Search Results (582)

While material extrusion via fused filament fabrication (FFF) offers design flexibility and rapid prototyping, its practical use in engineering is limited by mechanical challenges, including residual stresses, geometric distortions, and potential interlayer debonding. These issues arise from the dynamic thermal profiles during FFF, including temperature gradients, non-uniform hardening, and rapid thermal cycling, which lead to uneven internal stress development depending on fabrication parameters and object topology. These problems can compromise the structural integrity and mechanical properties of FFF parts, especially when the load-bearing capacity and geometric accuracy are critical. This study focuses on polylactic acid (PLA) due to its widespread application in engineering. It introduces a computational framework for coupled thermo-mechanical simulations of the FFF process using ABAQUS (Version 2020) finite element software. A key innovation is an automated subroutine that converts G-code into a time-resolved event series for finite element activation. The simulation framework explicitly models the sequential stages of printing, cooling, and detachment, enabling prediction of adhesive loss and post-process warpage. A transient thermal model evaluates the temperature distribution during FFF, providing boundary conditions for a mechanical simulation that predicts residual stresses and warping. Uniquely, the proposed model incorporates the detachment stage, enabling a more realistic and experimentally validated prediction of warpage and residual stress release in FFF-fabricated components. Although the average deviation between predicted and measured displacements is about 10.6%, the simulation adequately reflects the spatial distribution and magnitude of warpage, confirming its practical usefulness for process optimization and design validation. Full article

Prognostic uncertainty and missed diagnoses of sepsis remain frequent after cardiopulmonary bypass (CPB) surgery, where systemic inflammatory response (SIRS) arises from surgical trauma, blood activation in the extracorporeal circuit, ischemia/reperfusion injury, and endotoxin release. Among innovative biomarkers, pro-adrenomedullin (pro-ADM), particularly its stable fragment mid-regional pro-adrenomedullin (MR-proADM), has shown promise for detecting endothelial dysfunction and predicting organ failure in sepsis. SeptiCyte^® RAPID (Seattle, WA, USA) also represents a novel diagnostic tool that assesses the host immune response by quantifying PLA2G7 and PLAC8 gene expression in whole blood, offering potential for early differentiation between sepsis and sterile inflammation. We analyzed traditional and innovative biomarkers within 24 h post-CPB in a pilot group of patients admitted to the cardiac Intensive Care Unit of the “Città della Salute e della Scienza” University Hospital (Turin, Italy) between June and November 2023. Data from the following 14 patients were collected: 7 undergoing surgery for infective endocarditis (IE, Group 1) and 7 having standard elective cardiac surgery (Group 2). Procalcitonin (PCT), lactate, and pro-ADM increased in Group 1 but not in Group 2. SeptiCyte^® RAPID showed a moderate, borderline increase in Group 1. The innovative biomarkers had a good performance in patients exhibiting signs of organ dysfunction and in subjects demonstrating at least cardiovascular and/or pulmonary damage and under vasopressor and inotropic support. Although limited by the small sample, our preliminary data suggest no biomarker alterations in patients with standard elective cardiac surgery, unlike in those with IE. Full article

The synthesis of two series of poly(lactic acid) (PLA)-based polymer nanocomposites (PNCs) filled with small amounts (0.5 and 1%) of Ag and Cu nanoparticles (NPs) was performed. Moreover, two methods for the PNC synthesis were performed, namely, ‘conventional mixing techniques’ and ‘in situ ring opening polymerization (ROP)’. The latter method was employed for the first time; moreover, it was found to be more effective in achieving very good NP dispersion in the polymer matrix as well as the formation of interfacial polymer–NP interactions. The in situ ROP for PLA/Cu was not productive due to the oxidation of Cu NPs being faster than the initiation of ROP. The presence of NPs resulted in suppression of the glass transition temperature, T_g (23–60 °C), with the effects being by far stronger in the case of ROP-based PNCs, e.g., exhibiting T_g decrease by tens of K. Due to that surprising result, the ROP-based PLA/Ag PNCs exhibited elevated ionic conductivity phenomena (at room temperature). This can be exploited in specific applications, e.g., mimicking the facilitated small molecules permeation. The effects of NPs on crystallinity (2–39%) were found opposite between the two series. Crystallinity was facilitated/suppressed in the mixing/ROP -based PNCs, respectively. The local and segmental molecular mobility map was constructed for these systems for the first time. Combining the overall data, a concluding scenario was employed, that involved the densification of the polymer close to the NPs’ surface and the free volume increase away from them. Finally, an exceptional effect was observed in PLA + 0.5% Ag (ROP). The crystallization involvement resulted in a severe suppression of T_g (−25 °C). Full article

This study addresses critical bottlenecks in photocatalytic water treatment technologies, including difficulties in recovering traditional powdered catalysts, low mass transfer efficiency in immobilized reactors, and limited structural diversity. By integrating topology optimization with 3D printing technology, we designed and fabricated five types of triply periodic minimal surface photocatalytic reactors (TPMS-PCRs) with hierarchical porous structures—Fischer-Radin-Dunn (FRD), Neovius (N), Diamond (D), I-graph Wrapped Package (IWP) and Gyroid (G). Using fused deposition modeling (FDM), these TPMS configurations were manufactured from polylactic acid (PLA), 1.5 wt% TiO₂/PLA, and 2.5 wt% TiO₂/PLA. The catalytic degradation performance of these structurally distinct reactors for organic pollutants varied significantly. Notably, the FRD-type TPMS-PCR loaded with 2.5 wt% TiO₂ achieved a methylene blue (MB) degradation rate of 93.4% within 2.5 h under rotational flow conditions, compared to 87.5% under horizontal flow conditions. Full article

Recurrence of the original glomerular disease (GN) poses a significant threat to kidney transplant function and longevity. The probability and severity of this recurrence vary, with C3 glomerulopathy and certain forms of FSGS exhibiting particularly high rates. Kidney transplant GN recurrence risk hinges on the characteristics of the initial GN, recipient/donor genetics, recipient age, donor type, end-stage kidney disease (ESRD) progression rate, and proteinuria levels. Standard immunosuppression has limited efficacy in preventing primary disease recurrence; however, agent selection and induction therapy can influence the risk for specific GNs. Diagnosing recurrent GN involves a comprehensive approach, including clinical evaluation, laboratory tests (such as proteinuria, hematuria, and specific biomarkers like anti-PLA2R for membranous nephropathy or complement for C3G), and, critically, an allograft biopsy analyzed with light, immunofluorescence, and electron microscopy. Treatment strategies are evolving towards targeted therapies, such as rituximab for antibody-mediated GN and complement inhibitors for C3G, moving away from broad immunosuppression. This narrative literature review provides practical monitoring algorithms for post-transplant settings, synthesizing information on the incidence, predictors, diagnostic strategies, and therapeutic options for various glomerular disease subtypes. The methodology involved searching MEDLINE, Embase, and Cochrane databases from 1996 to 2025, prioritizing systematic reviews, cohort studies, registries, and interventional reports. Eligibility criteria included adult transplant recipients and English-language reports on recurrent glomerular disease outcomes, excluding most single-patient case reports. Limitations include potential selection bias, omission of relevant studies, and the absence of a formal risk-of-bias assessment or meta-analysis. The evidence base is heterogeneous, with inconsistent outcome reporting and scarce randomized controlled trials. Future efforts should focus on developing predictive biomarkers, standardizing diagnostic and response criteria, conducting multicenter prospective cohorts and pragmatic trials, and creating shared registries with harmonized data. Full article

This study investigated PLA/PCL blends modified with maleic anhydride (MA) via radical grafting using benzoyl peroxide (BPO) as an initiator. Different formulations with 5 and 10 wt.% of PLA-g-MA (containing 1, 3, and 5 wt.% MA) were prepared to evaluate their compatibilizing effect. Samples were characterized thermally, mechanically, and morphologically using DSC, TGA, FTIR, goniometry, SEM, and tensile, impact, and hardness tests. The results show that adding PCL significantly improves the ductility of PLA, though it reduces tensile strength and hardness. Grafting with MA partially improves phase compatibility, as seen by increased elongation at break and impact resistance, especially at intermediate MA concentrations (1–3%). However, higher MA contents lead to greater variability in thermal and mechanical results, likely due to heterogeneous phase dispersion. FTIR analysis detected residual BPO in some formulations, though below 0.1 phr. TGA indicated a slight improvement in thermal stability at 5 wt.% MA. Overall, the findings suggest that controlled use of MA as a compatibilizer enhances the balance of mechanical and thermal properties in PLA/PCL systems. Full article

Background: As a globally significant aquaculture species, elucidating the molecular mechanisms underlying the regulation of the Pacific White Shrimp (Litopenaeus vannamei) growth holds substantial scientific and industrial value. This study systematically investigates the role of the LvChia2 gene in governing growth and development through a cross-tissue metabolic network approach. Methods: RNA knockdown (RNAi)-mediated knockdown of LvChia2 significantly impaired growth performance and triggered a tissue-specific metabolic compensation mechanism. Results: This mechanism was characterized by reduced crude lipid content in muscle and adaptive modulation of lipase (LPS) activities in hepatopancreatic and intestinal tissues, suggesting inter-tissue metabolic coordination. Transcriptomic profiling identified 610 differentially expressed genes (DEGs), forming a three-dimensional regulatory network encompassing “energy metabolism, molt regulation, and nutrient utilization.” Key mechanistic insights revealed the following: (1) Enhanced mitochondrial energy transduction through the upregulation of ATP synthase subunits and NADH dehydrogenase (ND-SGDH). (2) The disruption of ecdysteroid signaling pathways via suppression of Krueppel homolog 1 (Kr-h1). (3) The coordinated regulation of nitrogen metabolism through the downregulation of glutamine synthetase and secretory phospholipase A2. These molecular adaptations, coupled with tissue-specific oxidative stress responses, reflect an integrated physiological strategy for environmental adaptation. Conclusions: Notably, this study provides the first evidence in crustaceans of chitinase-mediated growth regulation through cross-tissue metabolic interactions and identifies six core functional genes (ATP5L, ATP5G, ND-SGDH, Kr-h1, GS, sPLA2) as potential targets for molecular breeding. A novel “gut-hepatopancreas axis” energy compensation mechanism is proposed, offering insights into resource allocation during metabolic stress. These findings advance our understanding of crustacean growth regulation and establish a theoretical foundation for precision aquaculture strategies, including genome editing and multi-trait genomic selection. Full article

Background/Objectives: Biodegradable and pH-responsive nanocarriers using zwitterionic moieties represent a promising avenue for targeted delivery of chemotherapeutics. The present study addresses this by developing zwitterionic nanoparticles based on polylactic acid/poly(ethylene adipate) (PLA/PEAd) copolymers grafted with SBMA, designed to combine acid-triggered drug release with stealth-like biocompatibility. Methods: A series of polylactic acid/poly(ethylene adipate) (PLA/PEAd) copolymers with varying compositions (95/5, 90/10, and 75/25 w/w) were synthesized via ring-opening polymerization, followed by controlled radical grafting of the zwitterionic monomer [2-(Methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (SBMA), which was then successfully grafted upon their backbone. The resulting zwittenionic copolymers were thoroughly characterized for their structural and physicochemical properties, displaying tunable molecular weights of 3200–4900 g/mol, enhanced hydrophilicity and controlled degradation, with mass loss ranging from 8% to 83% over 30 days, depending on PEAd content and pH. Paclitaxel-loaded nanoparticles of spherical shape with sizes ranging from 220 to 565 nm were then fabricated. Drug release was pH-dependent with significantly higher release at pH 5.0 (up to ~79% for PLAPEAd7525-SBMA) compared to pH 7.4 (~18–35%). Hemolysis assays demonstrated excellent hemocompatibility, and cytotoxicity studies showed strong anticancer activity (>80% cell death in MDA-MB-231) with lower toxicity toward iMEFs, especially for PEAd-rich formulations. Conclusions: Our findings underline the potential of SBMA-functionalized PLA/PEAd nanoparticles as effective nano-carriers for tumor-targeted chemotherapy. Full article

This study focuses on the synthesis and characterization of thermoresponsive hydrogels of poly(lactic acid) (PLA) and poly(ethylene glycol) (PEG), PLA–PEG copolymers, aiming at the targeted and controlled release of deferoxamine (DFO), a clinically applied iron-chelating drug. Triblock (PLA-PEG-PLA) and diblock (mPEG-PLA) copolymers were synthesized using ring-opening polymerization (ROP) with five different PEGs with molecular weights of 1000, 1500, 2000, 4000, and 6000 g/mol and two types of lactide (L-lactide and D-lactide). Emulsions of the polymers in phosphate-buffered saline (PBS) were prepared at concentrations ranging from 10% to 50% w/w to study the sol–gel transition properties of the copolymers. Amongst the synthesized copolymers, only those that demonstrated thermoresponsive sol-to-gel transitions near physiological temperature (37 °C) were selected for further analysis. Structural and molecular confirmation was performed by Nuclear Magnetic Resonance (NMR) and Fourier-transform infrared spectroscopy (FTIR), while the molecular weights were determined via Gel Permeation Chromatography (GPC). The thermal transitions were studied by calorimetry (DSC) and crystallinity via X-ray diffraction (XRD) analysis. DFO-loaded hydrogels were prepared, and their drug release profiles were investigated under simulated physiological conditions (37 °C) for seven days using HPLC analysis. The thermoresponsive characteristics of these systems can offer a promising strategy for injectable drug delivery applications, where micelles serve as drug carriers and undergo in situ gelation, enabling controlled release. This alternative procedure may significantly improve the bioavailability of DFO and enhance patient compliance by addressing key limitations of conventional administration routes. Full article

The growing demand for sustainable packaging materials highlights the need for bio-based alternatives to fossil-derived polymers, particularly in barrier applications where reduced environmental impact and recyclability are critical. Poly(lactic acid) is a promising candidate due to its renewable origin and biodegradability, yet its application in aqueous dispersion coatings remains underdeveloped. In this study, copolymers were synthesized from L-(+)-lactic acid, itaconic acid, and 1,4-/2,3-butanediol via polycondensation, and a solvent-free thermomechanical method was used to prepare aqueous dispersions from the produced copolymers. The main objective of this study was to identify an optimal composition for the copolymer and dispersion to achieve small and uniformly sized dispersion particles while also assessing the scalability of the process from laboratory to pilot production. The smallest dispersion particles and most uniform size distribution were achieved with a copolymer that had an M_n close to the average (10,180 g mol⁻¹) and a low T_g (−1.4 °C). The grade and dosage of the dispersion stabilizer significantly influenced the particle size and particle size distribution. The process scale-up, including polymer production at pilot scale and dispersion preparation at bench scale, was successfully demonstrated. The water vapor barrier properties of the coated dispersions were promising (<10 g/m² at 23 °C/50% RH), supporting the potential of aqueous PLA-based dispersions as sustainable barrier coatings. Full article

This study investigated the toxicity of ten polymer materials intended for the development of invasive neural interfaces improving the treatment of neurological diseases. Most of the materials for neural implants can cause traumatization of the surrounding tissue, inflammation, and foreign body reaction. In this study, in vitro and in vivo toxicity assessment was performed for nylon 618 (NY), polycaprolactone (PCL), polyethylene glycol diacrylate (PEGDA), polydimethylsiloxane (PDMS), polyethylene terephthalate (PET), polylactide (PLA), thermoplastic polyurethane (TPU), polypropylene (PP), polyethylene terephthalate glycol (PET-G), and polyimide (PI). The biocompatibility of these ten materials was assessed based on cell adhesion, growth and cytotoxicity on neural (PC-12) and fibroblast (NRK-49F) cultures. Furthermore, brain tissue responses to the implanted phantom scaffolds were analyzed in rats. According to these measurements, PI showed the highest compatibility for both cell types. PEGDA exhibited cytotoxic effects, low cell adhesion and the strongest foreign body reaction, including fibrosis and multinucleated cell formation. The other polymers showed lower pathological responses which makes them potentially usable for neural interfacing. We conclude that PEGDA appears to be unsuitable for long-term use due to adverse tissue and cellular reactions, whereas PI, PLA, PDMS and TPU hold promise as materials for safe and effective neural interface applications. Full article

Argasid ticks Ornithodoros erraticus and Ornithodoros moubata are major vectors of zoonotic pathogens, including the African swine fever virus and relapsing fever Borrelia spp., and their control is essential to reduce disease transmission. In this study, we evaluated the immunogenicity and protective efficacy of four Ornithodoros tick antigens formulated as mRNA–lipid nanoparticles (mRNA-LNPs): OeSOD, OeTSP1, OmPLA2, and Om86. Rabbits were immunised with three doses of each mRNA-LNP construct, and immune responses and tick biological parameters were assessed following infestation with both tick species. All mRNA-LNP constructs induced antigen-specific IgG responses that recognised native proteins in tick saliva and midgut extracts. Vaccination resulted in significant reductions in female oviposition and fertility, which correlated with antibody levels, and yielded protective efficacies of 21.9–41.6% against O. moubata and 23.1–41.6% against O. erraticus. Notably, the mRNA-LNPs of OeSOD and OeTSP1 outperformed their recombinant counterparts against O. moubata, and Om86 mRNA-LNP conferred markedly improved protection against both O. moubata and O. erraticus. These findings highlight the potential of mRNA-LNP vaccines to induce effective anti-argasid tick immunity and provide a promising platform for the development of sustainable strategies to control argasid ticks and associated pathogens. Full article

The growing demand for sustainable technologies in the extraction and functionalization of bioactive compounds has driven the development of innovative, eco-efficient methodologies. This study assesses the feasibility of high-pressure green technologies—Enhanced Solvent Extraction (ESE) and Pressurized Liquid Extraction (PLE)—for extracting bioactive compounds from the leaves of Petiveria alliacea, a medicinal plant with significant pharmacological potential. The extracts obtained under optimal PLE conditions (100 bar, 75 °C, ethanol/water: 50:50 v/v) exhibited the highest total phenolic content (76.27 mg GAE/g) and notable antioxidant capacity. The same extract was tested for its antimicrobial activity against Escherichia coli, showing a minimum inhibitory concentration (MIC) of 9.48 µg/mL. Furthermore, the extract was successfully impregnated into polylactic acid (PLA) filaments via supercritical CO₂ processing, achieving a maximum antioxidant inhibition of 6.81% under mild conditions (100 bar, 35 °C). The combination of pressurized extraction and supercritical impregnation provides a scalable and environmentally friendly pathway for producing functional biomaterials. These findings highlight the potential of integrating green extraction and material functionalization within the context of the circular bioeconomy and industrial biotechnology. Full article

This paper presents a detailed analysis of the thermal and flammability properties of polylactide- (PLA) and poly(ethylene terephthalate)- (PET) based polymer blends with biofillers, such as calcium lignosulfonate (CLS), lignosulfonamide (SA) and lignosulfonate modified with tannic acid (BMT) and gallic acid (BMG). Calorimetric studies revealed the presence of two glass transitions, one cold crystallization temperature, and two melting points, confirming the partial immiscibility of the PLA and PET phases. The additives had different effects on the temperatures and ranges of phase transformations—BMT restricted PLA chain mobility, while CLS acted as a nucleating agent that promoted crystallization. Thermogravimetric analyses (TGA) analyses showed that the additives significantly affected the thermal stability under oxidizing conditions, some (e.g., BMG) lowered the onset degradation temperature, while the others (BMT, SA) increased the residual char content. The additives also altered combustion behavior; particularly BMG that most effectively reduced flammability, promoted char formation, and extended combustion time. CLS reduced PET flammability more effectively than PLA, especially at higher PET content (e.g., 65% reduction in PET for 2:1/CLS). SA inhibited only PLA combustion, with strong effects at higher PLA content (up to 76% reduction for 2:1/SA). BMT mainly reduced PET flammability (48% reduction in 1:1/BMT), while BMG inhibited PET more strongly at lower PET content (76% reduction for 2:1/BMG). The effect of each additive also depended on the PLA:PET ratio in the blend. FTIR analysis of the char residues revealed functional groups associated with decomposition products of carboxylic acids and aromatic esters. Ultimately, only blends containing BMT and BMG met the requirements for flammability class FV-1, while SA met FV-2 classification. BMG was the most effective additive, offering enhanced thermal stability, ignition delay, and durable char formation, making it a promising bio- based flame retardant for sustainable polyester materials. Full article

The spleen is essential for immunity, mediating host defense against pathogens and regulating immunological homeostasis. Western-style diets commonly cause the aggregation of body fat and the emergence of obesity. This state might lead to damage to the spleen’s functions. However, the effects of Western-style diets on gene expression and metabolic regulation in the spleen have not yet been fully explored. In this study, C57BL/6 mice were fed either a high-fat diet (HFD) or standard chow (CHFD) for 10 weeks starting at 8 weeks old. Weekly weights were recorded, and spleens were weighed at 18 weeks. The results showed that HFD mice had significantly higher body weights from 12 weeks (p < 0.05) and a higher splenic index at 18 weeks (p < 0.01). HE staining revealed disrupted spleen structures and infarcted areas in the HFD group. Transcriptome sequencing highlighted immune-related pathways, including inflammatory response and interleukin-6 production. Among the differentially expressed genes (DEGs), PCK1, ALDH9A1, and ALDH7A1 were significantly upregulated in the HFD group, whereas PLA2G2F and PLA2G4F exhibited significant downregulation. APOB emerged as a key hub gene in PPI analysis. Metabolomics analysis identified significantly different metabolites (SDMs), including Rifamycins, 7-Ketodeoxycholic Acid, Folinic Acid, and Lotaustralin, as key biomarkers for an HFD, while 1-Methylnicotinamide and Prostaglandin E1 were significant for CHFD. KEGG enrichment linked glycerophospholipid and arachidonic acid metabolism to both transcriptome and metabolome results. The joint analysis of transcriptome and metabolome data revealed that SLC22A8 was negatively correlated with Biliverdin and 1-methylnicotinamide, and MCPT1 was inversely correlated with 7-Ketodeoxycholic Acid. These findings offer insights into the molecular mechanisms and metabolites that influence spleen immunity and systemic immune homeostasis. Full article