bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrochemistry of Flavonoids: A Comprehensive Review
Authors: Chiorcea-Paquim Ana-Maria
Published: October 2023

Flavonoids represent a large group of aromatic amino acids that are extensively disseminated in plants. More than six thousand different flavonoids have been isolated and identified. They are important components of the human diet, presenting a broad spectrum of health benefits, including antibacterial, antiviral, antimicrobial, antineoplastic, anti-mutagenic, anti-inflammatory, anti-allergic, immunomodulatory, vasodilatory and cardioprotective properties. They are now considered indispensable compounds in the healthcare, food, pharmaceutical, cosmetic and biotechnology industries. All flavonoids are electroactive, and a relationship between their electron-transfer properties and radical-scavenging activity has been highlighted. This review seeks to provide a comprehensive overview concerning the electron-transfer reactions in flavonoids, from the point of view of their in-vitro antioxidant mode of action. Flavonoid redox behavior is related to the oxidation of the phenolic hydroxy groups present in their structures. The fundamental principles concerning the redox behavior of flavonoids will be described, and the phenol moiety oxidation pathways and the effect of substituents and experimental conditions on flavonoid electrochemical behavior will be discussed. The final sections will focus on the electroanalysis of flavonoids in natural products and their identification in highly complex matrixes, such as fruits, vegetables, beverages, food supplements, pharmaceutical compounds and human body fluids, relevant for food quality control, nutrition, and healthcare research.
Genomic Exploration of Distinct Molecular Phenotypes Steering Temozolomide Resistance Development in Patient-Derived Glioblastoma Cells
Authors: Fabro Federica , Kers Trisha V. , Feller Kate J. , Beerens Cecile , Ntafoulis Ioannis , Idbaih Ahmed , Verreault Maite , Connor Kate , Biswas Archita , Salvucci Manuela , Prehn Jochen H. M. , Byrne Annette T. , O’Farrell Alice C. , Lambrechts Diether , Dilcan Gonca , Lodi Francesca , Arijs Ingrid , Kremer Andreas , Tching Chi Yen Romain , Chien Miao-Ping , Lamfers Martine L. M. , Leenstra Sieger
Published: October 2023

Chemotherapy using temozolomide is the standard treatment for patients with glioblastoma. Despite treatment, prognosis is still poor largely due to the emergence of temozolomide resistance. This resistance is closely linked to the widely recognized inter- and intra-tumoral heterogeneity in glioblastoma, although the underlying mechanisms are not yet fully understood. To induce temozolomide resistance, we subjected 21 patient-derived glioblastoma cell cultures to Temozolomide treatment for a period of up to 90 days. Prior to treatment, the cells’ molecular characteristics were analyzed using bulk RNA sequencing. Additionally, we performed single-cell RNA sequencing on four of the cell cultures to track the evolution of temozolomide resistance. The induced temozolomide resistance was associated with two distinct phenotypic behaviors, classified as “adaptive” (ADA) or “non-adaptive” (N-ADA) to temozolomide. The ADA phenotype displayed neurodevelopmental and metabolic gene signatures, whereas the N-ADA phenotype expressed genes related to cell cycle regulation, DNA repair, and protein synthesis. Single-cell RNA sequencing revealed that in ADA cell cultures, one or more subpopulations emerged as dominant in the resistant samples, whereas N-ADA cell cultures remained relatively stable. The adaptability and heterogeneity of glioblastoma cells play pivotal roles in temozolomide treatment and contribute to the tumor’s ability to survive. Depending on the tumor’s adaptability potential, subpopulations with acquired resistance mechanisms may arise.
Heart Rate Reduction and Outcomes in Heart Failure Outpatients
Authors: Memenga Felix , Rybczynski Meike , Magnussen Christina , Goßling Alina , Kondziella Christoph , Becher Nina , Becher Peter Moritz , Bernadyn Julia , Berisha Filip , Bremer Wiebke , Sinning Christoph , Blankenberg Stefan , Kirchhof Paulus , Knappe Dorit
Published: October 2023

Aim. Pharmacologic reduction in heart rate with beta-blockers (BB) or ivabradine is associated with improved survival in heart failure (HF) with sinus rhythm. We analyzed the association of different heart rate-reducing drug treatments on outcomes in HF outpatients. Methods. Consecutive patients with HF in sinus rhythm referred to a specialized tertiary service were prospectively enrolled from August 2015 until March 2018. Clinical characteristics were assessed at baseline. We performed Cox regression analyses to examine the effect of the resting heart rate and different heart rate-reducing drug regimens on all-cause mortality and a composite endpoint of “all-cause mortality or heart transplantation” over a mean follow-up of 3.1 years. Results. Of the 278 patients included, 213 (76.6%) were male, the median age was 57.0 years (IQR 49.0–66.1), and 185 (73.7%) had an ejection fraction <40%. Most patients received BB in submaximal [n = 118] or maximum dose [n = 136]. Patients on BB in maximum dose plus ivabradine [n = 24] were younger (53.0 vs. 58.0 years) and had a lower EF (25 vs. 31%). Higher resting heart rate was associated with an increased risk of death or transplantation (HR 1.03 [1.01, 1.06], p = 0.0072), even after adjusting for age and sex. There were no differences between the groups concerning all-cause mortality or the composite endpoint. Conclusion. Our prospective study confirms the association between low heart rate and survival in HF patients receiving various heart rate-reducing medications. We could not identify a specific effect of either regimen.
Accuracy of Palatal Orthodontic Mini-Implants Placed Using Fully Digital Planned Insertion Guides: A Cadaver Study
Authors: Stursa Lea , Wendl Brigitte , Jakse Norbert , Pichelmayer Margit , Weiland Frank , Antipova Veronica , Kirnbauer Barbara
Published: October 2023

Digital workflows have become integral in orthodontic diagnosis and therapy, reducing risk factors and chair time with one-visit protocols. This study assessed the transfer accuracy of fully digital planned insertion guides for orthodontic mini-implants (OMIs) compared with freehanded insertion. Cone-beam computed tomography (CBCT) datasets and intraoral surface scans of 32 cadaver maxillae were used to place 64 miniscrews in the anterior palate. Three groups were formed, two using printed insertion guides (A and B) and one with freehand insertion (C). Group A used commercially available customized surgical templates and Group B in-house planned and fabricated insertion guides. Postoperative CBCT datasets were superimposed with the planning model, and accuracy measurements were performed using orthodontic software. Statistical differences were found for transverse angular deviations (4.81° in A vs. 12.66° in B and 5.02° in C, p = 0.003) and sagittal angular deviations (2.26° in A vs. 2.20° in B and 5.34° in C, p = 0.007). However, accurate insertion depth was not achieved in either guide group; Group A insertion was too shallow (−0.17 mm), whereas Group B insertion was deeper (+0.65 mm) than planned. Outsourcing the planning and fabrication of computer-aided design and computer-aided manufacturing insertion guides may be beneficial for certain indications; particularly, in this study, commercial templates demonstrated superior accuracy than our in-house–fabricated insertion guides.
Anti-Amyloid Therapy, AD, and ARIA: Untangling the Role of CAA
Authors: Sin Mo-Kyung , Zamrini Edward , Ahmed Ali , Nho Kwangsik , Hajjar Ihab
Published: October 2023

Anti-amyloid therapies (AATs), such as anti-amyloid monoclonal antibodies, are emerging treatments for people with early Alzheimer’s disease (AD). AATs target amyloid β plaques in the brain. Amyloid-related imaging abnormalities (ARIA), abnormal signals seen on magnetic resonance imaging (MRI) of the brain in patients with AD, may occur spontaneously but occur more frequently as side effects of AATs. Cerebral amyloid angiopathy (CAA) is a major risk factor for ARIA. Amyloid β plays a key role in the pathogenesis of AD and of CAA. Amyloid β accumulation in the brain parenchyma as plaques is a pathological hallmark of AD, whereas amyloid β accumulation in cerebral vessels leads to CAA. A better understanding of the pathophysiology of ARIA is necessary for early detection of those at highest risk. This could lead to improved risk stratification and the ultimate reduction of symptomatic ARIA. Histopathological confirmation of CAA by brain biopsy or autopsy is the gold standard but is not clinically feasible. MRI is an available in vivo tool for detecting CAA. Cerebrospinal fluid amyloid β level testing and amyloid PET imaging are available but do not offer specificity for CAA vs amyloid plaques in AD. Thus, developing and testing biomarkers as reliable and sensitive screening tools for the presence and severity of CAA is a priority to minimize ARIA complications.
Reply to Farahani, P.; Wahid, L. Comment on “Viderman et al. Remote Monitoring of Chronic Critically Ill Patients after Hospital Discharge: A Systematic Review. J. Clin. Med. 2022, 11, 1010”
Authors: Viderman Dmitriy , Seri Elena , Aubakirova Mina , Abdildin Yerkin , Badenes Rafael , Bilotta Federico
Published: October 2023

Thank you very much for taking the time to read this systematic review and for sharing your thoughts [...]
Administering Antibiotics for Less Than Four Weeks Increases the Risk of Relapse in Culture-Positive Septic Arthritis of Native Joints
Authors: Joo Eun-Jeong , Kim Bomi , Sohn Kyung Mok , Kym Sungmin , Kim Jungok
Published: October 2023

(1) Objectives: This study investigated the optimal duration of antibiotic therapy and determined the risk factors associated with relapse in patients with culture-proven septic arthritis of native joints. (2) Methods: A retrospective review was conducted on patients aged ≥18 years diagnosed with native joint septic arthritis, with bacteria isolated from joints and/or blood. The exclusion criteria were prosthetic joint infections and cases with no identified microorganisms. The outcomes were assessed in the remission and relapse groups. (3) Results: Among 479 patients with native joint septic arthritis, 137 met the inclusion criteria, with a median follow-up duration of 2.7 years. The relapse rate was 9.5%, which mainly occurred within 30 days after antibiotic treatment completion. Compared with the remission group, the relapse group showed a significantly higher proportion of cases that received antibiotic therapy for ≤ 4 weeks (4.8% vs. 46.2%, p < 0.001), synovial fluid white blood cell (WBC) counts ≥150 × 103/mm3 (25.3% vs. 60.0%, p = 0.030), acute kidney injury (19.2% vs. 50%, p = 0.024), and extended-spectrum beta-lactamases-producing Enterobacteriaceae (0.8 vs. 15.4%, p = 0.024). Independent risk factors for relapse were determined as antibiotic therapy duration of ≤ 4 weeks (odds ratio (OR), 25.47; 95% confidence interval (CI), 1.57–412.33; p = 0.023) and synovial fluid WBC counts ≥150 × 103/mm3 (OR, 17.46; 95% CI, 1.74–175.62; p = 0.015). (4) Conclusions: Patients with native joint septic arthritis require vigilant monitoring for relapse, particularly when treated with antibiotic regimens administered for less than four weeks or when synovial aspirates exhibit elevated WBC counts at diagnosis.
Hydraulic Bottom Friction and Aerodynamic Roughness Coefficients for Mangroves in Southwest Florida, USA
Authors: Medeiros Stephen C.
Published: October 2023

Mangroves are a natural feature that enhance the resilience of natural and built coastal environments worldwide. They mitigate the impacts of hurricanes by dissipating energy from storm surges and waves, as well as reducing wind speeds. To incorporate mangroves into storm surge simulations, surface roughness parameters that accurately capture mangrove effects are required. These effects are typically parameterized using Manning’s n bottom friction coefficient for overland flow and aerodynamic roughness length (z0) for wind speed reduction. This paper presents the suggested values for these surface roughness parameters based on field observation and a novel voxel-based processing method for laser scanning point clouds. The recommended Manning’s n and z0 values for mangroves in southwest Florida are 0.138 and 2.34 m, respectively. The data were also used to retrain a previously developed random forest model to predict these surface roughness parameters based on point cloud statistics. The addition of the mangrove sites to the training data produced mixed results, improving the predictions of z0 while weakening the predictions of Manning’s n. The paper concludes that machine learning models developed to predict environmental attributes using small datasets with predictor features containing subjective estimates are sensitive to the uncertainty in the field observations.
A Novel Strategy for Emergency Treatment of Coronary Perforations by Placing a Drug-Eluting Stent before Sealing off the Leakage with a Covered Stent to Improve Long-Term Outcomes in Patients with Coronary Artery Perforations
Authors: Ayoub Mohamed , Corpataux Noé , Tajti Péter , Behnes Michael , Schupp Tobias , Forner Jan , Akin Ibrahim , Westermann Dirk , Rudolph Volker , Mashayekhi Kambis
Published: October 2023

We aimed to investigate the safety, feasibility, and long-term results of drug-eluting stent implantation before covered stents for treating coronary artery perforation (CAP). Between 2015 and 2020, 12,733 patients undergoing percutaneous coronary intervention (PCI) were retrospectively analyzed. The primary endpoint was 1-year target lesion revascularization (TLR), whereas secondary endpoints included the rate of major adverse cardiac and cerebrovascular events (MACCE) and all-cause death at 1 year. A total of 159 patients with CAP were identified during the study period, of whom 47.2% (n = 75) were treated with a covered stent (CS group) because of complex and/or severe CAP and 84 (52.8%) without (non-CS group). In the majority of patients, emergency drug-eluting stent placement before covered stent implantation was feasible (n = 69, 82%). There were no significant differences among patients treated with or without a covered stent in terms of primary or secondary clinical endpoints: a similar rate of TLR (18.67% vs. 21.43%, p = 0.6646), MACCE (25.33% vs. 22.62%, p = 0.6887), and 1-year mortality (12.00% vs. 11.90%, p = 0.9853) were identified comparing cases with covered stent implantation and without. In conclusion, our study implicates that the use of covered stents for sealing coronary perforation might not impact the 1-year clinical outcome if used properly. Moreover, the emergent use of drug-eluting stents before covered stent implantation in CAP is a safe and effective method to avoid target lesion revascularization in patients treated with covered stents.
Condylar Positional Changes in Skeletal Class II and Class III Malocclusions after Bimaxillary Orthognathic Surgery
Authors: Ravelo Víctor , Olate Gabriela , de Moraes Marcio , Huentequeo Claudio , Sacco Roberto , Olate Sergio
Published: October 2023

Orthognathic surgery is indicated to modify the position of the maxillomandibular structure; changes in the mandibular position after osteotomy can be related to changes in the position of the mandibular condyle in the articular fossa. The aim of this study was to determine changes produced in the mandibular condyle 6 months after orthognathic surgery. A cross-sectional study was conducted that included subjects who had undergone bimaxillary orthognathic surgery to treat dentofacial deformity of Angle class II (group CII) or Angle class III (group CIII). Standardized images were taken using cone-beam computed tomography 21 days before surgery and 6 months after surgery; measurement scales were used to identify the condylar position and its relations with the anterior, superior, and posterior joint spaces. The results were analyzed using the Shapiro–Wilk and Student’s t-tests, while considering a value of p < 0.05 as indicating a significant difference. Fifty-two joints from 26 patients, with an average age of 27.9 years (±10.81), were analyzed. All subjects in both group CII and group CIII showed a significant change in the anterior, superior, and posterior joint spaces. However, postoperative changes in the position of the condyle in the articular fossa were not significant in the anteroposterior analysis. We conclude that orthognathic surgery causes changes in the sagittal position of the mandibular condyle in subjects with mandibular retrognathism and prognathism.
What Is the Effect of Oil and Gas Markets (Spot/Futures) on Herding in BRICS? Recent Evidence (2007–2022)
Authors: Zhang Hang , Giouvris Evangelos
Published: October 2023

We investigate the effect of gas/oil markets (spot/futures) on herding in stock markets in BRICS over 15 years (2007–2022). We consider the effect(s) of crises (Global financial, European debt, COVID-19, and Russia–Ukraine war), bull/bearish energy markets, volatility, and speculation. The effect of gas and oil markets on herding in stock markets is minimal, and investors herd selectively during crises. Even during the ongoing Russia–Ukraine war, the effect of energy markets on herding in BRICS is minimal. Causality tests show that oil (spot/futures) Granger causes CSAD during COVID-19 only. Gas (spot/futures) has no effect. We also find that energy (spot/futures) market states (bearish/bullish) have no effect on herding in stock markets. Low volatility in energy markets can trigger herding (consistent with previous research in US, China) in all BRICS. Speculative activities during (non)crises appear to have minimal impact on herding. However, as the degree of intensity (volatility) in speculative activities increases in oil/gas, it causes herding in all countries (India is affected mostly), except Brazil. It is not the speculation activity per se in (non)crises that causes herding, but the intensity/volatility in speculation activity. Overall, oil/gas markets (especially gas markets) appear to have a smaller impact on herding than expected, contrary to public belief; however, as the intensity/volatility in speculative activities increases, then herding also increases, which is expected given the uncertainty that speculation causes.
A Fusion of Geothermal and InSAR Data with Machine Learning for Enhanced Deformation Forecasting at the Geysers
Authors: Yazbeck Joe , Rundle John B.
Published: October 2023

The Geysers geothermal field in California is experiencing land subsidence due to the seismic and geothermal activities taking place. This poses a risk not only to the underlying infrastructure but also to the groundwater level which would reduce the water availability for the local community. Because of this, it is crucial to monitor and assess the surface deformation occurring and adjust geothermal operations accordingly. In this study, we examine the correlation between the geothermal injection and production rates as well as the seismic activity in the area, and we show the high correlation between the injection rate and the number of earthquakes. This motivates the use of this data in a machine learning model that would predict future deformation maps. First, we build a model that uses interferometric synthetic aperture radar (InSAR) images that have been processed and turned into a deformation time series using LiCSBAS, an open-source InSAR time series package, and evaluate the performance against a linear baseline model. The model includes both convolutional neural network (CNN) layers as well as long short-term memory (LSTM) layers and is able to improve upon the baseline model based on a mean squared error metric. Then, after getting preprocessed, we incorporate the geothermal data by adding them as additional inputs to the model. This new model was able to outperform both the baseline and the previous version of the model that uses only InSAR data, motivating the use of machine learning models as well as geothermal data in assessing and predicting future deformation at The Geysers as part of hazard mitigation models which would then be used as fundamental tools for informed decision making when it comes to adjusting geothermal operations.
Integrated Terrestrial and Marine Ecosystem Services Valuation and Result Variation Trends: A Case Study of Jiangsu Province, China
Authors: Li Yan , Ren Bin , Li Feixue , Shi Xinjie , Jiang Penghui , Li Manchun
Published: October 2023

Quantitative ecosystem services valuation (ESV) is the key to effective environmental protection and ecosystem restoration. Studies have focused on terrestrial ecosystems and are mainly based on static analyses, excluding marine ecosystem service values and their variability. In this study, we comprehensively evaluated terrestrial and offshore ecosystem service values in Jiangsu Province in 2010 and 2018 using a table of unit area value equivalence factors and a vertically generalized production model (VGPM) to estimate marine primary productivity. The results showed that the terrestrial ESV in Jiangsu Province was 322.740 and 477.798 billion yuan in 2010 and 2018, respectively. The ESV of hydrological regulation in water areas was the highest, whereas that of unutilized land was the lowest. The ESV in different prefectural-level cities exhibited significant spatial heterogeneity and were highly correlated with the proportion, protection, and rational utilization of urban water areas. The offshore ESV in Jiangsu Province was 426.011 and 460.438 billion yuan in 2010 and 2018, respectively; the farther from land, the lower the ecosystem service value. The value of ecological regulation services is the dominant factor in the comprehensive services of terrestrial and offshore ecosystems in Jiangsu Province (accounting for 80% of ESV). From 2010 to 2018, the overall terrestrial and offshore ESV in Jiangsu Province rose by 188.901 billion yuan, increasing by 25.28% from 2010. In future, boundaries of development in production activities should be controlled, the protection and restoration of the ecological environment promoted, and regulatory functions and cultural services of ecosystems rationally exploited.
A Land Use Planning Literature Review: Literature Path, Planning Contexts, Optimization Methods, and Bibliometric Methods
Authors: Mehari Ashenafi , Genovese Paolo Vincenzo
Published: October 2023

Land use planning studies are accumulating in unprecedented quantities, and have created a wide space for an extensive summary, the synthesis of fundamental developments, a sharpening of the focus of future study issues, and the dissemination of concise information among the academic community and the policy making environment. Nonetheless, the publication rate and content coverage of land use planning literature reviews have been relatively low. This study aims to contribute to the field by first assessing the effectiveness of the bibliometric method as a literature study method. It then summarizes the developments in the land use planning literature in general path building process, the planning context, and the development of methods. The study findings highlight that the bibliometric method tends to reward information carriage papers rather than original contributors. More than 85% of the time, published articles are cited for general information rather than their core research contribution, suggesting the incomprehensiveness of the bibliometric method in studying real knowledge development. In terms of the land use planning context, significant gaps are observed, particularly in urban land use, including the detachment of the general goal-oriented objective formulations from basic land use allocation theories and conceptual models. A serious concern also arises that the formulations of certain urban land use optimization objectives appear to contradict the original concept of a sustainable city. To address these gaps, this paper suggests several key research frontiers, including linking the basic land use allocation and utility theories to land use optimization, and a need to shift current urban land use planning/optimization approaches from spatial optimization, which changes land uses to meet flow resources, towards optimizing the flow of resources to fit the resilient nature of existing spatial configurations and physical establishments in the built environment. Additionally, evaluating the existing built environment for optimality should be prioritized rather than solely focusing on new developments. In terms of method development, the study suggests that advancing current loosely coupled methods into more integrated systems may be a promising frontier. In general, the paper strongly suggests the possible reiteration of the land use planning study landscape to make sustainable development discourse more concrete and to make the method development stage involve more integrated systems. Immediate research interventions may be the standardizing of land use planning studies through the development of protocols and standard benchmark problems.
The Functions of Prosody in Action Formation in Australian Greek Talk-in-Interaction
Authors: Alvanoudi Angeliki
Published: October 2023

This study takes us to the Greek diasporic community in Cairns, Far North Queensland, Australia. The data analyzed derive from audio-recorded conversations with first-generation Greek immigrants collected during fieldwork in 2013. Drawing on interactional linguistics and contact linguistics, this paper analyzes the prosody of bilingual discourse markers and bilingual repetition in Australian Greek talk-in-interaction. It is shown that the prosodic features of code switches, namely pitch, intensity and duration, shape action formation and ascription. In the case of bilingual discourse markers, pitch serves as a contextualization cue that conveys the speaker’s stance and frames the different functions of the code-switched items. In bilingual repetition, speakers mobilize duration and intensity to prosodically differentiate the first iteration delivered in English from the second iteration delivered in Greek and, thus, frame the interpretation of the code switch as participant-related. This study sheds light on the pragmatic aspects of the phonetics of the Greek variety spoken in Cairns, and demonstrates that prosody shapes the functions of language contact-induced speech behavior in specific interactional contexts.
Prolactin in Polycystic Ovary Syndrome: Metabolic Effects and Therapeutic Prospects
Authors: Mastnak Lara , Herman Rok , Ferjan Simona , Janež Andrej , Jensterle Mojca
Published: October 2023

Polycystic ovary syndrome (PCOS) is the most prevalent endocrine and metabolic disorder in premenopausal women, characterized by hyperandrogenism, ovulatory dysfunction, and polycystic ovaries. Patients frequently present comorbidities, including obesity, insulin resistance, and impaired glucose and lipid metabolism. The diverse clinical presentation may mimic various endocrine disorders, making the diagnosis challenging in some clinical circumstances. Prolactin (PRL) is a recommended biomarker in the initial diagnostic workup to rule out hyperprolactinemia (HPRL). The traditional role of PRL is linked to lactation and the reproductive system. Recent research highlights PRL’s emerging role in metabolic homeostasis. PRL influences metabolism directly by interacting with the pancreas, liver, hypothalamus, and adipose tissue. Its influence on an individual’s metabolism is intricately tied to its serum concentration. While deficient and very high levels of PRL can negatively affect metabolism, intermediate–normal to moderately high levels may promote metabolic health. In women with PCOS, PRL levels may be altered. Research results on different aspects of the relationship between PCOS and the impact of various levels of PRL on metabolic homeostasis are limited and inconsistent. In this narrative literature review, we comprehensively examined data on serum PRL levels in PCOS patients. We investigated the correlation between a favorable metabolic profile and serum PRL levels in this population. Furthermore, we explored the concept of beneficial PRL effects on metabolism and discussed the potential therapeutic application of dopamine agonists in PCOS treatment. Lastly, we emphasized several promising avenues for future research in this field.
Analysis of Stress Concentration in Functionally Graded Plates with Linearly Increasing Young’s Modulus
Authors: Abdalla Hassan Mohamed Abdelalim , Casagrande Daniele , De Bona Francesco
Published: October 2023

In this article, the strain and stress analyses of functionally graded plates with circular holes that are subject to a uniaxial far-field traction load are analytically considered. The Young’s modulus is assumed to vary linearly along the radial direction around the hole. The adoption of such a type of inhomogeneity variation can be justified as follows. Firstly, and among all the possible variations of stiffness, the linear one is indeed the simplest inhomogeneity distribution. Surprisingly however, according to our knowledge extent, the associated elastic fields were not yet addressed in the literature. Secondly, a linearly varying stiffness could reasonably imply a remarkable advantage from a technological point of view. In fact, unlike nonlinearly varying stiffness plates, manufacturing routes are only required to handle constant variations throughout the radial domain. After recalling the basic equations for plane stress elasticity, the displacement, strain, and stress fields around the hole were numerically tackled and discussed for different stiffness ratios. A comparison was also carried out with other Young’s modulus distributions that have been commonly employed in the literature.
A Study on the Performance of Prestressed Concrete Containment with Carbon Fiber-Reinforced Polymer Tendons under Internal Pressure
Authors: Pan Xiaolan , Tian Aonan , Zhang Lianpeng , Zheng Zhi
Published: October 2023

As the last barrier to preventing nuclear leakage, it is crucial to enhance the load-bearing capacity and cracking resistance of nuclear containment under internal pressure accidents. Currently, fiber-reinforced polymers are widely used in prestressing concrete structures because of their superior performance, but little research has been conducted on fiber-reinforced polymers in the field of nuclear power plants. In this paper, carbon fiber-reinforced polymer (CFRP) is used as a prestressing tendon material instead of traditional steel strands to study the damage mode of the new type of containment under internal pressure and the feasibility of using CFRP as prestressing tendons. In this study, a three-dimensional refinement model is established, employing ABAQUS 2020 software to analyze and quantify the pressure-bearing performance of nuclear containment with CFRP tendons and finally determine the reasonable range of CFRP tendons that can be used as a replacement. The research shows that the containment with CFRP tendons has an obvious strengthening effect in delaying the generation of cracks, restraining the speed of crack development, reducing the plastic damage of the steel liner, and improving the ultimate bearing capacity of the containment.
Study on Dynamic Mechanics of Node-Enhanced Graded Lattice Structure and Application Optimization in Automobile Energy Absorbing Box
Authors: Wu Bin , Chen Qiulong , Liu Fuyuan , Chen Min , Lu Yi , Jiang Di , Yi Yang
Published: October 2023

Based on the lightweight characteristics of automotive energy absorption boxes and the requirement of good energy absorption effect, this article first applies the node-enhanced body centered cubic (NBCC) lattice structure to the inner core design of automotive energy absorption boxes. The gradient study of the NBCC lattice structure was carried out using a drop hammer impact and split Hopkinson pressure bar (SHPB). The results indicate that gradient lattice structures have advantages in energy absorption, but there are differences under different gradient strategies. When the impact is not sufficient to compact the structure, the vertical rod diameter gradient node-enhanced lattice structure (RGNBCC) can absorb more energy and improve energy absorption performance by 25%. The vertical height gradient node-enhanced lattice structure (HGNBCC) is more suitable for high-speed impact conditions. Based on the advantages of the RGNBCC in resisting low-speed impacts, it is applied to the inner core design of automotive energy absorption boxes and optimized using multi-objective optimization methods. The optimization results show that the maximum peak impact force is reduced by 45.6% and the specific energy absorption is increased by 30.4%.
Preparation and Performance of Ferric-Rich Bauxite-Tailing-Based Thermal Storage Ceramics
Authors: Wang Qi , Fang Minghao , Min Xin , Du Pengpeng , Huang Zhaohui , Liu Yangai , Wu Xiaowen , Liu Yulin , Liu Changmiao , Huang Feihui
Published: October 2023

In recent years, regenerative thermal oxidizer (RTO) has been widely used in the petroleum industry, chemical industry, etc. The massive storage required by solid waste has become a serious problem. Due to their chemical composition, bauxite tailings as raw materials for high-temperature thermal storage ceramics show enormous potential in the fields of research and application. In this study, we propose a method for preparing ferric-rich and high specific storage capacity by adding Fe2O3 powder to bauxite tailings. Based on a 7:3 mass ratio of bauxite tailings to lepidolite, Fe2O3 powder with different mass fractions (7 wt%, 15 wt%, 20 wt%, 30 wt%, and 40 wt%) was added to the ceramic material to improve the physical properties and thermal storage capacity of thermal storage ceramics. The results showed that ferric-rich thermal storage ceramics with optimal performance were obtained by holding them at a sintering temperature of 1000 °C for 2 h. When the Fe2O3 content was 15 wt%, the bulk density of the thermal storage ceramic reached 2.53 g/cm3, the compressive strength was 120.81 MPa, and the specific heat capacity was 1.06 J/(g·K). This study has practical guidance significance in the preparation of high thermal storage ceramics at low temperatures and low costs.
A Novel Tribometer and a Comprehensive Testing Method for Rolling-Sliding Conditions
Authors: Amoroso Pedro , Vrček Aleks , de Rooij Matthijn
Published: October 2023

This study introduces a method based on fine torque control to evaluate traction in rolling—liding line contacts under small slide-to-roll ratios (SRRs). To accomplish this, we engineered an innovative testing machine—a two-roller tribometer capable of precisely applying resisting torques to one of the rollers. Two types of tests were designed and conducted to validate our method and showcase the capabilities of the novel test setup. The first type, named the “Traction Decay Test”, proved to be effective in evaluating changes in the SRR over time. The second, named the “Torque-Mode Traction Test”, demonstrated its effectiveness in achieving ultra-low SRRs, in the order of 0.01%. As a result, traction curves with high resolution in the low SRR domain were constructed. This advancement provides the means for gaining a deeper understanding of traction coefficients, wear behavior, and tribological performance at ultra-low SRRs across diverse applications.
Exploring Complex Survival Data through Frailty Modeling and Regularization
Authors: Huang Xifen , Xu Jinfeng , Zhou Yunpeng
Published: October 2023

This study addresses the analysis of complex multivariate survival data, where each individual may experience multiple events and a wide range of relevant covariates are available. We propose an advanced modeling approach that extends the classical shared frailty framework to account for within-subject dependence. Our model incorporates a flexible frailty distribution, encompassing well-known distributions, such as gamma, log-normal, and inverse Gaussian. To ensure accurate estimation and effective model selection, we utilize innovative regularization techniques. The proposed methodology exhibits desirable theoretical properties and has been validated through comprehensive simulation studies. Additionally, we apply the approach to real-world data from the Medical Information Mart for Intensive Care (MIMIC-III) dataset, demonstrating its practical utility in analyzing complex survival data structures.
Best Approximation of Fixed-Point Results for Branciari Contraction of Integral Type on Generalized Modular Metric Space
Authors: Manav Tatar Nesrin , Agarwal Ravi P.
Published: October 2023

In the realm of generalized modular metric spaces, we substantiate the validity of fixed-point theorems with Branciari contractions. This paper expands and broadens the original theorems in this context. Subsequently, by building upon this foundation, we explore various integral contractions to identify and characterize fixed points within this context. To highlight the practical implications of our work, we introduce the concept of the best proximity pair, thereby culminating in the best approximation theorem. We apply this theoretical construct to a specific example—one that is guided by the best approximation method described in prior research.
Spectral, Scattering and Dynamics: Gelfand–Levitan–Marchenko–Krein Equations
Authors: Kabanikhin Sergey , Shishlenin Maxim , Novikov Nikita , Prokhoshin Nikita
Published: October 2023

In this paper, we consider the Gelfand–Levitan–Marchenko–Krein approach. It is used for solving a variety of inverse problems, like inverse scattering or inverse problems for wave-type equations in both spectral and dynamic formulations. The approach is based on a reduction of the problem to the set of integral equations. While it is used in a wide range of applications, one of the most famous parts of the approach is given via the inverse scattering method, which utilizes solving the inverse problem for integrating the nonlinear Schrodinger equation. In this work, we present a short historical review that reflects the development of the approach, provide the variations of the method for 1D and 2D problems and consider some aspects of numerical solutions of the corresponding integral equations.
A No-Chatter Single-Input Finite-Time PID Sliding Mode Control Technique for Stabilization of a Class of 4D Chaotic Fractional-Order Laser Systems
Authors: Roohi Majid , Mirzajani Saeed , Basse-O’Connor Andreas
Published: October 2023

Over the past decade, fractional-order laser chaotic systems have attracted a lot of attention from a variety of fields, including theoretical research as well as practical applications, which has resulted in the development of a number of different system classes. This paper introduces a novel single-input finite-time PID sliding mode control (SMC) technique to stabilize a specific group of unknown 4-dimensional chaotic fractional-order (FO) laser systems. By combining the PID concept with the FO-version of the Lyapunov stability theory, a novel finite-time PID SMC strategy has been developed, which effectively mitigates chaotic behavior in the mentioned unknown 4-dimensional chaotic FO laser system. This method makes use of a characteristic of FO chaotic systems known as boundedness, which is used here. Notably, the control input’s sign function, which is responsible for undesirable chattering, is transformed into the fractional derivative of the control input. This transformation results in a smooth and chattering-free control input, further enhancing the method’s performance. To demonstrate the efficacy of the proposed chattering-free–finite-time PID SMC technique, two numerical scenarios are presented, showcasing its efficient performance in stabilizing the unknown 4-dimensional chaotic FO laser system. These scenarios serve as illustrations of the method’s potential for practical applications.
Mechanical and Microstructural Characteristics of 1.5 GPa-Grade Boron Steel by High-Frequency Induction of Eddy Currents
Authors: Kim Kunyoung , Kang Myungchang
Published: October 2023

In the automobile industry, high-strength plates are increasingly used to reduce vehicle weight due to strict regulations on fuel efficiency and safety, and these plates achieve a tensile strength of 1500 MPa due to the hot-stamping process. Recently, research has been conducted to examine the flow behavior of materials according to the relationship between hot stamping time-temperature characteristics, coil shape, cooling method, and thermodynamic flow characteristics of quenching materials. In this study, a basic experiment in the form of a plate was conducted using an eddy current generated during high-frequency induction heating. It presents the surface temperature change, mechanical characteristics, and microstructure of boron steel that has undergone a high-frequency induction heating process. Surface temperature data were analyzed at different high-frequency induction heating forces (15, 18, 21, 24, 27, and 30 kW) and distances from specimens (6, 9, 12, and 15 mm). Two phases, austenite and ferrite, were formed in the low-temperature region, and martensite was formed in the high-temperature region. Mechanical properties and microstructures were also analyzed under different high-frequency induction heating coil conditions. The correlation between the high-frequency induction heating force and the specimen with the maximum tensile strength was investigated. Due to high-frequency induction heating, scale generation and surface decarbonization can be avoided. As a result of this experiment, 1500 MPa of the same tensile strength as the mechanical characteristics obtained in the existing heat treatment could be obtained.
Process Development of Screen-Printed Magnetic Sheets for Electric Machines via Statistical Design of Experiments
Authors: Schmidt Alexander , Wieprecht Nico , Schlichting Johannes , Denneler Stefan , Franke Jörg , Kuehl Alexander
Published: October 2023

Electrical machines play a major role in achieving a more sustainable economy by driving the further electrification of industry and transportation. To enhance the electric motor productivity during production and the efficiency during operation, it is essential to maximize the material yield rate during the production of stator and rotor sheet stacks and reduce iron losses during operation. Screen-printing technology can help to achieve these goals by producing thin magnetic sheet laminations in near-net-shape geometry, resulting in minimum material waste during production. Moreover, reducing the sheet thickness decreases the eddy current losses and avoids mechanical stress during manufacturing, leading to improved motor efficiency. Additionally, screen printing facilitates the production of multi-material components and variable alloy compositions. This study aims to identify the relevant factors and printing parameters so that screen-printed magnetic sheets can achieve product specifications. A method involving the statistical design of experiments is performed in several iterations to investigate the target parameters of the print cycle time, green part weight, shape integrity and layer thickness, and to analyze the main interdependencies. The results of this study provide valuable insights into optimizing the screen-printing process for soft magnetic sheets, enabling the production of efficient electric motors while reducing material scrap.
Electric-Force Conversion Performance of Si-Based LiNbO3 Devices Based on Four Cantilever Beams
Authors: Zhang Huiyi , Qiao Xiaojun , Wei Huifen , Li Xiaohuang , Wu Xiaohui , Yu Nanxin , Lu Hao , Guo Tao , Chou Xiujian , Geng Wenping
Published: October 2023

In micron or nano smart sensing systems, piezoelectric cantilever beams are distributed as major components in microsensors, actuators, and energy harvesters. This paper investigates the performance of four cantilever beam devices with “electric-force” conversion based on the inverse piezoelectric effect of lithium niobate (LiNbO3, LN) single-crystal materials. A new compact piezoelectric smart device model is proposed, designed as a single mass block connected by four beams, where devices exhibit smaller lateral errors (0.39–0.41%). The relationship between the displacement characteristics of cantilever beams and driving voltage was researched by applying excitation signals. The results show that the device has the maximum displacement at a first-order intrinsic frequency (fosc = 11.338 kHz), while the displacement shows a good linear relationship (R2 = 0.998) with driving voltage. The square wave signals of the same amplitude have greater “electrical-force” conversion efficiency. The output displacement can reach 12 nm, which is much higher than the output displacement with sinusoidal excitation. In addition, the relative displacement deviation of devices can be maintained within ±1% under multiple cycles of electrical signal loading. The small size, high reliability, and ultra-stability of Si–LN ferroelectric single-crystal cantilever beam devices with lower vibration amplitudes are promising for nanopositioning techniques in microscopy, diagnostics, and high-precision manufacturing applications.
Research on the Impact of Data Density on Memristor Crossbar Architectures in Neuromorphic Pattern Recognition
Authors: Le Minh , Truong Son Ngoc
Published: October 2023

Binary memristor crossbars have great potential for use in brain-inspired neuromorphic computing. The complementary crossbar array has been proposed to perform the Exclusive-NOR function for neuromorphic pattern recognition. The single crossbar obtained by shortening the Exclusive-NOR function has more advantages in terms of power consumption, area occupancy, and fault tolerance. In this paper, we present the impact of data density on the single memristor crossbar architecture for neuromorphic image recognition. The impact of data density on the single memristor architecture is mathematically derived from the reduced formula of the Exclusive-NOR function, and then verified via circuit simulation. The complementary and single crossbar architectures are tested by using ten 32 × 32 images with different data densities of 0.25, 0.5, and 0.75. The simulation results showed that the data density of images has a negative effect on the single memristor crossbar architecture while not affecting the complementary memristor crossbar architecture. The maximum output column current produced by the single memristor crossbar array decreases as data density decreases while the complementary memristor crossbar array architecture provides stable maximum output column currents. When recognizing images with data density as low as 0.25, the maximum output column currents of the single memristor crossbar architecture is reduced four-fold compared with the maximum currents from the complementary memristor crossbar architecture. This reduction causes the Winner-take-all circuit to work incorrectly and will reduce the recognition rate of the single memristor crossbar architecture. These simulation results show that the single memristor crossbar architecture has more advantages compared with the complementary crossbar architecture when the images do have not many different densities, and none of the images have very low densities. This work also indicates that the single crossbar architecture must be improved by adding a constant term to deal with images that have low data densities. These are valuable case studies for archiving the advantages of single memristor crossbar architecture in neuromorphic computing applications.