bluuebunny/crossref_metadata_2025 huggingface dataset:
Fixed-Time Adaptive Tracking Control for a Quadrotor Unmanned Aerial Vehicle with Input Saturation
Authors: Wang Haihui , Cui Guozeng , Li Huayi
Published: March 2023

Considering the problem of tracking control for a quadrotor unmanned aerial vehicle (QUAV) with input saturation, parameter uncertainties and external disturbances, a command filtered backstepping-based fixed-time adaptive control scheme was developed. The problem of “explosion of complexity” (EOC) is tackled by utilizing the fixed-time command filter, and the influence of filtered error is removed based on the fractional power-error-compensation mechanism. A fixed-time auxiliary system was designed to compensate for the input saturation of the QUAV. It strictly proves that the closed-loop system signals are fixed-time bounded, and the tracking errors converge to a sufficiently small region near the origin in a fixed time, and the convergence time is independent of the initial states. Finally, the effectiveness of the proposed fixed-time adaptive control algorithm is demonstrated via a numerical simulation.
Numerical Stabilization for Flutter Analysis Procedure
Authors: Yuan Weixing , Zhang Xiaoyang
Published: March 2023

Severe mode switching is often observed when the PK-method is used in the flutter analysis of complex aircraft configurations, in particular when nearly 100 vibrational modes are considered. In the commonly used commercial software NASTRAN, the resulting eigenroots are sorted in an ascending order of frequency. Therefore, the appearance of massive mode-switching instances cannot be avoided in the PK-method flutter analyses, especially for engineering applications with real-world complex configurations. In this study, as a post-processing procedure, an extensive sorting capability was developed in order to compensate for NASTRAN’s lack of a mode-tracking procedure in between the airspeed steps. The capability was developed based on both the complex eigenvalues and their corresponding eigenvectors. In addition, numerical techniques commonly used in computational fluid dynamics (CFD) were introduced to improve the convergence of the traditional PK-method. A hybrid approach was applied to the initial guess of the reduced frequency, followed by a deferred correction scheme for the PK-iteration process. Additionally, mode matching was specifically addressed when locking eigenroots onto the aerodynamics within the PK iterations. In addition to the PK iterations, a damping iteration or modified g-method was implemented by extending the PK-method solver. The combination of these special techniques effectively improved the numerical stability of the iterations in the stability eigensolution process and significantly reduced the appearance of the misleading mode switching, minimizing risks in aircraft flight.
Wheat Seed Phenotype Detection Device and Its Application
Authors: Zhang Haolei , Ji Jiangtao , Ma Hao , Guo Hao , Liu Nan , Cui Hongwei
Published: March 2023

To address the problem of low efficiency and automatically sense the phenotypic characteristics of wheat seeds, a wheat seed phenotype detection device was designed to predict thousand seed weight. Five commonly used varieties of wheat seeds were selected for the study, and a wheat seed phenotype detection system was built with a 2 mm sampling hole plate. Grayscale, image segmentation, area filtering and other methods were used to process the image in order to extract and analyse the correlation between thousand seed weight and seven phenotypic characteristics: wheat seed area, perimeter, long axis, short axis, ellipticity, rectangularity, and elongation. The results showed that different varieties of wheat seeds were significantly correlated with different phenotypic characteristics. Among them, the area and short axis for Luomai 26; the area, long axis, short axis, perimeter, and rectangularity for Jinqiang 11; the area and perimeter for Zhoumai 22; the area of Luomai 42; the area, short axis, and perimeter for Bainong 207 were significantly correlated with the thousand seed weight. A multiple linear regression model of thousand seed weight prediction was developed by selecting the significantly correlated phenotypic characteristic. The models showed that the R2 values of the thousand seed weight prediction models for Jinqiang 11 and Bainong 207 were 0.853 and 0.757, respectively; and the R2 values for Luomai 26, Zhoumai 22, and Luomai 42 were less than 0.5. Subsequently, PCA-MLR was used to build a thousand seed weight prediction model, and K-fold cross-validation was used for comparative analysis. Afterwards, three kinds of wheat seeds with 40–50 g thousand seed weight were selected to validate the model. The validation results showed that the more significantly correlated the phenotypic parameters were, the higher the accuracy of the thousand seed weight prediction model. The study provided a set of detection devices and methods for the rapid acquisition of the phenotypic characteristics of wheat seeds and thousand seed weight prediction.
Efficiency of Magnetically Treated Water on Decontamination of Chlorpyrifos® Residual: A Practically Water Insoluble Organophosphate in Brassica chinensis Linn.
Authors: Sudsiri Chadapust J. , Jumpa Natawat , Ritchie Raymond J.
Published: March 2023

Chlorpyrifos® (Thaion Agro Chemical CO., Ltd. Yannawa, Bangkok 10120, Thailand) (an almost water insoluble organophosphate insecticide) has been extensively used, resulting in the presence as a surface contaminant in foodstuffs, surface streams and soils. It is thus critically essential to develop methods to degrade or remove and eliminate this pollutant from environments. Chlorpyrifos® has very limited solubility and so it is primarily a contaminant of the surfaces of foodstuffs. We present the effect of magnetically treated water (MTW) to remove Chlorpyrifos® contaminating in Brassica chinensis Linn., a commonly eaten vegetable in Thailand and globally. Samples were washed with magnetically treated water (MTW) prior to detection of Chlorpyrifos® with GC-MS (Gas Chromatograph-Mass Spectroscopy). Chlorpyrifos® was removed by a factor of 413 times (−99.7%) by MTW compared to the un-washed sample, whereas the removal factor for tap water washing was only 9.6 (−89%). The MTW washed material easily passed safety criteria (Maximum Residue Load—MRL), but the tap water washed vegetables did not do so reliably. Although Chlorpyrifos® may be banned in many countries, the binding properties of replacement organophosphates are likely to be similar, and so our results should generalize to pesticides in the organophosphate chemical class that are not readily water soluble.
Subsurface Lateral Solute Transport in Turfgrass
Authors: Camacho Manuel E. , Faúndez-Urbina Carlos A. , Amoozegar Aziz , Gannon Travis W. , Heitman Joshua L. , Leon Ramon G.
Published: March 2023

Turfgrass managers have suspected that runoff-independent movement of herbicides and fertilizers is partially responsible for uneven turfgrass quality in sloped areas. We hypothesized that subsurface lateral solute transport might explain this phenomenon especially in areas with abrupt textural changes between surface and subsurface horizons. A study was conducted to track solute transport using bromide (Br−), a conservative tracer, as a proxy of turfgrass soil inputs. Field data confirmed the subsurface lateral movement of Br− following the soil slope direction, which advanced along the boundary between soil horizons over time. A model based on field data indicated that subsurface lateral movement is a mechanism that can transport fertilizers and herbicides away from the application area after they have been incorporated within the soil, and those solutes could accumulate and resurface downslope. Our results demonstrate that subsurface lateral transport of solutes, commonly ignored in risk assessment, can be an important process for off-target movement of fertilizers and pesticides within soils and turfgrass systems in sloped urban and recreational landscapes.
Research on Ditching Mechanism of Self-Excited Vibration Ditching Machine
Authors: Li Jun , Li Hongcai , Chen Yingyi , Lin Peiyi , Zhang Qianqian , Cheng Ying , Yang Zhou , Huang Guangwen
Published: March 2023

A vibration ditching machine is a machine that can effectively reduce ditching resistance and energy consumption. In this paper, taking a self-developed, self-excited vibration ditching machine as the research object, we explore its internal dynamic vibration characteristics upon excitement when ditching, which reduces its resistance and energy consumption. The vibration characteristics of a ditching machine with three degrees of freedom (Y, Ry, and Rx directions), which are generated by the vibration of the self-excited ditching machine, are evaluated; the rotating speed, spring stiffness, spring damping coefficient, and blade weight are taken as factors, and their effects on the vibration characteristics are analyzed by an Adams–Edem coupling simulation model and a theoretical dynamics model of the self-excited ditching machine. Finally, a comparative analysis of the ditching machine of self-excited and nonself-excited ditching machines is conducted. The results of the analysis show that the rotating speed, spring stiffness, spring damping coefficient, and blade weight are important factors affecting the vibration characteristics. The theoretical dynamics model and the Adams–Edem coupling simulation model can represent the internal vibration mechanism of the self-excited ditching machine during ditching. The self-excited vibrating ditching machine is helpful in reducing the energy consumption of ditching.
Use of Medical-Grade Honey to Treat Clinically Infected Heel Pressure Ulcers in High-Risk Patients: A Prospective Case Series
Authors: Papanikolaou Georgios E. , Gousios Georgios , Cremers Niels A. J.
Published: March 2023

Management of locally infected heel-pressure ulcers (HPUs) remains challenging, and given the increasing occurrence of infections resistant to antibiotic therapy and patients’ unwillingness to surgery, innovative and effective approaches must be considered. Medical-grade honey (MGH) could be an alternative therapeutic approach due to its broad-spectrum antimicrobial activity and healing properties. This study aimed to present the high effectiveness and safety of MGH for the conservative treatment of clinically infected HPUs. In this case series, we have prospectively studied nine patients with local signs of infected HPUs. In all cases, HPUs persisted for more than 4 weeks, and previous treatments with topical antibiotics or antiseptic products were ineffective. All patients were at high-risk to develop HPU infection due to their advanced age (median age of 86 years), several comorbidities, and permanent immobility. All wounds were treated with MGH products (L-Mesitran), leading to infection resolution within 3–4 weeks and complete wound healing without complication. Considering the failure of previous treatments and the chronic nature of the wounds, MGH was an effective treatment. MGH-based products are clinically and cost-effective for treating hard-to-heal pressure ulcers such as HPUs. Thus, MGH can be recommended as an alternative or complementary therapy in wound healing.
Assessment of the Microbiological Acceptability of White Cheese (Akkawi) in Lebanon and the Antimicrobial Resistance Profiles of Associated Escherichia coli
Authors: Hussein Nasri Daher , Hassan Jouman W. , Osman Marwan , El-Omari Khaled , Kharroubi Samer A. , Toufeili Imad , Kassem Issmat I.
Published: March 2023

Dairy foods are a staple in Lebanon, a low- and middle-income country that has been experiencing serious challenges to food safety and antimicrobial stewardship among other issues. The microbiological acceptability of dairy products has been of increasing concern. This is partially due to the failing economy and prolonged power outages that affect the quality of raw material and disrupt the dairy cold chain, respectively. Therefore, we assessed the microbiological acceptability of Akkawi, a popular white-brined cheese in Lebanon. For this purpose, we quantified the densities of Escherichia coli (a fecal indicator) and Staphylococcus aureus in cheeses collected from Lebanese retail stores. Additionally, we evaluated the antibiotic resistance profiles of the E. coli isolated from the cheese. E. coli and S. aureus were detected in 40 (80%) and 16 (32%) of the 50 cheese samples, respectively. Notably, 40 (80%) and 16 (32%) of the samples exceeded the maximum permissible limit of E. coli and S. aureus, respectively. A high percentage of the 118 E. coli isolated from the cheeses showed resistance to clinically and agriculturally important antibiotics, while 89 (75%) isolates were classified as multidrug-resistant (MDR). Given that Akkawi can be consumed without cooking, our findings highlight serious food safety and antimicrobial resistance problems that require immediate interventions.
Antimicrobial Resistant Pathogens Detected in Raw Pork and Poultry Meat in Retailing Outlets in Kenya
Authors: Muinde Patrick , Maina John , Momanyi Kelvin , Yamo Victor , Mwaniki John , Kiiru John
Published: March 2023

There is increasing proof of bacterial resistance to antibiotics all over the world, and this puts the effectiveness of antimicrobials that have been essential in decreasing disease mortality and morbidity at stake. The WHO has labeled some classes of antimicrobials as vitally important to human health. Bacteria from animals are thought to be reservoirs of resistance genes that can be transferred to humans through the food chain. This study aimed to identify the resistance patterns of bacteria from pork and poultry meat samples purchased from leading retail outlets in Kenya. Of the 393 samples collected, 98.4% of pork and 96.6% of poultry were contaminated with high levels of bacteria. Among the 611 bacterial isolates recovered, 38.5% were multi-drug resistant. This resistance was noted for critically essential antimicrobials (according to the WHO) such as rifampicin (96%), ampicillin (35%), cefotaxime (9%), cefepime (6%), and ciprofloxacin (6%). Moreover, there was high resistance to key antimicrobials for veterinary medicine such as tetracycline (39%), sulfamethoxazole (33%), and trimethoprim (30%). It is essential to spread awareness about the judicious use of antibiotics and take preventive measures to reduce disease burden.
Polyphosphate Ester-Type Transporters Improve Antimicrobial Properties of Oxytetracycline
Authors: Kozak Mariya , Stasiuk Anna , Vlizlo Vasyl , Ostapiv Dmytro , Bodnar Yulia , Kuz’mina Nataliia , Figurka Natalia , Nosova Natalia , Ostapiv Roman , Kotsumbas Igor , Varvarenko Sergiy , Samaryk Volodymyr
Published: March 2023

Prolonged use of antibiotics can cause toxicity in human and animal cells and lead to the development of antibiotic resistance. The development of drug delivery systems for enhanced antibacterial properties of antibiotics could reduce toxic effects and minimize the development of resistance. The aim of this study was to evaluate the effectiveness of oxytetracycline in complexes with new polyphosphate ester-type transporters and to investigate the antimicrobial effect of these complexes on Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus growth in vitro. Two polyphosphate ester-type transporters with different molecular weights were synthesized, and oxytetracycline was attached through the phosphorus groups. To determine the sensitivities of microorganisms, oxytetracycline hydrochloride and oxytetracycline complexes with polyphosphate ester-type transporters (P4 and P6) were added to liquid and solid media with E. coli, P. aeruginosa, and S. aureus in different doses. Oxytetracycline in complex with polyphosphate ester-type transporters at low doses (2.3 to 3.8 μg/disk or μg/mL) in both solid and liquid media inhibits the growth of S. aureus more effectively than oxytetracycline alone. The maximum influence on E. coli growth on solid media is observed at a dose of 8 μg/disk of oxytetracycline in combination with both P4 and P6 polyphosphate ester-type transporters. P. aeruginosa growth under the influence of oxytetracycline in combination with polyphosphate-ester type transporters in a liquid medium depends on the dose of antibiotic and the day of cultivation.
Molecular Characterization and Epidemiology of Antibiotic Resistance Genes of β-Lactamase Producing Bacterial Pathogens Causing Septicemia from Tertiary Care Hospitals
Authors: Khan Mohammad Riaz , Azam Sadiq , Ahmad Sajjad , Ali Qaisar , Liaqat Zainab , Rehman Noor , Khan Ibrar , Alharbi Metab , Alshammari Abdulrahman
Published: March 2023

Septicemia is a systematic inflammatory response and can be a consequence of abdominal, urinary tract and lung infections. Keeping in view the importance of Gram-negative bacteria as one of the leading causes of septicemia, the current study was designed with the aim to determine the antibiotic susceptibility pattern, the molecular basis for antibiotic resistance and the mutations in selected genes of bacterial isolates. In this study, clinical samples (n = 3389) were collected from potentially infected male (n = 1898) and female (n = 1491) patients. A total of 443 (13.07%) patients were found to be positive for bacterial growth, of whom 181 (40.8%) were Gram-positive and 262 (59.1%) were Gram-negative. The infected patients included 238 males, who made up 12.5% of the total number tested, and 205 females, who made up 13.7%. The identification of bacterial isolates revealed that 184 patients (41.5%) were infected with Escherichia coli and 78 (17.6%) with Pseudomonas aeruginosa. The clinical isolates were identified using Gram staining biochemical tests and were confirmed using polymerase chain reaction (PCR), with specific primers for E. coli (USP) and P. aeruginosa (oprL). Most of the isolates were resistant to aztreonam (ATM), cefotaxime (CTX), ampicillin (AMP) and trimethoprim/sulfamethoxazole (SXT), and were sensitive to tigecycline (TGC), meropenem (MEM) and imipenem (IPM), as revealed by high minimum inhibitory concentration (MIC) values. Among the antibiotic-resistant bacteria, 126 (28.4%) samples were positive for ESBL, 105 (23.7%) for AmpC β-lactamases and 45 (10.1%) for MBL. The sequencing and mutational analysis of antibiotic resistance genes revealed mutations in TEM, SHV and AAC genes. We conclude that antibiotic resistance is increasing; this requires the attention of health authorities and clinicians for proper management of the disease burden.
Antimicrobial Resistance Molecular Mechanisms of Helicobacter pylori in Jordanian Children: A Cross-Sectional Observational Study
Authors: Burayzat Salma , Al-Tamimi Mohammad , Barqawi Mohammad , Massadi Mustafa Sabri , Abu-Raideh Jumanah , Albalawi Hadeel , Khasawneh Ashraf I. , Himsawi Nisreen , Barber Maha
Published: March 2023

Background: H. pylori antimicrobial resistance causes increasing treatment failure rates among H. pylori gastritis in children. This study investigates the molecular mechanisms of H. pylori antimicrobial resistance among Jordanian children. Methods: Demographic, clinical, and laboratory data were recorded for children referred to Prince Hamzah Hospital. Clarithromycin, Metronidazole, and Levofloxacin susceptibility were tested via E-test. Clarithromycin-related mutations were investigated using Real-Time (RT)-PCR and Levofloxacin resistance was analyzed with DNA sequencing of the gyrA gene. Results: 116 children were recruited, including 55.2% females and 55.2% in the age range of 10.1 to 14 years. A total of 82.7% were naïve to eradication therapy. H. pylori positivity was 93.9%, 89.6%, 61.7%, and 84.3% according to Rapid Urease Test, histology, culture, and RT-PCR, respectively. Resistance rates were 25.9% for Clarithromycin, 50% for Metronidazole, and 6.9% for Levofloxacin via E-test. A2142G or A2143G or a combination of both mutations concerning Clarithromycin resistance were documented in 26.1% of samples, while mutations in gyrA gen-related to Levofloxacin resistance were reported in 5.3% of samples. Antibiotic resistance was significantly affected by abdominal pain, anemia, hematemesis, and histological findings (p < 0.05). Conclusion: H. pylori resistance was documented for Metronidazole and Clarithromycin. RT-PCR for H. pylori identification and microbial resistance determination are valuable alternatives for cultures in determining antimicrobial susceptibility.
Spatial and Temporal Protein Modules Signatures Associated with Alzheimer Disease in 3xTg-AD Mice Are Restored by Early Ubiquinol Supplementation
Authors: Llanos-González Emilio , Sancho-Bielsa Francisco J. , Frontiñán-Rubio Javier , Rabanal-Ruíz Yoana , García-Carpintero Sonia , Chicano Eduardo , Úbeda-Banon Isabel , Flores-Cuadrado Alicia , Giménez-Llort Lydia , Alcaín Francisco Javier , Peinado Juan Ramón , Durán-Prado Mario
Published: March 2023

Despite its robust proteopathic nature, the spatiotemporal signature of disrupted protein modules in sporadic Alzheimer’s disease (AD) brains remains poorly understood. This considered oxidative stress contributes to AD progression and early intervention with coenzyme Q10 or its reduced form, ubiquinol, delays the progression of the disease. Using MALDI–MSI and functional bioinformatic analysis, we have developed a protocol to express how deregulated protein modules arise from hippocampus and cortex in the AD mice model 3xTG-AD in an age-dependent manner. This strategy allowed us to identify which modules can be efficiently restored to a non-pathological condition by early intervention with ubiquinol. Indeed, an early deregulation of proteostasis-related protein modules, oxidative stress and metabolism has been observed in the hippocampus of 6-month mice (early AD) and the mirrored in cortical regions of 12-month mice (middle/late AD). This observation has been validated by IHC using mouse and human brain sections, suggesting that these protein modules are also affected in humans. The emergence of disrupted protein modules with AD signature can be prevented by early dietary intervention with ubiquinol in the 3xTG-AD mice model.
Effect of Astaxanthin on Tissue Transglutaminase and Cytoskeletal Protein Expression in Amyloid-Beta Stressed Olfactory Ensheathing Cells: Molecular and Delayed Luminescence Studies
Authors: Campisi Agatina , Sposito Giovanni , Grasso Rosaria , Bisicchia Julia , Spatuzza Michela , Raciti Giuseppina , Scordino Agata , Pellitteri Rosalia
Published: March 2023

Astaxanthin, a natural compound of Haematococcus pluvialis, possesses antioxidant, anti-inflammatory, anti-tumor and immunomodulatory activities. It also represents a potential therapeutic in Alzheimer’s disease (AD), that is related to oxidative stress and agglomeration of proteins such as amyloid-beta (Aβ). Aβ is a neurotoxic protein and a substrate of tissue transglutaminase (TG2), an ubiquitary protein involved in AD. Herein, the effect of astaxanthin pretreatment on olfactory ensheathing cells (OECs) exposed to Aβ(1–42) or by Aβ(25–35) or Aβ(35–25), and on TG2 expression were assessed. Vimentin, GFAP, nestin, cyclin D1 and caspase-3 were evaluated. ROS levels and the percentage of cell viability were also detected. In parallel, delayed luminescence (DL) was used to monitor mitochondrial status. ASTA reduced TG2, GFAP and vimentin overexpression, inhibiting cyclin D1 levels and apoptotic pathway activation which induced an increase in the nestin levels. In addition, significant changes in DL intensities were particularly observed in OECs exposed to Aβ toxic fragment (25–35), that completely disappear when OECs were pre-incubated in astaxantin. Therefore, we suggest that ASTA pre-treatment might represent an innovative mechanism to contrast TG2 overexpression in AD.
Beyond Antioxidant Activity: Redox Properties of Catechins May Affect Changes in the DNA Methylation Profile—The Example of SRXN1 Gene
Authors: Jakubek Patrycja , Rajić Jovana , Kuczyńska Monika , Suliborska Klaudia , Heldt Mateusz , Dziedziul Karol , Vidaković Melita , Namieśnik Jacek , Bartoszek Agnieszka
Published: March 2023

The role of catechins in the epigenetic regulation of gene expression has been widely studied; however, if and how this phenomenon relates to the redox properties of these polyphenols remains unknown. Our earlier study demonstrated that exposure of the human colon adenocarcinoma HT29 cell line to these antioxidants affects the expression of redox-related genes. In particular, treatment with (−)-epigallocatechin (EGC) downregulated transcription of gene encoding sulfiredoxin-1 (SRXN1), the peroxidase involved in the protection of cells against hydrogen peroxide-induced oxidative stress. The aim of this study was to investigate whether the observed SRXN1 downregulation was accompanied by changes in the DNA methylation level of its promoter and, if so, whether it was correlated with the redox properties of catechins. The impact on DNA methylation profile in HT29 cells treated with different concentrations of five catechins, varying in chemical structures and standard reduction potentials as well as susceptibility to oxidation, was monitored by a methylation-sensitive high-resolution melting technique employing the SRXN1 promoter region as a model target. We demonstrated that catechins, indeed, are able to modulate DNA methylation of the SRXN1 gene in a redox-related manner. The nonlinear method in the statistical analysis made it possible to fish out two parameters (charge transfer in oxidation process Qox and time of electron transfer t), whose strong interactions correlated with observed modulation of DNA methylation by catechins. Based on these findings, we present a proof-of-concept that DNA methylation, which limits SRXN1 expression and thus restricts the multidirectional antioxidant action of SRXN1, may represent a mechanism protecting cells against reductive stress caused by particularly fast-reacting reductants such as EGC and (−)-epicatechin gallate (ECG) in our study.
Inhibition of Pyruvate Dehydrogenase in the Heart as an Initiating Event in the Development of Diabetic Cardiomyopathy
Authors: Elnwasany Abdallah , Ewida Heba A. , Szweda Pamela A. , Szweda Luke I.
Published: March 2023

Obesity affects a growing fraction of the population and is a risk factor for type 2 diabetes and cardiovascular disease. Even in the absence of hypertension and coronary artery disease, type 2 diabetes can result in a heart disease termed diabetic cardiomyopathy. Diminished glucose oxidation, increased reliance on fatty acid oxidation for energy production, and oxidative stress are believed to play causal roles. However, the progression of metabolic changes and mechanisms by which these changes impact the heart have not been established. Cardiac pyruvate dehydrogenase (PDH), the central regulatory site for glucose oxidation, is rapidly inhibited in mice fed high dietary fat, a model of obesity and diabetes. Increased reliance on fatty acid oxidation for energy production, in turn, enhances mitochondrial pro-oxidant production. Inhibition of PDH may therefore initiate metabolic inflexibility and oxidative stress and precipitate diabetic cardiomyopathy. We discuss evidence from the literature that supports a role for PDH inhibition in loss in energy homeostasis and diastolic function in obese and diabetic humans and in rodent models. Finally, seemingly contradictory findings highlight the complexity of the disease and the need to delineate progressive changes in cardiac metabolism, the impact on myocardial structure and function, and the ability to intercede.
Safe-Shields: Basal and Anti-UV Protection of Human Keratinocytes by Redox-Active Cerium Oxide Nanoparticles Prevents UVB-Induced Mutagenesis
Authors: Corsi Francesca , Di Meo Erika , Lulli Daniela , Deidda Tarquini Greta , Capradossi Francesco , Bruni Emanuele , Pelliccia Andrea , Traversa Enrico , Dellambra Elena , Failla Cristina Maria , Ghibelli Lina
Published: March 2023

Cerium oxide nanoparticles (nanoceria), biocompatible multifunctional nanozymes exerting unique biomimetic activities, mimic superoxide-dismutase and catalase through a self-regenerating, energy-free redox cycle driven by Ce3+/4+ valence switch. Additional redox-independent UV-filter properties render nanoceria ideal multitask solar screens, shielding from UV exposure, simultaneously protecting tissues from UV-oxidative damage. Here, we report that nanoceria favour basal proliferation of primary normal keratinocytes, and protects them from UVB-induced DNA damage, mutagenesis, and apoptosis, minimizing cell loss and accelerating recovery with flawless cells. Similar cell-protective effects were found on irradiated noncancerous, but immortalized, p53-null HaCaT keratinocytes, with the notable exception that here, nanoceria do not accelerate basal HaCaT proliferation. Notably, nanoceria protect HaCaT from oxidative stress induced by irradiated titanium dioxide nanoparticles, a major active principle of commercial UV-shielding lotions, thus neutralizing their most critical side effects. The intriguing combination of nanoceria multiple beneficial properties opens the way for smart and safer containment measures of UV-induced skin damage and carcinogenesis.
The Economic and Environmental Evaluations of Combined Heat and Power Systems in Buildings with Different Contexts: A Systematic Review
Authors: Man Siu Shing , Lee Wilson Ka Ho , Chan Alan Hoi Shou , Tsang Steve Ngai Hung
Published: March 2023

Cogeneration systems—also known as combined heat and power systems—form a promising technology for the simultaneous generation of power and thermal energy while consuming a single source of fuel at a site. A number of prior studies have examined the cogeneration systems used in residential, commercial, and industrial buildings. However, a systematic review of the economic and environmental evaluations of the system is not found in the literature. The present study aims to address this research gap by reviewing the most relevant studies on the cogeneration systems applied to buildings in different contexts (e.g., residential, commercial, and industrial) and provides systematic evaluation approaches from economic and environmental perspectives. Results show that the cogeneration system can significantly reduce energy consumption, operating costs, carbon dioxide equivalent emissions, and positive performance on other relevant parameters. The present study provides extensive evidence to show that the cogeneration system is simultaneously economically profitable and environmentally friendly in various application contexts. To achieve the maximum benefits from cogeneration systems, several practical suggestions are provided for their successful installation and implementation in real-life situations.
An Evaluation of Landmark-Based Methods to Explore Tooth Score Morphology: A Case Study on Felids and Hyenids
Authors: Arriaza Mari Carmen , Aramendi Julia , Courtenay Lloyd A. , Maté-González Miguel Ángel , Herranz-Rodrigo Darío , González-Aguilera Diego , Yravedra José
Published: March 2023

Taphonomic studies aim to identify the modifying agents that intervene in bone assemblages found at archaeopaleontological sites. Carnivores may modify, accumulate, or scavenge skeletal parts inflicting tooth marks, including scores, on the cortical surface. Several works have studied tooth score morphology to discern which carnivore group modified the bone assemblages, achieving different results. In the present study, different methods based on the use of landmarks and semilandmarks have been tested to describe and analyze the score profile cross-sections of spotted and brown hyenas, leopards, and lions. According to our results, the already published seven-landmark method is useful in order to differentiate between carnivore species from different families (e.g., felids and hyenids). Meanwhile, felid species (e.g., leopards and lions) cannot be consistently distinguished using any of the methods tested here. In contrast, hyenid species can be morphologically differentiated. On the other hand, the use of semilandmarks does not generally improve morphological characterization and distinction, but low numbers of landmarks and the inclusion of the score’s deepest point might provide the best results when semi-automatic semilandmark models are preferred to avoid sampling biases.
Energy Minimization of New Robotic-Type Above-Knee Prosthesis for Higher Battery Lifetime
Authors: Ege Mucahit , Kucuk Serdar
Published: March 2023

In this paper, an optimization problem for the energy minimization of a new robotic-type three-axes above-knee prosthesis is carried out based on the actuator power consumption. The optimization problem aims to find the optimal link masses with which to minimize the electrical energy drawn from the battery of the new prosthesis, subject to the kinematic and dynamic constraints. Particle swarm optimization (PSO) is used as the optimization algorithm. A discrete-time PID controller is used to represent the saved energy by means of mass optimization. Optimization illustrated that energy consumption in the batteries can be reduced 51% and provides 1.89 h of additional battery lifetime, according to the literature, by optimizing prosthetic link masses while providing acceptable prosthesis stiffness.
Identifying At-Risk Students for Early Intervention—A Probabilistic Machine Learning Approach
Authors: Nimy Eli , Mosia Moeketsi , Chibaya Colin
Published: March 2023

The utilization of learning analytics to identify at-risk students for early intervention has exhibited promising results. However, most predictive models utilized to address this issue have been based on non-probabilistic machine learning models. In response, this study incorporated probabilistic machine learning for two reasons: (1) to facilitate the inclusion of domain knowledge, and (2) to enable the quantification of uncertainty in model parameters and predictions. The study developed a five-stage, probabilistic logistic regression model to identify at-risk students at different stages throughout the academic calendar. Rather than predicting a student’s final or exam mark, the model was focused on predicting the at-risk probabilities for subsequent assessments—specifically, the probability of a student failing an upcoming assessment. The model incorporated student engagement data from Moodle, as well as demographic and student performance data. The study’s findings indicate that the significance and certainty of student engagement and demographic variables decreased after incorporating student-performance variables, such as assignments and tests. The most effective week for identifying at-risk students was found to be week 6, when the accuracy was 92.81%. Furthermore, the average level of uncertainty exhibited by the models decreased by 60% from stage 3 to 5, indicating more reliable predictions at later than earlier stages. The study highlights the potential of a probabilistic machine learning model to aid instructors and practitioners in identifying at-risk students, and thereby to enhance academic outcomes.
Open-Set Specific Emitter Identification Based on Prototypical Networks and Extreme Value Theory
Authors: Wang Chunsheng , Wang Yongmin , Zhang Yue , Xu Hua , Zhang Zixuan
Published: March 2023

Much research has focused on classification within a closed set of emitters, while emitters outside this closed set are misclassified. This paper proposes an open-set recognition model based on prototypical networks and extreme value theory to solve the problem of specific emitter identification in open-set scenes and further improve the recognition accuracy and robustness. Firstly, a one-dimensional convolutional neural network was designed for recognizing I/Q signals, and a squeeze-and-excitation block with an attention mechanism was added to the network to increase the weights of the feature channels with high efficiency. Meanwhile, the recognition was improved by group convolution and channel shuffle. Then, the network was trained with the joint loss function based on prototype learning to complete the separation of intra-class signals and the aggregation of inter-class signals in the feature space. After the training, the Weibull model was fitted for pre-defined classes by incorporating the extreme value theory. Finally, the classification results were obtained according to the known classes and the Weibull model, effectively completing the open-set recognition. The simulation results showed that the proposed model had a higher recognition performance and robustness compared with other classical models for signals collected from five ZigBee and ten USRP 310 devices.
Dynamic Response of Outer Windshield Structure in Different Schemes under Aerodynamic Load
Authors: Tang Ming-Zan , Xiong Xiao-Hui , Li Xiao-Bai , Chen Guang , Zhang Jie , Zhong Mu , Sun Bo
Published: March 2023

With the increase in high-speed train (HST) operation speed, the light-weight design of the train body and component structure is pursued to reduce energy consumption during operation, but this seriously deteriorates the aerodynamic performance of the light-weight structure outside the train body under the effect of strong unsteady airflow, and the more obvious case is the frequently occurring problem of vibration, large deformation, and damage to the rubber exterior windshield at the connection position of HST carriages. We investigate the fluid–structure coupling mechanism of the interaction between the rubber external windshield and aerodynamic force, and compare the dynamic characteristics of windshield structure under different design parameters. A numerical simulation of three rubber outer windshield structure parameters (sidewall distance of U-shaped capsule, sidewall thickness, sidewall inclination angle) is carried out using FSI simulation of the two-way coupling method. The aerodynamic load, airflow dynamics around the windshield, and the nonlinear vibration and deformation form of the windshield is analyzed in detail. The results show that the aerodynamic response of the HST rubber external windshield analyzed by the FSI method is in good agreement with the full-scale test results. Additionally, the stiffness of the windshield can be improved by increasing the thickness of the windshield sidewall. When the distance between the sidewall of the windshield is increased, an insufficient thickness at the top of the arc causes a large local deformation at the top of the arc of the windshield. The method established and relevant research results can provide good support for the aerodynamic stability evaluation of HST windshields.
Effect of Asymmetric Feathering Angle on the Aerodynamic Performance of a Flyable Bionic Flapping-Wing Rotor
Authors: Chen Si , Wang Le , Guo Shijun , Tong Mingbo , He Yuanyuan , Hu Jie
Published: March 2023

The current study involves an experimental as well as numerical study on the aerodynamic behavior of a flapping-wing rotor (FWR) with different feathering amplitudes (−20°–50°, −50°–20°, and −35°–35°). In order to fulfil the experimental test, an FWR which weighs 18.7 g is designed in this manuscript. According to the experimental and numerical results, it was observed that, compared with the cases under a zero average stroke angle, the cases under a positive average stroke angle or negative average stroke angle share a higher rotary speed given the same input voltage. Despite the fact that the negative average stroke angle would facilitate the generation of a higher rotary speed, the negative average stroke angle cases tend to generate the smallest lift-to-power ratio. On the other hand, the cases with a positive average stroke angle tend to share the largest lift-to-power ratio (about 1.25 times those of zero average stroke angle cases and about 1.6 times those of negative average stroke angle cases). The above study indicates that the application of a positive average stroke angle can provide an effective solution to further increase the aerodynamic performance of a bio-inspired FWR.
Repulsive Force for Micro- and Nano-Non-Contact Manipulation
Authors: Cot Amélie , Rougeot Patrick , Lakard Sophie , Gauthier Michaël , Dejeu Jérôme
Published: March 2023

Non-contact positioning of micro-objects using electric fields has been widely explored, based on several physical principles such as electrophoresis, dielectrophoresis (DEP) or optical dielectrophoresis (ODEP), in which the actuation force is induced by an electric charge or an electric dipole placed in an electric field. In this paper, we introduce a new way to control charges in non-contact positioning of micro-objects using chemical functionalization (3-aminopropyl) triethoxysilane—APTES) able to localize charges on a substrate and/or on a micro-object. We demonstrate that this functionalization in a liquid with a low ionic strength is able to concentrate a significant amount of electric charges on surfaces generating an electric field over a long distance (about 10 microns), also called a large exclusion zone (EZ). A model is proposed and validated with electrostatic force measurements between substrate and microparticles (diameter up to 40 µm). We demonstrate that the magnitude of the force and the force range decrease rapidly when the ionic strength of the medium increases. Based on the proposed model, we show that this new way to localize charges on micro-objects may be used for non-contact positioning.
Mechanical Characteristics of an Open-Buried Double-Arch Tunnel during Construction
Authors: Lin Yu-Liang , Guo Ya-Lin , Yang Guo-Lin , Zhang Pei-Ran
Published: March 2023

The open excavation and concealed construction method is widely adopted for the construction of bias double-arch tunnels. However, the mechanical behavior of the tunnel during the whole construction period by using the open excavation and concealed construction method is not well understood, and the basis for construction organization and optimization is lacking. Based on an open-buried double-arch tunnel on Xiajuan Road, Changsha City, China, on-site monitoring was carried out in terms of the deformation of the steel arch in the primary lining, the stress of reinforcement in the secondary lining, and the deformation of the surrounding rock during the construction process. The correlation between the vault settlement rate and the steel arch strain was analyzed. The results show that the maximum vault settlement and settling rate of the left and right caverns occur at different locations due to different supporting conditions. The peripheral displacement experiences a process of convergence inward and extension outward. The compressive steel stress in the secondary lining of the right cavern is greater than that in the left cavern, except for the points at the arch waist. The backfill above the left cavern reduces the loading on the lining of the right cavern, but it increases the loading on the left cavern. The bias effect of the open-buried double-arch tunnel is well controlled and balanced when the open excavation and concealed construction method is adopted.
Measurement of Visible Radiation through a Sansevieria cylindrica-Based “Living Sensor”
Authors: Trigona Carlo , Puglisi Ivana , Baglieri Andrea , Gueli Anna M.
Published: March 2023

This research activity regards the development of a sensor based on a Sansevieria cylindrica plant for the measurement of visible radiation. The proposed solution, based on the adoption of a soil-plant system as a chemo-electrical transducer, goes beyond “classical” silicon-based approaches that are not biodegradable nor eco-friendly and that produce CO2 from the production step to the disposal phase. It is worth noting that no toxicity can be associated with plants and, due to the natural process of photosynthesis, these systems, used as living sensors, are even able to absorb carbon dioxide from the environment. The working principle of the proposed device based on the metabolic processes of the natural organisms present in the living system, soil and plant, as a function of visible radiation will be presented here. Particular emphasis will be also given to the analysis of the visible radiation spectrum, the metrological characterization, the performance of the device, and the analyses in terms of insensitivity to other external physical quantities. The obtained results evince the suitability of the proposed device which presents the prerogative of being environmentally friendly, self-generating, battery-less, simple, mimetic, low-cost, non-toxic, and biodegradable. The aforementioned features pave the road for a disruptive technological approach for an ecological transition which can impact the variegated applied field, including in the security, cultural heritage, smart home, and smart agriculture aspects.
The Comprehensive Reduction Capacity of Five Riparian Vegetation Buffer Strips for Primary Pollutants in Surface Runoff
Authors: Hu Yanxin , Gao Lin , Ma Chuanming , Wang Hao , Zhou Chi
Published: March 2023

Most studies on the effects of plants on reducing pollutants in surface runoff focus on the elimination of a single pollutant by a single plant species. We take into account the fact that natural riparian herbaceous vegetation buffer strips remove multiple pollutants at the same time, and vegetation species need to be selected according to actual conditions. In an indoor simulation, processed soil samples were taken, and collected rainwater was used to prepare standard solutions for simulating surface runoff, which includes five primary water pollutants: total suspended solids (TSS), total nitrogen (TN), total phosphorus (TP), ammonia nitrogen (NH3-N), and chemical oxygen demand (COD). Pollutant concentrations were measured after the experiments. We found that the reduction capacity of vegetation buffer strips differs due to the differentiation of biological structure and growth characteristics. Dichondra repens Forst and Cynodon dactylon (Linn.) Pers had high biomass, and their vegetation was creeping on the ground with well-developed roots, showing a strong comprehensive ability to reduce pollutants. The comprehensive reduction capability of five vegetation buffer strips for pollutants is ranked as follows: Dichondra repens Forst > Cynodon dactylon (Linn.) Pers > Zoysia matrella > Festuca elata Keng ex E. Alexeev > Lolium perenne.
Outlier Detection in Time-Series Receive Signal Strength Observation Using Z-Score Method with Sn Scale Estimator for Indoor Localization
Authors: Yaro Abdulmalik Shehu , Maly Filip , Prazak Pavel
Published: March 2023

Collecting time-series receive signal strength (RSS) observations and averaging them is a common method for dealing with RSS fluctuation. However, outliers in the time-series observations affect the averaging process, making this method less efficient. The Z-score method based on the median absolute deviation (MAD) scale estimator has been used to detect outliers, but it is only efficient with symmetrically distributed observations. Experimental analysis has shown that time-series RSS observations can have a symmetric or asymmetric distribution depending on the nature of the environment in which the measurement was taken. Hence, the use of the Z-score method with the MAD scale estimator will not be efficient. In this paper, the Sn scale estimator is proposed as an alternative to MAD to be used with the Z-score method in detecting outliers in time-series RSS observations. Performance comparison using an online RSS dataset shows that the Z-score with MAD and Sn as scale estimators falsely detected about 50% and 13%, respectively, of the RSS observations as outliers. Furthermore, the average absolute RSS median deviations between raw and outlier-free observations are 3 dB and 0.25 dB, respectively, for the MAD and Sn scale estimators, corresponding to a range error of about 2 m and 0.5 m.