bluuebunny/crossref_metadata_2025 huggingface dataset:
PROTA: A Robust Tool for Protamine Prediction Using a Hybrid Approach of Machine Learning and Deep Learning
Authors: Farias Jorge G. , Herrera-Belén Lisandra , Jimenez Luis , Beltrán Jorge F.
Published: September 2024

Protamines play a critical role in DNA compaction and stabilization in sperm cells, significantly influencing male fertility and various biotechnological applications. Traditionally, identifying these proteins is a challenging and time-consuming process due to their species-specific variability and complexity. Leveraging advancements in computational biology, we present PROTA, a novel tool that combines machine learning (ML) and deep learning (DL) techniques to predict protamines with high accuracy. For the first time, we integrate Generative Adversarial Networks (GANs) with supervised learning methods to enhance the accuracy and generalizability of protamine prediction. Our methodology evaluated multiple ML models, including Light Gradient-Boosting Machine (LIGHTGBM), Multilayer Perceptron (MLP), Random Forest (RF), eXtreme Gradient Boosting (XGBOOST), k-Nearest Neighbors (KNN), Logistic Regression (LR), Naive Bayes (NB), and Radial Basis Function-Support Vector Machine (RBF-SVM). During ten-fold cross-validation on our training dataset, the MLP model with GAN-augmented data demonstrated superior performance metrics: 0.997 accuracy, 0.997 F1 score, 0.998 precision, 0.997 sensitivity, and 1.0 AUC. In the independent testing phase, this model achieved 0.999 accuracy, 0.999 F1 score, 1.0 precision, 0.999 sensitivity, and 1.0 AUC. These results establish PROTA, accessible via a user-friendly web application. We anticipate that PROTA will be a crucial resource for researchers, enabling the rapid and reliable prediction of protamines, thereby advancing our understanding of their roles in reproductive biology, biotechnology, and medicine.
Antioxidant and Antibacterial Activities of Selected Medicinal Plants from Addis Ababa against MDR-Uropathogenic Bacteria
Authors: Eyasu Mebrahtu , Benedí Juana , Romero José Antonio , Martín-Aragón Sagrario
Published: September 2024

This study determined the antioxidant and antibacterial activities of Thymus schimperi (Ts), Rhamnus prinoides (Rp), and Justicia schimperiana (Js) from Addis Ababa against MDR-Uropathogenic bacteria. Accordingly, Thymus schimperi had the highest total phenolic (TPC), flavonoid (TFC) and proanthocyanidin content. In Ts, the GC-MS analyses predicted 14 bioactive compounds. And among these, hexanedioic acid, bis(2-ethylhexyl) ester, thymol, and o-cymen-5-ol were the most predominant compounds, respectively. Six compounds were also predicted in Rp, where hexanedioic acid, bis(2-ethylhexyl) ester, β-D-glucopyranoside, methyl, and desulphosinigrin were the predominant, respectively. Whereas in the Js extract, five bioactive compounds were predicted, with hexanedioic acid, mono (2-ethylhexyl) ester, debrisoquine, and 8,11,14-heptadecatrienoate, methyl ester being predominant compounds, respectively. The extracts’ TPC showed a strong negative correlation with the DPPH (2,2-diphenyl-1-picrylhydrazyl) assay (r = −0.999; p = 0.023). In addition, the TFC correlated significantly with the ABTS (2,2′-azino-di-(3-ethylbenzthiazoline sulfonic acid)) assay (r = 0.999; p = 0.032). Thymus schimperi showed the highest antibacterial activity against clinical isolates of Escherichia coli and Klebsiella pneumoniae ESBL at 1000 mg/mL, and Ts had the lowest MIC (4 mg/mL) among evaluated extracts against E. coli (ATCC25922). In conclusion, Ts and Rp possess higher predicted bioactive molecules, including antioxidant and antibacterial activities, which are potentially useful in treating urinary tract infections.
Development History, Structure, and Function of ASR (Abscisic Acid-Stress-Ripening) Transcription Factor
Authors: Zhang Yue , Wang Mengfan , Kitashov Andery V. , Yang Ling
Published: September 2024

Abiotic and biotic stress factors seriously affect plant growth and development. The process of plant response to abiotic stress involves the synergistic action of multiple resistance genes. The ASR (Abscisic acid stress-ripening) gene is a plant-specific transcription factor that plays a central role in regulating plant senescence, fruit ripening, and response to abiotic stress. ASR family members are highly conserved in plant evolution and contain ABA/WBS domains. ASR was first identified and characterized in tomatoes (Solanum lycopersicum L.). Subsequently, the ASR gene has been reported in many plant species, extending from gymnosperms to monocots and dicots, but lacks orthologues in Arabidopsis (Arabidopsis thaliana). The promoter regions of ASR genes in most species contain light-responsive elements, phytohormone-responsive elements, and abiotic stress-responsive elements. In addition, ASR genes can respond to biotic stresses via regulating the expression of defense genes in various plants. This review comprehensively summarizes the evolutionary history, gene and protein structures, and functions of the ASR gene family members in plant responses to salt stress, low temperature stress, pathogen stress, drought stress, and metal ions, which will provide valuable references for breeding high-yielding and stress-resistant plant varieties.
Exogenous Application of dsRNA—Inducing Silencing of the Fusarium oxysporum Tup1 Gene and Reducing Its Virulence
Authors: Fan Sen , Zhou Yanguang , Zhu Na , Meng Qingling , Zhao Yujin , Xu Jingyan , Tang Yunjia , Dai Shijie , Yuan Xiaofeng
Published: September 2024

Fusarium oxysporum is a widespread soil-borne fungal pathogen that can infect various plants, causing wilt and root rot diseases. The root rot disease of Atractylodes macrocephala caused by F. oxysporum is among the most serious diseases associated with continuous cropping, significantly hindering its sustainable development. In this study, we aimed to investigate the effect of exogenous application of double-stranded RNA (dsRNA) on silencing the F. oxysporum Tup1 gene to reduce its virulence and to evaluate its potential application in controlling root rot disease in A. macrocephala. The Tup1 gene was amplified from the F. oxysporum genome, and different lengths of Tup1-dsRNA were designed and synthesized. The uptake of dsRNA by the fungus was verified using Tup1-dsRNA labeled with fluorescein, and in vitro dsRNA treatment experiments were conducted to assess its impact on the growth and virulence of F. oxysporum. Additionally, Tup1-dsRNA was applied to the roots of A. macrocephala to evaluate its effectiveness in controlling root rot disease. The experimental results showed that F. oxysporum could effectively uptake exogenously applied Tup1-dsRNA, significantly reducing Tup1 gene expression. All lengths of Tup1-dsRNA inhibited fungal growth and caused morphological changes in the fungal hyphae. Further plant experiments and Reverse Transcription Quantitative Polymerase Chain Reaction (RT-qPCR) analysis indicated that Tup1-dsRNA treatment significantly reduced the incidence of root rot disease in A. macrocephala, which was supported by the reduction in peroxidase (POD) and catalase (CAT) enzyme activities, malondialdehyde (MDA) content, and proline (Pro) levels in treated root tissues. This study demonstrated that exogenous dsRNA could reduce the virulence of F. oxysporum by silencing the Tup1 gene and effectively mitigate the root rot disease it causes in A. macrocephala. The successful application of Tup1-dsRNA provided strong evidence for the potential of RNA interference (RNAi) technology in plant disease control. Future research could further optimize the design and application of dsRNA to enhance its practical value in agriculture.
Charge Traps in Wide-Bandgap Semiconductors for Power Electronics Applications
Authors: Lee Kean Chuan , Weis Martin
Published: September 2024

Wide-bandgap semiconductors have been envisioned for power electronics applications because of their ability to operate at higher temperatures and higher applied voltages without breakdown. However, the presence of defects may cause device failure, necessitating a comprehensive understanding of material defects. This review provides a fingerprint of known defects in three envisioned semiconductors for power electronics: 4H-SiC, GaN, and β-Ga2O3. Via a detailed discussion of defects—the origins of electrically active charge traps—through their activation energies and capture cross-sections, we provide important insights into defect parameter distributions. This review not only serves as a reference but also offers a strategic roadmap for distinguishing between similar defects. Such knowledge is key for the development of more robust and efficient power electronic devices that can fully exploit the potential of wide-bandgap semiconductors.
A High-Precision, Ultra-Short Baseline Positioning Method for Full Sea Depth
Authors: Liu Yeyao , Xue Jingfeng , Wang Wei
Published: September 2024

To fulfill the demand for high-precision underwater acoustic positioning at full sea depth, an ultra-short baseline (USBL) positioning method with the square array based on the least squares estimating signal parameters via rotational invariance techniques (LS-ESPRIT) algorithm is presented in this paper. A combination of beam tracking and beamforming is employed to improve the accuracy of direction-of-arrival (DOA) estimation and, consequently, enhance overall positioning accuracy. In order to mitigate the issue of position jumping resulting from phase ambiguity in traditional four-element cross arrays, we have improved the stability of the positioning algorithm by utilizing a multi-element square array and employing the LS-ESPRIT algorithm for DOA estimation. Furthermore, the signal detection method integrating the correlation coefficient and ascending/descending chirp signals is employed to enhance the reliability of the location algorithm. Simulation analysis and experimental results demonstrate that the proposed algorithm effectively enhances positioning accuracy and improves the problem of jumping in positioning results.
First Confirmed Description of Acremonium egyptiacum from Greece and Molecular Identification of Acremonium and Acremonium-like Clinical Isolates
Authors: Arabatzis Michael , Abel Philoktitis , Sotiriou Eleni , Velegraki Aristea
Published: September 2024

Acremonium and the recently separated acremonium-like genera, such as Sarocladium, are emerging causes of opportunistic disease in humans, mainly post-traumatic infections in immunocompetent hosts, but also invasive infections in immunocompromised patients, such as those undergoing transplantation. Acremonium egyptiacum has emerged as the major pathogenic Acremonium species in humans, implicated mainly in nail but also in disseminated and organ specific infections. In this first study of acremonium-like clinical isolates in Greece, 34 isolates were identified and typed by sequencing the internal transcribed spacer, and their antifungal susceptibility was determined by a modified CLSI standard M38 3rd Edition method for filamentous fungi. A. egyptiacum was the primary species (18 isolates) followed by Sarocladium kiliense (8), Acremonium charticola, Gliomastix polychroma, Proxiovicillium blochii, Sarocladium terricola, Sarocladium zeae, and Stanjemonium dichromosporum (all with one isolate). Two isolates, each with a novel ITS sequence, possibly represent undescribed species with an affinity to Emericellopsis. All three A. egyptiacum ITS barcode types described to date were identified, with 3 being the major type. Flutrimazole, lanoconazole, and luliconazole presented the lower minimum inhibitory concentration (MIC) values against A. egyptiacum, with a geometric mean (GM) MIC of 2.50, 1.92, and 1.57 μg/mL, respectively. Amphotericin B, itraconazole, posaconazole, voriconazole, terbinafine, amorolfine, and griseofulvin MICs were overall high (GM 12.79–29.49 μg/mL). An analysis of variance performed on absolute values showed that flutrimazole, lanoconazole, and luliconazole were equivalent and notably lower than those of all the other drugs tested against A. egyptiacum. Antifungal susceptibility of the three different A. egyptiacum genotypes was homogeneous. Overall, the high MICs recorded for all systemically administered drugs, and for some topical antifungals against the tested A. egyptiacum and other acremonium-like clinical isolates, justify the routine susceptibility testing of clinical isolates.
Roles of Three FgPel Genes in the Development and Pathogenicity Regulation of Fusarium graminearum
Authors: Cai Lu , Xu Xiao , Dong Ye , Jin Yingying , Rashad Younes M. , Ma Dongfang , Gu Aiguo
Published: September 2024

Fusarium head blight (FHB) is a devastating fungal disease caused by Fusarium graminearum. Pectin lyase, a pectinase, acts on the α-1,4-glycosidic linkage of galacturonic acid primarily by β-elimination. In this study, three pectin lyase genes (FgPel1, 2, 3) in F. graminearum were selected, and deletion mutants (ΔFgPel1, 2, 3) were constructed by homologous recombination for functional characterization. The gene deletions affected the morphology and growth rate of F. graminearum on pectin medium at various concentrations, with the growth rate of ΔFgPel1 being more significant. The growth of ΔFgPel1 colonies slowed at pH 4, with optimal growth at pH 6.5, whereas ΔFgPel2 and ΔFgPel3 exhibited greater inhibition at pH 8. Colony morphology and diameter of the deletion mutants showed no significant differences compared to the wild-type strain PH-1, and there was no effect on conidial production or germination rate. Pathogenicity assays demonstrated that gene deletion significantly reduced the ability of F. graminearum to infest corn silks and wheat ears, and that ΔFgPel2 showed a more pronounced reduction in pathogenicity on wheat spikes. In summary, the pectin lyase genes (FgPel1, 2, 3) are involved in pectin utilization and are influenced by external pH conditions, which attenuate the pathogenicity of F. graminearum without affecting its vegetative growth or asexual spore formation. These findings elucidate the roles of these genes and provide a basis for controlling FHB.
Human Trafficking and Gender Inequality: How Businesses Can Lower Risks and Costs
Authors: Ariail Donald L. , Smith Katherine Taken , Smith Lawrence Murphy
Published: September 2024

Human trafficking continues to be a profitable multi-billion dollar business. People are either callous toward human rights or they are unaware of the crime occurring. Many businesses may unknowingly facilitate human trafficking by providing services, such as transportation, hotels, or haircuts, or purchasing products from unfamiliar sources that secretly use forced labor. To be socially responsible, a business must establish effective enterprise governance policies that help prevent and detect trafficking. A business can incur legal fines, damage to its reputation, incur lost business, and be subject to litigation, all as a result of human trafficking. Worldwide, estimates are that 50 million people are being trafficked. Human trafficking is especially harmful to females, both adult women and girls, who comprise about 70 percent of all trafficking victims. Gender theory helps explain this disproportionate impact on women. This study provides an overview of human trafficking, an empirical analysis of the relationship of gender inequality to trafficking, and specific steps that a business can take to help prevent this crime, protect its reputation, and avoid fines and lost business.
Character Counts: Psychometric-Based Credit Scoring for Underbanked Consumers
Authors: Fine Saul
Published: September 2024

Psychometric-based credit scores measure important personality traits that are characteristic of good borrowers’ behaviors. While such data can potentially improve credit models for underbanked consumers, the utility of psychometric data in consumer lending is still largely understudied. The present study contributes to the literature in this respect, as it is one of the first studies to evaluate the efficacy of psychometric-based credit scores for predicting future loan defaults among underbanked consumers. The results from two culturally diverse samples of loan applicants (Sub-Saharan Africa, n = 1113; Western Europe, n = 1033) found that psychometric scores correlated significantly with future loan defaults (Gini = 0.28–0.31) and were incrementally valid above and beyond the banks’ own credit scorecards. These results highlight the theoretical basis for personality in financial behaviors, as well as the practical utility that psychometric scores can have for credit decisioning in general and the facilitation of financial inclusion for underbanked consumer groups in particular.
¿Soy de Ribera o Rivera?: Sociolinguistic /b/-/v/ Variation in Rivera Spanish
Authors: Araujo Vanina Machado , Ward Owen
Published: September 2024

This study investigates the impact of language contact on three generations of bilingual Spanish and Uruguayan Portuguese speakers in Rivera City, Uruguay, located on the Uruguayan–Brazilian border. Focusing on the confirmed presence of the Portuguese-like/b/and/v/phonemic distinction, and the lower frequency of the Montevideo Spanish-like approximantized stops in Riverense Spanish (RS), the research examines the production of  and  in 29 female Rivera Spanish bilinguals belonging to different age groups. More specifically, the aim was to see if the previously observed differential use of language-specific phonological variants could be accounted for by using precise measurements of relative intensity, duration, and voicing coupled with a distributional analysis of realizations derived from auditory coding. At the same time, their production is compared to that of 30 monolingual Montevideo Spanish (MS) speakers, who served as the control group, offering a first description of the production of  and  within this distinct Rioplatense Spanish variety. Riverense’s higher overall relative intensity, duration, and voicing values support auditory coding results, providing evidence of the expected phonological differences between both Uruguayan Spanish varieties. In particular, an exclusive presence of fricative/v/and less approximantization of/b/in RS speech exposed the influence of Portuguese in Rivera bilinguals and their divergence from MS. In addition, as predicted, the findings reveal a higher presence of Portuguese-like productions of [v] and [b] in older bilinguals when compared to younger generations. This illustrates a continuum from Portuguese-like forms to Spanish-like forms, which is confirmed by both acoustic and distributional analyses. Finally, evidence of the existence of innovative forms resulting from mixing Portuguese and Spanish phonological systems in RS are presented. This study’s findings contribute to sociolinguistics and bilingualism by exposing cross-linguistic influence in a border setting with rigorous analytical methods that offer reliable results and go beyond a basic analysis based on auditory identification.
Effects of Tempering on Microstructure and Properties of Additive Manufacturing Cu-Bearing AISI 431 Steel
Authors: Zhao Li , Li Baichun , Tan Chaolin , Zhu Hongmei
Published: September 2024

AISI 431 martensitic stainless steels (MSS) with 2.5 wt% Cu were fabricated via laser-directed energy deposition additive manufacturing followed by single-step tempering treatment. The influences of different tempering times at 600 °C on microstructure and mechanical properties of the as-deposited 431-2.5Cu MSS have been explored and analyzed. The as-deposited MSS specimen primarily consisted of lath martensite, austenite and M23C6 carbide. After the single-step tempering treatment at 600 °C, Cu-enriched (ԑ-Cu) nano-precipitates and reverse austenite can be formed and promoted by extending the tempering treatment. The microhardness, strength and elongation can be improved with increasing the tempering time up to 1.0 h, and subsequently reduced with the tempering time prolonging to 2.0 h. Compared to 431 MSS that requires a multiple-step heat treatment for excellent performance, the 431-2.5Cu MSS specimen presented superior tensile properties after single-step tempering at 600 °C for 1.0 h in the present work. The ultimate tensile strength (UTS), yield strength (YS) and elongation (EL) of one-hour tempered MSS were 1611 MPa, 1334 MPa and 16.3%, respectively. This study provides a quantitative theoretical reference and experimental basis for realizing short-process fabrication of the Cu-bearing MSS with high strength and ductility.
In Vitro Evaluation of Speed Sintering and Glazing Effects on the Flexural Strength and Microstructure of Highly Translucent Multilayered 5 mol% Yttria-Stabilized Zirconia
Authors: Jeong Ji-In , Kwon Yong-Hoon , Seol Hyo-Joung
Published: September 2024

This study aimed to investigate the impact of speed sintering and glazing on the flexural strength and microstructure of multilayered 5 mol% yttria-stabilized (5Y-) zirconia, which remains unknown. Bar-shaped specimens (N = 600) were fabricated from 5Y-zirconia (FX; Ceramill Zolid FX ML, ST; Katana STML) by cutting, polishing, sintering (conventional and speed sintering), and then glazing. A flexural strength test (n = 30/group), field emission scanning electron microscopy (FE-SEM) observation (n = 2/group), and an X-ray diffraction (XRD) study with Rietveld refinement (n = 1/group) were performed. The flexural strength was analyzed using three-way ANOVA and a post hoc Scheffé test. The grain size was analyzed using the Kruskal–Wallis H test and Bonferroni–Dunn post hoc test. Flexural strength slightly decreased in the nonglazed FX after speed sintering (p < 0.05). Glazing with and without glazing paste did not affect flexural strength at both sintering speeds (p > 0.05). Speed sintering and glazing minimally changed the Weibull modulus and phase fraction, and did not affect grain size (p > 0.05). ST had a larger grain size and lower tetragonal phase content than FX and had a lower flexural strength than FX in most groups (p < 0.05). Overall, the multilayered 5Y-zirconia is considered suitable for dental application using speed sintering and glazing.
Notches and Fatigue on Aircraft-Grade Aluminium Alloys
Authors: Zichil Valentin , Grigoras Cosmin Constantin , Ciubotariu Vlad Andrei
Published: September 2024

The influence of notches and fatigue on the ultimate tensile strength and elongation at break of aluminium alloys (2024-T3, 6061-T4, 6061-T4 uncoated, 6061-T6 uncoated, 7075-T0, and 7076-T6) is presented in this study. A total of 120 specimens were used. On all specimens, notches were made using a CNC machine, with 60 of them subjected to low-cycle fatigue (LCF) before undergoing the tensile test. Based on the statistical examination of the measured data, mathematical prediction models have been established. Compared to their unscratched counterparts, the results indicate a significant decrease in the UTS and elongation at break for both notched and notched-fatigued specimens. The LCF pre-treatment contributes to the negative impacts of the notches, resulting in reduced values for the UTS and elongation at break, thus concluding that surface integrity is critical for maintaining the structural strength of aircraft components.
Influence of Immersion Orientation on Microstructural Evolution and Deformation Behavior of 40Cr Steel Automobile Front Axle during Oil Quenching
Authors: Shi Yuanji , Wang Xiaowen , Dong Chengtong , Li Junwan , Chen Zeyu , Cheng Cheng
Published: September 2024

This study employs the finite element method to investigate the microstructural evolution and deformation behavior of a 40Cr steel automobile front axle during the quenching process. By establishing a multi-physics field coupling model, the study elucidates the variation patterns of the microstructure field in the quenching process of the front axle under different immersion orientations. It is found that along the length direction, the bainite and martensite structures decrease from the center to the edge region, while the ferrite structure shows an increasing trend. Additionally, the influence of immersion orientation on the hardness of the front axle’s microstructure and deformation behavior is thoroughly discussed. The results indicate that, firstly, when quenched horizontally, the hardness difference among different regions of the front axle is approximately 8.2 HRC, whereas it reaches 10.3 HRC when quenched vertically. Considering the uniformity of the microstructure, the horizontal immersion method is preferable. Secondly, due to the different immersion sequences in different regions of the front axle leading to varying heat transfer rates, as well as the different amounts of martensite structures obtained in different regions, the deformation decreases along the length direction from the center to the edge region. Horizontal immersion quenching, compared to vertical immersion, results in a reduction of approximately 56.2% and 48.9% in deformation on the representative central cross-section (A-A) and the total length of the front axle, respectively. Therefore, considering aspects such as microstructure uniformity and deformation, the horizontal immersion quenching orientation is more favorable.
Influence of Natural Fractures and Laminae on Fracture Propagation and Failure Mode of Continental Shale
Authors: Huang Beixiu , Qiao Sijia , Li Lihui , Gao Xiangbo , Li Xiao , Ranjith Pathegama Gamage
Published: September 2024

Natural fractures and laminae are well-developed in continental shale, which greatly affects the fracture propagation and failure mode. Based on the natural fractures and laminae developed in the outcrops of Triassic continental shale from the southern Ordos Basin, China, four different types of shale models are constructed in this research. The CASRock software V1.0 is utilized to conduct numerical simulations to investigate the influence of natural fractures and soft-to-hard laminae on the mechanical behavior of continental shale. The results demonstrate that the uniaxial compressive strength of shale models can improve by up to 34.48% when soft-to-hard laminae are present, but it can drop by up to 18.97% when weak interfaces are present. New fractures are consistently initiated at the ends of natural fractures, with various propagation patterns in different laminae. Fractures in soft laminae usually propagate in an oblique path at an angle β ≈ 20°–30° relative to the direction of compressive stress, manifesting as shear fractures. Fractures in medium-to-hard laminae tend to propagate parallel to compressive stress, primarily featuring tensile fractures. The ultimate fracture morphology becomes more complex as soft, medium, and hard laminae and weak interfaces occur successively. It changes from a nearly linear fracture to an echelon pattern with more secondary fractures and finally a network shape, with a total fracture area increase of up to 270.12%. This study reveals the combined effect of natural fractures, soft-to-hard laminae, and weak interfaces on the fracture propagation and failure model of continental shale, providing support for fracturing optimization based on shale’s authentic structure characteristics.
On the Creation of a Material Bond between L-PBF-Manufactured AZ91 and Ti-6Al-4V Components in the Context of Medical Applications
Authors: Grüger Lennart , Jensch Felix , Dittrich Fabian , Härtel Sebastian
Published: September 2024

Within the scope of these investigations, the feasibility of a material bond between Ti-6Al-4V and the magnesium alloy AZ91 is analyzed. Ti-6Al-4V is frequently used for implants due to its biocompatibility, corrosion resistance, and specific strength. However, depending on the surface quality, the attachment behavior of the bone to the implant varies. Magnesium implants promote the regeneration of bone tissue and biodegrade as the bone tissue heals. Combining the properties of both materials in one implant enables a reduced implant volume and increased stability. For this reason, this study aims to demonstrate the feasibility of creating a material bond between the materials Ti-6Al-4V and AZ91. For this purpose, Ti-6Al-4V truncated cones and AZ91 sleeves were produced using the additive manufacturing process of laser powder bed fusion (L-PBF). The as-built sleeves were then pressed onto machined truncated cones. Since zinc serves as a lubricant and has good diffusion properties with the materials used as a result of heat treatment, a comparison was made between zinc-coated and the as-built Ti-6Al-4V samples. This showed that a bond was created after hot isostatic pressing and that the push-out force could be increased by more than 4.5 times. Consequently, a proof of feasibility was demonstrated, and a high potential for applications in medical technology was shown.
In-Situ Construction of Fe-Doped NiOOH on the 3D Ni(OH)2 Hierarchical Nanosheet Array for Efficient Electrocatalytic Oxygen Evolution Reaction
Authors: Li Mengyang , Wang Mingran , Wang Qianwei , Cao Yang , Gao Jie , Wang Zhicheng , Gao Meiqi , Duan Guosheng , Cao Feng
Published: September 2024

Accessible and superior electrocatalysts to overcome the sluggish oxygen evolution reaction (OER) are pivotal for sustainable and low-cost hydrogen production through electrocatalytic water splitting. The iron and nickel oxohydroxide complexes are regarded as the most promising OER electrocatalyst attributed to their inexpensive costs, easy preparation, and robust stability. In particular, the Fe-doped NiOOH is widely deemed to be superior constituents for OER in an alkaline environment. However, the facile construction of robust Fe-doped NiOOH electrocatalysts is still a great challenge. Herein, we report the facile construction of Fe-doped NiOOH on Ni(OH)2 hierarchical nanosheet arrays grown on nickel foam (FeNi@NiA) as efficient OER electrocatalysts through a facile in-situ electrochemical activation of FeNi-based Prussian blue analogues (PBA) derived from Ni(OH)2. The resultant FeNi@NiA heterostructure shows high intrinsic activity for OER due to the modulation of the overall electronic energy state and the electrical conductivity. Importantly, the electrochemical measurement revealed that FeNi@NiA exhibits a low overpotential of 240 mV at 10 mA/cm2 with a small Tafel slope of 62 mV dec−1 in 1.0 M KOH, outperforming the commercial RuO2 electrocatalysts for OER.
Self-Healing Composites: A Path to Redefining Material Resilience—A Comprehensive Recent Review
Authors: Durão Maria Luísa , Nobre Luís , Mota Carlos , Bessa João , Cunha Fernando , Fangueiro Raúl
Published: September 2024

Polymeric composites are prone to undergoing damage, such as microcracks, during their operation, which can ultimately lead to catastrophic failure. To contradict such a problem, efforts have been carried out, by the scientific community, towards developing self-healing composites that, by mimicking biological systems, can autonomously and prematurely repair flaws, extending the durability and improving the security of materials. The present review explores the progress made in this area, focusing on extrinsic self-healing methods, as these can be employed to a variety of materials. Reservoir-based techniques, which resort to capsules, hollow fibers or microvascular networks, and thermoplastic-based ones are overviewed, prioritizing innovative approaches made in recent years. At last, promising practical applications for self-healing composites are highlighted and future challenges and opportunities are pointed out.
Experimental Study on Acoustic Emission Features and Energy Dissipation Properties during Rock Shear-Slip Process
Authors: Zhang Zhengnan , Liu Xiangxin , Zhao Kui , Liang Zhengzhao , Gong Bin , You Xun
Published: September 2024

The features of rock shear-slip fracturing are closely related to the stability of rock mass engineering. Granite, white sandstone, red sandstone, and yellow sandstone specimens were selected in this study. The loading phase of “shear failure > slow slip > fast slip” was set up to explore the correlation between fracture type, acoustic emission (AE) features, and energy dissipation during the rock fracturing process. The results show that there is a strong correlation between fracture type, energy dissipation, and AE features. The energy dissipation ratio of tension-shear (T-S) composite, shear, and tensile types is 10:100:1. The fracture types in the shear failure phase are mainly tensile and TS composite types. The differential mechanism of energy dissipation of different rocks during the shear-slip process is revealed from the physical property perspectives of mineral composition, particle size, and diagenetic mode. These results provide a necessary research basis for energy dissipation research in rock failure and offer an important scientific foundation for analyzing the fracture propagation problem in the shear-slip process. They also provide a research basis for further understanding the acoustic emission characteristics and crack type evolution during rock shear and slip processes, which helps to better understand the shear failure mechanism of natural joints and provides a reference for the identification of precursors of shear disasters in geotechnical engineering.
High-Temperature Mechanical–Conductive Behaviors of Proton-Conducting Ceramic Electrolytes in Solid Oxide Fuel Cells
Authors: Kang Shimeng , Yao Penghui , Pan Zehua , Jing Yuhang , Liu Siyu , Zhou Yexin , Wang Jingyi , Gao Yan , Sun Yi , Li Yongdan , Zhong Zheng
Published: September 2024

Proton-conducting solid oxide fuel cells (P-SOFCs) are widely studied for their lower working temperatures than oxygen-ion-conducting SOFCs (O-SOFCs). Due to the elevated preparation and operation temperatures varying from 500 °C to 1500 °C, high mechanical stresses can be developed in the electrolytes of SOFCs. The stresses will in turn impact the electrical conductivities, which is often omitted in current studies. In this work, the mechanical–conductive behaviors of Y-doped BaZrO3 (BZY) electrolytes for P-SOFCs under high temperatures are studied through molecular dynamics modeling. The Young’s moduli of BZY in fully hydrated and non-hydrated states are calculated with different Y-doping concentrations and at different temperatures. It is shown that Y doping, oxygen vacancies, and protonic point defects all lead to a decrease in the Young’s moduli of BZY at 773 K. The variations in the conductivities of BZY are then investigated by calculating the diffusion rates of protons in BZY at different triaxial, biaxial, and uniaxial strains from 673 K to 873 K. In all cases, the diffusion rate present a trend of first increasing and then decreasing from compression state to tension state. The variations in elementary affecting factors of proton diffusion, including hydroxide rotation, proton transfer, proton trapping, and proton distribution, are then analyzed in detail under different strains. It is concluded that the influences of strains on these factors collectively determine the changes in proton conductivity.
Roll-to-Roll SiOx Synthesis on Polyethylene Terephthalate Film by Atmospheric-Pressure Plasma-Assisted Chemical Vapor Deposition
Authors: Kusano Yukihiro , Bredgaard Kim , Pan Huifang , Bardenstein Alexander Leo
Published: September 2024

Silicon oxide (SiOx) coatings are attracting significant attention and are widely used in industrial applications. They can be prepared by plasma-assisted chemical vapor deposition (PACVD). PACVD at atmospheric pressure (AP-PACVD) is often employed to synthesize SiOx coatings, but it has generally not been scaled up to an industrially viable level. In the present work, a SiOx coating was continuously deposited onto a polyethylene terephthalate film using industrial-scale roll-to-roll type AP-PACVD. 1,1,3,3-Tetramethyldisiloxane (TMDSO) and tetraethoxysilane (TEOS) were selected as precursors. The elemental compositions and chemical structures of the SiOx coatings were characterized, and oxygen and water-vapor transmission rates were measured. The SiOx coating using TEOS exhibited better barrier properties than that using TMDSO, corresponding to the high oxygen content, high SiO2 content, and high siloxane network content in the SiOx coating.
Pick and Place Control of a 3-DOF Robot Manipulator Based on Image and Pattern Recognition
Authors: Kariuki Samuel , Wanjau Eric , Muchiri Ian , Muguro Joseph , Njeri Waweru , Sasaki Minoru
Published: September 2024

Board games like chess serve as an excellent testbed for human–robot interactions, where advancements can lead to broader human–robot cooperation systems. This paper presents a chess-playing robotic system to demonstrate controlled pick and place operations using a 3-DoF manipulator with image and speech recognition. The system identifies chessboard square coordinates through image processing and centroid detection before mapping them onto the physical board. User voice input is processed and transcribed into a string from which the system extracts the current and destination locations of a chess piece with a word error rate of 8.64%. Using an inverse-kinematics algorithm, the system calculates the joint angles needed to position the end effector at the desired coordinates actuating the robot. The developed system was evaluated experimentally on the 3-DoF manipulator with a voice command used to direct the robot movement in grasping a chess piece. Consideration was made involving both the own pieces as well as capturing the opponent’s pieces and moving the captured piece outside the board workspace.
The Effect of Support Misalignment on Vibration Characteristics of Aero-Engine Rotor Systems under Ultra-High Operating Speeds
Authors: Heng Xing , Zhang Haibiao , Wang Ailun , Zhang Wei
Published: September 2024

In order to ensure the vibration safety of rotor systems in the next generation of aero-engines and reduce the impact of misalignment faults, the effect of support misalignment on the vibration characteristics of rotor systems under ultra-high operating speeds is investigated in this paper. Firstly, an analytical excitation model of the rotor systems under ultra-high operating speeds is established, considering the impact of the support misalignment. Then, based on the model of the misaligned combined support system, the dynamic model of the flexible discontinuous rotor support system with the support misalignment is presented. Subsequently, based on the established model, the effects of support parameters and support misalignment amounts on the vibration characteristics of the rotor support system are analyzed. Finally, experimental validation of the research findings is conducted. The research result shows that the support misalignment increases the vibration response of the rotor, reduces the vibration reduction efficiency of the combined support system, and consequently decreases the vibration safety of the rotor support system.
The Dynamic Event-Based Non-Fragile H∞ State Estimation for Discrete Nonlinear Systems with Dynamical Bias and Fading Measurement
Authors: Luo Manman , Yang Baibin , Yan Zhaolei , Shen Yuwen , Hu Manfeng
Published: September 2024

The present study investigates non-fragile H∞ state estimation based on a dynamic event-triggered mechanism for a class of discrete time-varying nonlinear systems subject to dynamical bias and fading measurements. The dynamic deviation caused by unknown inputs is represented by a dynamic equation with bounded noise. Subsequently, the augmentation technique is employed and the dynamic event-triggered mechanism is introduced in the sensor-to-estimator channel to determine whether data should be transmitted or not, thereby conserving resources. Furthermore, an augmented state-dependent non-fragile state estimator is constructed considering gain perturbation of the estimator and fading measurements during network transmission. Sufficient conditions are provided based on Lyapunov stability and matrix analysis techniques to ensure exponential mean-square stability of the estimation error system while satisfying the H∞ disturbance fading level. The desired estimator gain matrix can be obtained by solving the linear matrix inequality (LMI). Finally, an example is presented to illustrate the effectiveness of the proposed method for designing estimators.
Machine Learning Prediction of Fuel Cell Remaining Life Enhanced by Variational Mode Decomposition and Improved Whale Optimization Algorithm
Authors: Huang Zerong , Zhang Daxing , Wang Xiangdong , Huang Xiaolong , Wang Chunsheng , Liao Liqing , Dong Yaolin , Hou Xiaoshuang , Cao Yuan , Zhou Xinyao
Published: September 2024

In predicting the remaining lifespan of Proton Exchange Membrane Fuel Cells (PEMFC), it is crucial to accurately capture the multi-scale variations in cell performance. This study employs Variational Mode Decomposition (VMD) to decompose performance data into intrinsic modes, elucidating critical multi-scale dynamics vital for understanding the complex degradation processes in fuel cells. In addition to VMD, this research utilizes an Improved Whale Optimization Algorithm (IWOA) to optimize a Back Propagation (BP) Neural Network. The IWOA focuses on precise adjustments of weights and biases, enabling the BP network to effectively interpret complex nonlinear relationships within the dataset. This optimization enhances the predictive model’s reliability and stability. Extensive experimental evaluations demonstrate that the integration of VMD, and the learning capabilities of the IWOA-optimized BP network significantly improves the model’s accuracy and stability across multiple predictions, thereby increasing the reliability of lifespan predictions for PEMFCs. This methodology offers a robust framework for extending the operational life and efficiency of fuel cells.
An Iteratively Reweighted Importance Kernel Bayesian Filtering Approach for High-Dimensional Data Processing
Authors: Liu Xin
Published: September 2024

This paper proposes an iteratively re-weighted importance kernel Bayes filter (IRe-KBF) method for handling high-dimensional or complex data in Bayesian filtering problems. This innovative approach incorporates importance weights and an iterative re-weighting scheme inspired by iteratively re-weighted Least Squares (IRLS) to enhance the robustness and accuracy of Bayesian inference. The proposed method does not require explicit specification of prior and likelihood distributions; instead, it learns the kernel mean representations from training data. Experimental results demonstrate the superior performance of this method over traditional KBF methods on high-dimensional datasets.
Nanoscale Extracellular Vesicle-Enabled Liquid Biopsy: Advances and Challenges for Lung Cancer Detection
Authors: Khan Adeel , Raza Faisal , He Nongyue
Published: September 2024

Lung cancer is responsible for the death of over a million people worldwide every year. With its high mortality rate and exponentially growing number of new cases, lung cancer is a major threat to public health. The high mortality and poor survival rates of lung cancer patients can be attributed to its stealth progression and late diagnosis. For a long time, intrusive tissue biopsy has been considered the gold standard for lung cancer diagnosis and subtyping; however, the intrinsic limitations of tissue biopsy cannot be overlooked. In addition to being invasive and costly, it also suffers from limitations in sensitivity and specificity, is not suitable for repeated sampling, provides restricted information about the tumor and its molecular landscape, and is inaccessible in several cases. To cope with this, advancements in diagnostic technologies, such as liquid biopsy, have shown great prospects. Liquid biopsy is an innovative non-invasive approach in which cancer-related components called biomarkers are detected in body fluids, such as blood, urine, saliva and others. It offers a less invasive alternative with the potential for applications such as routine screening, predicting treatment outcomes, evaluating treatment effectiveness, detecting residual disease, or disease recurrence. A large number of research articles have indicated extracellular vesicles (EVs) as ideal biomarkers for liquid biopsy. EVs are a heterogeneous collection of membranous nanoparticles with diverse sizes, contents, and surface markers. EVs play a critical role in pathophysiological states and have gained prominence as diagnostic and prognostic biomarkers for multiple diseases, including lung cancer. In this review, we provide a detailed overview of the potential of EV-based liquid biopsy for lung cancer. Moreover, it highlights the strengths and weaknesses of various contemporary techniques for EV isolation and analysis in addition to the challenges that need to be addressed to ensure the widespread clinical application of EV-based liquid biopsies for lung cancer. In summary, EV-based liquid biopsies present interesting opportunities for the development of novel diagnostic and prognostic platforms for lung cancer, one of the most abundant cancers responsible for millions of cancer-related deaths worldwide.
The Seven-State RF MEMS Miniaturized Broadband Reconfigurable Step Attenuator
Authors: Si Yuheng , Chen Siming , Fu Peifang , Yu Jian , Ma Binyi , Wu Qiannan , Li Mengwei
Published: September 2024

This paper presents a three-channel reconfigurable step attenuator based on radio frequency (RF) microelectromechanical system (MEMS) switches, in response to the current issues of high insertion loss and low attenuation accuracy of attenuators. The coplanar waveguide (CPW), cross-shaped power dividers, RF MEMS switches, and π-type attenuation resistor networks are designed as a basic unit of the attenuator. The attenuator implemented attenuation of 0~30 dB at 5 dB intervals in the frequency range of 1~25 GHz through two basic units. The results show that the insertion loss is less than 1.41 dB, the attenuation accuracy is better than 2.48 dB, and the geometric size is 2.4 mm × 4.0 mm × 0.7 mm. The attenuator can be applied to numerous fields such as radar, satellites, aerospace, electronic communication, and so on.
Diversity and Complexity of CTXΦ and Pre-CTXΦ Families in Vibrio cholerae from Seventh Pandemic
Authors: Li Xiaorui , Han Yu , Zhao Wenxuan , Xiao Yue , Huang Siyu , Li Zhenpeng , Fan Fenxia , Liang Weili , Kan Biao
Published: September 2024

CTXΦ is a lysogenic filamentous phage that carries the genes encoding cholera toxin (ctxAB), the main virulence factor of Vibrio cholerae. The toxigenic conversion of environmental V. cholerae strains through CTXΦ lysogenic infection is crucial for the emergence of new pathogenic clones. A special allelic form of CTXΦ, called pre-CTXΦ, is a precursor of CTXΦ and without ctxAB. Different members of the pre-CTXΦ and CTXΦ families are distinguished by the sequence of the transcriptional repressor-coding gene rstR. Multiple rstR alleles can coexist within a single strain, demonstrating the diverse structure and complex genomic integration patterns of CTXΦ/pre-CTXΦ prophage on the chromosome. Exploration of the diversity and co-integration patterns of CTXΦ/pre-CTXΦ prophages in V. cholerae can help to understand the evolution of this phage family. In this study, 21 V. cholerae strains, which were shown to carry the CTXΦ/pre-CTXΦ prophages as opposed to typical CTXETΦ-RS1 structure, were selected from approximately 1000 strains with diverse genomes. We identified two CTXΦ members and six pre-CTXΦ members with distinct rstR alleles, revealing complex chromosomal DNA integration patterns and arrangements of different prophages in these strains. Promoter activity assays showed that the transcriptional repressor RstR protected against CTXΦ superinfection by preventing the replication and integration of CTXΦ/pre-CTXΦ phages containing the same rstR allele, supporting the co-integration of the diverse CTXΦ/pre-CTXΦ members observed. The numbers and types of prophages and their co-integration arrangements in serogroup O139 strains were more complex than those in serogroup O1 strains. Also, these CTXΦ/pre-CTXΦ members were shown to present the bloom period of the CTXΦ/pre-CTXΦ family during wave 2 of the seventh cholera pandemic. Together, these analyses deepen our comprehension of the genetic variation of CTXΦ and pre-CTXΦ and provide insights into the evolution of the CTXΦ/pre-CTXΦ family in the seventh cholera pandemic.