Search Results (639)

(1) Background: Bio-based plastics are an alternative for commonly used petroleum-based plastics, and their production will increase in the coming decades. In this work, two innovative bio-based plastics, i.e., polylactide-based (PLA-based) and polyhydroxybutyrate-based (PHBV-based), were studied with regard to their effect on the growth of higher plants (Sorghum saccharatum, Sinapsis alba) in the soil environment. (2) Methods: The experiments were conducted in pots filled with the Organisation for Economic Co-operation and Development (OECD) reference soil with or without one of the bioplastics at concentrations from 0.1% w/w to 12.5% w/w. This study is one of few works in which soil instead of another medium (e.g., deionised water) was used for the evaluation of the impact of microplastics on plant growth. (3) Results: Mustard (Sinapsis alba) was more sensitive to the presence of microplastics in the soil than sorghum (Sorghum saccharatum). The length of mustard shoots exposed to PLA-based plastic were shorter from 25% to about 56% than those in the control tests, while in the case of PHBV-based plastic, the decrease of mustard shoot length varied from 6% to 26%. The presence of the bioplastics studied, in particular the PLA-based one, at the levels of 2.5% w/w and higher contributed to reduced germination and shoot length and to the decrease in the relative chlorophyll content. (4) Conclusions: These three endpoints occurred to be more sensitive than the dry weight or elemental composition of plant biomass. They are recommended to be used in the evaluation of phytotoxicity of microbioplastics to study how to maintain the sustainability of the soil environment. Full article

Three-dimensional (3D) scanning and printing technologies enable the production of personalized rehabilitation splints, yet challenges such as scanning artifacts in complex anatomical areas (e.g., finger webs), lengthy post-processing, long printing times, and material limitations (e.g., brittleness and poor breathability) hinder routine clinical adoption. This feasibility study developed and evaluated a clinician-accessible protocol for fabricating cock-up wrist splints using 3D scanning (Creaform GO!SCAN 50 with VXelements 4.1), modeling (Materialise Magics), and fused deposition modeling printing with polylactic acid (PLA) on a MakerBot Replicator+. Five healthy participants wore the splints for one week, with user satisfaction assessed via the Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST 2.0; average total score 4.14/5, range 3.75–4.42) questionnaire. An experienced occupational therapist provided expert feedback. High satisfaction was reported for weight (4.6/5) and ease of use (4.6/5), confirming advantages over traditional thermoplastic splints in lightness and esthetics. However, lower scores for durability (3.6/5), comfort (3.6/5), and effectiveness (3.6/5) stemmed from PLA brittleness (cracking under load or overtightening), rough surfaces despite vapor polishing, inadequate ventilation causing moisture buildup, and fit issues (e.g., pressure points). Printing time averaged 9–19 h per splint. The protocol demonstrates proof-of-concept feasibility for clinicians with basic computer techniques, but material constraints and process refinements are required for reliable application in patient populations. Full article

Instrumented mouthguards (iMGs) enable in vivo monitoring of head-impact exposure by reporting event-level peak linear acceleration (PLA) and peak angular acceleration (PAA) in contact sports. This case study describes head impacts in a world-class Muay Thai fighter during routine sparring sessions over a two-week period leading into a competitive bout. Seven sparring sessions were monitored using an iMG (PROTeQT, HitIQ), and only manufacturer (in-mouth)-flagged events above the device’s 8 g trigger threshold were analyzed. Event-level data were exported from the manufacturer portal; raw time-series signals and proprietary signal-processing parameters were not accessible, and no independent video verification was performed. Across the camp, 590 impacts were recorded. Mean PLA values were modest across sessions (7.6 to 19.5 g), with one event exceeding 106 g (max PLA 162.2 g). In contrast, PAA exhibited greater variability, with multiple device-flagged events exceeding 7900 rad/s², particularly in Sessions 4, 6, and 7, where maximum PAA values reached 19,862 to 26,850 rad/s². Overall, these data indicate that sparring was predominantly low in translational loading, while occasionally producing high recorded rotational peaks. Because outputs are device- and processing-pipeline-specific and were not independently verified, threshold-based severity banding and extreme peaks should be interpreted cautiously. This case demonstrates the potential utility of iMG monitoring to characterize session-to-session variability in sparring exposure and to inform practical sparring load management strategies aimed at reducing cumulative head-impact burden. Full article

The increasing demand for sustainable and environmentally friendly construction materials has spurred interest in biopolymer composites reinforced with agricultural waste. Rice husk (RH), a byproduct of rice milling, is abundant and rich in lignocellulosic fibers and silica, making it excellent for use in fiber-reinforced biopolymers. The novelty of this study lies in its integrated and construction-oriented evaluation of rice husk (RH)-reinforced biopolymers, combining mechanical, thermal, environmental, and economic perspectives within a single framework. The study introduces a novel comparative approach by benchmarking multiple polymer matrices-including PP, recycled HDPE, epoxy, PLA, and bio-binders-under unified quantitative performance criteria. Another key novelty is the identification of the dual functional role of silica-rich RH in simultaneously enhancing structural strength and flame retardancy while contributing to carbon emission reduction. With a high silica content (15–20%) and lignocellulosic structure, RH serves as a natural filler that enhances the performance of polymer matrices such as polypropylene (PP), epoxy, polylactic acid (PLA), and recycled polyethylene. Mechanically, RH-reinforced composites demonstrate significant improvements in tensile, flexural, and impact strength. For example, PP composites with NaOH-treated RH and coffee husks achieved tensile strengths between 27.4 MPa and 37.4 MPa, with corresponding Young’s modulus values ranging from 1656 MPa to 2247.8 MPa. Recycled HDPE-RH blends reached tensile strengths up to 74 MPa and flexural values of 39 MPa, validating their structural applicability. Epoxy matrices embedded with 0.45 wt.% RH nanofibers showed degradation thresholds of 411 °C and 678 °C, reflecting substantial thermal resistance. Flame retardancy is further improved by the presence of RH biochar, which leads to reduced peak heat release rate (PHRR) and enhanced char formation. In building insulation applications, RH-based composites exhibit low thermal conductivity values between 0.08 and 0.14 W/m·K, contributing to energy efficiency. Economically, RH reduces material costs by 30–40%, while environmentally, its integration lowers carbon emissions in PP composites by up to 10%, and promotes biodegradability. Despite challenges such as moisture absorption and interfacial adhesion, these can be mitigated through alkali treatment, compatibilizers (e.g., MAPP), or hybrid reinforcement strategies. Full article

Polylactide (PLA) has become widely adopted across biomedical, packaging, and manufacturing sectors due to its biodegradability and renewable sourcing. However, the rapid growth in PLA consumption has created urgent challenges related to waste management and the cleaning of processing equipment. This study investigates glycolysis as a promising chemical depolymerization pathway for PLA recycling and in situ reactor cleaning. A systematic analysis of four glycolysis agents (GA) (ethylene glycol, diethylene glycol, propylene glycol, and glycerol) was performed across molar PLA:GA ratios from 1:0.125 to 1:4 at 220 °C, targeting the efficient conversion of high-molecular-weight PLA (Mn ≈ 165 kDa) into low-molecular-weight oligomers. Gel permeation chromatography (GPC) demonstrated that propylene glycol exhibited the highest depolymerization efficiency, yielding oligomers with Mn as low as 200 g·mol⁻¹ even at minimal glycolysis agent ratios, while glycerol produced hydroxyl-rich oligomers optimal for subsequent lactide synthesis. Hydroxyl value (HV) measurements showed excellent agreement with theoretical values (<5% deviation), allowing us to make an assumption about an approximate, close to near-quantitative con-version. Glycolysis products with Mw below 400 g·mol⁻¹ displayed excellent water solubility, making them particularly attractive for reactor cleaning applications. Using glycerol-derived (GL) oligomers (PLA:GL = 1:0.25), purified L-lactide with a melting point of 98.1 °C and high purity (>99%) was obtained through thermocatalytic depolymerization and five recrystallization cycles, as confirmed by ¹H nuclear magnetic resonance (¹H NMR) and differential scanning calorimetry (DSC) analyses. The recovered lactide’s high purity renders it suitable for ring-opening polymerization, enabling closed-loop PLA recycling schemes. Overall, glycolysis emerges as a highly promising chemical recycling route complementary to hydrolysis and pyrolysis: propylene glycol maximizes depolymerization efficiency for cleaning applications, while glycerol optimizes oligomer functionality for lactide recovery and advanced material synthesis. Our results provide practical guidelines for selecting glycolysis agents and conditions for cleaning and recycling applications. Full article

Background: Low estrogen levels during menopause reduce nitric oxide (NO) production, contributing to decline in skeletal muscle quality and function. Although acute and short-term dietary nitrate supplementation has demonstrated promising effects, long-term benefits, particularly on muscle quality in postmenopausal women, are not well established. Objectives: The objective was to investigate the effects of long-term (12-week) nitrate-rich beetroot extract supplementation on morphological and functional muscle quality, rate of force development (RFD), maximal strength, and circulating nitrate/nitrite concentrations in postmenopausal women. Methods: In a randomized, double-blind, placebo-controlled design, 20 postmenopausal women (21 years ± 7 since menopause) consumed 20 g/day of a nitrate-rich beetroot extract (BET; 548 mg nitrate/day) or a nitrate-depleted beetroot extract (PLA; 43 mg nitrate/day) for 12 weeks. Outcome measures, including muscle quality (functional via muscle strength/thickness ratio; morphological via ultrasound echo intensity), RFD, maximal voluntary isometric contraction (MVIC), and serum nitrate/nitrite levels, were evaluated at baseline, 8 weeks, and 12 weeks. Results: BET significantly increased serum nitrate (0.005) and nitrite (0.022) levels compared to PLA at both week 8 and week 12. Morphological muscle quality also improved significantly in the BET group (interaction effect, p = 0.014). Early-phase rate of force development (RFD) increased between 30 and 100 ms, whereas late-phase RFD increased between 100 and 200 ms. RFD_peak also improved by week 8, and these gains were maintained through week 12 (interaction effect, p < 0.05). Although there was no significant difference between groups for functional muscle quality, MVIC increased at week 12 in the BET group, but no significant Time × Group interaction was observed. Conclusions: Twelve weeks of nitrate-rich beetroot extract supplementation improved morphological muscle quality and RFD, suggesting potential clinical relevance for preventing structural and neuromuscular function decline in postmenopausal women. This study was registered with ReBEC (RBR-87qh649) and approved on 8 October 2024. Full article

Primary glomerulonephritis encompasses a diverse group of kidney diseases with variable clinical trajectories and outcomes. Accurate prognostic stratification is critical for guiding individualized management and improving long-term renal survival. This narrative review synthesizes current evidence on the prognostic value of histological grading systems, circulating and urinary biomarkers, and integrative risk prediction models across major primary glomerulonephritis subtypes, including IgA nephropathy, membranous nephropathy, and focal segmental glomerulosclerosis. Emphasis is placed on the utility of established classification systems (e.g., Oxford, MEST-C, chronicity scores), emerging tissue and fluid biomarkers (e.g., PLA2R antibodies, complement components, cytokine profiles), and the validation of multivariable prognostic tools and nomograms. We highlight areas of convergence between histopathologic lesions and molecular markers, as well as the evolving role of machine learning in predictive modeling. Ultimately, combining morphological, biochemical, and algorithmic tools holds promise for precision risk assessment and treatment tailoring in primary glomerulonephritis. Full article

Post-harvest deterioration in strawberries is an urgent and critical issue that requires significant attention. Glycerol monolaurate (GML), a broad-spectrum food-grade antimicrobial agent, faces limited applicability due to its poor water solubility. In this study, a confined encapsulation strategy was employed to encapsulate GML within hydroxypropyl-γ-cyclodextrin (HPγCD), which improved the physicochemical properties of GML and enhanced its stability in the environment. The fiber morphology was observed through scanning electron microscopy (SEM) and transmission electron microscopy (TEM), confirming the presence of a uniform, non-nodular core–shell structure. The Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) validated the successful encapsulation of GML within the cavity of HPγCD. Thermogravimetric analysis (TGA) demonstrated that the thermal stability of the core–shell system was significantly improved. In vitro release followed first-order kinetics (R² = 0.9842), with 79.5% of GML released over 68 h. The DPPH and ABTS assays demonstrated that PLA/GML-HPγCD NF exhibited sustained radical scavenging activity (p < 0.05, ANOVA). Compared to GML-HPγCD NF, PLA/GML-HPγCD NF exhibited prolonged antibacterial activity against Escherichia coli and superior antifungal efficacy in strawberry preservation. Meanwhile, PLA/GML-HPγCD NF significantly reduced lesion diameter and weight loss while maintaining hardness, total soluble solids, and vitamin C content over 8 days of storage. In conclusion, these characteristics highlighted the potential of P/G-HPγCD NF as a promising active packaging material for extending the shelf life of perishable fruits. Full article

Background: Sodium bicarbonate (SB) supplementation can enhance performance in short, high-intensity movements. However, its effectiveness in team sports such as rugby remains insufficiently explored. Methods: In this double-blind, parallel, controlled trial, 17 male professional rugby players ingested SB (0.3 g/kg) or a placebo 90 min before a high-intensity, rugby-specific training session monitored via GPS. The training session was conducted under real-world conditions to enhance ecological validity. Physical performance (countermovement jump, CMJ), fatigue markers (capillary lactate and ratings of perceived exertion, RPE), and gastrointestinal (GI) symptoms were assessed pre- and post-exercise. Results: No significant pre–post changes were observed in CMJ performance in either group. Lactate concentrations increased from pre- to post-exercise in both groups (both p < 0.001). The SB group showed higher GI symptom severity before, during and after exercise versus placebo, with several symptoms increasing over time solely in the SB group (p < 0.05). RPE increased similarly in both groups (SB: p = 0.012; PLA: p = 0.008). Due to the small sample size, only moderate-to-large within-group effects and very large between-group differences could be detected; therefore, the study was powered to detect moderate-to-large within-group effects but underpowered for detecting between-group differences. Conclusions: Acute SB ingestion at 0.3 g/kg did not result in detectable improvements in performance or fatigue markers during rugby-specific high-intensity training and was associated with a greater incidence of GI discomfort; however, the study was underpowered to detect small between-group differences. This study was registered on 23 May 2025 on ClinicalTrials.gov (NCT07017582). Full article

This research developed an active food packaging system featuring a tailored controlled-release mechanism. The system was fabricated using temperature-responsive poly(N-vinylcaprolactam) (PNVCL) nanofibers with a core-shell architecture. The resulting film incorporated cinnamon essential oil (CEO) as a natural preservative within a composite structure consisting of PNVCL, polyvinyl alcohol (PVA), polylactic acid (PLA) and CEO. The nanofiber film obtained via coaxial electrospinning exhibited a sandwich-like structure; the obtained fiber membrane is abbreviated as PP/PC, and the number represents the essential oil content. The PP/PC-4 composite demonstrated exceptional physical barrier properties and mechanical strength, with a WVP as high as 5.74 ± 0.37 (g·mm)/(m²·h·kPa). It also achieved the highest maximum force, elastic modulus, and tensile strength, recorded at 3.08 ± 0.31 N, 228.86 ± 15.46 MPa, and 5.26 ± 0.72 MPa, respectively, along with superior thermal stability. FTIR spectroscopy confirmed molecular interactions, specifically through C–H bonding, between the PLA/CEO core and the PNVCL shell layers. After 5 d of storage at 40 °C, the PP/PC-4 film retained substantial antibacterial efficacy. The antifungal efficacy demonstrated the highest performance, exceeding the control group by 32%. The weight loss rate on day four was 28%, significantly lower than other groups, while the hardness retention rate was 73% higher than the control group and 44% higher than PLA/CEO (4%). Application of this material prolonged the shelf life of Chinese bayberry (Myrica rubra) by 4 d while enhancing key preservation metrics. Owing to its advanced barrier properties, mechanical performance and temperature-modulated release characteristics, this PNVCL-based nanofiber film demonstrated strong potential as an intelligent packaging material for prolonging the freshness of perishable food products. Full article

This review highlights recent progress in the sustainable extraction, production and application of plant fiber-reinforced biopolymer composites. The review mainly focuses on properties of these materials—mechanical, thermal, and interfacial—and explores how factors such as fiber type, extraction methods, and surface treatments (e.g., enzymatic retting, deep eutectic solvents, steam explosion) affect fiber morphology and bonding with the polymer matrix. The work also discusses strategies to select and modify biopolymer matrices (e.g., PLA, PHA) for better compatibility, recyclability, and long-term performance, addressing challenges like fire resistance and environmental impact. Special attention is given to cellulose surface modification, which improves wettability and interfacial adhesion, while highlighting alternatives to conventional chemical treatments due to cellulose’s high crystallinity and strong hydrogen bonding. Despite advances in surface treatments and manufacturing, persistent challenges include moisture sensitivity, processing reproducibility, and standardization. Future research should prioritize application-tailored extraction, scalable eco-friendly modifications, and standardized testing to optimize durability and circular economy alignment. These fiber-reinforced biopolymer composites offer a viable path to fossil-free, high-performance materials. Overall, this review provides a comprehensive perspective that bridges sustainability and industrial applicability, offering practical guidance for developing high-performance, eco-friendly composites. Full article

In this work, polylactic acid (PLA) biocomposites reinforced with hemp granules of different sizes (1 mm and 2 mm) and contents (10, 20, and 30 wt.%) were systematically investigated. The study aimed to elucidate how granule size and concentration affect the rheological, thermal, and heat-transfer properties of the composites, with a focus on rheological parameters relevant to thermoforming. The results showed that increasing filler content enhanced stiffness, storage modulus (G′), and complex viscosity (η*), with smaller granules providing better reinforcement due to improved dispersion and interfacial adhesion. Thermal analyses confirmed a nucleating effect of hemp, slightly increasing crystallinity, while higher contents reduced thermal stability. The effect of filler content and size on heat transfer was discussed with respect to heating and cooling sensitivity during thermoforming, a key aspect of processability. The originality of this work lies in its integrated characterization strategy, which highlights the combined effect of granule size and concentration on the viscoelastic response and processing-relevant parameters of PLA-based biocomposites. These insights contribute to the development of sustainable biocomposites with improved potential for thermoforming applications. Full article

The ability to precisely control the morphology of polylactide (PLA) microparticles is crucial for their biomedical applications, yet it is a challenge due to the interdependent nature of key parameters such as size, porosity, and surface topology. This study presents a systematic approach to fabricating PLA microparticles with tunable architecture via emulsion-solvent evaporation by investigating the interplay of polymer molecular weight (44–442 kDa), solution concentration (0.5–20% w/v), and porogen type (PEG, alkanes, lithium salts). We achieved precise size control from 5 to 500 μm, dictated by solution viscosity and the polymer’s crystallization tendency, with poly(L-lactide) yielding irregular particles and poly(D,L-lactide) forming perfect spheres. Furthermore, porogen selection was critical for porosity: alkanes enabled tailored pore networks, with longer chains (e.g., decane) producing larger pores via enhanced phase separation, whereas the double-emulsion method with Li₂CO₃ proved superior for macroporosity due to its slow leaching kinetics. This work provides a foundational guideline for the rational design of PLA microparticles with customized properties for targeted applications in drug delivery and tissue engineering. Full article

This paper investigates the impact of tubed propeller design on the energy efficiency and acoustic emissions of sub-250 g quadcopters. This study was motivated by the growing popularity of ultralight UAVs and the lack of experimental data addressing the trade-offs between noise, efficiency, and mass. Ten drone configurations with varying tube geometries and tip clearances were constructed using 3D-printed PLA+ frames and identical propulsion components. Experimental tests were conducted in a reverberation room to measure sound pressure levels and onboard energy consumption during hover. The results show that tubed configurations are 3–6.5 dB louder than untubed ones, with a noticeable shift toward higher frequencies. While tubes increased total power demand by 18–37% compared to the lightest design, they also reduced it by 3–17% relative to untubed drones of the same mass. The findings demonstrate that tubing improves aerodynamic efficiency only under same mass constraints and is most beneficial when mechanical protection is prioritized over noise and endurance. Full article

Foodborne microplastics (MPs) are suspected carriers of co-ingested food contaminants, yet their digestive fate remains poorly characterized. This study simulates the role of environmentally aged polylactic acid (PLA) MPs—a common food-contact material—in transporting the antibiotic tetracycline (TC) through the human gastrointestinal tract. K₂S₂O₈-induced aging significantly increased PLA surface porosity, oxygen-containing groups, and hydrophilicity, elevating TC adsorption capacity from 0.54 to 0.95 mg/g. While adsorption kinetics were consistent with pseudo-second-order behavior, mechanistic analysis indicates that aging promotes interactions dominated by hydrogen bonding and electrostatic forces, rather than purely physical deposition. Critically, in vitro digestion models revealed that simulated intestinal fluid significantly enhances TC release (up to 62.7% of adsorbed load) compared to gastric conditions. Sequential gastrointestinal simulation yielded a bioaccessibility of 32.6%, indicating substantial digestive mobilization of MP-bound antibiotics. These findings underscore the potential of aged PLA MPs to act as digestive-stage “Trojan horses” for foodborne antibiotics. Our integrated approach—combining controlled aging, adsorption thermodynamics, and physiologically relevant digestion models—provides a mechanistic screening framework for assessing the bioaccessibility and exposure potential of microplastic-vectored contaminants in food safety contexts. Full article