bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical Simulation of the Effect of Freeze-Thaw Cycles on the Axial Compression Strength of Rubber Concrete
Authors: Hao Dingyi , Huang Xiaoyu , Li Houmin , Cao Zhou , Yang Zijiang , Pei Xianfeng , Min Kai , Liu Cai , Li Wenchao , Zhang En , Shen Jie
Published: June 2023

The incorporation of rubber can enhance concrete’s durability and effectively reduce the damage caused by freeze-thaw cycling (FTC). Still, there has been only limited research on the damage mechanism of RC at the fine view level. To gain insight into the expansion process of uniaxial compression damage cracks in rubber concrete (RC) and summarize the internal temperature field distribution law during FTC, a fine RC thermodynamic model containing mortar, aggregate, rubber, water, and interfacial transition zone (ITZ) is established in this paper, and the cohesive element is selected for the ITZ part. The model can be used to study the mechanical properties of concrete before and after FTC. The validity of the calculation method was verified by comparing the calculated results of the compressive strength of concrete before and after FTC with the experimental results. On this basis, this study analyzed the compressive crack extension and internal temperature distribution of RC at 0, 5, 10, and 15% replacement rates before and after 0, 50, 100, and 150 cycles of FTC. The results showed that the fine-scale numerical simulation method can effectively reflect the mechanical properties of RC before and after FTC, and the computational results verify the applicability of the method to rubber concrete. The model can effectively reflect the uniaxial compression cracking pattern of RC before and after FTC. Incorporating rubber can impede temperature transfer and reduce the compressive strength loss caused by FTC in concrete. The FTC damage to RC can be reduced to a greater extent when the rubber incorporation is 10%.
Comparison of Surface Morphology and Tool Wear in the Machining of Ti-6Al-4V Alloys with Uncoated and TiAlN Tools under Dry, Minimum Quantity Lubrication, Flood Cooling, and Low-Temperature Spray Jet Cooling Conditions
Authors: Zhao Jinfu , Liu Zhanqiang , Gong Zipeng , Liu Annan , Cai Yukui , Wang Bing , Song Qinghua , Liang Xiaoliang , Zhang Yanbin , Zhang Zhicheng , Ji Haiyang
Published: June 2023

TiAlN-coated carbide tools have been used to machine Ti-6Al-4V alloys in aviation workshops. However, the effect of TiAlN coating on surface morphology and tool wear in the processing of Ti-6Al-4V alloys under various cooling conditions has not been reported in the public published literature. In our current research, turning experiments of Ti-6Al-4V with uncoated and TiAlN tools under dry, MQL, flood cooling, and cryogenic spray jet cooling conditions were carried out. The machined surface roughness and tool life were selected as the two main quantitative indexes for estimating the effects of TiAlN coating on the cutting performance of Ti-6Al-4V under various cooling conditions. The results showed that TiAlN coating makes it hard to improve the machined surface roughness and tool wear of a cutting titanium alloy at a low speed of 75 m/min compared to that achieved by uncoated tools. The TiAlN tools presented excellent tool life in turning Ti-6Al-4V at a high speed of 150 m/min compared to that achieved by uncoated tools. From the perspective of obtaining finished surface roughness and superior tool life in high-speed turning Ti-6Al-4V, the selection of TiAlN tools is feasible and reasonable under the cryogenic spray jet cooling condition. The dedicative results and conclusions of this research could guide the optimized selection of cutting tools in machining Ti-6Al-4V for the aviation industry.
Thermo-Mechanical Fluid–Structure Interaction Numerical Modelling and Experimental Validation of MEMS Electrothermal Actuators for Aqueous Biomedical Applications
Authors: Sciberras Thomas , Demicoli Marija , Grech Ivan , Mallia Bertram , Mollicone Pierluigi , Sammut Nicholas
Published: June 2023

Recent developments in MEMS technologies have made such devices attractive for use in applications that involve precision engineering and scalability. In the biomedical industry, MEMS devices have gained popularity in recent years for use as single-cell manipulation and characterisation tools. A niche application is the mechanical characterisation of single human red blood cells, which may exhibit certain pathological conditions that impart biomarkers of quantifiable magnitude that are potentially detectable via MEMS devices. Such applications come with stringent thermal and structural specifications wherein the potential device candidates must be able to function with no exceptions. This work presents a state-of-the-art numerical modelling methodology that is capable of accurately predicting MEMS device performance in various media, including aqueous ones. The method is strongly coupled in nature, whereby thermal as well as structural degrees of freedom are transferred to and from finite element and finite volume solvers at every iteration. This method therefore provides MEMS design engineers with a reliable tool that can be used in design and development stages and helps to avoid total reliability on experimental testing. The proposed numerical model is validated via a series of physical experiments. Four MEMS electrothermal actuators with cascaded V-shaped drivers are presented. With the use of the newly proposed numerical model as well as the experimental testing, the MEMS devices’ suitability for biomedical applications is confirmed.
Genetics: A Starting Point for the Prevention and the Treatment of Obesity
Authors: Novelli Giuseppe , Cassadonte Carmen , Sbraccia Paolo , Biancolella Michela
Published: June 2023

Obesity is a common, serious, and costly disease. More than 1 billion people worldwide are obese—650 million adults, 340 million adolescents, and 39 million children. The WHO estimates that, by 2025, approximately 167 million people—adults and children—will become less healthy because they are overweight or obese. Obesity-related conditions include heart disease, stroke, type 2 diabetes, and certain types of cancer. These are among the leading causes of preventable, premature death. The estimated annual medical cost of obesity in the United States was nearly $173 billion in 2019 dollars. Obesity is considered the result of a complex interaction between genes and the environment. Both genes and the environment change in different populations. In fact, the prevalence changes as the result of eating habits, lifestyle, and expression of genes coding for factors involved in the regulation of body weight, food intake, and satiety. Expression of these genes involves different epigenetic processes, such as DNA methylation, histone modification, or non-coding micro-RNA synthesis, as well as variations in the gene sequence, which results in functional alterations. Evolutionary and non-evolutionary (i.e., genetic drift, migration, and founder’s effect) factors have shaped the genetic predisposition or protection from obesity in modern human populations. Understanding and knowing the pathogenesis of obesity will lead to prevention and treatment strategies not only for obesity, but also for other related diseases.
Periodontal Disease and Other Adverse Health Outcomes Share Risk Factors, including Dietary Factors and Vitamin D Status
Authors: Grant William B. , van Amerongen Barbara M. , Boucher Barbara J.
Published: June 2023

For nearly a century, researchers have associated periodontal disease (PD) with risks of other adverse health outcomes such as cardiovascular disease, diabetes mellitus, and respiratory diseases, as well as adverse pregnancy outcomes. Those findings have led to the hypothesis that PD causes those adverse health outcomes either by increasing systemic inflammation or by the action of periodontopathic bacteria. However, experiments largely failed to support that hypothesis. Instead, the association is casual, not causal, and is due to shared underlying modifiable risk factors, including smoking, diet, obesity, low levels of physical activity, and low vitamin D status. Diabetes mellitus is also considered a risk factor for PD, whereas red and processed meat are the most important dietary risk factors for diabetes. Because PD generally develops before other adverse health outcomes, a diagnosis of PD can alert patients that they could reduce the risk of adverse health outcomes with lifestyle changes. In addition, type 2 diabetes mellitus can often be reversed rapidly by adopting an anti-inflammatory, nonhyperinsulinemic diet that emphasizes healthful, whole plant-based foods. This review describes the evidence that proinflammatory and prohyperinsulinemia diets and low vitamin D status are important risk factors for PD and other adverse health outcomes. We also make recommendations regarding dietary patterns, food groups, and serum 25-hydroxyvitamin D concentrations. Oral health professionals should routinely inform patients with PD that they could reduce their risk of severe PD as well as the risks of many other adverse health outcomes by making appropriate lifestyle changes.
Body Composition in Fussy-Eating Children, with and without Neurodevelopmental Disorders, and Their Parents, Following a Taste Education Intervention
Authors: Thorsteinsdottir Sigrun , Bjarnason Ragnar , Eliasdottir Helga G. , Olafsdottir Anna S.
Published: June 2023

Fussy eaters may have an increased risk of becoming overweight or obese as adolescents, with fussy eating and weight status also correlating with neurodevelopmental disorders (NDs) such as autism spectrum disorder (ASD) and attention deficit/hyperactivity disorder (ADHD). Further, maternal and children’s weight status relationships are well-established. In this study, we analyzed the body composition of parent–child dyads using bioelectrical impedance analysis (BIA). Fifty-one children aged 8–12 years, with an ND (n = 18) and without (n = 33), and their parents, participated in a 7-week food-based Taste Education intervention with 6-month follow-up. The paired t-test was used to compare differences in body composition based on children’s ND status. In logistic regression analysis, odds of children being in the overweight/obese or overfat/obese categories increased by a factor of 9.1 and 10.6, respectively, when having NDs, adjusting for parents’ BMI (body mass index) or fat percentage (FAT%). Children with NDs and their parents had significantly higher mean BMI-SDS (BMI standard deviation score) and FAT% at pre-intervention than children without NDs and their parents. Mean BMI-SDS and FAT% lowered significantly between time points for children with NDs and their parents but not for children without NDs or their parents. The findings underline the need for additional exploration into the relationships between children’s and parents’ body composition based on children’s ND status.
Effectiveness of Theory-Based Physical Activity and Nutrition Interventions in Aging Latino Adults: A Scoping Review
Authors: Maafs-Rodríguez Ana , Folta Sara C.
Published: June 2023

In the United States (US), Latino individuals older than 50 years face health disparities compared to their White counterparts. Considering the rising life expectancy and the projected increase of older Latino adults in the US, this scoping review aimed to determine the effectiveness of theory-based and culturally relevant strategies that promote healthy aging in Latinos. Web of Science and PubMed databases were searched between December 2022 and February 2023 for peer-reviewed articles assessing healthy aging interventions tailored to community-dwelling aging Latino adults. We included nine studies describing the effects of seven interventions on physical activity- or nutrition-related outcomes. Although not always statistically significant, interventions had a beneficial impact on well-being indicators. The most commonly used behavioral theories were Social Cognitive Theory and Attribution Theory. Latino cultural elements in these studies included partnering with community organizations that serve Latinos (such as Catholic churches), delivery of in-person bilingual group sessions by trusted community members (such as promotoras or Latino dance instructors), and incorporating values such as family and religion into the health curriculum, among others. Future strategies that promote healthy aging in Latino adults should proactively culturally adapt the theoretical foundations and the design, recruitment, and implementation processes to ensure their relevance and effectiveness.
The Role of AI in Drug Discovery: Challenges, Opportunities, and Strategies
Authors: Blanco-González Alexandre , Cabezón Alfonso , Seco-González Alejandro , Conde-Torres Daniel , Antelo-Riveiro Paula , Piñeiro Ángel , Garcia-Fandino Rebeca
Published: June 2023

Artificial intelligence (AI) has the potential to revolutionize the drug discovery process, offering improved efficiency, accuracy, and speed. However, the successful application of AI is dependent on the availability of high-quality data, the addressing of ethical concerns, and the recognition of the limitations of AI-based approaches. In this article, the benefits, challenges, and drawbacks of AI in this field are reviewed, and possible strategies and approaches for overcoming the present obstacles are proposed. The use of data augmentation, explainable AI, and the integration of AI with traditional experimental methods, as well as the potential advantages of AI in pharmaceutical research, are also discussed. Overall, this review highlights the potential of AI in drug discovery and provides insights into the challenges and opportunities for realizing its potential in this field. Note from the human authors: This article was created to test the ability of ChatGPT, a chatbot based on the GPT-3.5 language model, in terms of assisting human authors in writing review articles. The text generated by the AI following our instructions (see Supporting Information) was used as a starting point, and its ability to automatically generate content was evaluated. After conducting a thorough review, the human authors practically rewrote the manuscript, striving to maintain a balance between the original proposal and the scientific criteria. The advantages and limitations of using AI for this purpose are discussed in the last section.
Cyclic Peptides with Antifungal Properties Derived from Bacteria, Fungi, Plants, and Synthetic Sources
Authors: Helmy Naiera M. , Parang Keykavous
Published: June 2023

Fungal infections remain a significant concern for human health. The emergence of microbial resistance, the improper use of antimicrobial drugs, and the need for fewer toxic antifungal treatments in immunocompromised patients have sparked substantial interest in antifungal research. Cyclic peptides, classified as antifungal peptides, have been in development as potential antifungal agents since 1948. In recent years, there has been growing attention from the scientific community to explore cyclic peptides as a promising strategy for combating antifungal infections caused by pathogenic fungi. The identification of antifungal cyclic peptides from various sources has been possible due to the widespread interest in peptide research in recent decades. It is increasingly important to evaluate narrow- to broad-spectrum antifungal activity and the mode of action of synthetic and natural cyclic peptides for both synthesized and extracted peptides. This short review aims to highlight some of the antifungal cyclic peptides isolated from bacteria, fungi, and plants. This brief review is not intended to present an exhaustive catalog of all known antifungal cyclic peptides but rather seeks to showcase selected cyclic peptides with antifungal properties that have been isolated from bacteria, fungi, plants, and synthetic sources. The addition of commercially available cyclic antifungal peptides serves to corroborate the notion that cyclic peptides can serve as a valuable source for the development of antifungal drugs. Additionally, this review discusses the potential future of utilizing combinations of antifungal peptides from different sources. The review underscores the need for the further exploration of the novel antifungal therapeutic applications of these abundant and diverse cyclic peptides.
Evaluation of the In Vitro Antimicrobial Efficacy against Staphylococcus aureus and epidermidis of a Novel 3D-Printed Degradable Drug Delivery System Based on Polycaprolactone/Chitosan/Vancomycin—Preclinical Study
Authors: López-González Iván , Hernández-Heredia Ana Belén , Rodríguez-López María Isabel , Auñón-Calles David , Boudifa Mohamed , Gabaldón José Antonio , Meseguer-Olmo Luis
Published: June 2023

Acute and chronic bone infections, especially those caused by methicillin-resistant Staphylococcus aureus (MRSA), remains a major complication and therapeutic challenge. It is documented that local administration of vancomycin offers better results than the usual routes of administration (e.g., intravenous) when ischemic areas are present. In this work, we evaluate the antimicrobial efficacy against S. aureus and S. epidermidis of a novel hybrid 3D-printed scaffold based on polycaprolactone (PCL) and a chitosan (CS) hydrogel loaded with different vancomycin (Van) concentrations (1, 5, 10, 20%). Two cold plasma treatments were used to improve the adhesion of CS hydrogels to the PCL scaffolds by decreasing PCL hydrophobicity. Vancomycin release was measured by means of HPLC, and the biological response of ah-BM-MSCs growing in the presence of the scaffolds was evaluated in terms of cytotoxicity, proliferation, and osteogenic differentiation. The PCL/CS/Van scaffolds tested were found to be biocompatible, bioactive, and bactericide, as demonstrated by no cytotoxicity (LDH activity) or functional alteration (ALP activity, alizarin red staining) of the cultured cells and by bacterial inhibition. Our results suggest that the scaffolds developed would be excellent candidates for use in a wide range of biomedical fields such as drug delivery systems or tissue engineering applications.
Expanding the Availability of Onasemnogene Abeparvovec to Older Patients: The Evolving Treatment Landscape for Spinal Muscular Atrophy
Authors: René Charlotte A. , Parks Robin J.
Published: June 2023

Spinal muscular atrophy (SMA) is a devastating neuromuscular disorder caused by mutations in the survival of motor neuron 1 (SMN1) gene, which leads to a reduced level in the SMN protein within cells. Patients with SMA suffer from a loss of alpha motor neurons in the spinal cord leading to skeletal muscle atrophy in addition to deficits in other tissues and organs. Patients with severe forms of the disease require ventilator assistance and typically succumb to the disease due to respiratory failure. Onasemnogene abeparvovec is an adeno-associated virus (AAV)-based gene therapeutic that has been approved for infants and young children with SMA, and it is delivered through intravenous administration using a dose based on the weight of the patient. While excellent outcomes have been observed in treated patients, the greater viral dose necessary to treat older children and adults raises legitimate safety concerns. Recently, onasemnogene abeparvovec use was investigated in older children through a fixed dose and intrathecal administration, a route that provides a more direct delivery to affected cells in the spinal cord and central nervous system. The promising results observed in the STRONG trial may support approval of onasemnogene abeparvovec for a greater proportion of patients with SMA.
Preparation and In Vitro Characterization of Microneedles Containing Inclusion Complexes Loaded with Progesterone
Authors: He Hongji , Wang Zhaozhi , Aikelamu Kadireya , Bai Jingya , Shen Qi , Gao Xiaoli , Wang Mei
Published: June 2023

Objective: In order to improve patient compliance and the ease of use during progesterone application, and to increase the clinical application of progesterone, progesterone was made into a microneedle. Methods: Progesterone complexes were prepared using a single-factor and central composite design. In the preparation of the microneedles, the tip loading rate was used as an evaluation index. The selection of tip materials among the biocompatible materials of gelatin (GEL), hyaluronic acid (HA), and polyvinylpyrrolidone (PVP), and the use of polyvinyl alcohol (PVA) and hydroxypropyl cellulose (HPC) as backing layers, respectively, were carried out and the resulting microneedles were evaluated accordingly. Results: The progesterone inclusion complexes prepared at a molar ratio of 1:2.16 progesterone and hydroxypropyl-β-cyclodextrin (HP-β-CD), a temperature of 50 °C, and reaction time of 4 h had high encapsulation and drug-loading capacities of 93.49% and 9.55%, respectively. Gelatine was finally chosen as the material for the preparation of the micro-needle tip based on the drug loading rate of the tip. Two types of microneedles were prepared: one with 7.5% GEL as the tip and 50% PVA as the backing layer, and one with 15% GEL as the tip and 5% HPC as the backing layer. The microneedles of both prescriptions exhibited good mechanical strength and penetrated the skin of rats. The needle tip loading rates were 49.13% for the 7.5% GEL-50% PVA microneedles and 29.31% for the 15% GEL-5% HPC microneedles. In addition, in vitro release and transdermal experiments were performed using both types of microneedles. Conclusion: The microneedles prepared in this study enhanced the in vitro transdermal amount of progesterone drug by releasing the drug from the microneedle tip into the subepidermis.
Epoxidized Soybean-Oils-Based Pressure-Sensitive Adhesives with Di-Hydroxylated Soybean-Oils Copolymerizing and Antioxidant Grafting
Authors: Kuang Yongyan , Li Wenlong , Xie Shuli , Gong Weijian , Ye Zihan , Wang Yiming , Peng Dan , Li Jun
Published: June 2023

Vegetable-oils-based pressure-sensitive adhesives (PSAs) are being developed as a substitute for petrochemical-based PSAs for application in daily life. However, vegetable-oils-based PSAs face the problems of unsatisfactory binding strengths and easy aging. In this work, the grafting of antioxidants (tea polyphenol palmitates, caffeic acid, ferulic acid, gallic acid, butylated hydroxytoluene, tertiary butylhydroquinone, butylated hydroxyanisole, propyl gallate (PG), tea polyphenols) was introduced into an epoxidized soybean oils (ESO)/di-hydroxylated soybean oils (DSO)-based PSA system to improve the binding strengths and aging-resistant properties. PG was screened out as the most suitable antioxidant in the ESO/DSO-based PSA system. Under optimal conditions (ESO/DSO mass ratio of 9/3, 0.8% PG, 55% rosin ester (RE), 8% phosphoric acid (PA), 50 °C, and 5 min), the peel adhesion, tack, and shear adhesion of the PG-grafted ESO/DSO-based PSA increased to 1.718 N/cm, 4.62 N, and >99 h, respectively, in comparison with the control (0.879 N/cm, 3.59 N, and 13.88 h), while peel adhesion residue reduced to 12.16% in comparison with the control (484.07%). The thermal stability of the ESO/DSO-based PSA was enhanced after PG grafting. PG, RE, PA, and DSO were partially crosslinked in the PSA system, with the rest being free in the network structures. Thus, antioxidant grafting is a feasible method for improving the binding strengths and aging-resistant properties of vegetable-oils-based PSAs.
Effect of Strain Rate on Tensile Properties of Carbon Fiber-Reinforced Epoxy Laminates with Different Stacking Sequences and Ply Orientations
Authors: Gao Donglin , Bao Zuguo , Han Weijian , Wang Xianpeng , Huang Shiyao , Huang Li , Chen Qiuren , Zhao Hailong , Xu Yahong
Published: June 2023

In practical application situations, a carbon fiber-reinforced polymer (CFRP) is often subjected to complex dynamic loadings. The effect of the strain rate on mechanical properties is very important for the CFRP design and product development. In this work, static and dynamic tensile properties of CFRP with different stacking sequences and ply orientations were investigated. The results showed that the tensile strengths of CFRP laminates were sensitive to the strain rate, while Young’s modulus was independent of the strain rate. Moreover, the strain rate effect was related to the stacking sequences and ply orientations. The experimental results showed that the strain rate effects of the cross-ply laminates and quasi-isotropic-ply laminates were lower than that of the unidirectional-ply laminates. Finally, the failure modes of CFRP laminates were investigated. Failure morphology demonstrated that the differences in strain rate effects among cross-ply laminates, quasi-isotropic-ply laminates, and unidirectional-ply laminates were caused by the mismatch between the fiber and the matrix when the strain rate increased.
Multi-Layered Composites of Natural Rubber (NR) and Bismuth Oxide (Bi2O3) with Enhanced X-ray Shielding and Mechanical Properties
Authors: Toyen Donruedee , Wimolmala Ekachai , Saenboonruang Kiadtisak
Published: June 2023

Due to rapid increases in the utilization of radiation and nuclear technologies, effective and suitable radiation-shielding materials have become one of the most sought-after options to protect users and the public from excessive exposure to the radiation. However, most radiation-shielding materials have greatly reduced mechanical properties after the addition of fillers, resulting in their limited useability and shortened lifetime. Therefore, this work aimed to alleviate such drawbacks/limitations by exploring a possible method to simultaneously enhance both the X-ray shielding and mechanical properties of bismuth oxide (Bi2O3)/natural rubber (NR) composites through multi-layered structures, with varying (1–5) layers and a total combined thickness of 10 mm. To correctly determine the effects of the multi-layered structures on the properties of NR composites, the formulation and layer configuration for all multi-layered samples were tailored such that their theoretical X-ray shielding properties were equal to those of a single-layered sample that contained 200 phr Bi2O3. The results indicated that the multi-layered Bi2O3/NR composites with neat NR sheets on both outer layers (sample-D, sample-F, sample-H, and sample-I) had noticeably higher tensile strength and elongation at break than those of the other designs. Furthermore, all multi-layered samples (sample-B to sample-I), regardless of the layer structure, had enhanced X-ray shielding properties compared to those with a single layer (sample-A), as shown by their higher values of the linear attenuation coefficient (µ) and lead equivalence (Pbeq) and the lower value of the half-value layer (HVL) in the former. This work also determined the effects of thermal aging on relevant properties for all samples, with the results revealing that all the thermal-aged composites had higher values for the tensile modulus but lower values for the swelling percentage, tensile strength, and elongation at break, compared with the non-aged composites. Hence, based on the overall outcomes from this work, it could be concluded that the worrisome decreases in mechanical properties of the common single-layered NR composites after the addition of Bi2O3 could be prevented/reduced by introducing appropriate multi-layered structures, which would not only widen potential applications but also prolong the lifetime of the composites.
Fracture Characteristics of Commercial PEEK Dental Crowns: Combining the Effects of Aging Time and TiO2 Content
Authors: Lu Wen-Ju , Chen Wei-Cheng , Srimaneepong Viritpon , Chen Chiang-Sang , Huang Chang-Hung , Lin Hui-Ching , Tung Oi-Hong , Huang Her-Hsiung
Published: June 2023

Polyetheretherketone (PEEK) is an emerging thermoplastic polymer with good mechanical properties and an elastic modulus similar to that of alveolar bone. PEEK dental prostheses for computer-aided design/computer-aided manufacturing (CAD/CAM) systems on the market often have additives of titanium dioxide (TiO2) to strengthen their mechanical properties. However, the effects of combining aging, simulating a long-term intraoral environment, and TiO2 content on the fracture characteristics of PEEK dental prostheses have rarely been investigated. In this study, two types of commercially available PEEK blocks, containing 20% and 30% TiO2, were used to fabricate dental crowns by CAD/CAM systems and were aged for 5 and 10 h based on the ISO 13356 specifications. The compressive fracture load values of PEEK dental crowns were measured using a universal test machine. The morphology and crystallinity of the fracture surface were analyzed by scanning electron microscopy and an X-ray diffractometer, respectively. Statistical analysis was performed using the paired t-test (α = 0.05). Results showed no significant difference in the fracture load value of the test PEEK crowns with 20% and 30% TiO2 after 5 or 10 h of aging treatment; all test PEEK crowns have satisfactory fracture properties for clinical applications. Fracture surface analysis revealed that all test crowns fractured from the lingual side of the occlusal surface, with the fracture extending along the lingual sulcus to the lingual edge, showing a feather shape at the middle part of the fracture extension path and a coral shape at the end of the fracture. Crystalline analysis showed that PEEK crowns, regardless of aging time and TiO2 content, remained predominantly PEEK matrix and rutile phase TiO2. We would conclude that adding 20% or 30% TiO2 to PEEK crowns may have been sufficient to improve the fracture properties of PEEK crowns after 5 or 10 h of aging. Aging times below 10 h may still be safe for reducing the fracture properties of TiO2-containing PEEK crowns.
In Situ Polymerization Synthesis of Graphdiyne Nanosheets as Electrode Material and Its Application in NMR Spectroelectrochemistry
Authors: Zhang Siyue , Yang Lin , Zhang Xiaoping , Chen Yuxue , Zhang Yutong , Sun Wei
Published: June 2023

In situ NMR spectroelectrochemistry is extremely powerful in studying redox reactions in real time and identifying unstable reaction intermediates. In this paper, in situ polymerization synthesis of ultrathin graphdiyne (GDY) nanosheets was realized on the surface of copper nanoflower/copper foam (nano−Cu/Cuf)-based electrode with hexakisbenzene monomers and pyridine. Palladium (Pd) nanoparticles were further deposited onto the GDY nanosheets by the constant potential method. By using this GDY composite as electrode material, a new NMR-electrochemical cell was designed for in situ NMR spectroelectrochemistry measurement. The three-electrode electrochemical system consists of a Pd/GDY/nano−Cu/Cuf electrode as the working electrode, a platinum wire as the counter electrode, and a silver/silver chloride (Ag/AgCl) wire as a quasi-reference electrode, which can be dipped into a specially constructed sample tube and adapted for convenient operation in any commercial high-field, variable-temperature FT NMR spectrometer. The application of this NMR-electrochemical cell is illustrated by monitoring the progressive oxidation of hydroquinone to benzoquinone by controlled-potential electrolysis in aqueous solution.
Research on the Analysis and Application of Polymer Materials in Contemporary Sculpture Art Creation
Authors: Gao Chao , Wang Feng , Hu Xiaobing , Zhang Ming
Published: June 2023

The application of polymer materials in sculpture art creation is extensive and plays a significant role in the development of sculpture art. This article aims to systematically explore the application of polymer materials in contemporary sculpture art creation. The research comprehensively applies various techniques such as literature research, data comparison, and case analysis to explore in detail the ways, methods, and paths of polymer materials employed in the shaping, decoration, and protection of sculptural artworks. First, the article analyzes three methods of shaping sculpture artworks with polymer materials (casting, printing, and constructing). Secondly, it explores two techniques of using polymer materials to adorn sculpture artworks (coloring and imitating texture); then it discusses the significant approach of using polymer materials to protect sculptural artworks (protective spray film). Finally, the research identifies the merits and demerits of using polymer materials in contemporary sculpture art creation. The findings of this study are expected to enrich the effective application of polymer materials in contemporary sculpture art creation and offer novel techniques and ideas for contemporary sculpture art creators.
Research on Hysteretic Behavior of FRP-Confined Concrete Core-Encased Rebar
Authors: Lu Jingzhou , Mou Tong , Wang Chen , Huang Han , Han Wenyu
Published: June 2023

FRP-confined concrete core-encased rebar (FCCC-R) is a novel composite structure that has recently been proposed to effectively delay the buckling of ordinary rebar and enhance its mechanical properties by utilizing high-strength mortar or concrete and an FRP strip to confine the core. The purpose of this study was to study the hysteretic behavior of FCCC-R specimens under cyclic loading. Different cyclic loading systems were applied to the specimens and the resulting test data were analyzed and compared, in addition to revealing the mechanism of elongation and mechanical properties of the specimens under the different loading systems. Furthermore, finite-element simulation was performed for different FCCC-Rs using the ABAQUS software. The finite-element model was also used for the expansion parameter studies to analyze the effects of different influencing factors, including the different winding layers, winding angles of the GFRP strips, and the rebar-position eccentricity, on the hysteretic properties of FCCC-R. The test result indicates that FCCC-R exhibits superior hysteretic properties in terms of maximum compressive bearing capacity, maximum strain value, fracture stress, and envelope area of the hysteresis loop when compared to ordinary rebar. The hysteretic performance of FCCC-R increases as the slenderness ratio is increased from 10.9 to 24.5 and the constraint diameter is increased from 30 mm to 50 mm, respectively. Under the two cyclic loading systems, the elongation of the FCCC-R specimens is greater than that of ordinary rebar specimens with the same slenderness ratio. For different slenderness ratios, the range of maximum elongation improvement is about 10% to 25%, though there is still a large discrepancy compared to the elongation of ordinary rebar under monotonic tension. Despite the maximum compressive bearing capacity of FCCC-R is improved under cyclic loading, the internal rebars are more prone to buckling. The results of the finite-element simulation are in good agreement with the experimental results. According to the study of expansion parameters, it is found that the hysteretic properties of FCCC-R increase as the number of winding layers (one, three, and five layers) and winding angles (30°, 45°, and 60°) in the GFRP strips increase, while they decrease as the rebar-position eccentricity (0.15, 0.22, and 0.30) increases.
‘Not-All-There’ in the Necropolis: Afterlife and Madness in Urban Novels
Authors: Spirkovska Marija
Published: June 2023

The paper takes its departure point from a seemingly innocuous idiom that common English parlance uses to describe a person who has lost possession of their rational mind: “not all there.” Interrogating the locality that this deictic “there” implies, the argument juxtaposes it with recent religious scholarship on the Afterlife, which posits that, by extension, from the absence of the risen Christ from the tomb, the Christian subject is essentially similarly ‘not there’. Thus, the paper treads a thin line between sacredness and profanity in attempting to map out the spatial coordinates and configuration of the imaginary realms of the life-less and mind-less, that is, the Afterlife and madness, respectively. This examination is conducted through late 20th-century literary representations of, on the one hand, the Afterlife as an urban netherworld, experienced as infernal and life-negating, and of the city perceived through a schizophrenic mind, which displays an uncanny similarity to Hell: disorienting, dissipating, and ghostly. In this manner, following recent scholarship of embodied cognition, the paper demonstrates an unexpected and hitherto unexplored affinity between the Afterlife as a key concept of conventional religious thought and madness and the mad subject as an oft-reviled cultural, social, and literary figure.
Implementation of Real-Time Space Target Detection and Tracking Algorithm for Space-Based Surveillance
Authors: Su Yueqi , Chen Xin , Liu Gaorui , Cang Chen , Rao Peng
Published: June 2023

Space-based target surveillance is important for aerospace safety. However, with the increasing complexity of the space environment, the stellar target and strong noise interference pose difficulties for space target detection. Simultaneously, it is hard to balance real-time processing with computational performance for the onboard processing platform owing to resource limitations. The heterogeneous multi-core architecture has corresponding processing capabilities, providing a hardware implementation platform with real-time and computational performance for space-based applications. This paper first developed a multi-stage joint detection and tracking model (MJDTM) for space targets in optical image sequences. This model combined an improved local contrast method and the Kalman filter to detect and track the potential targets and use differences in movement status to suppress the stellar targets. Then, a heterogeneous multi-core processing system based on a field-programmable gate array (FPGA) and digital signal processor (DSP) was established as the space-based image processing system. Finally, MJDTM was optimized and implemented on the above image processing system. The experiments conducted with simulated and actual image sequences examine the accuracy and efficiency of the MJDTM, which has a 95% detection probability while the false alarm rate is 10−4. According to the experimental results, the algorithm hardware implementation can detect targets in an image with 1024 × 1024 pixels in just 22.064 ms, which satisfies the real-time requirements of space-based surveillance.
Uncertainty of CYGNSS-Derived Heat Flux Variations at Diurnal to Seasonal Time Scales over the Tropical Oceans
Authors: Lin Jinsong , Wang Yanfeng , Pan Haidong , Wei Zexun , Xu Tengfei
Published: June 2023

Air–sea heat flux is one of the most important factors that affects ocean circulation, weather, and climate. Satellite remote sensing could serve as an important supplement to the sparse in situ observations for heat flux estimations. In this study, we analyze the uncertainty of the turbulent heat fluxes derived from wind speed measured by the Cyclone Global Navigation Satellite System (CYGNSS) over the global tropical oceans at different time scales. In terms of spatial distribution, there is large uncertainty (approximately 50 to 85 W·m−2 in the RMSE) near the equator in the western Pacific Ocean, the Arabian Sea, the Bay of Bengal, and near the Gulf of Guinea. The turbulent heat fluxes are in agreement with the buoys in representing the intraseasonal and seasonal variability, but more specific regional validations are needed for revealing the synoptic and sub-synoptic phenomena and the diurnal cycle. The uncertainty of the CYGNSS wind speed contributes approximately 50–57% to the uncertainty of the estimation of turbulent heat fluxes at the frequency band with a typical period of 3–7 days. In addition, the input sea surface temperature, rather than the wind speed, results in differences in the estimation of the monthly mean turbulent heat fluxes in the tropical Atlantic Ocean based on the COARE 3.5 algorithm. In conclusion, although the CYGNSS-derived turbulent heat fluxes are basically in good agreement with the in situ observations, our analysis highlights the importance of considering the limitations of these datasets, particularly in high wind speed conditions and for higher-frequency variations, including at synoptic, sub-synoptic, and diurnal time scales.
Forest Fire Monitoring Method Based on UAV Visual and Infrared Image Fusion
Authors: Liu Yuqi , Zheng Change , Liu Xiaodong , Tian Ye , Zhang Jianzhong , Cui Wenbin
Published: June 2023

Forest fires have become a significant global threat, with many negative impacts on human habitats and forest ecosystems. This study proposed a forest fire identification method by fusing visual and infrared images, addressing the high false alarm and missed alarm rates of forest fire monitoring using single spectral imagery. A dataset suitable for image fusion was created using UAV aerial photography. An improved image fusion network model, the FF-Net, incorporating an attention mechanism, was proposed. The YOLOv5 network was used for target detection, and the results showed that using fused images achieved a higher accuracy, with a false alarm rate of 0.49% and a missed alarm rate of 0.21%. As such, using fused images has greater significance for the early warning of forest fires.
Sexual Harassment and Assault across Trail and Ultrarunning Communities: A Mixed-Method Study Exploring Gender Differences
Authors: Teranishi Martinez Christy , Scott Tappan Crista , Baker Harley , Edwards Makayla , Martinez Juliane
Published: June 2023

This mixed-method study aimed to better understand the prevalence and qualitative experiences of sexual harassment and assault (SHSA) among trail and ultrarunners. Over 1500 runners (1215 females; 259 males; 28 transgender, non-binary, gender-fluid) of ages ranging from 18 to 77 (M = 39) responded to an online survey assessing the frequency and types of SHSA incidents experienced and the extent to which SHSA changed running behavior and feelings of safety. Respondents reported between 0 and over 100,000 incidents of SHSA, including catcalls, spanking, flashing, unwanted verbal advances, stalking, forced sexual acts, and rape. Of the 1502 respondents, 61% reported SHSA while running. Significantly higher rates of SHSA were reported by female, transgender, non-binary, and gender-fluid runners compared to male runners: 70% of female respondents and 61% of transgender, non-binary, and gender-fluid respondents reported incidents of SHSA compared to 17% of male respondents (all p < 0.001). Utilizing Mahalanobis procedures, discriminant, and chi-square analyses, a group of 75 responders was identified as outliers, reporting significantly more incidents of SHSA (1000 to 300,000) than the more normative respondents (p < 0.0001). For each type of SHSA, the two groups differed significantly in the number of reported incidents (p < 0.001). There were significant differences in perceived safety and how SHSA changed their running behavior. Gender inequities and challenging false memory claims are discussed. The findings underscore the importance of empowering runners to create a shared vision for the running community to promote safety and well-being.
Structural Relationship between Psychological Needs and Sport Adherence for Students Participating in Physical Education Class
Authors: García-Ceberino Juan M. , Feu Sebastián , Gamero María G. , Ibáñez Sergio J.
Published: June 2023

The satisfaction of basic psychological needs leads students to engage in a sport modality on their own initiative. In the Spanish public educational system, mixed and heterogeneous, the gender and sport experience of students influence the teaching and motivation of invasion sports. This study investigated whether students’ gender and sport experience, and model influence the psychological variables (basic psychological needs and sport adherence) when teaching school soccer and basketball. Furthermore, correlations were calculated between these psychological variables. The study involved 165 fifth and sixth grade students (Mage, 11.27 ± 0.68 years old) from several Spanish state schools in the same autonomous community. A non-random convenience sample was used. The needs for autonomy, perceived competence and social relationships were measured using the Basic Psychological Needs in Physical Exercise Scale. Sport adherence was measured using the Measure of Intentionality to be Physically Active. A Confirmatory Factor Analysis, Cronbach’s Alpha, Average Variance Extracted and Composite Reliability were used to analyze the psychometric properties of the scales. Descriptive and inferential analyses were obtained after performing a Mixed Linear Model and a Bonferroni Post Hoc. There were significant differences in the autonomy need according to the students’ gender (boys > girls). In addition, boys who learned with the TGA model scored significantly higher than girls on this need. Attending to sport adherence, there were significant differences in favor of experienced students. Likewise, a regression analysis (structural equation model) revealed that the autonomy need showed low association with sport adherence. Higher perceived competence (β = 0.52) and social relationships (β = 0.36) were associated with greater adherence to sport (R2 = 0.65). Teachers’ Knowledge and proper managing basic psychological needs will have educational, social and health benefits, as it will increase the likelihood of physical activity in and out of school.
Research on the Evaluation and Spatial–Temporal Evolution of Safe and Resilient Cities Based on Catastrophe Theory—A Case Study of Ten Regions in Western China
Authors: Xiang Yong , Chen Yonghua , Su Yangyang , Chen Zeyou , Meng Junna
Published: June 2023

In today’s highly complex world, urban security has become a focus of attention for people in various positions due to its enormous uncertainty. As an essential path towards urban safety, resilient development can effectively provide emergency management capability for cities when they are exposed to unknown risks. In this study, an evaluation-index system for urban-safety resilience was constructed from the perspective of sustainable urban development. The urban-safety-resilience evaluation model was established with the help of catastrophe theory to study and analyze urban-safety resilience. The corresponding spatial–temporal-evolution analysis used the geographic information system (GIS) and Moran index to evaluate the urban-security resilience of 10 regions in western China. Finally, it was concluded that (1) the urban-safety resilience of most regions in western China showed an increasing trend over time in 2017, 2019, and 2021; (2) the urban-safety resilience of Chongqing, Sichuan, and Shaanxi provinces is at a relatively high level compared to the western region overall; and (3) regions such as Ningxia and Gansu are disaster-prone, and urban infrastructure conditions are relatively backward. Therefore, urban planning and governance should be flexibly transformed to explore and apply appropriate urban-safety-resilience models, with sustainable development as the cornerstone.
HyFlex Learning Research and Practice: A Longitudinal Analysis
Authors: Wong Billy T. M. , Li Kam Cheong , Chan Hon Tung , Cheung Simon K. S.
Published: June 2023

This paper presents a longitudinal study analysing the literature on the hybrid and flexible mode of learning (HyFlex learning) in terms of its research and practice over the past decade. A total of 84 articles published between 2013 and 2022 were collected from Scopus for analysis, covering their changes in publication patterns, research issues, features of practices, benefits, and challenges, as well as the recommendations given in the articles along the years. The results show a sharp increase in publications since 2018. Relevant work was primarily carried out at the tertiary level of education, with an emphasis on issues in respect of teachers’ and students’ perceptions, experiences, and behaviours in HyFlex learning. Most of the practices were mediated by technologies, which were primarily used for course delivery, course management, and in-class/off-class communication. The recommendations made in the literature cover the roles of teachers and institutions as well as relevant support, which are noted to have an impact on the effective implementation of HyFlex learning. The findings contribute to providing an overview of the longitudinal development and current state of HyFlex learning as well as insights into its future development in both research and practice.