bluuebunny/crossref_metadata_2025 huggingface dataset:
Knowledge attainment, learning approaches, and self-perceived study burnout among European veterinary students
Authors: Iivanainen Antti , Collares Carlos Fernando , Wandall Jakob , Parpala Anna , Nevgi Anne , Keto-Timonen Riikka , Tipold Andrea , Schaper Elisabeth , van Haeften Theo , Pihl Tina Holberg , Press Charles McLean , Holm Peter
Published: July 2024

Introduction

This study investigates the relationship between approaches to learning, self-perceived study burnout, and the level of knowledge among veterinary students. Veterinary educational programs are under regular development and would benefit greatly from detailed feedback on students' knowledge, proficiency, influencing factors, and coping mechanisms.

Methods

The VetRepos consortium developed and calibrated an item repository testing knowledge across the entire veterinary curriculum. Two hundred forty-eight students from seven European veterinary institutions took the VetRepos test, comprising a subset of the repository. They also responded to a questionnaire assessing deep and unreflective learning approaches and self-perceived study burnout, represented by exhaustion and cynicism. Structural equation modeling analyzed the relationship between these latent traits and the VetRepos test score.

Results

The model failed the exact-fit test but was retained based on global fit indices, inter-item residual correlations, and standardized residual covariances. Root Mean Square Error of Approximation with robust standard errors and scaled test statistic was 0.049 (95% confidence interval 0.033–0.071), scaled and robust Comparative Fit Index 0.95 (0.90–0.98), and scaled Standardized Root Mean Square Residual 0.056 (0.049–0.071). Measurement invariance across study years was not violated (ΔCFI = 0.00, χ2 = 3.78, Δdf = 4, p = 0.44), but it could not be confirmed between genders or universities. The VetRepos test score regressed on the study year [standardized regression coefficient = 0.68 (0.62–0.73)], showed a negative regression on the unreflective learning approach [−0.25 (−0.47 to −0.03)], and a positive regression on the deep approach [0.16 (0.03–0.28)]. No direct association with perceived burnout was observed; however, a significant, medium-sized association was found between the unreflective approach and self-perceived study burnout. No significant differences in learning approaches or perceived burnout were found between study years.

Discussion

The most important source of variance in VetRepos test scores, unrelated to the study year, was the learning approach. The association between the VetRepos test score and self-perceived burnout was indirect. Future research should complement this cross-sectional approach with longitudinal and person-oriented studies, further investigating the relationship between study burnout and learning approaches.
Neurological manifestations in dogs with acute leukemia
Authors: Lyseight Filipa L. S. , Pittaway Charles , Dennis Ruth , Cherubini Giunio B.
Published: July 2024

Canine acute leukemia is a rare hematopoietic neoplasm. Neurological abnormalities have been frequently reported in dogs with acute leukemia (AL). However, the description of the presentation and findings are limited. This study aimed to describe the clinical findings in dogs with acute leukemia presenting with neurological signs as their primary complaint. The database of a private referral hospital was searched for cases that presented to the neurological department with neurological deficits and were subsequently diagnosed with acute leukemia. Six cases were included; all had neurological clinical signs and an abnormal neurological examination. All cases had a focal neuroanatomical localisation on neurological examination (brain n = 4; spinal = 2). Out of the four dogs with a complete magnetic resonance imaging (MRI) study, there was an ill-defined infiltrative pattern with abnormal signal intensity in the central nervous system (CNS) in three dogs and the loss of grey and white matter differentiation in the brain (n = 2) and/or spinal cord (n = 2). Other MRI findings included abnormal meningeal enhancement (n = 3), changes affecting spinal nerves and epaxial muscles (n = 2), and lymphadenopathy in the field of view (n = 2). The bone marrow assessment on MRI showed evidence of signal change (n = 3), characterized by a loss of normal fat opacity and an abnormal degree of contrast enhancement. The cerebrospinal fluid (CSF) analysis of the four dogs showed an increased protein level with non-specific pleocytosis and without evidence of malignant cells. Treatment with cytotoxic medication was implemented in two dogs. The dogs diagnosed with acute leukemia had focal neuroanatomical localisation, an infiltrative CNS pattern, and bone marrow remodulation on MRI with an increase in CSF protein and negative cytology analysis.
Theileria orientalis Ikeda infection does not negatively impact growth performance or breeding soundness exam results in young beef bulls at bull test stations
Authors: Guynn Sierra R. , Greiner Scott P. , Currin John F. , Todd S. Michelle , Assenga Alphonce , Hungerford Laura L. , Lahmers Kevin K.
Published: July 2024

Introduction

Theileria orientalis Ikeda genotype is an emerging cattle disease in the US. Since 2017, when T. orientalis Ikeda was discovered in beef cattle in two counties in Virginia, cattle infections have risen to include ~67% of Virginia counties and 14 states. Consistent with New Zealand studies, many infected herds in Virginia were >90% positive upon initial testing without overt evidence of infection. Central bull tests present a unique opportunity to study the effects of T. orientalis Ikeda infections, as bulls from multiple source herds are consolidated. The objective of this study was to determine if infection with T. orientalis Ikeda affected the average daily gain (ADG), adjusted yearling weight (AYW) and breeding soundness of bulls at two test stations in Virginia over a period of years.

Materials and methods

The bulls were fed and housed similarly to compare their growth performance and breeding soundness. For T. orientalis Ikeda testing, DNA was extracted from whole blood for quantitative polymerase chain reaction.

Results

The number of bulls infected with T. orientalis Ikeda at initial delivery to the stations increased significantly over the years studied. Multivariable linear regression models, using Angus bulls from Virginia test stations, indicated no significant effect on ADG or AYW in bulls that became test positive during the test or were positive for the duration, compared to Angus bulls that were negative for the duration. At LOC A, the odds of passing a breeding soundness exam (BSE) were not significantly different for bulls that turned positive during the test or were positive for the duration, compared to bulls that were negative for the duration of the test. At LOC B, bulls that became positive during the test were 2.4 times more likely (95% CI: 1.165–4.995, p = 0.016) to pass their BSE compared to bulls that remained negative throughout the test.

Discussion

We do not suppose that an obscured infection of T. orientalis Ikeda is protective for bulls to pass a BSE. However, this study demonstrates an obscured infection of T. orientalis Ikeda does not negatively affect weight gain or achievement of a satisfactory BSE rating at the central bull test stations in Virginia.
Changes in Time to Initial Physician Contact and Cancer Stage Distribution during the COVID-19 Pandemic in Patients with Head and Neck Squamous Cell Carcinoma at a Large Hungarian Cancer Center
Authors: Szabó Éva , Kopjár Eszter , Rumi László , Boronkai Árpád , Bellyei Szabolcs , Gyöngyi Zoltán , Zemplényi Antal , Sütő Balázs , Girán János , Kiss István , Pozsgai Éva , Szanyi István
Published: July 2024

The aim of our study was to compare the characteristics and time to initial physician contact in patients with head and neck squamous cell carcinoma (HNSCC) before and during the COVID-19 pandemic at a large Hungarian cancer center. This was a retrospective study of patients 18 years or older presenting at the regional cancer center of Pécs Clinical Center with HNSCC between 1 January 2017, and 15 March 2020 (the pre-COVID-19 period) and between 16 March 2020, and 13 May 2021 (the COVID-19 period). Demographic and clinical data were collected, and the time between initial symptom onset and initial physician contact (TTP) was determined. Descriptive and exploratory statistical analyses were performed. On average, the number of patients diagnosed with HNSCC per month during the pandemic decreased by 12.4% compared with the pre-COVID-19 period. There was a significant increase in stage I and stage II cancers (from 15.9% to 20.3% and from 12.2% to 13.8%, respectively; p < 0.001); a decrease in stage III and IVa,c cancers; and a significant increase in stage IVb cancers (from 6% to 19.9%; p < 0.001) during the pandemic. The median TTP increased during the pandemic from 43 to 61 days (p = 0.032). To our knowledge, this is the first study investigating the effect of COVID-19 on patients with HNSCC in the Central–Eastern European region. We found a bidirectional shift in cancer stages and increased TTP during the pandemic. Our findings highlight the necessity for more nuanced analyses of the effects of COVID-19.
Intrusion Detection in IoT Using Deep Residual Networks with Attention Mechanisms
Authors: Cui Bo , Chai Yachao , Yang Zhen , Li Keqin
Published: July 2024

Connected devices in IoT systems usually have low computing and storage capacity and lack uniform standards and protocols, making them easy targets for cyberattacks. Implementing security measures like cryptographic authentication, access control, and firewalls for IoT devices is insufficient to fully address the inherent vulnerabilities and potential cyberattacks within the IoT environment. To improve the defensive capabilities of IoT systems, some research has focused on using deep learning techniques to provide new solutions for intrusion detection systems. However, some existing deep learning-based intrusion detection methods suffer from inadequate feature extraction and insufficient model generalization capability. To address the shortcomings of existing detection methods, we propose an intrusion detection model based on temporal convolutional residual modules. An attention mechanism is introduced to assess feature scores and enhance the model’s ability to concentrate on critical features, thereby boosting its detection performance. We conducted extensive experiments on the ToN_IoT dataset and the UNSW-NB15 dataset, and the proposed model achieves accuracies of 99.55% and 89.23% on the ToN_IoT and UNSW-NB15 datasets, respectively, with improvements of 0.14% and 15.3% compared with the current state-of-the-art models. These results demonstrate the superior detection performance of the proposed model.
Quantitative Trait Loci Mapping and Comparative Transcriptome Analysis of Fruit Weight (FW) in Watermelon (Citrullus lanatus L.)
Authors: Guo Song , Tian Mei , Du Huiying , Liu Shengfeng , Yu Rong , Shen Huolin
Published: July 2024

The watermelon (Citrullus lanatus L.) holds substantial economic value as a globally cultivated horticultural crop. However, the genetic architecture of watermelon fruit weight (FW) remains poorly understood. In this study, we used sh14-11 with small fruit and N14 with big fruit to construct 100 recombinant inbred lines (RILs). Based on whole-genome resequencing (WGR), 218,127 single nucleotide polymorphisms (SNPs) were detected to construct a high-quality genetic map. After quantitative trait loci (QTL) mapping, a candidate interval of 31–38 Mb on chromosome 2 was identified for FW. Simultaneously, the bulked segregant analysis (BSA) in the F2 population corroborated the identification of the same interval, encompassing the homologous gene linked to the known FW-related gene fas. Additionally, RNA-seq was carried out across 11 tissues from sh14-11 and N14, revealing expression profiles that identified 1695 new genes and corrected the annotation of 2941 genes. Subsequent differential expression analysis unveiled 8969 differentially expressed genes (DEGs), with 354 of these genes exhibiting significant differences across four key developmental stages. The integration of QTL mapping and differential expression analysis facilitated the identification of 14 FW-related genes, including annotated TGA and NAC transcription factors implicated in fruit development. This combined approach offers valuable insights into the genetic basis of FW, providing crucial resources for enhancing watermelon cultivation.
Differential Gene Expression in Contrasting Common Bean Cultivars for Drought Tolerance during an Extended Dry Period
Authors: Ponce Talita Pijus , Bugança Michely da Silva , da Silva Victória Stern , de Souza Rogério Fernandes , Moda-Cirino Vânia , Tomaz Juarez Pires
Published: July 2024

Common beans (Phaseolus vulgaris L.), besides being an important source of nutrients such as iron, magnesium, and protein, are crucial for food security, especially in developing countries. Common bean cultivation areas commonly face production challenges due to drought occurrences, mainly during the reproductive period. Dry spells last approximately 20 days, enough time to compromise production. Hence, it is crucial to understand the genetic and molecular mechanisms that confer drought tolerance to improve common bean cultivars’ adaptation to drought. Sixty six RNASeq libraries, generated from tolerant and sensitive cultivars in drought time sourced from the R5 phenological stage at 0 to 20 days of water deficit were sequenced, generated over 1.5 billion reads, that aligned to 62,524 transcripts originating from a reference transcriptome, as well as 6673 transcripts obtained via de novo assembly. Differentially expressed transcripts were functionally annotated, revealing a variety of genes associated with molecular functions such as oxidoreductase and transferase activity, as well as biological processes related to stress response and signaling. The presence of regulatory genes involved in signaling cascades and transcriptional control was also highlighted, for example, LEA proteins and dehydrins associated with dehydration protection, and transcription factors such as WRKY, MYB, and NAC, which modulate plant response to water deficit. Additionally, genes related to membrane and protein protection, as well as water and ion uptake and transport, were identified, including aquaporins, RING-type E3 ubiquitin transferases, antioxidant enzymes such as GSTs and CYPs, and thioredoxins. This study highlights the complexity of plant response to water scarcity, focusing on the functional diversity of the genes involved and their participation in the biological processes essential for plant adaptation to water stress. The identification of regulatory and cell protection genes offers promising prospects for genetic improvement aiming at the production of common bean varieties more resistant to drought. These findings have the potential to drive sustainable agriculture, providing valuable insights to ensure food security in a context of climate change.
Validation of Gene Expression Patterns for Oral Feeding Readiness: Transcriptional Analysis of Set of Genes in Neonatal Salivary Samples
Authors: Gomes Leonardo Henrique Ferreira , Marques Andressa Brito , Dias Isabel Cristina de Meireles , Gabeira Sanny Cerqueira de O. , Barcelos Tamara Rosa , Guimarães Mariana de Oliveira , Ferreira Igor Ribeiro , Guida Letícia Cunha , Lucena Sabrina Lopes , Rocha Adriana Duarte
Published: July 2024

Background: Neonatal health assessment is crucial for detecting and intervening in various disorders. Traditional gene expression analysis methods often require invasive procedures during sample collection, which may not be feasible or ideal for preterm infants. In recent years, saliva has emerged as a promising noninvasive biofluid for assessing gene expression. Another trend that has been growing is the use of “omics” technologies such as transcriptomics in the analysis of gene expression. The costs for carrying out these analyses and the difficulty of analysis make the detection of candidate genes necessary. These genes act as biomarkers for the maturation stages of the oral feeding issue. Methodology: Salivary samples (n = 225) were prospectively collected from 45 preterm (<34 gestational age) infants from five predefined feeding stages and submitted to RT-qPCR. A better description of the targeted genes and results from RT-qPCR analyses were included. The six genes previously identified as predictive of feeding success were tested. The genes are AMPK, FOXP2, WNT3, NPHP4, NPY2R, and PLXNA1, along with two reference genes: GAPDH and 18S. RT-qPCR amplification enabled the analysis of the gene expression of AMPK, FOXP2, WNT3, NPHP4, NPY2R, and PLXNA1 in neonatal saliva. Expression results were correlated with the feeding status during sample collection. Conclusions: In summary, the genes AMPK, FOXP2, WNT3, NPHP4, NPY2R, and PLXNA1 play critical roles in regulating oral feeding and the development of premature infants. Understanding the influence of these genes can provide valuable insights for improving nutritional care and support the development of these vulnerable babies. Evidence suggests that saliva-based gene expression analysis in newborns holds great promise for early detection and monitoring of disease and understanding developmental processes. More research and standardization of protocols are needed to fully explore the potential of saliva as a noninvasive biomarker in neonatal care.
Genome-Wide Identification and Characterization of CCT Gene Family from Microalgae to Legumes
Authors: Xu Yi , Yao Huiying , Lan Yanhong , Cao Yu , Xu Qingrui , Xu Hui , Qiao Dairong , Cao Yi
Published: July 2024

The CCT (CO, COL and TOC1) gene family has been elucidated to be involved in the functional differentiation of the products in various plant species, but their specific mechanisms are poorly understood. In the present investigation, we conducted a genome-wide identification and phylogenetic analysis of CCT genes from microalgae to legumes. A total of 700 non-redundant members of the CCT gene family from 30 species were identified through a homology search. Phylogenetic clustering with Arabidopsis and domain conservation analysis categorized the CCT genes into three families. Multiple sequence alignment showed that the CCT domain contains important amino acid residues, and each CCT protein contains 24 conserved motifs, as demonstrated by the motif analysis. Whole-genome/segment duplication, as well as tandem duplication, are considered to be the driving forces in the evolutionary trajectory of plant species. This comprehensive investigation into the proliferation of the CCT gene family unveils the evolutionary dynamics whereby WGD/segment duplication is the predominant mechanism contributing to the expansion of the CCT genes. Meanwhile, the examination of the gene expression patterns revealed that the expression patterns of CCT genes vary in different tissues and at different developmental stages of plants, with high expression in leaves, which is consistent with the molecular regulation of flowering in photosynthesis by CCT. Based on the protein–protein interaction analysis of CCT genes in model plants, we propose that the CCT gene family synergistically regulates plant development and flowering with light-signaling factors (PHYs and PIFs) and MYB family transcription factors. Understanding the CCT gene family’s molecular evolution enables targeted gene manipulation for enhanced plant traits, including optimized flowering and stress resistance.
In Silico Prediction of BRCA1 and BRCA2 Variants with Conflicting Clinical Interpretation in a Cohort of Breast Cancer Patients
Authors: Stella Stefania , Vitale Silvia Rita , Massimino Michele , Martorana Federica , Tornabene Irene , Tomarchio Cristina , Drago Melissa , Pavone Giuliana , Gorgone Cristina , Barone Chiara , Bianca Sebastiano , Manzella Livia
Published: July 2024

Germline BRCA1/2 alteration has been linked to an increased risk of hereditary breast and ovarian cancer syndromes. As a result, genetic testing, based on NGS, allows us to identify a high number of variants of uncertain significance (VUS) or conflicting interpretation of pathogenicity (CIP) variants. The identification of CIP/VUS is often considered inconclusive and clinically not actionable for the patients’ and unaffected carriers’ management. In this context, their assessment and classification remain a significant challenge. The aim of the study was to investigate whether the in silico prediction tools (PolyPhen-2, SIFT, Mutation Taster and PROVEAN) could predict the potential clinical impact and significance of BRCA1/2 CIP/VUS alterations, eventually impacting the clinical management of Breast Cancer subjects. In a cohort of 860 BC patients, 10.6% harbored BRCA1 or BRCA2 CIP/VUS alterations, mostly observed in BRCA2 sequences (85%). Among them, forty-two out of fifty-five alterations were predicted as damaging, with at least one in silico that used tools. Prediction agreement of the four tools was achieved in 45.5% of patients. Moreover, the highest consensus was obtained in twelve out of forty-two (28.6%) mutations by considering three out of four in silico algorithms. The use of prediction tools may help to identify variants with a potentially damaging effect. The lack of substantial agreement between the different algorithms suggests that the bioinformatic approaches should be combined with the personal and family history of the cancer patients.
Is Having Urban Green Space in the Neighborhood Enough to Make a Difference? Insights for Healthier City Design
Authors: Bressane Adriano , Ferreira Maria Eduarda Guedes , Garcia Ana Júlia da Silva , Medeiros Líliam César de Castro
Published: July 2024

Background: Prior research indicates that engagement with nature is associated with mental well-being; however, the impact of accessibility to urban green spaces (UGS) with suitable infrastructure for visitation and physical activities, like leisure or recreation, remains underexplored, particularly in developing countries. Purpose: This study delves into whether merely having green space in the neighborhood is sufficient to impact residents’ mental health in Brazilian metropolitan regions. Method: Utilizing a cross-sectional survey, data were collected from 2136 participants. The analyzed variables included the intensity, duration, and frequency of nature engagement, suitability of UGS for visitation and physical activities, and mental well-being indicators measured by the DASS-21 scale. Multivariate statistical analyses and multiple regression models were employed to verify hypothetical relationships. Results and conclusions: Higher intensity, duration, and frequency of nature engagement in UGS were significantly associated with lower depression, anxiety, and stress scores. Notably, having urban UGS in the neighborhood alone was not enough to reduce mental health issues. Practical implications: The findings point out the need for urban planning policies that prioritize the development of high-quality, accessible green spaces to maximize mental well-being benefits. These insights could inform city designs that foster healthier urban environments. Future directions: Longitudinal studies are needed to establish causality between nature engagement and mental health improvements. Further research should incorporate objective measures of nature engagement and explore more aspects of green space quality, such as biodiversity and amenities.
Polymorphism of an Nα-Aroyl-N-Aryl-Phenylalanine Amide: An X-ray and Electron Diffraction Study
Authors: Lang Markus , Goddard Richard , Patzer Michael , Ganapathy Uday S. , Dick Thomas , Richter Adrian , Seidel Rüdiger W.
Published: July 2024

In view of the rise of drug-resistant tuberculosis and difficult-to-treat related diseases caused by non-tuberculous mycobacteria, there is an urgent need for antimycobacterial drug discovery. Nα-aroyl-N-aryl-phenylalanine amides (AAPs) have been identified as antimycobacterial agents and are subject to lead optimization. The aim of the present study is to evaluate the impact of N-aryl ortho cyano substitution in a lead compound on the crystal and molecular structure and its in vitro activity against Mycobacterium abscessus. The title AAP can be conveniently synthesized from N-Boc-protected d-phenylalanine in two amide coupling steps using a previously established racemization-free method. Two polymorphic forms in the solid-state are described, as discovered by X-ray and electron diffraction. The introduction of a cyano group in the ortho position of the AAP N-aryl ring, however, leads to loss of in vitro activity against M. abscessus subsp. abscessus.
Diisoamyl (1R, 4S)-7-oxabicyclo[2.2.1]hept-5-ene-2,3-dicarboxylate
Authors: Quillian Brandon , Musso Kennedy , Vinson Elizabeth M. , Bazemore Joseph G. , Marks Allison R. , Padgett Clifford W.
Published: July 2024

Diisoamyl (1R,4S)-7-oxabicyclo[2.2.1]hept-5-ene-2,3-dicarboxylate (2) was prepared by reacting exo-7-oxabicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic anhydride (1) with isoamyl alcohol in the presence of a sulfuric acid catalyst under sonication conditions. Compound 2 was characterized by 1H, 13C NMR, DEPT-135, infrared, and UV-vis spectroscopy. Gas chromatography–mass spectrometry, elemental analysis, and melting point determination were used to assess purity. The structure of compound 2 was also determined by single-crystal X-ray diffraction. It crystallizes in the monoclinic space group P21/c (14) with cell values of a = 15.5647(3) Å, b = 12.8969(2) Å, c = 9.0873(2) Å; β= 99.3920(10)°.
Link between the Reactivity of Slag and the Strength Development of Calcium Aluminate Cement
Authors: Skočibušić Pejić Josipa , Bašić Alma-Dina , Grubor Martina , Serdar Marijana
Published: July 2024

The problem of loss of strength caused by the conversion reaction with calcium aluminate cements (CAC) is well known. It has been shown that the addition of ground granulated blast furnace slag (GGBS) to CAC inhibits the conversion process. Different slags can have a different chemical and mineralogical composition depending on their origin and production process, which can significantly influence their reactivity. This work investigated the extent to which the R3 test, developed for Portland cement and based on isothermal calorimetry and/or bound water, was used to predict the reactivity of ground granulated blast furnace slag in a CAC. Mortars and cement pastes with a 30% replacement of slag were tested to evaluate their compressive strength and microstructure. The results show that slags with higher reactivity due to their hydraulic properties lead to a lower compressive strength loss within the first 6 h, a higher strength loss after 24 h due to stratlingite formation and a lower strength loss after 28 days due to pozzolanic reaction and stratlingite formation. The results also confirm that the R3 test was used as a rapid method to predict the effects of slag on the compressive strength of CAC.
Effects of Mean Normal Stress and Microstructural Properties on Deformation Properties of Ultrahigh-Strength TRIP-Aided Steels with Bainitic Ferrite and/or Martensite Matrix Structure
Authors: Sugimoto Koh-ichi , Shioiri Shoya , Kobayashi Junya
Published: July 2024

The effects of mean normal stress on the deformation properties such as the strain-hardening, strain-induced martensite transformation, and micro-void initiation behaviors of low-carbon ultrahigh-strength TRIP-aided bainitic ferrite (TBF), bainitic ferrite/martensite (TBM), and martensite (TM) steels were investigated to evaluate the various cold formabilities. In addition, the deformation properties were related to the microstructural properties such as the matrix structure, retained austenite characteristics, and second-phase properties. Positive mean normal stress considerably promoted strain-induced martensite transformation and micro-void initiation, with an increased strain-hardening rate in an early strain range in all steels. In TM steel, the primary martensite matrix structure suppressed the micro-void initiation through high uniformity of a primary martensite matrix structure and a low strength ratio, although the strain-induced transformation was promoted, and a large amount of martensite/austenite constituent or phase was contained. A mixed matrix structure of bainitic ferrite/primary martensite in TBM steel also suppressed the micro-void initiation because of the refined microstructure and relatively stable retained austenite. Promoted micro-void initiation of TBF steel was mainly promoted by a high strength ratio.
Multiscale Simulation of Laser-Based Direct Energy Deposition (DED-LB/M) Using Powder Feedstock for Surface Repair of Aluminum Alloy
Authors: Zhou Xiaosong , Pei Zhenchao , Liu Zhongkui , Yang Lihang , Yin Yubo , He Yinfeng , Wu Quan , Nie Yi
Published: July 2024

Laser-based direct energy deposition (DED-LB/M) has been a promising option for the surface repair of structural aluminum alloys due to the advantages it offers, including a small heat-affected zone, high forming accuracy, and adjustable deposition materials. However, the unequal powder particle size during powder-based DED-LB/M can cause unstable flow and an uneven material flow rate per unit of time, resulting in defects such as pores, uneven deposition layers, and cracks. This paper presents a multiscale, multiphysics numerical model to investigate the underlying mechanism during the powder-based DED-LB/M surface repair process. First, the worn surfaces of aluminum alloy components with different flaw shapes and sizes were characterized and modeled. The fluid flow of the molten pool during material deposition on the worn surfaces was then investigated using a model that coupled the mesoscale discrete element method (DEM) and the finite volume method (FVM). The effect of flaw size and powder supply quantity on the evolution of the molten pool temperature, morphology, and dynamics was evaluated. The rapid heat transfer and variation in thermal stress during the multilayer DED-LB/M process were further illustrated using a macroscale thermomechanical model. The maximum stress was observed and compared with the yield stress of the adopted material, and no relative sliding was observed between deposited layers and substrate components.
Mechanical Properties of Rock Salt from the Kłodawa Salt Dome—A Statistical Analysis of Geomechanical Data
Authors: Kolano Malwina , Cała Marek , Stopkowicz Agnieszka
Published: July 2024

Rock salt is a potential medium for underground storage of energy resources and radioactive substances due to its physical and mechanical properties, distinguishing it from other rock media. Designing storage facilities that ensure stability, tightness, and safety requires understanding the geomechanical properties of rock salt. Despite numerous research efforts on the behaviour of rock salt mass, many cases still show unfavourable phenomena occurring within it. Therefore, the formulation of strength criteria in a three-dimensional stress state and the prediction of deformation processes significantly impact the functionality of storage in salt caverns. This article presents rock salt’s mechanical properties from the Kłodawa salt dome and a statistical analysis of the determined geomechanical data. The analysis is divided into individual mining fields (Fields 1–6). The analysis of numerical parameter values obtained in uniaxial compression tests for rock salt from mining Fields 1–6 indicates an average variation in their strength and deformation properties. Upon comparing the results of Young’s modulus (E) with uniaxial compressive strength (UCS), its value was observed with a decrease in uniaxial compressive strength (E = 4.19968·UCS2, R-square = −0.61). The tensile strength of rock salt from mining Fields 1–6 also exhibits moderate variability. An increasing trend in tensile strength was observed with increased bulk density (σt = 0.0027697·ρ − 4.5892, r = 0.60). However, the results of triaxial tests indicated that within the entire range of normal stresses, the process of increasing maximum shear stresses occurs linearly ((σ1 − σ3)/2 = ((σ1 + σ3)/2)·0.610676 + 2.28335, r = 0.92). A linear relationship was also obtained for failure stresses as a function of radial stresses (σ1 = σ3·2.51861 + 32.9488, r = 0.73). Based on the results, the most homogeneous rock salt was from Field 2 and Field 6, while the most variable rock salt was from Field 3.
Study of Eddy Current Testing Ability on SLM Aluminium Alloy
Authors: Geľatko Matúš , Hatala Michal , Botko František , Vandžura Radoslav , Hajnyš Jiří
Published: July 2024

The detection of defects in aluminium alloys using eddy current testing (ECT) can be restricted by higher electrical conductivity. Considering the occurrence of discontinuities during the selective laser melting (SLM) process, checking the ability of the ECT method for the mentioned purpose could bring simple and fast material identification. The research described here is focused on the application of three ECT probes with different frequency ranges (0.3–100 kHz overall) for the identification of artificial defects in SLM aluminium alloy AlSi10Mg. Standard penetration depth for the mentioned frequency range and identification abilities of used probes expressed through lift-off diagrams precede the main part of the research. Experimental specimens were designed in four groups to check the signal sensitivity to variations in the size and depth of cavities. The signal behavior was evaluated according to notch-type and hole-type artificial defects’ presence on the surface of the material and spherical cavities in subsurface layers, filled and unfilled by unmolten powder. The maximal penetration depth of the identified defect, the smallest detectable notch-type and hole-type artificial defect, the main characteristics of signal curves based on defect properties and circumstances for distinguishing between the application of measurement regime were stated. These conclusions represent baselines for the creation of ECT methodology for the defectoscopy of evaluated material.
Optimization Design of Laser Arrays Based on Absorption Spectroscopy Imaging for Detecting Temperature and Concentration Fields
Authors: Fan Limei , Dong Fangxu , Duan Jian , Sun Yan , Wang Fei , Liu Junyan , Tang Zhenhe , Sun Liangwen
Published: July 2024

Detecting temperature and concentration fields within engine combustors holds paramount significance in enhancing combustion efficiency and ensuring operational safety. Within the realm of engine combustors, the laminar absorption spectroscopy technique has garnered considerable attention. Particularly crucial is the optimization of the optical path configuration to enhance the efficacy of reconstruction. This study presents a flame parameter field reconstruction model founded on laminar absorption spectroscopy. Furthermore, an optimization approach for refining the optical path configuration is delineated. In addressing non-axisymmetric flames, the simulated annealing algorithm (SA) and Harris’s Hawk algorithm (HHO) are employed to optimize the optical path layout across varying beam quantities. The findings underscore a marked reduction in imaging errors with the optimized optical path configuration compared to conventional setups, thereby elevating detection precision. Notably, the HHO algorithm demonstrates superior performance over the SA algorithm in terms of optimization outcomes and computational efficiency. Compared with the parallel optical path, the optimized optical path of the HHO algorithm reduces the temperature field error by 25.5% and the concentration field error by 26.5%.
The Stamping Method Utilizing a Double-Trough Die in Microforming to Enhance Formability
Authors: Hsu Ming-Hung , Huang Kuo-Ming , Chang Chuan-Hsaing , Liu Chung-Ping
Published: July 2024

Currently, the field of microgear manufacturing faces various processing challenges, particularly in terms of size reduction; these challenges increase the complexity and costs of manufacturing. In this study, a technique for microgear manufacturing is aimed at reducing subsequent processing steps and enhancing material utilization. This technique involves the use of trough dies with extrusion-cutting processing, which enables workpieces to undergo forming in a negative clearance state, thus reducing subsequent processing time for micro products. We conducted finite element simulations using microgear dies, measuring stress, velocity, and flow during the forming process of four types of dies-flat, internal-trough, external-trough, and double-trough dies. The results indicated that the buffering effect of the troughs reduced the rate of increase in the material’s internal stress. In the cavity, the material experiences a significant increase in hydrostatic pressure, leading to the formation of a “hydrostatic pressure wall”. This pressure barrier imposes substantial constraints on the flow of the material during dynamic processes, making it difficult for the material to move into the remaining areas. This effectively enhances the blockage of material flow, demonstrating the critical role of hydrostatic pressure in controlling material distribution and movement. In addition, combining the characteristics of both into a double-trough die enhances the overall stability of forming velocity, reduces forming load and energy consumption, and maximizes material utilization. Results further revealed that microgears manufactured using double-trough dies exhibited defect-free surfaces, with a dimensional error of less than 5 μm and tolerances ranging from IT5 to IT6. Overall, this study offers new insights into the traditional field of microgear manufacturing, highlighting potential solutions for the challenges encountered in current microstamping processes.
Construction and Content Validation of Mobile Devices’ Application Messages about Food and Nutrition for DM2 Older Adults
Authors: Dusi Rafaella , Trombini Raiza Rana de Souza Lima , Pereira Alayne Larissa Martins , Funghetto Silvana Schwerz , Ginani Verônica Cortez , Stival Marina Morato , Nakano Eduardo Yoshio , Zandonadi Renata Puppin
Published: July 2024

Older adults face a decline in the quality of their diet, which affects their health. The prevalence of DM2 is increasing, as are the associated complications. Effective nutrition education and mobile health (mHealth) interventions offer a viable solution in the scenario of the widespread use of mobile devices. This study aimed to develop and validate messages for a mobile application aimed at older adult Brazilians with DM2 who receive care at the Brazilian Unified Health System (SUS). The educational messages on healthy eating for older adults with DM2 were created from 189 excerpts selected from Brazilian official documents. A total of 37 messages were created, categorized into 20 educational, 12 motivational, and 5 congratulatory, all up to 120 characters. Twenty-one experts validated the messages for clarity and relevance, and 11 messages had to be revised to meet the criteria. Subsequently, the 36 messages approved by the experts were tested on a sample of 57 older adults, guaranteeing clarity rates of over 80%. This study developed and validated 36 messages for a mobile health app aimed at older adults with type 2 diabetes mellitus in Brazil. Expert evaluation ensured clarity and relevance, confirmed by older adult participants who evaluated clarity. This research highlights the potential of mHealth to overcome barriers to accessing healthcare in the SUS, emphasizing personalized interventions for the effective management of older adults’ health.
Self-Regulation in Eating Behaviors: The Role of Executive Function in Response to Food Stimuli
Authors: Favieri Francesca , Tambelli Renata , Chen Eunice , Casagrande Maria
Published: July 2024

Human nutrition is characterized by both automatic and self-regulated processes. One of the dimensions that may be employed in monitoring eating behaviors is the cognitive control played by the executive functions (EFs). The role of EFs in affecting eating behaviors has been assessed in empirical studies, but further analyses are needed in a current society characterized by a food-abundant environment. Accordingly, this study attempted to evaluate the association between weight status and executive functions in response to food-related stimuli. One hundred and forty-four young adults took part in the study (25.7% in overweight condition). The participants completed a set of computerized cognitive tasks to assess cognitive and motor inhibition and working memory in two different conditions: (i) classic versions of the tasks and (ii) modified versions with food cues. The results indicate that food stimuli may influence executive performance and that there is an association between food cue-related executive functioning, particularly in the domain of motor inhibition, and working memory. These results suggest that self-regulation in nutrition may involve executive control. Although further studies are needed, this work suggests the importance of a multidimensional perspective in the analysis of eating behaviors and the relevance of EFs in monitoring our approach to food stimuli in an environmental context.
Coffee with Cordyceps militaris and Hericium erinaceus Fruiting Bodies as a Source of Essential Bioactive Substances
Authors: Kała Katarzyna , Cicha-Jeleń Małgorzata , Hnatyk Kamil , Krakowska Agata , Sułkowska-Ziaja Katarzyna , Szewczyk Agnieszka , Lazur Jan , Muszyńska Bożena
Published: July 2024

Drinking coffee is a daily routine for many people. Supplement manufacturers have proposed adding powdered Cordyceps militaris, known for its ergogenic and immunostimulating properties, and Hericium erinaceus, known for its nerve growth factor (NGF)-stimulating properties, to coffee. The aim of this work was to compare the bioactive substances in three types of coffee: machine-brewed, instant, and traditionally brewed, prepared with the addition of H. erinaceus and C. militaris fruiting bodies. The analysis of bioactive substances was performed using AAS and RP-HPLC methods. Among the control samples of coffee, traditionally brewed coffee was the best source of bioelements. Considering the mushroom species tested, the best additional source of Mg, Zn, Cu, Na, K, and Ca was C. militaris. A slightly higher Fe content was determined for H. erinaceus. With the addition of C. militaris, the amounts of 4-feruloylquinic acid (18.6 mg/200 mL) and 3,5-di-caffeoylquinic acid (3.76 mg/200 mL) also increased. In conclusion, the C. militaris species has been proven to be a better source of bioactive substances as a coffee additive in the daily diet. The combination of brewed coffee and the tested mushrooms seems to be the most beneficial in terms of health-promoting effects.
Vascular Endothelial Growth Factor (VEGF) and VEGF Receptor Inhibitors in Health and Disease
Authors: Broussy Sylvain
Published: July 2024

In this Special Issue of Pharmaceuticals, we present four reviews and seven original articles addressing recent aspects of research on Vascular Endothelial Growth Factors (VEGFs) and their receptors, from clinical practice to fundamental studies in new drug development [...]
Analysis of Radio-Shaded Areas in the Geoje Island Sea Based on the Automatic Identification System (AIS)
Authors: Jung Bong-Kyu , Park Cheor-Hong , Choi Won-Sam , Kim Dong-Hyun
Published: July 2024

An automatic identification system (AIS) is often installed on merchant ships and fishing boats to prevent collisions and ensure safe navigation. The location information of ships transmitted from AIS equipment can help maritime traffic control prevent accidents. The southern coast of Korea comprises a complex coastline with numerous fishing boats and transit vessels. In particular, the Tongyeong and Geoje Islands include high-altitude mountains and islands, resulting in several radio-shaded areas where AIS signals cannot be received, owing to geographical effects. However, only a few studies have explored this region and performed practical experiments on the reception status of AIS locations in radio-shaded areas. In this study, we performed an experiment in the Geoje Island Sea on the southern coast to analyze the impact of high terrain on the reception rate and status of automatic identification devices. Two identical pieces of AIS equipment were installed to generate multiple radio waves, and the location data transmitted via different antennae were compared. The experimental analysis forms the basis for identifying the exact location of ships in the event of maritime accidents, facilitating rapid rescue. Moreover, the accuracy of the location transmitted by the AIS equipment can aid in detecting the cause of accidents.
Joint Emission-Dependent Optimal Production and Preventive Maintenance Policies of a Deteriorating Manufacturing System
Authors: Gharbi Ali , Kenné Jean-Pierre , Takengny Armel Leonel Kuegoua , Assid Morad
Published: July 2024

This paper addresses the problem of joint production and preventive maintenance (PM) planning of a deteriorating manufacturing system generating greenhouse gas (GHG) emissions. The system is composed of a deteriorating machine, subject to random failures and repairs evolving in a dynamic and stochastic context. The main objective is to develop control policies that minimize the sum of backlog, inventory, maintenance, and emission costs. The stochastic optimal control theory based on the dynamic programming approach is used to obtain the optimality conditions and the optimal control policies, which are determined using numerical methods. Sensitivity analyses are provided to depict and validate the obtained structure of the production and PM policies characterized by multiple thresholds that jointly regulate the production and PM rates with the age, emissions, and inventory levels. Furthermore, we compared the performance of the obtained control policies with that of the most relevant policies found in the literature and showed their superiority by considerable cost savings. Finally, the proposal’s implementation is provided to equip managers of the considered manufacturing system with an effective and robust decision-support tool.
Framework for Integration of Health Monitoring Systems in Life Cycle Management for Aviation Sustainability and Cost Efficiency
Authors: Kabashkin Igor , Perekrestov Vladimir , Tyncherov Timur , Shoshin Leonid , Susanin Vitalii
Published: July 2024

In the development of the aviation industry, integrating Life Cycle Management (LCM) with Advanced Health Monitoring Systems (AHMSs) and modular design emerges as a pivotal strategy for enhancing sustainability and cost efficiency. This paper examines how AHMSs, using the Internet of Things, artificial intelligence, and blockchain technologies, can transform maintenance operations by providing real-time diagnostics, predictive maintenance, and secure data logging. The study introduces a comprehensive framework that integrates these technologies into LCM, focusing on maximizing the utilization and lifespan of aircraft components. Quantitative models are developed to compare traditional and modern aviation systems, highlighting the substantial life cycle cost savings and operational efficiencies achieved through these integrations. The results demonstrate up to a 30% reduction in maintenance costs and up to a 20% extension in component lifespan, validating the economic and operational benefits of the proposed integrations. The research underscores the potential of these combined strategies to advance the aviation sector’s sustainability objectives, and serves as valuable tools for industry stakeholders, offering actionable insights into the implementation of LCM strategies enhanced by AHMSs and modular design, offering a detailed analysis of the practical implementation challenges.