Search Results (437,791)

The evaluation and prediction of reliability and testability of mining machinery and equipment are crucial, as advancements in mining technology have increased the importance of ensuring the safety of both the technological process and human life. This study focuses on developing a reliability model to analyze the controllability of mining equipment. The model, which examines the reliability of a mine cargo-passenger hoist, utilizes statistical methods to assess failures and diagnostic controlled parameters. It is represented as a transition graph and is supported by a system of equations. This model enables the estimation of the reliability of equipment components and the equipment as a whole through a diagnostic system designed for monitoring and controlling mining equipment. A mathematical and logical model is proposed to calculate availability and downtime coefficients for different structures within the mining equipment system. This analysis considers the probability of failure-free operation of the lifting unit based on the structural scheme, with additional redundancy for elements with lower reliability. The availability factor of the equipment for monitoring and controlling the mine hoisting plant is studied for various placements of diagnostic systems. Additionally, a logistic concept is introduced for organizing preventive maintenance systems and reducing equipment recovery time by optimizing spare parts, integrating them into strategies aimed at enhancing the reliability of mine hoisting plants. Full article

Objectives: Although peroral cholangioscopy has improved the endoscopic treatment of difficult stones, the treatment of intrahepatic stones remains challenging. The incidence of cholangitis is high when peroral cholangioscopy is used to treat intrahepatic stones. This study aimed to investigate the efficacy and safety of endoscopic treatment with peroral cholangioscopy for intrahepatic and common bile duct stones. Methods: Patients aged ≥20 years, who underwent endoscopic treatment with peroral cholangioscopy for intrahepatic or common bile duct stones at Tottori University Hospital from January 2016 to December 2022, were retrospectively evaluated to determine the efficacy and safety of the treatment. Results: Overall, 70 patients were included in this study: 22 in the intrahepatic stone group and 48 in the common bile duct stone group. Stones were smaller (8 vs. 17.5 mm, p < 0.001) and more numerous (p = 0.016) in the intrahepatic stone group than in the common bile duct stone group. Although the common bile duct stone group exhibited a higher rate of complete stone clearance in the first session, no significant differences were observed in the final results. The intrahepatic stone group had a higher incidence of cholangitis (36% vs. 8%, p = 0.007); however, all cases were mild. Conclusions: Endoscopic treatment with peroral cholangioscopy for intrahepatic stones may be associated with a higher incidence of cholangitis than that for common bile duct stones. Since saline irrigation may contribute to the development of cholangitis, it is important to be aware of intraductal bile duct pressure when performing peroral cholangioscopy. Full article

In this research paper, we consider a model of the fractional Cauchy–Euler-type equation, where the fractional derivative operator is the Caputo with order $0<\alpha <2$. The problem also constitutes a class of examples of the Cauchy problem of the Bagley–Torvik equation with variable coefficients. For proving the existence and uniqueness of the solution of the given problem, the contraction mapping principle is utilized. Furthermore, a numerical method and an algorithm are developed for obtaining the approximate solution. Also, convergence analyses are studied, and simulations on some test problems are given. It is shown that the proposed method and the algorithm are easy to implement on a computer and efficient in computational time and storage. Full article

Reinforcement learning (RL) has been shown to be effective in path planning. However, it usually requires exploring a sufficient number of state–action pairs, some of which may be unsafe when deployed in practical obstacle environments. To this end, this paper proposes an end-to-end planning method based model-free RL framework with optimization, which can achieve better learning performance with a safety guarantee. Firstly, for second-order drone systems, a differentiable high-order control barrier function (HOCBF) is introduced to ensure the output of the planning algorithm falls in a safe range. Then, a safety layer based on the HOCBF is proposed, which projects RL actions into a feasible solution set to guarantee safe exploration. Finally, we conducted a simulation for drone obstacle avoidance and validated the proposed method in the simulation environment. The experimental results demonstrate a significant enhancement over the baseline approach. Specifically, the proposed method achieved a substantial reduction in the average cumulative number of collisions per drone during training compared to the baseline. Additionally, in the testing phase, the proposed method realized a 43% improvement in the task success rate relative to the MADDPG. Full article

In this work, Surface-Enhanced Raman Spectroscopy (SERS) was employed as an effective detection technique for folpet, characterized by its notable specificity and sensitivity. The investigation involved the use of UV–Vis, Raman, and SERS spectroscopy of folpet at different concentrations for a comprehensive study of plasmon-driven effects such as plasmon resonance, plasmon hybridization, and electric field enhancement resulting in the SERS’ intensification. Specifically, SERS detection of folpet solutions at concentrations below 100 µM is presented in detail by using Ag nanoparticles prepared with hydroxylamine reduction. The experimentation encompassed diverse conditions to optimize the detection process, with Raman spectra acquired for both folpet powder and aqueous solution of folpet at the natural pH. SERS analyses were conducted across a concentration range of 9.5 × 10⁻⁸ to 1.61 × 10⁻⁴ M, employing 532 nm excitation. The differences in the spectral profiles observed for folpet Raman powder and SERS are ascribed to N–S cleavage; these changes are attributed to plasmon catalysis induced by the used Ag nanoparticles. Transmission electron microscopy (TEM) was also important in the present analysis to better understand which mechanism of nanoparticles aggregation is more favorable for the SERS detection regarding the formation of hot spots in the suspension. Complementing the experimental data, the molecular structure and theoretical Raman spectra of the folpet molecule were calculated through density functional theory (DFT) methods. The outcomes of these calculations were crucial in the elucidation of folpet’s vibrational modes. The culmination of this research resulted in the successful detection of folpet, achieving a notable limit of detection at 4.78 × 10⁻⁸ M. This comprehensive approach amalgamates experimental and theoretical methodologies, offering significant insights into the detection capabilities and molecular characteristics of folpet via SERS analysis. Full article

To address the lack of reliable measurement methods for identifying wear mechanisms and predicting the state of mechanical seal tribo-parts, this study proposes a method for characterizing tribological behavior based on measuring face vibration acceleration. It aims to uncover the source mechanism of mechanical seal face vibration acceleration influenced by tribology and dynamic behavior. This research delves into the dynamic behavior characteristics and vibration acceleration of the mechanical seal stationary ring. We explored the variation pattern of face vibration acceleration root mean square (RMS) with rotation speed, sealing medium pressure, and face surface roughness. The results indicate that under constant medium pressure, an increase in rotation speed leads to a decrease in acceleration RMS and an increase in face temperature. Similarly, under constant rotation speed, an increase in medium pressure results in nonlinear changes in acceleration RMS, forming an “M” shape, along with an increase in face temperature. Furthermore, under conditions of constant medium pressure and rotation speed, an increase in the surface roughness of the rotating ring face corresponds to an increase in acceleration RMS and face temperature. Upon starting the mechanical seal, both acceleration RMS and temperature initially increase before decreasing, a trend consistent with the Stribeck curve. Full article

Explainable Artificial Intelligence (XAI) is a research area that clarifies AI decision-making processes to build user trust and promote responsible AI. Hence, a key scientific challenge in XAI is the development of methods that generate transparent and interpretable explanations while maintaining scalability and effectiveness in complex scenarios. Rule-based methods in XAI generate rules that can potentially explain AI inferences, yet they can also become convoluted in large scenarios, hindering their readability and scalability. Moreover, they often lack contrastive explanations, leaving users uncertain why specific predictions are preferred. To address this scientific problem, we explore the integration of computational argumentation—a sub-field of AI that models reasoning processes through defeasibility—into rule-based XAI systems. Computational argumentation enables arguments modelled from rules to be retracted based on new evidence. This makes it a promising approach to enhancing rule-based methods for creating more explainable AI systems. Nonetheless, research on their integration remains limited despite the appealing properties of rule-based systems and computational argumentation. Therefore, this study also addresses the applied challenge of implementing such an integration within practical AI tools. The study employs the Logic Learning Machine (LLM), a specific rule-extraction technique, and presents a modular design that integrates input rules into a structured argumentation framework using state-of-the-art computational argumentation methods. Experiments conducted on binary classification problems using various datasets from the UCI Machine Learning Repository demonstrate the effectiveness of this integration. The LLM technique excelled in producing a manageable number of if-then rules with a small number of premises while maintaining high inferential capacity for all datasets. In turn, argument-based models achieved comparable results to those derived directly from if-then rules, leveraging a concise set of rules and excelling in explainability. In summary, this paper introduces a novel approach for efficiently and automatically generating arguments and their interactions from data, addressing both scientific and applied challenges in advancing the application and deployment of argumentation systems in XAI. Full article

Background: 18F-fluorodeoxyglucose positron emission tomography–CT (FDG-PET/CT) is useful for identifying infective endocarditis (IE) but also the detection of other concomitant septic foci. Previously, we found that FDG-PET/CT identified an osteoarthritic septic graft (OASG) in 19.1% of IE patients, frequently asymptomatic. These preliminary results encouraged us to extend our analyses to a larger population, including all patients initially explored for suspected IE, to assess the prevalence, characteristics, and OASG locations brought out by FDG-PET/CT and to identify predictive factors. Methods: From a single-center cohort of patients referred for a clinical and/or biological suspicion of IE, we included all patients who underwent FDG-PET/CT, mainly performed to confirm a prosthesis heart valve or a foreign cardiac device infection. We excluded those who did not meet the 2015 modified Duke Criteria and those for whom another infectious diagnosis was finally retained or for whom all bacterial samples were negative. Demographic, clinical, bacteriological, imaging, and therapeutic data were collected. FDG-PET/CT images were retrospectively analyzed by three blinded nuclear medicine specialists to identify OASGs. Results: We identified 72 distinct OASG locations by FDG-PET/CT in 48 of 174 patients (27.6%), mainly located in the spine (21 OASGs in 20 patients); 14 patients (8.0%) had several OASG locations. In total, 43.8% of OASG locations were asymptomatic. In multivariate analysis, the presence of OASGs was associated with musculoskeletal pain (p < 0.001) and tricuspid valve involvement (p = 0.002). Conclusions: FDG-PET/CT is useful for identifying OASGs in patients with suspected IE, especially those with tricuspid IE or musculoskeletal pain. The identification of OASGs could impact antibiotic therapy and would allow adapted orthopedic management to be proposed. Full article

We report a study on the SnS_x (x < 1) decoration of porous TiO₂ nanoparticle thin films using the ionic layer adsorption and reaction (ILAR) method. UV-vis absorption measurements revealed a direct bandgap of 1.40–2.10 eV for SnS_x (with x = 0.85) and 3.15 eV for TiO₂. Degradation of rhodamine B molecules in aqueous solutions shows that coating with a Sn-to-Ti molar ratio of 2% improves the efficiency of the photocatalytic performance of titanium dioxide, but excessive coverage decreases it. We interpret the observed behavior as due to a delicate balance of many competing factors. The formation of intimate interfaces guaranteed by the ILAR growth technique and a nearly optimal alignment of conduction band edges facilitate electron transfer, reducing electron–hole recombination rates. However, the valence hole transfer from TiO₂ to SnS reduces the oxidative potential, which is crucial in the degradation mechanism. Full article

Background and Objectives: To evaluate the clinical findings of glucose 6-phosphate dehydrogenase (G6PD) and pyruvate kinase (PK) deficiency in prolonged jaundice and to determine whether the systemic immune inflammation index (SII), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR) can be used in the diagnosis of neonatal prolonged jaundice. Materials and Methods: Among full-term neonates with hyperbilirubinemia who were admitted to Medicine Hospital between January 2019 and January 2024 with the complaint of jaundice, 167 infants with a serum bilirubin level above 10 mg/dL, whose jaundice persisted after the 10th day, were included in this study. Results: G6PD activity was negatively correlated with NLR, SII, age, and hematocrit (Hct). There was a weak negative correlation between G6PD and NLR and a moderate negative correlation between G6PD activity and SII when adjusted for age and Hct. PK activity showed no significant correlation with G6PD, NLR, PLR, SII, age, and Hct. A linear relationship was observed between G6PD activity and SII and NLR. Conclusions: NLR and SII can be easily calculated in the evaluation of prolonged jaundice in G6PD deficiency has a considerable advantage. NLR and SII levels may contribute by preventing further tests for prolonged jaundice and regulating its treatment. It may be useful to form an opinion in emergencies and in early diagnostic period. Full article

Cardiovascular diseases (CVD) remain the leading cause of mortality among older adults. Early detection is critical as the prognosis for advanced-stage CVD is often poor. Consequently, non-invasive diagnostic tools that can assess hemodynamic function, particularly of the aorta, are essential. Computational fluid dynamics (CFD) has emerged as a promising method for simulating cardiovascular dynamics efficiently and cost-effectively, using increasingly accessible computational resources. This study developed a CFD model to assess the aorta geometry using tetrahedral and polyhedral meshes. A healthy aorta was modeled with mesh sizes ranging from 0.2 to 1 mm. Key hemodynamic parameters, including blood pressure waveform, pressure difference, wall shear stress (WSS), and associated wall parameters like relative residence time (RRT), oscillatory shear index (OSI), and endothelial cell activation potential (ECAP) were evaluated. The performance of the CFD simulations, focusing on accuracy and processing time, was assessed to determine clinical viability. The CFD model demonstrated clinically acceptable results, achieving over 95% accuracy while reducing simulation time by up to 54%. The entire simulation process, from image construction to the post-processing of results, was completed in under 120 min. Both mesh types (tetrahedral and polyhedral) provided reliable outputs for hemodynamic analysis. This study provides a novel demonstration of the impact of mesh type in obtaining accurate hemodynamic data, quickly and efficiently, using CFD simulations for non-invasive aortic assessments. The method is particularly beneficial for routine check-ups, offering improved diagnostics for populations with limited healthcare access or higher cardiovascular disease risk. Full article

Introduction. Pediatric traumatology is a complex field that requires a comprehensive understanding of physeal development, remodeling potential, and the ossification process in order to ensure appropriate patient treatment. The objective of this study was to assess the willingness of practicing physicians to participate in a telemedicine collaboration aimed at enhancing the exchange between the outpatient and inpatient sectors and promoting the digitalization of the pediatric sector. This is in response to the growing significance of digitalization in the medical field. Methods. A survey consisting of 15 items was sent to 800 practicing trauma surgeons, pediatric surgeons, and pediatricians within a 100 km radius of Hamburg, Germany. The survey included questions about the respondents’ professional experience and telemedicine experience, as well as inquiries about possible telemedicine collaborations. Results. The response rate was 19.3%. Less than half of the participants already used telemedicine in daily practice. In general, 75% of respondents expressed an interest in collaborating with the inpatient sector. The most common reasons for hospital referral were the need for surgery, inadequate treatment of children in practice and co-assessment. The majority were in favor of flexible communication, either via video telephony, imaging applications like or messaging applications. Conclusions. The study revealed a high level of interest in telemedicine collaboration. Information exchange should be tailored to individual needs, with practitioners requiring a versatile and personalized approach that includes imaging. Strict enforcement of data protection regulations is essential. Further research is needed to evaluate the effectiveness of telemedicine collaboration in the treatment of pediatric trauma in both hospital and outpatient settings. Full article

A hallmark of angiogenesis is the sprouting of endothelial cells. To replicate this event in vitro, biomaterial approaches can play an essential role in promoting cell migration. To study the capacity of a scaffold of fibrin (fibrinogen:thrombin mix) to support the movement of the endothelial cells, the migration area of spheroids formed with the HULEC cell line was measured. The cells were first allowed to form a spheroid using the hanging drop technique before being encapsulated in the fibrin gel. The cells’ migration area was then measured after two days of embedding in the fibrin gel. Various conditions affecting fibrin gel polymerization, such as different concentrations of fibrinogen and thrombin, were evaluated alongside rheology, porosity, and fiber thickness analysis to understand how these factors influenced cell behavior within the composite biomaterial. Data point toward thrombin’s role in governing fibrin gel polymerization; higher concentrations result in less rigid gels (loss tangent between 0.07 and 0.034) and increased cell migration (maximum concentration tested: 5 U/mL). The herein presented method allows for a more precise determination of the crosslinking conditions of fibrin gel that can be used to stimulate angiogenic sprouting. Full article

Background: Managing metabolism for optimal training, performance, and recovery in medium-to-high-level endurance runners involves enhancing energy systems through strategic nutrient intake. Optimal carbohydrate intake before, during, and after endurance running can enhance glycogen stores and maintain optimal blood glucose levels, influencing various physiological responses and adaptations, including transitory post-endurance inflammation. This randomized trial investigates the impact of a high-dose 2:1 maltodextrin–fructose supplementation to medium-to-high-level endurance runners immediately before, during, and after a 15 km run at 90% VO_2max intensity on post-exercise inflammatory stress. Methods: We evaluated inflammatory biomarkers and lipidomic profiles before the endurance tests and up to 24 h after. We focused on the effects of high-dose 2:1 maltodextrin–fructose supplementation on white blood cell count, neutrophil number, IL-6, cortisol, and CRP levels, as well as polyunsaturated fatty acids, ω-3 index, and AA/EPA ratio. Results: This supplementation significantly reduced inflammatory markers and metabolic stress. Additionally, it may enhance the post-activity increase in blood ω-3 fatty acid levels and reduce the increase in ω-6 levels, resulting in a lower trend of AA/EPA ratio at 24 h in the treated arm. Conclusions: Adequate carbohydrate supplementation may acutely mitigate inflammation during a one-hour endurance activity of moderate-to-high intensity. These effects could be beneficial for athletes engaging in frequent, high-intensity activities. Full article

Background/Objective: Out-of-hospital cardiac arrest (OHCA) poses a substantial public health concern. A collective evaluation of clinical trials is crucial for understanding systemic trends and progress within a specific research area of interest, ultimately shaping future directions. We performed a comprehensive analysis of the characteristics of trials in the adult OHCA population registered on ClinicalTrials.gov. Methods: Aided by medical subject headings (MeSH), we systematically searched the ClinicalTrials.gov database. Trends over time were assessed with the Cochran–Mantel–Haenszel test. The association between publication year and annual number was assessed with the Pearson correlation coefficient. Results: Out of 152 trials spanning the 2003–2023 period, 29.6% were observational and 70.4% were interventional. Compared with the observational trials, interventional trials were more often randomized (RCT) and achieved full publication status in 84% of cases (p = 0.03). The primary focus of interventional trials was “procedures” (43%), “devices” (23%), and “drugs” (21%). Observational studies focused on “biomarkers” (16%) and “diagnostic test” (13%) (p < 0.001). A decrement in the number of interventional trials with a sample size ≥100 patients across three temporal study points was observed. Nevertheless, published studies predominantly had a sample size ≥ 100 patients (76%), in contrast to unpublished trials (p ≤ 0.001). An increase in the number of interventional studies funded by the “academic/university” sector was also recorded. Conclusions: Clinical trials on OHCA primarily involved interventions aimed at treatment and were more often randomized, single-center, with small (<100) sample sizes, and funded by the “academic/university” sector. Full article