamic therapy (PDT) of remaining cells may be effective adjuvants to the resection of glioma. Both processes may be enhanced by increasing intracellular PpIX concentrations, which can be achieved through iron chelation. AP2-18 is a novel combinational drug, which ester-links a PpIX precursor (aminolaevulinic acid; ALA) to an iron-chelating agent (CP94). (2) Methods: Human glioma U-87 MG cells were cultured in 96-well plates for 24 h and incubated for 3 or 6 h with various test compound combinations: ALA (±) CP94, methyl aminolevulinate (MAL) (±) CP94 and AP2-18. PpIX fluorescence was measured at 0, 3 or 6 h with a Bio-tek Synergy HT plate reader, as well as immediately after irradiation with a 635 nm red light (Aktilite CL16 LED array), representing the PDT procedure. Cell viability post-irradiation was assessed using the neutral red assay. (3) Results: AP2-18 significantly increased PpIX fluorescence compared to all other test compounds. All treatment protocols effectively achieved PDT-induced cytotoxicity, with no significant difference between test compound combinations. (4) Conclusions: AP2-18 has potential to improve the efficacy of fluorescence-guided resection either with or without the subsequent intraoperative PDT of glioma. Future work should feature a more complex in vitro model of the glioma microenvironment.
A One-Dimensional Dynamic Constitutive Modeling of Ethylene Vinyl Acetate (EVA) Foam
Authors: Wu Jin , Lu Fude , Chen Jiaxuan , Wang Mingqi
Published: November 2023

Ethylene vinyl acetate copolymer (EVA) is good for impact protection and energy absorption, and belongs to rate sensitive-dependent materials. This study aimed to investigate the influence of increased strain rate and the presence of entrapped air on the enhancement of foam material strength. The compression deformation behavior of EVA foams containing a microporous structure was extensively investigated over different strain rates of 0.0017/s, 0.033/s, and 0.17/s, where each test was conducted at a constant compression velocity. A one-dimensional dynamic constitutive model was established to describe the large deformation response of EVA to different strain rates. The model included two components, the material action part and the air pressure part. Quasi-static and dynamic compression tests were used to determine the constitutive relations of three parameters, a1, a2, and the leaking rate δ·. The samples with EVA foams at different strain rates were fitted using ORIGIN software, and the constitutive model parameters were obtained. It was found that the ratio of the air leaking rate to the strain rate gradually decreases, causing air within the EVA to be trapped in the cells rather than escaping in a timely manner with increasing strain rates.
Degradation and Stabilization of Polymer Materials
Authors: Mušič Branka , Sever Škapin Andrijana
Published: November 2023

The growing awareness of the consequences of climate change has prompted the formulation of policies and regulations to foster sustainability [...]
3D Printing of Flexible Mechanical Metamaterials: Synergistic Design of Process and Geometric Parameters
Authors: Li Nan , Xue Chenhao , Chen Shenggui , Aiyiti Wurikaixi , Khan Sadaf Bashir , Liang Jiahua , Zhou Jianping , Lu Bingheng
Published: November 2023

Mechanical metamaterials with ultralight and ultrastrong mechanical properties are extensively employed in various industrial sectors, with three-periodic minimal surface (TPMS) structures gaining significant research attention due to their symmetry, equation-driven characteristics, and exceptional mechanical properties. Compared to traditional lattice structures, TPMS structures exhibit superior mechanical performance. The mechanical properties of TPMS structures depend on the base material, structural porosity (volume fraction), and wall thickness. Hard rigid lattice structures such as Gyroid, diamond, and primitive exhibit outstanding performance in terms of elastic modulus, energy absorption, heat dissipation, and heat transfer. Flexible TPMS lattice structures, on the other hand, offer higher elasticity and recoverable large deformations, drawing attention for use in applications such as seat cushions and helmet impact-absorbing layers. Conventional fabrication methods often fail to guarantee the quality of TPMS structure samples, and additive manufacturing technology provides a new avenue. Selective laser sintering (SLS) has successfully been used to process various materials. However, due to the layer-by-layer manufacturing process, it cannot eliminate the anisotropy caused by interlayer bonding, which impacts the mechanical properties of 3D-printed parts. This paper introduces a process data-driven optimization design approach for TPMS structure geometry by adjusting volume fraction gradients to overcome the elastic anisotropy of 3D-printed isotropic lattice structures. Experimental validation and analysis are conducted using TPMS structures fabricated using TPU material via SLS. Furthermore, the advantages of volume fraction gradient-designed TPMS structures in functions such as energy absorption and heat dissipation are explored.
Innovative Approaches to Enhance Activity of Endogenous Olive Enzymes—A Model System Experiment: Part II—Non-Thermal Technique
Authors: Kraljić Klara , Balbino Sandra , Filipan Katarina , Herceg Zoran , Stuparević Igor , Ivanov Mia , Vukušić Pavičić Tomislava , Jakoliš Niko , Škevin Dubravka
Published: November 2023

The aim of this study was to determine the optimal parameters of pulsed electric field treatment to increase the activity of β-glucosidase and lipoxygenase, crucial enzymes that improve the nutritional quality and sensory properties of virgin olive oils. The activity of the enzymes was determined spectrophotometrically immediately after treatment of model systems (commercial enzymes and their substrates) with pulsed electric fields and after simulation of the malaxation process for 30 min at 25 °C. Pulsed electric field treatments were performed with electric field strengths of 2.67 and 13.33 kV/cm at frequencies of 25 and 125 Hz for 1, 2, and 5 min. The results showed a positive correlation of β-glucosidase activity with the electric field strength and time, with the first of the two factors having the greatest influence. Lipoxygenase activity was affected only by the duration of treatment: positively immediately after treatment and negatively after simulation of the malaxation process. Based on these results, pretreatment with a moderate pulsed electric field for 2 min before the malaxation process could be proposed to increase the activity of β-glucosidase and lipoxygenase, e.g., for the production of virgin olive oils with higher concentrations of polyphenols and desirable volatile compounds.
Introduction of Special Issue “Phenomenology and Systematic Theology”
Authors: Dahl Espen , Rolfsen Theodor
Published: November 2023

For over a century, phenomenology has been a major philosophical movement [...]
A New Approach to the Spatialization of Religion: Changes in the Spatial Distribution of Religious Institutions in Debrecen (Hungary) between the Second Half of the Nineteenth Century and 2023
Authors: Kozma Gábor , Czimre Klára , Balcsók István , Pénzes János , Makhanov Kanat
Published: November 2023

The aim of the article is to examine one of the neglected areas in the spatiality of religion, the spatial distribution of religious institutions and the changes that have taken place in this relation over time in the case of Debrecen, a specific city in Hungary, which has hosted several religions both in the past and present. The main findings are discussed in five subsections concentrating on five consecutive periods. During the period under study, the number of institutions run by churches increased steadily until the Second World War. This process was interrupted after the Second World War, and partly as a consequence of the world war (with the deportation of Jews to concentration camps) and partly due to the anti-religious nature of the socialist regime, there was a significant decline followed by a resumption of expansion after 1990. Regarding the location of the institutions within the city and its changes, there were significant differences between the various types of institutions (e.g., churches, administrative centres, kindergartens, elementary and grammar schools). Research primarily relied on document analysis and fieldwork.
High-Resolution PM2.5 Concentrations Estimation Based on Stacked Ensemble Learning Model Using Multi-Source Satellite TOA Data
Authors: Fu Qiming , Guo Hong , Gu Xingfa , Li Juan , Zhang Wenhao , Mi Xiaofei , Zhao Qichao , Chen Debao
Published: November 2023

Nepal has experienced severe fine particulate matter (PM2.5) pollution in recent years. However, few studies have focused on the distribution of PM2.5 and its variations in Nepal. Although many researchers have developed PM2.5 estimation models, these models have mainly focused on the kilometer scale, which cannot provide accurate spatial distribution of PM2.5 pollution. Based on Gaofen-1/6 and Landsat-8/9 satellite data, we developed a stacked ensemble learning model (named XGBLL) combined with meteorological data, ground PM2.5 concentrations, ground elevation, and population data. The model includes two layers: a XGBoost and Light GBM model in the first layer, and a linear regression model in the second layer. The accuracy of XGBLL model is better than that of a single model, and the fusion of multi-source satellite remote sensing data effectively improves the spatial coverage of PM2.5 concentrations. Besides, the spatial distribution of the daily mean PM2.5 concentrations in the Kathmandu region under different air conditions was analyzed. The validation results showed that the monthly averaged dataset was accurate (R2 = 0.80 and root mean square error = 7.07). In addition, compared to previous satellite PM2.5 datasets in Nepal, the dataset produced in this study achieved superior accuracy and spatial resolution.