Search Results (4,211)

DC motors are widely used in mechatronic systems; however, their performance degrades significantly in the presence of nonlinear mechanical loads, parameter variations and sensing uncertainties. This paper proposes three control strategies (i.e., PID, optimal, and hybrid controllers) for discrete-time DC motor systems to overcome the disturbances caused by nonlinear mechanical loads and parameter variations. Optimal control of nonlinear discrete-time systems is formally characterized by the Hamilton–Jacobi–Bellman (HJB) equation, whose analytical solution is generally intractable. To address this challenge, a learning-based optimal control strategy based on the Heuristic Dynamic Programming (HDP) framework is developed to approximate the HJB equation, supported by a formal convergence proof. For that purpose, Neural Networks (NNs) are employed to approximate both the cost function and the optimal control policy, enabling near-optimal performance with manageable computational complexity. Although the resulting optimal control achieves fast convergence, it may introduce overshoot and steady-state offset under nonlinear disturbances. To address this limitation, a hybrid control framework is proposed, where nonlinear optimal corrections are integrated with the robustness and adaptability of Proportional–Integral–Derivative (PID) control through error-dependent gating and gain-scheduling mechanisms. A structured evaluation framework is conducted, including nominal analysis, motor-parameter stress testing across nine nonlinear scenarios, controller-design sensitivity analysis, and stochastic measurement-noise assessment under filtered sensing conditions. Results demonstrate that the hybrid controller preserves transient speeds within 5–10% of the optimal controller while effectively eliminating overshoot and steady-state offset under nominal conditions. The hybrid design reduces the accumulated tracking error by more than 95% compared to the optimal controller, while incurring only negligible additional control effort. Under aggressive supply-sag disturbances, the hybrid controller significantly limits peak deviation and reduces accumulated tracking error by over 90%, while maintaining comparable control cost. Overall, the hybrid framework provides a convergence-proven and practically deployable control solution that combines near-optimal convergence speed with robust, overshoot-free performance for intelligent motion-control and robotics applications. Full article

Background/Objectives: Chimpanzee adenoviral-vectored vaccines have proven to be both safe and effective, with a manufacturing and distribution pipeline capable of rapid global supply, as demonstrated during the COVID-19 pandemic. Yellow fever is a mosquito-borne viral hemorrhagic disease endemic in parts of Africa and Latin America, and although an effective live attenuated vaccine exists, its use is limited by safety and eligibility restrictions. Moreover, large outbreaks continue to expose critical challenges, such as an insufficient vaccine supply, reliance on fractional dosing, and slow and difficult-to-scale manufacturing processes. Here, we report the design, development and in vivo immunogenicity of multiple yellow fever virus (YFV) antigen constructs based on the pre-membrane (prM) and envelope (E) proteins—with or without the transmembrane domain (TM or ΔTM)—delivered using the ChAdOx1 adenoviral vector. Methods: Four ChAdOx1 YF vaccines were developed, and immunogenicity was evaluated. The efficacy of the full-length YF envelope vaccine was also tested in Balb/c mice. Results/Conclusions: In contrast to previously described orthoflavivirus vaccines on the same platform, the full-length antigen elicited superior immunogenicity and conferred protection against intracranial challenge with the YF17D virus in mice. Notably, this protection was comparable to that induced by the licensed YF17D vaccine, highlighting the promise of this platform as a next-generation yellow fever vaccine candidate. Full article

Syphilis remains a global public health concern, with maternal infection posing a substantial risk for congenital syphilis, a preventable condition associated with severe morbidity and mortality. Penicillin, particularly benzathine penicillin G, remains the cornerstone of treatment and the only therapy with proven efficacy in preventing vertical transmission during pregnancy. However, recurrent global shortages, limited manufacturing capacity, mislabeling of penicillin allergy, and the absence of validated alternative regimens for pregnant women and neonates threaten progress toward elimination goals. This review summarizes current evidence on the treatment of syphilis in pregnancy and congenital syphilis, highlighting the established maternal and neonatal regimens, diagnostic and therapeutic challenges, and clinical consequences of delayed or inadequate treatment. We examine the scope and drivers of benzathine penicillin G shortages, the overestimation of penicillin allergy and its impact on care, and the role of neonatal management when maternal therapy is suboptimal. Emerging data on alternative antimicrobial agents, including cephalosporins, tetracyclines, lipoglycopeptides, and novel compounds are discussed considering recent advances in Treponema pallidum culture and susceptibility testing. While several non-penicillin agents show promise for non-pregnant populations, robust evidence supporting their use during pregnancy and for the prevention of congenital syphilis is lacking. Addressing these gaps through coordinated supply chain strategies, guideline harmonization, and targeted clinical research is essential to ensure resilient and equitable syphilis control and advance global efforts toward the elimination of congenital syphilis. Full article

Familial Mediterranean fever (FMF) is a monogenic autoinflammatory disease in which renal involvement is a major determinant of prognosis and is classically dominated by amyloid A (AA) amyloidosis. Non-amyloid renal manifestations are uncommon and poorly characterized. We report a case of clinically overt FMF associated with anti-phospholipase A2 receptor (PLA2R) antibody-positive membranous nephropathy (MN). A 46-year-old man with recurrent febrile episodes fulfilling Tel Hashomer criteria for FMF developed progressive proteinuria with detectable anti-PLA2R antibodies. Genetic testing identified a heterozygous missense MEFV variant in exon 10 (p.Lys695Arg), a mutation with variable penetrance and conflicting pathogenic classification. Kidney biopsy demonstrated PLA2R-positive MN, excluding amyloidosis. After initial conservative management, the patient progressed to nephrotic syndrome complicated by renal vein thrombosis, requiring immunosuppressive therapy according to the Ponticelli regimen in addition to colchicine and anticoagulation, resulting in clinical and immunological remission. In parallel, we performed a systematic review of the literature, identifying only isolated reports of biopsy-proven MN in FMF patients. This case highlights the diagnostic importance of kidney biopsy in FMF patients with proteinuria and illustrates that immune-mediated glomerular disease may occur even in association with non-founder or variably penetrant MEFV mutations, requiring disease-specific management beyond standard autoinflammatory control. Full article

The identification of calcareous foraminifera and nannofossils in archaeological ceramics (tiles and bricks from the Archaic to Roman ages) of Naxos and Taormina (Sicily) has, along with other evidence and archaeometric analyses, addressed aspects of technology and raw material source areas. Microfossils, like the other aplastic inclusions, help to interpret ceramic pastes. This paper provides, for northeastern Sicily, a contribution demonstrating the importance of an integrated approach in the study of archaeological ceramics; micropaleontological analysis supports mineralogical, petrographic and chemical data to constrain interpretations of provenance and technology. The preservation of foraminifera calcitic tests and coccoliths is an additional key to identifying errors, failures and strategies during the ancient ceramic firing process. Comparisons with the micropaleontological content of locally outcropping clay deposits have allowed for the unambiguous identification of the clay sources used for ancient ceramic production in the region. Full article

Asbestos-containing materials (ACMs) are among the most common types of hazardous building materials. Usually, ACMs are identified by laboratory methods, which can slow down and complicate the processes of demolition and refurbishment of old buildings. The hypothesis applied in this study is that ACMs, both in friable and non-friable forms, can be reliably identified in situ using a handheld Raman spectrometer (HHRS). A HHRS equipped with two temperature-controlled diode lasers (785 nm and 852 nm) was used. Two groups of ACMs were examined: one, consisting of ACMs with a known type of asbestos, previously determined by standardised tests used for the HHRS method’s validation, and the second, consisting of presumed ACMs, where HHRS was used for the identification of asbestos. Additional testing according to ISO 22262-1 was applied. The impact of several factors on the asbestos identification was evaluated. The results confirm that the identification by HHRS of all main types of asbestos minerals is possible with a certain level of probability, regardless of whether the fibres are in an unbound form (fabrics, ropes, wools) or bound within cementitious or polymer composites. Some processing (scaling, smoothing) of the reference spectra should be applied to increase the percentage of asbestos minerals’ identification. In conclusion, it has been proven that the majority of ACM in buildings may be identified in situ by HHRS in a rapid manner, thus accelerating the pre-demolition/pre-renovation audit (PDA/PRA), avoiding risks to demolition/refurbishment workers’ health due to asbestos unawareness, as well as preventing the contamination of other CDW and environmental pollution. Full article

To select and breed superior varieties of Dendrobium officinale with high quality and strong resistance to adverse conditions, a systematic selection process was employed to screen for outstanding strains, complemented by tissue culture for seed propagation. Following screening and self-purification, a new variety, ‘Tiefeng No.1’, was developed. Between 2019 and 2023, a comprehensive assessment of its characteristics, regional product ratio tests, and productivity research was meticulously conducted. The results indicated that the new variety of Dendrobium officinale is stable and of excellent quality. The polysaccharide content ranged from 44.35% to 58.55%, and the mannose content varied from 14.03% to 22.38%, both of which meet the standards set by the Chinese Pharmacopoeia (2020). The anthocyanidin content was measured at 94.76 to 115.43 μg/g, which is double that of the Yueqing landraces. It exhibits good frost resistance and disease resistance. Through production verification and demonstration, ‘Tiefeng No.1’ has proven to possess excellent quality and high yield, showcasing significant potential for promotion in the primary growing regions. Full article

To address the strongly coupled and highly nonlinear optimization problems arising from the increasing system complexity, optimization objectives, and variable dimensions in practical engineering applications, this paper proposes a multi-strategy enhanced NSGA-III algorithm (MSNSGA-III) by introducing K-means clustering, an adaptive hybrid operator, and an assistant evolutionary population strategy on the basis of the NSGA-III algorithm. This algorithm overcomes the performance limitations of the original algorithm in large-scale search with multiple variables. By employing the DTLZ test functions with different variable dimensions and conducting comparisons with six other representative algorithms, the proposed algorithm is proven to have strong competitiveness in terms of diversity and convergence speed. To reflect the superiority of the algorithm in practical applications, this paper establishes a variable-thickness optimization model for the morphing leading edge. By adopting the spline curve-based optimization variable control strategy and the MSNSGA-III algorithm, the optimal thickness distribution of the leading edge skin is obtained. The results show that, compared with the leading edge with a fixed skin thickness of 1.5 mm, the optimized variable thickness skin leading edge achieves 43.6% improvement in shape maintaining accuracy, 40.9% improvement in deformation accuracy, and 17.5% reduction in driving force. Full article

Background/Objectives: The aim was to assess whether a machine learning (ML) algorithm could empower the ability of ultrasound (US) integrated with shear-wave elastography (SWE) to preoperatively define the ALN status in breast cancer (BC). Methods: Patients with at least one histologically proven BC lesion, who underwent preoperative breast US and SWE were retrospectively enrolled. BC lesions were segmented on US and SWE images by three different operators and radiomics features were extracted. A multi-step US and SWE feature selection was performed. A Simple Logistic ML classifier was applied to the dataset to predict the ALN status, its performance assessed through the AUC and Matthews Correlation Coefficient (MCC). The performance of the ML classifier was compared to that of an expert radiologist, who evaluated the US B-mode lymph-node features included in the test set. Results: A total of 133 BC lesions were included and divided into a training set, composed of 89 BC lesions (ALN−: 52; ALN+: 37), and a test set, including 44 BC lesions (ALN−: 24; ALN+: 20). Eight features out of the 1098 radiomics features extracted from US and SWE images were selected to build the predictive model. Simple Logistic classifier showed AUC of 0.685 and 0.677, MCC of 0.387 and 0.375 in the training and test set, respectively. The performance of the expert radiologist was higher than that of the ML classifier (AUC = 0.817), but not significantly different (p = 0.481). Conclusions: The inclusion of SWE-derived radiomics features could aid in the preoperative assessment of ALN status in BC using an ML approach. Full article

Pulmonary histoplasmosis is often misdiagnosed as or coinfected with pulmonary tuberculosis (TB). This study aims to analyze the misdiagnosis or co-occurrence of published cases of pulmonary TB and pulmonary histoplasmosis. Cases of histoplasmosis with dissemination were excluded, as it affects other organs. Systematic research was conducted using PubMed, EBSCOhost, ProQuest, BioRxiv, and MedRxiv databases. Twenty-seven articles were included, covering a total of 51 cases. Males were predominantly affected, with a median age of 54 years. Exposure to caves and farming occupations were identified as the primary sources of infection (61.9%). The most common clinical symptoms were fever (80%) and cough (82.5%). Laboratory tests revealed culture positivity in 77.1% of cases, with sputum being the most frequently used specimens. In proven pulmonary histoplasmosis, antibody tests were positive in 18 out of 24 cases. Chest X-rays commonly showed cavities, infiltrates, and nodules, with an increase in nodular pattern in recent cases. The number of pulmonary nodules detected was higher on chest computed tomography (CT). Radiologic abnormality could occur in any lung region. This review suggests the potential for misdiagnosis and/or coinfection of pulmonary histoplasmosis and pulmonary TB. The combination of clinical suspicion, radiological findings, antibody and/or antigen testing could improve the diagnosis of pulmonary histoplasmosis. Full article

A Ti6Al4V alloy fabrication via laser powder bed fusion (L-PBF) leads to the formation of coarse columnar β grains that give rise to anisotropic mechanical properties and inadequate strength. Incorporating the rare-earth oxide, yttrium oxide (Y₂O₃), has proven an effective strategy in enhancing the mechanical performance of Ti6Al4V alloys. Nevertheless, the critical Y₂O₃ content required to achieve an optimal strength–ductility balance in L-PBF Ti6Al4V has not been systematically determined. To address these critical gaps, this study, for the first time, systematically investigates the effect of various Y₂O₃ contents on the microstructural evolution and mechanical properties of Ti6Al4V alloys fabricated via L-PBF. The results demonstrate that a Y₂O₃ addition of 0.2 wt.% produces β grains and α phases with average sizes of 61.6 and 7.6 μm, respectively. Transmission electron microscopy observations reveal that Y₂O₃ nanoparticles, together with elemental Y nanoparticles formed by reduction, are distributed both within the α-Ti matrix and along phase boundaries. This distribution effectively reinforces grain boundaries and promotes heterogeneous nucleation, thereby refining the microstructure. Mechanical property tests indicate that the alloy strength significantly improves as the Y₂O₃ content increases. Specifically, the alloy with 0.2 wt.%Y₂O₃ exhibits a tensile strength of 1106 MPa, a yield strength of 1074 MPa, and an elongation of 10.7%. This study proposes an innovative rare-earth strengthening method for refining the microstructure of L-PBF-fabricated titanium alloys and comprehensively enhancing their mechanical properties. Full article

Background/Objectives: The purpose of this study was to investigate the laser removal of implant-supported ceramic single crowns, focusing on their efficiency and the potential reusability of the removed restorations. Methods: Sixty single crowns made of lithium disilicate were adhesively bonded to prefabricated titanium abutments in a total of six test series (n = 10). The test series were divided according to the different spacer settings of the crowns (90 µm, 120 µm, 150 µm) and the taper of the abutments (4°, 6°). After seven days of storage in distilled water, the single crowns were removed using an erbium-doped yttrium aluminium garnet (Er:YAG) laser. The number of laser pulses needed and the time required to remove the crowns were recorded. This was followed by a micro- and macroscopic score evaluation of the crowns using a fluorescent penetration method. Results: Laser removal of all sixty crowns was successfully performed. Using a taper of 6° and a spacer of 150 µm, the crowns were removed with significantly fewer pulses (61.40 (±36.78)). The taper and spacer had a significant effect on both the microscopic (p = 0.040) and macroscopic (p = 0.035) fracture patterns. Based on the final score of the fracture analysis, 44 of the 60 crowns could be classified as potentially reusable. The remaining 16 crowns failed due to purely macroscopic (7), purely microscopic (6), and combined microscopic and macroscopic (3) fracture behavior. Conclusions: Based on the results of this study, increasing the size of the taper and spacer has proven beneficial for laser removal in terms of time efficiency and non-destructive removal of crowns. Full article

The ultraviolet (UV) copolymers of two monomers, one methacrylic and the other vinyl monomer (styrene, S) were prepared. As methacrylic monomers, citronellyl methacrylate (CM) or geranyl methacrylate (GM) were used. The preparation was proven to contain high solvent- and chemical-resistant copolymers due to their cross-linked structure with the conversion degree of the double bonds above 0.92 for poly(citronellyl methacrylate)/polystyrene (PCM/PS) and above 0.85 for poly(geranyl methacrylate)/polystyrene (PGM/PS) copolymers. The obtained copolymers showed only one glass transition temperature (T_g). Depending on the structure and amount of the used methacrylic monomer, the T_g values were from 0.4 °C to −15.2 °C for PCM/PS copolymers and from −23.2 °C to −50.5 °C for PGM/PS copolymers. The thermogravimetric analysis (TG/DTG) showed a higher thermal stability for PCM/PS (148–187 °C) than for PGM/PS copolymers (119–159 °C) in inert and oxidative atmospheres. The simultaneous thermogravimetric analysis coupled with Fourier Transform Infrared spectroscopy (TG/FTIR) showed that the pyrolysis and oxidative decomposition of the tested copolymers took place according to the radical mechanism. This led to receiving a mixture of low molecular mass organic molecules containing saturated and unsaturated fragments, carbonyl groups, aromatic fragments as well as to CO, CO₂ and H₂O. This indicated the depolymerization process (inert) and further oxidation processes of the initially formed volatiles and/or residues in oxidative conditions. Full article

The seemingly endless expanse of the sky might suggest that it could support a large volume of aerial traffic with minimal risk of collisions. However, mid-air collisions do occur and are a significant concern for aviation safety. Pilots are trained in scanning the sky for other aircraft and maneuvering to avoid such accidents, which is known as the basic see-and-avoid principle. While this method has proven effective, it is not infallible because human vision has limitations, and pilot performance can be affected by fatigue or distraction. Despite progress in electronic conspicuity (EC) systems, which effectively increases the visibility of aircraft to other airspace users, their utility as collision avoidance systems remains limited. This is because they are recommended but not mandatory in uncontrolled airspace, where most mid-air accidents occur, so other aircraft may not mount a compatible device or have it inactive. In addition, their use carries some risks, such as causing pilots to over-focus on them. In response to these concerns, this paper presents evidence on the utility of using an optical flow-based obstacle detection system that can complement the pilot and electronic visibility in collision avoidance, but that, unlike pilots, neither gets tired like the pilot does nor depends on whether other aircraft have mounted devices, such as EC devices. The current investigation demonstrates that the proposed optical flow-based obstacle detection system meets or exceeds the critical minimum time required for pilots to detect and react to flying obstacles (12.5 s) using a mid-air collision simulator in various test environments. Full article

Human-driven soil erosion is a signal of the widely debated “Anthropocene”. There is widespread controversy regarding the time consistency and time transgression of human-driven soil erosion in the Late Holocene. In this study, three well-dated cores, B10, B14 and W20 from west to east, spanning the past 4–6 ka from the Pearl River Estuary (PRE) shelf, southern China, were selected for elemental tests. Principal component analysis divides the elements into four components. The first principal component (PC1) includes TFe₂O₃, Al₂O₃, V, Cs, Rb, Ga, TiO₂, K₂O, Ta, Nb, MnO, Th, LOI, and Cl, being the proxy for fine-grained terrigenous input and watershed soil erosion. The PC1 variations in B10 and B14 reveal that erosion enhanced at ~2.2 ka BP, and less erosion occurred at ~1.5 ka BP but has intensified since ~1.2 ka BP, which is consistent with the simulated cropland area of the Pearl River Basin and lake records in the upper West River, southwestern China. However, the records from the W20 reveal a continuous increase in terrestrial input since 2.2 ka BP, which is consistent with the soil erosion changes recorded by the South China coast lakes at its provenance region. Hence, differences in the initial age of the signals of human activities were revealed in the PRE shelf system. Our study not only reveals the time transgression of the “Anthropocene” boundary but also updates the sediment source-to-sink model of the PRE shelf system. Full article