Search Results (246,408)

Background: Spinal anesthesia is a widely used technique for pain control in surgical procedures, requiring effective drug distribution within the cerebrospinal fluid (CSF) for optimal outcomes. The distribution is influenced by injection parameters such as needle diameter and injection speed, which, if not optimized, can reduce efficacy or cause side effects. This study investigates how these parameters affect drug distribution in the CSF using computational fluid dynamics (CFD). Material Methods: An anatomically accurate three-dimensional model of the CSF space was created using MRI data. Simulations were performed using three needle tips (22 G, 25 G, 27 G) and different injection rates at the L4–L5 vertebral level. The model included physiological CSF oscillations from cardiac and respiratory cycles. Drug dispersion was analyzed in terms of spatial distribution and concentration changes over time. Results: The findings obtained show that the combination of a large-gauge needle (22G) and high injection speed provides wider distribution within the CSF and more effective transport to the cranial regions. On the other hand, with a small-gauge needle (27G) and low injection speed, the drug remained more localized, and access to the upper spinal regions was limited. Additional parameters such as injection duration, direction, and flush applications were also observed to significantly affect distribution. Conclusions: CFD modeling reveals that injection parameters significantly affect drug dispersion patterns in spinal anesthesia. Optimizing these parameters may improve therapeutic outcomes and reduce complications. The model provides a foundation for developing personalized intrathecal injection protocols. Full article

The low efficiency of the microbial gasification of coal limits the application of bio-coal bed methane technology. The co-fermentation of coal and biomass provides a new approach for improving the degradation rate of coal. In this study, a co-fermentation system comprising five different coal orders with five microalgae was constructed in the laboratory, and the methanogenic characteristics of coal–algae co-fermentation and its microbiological mechanism were systematically investigated in terms of gas production, soluble organic matter, and microbial community characteristics. The results showed that the combination of lignite and Nannochloropsis exhibited optimal methane production, with a methane yield of 26.43 mL/g coal. Biogenic methane yields for lignite–Porphyra and anthracite–Porphyra were 23.43 mL and 21.28 mL, respectively, demonstrating the potential for algae to enhance gas production even in high-rank coals. pH monitoring revealed that algal species played a critical role in the acidification process. Dunaliella caused a continuous pH decrease, reaching 3.76 by day 30, while Nannochloropsis maintained a neutral pH of 6.95, optimizing the fermentation environment. Significant differences in soluble organic matter were observed between the lignite and anthracite fermentation systems, with lignite systems producing more volatile fatty acids, including acetic and butyric acids. Microbial community analysis revealed that Methanosarcina, an acetic acid-utilizing methanogen, was dominant in lignite and anthracite systems, while Syntrophomonas played a key role in lignite–Nannochloropsis co-fermentation. These findings provide valuable insights into optimizing coal microbial gasification and selecting appropriate algal species to enhance methane production efficiency. Full article

Ionospheric scintillation represents a disturbance phenomenon induced by irregular electron density variations, predominantly occurring in equatorial, auroral, and polar regions, thereby posing significant threats to Global Navigation Satellite Systems (GNSS) performance. Polar regions in particular confront distinctive challenges, including the sparse deployment of dedicated ionospheric scintillation monitoring receiver (ISMR) equipment, the limited availability of strong scintillation samples, severely imbalanced training datasets, and the insufficient sensitivity of conventional Deep Neural Networks (DNNs) to intense scintillation events. To address these challenges, this study proposes a modeling framework that integrates residual neural networks (ResNet) with the Synthetic Minority Over-sampling Technique for Regression with Gaussian Noise (SMOGN). The proposed model incorporates multi-source disturbance features to accurately estimate phase scintillation indices (σ_φ) in polar regions. The methodology was implemented and validated across multiple polar observation stations in Canada. Shapley Additive Explanations (SHAP) interpretability analysis reveals that the rate of total electron content index (ROTI) features contribute up to 64.09% of the predictive weight. The experimental results demonstrate a substantial performance enhancement compared with conventional DNN models, with root mean square error (RMSE) values ranging from 0.0078 to 0.038 for daytime samples in 2024, and an average coefficient of determination (R²) consistently exceeding 0.89. The coefficient of determination for the Pseudo-Random Noise (PRN) path estimation results can reach 0.91. The model has good estimation results at different latitudes and is able to accurately capture the distribution characteristics of the local strong scintillation structures and their evolution patterns. Full article

In China, most of the ancient wooden structure mortise and tenon buildings, under the long-term upper load, have columns with surface surfaces that have varying degrees of damage, which need to be repaired and strengthened urgently, but the theory related to CFRP, mortise size, and pre-damage simulation still needs to be deeply studied. To investigate the effects of CFRP reinforcement layers, cross-sectional area of concealed tenons as the projected area after installation, and tenon engagement length as the axial length after installation on the axial compressive mechanical properties of pre-damaged quad-segment spliced Pinus sylvestris var. mongolia composited wooden columns, axial compression failure tests were conducted on 10 specimens following pre-damage simulation and CFRP strengthening. The experimental program yielded comprehensive data, including observations, mechanical analyses, load-displacement curves, load-strain curves, ultimate load-bearing capacities, ductility coefficients, and stiffness values. The results demonstrate that with consistent tenon cross-sectional area and engagement length, increasing CFRP layers from 1 to 3 raises the ultimate bearing capacity from 472.3 kN to 620.3 kN and improves the ductility coefficient from 4.67 to 7.95, clearly indicating that CFRP reinforcement significantly enhances axial compressive performance while effectively mitigating brittle failure. When maintaining constant CFRP layers and tenon cross-sectional area, extending the tenon engagement length from 30 mm to 90 mm elevates the bearing capacity from 494.95 kN to 546.3 kN and boosts the ductility coefficient from 5.58 to 7.95. In contrast, with fixed CFRP layers and engagement length, expanding the tenon cross-sectional area from 360 mm² to 810 mm² produces only marginal bearing capacity improvement from 548.2 kN to 556.2 kN with ductility coefficients ranging between 4.67 and 5.56, conclusively revealing that tenon engagement length has substantially greater influence on mechanical properties than cross-sectional area. The optimal axial compressive performance configuration combines 3 CFRP layers, an 810 mm² tenon cross-section, and a 90 mm engagement length.   Full article

Background/Objectives: Quantitative approaches to talent identification in youth soccer often rely on either closed-skill assessments or small-sided games, but each carries inherent uncertainties that can reduce selection accuracy. Effective talent selection requires integrating both sources of data while accounting for their limitations. This study aimed to develop and validate a framework that combines closed-skill tests with competitive 1v1 game outcomes to optimize early-stage player selection. Methods: We assessed the dribbling and sprinting performances of 30 Brazilian youth players and used 1308 individual 1v1 bouts (70–90 bouts/individual) to estimate competitive abilities using a Bayesian ordinal regression model. Based on our empirical results, we then ran simulations to determine how many players should be selected when the aim is to reduce a player pool of 100 individuals so that the ‘true’ top 10 performers are reliably included and to determine how the weighting between data from closed-skill tests and games should change with increasing match observations. Results: Dribbling speed was a strong predictor of 1v1 success (β = –0.76, 95% CI: [–1.16, –0.40]), while sprint speed (β = 0.01, 95% CI: [–0.36, 0.40]) showed no significant association with 1v1 success. Simulations revealed that 26.0 ± 2.5 players were needed after five 1v1 contests per player to capture the true top 10% and then decreased to 18.0 ± 1.5 players after 20 contests. Optimal weighting shifted from a greater reliance on dribbling-based data (α > 0.80 at Game 0) to more match-based data after 10–20 contests per player (α = 0.16 at Game 20), but utilizing both sources of data improved selection accuracies and efficiencies. Conclusions: This study provides an uncertainty-aware protocol for talent identification that optimizes the integration of data from closed-skill tests and in-game performances within a dynamic selection framework that enhances precision and forms the basis for efficient early-stage scouting of large cohorts of players. Full article

Background/Objectives: Vertical growth pattern significantly influences facial aesthetics and treatment choices. Lateral cephalograms are routinely used for the evaluation of vertical jaw relationships in orthodontic diagnosis. The aim of this study was to evaluate the performance of deep learning algorithms in classifying cephalometric radiographs according to vertical skeletal growth patterns without the need for anatomical landmark identification. Methods: This study was carried out on lateral cephalometric radiographs of 1050 patients. Cephalometric radiographs were divided into 3 subgroups based on FMA, SN-GoGn, and Cant of Occlusal Plane angles. Six deep learning models (ResNet101, DenseNet 201, EfficientNet B0, EfficientNet V2 B0, ConvNetBase, and a hybrid model) were employed for the classification of the dataset. The performances of the well-known deep learning models and the hybrid model were compared for accuracy, precision, F1-Score, mean absolute error, Cohen’s Kappa, and Grad-CAM metrics. Results: The highest accuracy rates were achieved by the Hybrid Model with 86.67% for FMA groups, 87.29% for SN-GoGn groups, and 82.71% for Cant of Occlusal Plane groups. The lowest accuracy rates were achieved by ConvNet with 79.58% for FMA groups, 65% for SN-GoGn, and 70.21% for Cant of Occlusal Plane groups. Conclusions: The six deep learning algorithms employed demonstrated classification success rates ranging from 65% to 87.29%. The highest classification accuracy was observed in the FMA angle, while the lowest accuracy was recorded for the Cant of the Occlusal Plane angle. The proposed DL algorithms showed potential for direct skeletal orthodontic diagnosis without the need for cephalometric landmark detection steps. Full article

Background/Objectives: Meningococcal disease (MD) remains a significant public health concern worldwide. In Serbia, mandatory immunization against MD with the meningococcal polysaccharide vaccine (MenAC) for high-risk groups and international travelers was introduced in 2006. Since 2017, the polysaccharide vaccine has been replaced with the quadrivalent meningococcal conjugate vaccine (MenACWY). The aim of this study was to analyze long-term trends in incidence, age-specific patterns, seasonality, and lethality of invasive meningococcal disease (IMD) in the Autonomous Province of Vojvodina (AP Vojvodina), Serbia, over a 28-year period. Methods: A descriptive study analyzed all reported cases of IMD in AP Vojvodina, from 1997 to 2024. Data were obtained from the regional communicable disease surveillance system, based on mandatory hospital reporting and case classification according to national and WHO guidelines. Temporal, demographic, and clinical characteristics, along with disease outcomes, were analyzed. Results: From 1997 to 2024, 175 IMD cases were reported in AP Vojvodina. The annual incidence peaked in 1997 (1.24/100,000), with smaller surges in 2003 and 2005. Since 2006, coinciding with the introduction of immunization against MD, a sustained decline has been observed, with incidence rarely exceeding 0.30/100,000. A slight resurgence occurred in 2023–2024, with 13 cases reported. From 1997 to 2024, IMD in AP Vojvodina exhibited a clear seasonal pattern, with most cases occurring in winter and early spring, peaking in January (17%), March (12%), and February (11%), and the fewest cases occuring in the summer months. Throughout the study period, the highest IMD incidence rates were consistently observed among infants <1 year of age and children aged 1–4 years, with peaks of up to 22.9/100,000 and 16.0/100,000, respectively. Incidence was much lower in older age groups, especially adults. After a 2006 peak, rates declined across all ages, with a slight resurgence in 2023–2024 among children and adolescents. Children aged 1–4 years made up the largest share of IMD cases, peaking in January–March (45.1%). Half of the infant cases were recorded in October–November, while cases in older children, adolescents, and adults were fewer and showed varied monthly patterns, with small peaks in winter and early spring. During the 28-year study period, the highest IMD mortality rate was observed among infants <1 year of age (0.59 per 100,000 population), followed by children aged 1–4 years (0.32 per 100,000). Mortality rates declined progressively with increasing age, with the lowest rate recorded among individuals aged ≥40 years (0.01 per 100,000). Of the 175 IMD cases reported in AP Vojvodina (1997–2024), 21 were fatal (case fatality rate [CFR] = 12.0%). The CFR of IMD varied across age groups. The highest CFR was observed among individuals aged ≥40 years (21.4%), followed by the 5–9 years (17.4%) and <1 year (16.7%) age groups. None of the patients had been vaccinated against MD. Fatal outcomes were more common in children aged 1–4 years and among rural residents, though differences were not statistically significant (p > 0.05). Most deaths (57.1%) occurred in the first quarter of the year. A strong association was found between clinical form and outcome, with meningococcal sepsis being significantly more frequently associated with fatality than meningitis (p = 0.0002). Deaths were sporadic over time, with most occurring within 1–2 days of notification. All confirmed fatal cases were due to serogroup B. Conclusions: MD remains a rare yet serious public health threat in AP Vojvodina. Mortality rates indicate that the public health impact of this disease is greatest among the youngest age groups; however, the risk of death, i.e., disease severity, does not appear to be age dependent. The recent rise in cases, high fatality among sepsis patients, and absence of prior vaccination among all IMD cases highlight the need for enhanced surveillance, physician education, and consideration of introducing both MenACWY and MenB vaccines for high-risk groups. Full article

Lumpy skin disease (LSD) is a contagious animal disease caused by the lumpy skin disease virus (LSDV). LSD can be transmitted through direct, indirect and insect vectors, severely impacting global cattle production. To evaluate difference in immune response and gut microbiota of 30 healthy 16–18 months old Angus cattle, treated with live attenuated or inactivated goatpox vaccine virus strains. The cattle were randomly divided into three groups (10 animals per group): Group A—goatpox live attenuated vaccine; Group B—goatpox inactivated vaccine; Group C—control (saline). Blood samples were collected on days 14, 28, 42, and 56 post-vaccination to assess hematological parameters, serum biochemical indices, and antibody levels; rectal feces were collected on day 28 for 16S rRNA analysis of gut microbiota. Results showed that, on day 28, both Group A and Group B reached their peak antibody levels (the log₁₀ value of Group A was 2.6, and that of Group B was 2.7), with about 90% of the cattle in each vaccinated group testing antibody-positive. On day 42, Group B retained 90% seropositivity, whereas Group A declined to 80%. Significantly altered in vaccinated Groups (A and B) compared to controls on days 14 and 28 (p < 0.05). Hematological parameters (PLT, NEUT, and LYM) and serum biochemical indices (AST, TP, and GGT) were elevated early after vaccination but returned to baseline by days 42 and 56.Which returned to control levels by days 42 and 56. On day 28 post-vaccination, Vaccinated cattle showed significantly higher gut microbiome richness and diversity than unvaccinated controls (p < 0.05). At the phylum level, the dominance was observed in Firmicutes and Bacteroidetes: the relative abundances were 62.90% and 29.65% in Group A, 60.84% and 30.13% in Group B, and 49.99% and 39.73% in Group C, respectively. These findings indicate that the inactivated goatpox vaccine elicits a more durable and stable antibody response, maintaining higher specific antibody titers, and induces more pronounced shifts in the gut microbiota community structure at the phylum level compared with the live attenuated vaccine. Full article

An open question in radiobiology concerns whether low doses of radiation are harmful or if cells are able to tolerate such exposure with minimal or no disruption. This issue is relevant for evaluating public health risks associated with the increasing number of medical computed tomography (CT) diagnostic procedures. This study evaluated the impact of CT scan-level exposure on human adipose mesenchymal stem cells (hMSCs) by measuring DNA damage responses (γH2AX, 53BP1, pATM foci), proliferation (Ki-67), senescence (β-galactosidase), and multiple gene expressions. Responses to one or five CT exposures were compared to a 2 Gy X-ray dose at intervals from 1 h to 10 passages post-irradiation. It was shown that CT scan briefly increased DNA damage markers but showed no significant long-term effects. A high dose of 2 Gy X-ray exposure caused sustained DNA damage, decreased proliferation, increased senescence, and significant changes in hundreds of genes even after several cell generations. After a single CT exposure, gene expression changes were minimal, while high-dose exposure led to strong activation of DNA repair and stress response pathways. Five CT scans caused a slight activation of LIF and HSPA1B genes, but these effects were minor compared to the high-dose group. All detected effects from CT scans were not observed by ten cell passages, whereas high-dose effects persisted. In conclusion, typical CT scan exposures have only short-term, mild effects on hMSCs, while high-dose radiation causes lasting cellular and genetic changes. Full article

This study investigates self-pulsation phenomena in a liquid-centered swirl coaxial injector with a recess length of 4 mm, under varying liquid flow conditions, using numerical simulations. The simulations focused on analyzing spray patterns, pressure oscillations, and dominant frequency characteristics, and the results were compared with previous experimental data. Self-pulsation, observed at liquid flow rates of 60%, 90%, and 100% of nominal values, generated distinctive periodic oscillations in the spray pattern, forming “neck” and “shoulder” breakup structures that resemble a Christmas tree. Surface waves induced by Kelvin-Helmholtz and Rayleigh-Taylor instabilities were identified at the gas-liquid interface, contributing to enhanced atomization and reduced spray breakup length. FFT analysis of the pressure oscillations highlighted a match in trends between simulation and experimental data, although variations in dominant frequency magnitudes arose due to the absence of manifold space in simulations, confining oscillations and slightly elevating dominant frequencies. Regional analysis revealed that interactions between the high-speed gas and liquid film in the recess region drive self-pulsation, leading to amplified pressure oscillations throughout the injector’s internal regions, including the gas annular passage, tangential hole, and gas core. These findings provide insights into the internal flow dynamics of swirl coaxial injectors and inform design optimizations to control instabilities in liquid rocket engines. Full article

Mechanical models are capable of simulating the deformation and stress distribution of oocytes under external forces, thereby providing insights into the underlying mechanisms of intracellular mechanical responses. Interactions with micromanipulation tools involve forces like compression and punction, which are effectively analyzed using principles of solid mechanics. Alternatively, fluid–structure interactions, such as shear stress at fluid junctions or pressure gradients within microchannels, are best described by a multiphase flow model. Developing the two models instead of a single comprehensive model is necessary due to the distinct nature of cell–tool interactions and cell–fluid interactions. In this study, we developed a finite element (FE) model of porcine oocytes that accounts for the viscoelastic properties of the zona pellucida (ZP) and cytoplasm for the case when the oocytes interacted with a micromanipulation tool. Atomic force microscopy (AFM) was employed to measure the Young’s modulus and creep behavior of these subcellular components that were incorporated into the FE model. When the oocyte was solely interacting with the fluids, we simulated oocyte deformation in microfluidic channels by modeling the oocyte-culture-medium system as a three-phase flow, considering the non-Newtonian behavior of the oocyte’s components. Our results show that the Young’s modulus of the ZP and cytoplasm were determined to be 7 kPa and 1.55 kPa, respectively, highlighting the differences in the mechanical properties between these subcomponents. Using the developed layered FE model, we accurately simulated oocyte deformation during their passage through a narrow-necked micropipette, with a deformation error of approximately 5.2% compared to experimental results. Using the three-phase flow model, we effectively simulated oocyte deformation in microfluidic channels under various pressures, validating the model’s efficacy through close agreement with experimental observations. This work significantly contributes to assessing oocyte quality and serves as a valuable tool for advancing cell mechanics studies. Full article

The stochastic model in Precise Point Positioning (PPP) defines the statistical properties of observations and the dynamic behavior of parameters. An inaccurate stochastic model can degrade positioning accuracy, ambiguity resolution, and other aspects of performance. However, due to the influence of multiple factors, the stochastic model in PPP cannot be precisely predetermined, necessitating the development of an Adaptive Stochastic Model (ASM) based on Variance Component Estimation (VCE). While the benefits of ASMs for PPP float solutions are well documented, their contributions to other performance aspects remain insufficiently explored. This paper presents a comprehensive assessment of an ASM’s impact on PPP. First, the implementation of an ASM using VCE is described in detail. Then, experimental results demonstrate that the ASM effectively captures observational conditions through the estimated variance component factors. It enhances both PPP float and fixed solutions when the predefined stochastic model is inadequate, improves cycle-slip detection by tightening the stochastic model (reducing the missed detection rate from 19% to 8%), and accelerates both direct reconvergence and re-initialization after data gaps, with reconvergence times improved by 18% and 55%, respectively. Full article

The impact of biochar pyrolyzed at 450 ± 10 °C and made from date palm (D) and olive tree (O) wastes on the hydrophysical characteristics of sandy soil was assessed in this study through a laboratory column experiment. Two different application rates (wt/wt) were tested: 1% and 5%. The prepared biochars were added at 25 °C to the upper 10 cm layers of the soil columns. The outcome showed that, in comparison to O, D biochar possessed slightly less alkalinity and more salinity. The corresponding values for pH and EC in D and O biochars were 8.99 and 4.10 dS/m and 9.42 and 2.17 dS/m. Therefore, these biochars should be used cautiously as soil amendments in saline–sodic soils because of their excessive salinity, especially D biochar. On the other hand, they are safe to employ as amendments in acidic and non-saline soils. Cumulative evaporation (CE) decreased with all treatments, and the highest decrease of 10.2% (compared to control treatments after five cycles) was observed for D biochar and 5% application rate (D450, 5%). Moreover, the available water increased by 182%, 158%, 153%, and 29% for D450, 5%, D biochar and 1% application rate (D450, 1%), O biochar and 5% application rate (O450, 5%), and O biochar and 1% application rate (O450, 1%), respectively. The saturated hydraulic conductivity decreased by 94.8%, 87.0%, 76.6%, and 35.1% for D450, 5%, D450, 1%, O450, 5%, and O450, 1%, respectively. It was also found that the date palm biochar was more efficient than olive waste biochar in decreasing the cumulative infiltration and infiltration rate. Finally, this study showed the superiority of biochar prepared from date palm trees over that prepared from olive tree waste for improving the hydrophysical properties of sandy soil. Full article

With the growing global demand for rice and the urgent need to enhance sustainable production, ratoon rice systems and selenium (Se) biofortification technologies have become important strategies. This study investigated the effects of the foliar application of ethylenediaminetetraacetic acid Se (EDTA-Se) during key growth stages of the main rice season on the yield, grain quality, and Se accumulation in ratoon rice. Two rice varieties—Fengliangyouxiang-1 (FLYX1) and Jinliangyouhuazhan (JLYHZ)—were selected for a two-year field experiment. A systematic analysis was performed on yield components, processing quality, appearance quality, nutritional quality, and Se speciation. The results showed that under an equivalent total amount of spraying EDTA-Se, the best effect on improving the yield, grain quality, and grain Se content of ratoon rice was observed at the heading stage and seven days after full heading. This treatment increased ratoon season yield by 6.45%, primarily due to enhanced grain filling rate (GF) and spikelets per panicle (SP). Processing quality was significantly improved; milled rice rate (MR) increased by 5.59–6.24% in FLYX1 and 3.38–3.52% in JLYHZ, while appearance quality also improved, with chalky grain rate (CGR) decreasing by 21.51–22.93% in FLYX1 and 14.50–14.53% in JLYHZ. These improvements were closely associated with elevated protein content and increased accumulation of selenomethionine (SM). Notably, FLYX1 exhibited higher efficiency in converting selenium to organic forms, whereas JLYHZ showed a greater accumulation of inorganic selenium, highlighting genotype-specific responses. This study confirmed that the foliar application of EDTA-Se during key growth phases of rice during the main season can synergistically optimize yield and quality in ratoon rice while achieving Se biofortification and providing a theoretical basis and technical support for improving the quality and efficiency of ratoon rice, as well as producing Se-enriched ratoon rice. Full article

Airborne and surface-residing microorganisms in indoor environments pose potential risks for infectious disease transmission. To address this issue, we developed a composite device combining a generator of vaporized free chlorine components with a fine particle removal filter. Field tests were conducted in occupied university classrooms to evaluate the device’s efficacy in reducing airborne bacterial loads. Airborne bacteria were sampled under three operational conditions [Electrolyzed (+)/Filter (+), Electrolyzed (−)/Filter (+), and Electrolyzed (−)/Filter (−)]. Significant reductions in bacterial counts were observed in the Electrolyzed (+)/Filter (+) condition, with a residual rate of 14.5% after 2.25 h (p = 0.00001). Additionally, surface contact tests demonstrated that vaporized free chlorine components, primarily consisting of hypochlorous acid (HOCl), reduced viable counts of E. coli, P. aeruginosa, and S. aureus by 59.0–99.7% even at a distance of 8.0 m. The concentrations of vaporized free chlorine components during operation remained within safe exposure limits (0–19 ppb), consistent with the effective range reported in prior literature (10–50 ppb). Computational fluid dynamics simulations confirmed the diffusion of vaporized free chlorine components throughout the room, including distant sampling points. These findings suggest the combined use of a vaporized free chlorine generator and a particulate filter effectively reduces microbial contamination in indoor environments, providing a promising approach for infection control in residential and public settings. Full article