Abstract: Wastewater-based epidemiology (WBE) was applied to monitor human-pathogenic respiratory viruses, including SARS-CoV-2, in the four largest Bulgarian cities during the summer and autumn of 2024. Starting from 1 liter wastewater samples, concentra-tion of the virus fraction with PEG 8000/NaCl, extraction and purification of DNA/RNA were applied. Detection of SARS-CoV-2, FluA/B, RSV and HCoV229E was performed with TaqMan qPCR. A total of 42 samples were processed over a 7-month period. Two summer peaks of SARS-CoV-2 were detected in the capital Sofia, in July and September 2024. With some differences, a similar result was observed in Plovdiv and Burgas. The concentration of SARS-CoV-2 in wastewater decreased significantly in November and December. Other respiratory viruses started to be detectable only at the beginning of October. The results of this study show an unusual summer peak of SARS-CoV-2 in wastewater from large cities, followed by a significant decrease of vi-rus concentrations in the fall. The established trend correlates with the statistics of COVID-19 incidence in Bulgaria.

Abstract: Generative Adversarial Networks (GANs) have demonstrated remarkable capabilities for synthesizing photorealistic textures, yet deploying conditional GANs (cGANs) in industrial settings faces two barriers: the prohibitive cost of annotating proprietary data and the uncertain alignment between automated metrics and human perception. This study addresses both challenges for marble texture synthesis. We adapt an unsupervised segmentation pipeline combining Simple Linear Iterative Clustering (SLIC) superpixels, Gaussian Mixture Models (GMMs), and Graph Cut optimization to extract vein structures from 289 industrial scans without manual annotation. We then benchmark four cGAN architectures, a baseline cGAN, Pix2Pix, BicycleGAN, and GauGAN, using a dual-evaluation protocol contrasting automated assessment via pixel-based metrics, structural metrics, statistical metrics, and learned distributional metrics with human-centered assessment. Results reveal a significant metric–perception discrepancy: Pix2Pix achieved the best FID yet received the lowest human ratings due to checkerboard artifacts, whereas GauGAN produced textures statistically indistinguishable from real marble (Visual Turing Pass Rate, VTPR: 0.533; Mean Opinion Score on Marble Authenticity, MOS-MA: 2.89) despite inferior FID (87.3). These findings establish three contributions: (1) an unsupervised annotation-free segmentation pipeline, (2) empirical evidence that automated metrics alone are insufficient for architecture selection, and (3) a dual-evaluation framework validating human-in-the-loop assessment as essential for industrial deployment.

Abstract: Vehicle–infrastructure cooperative perception (VICP) overcomes the sensing limitations and field-of-view constraints of single-vehicle intelligence by integrating multi-source information from onboard and roadside sensors. However, in complex urban environments, system robustness—particularly regarding blind-spot coverage and feature representation—is severely compromised by occlusion (static and dynamic) and distance-induced point cloud sparsity. To address these challenges, this paper proposes a 3D object detection framework incorporating point cloud feature enhancement and spatial adaptive fusion. First, to mitigate feature degradation under sparse and occluded conditions, a Redefined-SENet (R-SENet) attention module is embedded into the feature encoding stage. This module employs a dual-dimensional squeeze-and-excitation mechanism—across pillars and intra-pillar points—to adaptively recalibrate key geometric features. Concurrently, a Feature Pyramid Backbone Network (FPB-Net) is constructed to enhance unified target modeling across varying distances via multi-scale extraction and cross-layer aggregation. Second, a Spatial Adaptive Feature Fusion (SAFF) module is introduced to resolve feature heterogeneity and spatial misalignment. By explicitly encoding feature origins and leveraging spatial attention, SAFF enables dynamic weighting and complementary fusion of fine-grained vehicle-side features and global roadside semantics. Experiments on the DAIR-V2X benchmark and a custom dataset demonstrate that the proposed method outperforms state-of-the-art approaches, achieving Average Precision (AP) scores of 0.762 and 0.694 at IoU 0.5, and 0.617 and 0.563 at IoU 0.7, respectively. Furthermore, the inference speed satisfies real-time requirements, validating the method’s effectiveness and potential for engineering deployment.

Abstract: We prove that every even integer 2N ≥ 8 is the sum of two distinct primes. This variant of the classical Goldbach conjecture is established through three components: (1) a novel geometric equivalence reformulating the problem in terms of nested squares with semiprime areas, (2) a theoretical proof for all N ≥ 3275 using Dusart’s refinement on prime distribution, and (3) direct computational verification for 4 ≤ N ≤ 3274. The geometric framework reveals that the conjecture is equivalent to finding, for each N ≥ 4, an integer M ∈ [1, N − 3] such that the L-shaped region N2 − M2 between nested squares has area P · Q where P = N − M and Q = N + M are both prime. We define DN = {(Q − P)/2 | 2 < P < N < Q < 2N, both prime} to be the set of achievable half-differences from straddling prime pairs. The conjecture becomes equivalent to proving that DN ∩ {N − p | 3 ≤ p < N, p prime} ̸= ∅ for all N ≥ 4. Our gap function G(N) = log²(2N) − ((N − 3) − |DN|) measures the margin by which this condition holds. Computational analysis for N ∈ [4, 2¹⁴] reveals that G(N) > 0 universally, with minima strictly increasing across dyadic intervals. For N ≥ 3275, we prove theoretically that G(N) > 0 by showing that Dusart’s prime distribution theorem guarantees |DN| > (N − 3) − log²(2N). The pigeonhole principle then ensures existence of valid Goldbach partitions: since there are π(N −1)−1 > log²(2N) candidate primes P < N, and fewer than log²(2N) “bad” M-values, at least one candidate yields both P and Q = 2N − P prime. This completes the proof of the distinct-prime Goldbach variant and demonstrates the power of geometric reformulation combined with modern analytic number theory.

Abstract: Storage tanks are critical infrastructure in industries such as oil and gas, chemicals, and water treatment. Deformation poses serious risks, including catastrophic failures, environmental pollution, and economic losses. Current risk assessment methods often lack a structured, multi-criteria approach that integrates quantitative data with expert judgment, leading to potential omissions or subjective biases. A robust framework for predicting deformation risk is essential for proactive maintenance and safety management. This research proposes the development and application of an integrated multi-criteria decision-making (MCDM) methodology that combines the Analytic Hierarchy Process (AHP), the Preference Ranking Method for Enriching Evaluations (PROMETHEE), and the Geometric Analysis for Interactive Assistance (GAIA). The main focus is on establishing a rigorous, systematic, and defensible framework for selecting criteria specific to predicting the risk of storage tank deformation. The effectiveness of the AHP-PROMETHEE/GAIA method critically depends on identifying the most relevant, measurable, non-redundant, and comprehensive set of criteria that affect the risk of deformation. Poorly selected criteria will compromise the entire predictive model. This proposal directly addresses this critical gap.

Abstract: Pertussis is a highly contagious acute respiratory infection caused by Bordetella pertussis (B. pertussis), an exclusively human pathogen that remains a significant global public health concern despite widespread vaccination. Cyclical resurgences continue to occur, particularly in highly immunized populations, largely driven by waning immunity following acellular pertussis vaccination and persistent asymptomatic transmission among adolescents and adults. The pathogenesis of B. pertussis infection is mediated by a coordinated repertoire of adhesins and toxins that enable efficient colonization of the respiratory epithelium, disruption of mucociliary clearance, and profound modulation of host immune responses. Key virulence factors include pertussis toxin, adenylate cyclase toxin, and tracheal cytotoxin, which together impair innate immune defenses, alter leukocyte trafficking, suppress phagocytic function, and induce epithelial injury. While antibody-mediated immunity limits disease severity, it is insufficient to prevent colonization and onward transmission, underscoring the critical role of cell-mediated immunity. Protective clearance of infection is strongly associated with T helper 1 and T helper 17 immune responses, mucosal immunoglobulin A production, and the establishment of airway tissue-resident memory T cells—immune components that are suboptimally induced by current acellular vaccines. Advances in controlled human infection models have provided direct evidence that existing vaccines fail to prevent nasopharyngeal carriage, accelerating the development of next-generation vaccine strategies. These approaches aim to restore infection-like immune programming through mucosal delivery, enhanced innate immune activation, and broader antigenic presentation. Understanding the immune pathogenesis of B. pertussis infection provides a critical framework for redesigning vaccines capable of achieving durable, transmission-blocking immunity.

Abstract: Background: Food bank users experience food insecurity, which is a social determinant of health associated with poorer physical and mental outcomes. However, there is little evidence in Spain regarding the health-related quality of life (HRQoL) of food bank users. Objectives: To assess the HRQoL of users of the Navarra Food Bank (BAN) by identifying the associated factors and comparing it with the general population. Methods: Cross-sectional study of heads of families using the BAN. Simple random sample of 350 from a population of 2,749 families (p and q 0.5). We evaluated HRQoL using the EQ-5D-5L scale via telephone survey. We analyzed scores on the utility index (EQ-5D-5L Index) and the visual analog scale (VAS), as well as the distribution of problems related to mobility, personal care, daily activities, pain/discomfort, and anxiety/depression. To enhance interpretability and avoid the influence of arbitrary thresholds or extreme values, the VAS and EQ-5D-5L Index variables were dichotomized into higher and lower health-related quality of life (HRQoL) groups using a data-driven K-means cluster analysis. Subsequently, binary logistic regression was applied to identify factors associated with the higher HRQoL group, with age, sex, socioeconomic variables, and EQ-5D-5L dimensions included as independent variables. Odds ratios with 95% CI were calculated. Results: The VAS was 73.56 (71.62-75.50) compared to 88.1 in Navarra. The prevalence of problems with mobility, self-care, daily activities, pain/discomfort, and anxiety/depression was higher in all cases than in Navarra: 25.5% vs. 13.0%; 8.7% vs. 5.3%; 19.7% vs. 8.0%; 55.7% vs. 35.7%; and 62.9% vs. 17.3% (all p < 0.001). Sociodemographic variables (age, sex, education, and employment) showed no significant association with HRQoL clusters (p > 0.05). Conversely, controlling for age and sex, belonging to the group with the highest VAS was associated with a lower prevalence of problems: Mobility OR= 3.91 (95% CI: 1.84-8.30); Daily Activities OR= 2.98 (95% CI: 1.16-7.65); Pain/Discomfort OR=3.36 (95% CI: 1.64-6.89); and Anxiety/Depression OR= 2.84 (95% CI: 1.41-5.73). Belonging to the group with the highest EQ-5D-5L Index was not significantly associated with Anxiety/Depression (OR = 1.62; 95% CI: 0.73–3.56), whereas the remaining dimensions showed similar significant associations. Conclusions: Users of the Navarra Food Bank have a significantly worse HRQoL than the general population, primarily associated with a high prevalence of mental health challenges and pain. These findings highlight that food banks are critical touchpoints for the early detection of health vulnerabilities, necessitating a shift from purely nutritional aid toward integrated social and health support models.

Abstract: Ovarian cancer (OC) remains the deadliest gynecological malignancy, with aged tumor microenvironments linked to poorer outcomes. Our prior work identified reduced levels of free fatty acids (FFAs) within tumor-surrounding adipose tissue of aged OC xenograft rats compared to younger counterparts. In this study, we investigated the therapeutic potential of one such FFA, punicic acid (PunA). We evaluated PunA’s effects on OC and normal cell viability and compared its activity with that of its structural isomer, α-eleostearic acid (α-ESA). Both compounds decreased OC cell viability; however, α-ESA was cytotoxic to normal cells, whereas PunA selectively impaired OC cell viability while sparing normal cells. Additionally, PunA enhanced cisplatin efficacy, demonstrating its potential for use in combination therapy to reduce cisplatin dosage and toxicity without compromising antitumor activity. Mechanistically, PunA induced ferroptosis in OC cells while sparing normal cells by differently modulating lipid peroxidation, fatty acid oxidation, and mitochondrial function. Transcriptomic profiling further revealed broad gene expression and pathway reprogramming in PunA-treated OC and normal cells. In a preliminary C57BL/6J-ID8 OC mouse model, PunA suppressed tumor growth. Collectively, these findings identify PunA as a promising therapeutic candidate for OC, acting through ferroptosis and mitochondrial dysfunction, and enhancing cisplatin efficacy while sparing normal cells.

Abstract: This study presents a comprehensive numerical and experimental investigation into the influence of punch shaft geometry on punching force and tool durability in the cold forming of S500MC steel sheets using an AISI D2 punch. Finite element analyses were conducted to evaluate the effects of varying punch shaft diameters on stress distribution, deformation behavior, and resultant punching forces. Experimental validation was performed through controlled punching tests, measuring force responses and assessing tool wear. The results demonstrate that optimizing the punch shaft diameter reduces the maximum punching force and minimizes stress concentrations, thereby enhancing tool life. Specifically, larger punch shaft diameters contribute to more uniform stress distribution and decreased risk of premature tool failure. These findings provide valuable insights for tooling design in high-strength steel sheet forming processes, enabling improved efficiency and cost-effectiveness in manufacturing operations.

Abstract: Semi-supervised text classification (SSTC) faces challenges in pseudo-label quality and robustness, particularly with limited labeled data and imbalanced class distributions. To address these, we propose DynaMatch, a novel framework for adaptive SSTC that integrates Dynamic Self-Ensemble Learning (DSEL), Adaptive Confidence Scoring (ACDM), and Historical Bias Correction. DynaMatch leverages DSEL for robust predictions from instantaneous model states. ACDM then refines pseudo-labeling through self-ensemble diversity evaluation, dynamic threshold adjustment, and historical bias correction to identify valuable samples and mitigate class imbalance. Evaluated on the Unified Semi-supervised Benchmark (USB), including long-tailed imbalanced datasets, DynaMatch consistently outperforms state-of-the-art baselines. It achieves superior performance, with approximately 0.5% to 1.0% F1-score improvement, especially excelling in scenarios with scarce labeled data and severe class imbalance. An ablation study confirms the synergistic contributions of each component, reinforcing DynaMatch's efficacy and practical utility.

Abstract: Violence against children constitutes a global public health emergency, necessitating innovative prevention strategies within the school environment. While the benefits of visual arts on socio-emotional development are well-documented, their specific impact on preventing interpersonal violence remains under-synthesized. This critical narrative review analyzes existing literature (2000–2025) through a corpus of 14 empirical studies (exclusive visual arts interventions and multimodal programs) conducted with children aged 5 to 12. The results reveal a dichotomy: while art-centered interventions demonstrate robust effects on emotional regulation and anger reduction (protective factors), evidence for a direct reduction in violent behaviors primarily stems from large-scale multimodal programs. Although promising as a lever for universal prevention and the facilitation of disclosure, visual arts require further randomized controlled trials to validate their direct behavioral efficacy. This review proposes a conceptual framework for integrating these practices into child protection policies.

Abstract: Phenazine derivatives are attractive organic chromophores due to their redox activity and photophysical properties, yet their application in photocatalytic hydrogenation reactions remains underexplored. In this work, a homogeneous phenazine-based photocatalytic system was developed and applied to the visible-light-driven hydrogenation of nitro compounds under mild conditions. The photocatalysts’ activity was evaluated using nitrobenzene as a model substrate in the presence of triethanolamine as a sacrificial hydrogen and electron donor. Reaction parameters including photocatalyst structure, solvent, hydrogen source, irradiation wavelength, and catalyst loading were systematically investigated. Under optimized conditions, nitrobenzene was converted to aniline with yields of up to 81% after 12 h of irradiation at ambient temperature. Kinetic studies revealed that prolonged irradiation does not enhance conversion and can lead to decreased yields due to the instability and reconversion of azo-type intermediates. Substrate scope investigations demonstrated higher reductive efficiency for nitroarenes bearing electron-withdrawing substituents, whereas aliphatic nitro compounds were only partially reduced, often yielding oxime or N–OH intermediates. UV–Vis, fluorescence, and EPR spectroscopy provided mechanistic insight and confirmed the involvement of radical species generated upon light irradiation. Overall, this study establishes phenazine-based photocatalysts as effective metal-free systems for the hydrogenation of nitroarenes under visible light and mild reaction conditions.

Abstract: Severe post-traumatic ankle osteoarthritis in patients with ipsilateral knee arthrodesis represents a rare and challenging scenario due to altered biomechanics and postoperative rehabilitation demands. We report on two cases, aged 55 and 69 years, both with a long-standing knee ar-throdesis, treated with total ankle replacement through a lateral transfibular approach. In-traoperative alignment required careful correction given the fixed knee. Rehabilitation was tai-lored to gait re-education without knee flexion. At 36 months, both patients achieved pain relief, improved ankle motion, stable implants, and functional gait, supporting this approach as a viable option.

Abstract: This paper investigates cylindrical sphere packings, that is, patterns of uniform spheres with mutually disjoint interiors which are all tangent to a common cylinder. The key unifying themes are existence and uniqueness of hexagonal packings, in which each sphere is tangent to six others. Constructions are both intuitive and subtle, but result in the complete characterization in term of integer parameter pairs $(m,n)$. Interesting questions in rigidity and density are encountered. Density questions arise because the packings, being of equal diameter, lie within the space between inner and outer cylinders. This density problem hoovers between the 2D and 3D sphere packing cases, and though it is not solved here, it is conjectured that the hexagonal packings are densest for the countable number of cylinders which support them. Other geometric objects are along for the ride, including equilateral triangles and the packings' dual graphs, which are associated with patterns of carbon atoms forming buckytubes. Interesting structural rigidity questions also arise.

Abstract: Background: The aim of this study was to evaluate the clinical performance of an in-house qualitative CMV real-time PCR assay for the detection of cytomegalovirus (CMV) DNA in various non-plasma clinical sample types, in comparison with a commercial ref-erence method. Methods: In this prospective comparative study, 186 clinical sam-ples—including bronchoalveolar lavage fluid (BALF), stool, urine, colonoscopic biopsy, amniotic fluid, and intraocular fluid—were analyzed. A total of 166 samples with valid results from both test systems were included in the inter-method comparison. CMV DNA was detected using an in-house qualitative PCR assay in parallel with the reference method (artus® CMV QS-RGQ kit). Clinical performance was assessed using positive percent agreement (PPA), negative percent agreement (NPA), overall percent agreement (OPA), Cohen’s kappa coefficient (κ), and predictive values, in accordance with the CLSI EP12-A2 guideline for qualitative diagnostic tests. Results: When all clinical samples were evaluated collectively, good overall agreement was observed between the developed test and the reference method (κ = 0.66). High PPA, NPA, and kappa values were obtained for stool, urine, and invasive samples. In BALF samples, inter-method agreement was mod-erate, and the high NPV supported clinical exclusion of CMV infection. Predictive values varied according to the CMV DNA positivity rate of the analyzed sample groups. Conclusions: The laboratory-developed qualitative CMV PCR assay showed good inter-method agreement with a commercial reference method and appears suitable for qualitative CMV detection in non-plasma clinical specimens under routine laboratory conditions. The findings reflect comparative performance rather than gold-standard-based diagnostic accuracy or viral load quantification.

Abstract: Cerebral palsy (CP) is the most common form of motor disability in childhood, caused by nonprogressive brain damage occurring in fetal life or infancy. Although the current therapies mainly consist of symptomatic management using physical therapy, medications, and surgery, there is no cure. The proposed study will be the first to use a novel therapy involving the use of the axolotl's neural tissue for transplantation into the damaged areas of the motor cortex of patients suffering from cerebral palsy. The axolotl, whose scientific name is Ambystoma mexicanum, has the unique ability to regenerate its brain and neural tissues, including the variety of cells, the complexity, and the functional circuits. This paper will provide a thorough analysis of the proposed study, including the rationale, proposed procedure, challenges, and proposed research pathway. Although there seem to be many challenges, including the difference in immune systems, the advancements that have been made recently in the field of tissue engineering, immunosuppression, and the understanding of the axolotls' regenerative ability make it imperative to pursue this novel therapy. The ultimate goal of this research is to provide sufficient evidence to be able to submit a research proposal to research review and ethic boards to enable the conduct of the research.

Abstract: Management of ventricular tachycardia (VT) requires an integrated approach combining invasive therapy and cardiac imaging. This article reviews the principal imaging modalities and their integration with electroanatomical mapping systems to plan and guide procedures and to assess the success of VT ablation during follow-up. The central role of imaging in optimizing the efficacy and safety of VT ablation is emphasized. Studies demonstrating that imaging-supported workflows can improve substrate localization, reduce procedural times and radiation exposure, and lower recurrence rates are highlighted. Current limitations and future challenges are also discussed.

Abstract: We present a causal, falsifiable law of observer-indexed entropy retrieval dynamics whose growth rate of retrievable entropy is proportional to the remaining entropy gap, modulated by a hyperbolic-tangent regulator that switches on at a characteristic proper time \( \tau_{\mathrm{char}} \). Unlike ensemble-averaged, non-causal Page-curve phenomenology, this law follows directly from bounded Tomita--Takesaki modular flow and is fully invertible from simulated or empirical retrieval curves. The framework converts global entropy conservation into a Lorentzian-causal, observer-specific retrieval process, without invoking global reconstruction or post hoc averaging. It predicts distinct retrieval trajectories for stationary, freely falling, and accelerated observers, and yields an acceleration-indexed \( g^{(2)}(t_{1}, t_{2}) \) envelope that Bose--Einstein--condensate analog black holes can measure on 10–100 ms timescales. Recent laboratory observations of universal coherence-spreading bounds in ultracold quantum gases provide independent empirical support for access-limited saturation dynamics. Numerical validation on a 48-qubit MERA lattice (bond dimension~8) confirms robustness. A modified Ryu–Takayanagi prescription embeds the retrieval dynamics in \( \mathrm{AdS/CFT} \) without replica-wormhole or island constructions. By replacing ensemble-averaged Page curves with a causal, testable retrieval mechanism, the model reframes the black-hole information paradox as an experimentally accessible dynamical question. Here \( S_{\max} \) denotes the Bekenstein--Hawking entropy, \( \gamma(\tau) \) the modular-flow retrieval rate, and \( \tau_{\mathrm{char}} \) the characteristic proper-time scale.

Abstract: Recent experimental demonstrations of the Montgomery effect have revealed the possibility of controlled, lensless self-focusing and three-dimensional reconstruction of optical fields in free space. In this work, we present a geometric interpretation of this phenomenon based on the Kuznetsov tensor formalism, offering an alternative theoretical framework that extends beyond conventional wave-interference descriptions.Within this approach, the propagation of a coherent optical field is treated as an evolution of field configurations in an effective configuration space with a dynamically modified metric. The spatial phase modulation imposed at the initial plane induces phase-dependent singularities encoded by the Kuznetsov tensor, which alters the geometry of the configuration space. As a result, light propagation follows geodesics of the effective metric rather than straight trajectories in Euclidean space.We show that the characteristic features of the Montgomery effect—namely, periodic self-reconstruction, discrete refocusing planes, and the robustness of complex structured beams—naturally arise as consequences of the geometric evolution governed by a modified flow equation involving the Kuznetsov tensor. The observed refocusing planes correspond to stable critical points of a configurational entropy functional, explaining the sharp re-emergence of optical structures without the use of physical focusing elements.Furthermore, the successful reconstruction of vortex beams and multi-spot arrays indicates the preservation of topological invariants of the optical field, which is naturally described within the tensor-geometric framework. This interpretation provides a unified explanation for the stability and repeatability of the Montgomery effect and establishes a direct conceptual link between structured light, geometric self-organization, and effective curvature of configuration space.The proposed framework offers new theoretical insights into lensless optical manipulation and suggests pathways for extending Montgomery-type effects to metasurfaces and volumetric optical architectures.

Abstract: The Prime Representing Constant infinitely generates prime numbers. We discovered how to compute the Prime Representing Constant using the Hadamard product expansion. We also modified the classical Riemann–von Mangoldt explicit formula. While mathematically equivalent to the classical formula, the cosine-phase form is novel in its computational and structural presentation, enabling faster, memory efficient, and intuitive computation of ψ(x). Combining all the properties will give us a trace-type oscillatory operator that infinitely generates prime numbers.