Science Progress最新文献

In order to optimize the overall form of electromagnetic scattering in two-dimensional dielectric media, this work offers a frequency-domain boundary element method based on isogeometric analysis. The Isogeometric boundary element method (IGABEM) is used to guarantee geometric correctness during optimization and prevent over-refinement of the mesh. Non-uniform rational B-splines are used to discretize the boundary integrals of the model, enabling rapid numerical computation while ensuring high accuracy. Furthermore, as an alternative model for electromagnetic scattering shape optimization issues, a gray wolf optimizer-based back-propagation neural network (GWO-ANN) is created, with radar cross-section (RCS) as the objective function. Finally, the GWO-ANN is used as a surrogate model for shape optimization in multi-frequency electromagnetic scattering problems with the RCS as the objective function. In computational examples, this algorithm efficiently and accurately solves electromagnetic scattering problems under multiple frequencies.

Understanding aerodynamic entrainment, a critical process in wind-blown sand dynamics, remains challenging due to the difficulty of isolating it from other mechanisms, such as impact entrainment. Aerodynamic entrainment initiates the movement of surface particles, influencing large-scale processes like sediment transport and dune formation. Previous studies focused on average aerodynamic shear stress to estimate entrainment, but the role of impulse events, which cause significant shear stress fluctuations, remains under-explored. We used 12 hot-film shear sensors to measure the spatiotemporal distribution of aerodynamic shear stress during wind-blown sand flow development. We identified impulse events exceeding the entrainment threshold and analyzed their intensity, classifying particle movement as rocking, rolling, or saltation. Results indicate that after a 2-m fetch, sediment mass flux stabilizes, with aerodynamic shear stress decreasing to 78% of the entrainment threshold. We identified key trends, including the stabilization of rocking events beyond x = 4.5 m and a significant decrease in saltation frequency, indicating fully developed wind-blown sand flow. Impulse characteristics stabilize at a greater distance (4.5 m) than sediment transport (2 m) because turbulent airflow evolves more slowly. Our findings show that impulse events significantly influence aerodynamic entrainment. These insights enhance understanding of sediment transport dynamics and improve modeling of sand dune movement.

Sinonasal inverted papilloma (SNIP) is less malignant and usually occur in the maxillary sinus. However, cases invading the pterygopalatine fossa are extremely rare. In this article, we describe a rare case of a man in his early 60s who presented with left nasal congestion, headache, epistaxis, and facial numbness. The patient underwent a comprehensive treatment primarily based on surgery. Nasal endoscopy showed that the mass had invaded the left infratemporal fossa laterally and was poorly separated from the internal maxillary artery, which increased the complexity and difficulty of the surgery. In addition, the patient had previously undergone nasal cavity surgery, which made the surgery more challenging. In order to reduce the risk of recurrence, we exposed the infratemporal fossa region under nasal endoscopic guidance with a combined labial and gingival incision, and completely removed the tumor base and tumor margins. There were no postoperative complications and no recurrence was observed during the 2-year follow-up period.

Manufacturing industries involve both business processes and complex manufacturing processes. Predictive process monitoring techniques are effective for managing process executions by making multi-perspective real-time predictions, preventing issues such as delivery delays. Conventional predictive process monitoring for business processes focuses on predicting the next activity, next event time, and remaining time using single-task learning, which is costly and complex. For complex manufacturing processes, predictive process monitoring primarily aims to predict the remaining time, that is, product cycle time. However, single-task learning methods fail to capture all the variations within the historical process executions. To address them, we propose the multi-gate mixture of transformer-based experts framework, which leverages a transformer network within the multi-gate mixture-of-experts multi-task learning architecture to extract sequential features and employs gated expert networks to model task commonalities and differences. Empirical results demonstrate that multi-gate mixture of transformer-based experts outperforms three alternative architectures across five real-life event logs, highlighting its generalization, effectiveness, and efficiency in predictive process monitoring.

In head and neck, adenoid cystic carcinoma (ACC) is a rare malignant tumor. ACC mainly generated from minor salivary glands, especially in the palate. We report an extremely rare case of ACC generating in the left palatine tonsil. A 50-year-old woman with foreign body sensation in the pharynx for 6-month was admitted to our hospital. Physical examination revealed a dark red mass in the soft palate near the upper pole of the left tonsil. Preoperative imaging examinations indicated a low-density mass in the left tonsillar area on the CT plain scan, which was a hyperintense mass at the anterior superior pole of the left tonsil on T2-weighted MRI. Complete surgical resection of the mass together with the left palatine tonsil was conducted under general anesthesia. The diagnosis of ACC was established based on histopathology and immunohistochemistry results. Then, postoperative radiotherapy of 60 Gy was administered. During regular medical follow-up for 12 months, no local recurrence was observed. Complete surgical resection, with or without postoperative radiotherapy is generally acknowledged as the standard of care for ACC. Despite the extremely low incidence in palatine tonsil, clinicians should consider the differential diagnosis of ACC.

This study aims to explore the feasibility of replacing traditional components, such as Portland cement, river sand and tap water with sugarcane bagasse ash (SCBA), polypropylene (PP) fibers, and sea sand-seawater (SSSW) in lightweight foamed concrete (LWFC) production. SCBA was used in the range from 0 to 15% as cement replacement, and PP fibers were used with dosage from 0% to 1% by volume of LWFC. Meanwhile, SSSW was used to completely replace river sand and tap water. The investigation delves into the fundamental physico-mechanical properties of LWFC, encompassing compressive strength, splitting tensile strength, and water absorption. The incorporation of SCBA initially displayed a negative impact on the early strength of LWFC, which was mitigated by the favorable effects of PP fibers and SSSW. At later ages, SCBA contributed to increased compressive strength, yet a threshold level was identified beyond which excessive SCBA adversely affected this strength property. Furthermore, statistical regression analyses were employed to interpret test results, revealing promising findings. A regression model was proposed to predict splitting tensile strength LWFC from corresponding compressive strength, yielding an R² of 0.74. Lastly, utilizing SCBA as cement replacement and incorporating SSSW into LWFC production resulted in reduced water absorption.

With the growing number of tram operation lines, tram-related traffic incidents, particularly train collisions, have become a major issue. Therefore, the ability to identify foreign objects on a track is critical to tram operational safety. Accurately identifying the rail edge is a critical technology for recognizing the track area and providing early warnings of potential threats. Therefore, this study proposes a self-adaptive rail-edge detection algorithm that uses mathematical morphology and computer vision technology to accurately extract rail edges. The performance of the proposed algorithm was compared to that of existing algorithms, including the Canny algorithm and two other methods described in publication. Three scenes in the level crossing area of trams were considered as the research objects, and the effects of two types of noise in the image were explored in terms of the investigated using mean square error (MSE), peak signal-to-noise ratio (PSNR), and computational time. The results showed that the proposed model exhibited strong robustness for different scenes, particularly in the presence of noise. This suggests that the proposed algorithm could be used in early warning systems of trams to identify rail edges.

With the increasing speed of high-speed train, it is more and more difficult to reduce the vibration and noise inside the train. The floor of the train, as a carriage component in direct contact with passengers, is of great significance to improve its vibration and sound isolation performance to ensure the comfort of passengers. In this article, a floor vibration isolator with quasi-zero stiffness is designed based on the dimensional parameters of the traditional floor vibration isolator, and the vibration isolation performance is analyzed by the finite element model of the floor vibration isolator from the static and dynamics aspects, respectively. The load-displacement curves of the floor vibration isolator are obtained through static simulation calculations, and the dynamic analysis of the floor vibration isolator is carried out by simulation methods, which verifies the low-frequency vibration isolation performance of the floor vibration isolator under different working conditions, and the vibration isolator has a good prospect for development.

Objectives: The most recent version of ClinVar was utilized to filter variants of the MC4R gene based on location, condition, and clinical significance with the goal of obtaining benign and disease-associated variants of the MC4R gene. MC4R gene variants can lead to dysregulation of energy expenditure and appetite control, which prompted this study to delineate the distinctive features of MC4R gene variants submitted to the ClinVar repository regarding their association with obesity and related phenotypes.

Method: A thorough search was conducted in the ClinVar repository for clinically significant MC4R variants through the utilization of the gene name MC4R[gene] and MeSH terms "MC4R[gene]" and "single gene"[properties]" in the search box. Leading to the identification of clinically significant genetic variants associated with obesity.

Results: Utilizing the ClinVar clinical significance ranking system, the MC4R variants were categorized into six groups based on ClinVar/ClinGen's ranking system: pathogenic (P), likely pathogenic (LP), variant of uncertain significance (VUS), benign (B), likely benign (LB), and conflicting classifications (CC). A total of 103 pathogenic variants were observed. These variants have different clinical significance that are associated with monogenic obesity, monogenic diabetes, and body mass index quantitative traits. It was observed that over 80% of the mutations were single nucleotide variants, with nearly half being missense mutations spread throughout the topological and transmembrane domains. Furthermore, TM7 had the highest number of single nucleotide missense mutations.

Conclusion: Further analysis of the relationships between monogenic obesity and diabetes requires additional investigation to discover the underlying causes of these conditions. The study findings imply that mutations in MC4R's topological and transmembrane regions may significantly influence receptor activation and signaling. As more MC4R variants are discovered and their correlation with obesity is established, there is potential to definitively establish a strong connection between MC4R pathogenic variants and the development of obesity.

Venereal syphilis, caused by Treponema pallidum, is a major global health problem. Untreated latent syphilis can progress to tertiary syphilis, often leading to severe complications such as cardiac involvement, particularly syphilitic aortitis, which may manifest decades after the initial infection. We present a case of a 46-year-old woman who developed an ascending aortic aneurysm and severe aortic valve insufficiency due to late-stage syphilis. She presented with bilateral lower limb edema, intermittent chest pain, decreased functional capacity, and dyspnea, ultimately requiring hospitalization for cardiogenic shock. Diagnostic imaging revealed significant aortic valve damage and aneurysmal dilation of the ascending aorta, while serological tests confirmed tertiary cardiovascular syphilis. Surgical intervention involved the reconstruction of the ascending aorta and replacement of the aortic valve with a bioprosthetic valve. Histopathological analysis indicated chronic endocarditis. Postoperative management included intensive care support and antibiotic treatment. The patient demonstrated satisfactory recovery, with no further complications reported at the 3-month follow-up.