Search Results (335)

Background/Objectives: Acute total sleep deprivation (TSD) is known to impair working memory capacity. However, the specific relationship between alterations in the brain’s electrical power spectrum following TSD and working memory deficits remains poorly understood. Methods: In this study, 30 healthy young adults (14 males and 16 females) were enrolled, and 28 participants were finally included in the analysis after excluding EEG data with excessive noise, who underwent a verbal working memory task under two conditions: baseline sleep (BL) and 36 h of TSD. EEG data were recorded concurrently. Results: We observed a significant decrease in working memory accuracy and a significant prolongation of reaction time after TSD. Furthermore, TSD led to a significant enhancement of parietal alpha-ERD (at electrodes P3/Pz/P4) and theta-ERS, accompanied by a reduction in N2 and P3 wave amplitudes. Conclusions: These findings suggest that TSD may impair working memory by weakening parietal alpha-ERD and early conflict monitoring and late attention evaluation processes. The enhanced theta-ERS might represent a compensatory mechanism. Full article

This study presents a systematic comparative benchmark between two distinct paradigms for solving nonlinear partial differential equations (PDEs): the data-driven Physics-Informed Neural Networks (PINNs) and the analytical Homotopy Analysis Method (HAM). We apply both methods to a unified family of canonical PDEs, the Burgers, Huxley, Fisher, Burgers–Huxley, and Burgers–Fisher equations, under identical problem setups, domain discretization, and validation metrics. PINNs incorporate physical laws directly into neural network training by minimizing a loss function that enforces PDE residuals, yielding physically consistent solutions even for strongly nonlinear problems. HAM provides approximate analytical solutions using a unified framework, and the same initial guess, auxiliary linear operator, and auxiliary function across all equations despite their distinct nonlinearities. The controlled, consistent application of both methods enables a fair, reproducible comparison across this equation family. The results provide a quantitative performance map under identical conditions, delineating when PINNs (high accuracy, long-term stability, and generalization capability) are preferable, versus when HAM (computational speed, short-term analytic approximation, and lower memory footprint) offers advantages. While the finite radius of convergence of the truncated HAM series is theoretically expected, our controlled comparison quantifies for the first time how this degradation varies across equation types, revealing that the choice between methods depends on specific problem requirements including error tolerance, available computational resources, and temporal horizon. The novelty lies not in solving each equation individually, but in deriving a performance taxonomy that systematically connects equation features (shocks, stiffness, and reaction–diffusion coupling) to optimal solver choice—providing previously unavailable, evidence-based guidance for the scientific computing community. This study establishes the first rigorous, controlled comparative benchmark between analytic and data-driven PDE solvers across a spectrum of nonlinearities, providing a reproducible baseline for future hybrid scientific machine learning solvers. Full article

The plugging of fractured gas reservoirs with severe lost circulation during oil and gas drilling and production has long been challenged by technical issues such as low plugging strength and short effective duration. This paper reports the preparation of a high-strength supramolecular gel plugging agent via micellar copolymerization based on the synergistic effects of hydrophobic association and hydrogen bonding. Systematic optimization determined the optimal synthesis formula: acrylamide (AM) 12%, 2-acrylamido-2-methylpropanesulfonic acid (AMPS) 2%, stearyl methacrylate (SMA) 0.4%, sodium dodecyl sulfate (SDS) 1.5%, and potassium persulfate 0.3%, with a reaction temperature of 60 °C. Performance evaluations revealed that the gel possesses a controllable gelation time (120 min) and excellent viscoelastic recovery properties. At a compressive strain of 87%, the compressive stress reached 1.43 MPa while maintaining structural integrity. Swelling behavior analysis indicated that the gel follows a non-Fickian diffusion mechanism, with its swelling process governed by the synergistic interplay of water molecule diffusion and polymer network relaxation. Core plugging experiments demonstrated that the gel achieved plugging efficiencies exceeding 95% for cores with permeabilities ranging from 0.18 to 0.90 μm², with a maximum breakthrough pressure gradient of up to 11.48 MPa/m. These results highlight the gel’s efficient and broad-spectrum plugging capability for fractured lost circulation zones. This preliminary study provides experimental foundations for the material design and performance optimization of supramolecular gel-based long-lasting plugging agents for severe lost circulation gas reservoirs, and further field-scale validation is required for engineering application. Full article

Quantum biology is a multidiscipline which analyses possible critical aspects of life that could be based on the macroscopic expression of quantum phenomena. The high efficiency of light energy harvesting in green sulfur bacteria during photosynthesis is associated with entanglement and tunneling effects in the Fenna–Mathew–Olson complex. This has been studied to assess itscontribution, when conducting the light energy captured by the chlorosome, to the reaction center, where it is transformed into chemical energy. This work analyses, in the quantum domain, the coherence and entanglement between those two components associated with a general non-localized absorption spectrum in the pigments serving as input antennas. This study first imposes a more symmetric structure on the absorption spectrum, revealing certain relations which, when it is partially broken and parametrized on the most feasible pigments, displays a characteristic spectrum associated with the nature of the bacteria studied, in terms of their habitat and evolutionary survival. Finally, a brief insight analysis of similarities and differences in the protein sequence of the complex is conducted to trace possible traits relating them to some of the previous quantum features and suggesting some responsible positions within the FMO protein sequence. Full article

The construction of Z-scheme heterojunctions is regarded as one of the most effective modification strategies for photocatalysts. However, how to improve the interfacial charge transfer efficiency to further enhance the photocatalytic activity remains an urgent issue to be addressed. In this study, sulfur vacancy-enriched ZnIn₂S₄/MoS₂ Z-scheme heterojunctions (V-ZIS/MS) containing interfacial Mo-S bonds was successfully synthesized using a hydrothermal method. The V-ZIS/2%MS showed the highest hydrogen evolution rate, achieving 19.21 ± 0.78 mmol·g⁻¹·h⁻¹ under visible light and 112.89 ± 10.98 mmol·g⁻¹·h⁻¹ under full-spectrum illumination, which are 5.07 and 4.41 times higher than ZIS (3.79 ± 0.79 mmol·g⁻¹·h⁻¹) and V-ZIS (4.36 ± 0.98 mmol·g⁻¹·h⁻¹) under visible light, respectively, outperforming most reported ZIS-based photocatalysts. This is because the composite of V-ZIS and MS enhanced its light absorption performance. More importantly, the formation of Mo-S bonds at the V-ZIS/MoS₂ interface facilitated efficient charge transfer and reduced interfacial resistance, leading to significantly improved photocatalytic activity. Cycling experiments further demonstrate that V-ZIS/2%MS exhibits considerable photocatalytic stability. X-ray diffraction analysis before and after the reaction further confirmed the structural stability of the catalyst. This work provides a certain reference for the preparation of high-performance ZIS-based photocatalysts. Full article

Background: Children with autism spectrum disorders (ASD) are generally less involved in physical activity and sport. Therefore, the present pilot study aimed at determining the effect of a sport-based training program on motor coordination development and functioning in children with ASD. Methods: Twenty children with ASD (age: 8.7 ± 1.6 years, 5 females) were included in a sport-based training program for 6 months. Participants were free to select their own sport discipline. Before and after the program, reaction time was evaluated using a simple (by identifying the targeted stimulus) and a complex (by discriminating the targeted stimulus among confounding signals) reactive test, while fine and gross motor coordination was assessed by transferring pennies, jumping in place (same sides synchronized), tapping feet and fingers (same side synchronized), and the Flamingo test. Results: The analysis showed a significant reduction (p = 0.016, d = 0.16) in complex reactive test (pre: 15.8 ± 14.8 s; post: 13.6 ± 11.1 s) and a significant improvement in transferring pennies test (pre: 6.3 ± 3.4 pt.; post: 7.8 ± 3.8 pt.; p = 0.034, d = 0.42). Furthermore, two of the low-functioning children, who did not perform any motor test before the program, were able to complete both reactive tests and transferring pennies test. No significant differences emerged for the remaining tests. Conclusions: A sport-based extra-curricular program improved reaction time and fine motor coordination in children with ASD. The complex reactive and transferring pennies tests were particularly effective in detecting changes, even in low-functioning children. These findings support the promotion of diverse physical activities to aid physical and cognitive development. Full article

Objective: The main aim of the study was to evaluate the role of wild fishes inhabiting in three anthropogenic-impacted Bays in Chile as reservoirs of antimicrobial resistance genes (ARGs). Methods: A total of 245 antimicrobial-resistant isolates were isolated from fish captured in the Coquimbo (142 isolates), Concepción (44 isolates), and Puerto Montt (59 isolates) Bays, and were identified by 16S rRNA gene sequence analysis, Antimicrobial-resistant isolates were tested for susceptibility to 12 antimicrobials by an agar disk diffusion method, and the carriage of genes encoding for resistance to main antimicrobial classes, such as β-lactams, amphenicols, tetracyclines, and sulfonamides by PCR (Polymerase Chain Reaction). Results: A predominance of the Pseudomonas (37.04%), Vibrio (14.40%), and Shewanella (13.99%) genera. Antimicrobial-resistant isolates were tested for susceptibility to 12 antimicrobials by an agar disk diffusion method, showing highest resistance to streptomycin (82.4%), amoxicillin (67.4%), and furazolidone (63.3%), and lowest resistance to ciprofloxacin (3.7%), meropenem (22.5%), and oxytetracycline (29.8%) and exhibiting a high occurrence of the multi-drug resistance phenotype (76.9%). Furthermore, an important number of isolates recovered from sampled fish species carried plasmids (53.5%), floR gene (36.7%), and tet genes (19.2%), whereas the detection of sul genes and class 1-integron was rare. As an overall result, 10.6% of isolates carried at least one bla gene, encoding an extended-spectrum-β-lactamase, with a high predominance of the bla_CTX-M1 gene (23 isolates), whereas 14 out of 245 isolates (5.7%) were positive for the carriage of carbapenemases encoding genes, which both groups exhibited the β-lactam resistance phenotype. Conclusions: The wide distribution of ARG-carrying bacteria in wild fishes from all sampled Bays provides evidence that wild fish are important reservoirs and drivers of spread of ARGs in the marine environment, prompting the need of a continuous surveillance of these genes in wild fishes inhabiting anthropic impacted coastal marine environments in Chile. Full article

Background/objectives: A rise in infections associated with carbapenem-resistant Providencia species (CRPS) has been observed worldwide. This study presents a genomic analysis of CRPS isolates from four hospitals in Croatia and the outpatient setting, in order to determine the extent of the spread of CRPS in Croatia. In the present study, we applied a combination of phenotypic characterization and molecular analysis of resistance traits to determine the mechanisms and the routes of spread of CRPS. Material and methods: The antibiotic susceptibility testing was performed using disk-diffusion and broth dilution methods. The nature of extended-spectrum β-lactamases (ESBLs), carbapenemases, and fluoroquinolone resistance determinants was investigated by polymerase chain reaction (PCR). In order to obtain an insight into the whole resistome, selected isolates were subjected to the Interarray Genotyping Kit CarbaResist and whole genome sequencing (WGS). Results: In total, 30 isolates were collected from four centers, located in different geographic regions of Croatia. There was uniform resistance to piperacillin-tazobactam, cefuroxime, expanded-spectrum cephalosporins (ESCs), imipenem, ertapenem, meropenem, and ciprofloxacin. Immunochromatographic testing and PCR revealed OXA-48 and NDM carbapenemase in 15 isolates, respectively. Phenotypic tests for ESBLs were positive in all OXA-48 and one NDM-positive organism (16 isolates). The isolates were categorized as extensively drug-resistant (XDR). OXA-48-producing isolates were susceptible only to ceftazidime-avibactam, whereas NDM producers were susceptible to cefiderocol and, in the majority of cases, also to amikacin. WGS identified a plethora of genes encoding resistance to aminoglycosides, such as aadA1 and aadA2, (aph(3″)-Ib and aph(6)-Id, sulfonamides sul1 and sul2, trimethoprim dfrA1, dfrA10, and dfrA12, tetracyclines tet(A) and tet(B), and chloramphenicol catA3 and catA5. Conclusions: Providencia spp., in spite of being a rare pathogen, should be included in the surveillance studies across the medical centers in Croatia. Full article

It is well-known that GNSS high accuracy solutions are increasingly vulnerable to jamming and spoofing attacks, posing significant challenges to their reliability, security, and accuracy. In the past years, GNSS communities have witnessed an increase in the frequency and sophistication of these attacks, driven, among other factors, by the widespread availability of low-cost, off-the-shelf equipment capable of denying or even totally misleading GNSS-based positioning systems. On the one hand, jamming attacks aim at inhibiting signal reception by introducing high-power noise or interference, leading to degraded performance or complete failure in determining position. Jamming detection mechanisms need to be traced to GNSS receiver mitigation measures at signal processing level to analyze the radio frequency (RF) environment or receiver behavior. Signal-to-noise ratio (SNR) monitoring, power spectrum analysis, and signal power monitoring are commonly used to detect anomalies in signal characteristics. Jamming is often indicated with the presence of a combination of one or more dedicated indicators, opening space to characterize different levels of jamming attack allowing to optimize a response at user level. On the other hand, detecting spoofing attacks requires different advanced techniques to identify anomalies in satellite signals, receiver behavior, or consistency of computed position data. Indicators regarding internal consistency checks, as well as unexpected evolutions of GNSS signals, are typically suspicious behaviors to be analyzed as possible attacks. Additionally, ensuring trust in the received navigation information by including cryptographic authentication mechanisms is key to quickly detecting some kinds of spoofing. This paper presents the latest enhancements on jamming and spoofing detection and mitigation mechanisms for GMV GSharp^® high accuracy and safe positioning solution. This new method, based on fuzzy logic systems, allows us to distinguish between different levels of attack and adapt the reactions to reduce the impact on the final user as much as possible. Additionally, test results obtained from real GNSS attacks datasets will be shown. Full article

Photocatalysis is a process in which a material utilizes light energy to degrade contaminants through oxidation reactions that decompose impurities upon contact with its surface. Titanium dioxide is one of the most widely used semiconductor materials due to its abundance, chemical stability, and non-toxicity. However, its relatively wide bandgap restricts its photocatalytic activity to the ultraviolet region of the solar spectrum, limiting its overall efficiency under natural sunlight. The incorporation of copper nanoparticles into the TiO₂ matrix enhances light absorption by extending its activity into the visible range, thereby improving its energy conversion efficiency. In this study, undoped and Cu-doped TiO₂ powders were synthesized using the mechanochemical method. The characteristics of the prepared photocatalyst material were determined by XRD, SEM, absorbance, and chemical analysis. XRD analysis showed the formation of TiO₂ in its anatase and rutile phases. Sphere-like shapes with a size of 100 nm were inferred from SEM images. The photocatalytic tests revealed that the Cu-doped TiO₂ nanoparticles exhibited high photocatalytic activity in degrading contaminated water. This enhancement can be attributed to the formation of oxygen vacancies, which promote the photodegradation of organic compounds. Full article

Background: Autism Spectrum Disorder (ASD) involves social, emotional, and behavioral challenges, and conventional therapies show limited effectiveness. Aims: To evaluate the effect of Yoga Therapy (YT) on neurophysiological regulation and behavioral functioning in individuals with ASD. Methods: Thirty-six autistic individuals, aged 6 to 25 years and with Childhood Autism Rating Scale (CARS) scores above 15, were randomly assigned to yoga (YG) and control (CG) groups. YG received 60 min YT sessions twice weekly for six months alongside a regular school routine, while CG followed only a regular school routine. Handgrip strength (HGS), visual reaction time (VRT), systolic (SBP) and diastolic (DBP) blood pressure, heart rate (HR), and CARS scores were assessed at pre-, mid-, and post-intervention. Repeated measures ANOVA and Pearson’s correlation were used for statistical analysis. Results: The study showed an increase in HGS (Δ = 3.27 kg) and a reduction in VRT (Δ = −523.86 ms) with a marked decrease in total CARS score (Δ = −5.67), p < 0.01 in YG. There was a mild, non-significant reduction in cardiovascular (CV) dysfunction in YG, while CG showed no significant changes across all measures. Conclusion: Biweekly YT sessions over six months enhanced neurophysiological regulation, improving sensorimotor integration and accelerating cognitive, emotional, and behavioral outcomes in individuals with ASD. Full article

Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by impairments in social interaction and communication, along with atypical behavioral patterns. Affected individuals often seem isolated in their inner world and exhibit particular sensory reactions. The World Health Organization has indicated a persistent increase in the global prevalence of autism, with approximately 1 in 127 persons affected worldwide. This study contributes to the growing research effort by presenting a comprehensive analysis of functional connectivity patterns for ASD prediction using rs-fMRI datasets. A novel approach was used for ASD identification using the ABIDE II dataset, based on functional networks derived from BOLD signals. The sparse functional brain connectome (Lean-NET) model is employed to construct subject-specific connectomes, from which local graph metrics are extracted to quantify regional network properties. Statistically significant features are selected using Welch’s t-test, then subjected to False Discovery Rate (FDR) correction and classified using a Support Vector Machine (SVM). Our experimental results demonstrate that locally derived graph metrics effectively discriminate ASD from typically developing (TD) subjects and achieve accuracy ranging from 70% up to 91%, highlighting the potential of graph learning approaches for functional connectivity analysis and ASD characterization. Full article

Background: Elevated heart rate (HR) reactivity to psychomotor challenge mirrors greater proneness to acute stress, which is a disadvantage in competitive sports. This study investigated whether temperament and adiposity predict HR reactivity during a reaction time (RT) task in adolescent athletes, with a focus on identifying their role in psychophysiological vulnerability. Participants and procedure: The participants were 20 adolescent canoe athletes (15 boys, 5 girls; mean age = 14.3 ± 1.88 years). They were volunteers recruited from a canoe club, with the permission of their coaches and parents. The study was conducted in a controlled laboratory setting, where participants underwent anthropometric tests, completed a questionnaire, had a HR monitor fitted, and rested in an armchair until a relatively stable HR (±5 beats per minute) was recorded. Subsequently, their HR was monitored across three 5 min phases: baseline, RT task, and recovery. Reactivity was calculated as the difference between task and recovery, because pre-task HR was influenced by anticipation. Data analyses were performed using AI-assisted and verified Bootstrapped Spearman correlations, Lasso regression with five-fold cross-validation, and stability analysis with 25 repeated cross-validations. Results: Shyness and body fat percentage were positively related to HR reactivity, whereas other temperament traits and RT performance showed no statistically significant associations. The Lasso regression results revealed shyness and adiposity as significant predictors, with their interaction consistently identified as the strongest effect (selected in 76% of models). The independent measures did not affect HR in the recovery phase. Conclusions: Shy adolescents with higher adiposity demonstrate heightened stress responses, as evidenced by HR reactivity, underscoring the importance of addressing stress vulnerability in young athletes and extending this line of inquiry to a broader spectrum of junior athletes. Full article

Background: Infections caused by antimicrobial-resistant bacteria are difficult to treat and increase the risk of death in animals. This report describes a fatal case of diarrhea in a horse that, despite intensive treatment including surgery and broad-spectrum antimicrobials (ceftiofur and amikacin), experienced a worsening of its condition and subsequent death. Methods: A fecal swab sample was subjected to microbiological culture for the identification of bacteria and assessment of their phenotypical antimicrobial susceptibility profiles using the disk-diffusion and broth microdilution methods. The double-disk synergy test, polymerase chain reactions for the detection of genes encoding extended-spectrum β-lactamases, and whole-genome sequence-based analysis were also performed. Results: Strains of Salmonella enterica and Escherichia coli were isolated, with the E. coli strain DSL-HVUVV-2025 presenting resistance to a third-generation cephalosporin. Accordingly, the bla_CTX-M-2 gene was identified in the DSL-HVUVV-2025 strain, which was submitted to whole-genome sequencing. Genomic analysis showed several antimicrobial resistance determinants, as well as virulence genes, including those associated with the enteroaggregative pathotype. The bla_CTX-M-2 gene was surrounded by an ISCR1 element and embedded in a complex class 1 integron that is part of the Tn7337 transposon. Strain DSL-HVUVV-2025 belonged to a novel sequence type. Conclusions: This case highlights the importance of monitoring antimicrobial resistance and performing genomic characterization of bacteria involved in equine diarrhea to guide effective clinical management in veterinary hospitals. It also reinforces the role of horses as potential carriers of WHO critical priority pathogens and the need for responsible antimicrobial use. Full article

We have investigated the structural, morphological, magnetic, and up-conversion luminescence properties of the Yb³⁺/Er³⁺-doped LiGdF₄ nanocrystals precipitated in the silica glassy matrix. Morphological analysis showed uniform distribution of LiGdF₄ nanocrystals (tens of nm in size), embedded in silica glass matrix. FTIR spectroscopy analysis showed trifluoracetates thermolysis with silica lattice formation and structural analysis by XRD is consistent with the LiGdF₄ crystallization process, most likely through an autocatalytic reaction. The stress and crystalline lattice distortion are assigned to the doping and glass matrix environment where the growth process occurs. The EPR spectra associated with the Gd³⁺ ions have shown a well-defined spectrum in the xerogel, associated with the trifluoroacetate ligand environment. In the LiGdF₄ nanocrystals, the broad and unresolved spectrum is due to an envelope of unresolved anisotropic fine structure and a high dipole–dipole interaction between the Gd³⁺/Yb³⁺/Er³⁺ paramagnetic ions. Under 980 nm laser light pumping, we observed the characteristic “blue”, “green” and “red” up-conversion luminescences of the Er³⁺ ions through Yb → Er energy transfer process, that imply three and two-photon process; near UV up-conversion luminescence of Gd³⁺ is observed at about 280–300 nm where Yb → Er and Er → Gd energy transfer is involved. The UC luminescence properties can be improved up to two times by additional Yttrium co-doping due to the induced crystal field distortion. Full article