Search Results (1,237)

In laser metal deposition (LMD), complex thermo-mechanical coupling and irregular layer morphology significantly affect residual stress distribution. However, most simulations rely on idealized geometries, limiting prediction accuracy. This study proposes a data-driven framework integrating in situ vision-based morphology reconstruction with thermo-mechanical simulation for high nitrogen steel (HNS). An improved DeepLabv3+ network is developed to extract deposition layer contours under strong illumination and spatter interference, achieving a mean intersection over union (mIoU) of 97.32% and an overall accuracy of 99.42%. The reconstructed morphology is incorporated into a finite element model to enable dynamic heat source tracking and realistic geometric representation. The proposed method demonstrates high morphology reconstruction accuracy, with all measurement errors controlled within 0.91%. The simulated temperature field agrees well with experimental measurements. Furthermore, the predicted residual stress distribution is consistent with X-ray diffraction (XRD) results under different laser power conditions. The results indicate that local surface morphology significantly influences stress concentration, with protrusion regions exhibiting stress peaks up to 989 MPa, markedly higher than those in concave regions. This study improves the accuracy of residual stress prediction in LMD by incorporating real morphology data and provides insight into the relationship between morphological features and stress evolution in additively manufactured HNS components. Full article

Circular RNAs (circRNAs) exhibit significant sex- and development stage-specific expression patterns in the gonads of various fish species, yet their functions and regulatory mechanisms in male reproductive development remain largely unexplored in crucian carp (Carassius auratus). In this study, we characterized the expression features and biological functions of circSPEF2, a circular RNA derived from the reproduction-related gene spef2. Our results showed that circSPEF2 expression was markedly elevated in mature testes and progressively upregulated during gonadal maturation. Functional studies suggested that circSPEF2 likely does not act through a ceRNA-dependent mechanism. Transcriptome sequencing following circSPEF2 overexpression identified 45 upregulated and 70 downregulated differentially expressed genes, with GO and KEGG enrichment analyses revealing significant alterations in multiple gonadal development-related genes and signaling pathways. Subsequent siRNA-mediated knockdown of circSPEF2, combined with qRT-PCR validation, confirmed that circSPEF2 positively regulates the expression of genes associated with cell maturation and differentiation, including prdm1a, lamc2, and slc25a27, while concurrently suppressing that of proliferation- and apoptosis-related genes such as wnt8b, cpeb3, and bcl2l11. Furthermore, RNA pull-down combined with mass spectrometry identified three candidate circSPEF2-binding proteins, namely, hnRNP A/B, SRSF2, and CFAP263. Collectively, these findings indicate that circSPEF2 plays an important role in male gonadal development in fish and provide new insights into the post-transcriptional regulatory mechanisms underlying vertebrate male reproduction. Full article

While CO₂ huff-n-puff (CO₂ HnP) is a promising technique for shale oil recovery, the characteristics and controlling factors of microscopically movable oil in lacustrine argillaceous-rich shales remain poorly understood. Shale samples from the Qingshankou Formation in the Songliao Basin were collected, and a series of experiments, including low-pressure N₂ adsorption, mercury injection porosimetry, and nuclear magnetic resonance, were conducted. High-pressure and high-temperature CO₂ HnP experiments were then conducted to investigate the effects of cycle number, soaking time and changes in pore structure on movable oil distribution. The shales exhibit multi-scale pores and lamellar fractures containing substantial residual oil (41.33–52.16% saturation). CO₂ HnP effectively mobilizes oil from macropores (50–1000 nm) and fractures (>1000 nm), with a limited effect in micro–mesopores (<50 nm). Three CO₂ HnP cycles were optimal for movable oil extraction. Extending the soaking time increased movable oil by ~4%, primarily from macropores and fractures (5.59–6.05%), with minimal improvement in smaller pores. A combination of CO₂ flooding followed by CO₂ HnP increased total movable oil by 4.83–7.26%, significantly enhancing recovery from micropores (7.26%) and macropores (9.21%). This study clarifies the pore size distribution and mobilization constraints of movable oil in argillaceous-rich shales. The integrated CO₂ flooding and HnP strategy proves to be highly effective, especially for movable oil in micro–mesopores. This study is the first to investigate pore-scale movable oil in lacustrine argillaceous-rich shales during CO₂ huff-n-puff under in situ reservoir conditions, and could provide critical insights for optimizing shale oil recovery in the Songliao Basin and similar lacustrine reservoirs. Full article

The internationalization of university research is driven by multiple, overlapping rationales that operate across institutional and individual dimensions and condition how international engagement becomes feasible in practice. This study examines how Honduran university faculty constructs and articulates the reasons for internationalizing their research activities; it identifies the discursive positions that emerge from these accounts. A qualitative–structural approach was used to analyze the discursive data produced in the group meetings convened through with an ad hoc structural sample. The analysis identified and graphically represented five discursive positions configured as a relational structure: (A) Professional Development, (B) Ethical–Political Commitment, (C) Financial Acquisition, (D) Academic Prestige, and (E) Sociocultural Engagement. Together, these positions capture distinct yet interrelated motivations by which faculty members pursue research internationalization. By mapping this relational configuration, the study contributes to the literature by showing how faculty rationales are combined and hierarchized in situated academic practice and provides empirically grounded insights for designing, planning, and managing strategies that align institutional priorities with the diversity of faculty rationales, thereby leveraging their tensions and complementarities to strengthen the effectiveness and sustainability of research internationalization within the university context. Full article

Background/Objectives: The Black Caribbean population of Honduras, also referred to locally as Negro Inglés, constitutes one of the country’s nine recognized indigenous and Afro-descendant peoples. Predominantly settled in the Bay Islands and sections of the Caribbean coast, this community traces its ancestry predominantly to West Africa and has remained culturally and linguistically distinct for more than three centuries. Despite its demographic and historical relevance, no population-specific short tandem repeat (STR) database has been established for this group. Methods: Allele frequencies for 23 autosomal STR loci were characterized in 100 unrelated Black Caribbean individuals from the department of Islas de la Bahía. DNA was extracted from blood on FTA cards and amplified with the PowerPlex Fusion 6C System (Promega Corporation). Statistical parameters were computed using Genepop v4.2, Arlequin v3.5 and GDA v1.0. Results: A total of 241 distinct alleles were detected across all 23 loci (mean 10.48 ± 3.85 alleles/locus). Expected heterozygosity ranged from 0.6541 (D13S317) to 0.9350 (SE33), with a mean of 0.8150 ± 0.0664—values consistent with a population of predominantly West African origin. No locus exhibited a significant departure from Hardy–Weinberg equilibrium after Bonferroni correction (α = 0.0022). The combined power of discrimination exceeded 99.9999% and the combined chance of exclusion surpassed 99.9999%. Conclusions: This first genetic characterization of the Honduran Black Caribbean population delivers an essential, population-specific reference dataset for forensic casework, paternity testing, and population genetics research. The data also deepen the understanding of Afro-descendant genetic diversity in Central America and constitute a critical step towards equitable forensic genetic services for all Honduran ethnic communities. Full article

Background/Objectives: Head and neck sarcomas account for 11% of all soft tissue and 9% of all bone sarcomas in the UK. Diagnostic delays are common, with non-specific symptoms and histological misdiagnosis reported in up to 42% of cases. This study aims to evaluate the association between presenting symptoms, symptom duration, and tumour size to inform a tailored HNS diagnostic strategy for early referral to a tertiary centre. Methods: We analysed a retrospective cohort of 425 adult and paediatric patients referred to the London Sarcoma Service between 2002 and 2025. Results: Our cohort analysis identified a median tumour size of 44.00 mm and symptom duration of 3 months. Although symptom duration did not predict tumour size (β = 0.63, p = 0.76), non-specific symptoms (swelling, pain, nasal/oral changes) were significantly associated with larger tumours (OR 1.96–3.66), alongside systemic symptoms (β = 22.90 mm, p = 0.044). Each 1 mm increase in tumour size was also associated with a 2.60% increased chance of a higher-grade sarcoma (OR = 1.03 per mm, p < 0.001). Conclusions: To our knowledge, this is the largest cohort study to characterise diagnostic patterns in HNS. Our findings reveal three critical insights: 1. Current size-based referral thresholds are inadequate. 2. Non-specific symptoms, such as nasal or oral symptoms, are frequently overlooked. 3. The anatomical complexity of the HN region demands early tailored diagnostic strategies. We propose a hypothesis-generating ‘1–2–1’ framework to support earlier clinical suspicion, which requires prospective validation. Full article

Entrepreneurship education has been promoted as a pathway for strengthening entrepreneurial orientation among university students; however, uncertainty remains regarding the mechanisms through which it influences entrepreneurial intention, particularly in emerging economies. This study examines whether entrepreneurship education influences the entrepreneurial intention of university students in Honduras indirectly through entrepreneurial self-efficacy and entrepreneurial motivation. A quantitative, cross-sectional, and explanatory study was conducted with a sample of 431 university students. Data were collected using a structured 56-item questionnaire with a seven-point Likert scale. The analysis was carried out through confirmatory factor analysis and structural equation modeling using the WLSMV estimator. The results show that entrepreneurship education positively influences all dimensions of entrepreneurial self-efficacy and entrepreneurial motivation included in the model. Personal attitude emerged as the strongest predictor of entrepreneurial intention, followed by subjective norms and specific dimensions of self-efficacy related to business planning and management and entrepreneurial leadership. In contrast, the innovation and problem-solving dimension did not show a significant direct effect on entrepreneurial intention, while perceived behavioral control showed a marginal effect. The parsimonious model explained 75.9% of the variance in entrepreneurial intention. Overall, the findings suggest that entrepreneurship education exerts its influence primarily through indirect pathways by strengthening capability beliefs and motivational appraisals that are proximal to action. Full article

Hypertensive nephropathy (HN) is a leading cause of chronic kidney disease and end-stage renal disease worldwide and results from the long-term effects of hypertension on renal structure and function. The pathogenesis of HN is complex and involves haemodynamic disturbances, renal vascular injury, oxidative stress, chronic inflammation, and progressive interstitial fibrosis. In recent years, increasing attention has focused on the role of non-coding RNAs (ncRNAs)—including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs)—as key regulators of gene expression involved in these processes. This review summarises the current understanding of the molecular mechanisms underlying HN, with particular emphasis on the roles of oxidative stress, activation of the renin–angiotensin–aldosterone system, transforming growth factor beta signalling, and inflammatory and fibrogenic pathways. The contribution of dysregulated ncRNAs to endothelial dysfunction, inflammatory responses, apoptosis, angiogenesis, and renal remodelling and fibrosis is also discussed. Particular attention is given to miRNAs and lncRNAs as mediators of disease progression and potential biomarkers, as well as to the emerging role of circRNAs in hypertensive kidney injury, including their involvement in the regulation of redox balance and intercellular communication. Collectively, available evidence indicates that ncRNAs represent a critical link between haemodynamic stimuli and persistent molecular alterations in renal tissue, highlighting their potential as diagnostic markers and therapeutic targets in HN. Full article

Yellow fever (YF) remains a re-emerging vector-borne zoonotic disease in tropical regions of the Americas despite the availability of an effective vaccine. In South America, the virus is maintained through a jungle transmission cycle involving Haemagogus and Sabethes mosquitoes and non-human primates (NHPs), which act as amplifying hosts and key epidemiological sentinels. This narrative review examines the current status of YF epizootics in South America, with a focus on the role of NHPs in viral circulation, early detection, and spillover risk to human populations. We synthesize recent evidence on epizootic patterns across endemic countries, the differential susceptibility of neotropical primates, and the ecological and environmental drivers influencing transmission, including deforestation, habitat fragmentation, and human encroachment into forested areas. In addition, we analyze current surveillance strategies, including wildlife monitoring, entomological and genomic surveillance, and their integration within a One Health framework. This review highlights that YF epizootics are expanding geographically and are closely linked to environmental change and human–ecosystem interactions. Strengthening integrated, multidisciplinary surveillance systems is essential to improve early detection, guide vaccination strategies, and prevent human outbreaks. These findings underscore the critical importance of operationalizing the One Health approach to enhance preparedness and response to YF in South America. Full article

Avian orthoavulavirus 1 (AOaV-1), commonly known as Newcastle disease virus (NDV), despite widespread vaccination, remains a significant threat to domestic chickens (Gallus gallus domesticus). Currently available live-attenuated NDV vaccines are derived from genotypes I and II lentogenic strains, whereas genetically divergent velogenic strains predominantly caused recent NDV outbreaks. This study examined the extent of genotypic divergence between NDV vaccine strains and field strains using phylogenetic and multivariate analyses of two major antigenic and virulence-associated genes: fusion (F) and haemagglutinin-neuraminidase (HN). A total of 121 full-length NDV-F and 81 NDV-HN gene sequences, representing reported NDV genotypes, were downloaded from GenBank and analysed using maximum-likelihood (ML) phylogenetic trees and principal coordinates analysis (PCoA). The phylogeny revealed genotype-specific clustering for both genes, consistent with current NDV classification. NDV vaccine strains belonging to genotypes I and II formed distinct clades, segregated from the majority of NDV field strains, including velogenic or virulent NDV genotypes. The principal coordinates analysis of both genes further confirmed the phylogenetic clustering of NDV genotypes, indicating increased genomic heterogeneity. These findings suggest genetic segregation of divergent velogenic or virulent genotypes from lentogenic NDV vaccines, requiring biological experiments for determining their efficacy against field strains. This study highlights the importance of molecular surveillance of NDV to monitor its genomic diversity, which is crucial for developing strategies to combat NDV outbreaks in domestic chickens. This study provides an updated, NDV-glycoprotein-gene-based comparative analysis across reported NDV genotypes using phylogenetic and multivariate approaches. Full article

Neurodegenerative diseases arise when normally functional aggregation-prone proteins transition into stable cross-β amyloid fibrils. Although these fibrils share a conserved architecture, the pathways that lead to fibrillation vary across proteins and cellular environments. Liquid–liquid phase separation is now recognized as a central organizer of intracellular biochemistry that modulates protein aggregation. Physiological condensation can buffer aggregation by maintaining macromolecular solubility and providing partner interactions that compete against pathological protein–protein interactions. However, condensates can transform and age into gel-like states that can favor the emergence of β-rich oligomers and solid-state fibrils. Across six disease-linked proteins that include Tau, α-synuclein, amyloid-β, TDP-43, FUS, and hnRNPA1, we compare how sequence-encoded interaction motifs, cellular cofactors, and interfacial microenvironments shape the balance between physiological condensates and pathological amyloids. Here, we highlight the unifying drivers of aggregation and intervention points that preserve native function while limiting toxic amyloid formation. Full article

Background: The genus Brucella has expanded considerably in the 21st century. With the advent of advanced phylogenetic analyses, a close genetic relationship between Brucella and Ochrobactrum has been identified, leading to reclassification of Ochrobactrum species within the genus Brucella. Among these, Brucella anthropi (formerly Ochrobactrum anthropi) is increasingly recognized as a rare cause of invasive human infection. We report a clinically significant case of B. anthropi infective endocarditis and review the available literature. Methods: We report a case of B. anthropi infective endocarditis and conducted a narrative review of the English-language medical literature through 2025. Cases were analyzed for demographics, clinical presentation, antimicrobial susceptibility, and outcomes. Results: A 75-year-old man with a prosthetic aortic valve and prior endocarditis presented with fever of unknown origin, weight loss, and prior transient ischemic attacks. Blood cultures grew B. anthropi after prolonged incubation. Transesophageal echocardiography demonstrated vegetations involving both the aortic and tricuspid valves, and the patient required targeted combination antimicrobial therapy due to persistent bacteremia. Seven additional cases of B. anthropi infective endocarditis were identified on review of the literature. Most patients had underlying valvular disease or prosthetic material. Reported lethality approached 25%. Antimicrobial susceptibility patterns were variable, underscoring the importance of targeted individualized therapy. Conclusion: Consistent with other Gram-negative bacilli, B. anthropi is a rare but established cause of acute bacterial endocarditis. Despite its rarity, it may represent an under-recognized cause of invasive disease. This case highlights the importance of prolonged culture incubation, careful microbiologic interpretation, and susceptibility-guided therapy. Full article

Background: The Pech ethnic group, comprising approximately 6024 individuals in northeastern Honduras, represents one of the country’s smallest indigenous communities with a rich cultural heritage extending to pre-Columbian times. Despite their historical significance, no population genetic studies have been conducted on this group, and population-specific databases are essential for accurate forensic applications. Methods: Allele frequencies for 23 autosomal short tandem repeat (STR) loci were determined in 100 unrelated Pech individuals (58 females, 42 males) from communities in the departments of Olancho, Colón, and Gracias a Dios. DNA was extracted from blood samples collected on FTA cards and amplified using the PowerPlex Fusion 6C System. Statistical parameters were calculated using Genepop v4.2 and Arlequin v5.3.2.2. Results: All loci exhibited substantial polymorphism. No statistically significant deviations from Hardy–Weinberg equilibrium were detected after Bonferroni correction (α = 0.0022). Expected heterozygosity ranged from 0.4033 (TH01) to 0.8563 (FGA). The combined power of discrimination exceeded 99.9999%, and the combined chance of exclusion was 99.9999%. Conclusions: This study presents the first genetic characterization of the Pech population, providing essential reference data for forensic identification, paternity testing, and population genetics research. The dataset fills a critical gap in the Honduran forensic genetic infrastructure and contributes to understanding indigenous Central American genetic diversity, enabling accurate forensic analyses for individuals of Pech ancestry in compliance with CODIS and ESS standards. Full article

Background: The Garifunas are a distinctive Afro-indigenous community of Honduras, originating from the historical admixture of Island Carib, Arawak, and West African peoples in the seventeenth-century Caribbean. With an estimated 43,111 individuals residing primarily along the northern Atlantic coast. Their dual ancestral composition yields a genetic profile that differs meaningfully from those of other Honduran reference populations, consistent with pairwise FST comparisons with previously published Lenca and Tawahka datasets generated on the identical platform; yet no population-specific short tandem repeat (STR) reference dataset had previously been established. Methods: We genotyped 23 autosomal STR loci using the PowerPlex Fusion 6C System (Promega Corporation) in 100 unrelated Garifuna individuals (70 females, 30 males) sampled from three coastal settlements in the department of Atlántida: Triunfo de la Cruz, Ensenada, and Corozal. DNA was extracted from blood collected on FTA cards, and statistical parameters were computed using Genepop v4.2 and Arlequin v5.3.2.2. Results: A total of 217 distinct alleles were identified, with 5 to 19 alleles per locus (mean 9.43 ± 3.54). Expected heterozygosity (He) ranged from 0.6392 (D13S317) to 0.9010 (SE33), with a population mean of 0.7893. No locus deviated from Hardy–Weinberg equilibrium after Bonferroni correction (α = 0.0022). The combined random match probability was approximately 1.9 × 10⁻²⁶, and the combined chance of exclusion reached 99.99999993%. Conclusions: This study provides the first Honduran Garifuna population-specific autosomal STR reference database for precise forensic likelihood ratio estimates, kinship assessments, and population genetic studies. The Garifuna’s high diversity—consistent with their West African and Amerindian ancestry—indicates the risk of systematic bias when non-specific databases are used. Full article

Yellow fever remains a major public health threat in endemic and re-emerging regions of Africa and South America, with recent outbreaks highlighting persistent gaps in prevention and surveillance. Pregnant women represent a particularly vulnerable population, yet the epidemiology, clinical impact, and preventive strategies for yellow fever in pregnancy are insufficiently characterized. Physiological and immunological changes during gestation may influence host responses to infection; however, current evidence does not demonstrate increased susceptibility to or severity of yellow fever during pregnancy. Adverse materno-fetal outcomes, including miscarriage, stillbirth, preterm birth, and, in rare cases, perinatal transmission, have been reported but remain poorly characterized. Diagnostic challenges, overlapping clinical presentations with other arboviral and hepatic diseases, and limited access to specialized care further complicate clinical management in many endemic settings. This perspective provides a comprehensive overview of yellow fever in pregnancy during the 2024–2026 outbreak in the Americas, including a risk-stratification framework for prevention. We summarize current evidence on epidemiology, pathophysiology, diagnosis, and supportive care, and examine prevention strategies with particular emphasis on vaccination. Accumulated observational evidence and substantial real-world experience have not demonstrated an increased risk of serious adverse events and generally support the effectiveness of yellow fever vaccination during pregnancy when administered with appropriate clinical judgment. In high-risk settings, the benefits of maternal immunization clearly outweigh theoretical concerns, supporting a flexible, risk-based approach, despite relatively limited evidence. We also discuss national and international policies, post-pregnancy booster recommendations, and the importance of integrating vaccination assessment into antenatal care. Finally, we highlight critical knowledge gaps and research priorities, including the need for prospective registries and strengthened pharmacovigilance. Coordinated clinical and public health strategies are essential to protect maternal and neonatal health and to reduce the burden of yellow fever in endemic and re-emerging settings. Full article