Search Results (1,054)

In this study, a W–polyethylene terephthalate glycol (PETG)-based 3D-printed composite was designed for medical radiation shielding, and syringe shielding components were fabricated to evaluate shielding performance and particle dispersion characteristics. Up to 70 wt% of tungsten powder was incorporated into the PETG polymer matrix to produce W–PETG filaments suitable for 3D printing. Using the fused deposition modeling (FDM) method, a 3.0 mm-thick radiation shielding cover for a 10 mL syringe was fabricated. Radiation shielding performance was assessed using a ^99mTc (200 µCi) source at distances of 30, 50, and 100 cm. While a conventional 1.0 mm Pb shield exhibited shielding efficiencies of 92.24%, 94.26%, and 95.13% at each distance, the 3.0 mm W–PETG shield demonstrated efficiencies of 70.67%, 75.64%, and 77.57%, respectively. Higher temperatures improved shielding efficiency by approximately 5.48 percentage points. When processed above 160 °C, tungsten particle clustering decreased and a more uniform dispersion was achieved, enhancing shielding performance. The interrelationship among filament fabrication parameters, particle dispersion behavior, and shielding performance of W–PETG composites was quantitatively demonstrated. The lightweight, geometric design flexibility, and compatibility with 3D-printing processes of W–PETG composites suggest strong potential as alternative materials for custom medical radiation shielding devices. Full article

This paper presents a low-cost, modular ankle–foot prosthesis that integrates an S-shaped compliant foot with a parallel spring–short-stroke actuator branch to balance energy return, impact attenuation, and rapid personalization. The design follows an FDM-oriented CAD/CAE workflow using PETG and interchangeable modules (foot, ankle unit, pylon adapter). Finite-element analyses of heel-strike, mid-stance, and toe-off load cases, supported by bench checks, show strain localization in intended flexural regions, a minimum safety factor of 15 for the housing, and peak-stress reduction after geometric refinements (increased transition radii and local ribs). The modular layout simplifies servicing and allows quick tuning of stiffness and damping without redesigning the load-bearing structure. The results indicate an engineeringly realistic path toward accessible prosthetics and provide a basis for subsequent upgrades toward semi-active control and sensor-assisted damping. Full article

Flow sensing is essential in biomedical engineering, industrial process control, and environmental monitoring. Conventional sensors, while accurate, are often constrained by high fabrication costs, complex processes, and limited design flexibility, restricting their use in disposable or rapidly customizable applications. This paper presents a novel ultra-low-cost airflow sensor fabricated entirely through fused deposition modeling 3D printing. The device employs a cantilever-based structure printed with PETg filament, followed by the deposition of a conductive ABS piezoresistive layer in a two-step process requiring no curing or post-processing. Experimental characterization reveals that the sensor operates in an ultra-low pressure range of 0.88–26.68 Pa, corresponding to flow velocities of 1.2–6.6 m/s. The sensor achieves a sensitivity of 967 Ω/Pa, a resolution of 9.27 Pa, and a detection limit of 83.27 Pa, with a total resistance change of approximately 51.5 kΩ. This kilo-ohm-scale response enables direct readout via a digital multimeter without requiring Wheatstone bridges or instrumentation amplifiers. The minimalist design, combined with sub-5 min fabrication time and material cost below $0.05, positions this sensor as an accessible platform for disposable, scalable, and resource-constrained flow monitoring applications in both biomedical and industrial contexts. Full article

Due to a number of advantages, such as the high power-to-weight ratio of the system, the possibility of easy control and the freedom of arrangement of the system components on the machine, hydrostatic drive is one of the most popular methods of machine drive. The actuators in such a system are hydraulic cylinders that convert fluid pressure energy into mechanical energy for reciprocating motion. One disadvantage of conventional actuators is their weight, so research is being conducted to make them as light as possible. Directions for this research include the use of modern engineering materials such as composites and plastics. This paper presents the possibility of using new lightweight yet strong materials for the design of a hydraulic cylinder. The base of the hydraulic cylinder were designed and subjected to FEM numerical analyses. The base was made of PET. In addition, a composite cylinder made of wound carbon fibre was subjected to numerical analyses and experimental validation. The numerical calculations were verified in experimental studies. To improve the reliability of the numerical calculations, the material parameters of the composite materials were determined experimentally instead of being taken from the manufacturer’s data sheets. The composite cylinder achieved a weight reduction of approximately 94.4% compared to a steel cylinder (95.5 g vs. 1704 g). Under an internal pressure of 20 MPa, the composite cylinder exhibited markedly higher circumferential strain (4329 μm/m) than the steel cylinder (339.6 μm/m), and axial strain was also greater (−1237 μm/m vs. −96.4 μm/m). Full article

Polyethylene terephthalate (PET) recycling technology has developed into a mature system, providing a key paradigm for the circular utilization of polyester waste. Its pathways are primarily divided into mechanical recycling and chemical recycling. Mechanical recycling converts waste PET into rPET through physical processes such as efficient sorting, deep cleaning, and melt extrusion. However, the resulting product often faces issues of decreased intrinsic viscosity and thermal oxidative degradation. Chemical recycling, particularly depolymerization techniques like saccharification, hydrolysis, and methanolysis, can reduce PET waste back to monomers. After purification, these monomers can be repolymerized into virgin-quality PET, achieving a closed-loop cycle. However, this approach faces challenges related to cost and process complexity. Against this backdrop, this paper further explores potential recycling methods for polyethylene terephthalate-1,4-cyclohexanedimethyleneterephthalate (PETG). This paper argues that the experience of PET recycling provides a crucial foundation for addressing PETG challenges but is not a direct solution. Future development directions include: developing intelligent sorting technologies, creating highly efficient selective catalysts to optimize depolymerization reactions, and other initiatives. These measures are essential for establishing an efficient recycling system for complex polyester waste. Full article

Microplastics (MPs) are recognised as emerging vectors for hydrophobic organic contaminants in aquatic environments due to their relatively large surface area and the diversity of their polymer chemistries compositions. This study investigates the sorption behaviour of two priority polycyclic aromatic hydrocarbons (PAHs), pyrene (PYR) and fluoranthene (FLU), onto six common MPs: poly(m-xylene adipamide) (PA-MXD6), high- and low-density polyethylene (HDPE, LDPE), polypropylene (PP), polyethylene terephthalate (PET), and polylactic acid (PLA). Sorption isotherms and kinetics were evaluated under simulated freshwater conditions at environmentally relevant concentrations (1–50 µg·L⁻¹). Despite the low MP concentration used (0.2 g·L⁻¹), over 80% of the initial PAH content was removed by polyolefins, and more than 50% by all other MPs. Sorption capacity was strongly dependent on particle surface area. Langmuir, Henry, and Freundlich isotherms models were fitted, with linear behaviour prevailing at low concentrations. Analysis using the Dubini–-Radushkevich model confirmed that sorption involves chemisorption contributions, mainly through π–π interactions and hydrophobic interactions (polyolefins). Mechanistically, molecular diffusion within the MP matrix was not governing the sorption process, as diffusion coefficients varied with particle size instead of polymer chemistry. Instead, sorption appears to be governed by PAH diffusion through the hydrodynamic boundary layer and subsequent retention on the MP surface. Empirically, kinetic data fitted the pseudo-second-order model, further supporting that the sorption process involves chemisorption. These findings highlight the role of MPs as vectors for PAHs in freshwater systems and their potential application in contaminant removal. Expressing sorption per unit surface area is recommended for accurate assessment. This work contributes to understanding the environmental behaviour of MPs and their implications for pollutant transport and toxicity. Full article

Determining protein requirements (PRs) for dogs remains a longstanding challenge. During growth, the rapid rate of protein deposition increases the demand for amino acids. In adult dogs, differences in overall diet digestibility and lower energy requirements of domestic dogs have led to discrepancies between the minimum crude protein (CP) value proposed by the National Research Council (NRC; 80 g of CP/kg of diet) and the 180 g of CP/kg of diet proposed by the European Pet Food Industry Federation (FEDIAF) and the Association of American Feed Control Officials (AAFCO), although most commercially available adult dog feeds offer protein levels that exceed both recommendations. In elderly dogs, physiological changes such as sarcopenia and reduced energy intake indicate a potential increase in PR, although evidence remains scarce. A similar gap exists for pregnant and lactating bitches, since most recommendations rely on extrapolations from growth studies. Classical PR recommendations were based on body weight gain and nitrogen balance (NB), methods that present important limitations. Due to this, stable isotope methods—including ¹³C-leucine, ¹⁵N-glycine, and ¹³C-phenylalanine—have emerged as precise methodological tools, enabling a detailed and dynamic assessment of whole-body protein metabolism, protein quality, and more accurate determination of PR and recommended allowance across different life stages. Full article

Pectin-derived oligosaccharides (POS) are emerging as promising functional prebiotics with growing industrial interest. This study reports a synergistic fungal pectinolytic biocatalytic system comprising endopolygalacturonase (EndoPG) and pectin methylesterase (PET11) from Aspergillus aculeatinus BCC 17849 for the controlled depolymerization of pomelo (Citrus maxima) albedo pectin. PET11-mediated demethylation increased substrate accessibility, thereby enhancing EndoPG-catalyzed hydrolysis and resulting in higher POS yields than those obtained with single-enzyme systems. The highest production of short-chain POS, comprising GalA, di-GalA, and tri-GalA (681 mg/g substrate), was achieved at an EndoPG:PET11 dosage ratio of 15:5. The resulting POS fraction significantly promoted the growth of five probiotic strains, including Lactobacilli and Bifidobacteria species, and enhanced probiotic adherence to intestinal epithelial cells. In particular, Lactobacillus acidophilus TBRC 5030 exhibited the highest adhesion level (35.24 ± 6.43%) in the presence of 2.0 mg/mL POS. Overall, this work demonstrated that enzyme-assisted demethylation coupled with targeted endo-hydrolysis enables effective tailoring of POS chain length, providing a promising biocatalytic strategy for pectin valorization into prebiotic ingredients. Full article

Background/Objectives: Fibroblast activation protein (FAP), which is abundantly expressed in cancer-associated fibroblasts (CAFs) across various epithelial malignancies, has emerged as a promising target for molecular imaging and radionuclide therapy. Although several reviews have addressed FAP-targeted diagnostics, a comprehensive synthesis integrating molecular biology, diagnostic performance, and early therapeutic development remains limited. This review summarises the current evidence on radionuclide-labelled FAP inhibitors (FAPIs), with particular emphasis on their diagnostic utility, emerging therapeutic applications, and the structural features that shape their biological behaviour. Methods: A structured literature search was conducted across PubMed, Scopus, and Web of Science, focusing on FAPI-based imaging and therapy. Results: Diagnostic studies consistently demonstrate high tumour-to-background contrast for [⁶⁸Ga]Ga and [¹⁸F]-labelled FAPI radiotracers, particularly in tumours with prominent stromal components such as pancreatic, colorectal, breast, and head and neck cancers. FAPI PET/CT often surpasses [¹⁸F]FDG in lesion conspicuity in the brain, liver, and peritoneum. Therapeutic evidence shows encouraging tumour retention and safety profiles for agents such as [¹⁷⁷Lu]Lu-FAP-2286 and [⁹⁰Y]Y-FAPI-46, while α-emitting radiotracers (e.g., [²²⁵Ac]Ac-FAPI-04) demonstrate potent antitumor effects in preclinical models. Conclusions: Radiolabelled FAPI radiotracers hold significant potential as dual diagnostic and therapeutic agents, particularly for desmoplastic tumours with high CAF content. Nonetheless, clinical evidence remains in its early stages, and substantial questions persist regarding dosimetry, intertumoral variability in FAP expression, and optimal ligand selection for therapy. Continued development of next-generation FAPI constructs, along with well-designed prospective trials, will be crucial in defining the future role of FAPI-based theranostics in oncology. Full article

Background and Clinical Significance: Isolated mediastinal lymphadenopathy is an exceptionally rare and diagnostically challenging initial manifestation of microscopic polyangiitis (MPA), often mimicking malignancy or infection. This case highlights the pivotal role of an innovative minimally invasive technique in achieving a definitive diagnosis. To the best of our knowledge, this is the first reported case of MPA diagnosed via EBUS-TMC. Case Presentation: A 55-year-old male livestock farmer from a rural area with a history of recurrent pneumonia presented with four weeks of persistent fever, significant weight loss (7 kg), myalgia, and asthenia. Physical examination revealed fever and cachexia. Notable findings included leukocytosis (17,000/μL), normocytic anemia, thrombocytosis (672,000/μL), highly elevated inflammatory markers (CRP 145 mg/L, ESR 120 mm/h), and strongly positive MPO-ANCA (>134 U/mL). Serological testing was significant for IgG antibodies against Coxiella burnetii (Phase I 1:64, Phase II 1:256). PET-CT imaging demonstrated hypermetabolic bilateral hilar and mediastinal lymphadenopathy. Diagnostic challenges included overlapping serological findings suggestive of past Coxiella burnetii exposure. Endobronchial ultrasound–guided transbronchial mediastinal cryobiopsy (EBUS-TMC) of a subcarinal lymph node was performed, providing a high-quality sample that revealed neutrophilic small-vessel vasculitis with fibrinoid necrosis, definitive for MPA. Immunosuppressive therapy with high-dose corticosteroids and rituximab (1000 mg on days 1 and 15) was initiated, leading to the complete resolution of all constitutional symptoms. Conclusions: This case illustrates that EBUS-TMC is a safe and highly effective diagnostic tool for obtaining critical histological evidence in systemic vasculitides with atypical presentations. This technique should be considered in the diagnostic algorithm for unexplained mediastinal lymphadenopathy to avoid more invasive surgical procedures. Full article

Fiber Metal Laminates (FML), produced in both monolithic and sandwich configurations with glass-, basalt- and carbon-reinforced composites, were investigated for application in fire-resistant lithium battery boxes. Different resins, including recyclable and bio-based systems, were tested to improve sustainability; cores of recycled PET (RPET, 150 g/dm³, 10 mm) were considered. The study focused on the effect of core introduction on mechanical performance, with the dual goal of reducing weight and achieving stiffness values compliant with automotive OEM standards for lithium battery housings. Results demonstrated that sandwich structures improved stiffness up to 12-fold compared to monolithic laminates, while preserving the corrosion resistance of the outer aluminium layer and the flexural strength of the laminates after 670 h of Neutral Salt Spray (NSS) exposure. Full article

This study evaluated 65 commercially available pet feed samples, including 33 cat feeds and 32 dog feeds (dry and wet formulations), for the presence of organic contaminants. These included mycotoxins, pesticides, pharmaceutical residues/veterinary drugs, and plant-based bioactive compounds. A suspect screening strategy was employed using QuEChERS extraction followed by LC-LTQ/Orbitrap HRMS analysis. A total of 29 compounds were tentatively identified within 186 detections. In total, 76.9% of the samples were contaminated with mycotoxins. Aflatoxins (B1, B2, G1, and G2), T2 toxins, and HT2 toxins were dominant, with Aflatoxin B1 occurring in 33.8% of the samples and exhibiting a higher prevalence in dry feeds than in wet feeds. Pesticides were present in 72.0% of the dry formulations, including aclonifen and pirimiphos-methyl, but were present in only 11% of the wet formulations. Plant-based bioactive compounds, including phytoestrogens, were identified in 51% of the samples, highlighting toxicologically relevant candidates that merit prioritization for targeted confirmation, particularly in cat feeds. Pharmaceuticals were found in 23.8% of dry feeds (sparfloxacin and fumagillin). Overall, the HRMS-based, standard-free suspect screening workflow provides an early-warning overview of multi-class co-occurrence patterns in complex pet feed matrices and supports the prioritization of candidates for subsequent confirmatory analysis. Full article

Directly printed aligners represent a promising alternative to conventional thermoformed aligners. The aim of this in vitro study was to compare the effects of water on the mechanical properties of directly printed aligners with those of conventionally manufactured thermoformed PET-G foils. Dental LT Clear V2 (LT), V Print Splint Comfort (VP), and TC-85 DAC (TC) were examined. Biolon (BL), a conventional PET-G material, served as the thermoplastic reference material. All samples were tested before and after 14 days of water storage at 37 °C. We performed a three-point bending test and an indentation test, and examined changes in the abrasion resistance and hygroscopic volume. The resistance of all printed specimens decreased significantly after water storage. VP and TC were less resilient than BL overall. LT and BL exhibited the lowest indentation creep (BL: 0.08 ± 0.01, LT: 0.13 ± 0.02, VP: 0.21 ± 0.02, TC: 0.24 ± 0.02). Furthermore, the abrasion of LT (0.72 ± 0.21 mm³) was significantly lower than that of BL (1.12 ± 0.37 mm³). In conclusion, the water sorption of the printed test specimens had a significant influence on the mechanical properties, with a reduction in the flexural modulus, Martens hardness, and plastic hardness. Full article

Herein, a high-performance Ta₂O₅/AgNPs composite Surface-Enhanced Raman Scattering (SERS) substrate is engineered for highly sensitive detection of microplastics. Through morphology modulation and band-gap engineering, the semiconductor Ta₂O₅ is structured into spheres and composited with silver nanoparticles (AgNPs), facilitating efficient charge transfer and localized surface plasmon resonance (LSPR). This architecture integrates electromagnetic (EM) and chemical (CM) enhancement mechanisms, achieving an ultra-low detection limit of 10⁻¹³ M for rhodamine 6G (R6G) with excellent linearity. Furthermore, the three-dimensional “pseudo-Neuston” network structure exhibits superior capture capability for microplastics (PS, PET, PMMA). To address spectral interference in simulated complex environments, a multi-scale deep-learning model combining wavelet transform, Convolutional Neural Networks (CNN), and Transformers is proposed. This model achieves a classification accuracy of 98.7% under high-noise conditions, significantly outperforming traditional machine learning methods. This work presents a robust strategy for environmental monitoring, offering a novel solution for precise risk assessment of microplastic pollution. Full article

Endometriosis is a highly prevalent, chronic gynecological disorder characterized by the ectopic presence of endometrial-like tissue, driving significant morbidity and chronic pelvic pain. Pathologically, it is increasingly recognized as a fibro-inflammatory condition involving extensive tissue remodeling and fibrosis. Current conventional imaging modalities, including ultrasound and MRI, are primarily morphological, while standard molecular imaging using Positron Emission Tomography (PET) tracers has shown limited diagnostic utility. [¹⁸F]Fluorodeoxyglucose (FDG) suffers from high physiological uptake in pelvic organs and inconsistent detection of lesions. Receptor-based tracers like [⁶⁸Ga]Ga-DOTATATE have demonstrated uncertain efficacy. In contrast, radiopharmaceuticals targeting the Fibroblast Activation Protein (FAP) offer a promising molecular approach. FAP is specifically overexpressed by activated fibroblasts present in the stroma of endometriotic lesions, correlating significantly with tissue fibrosis (collagen content) and local immune infiltration (e.g., CD68 macrophages). This comprehensive review analyzes the landscape of radiopharmaceuticals for endometriosis imaging, contrasting the specific limitations of traditional metabolic and receptor agents with the molecular rationale and emerging evidence supporting the use of FAP Inhibitors (FAPI), positioning them as crucial, non-invasive tools for the future diagnosis and management of this challenging disease. Full article