Journals
2026 EN
Magalhães Bergamini Raphael Borges · Tavares Maria Inês Bruno · Farias Camila Vicente
+3 more
ABSTRACT Polypropylene (PP) composite fibers containing 0.10, 0.20, and 0.50 wt% molybdenum oxide (MoO 3 ) nanoparticles were produced via melt spinning. In the present study, the effect of this addition on the mechanical, thermal, and chromic properties of the fibers was investigated. Scanning electron microscopy confirmed good dispersion of the nanofiller within the PP matrix at low concentrations (0.10 wt%) and the presence of agglomerates in samples containing higher amounts. Additionally, a modest nucleating effect associated with the filler was observed, with an increase in the degree of crystallinity of the fibers and an improvement in the limiting oxygen index in all samples compared to the control. On the other hand, molybdenum accelerated the initial decomposition of PP and decreased the melt viscosity, indicating possible polymer degradation in the filled materials. The mechanical properties were investigated, highlighting an approximately 8% increase in the tenacity of the yarn containing the lowest amount of the metal oxide and a considerable loss of tensile strength in the yarns with 0.20 and 0.50 wt%, attributed to poor filler dispersion. A thermochromic effect was observed in the PP/MoO 3 masterbatch containing 5.00 wt% of the nanofiller and in the fibers after the extrusion process, with a color change from white to blue in these materials.
Journals
2026 EN
Kuznik Irina · Bertram Paul · Ernst Katharina Maria
+2 more
ABSTRACT Chitosan fibers (CHS) are a promising bio‐based precursor for carbon materials. However, their stabilization behavior and early‐stage thermal conversion are not well understood in fiber form. This study systematically investigated the thermo‐oxidative stabilization of chitosan yarns using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and Fourier‐transform infrared spectroscopy (FTIR) in air and nitrogen atmospheres. Stepwise stabilization experiments revealed that major chemical transformations, including dehydration, cleavage of CO/COC linkages, and changes in C–H functionalities, were largely complete within 15 min at the investigated temperatures. Extended dwell times confirmed reaction completion and revealed minor residual endothermic processes at higher temperatures. FTIR analysis showed that stabilization primarily alters functional group chemistry while leaving the overall nitrogen content largely unaffected. Carbonization experiments conducted to evaluate carbon yield showed that stabilized fibers exhibited carbon yields comparable to or slightly lower than those obtained by direct carbonization. These results provide insight into the stabilization behavior of CHS and clarify the roles of atmosphere and dwell time during early thermal conversion. This contributes to our understanding of fiber‐based chitosan precursors for developing carbon materials.
Journals
2026 EN
Chen Jingwen · OkamotoSchalch Nadia O. · Dalben Maria Gabriela B.
+4 more
ABSTRACT This study investigated two types of lignin‐containing nanocelluloses derived from grape pomace and their applications as coatings on PLA. First, bleached and unbleached grape pomace‐derived nanocelluloses (BGNC and UGNC) were extracted. Atomic force microscopy (AFM) and transmission electron microscopy (TEM) revealed a mix of nanofibrils and well‐defined nanocrystals from BGNC and only nanofibrils from UGNC. BGNC exhibited a higher crystallinity (25.2%) compared to UGNC (20.2%), both with preserved native cellulose type I structure. Thermogravimetric analysis (TGA) showed that residual lignin was present in both samples although strongly reduced after bleaching. BGNC or UGNC coatings were applied via bar‐coating at theoretical thicknesses of 90, 140, and 1540 nm. Due to its higher lignin content, the UGNC‐coated surface was more hydrophobic, an interesting property for packaging, while the BGNC‐coated film showed better oxygen barrier properties thanks to its higher crystallinity and more uniform coating. BGNC‐coated film exhibited a good oxygen barrier with a permeability (OP) of 5.91 × 10 −19 m 3 m/m 2 s Pa at 90 nm thickness, while the UGNC‐coated film only reached 9.40 × 10 −19 m 3 m/m 2 s Pa. The oxygen barrier and hydrophobicity are both promising features, highlighting the potential application of by‐product‐derived nanocelluloses for bio‐based, compostable food packaging and the interest of lower‐impact chemical extractions to develop original properties.
Journals
2026 EN
Quevedo Bruna V. · Juvencio Luiz Ricardo Furlan · Asami Jessica
+4 more
ABSTRACT Burns are complex injuries that require effective and multifunctional therapeutic approaches. Polymeric biomaterials that combine synthetic and natural polymers have emerged as promising wound dressings due to their ability to promote tissue regeneration and enhance the healing process. In this context, this study aimed to develop a crosslinked blend of poly(vinyl alcohol) (PVA), chitosan (CS), and collagen (Coll), obtained through the freeze–thawing process, for application in burn wound dressings. FTIR analysis confirmed the presence of intermolecular interactions, mainly hydrogen bonding, between PVA and CS. TGA and DSC analyses indicated that the incorporation of CS resulted in enhanced thermal stability of the film and a reduction in crystallinity compared to pure PVA, respectively. SEM revealed a homogeneous morphology without phase separation, indicating good compatibility among the polymers. Additionally, PVA/CS/Coll films exhibited a higher swelling degree than pure PVA films, indicating an improved fluid absorption capacity. In vivo burn wound assays in an animal model demonstrated that the material promotes re‐epithelialization and tissue healing within 14 days in groups treated with these films. Therefore, these results demonstrate that the PVA/CS/Coll biomaterial combines favorable structural, thermal, and biological properties, highlighting its strong potential as a low‐cost and effective material for advanced burn wound dressings.
Journals
2026 EN
Schutz Guilherme Frey · Coutinho Ana Luiza Assis · Zuliani Carolina Coli
+5 more
ABSTRACT In this study, biocompatible hydrogels intended for topical delivery of ibuprofen were synthesized from gelatin methacryloyl (GelMA) and 2‐(dimethylamino)ethyl methacrylate (DMAEMA) by varying their proportions. The impact of different GelMA and DMAEMA ratios was comprehensively evaluated through several analyses, including scanning electron microscopy (SEM), Fourier‐transform infrared spectroscopy (FT‐IR), thermogravimetric analysis (TGA), rheological assessments, swelling capability, mechanical property evaluations, cytotoxicity, and drug release studies. We found that the addition of 25% DMAEMA (formulation DMAEMA25) significantly increased the stiffness of the hydrogel, from 7.3 × 10 4 to 1.24 × 10 5 Pa, reaching values comparable to the stiffness of human skin. Additionally, this formulation was not cytotoxic, and drug incorporation was more efficient in it, reaching 57% compared to 18% in pure GelMA. The DMAEMA25 hydrogel also exhibited sustained drug release behavior, accurately described by the Weibull model. These characteristics highlight the potential of the developed hydrogels for use in customized, modulated ibuprofen delivery systems.
Journals
2026 EN
Silveira Ronaldo Bianchini · Ebs Maria Fernanda Pedro · Bochanoski Renata
+4 more
ABSTRACT Skin injuries resulting from trauma, burns, or chronic conditions such as diabetes often require advanced medical interventions, as conventional dressings provide only passive protection with limited exudate absorption and minimal contribution to healing. In this study, electrospun poly(ε‐caprolactone)/poly(ethylene oxide) (PCL/PEO) membranes were engineered to couple extracellular matrix (ECM)‐like architecture with tunable wettability, fluid absorption, and degradation to achieve enhanced wound closure. By adjusting electrospinning parameters, uniform fibers (2.4–7.4 μm) with porosity of 63%–77% and pore sizes of 17–25 μm were obtained. FTIR analysis confirmed the successful blend of PCL and PEO, while wettability, fluid absorption, and membrane degradation increased proportionally with PEO content; the optimized PCL7:1PEO membrane exhibited a contact angle below 60° and fluid uptake of 361%. Biological assays demonstrated preserved cytocompatibility and enhanced fibroblast migration, achieving wound closure of 86.8% ± 14.6% for PCL7:1PEO compared with 68.3% ± 7.7% for pristine PCL and 75.6% ± 3.8% for the control. These findings highlight the potential of PCL/PEO electrospun membranes as functional wound dressings, offering prolonged use, improved fluid management, and a favorable microenvironment for tissue repair, representing a promising alternative to conventional treatments.
Journals
2026 EN
Rehm Oliver · Baumgarten Lutz · Wunderwald Florian
+7 more
ABSTRACT The current market launch of HfO 2 ‐based ferroelectric devices relies on the control of the inherent oxygen vacancies (OVs) and their impact on the ferroelectric performance. Due to the necessary stabilization of the ferroelectric phase by doping, several dopants are investigated for their applicability to control the vacancy concentration. Hf3 + $^{3+}$ signatures in X‐ray photoemission spectra are often used as an indication of OVs for both qualitative and quantitative analysis. The analysis of Y doped HfO 2 (Y:HfO 2 ) as investigated by hard x‐ray photoelectron spectroscopy (HAXPES) reveals the inapplicability of the Hf3 + $^{3+}$ signature for a quantitative determination of OVs in the case of heterovalent doping and is restricted to pure HfO 2 or isoelectronic substitution of Hf by, for example, Zr.
Journals
2026 EN
Scapolatiello Annalisa · Samassa Chiara · Gandolfi Andrea
+4 more
ABSTRACT Interspecific hybridization poses a major challenge to biodiversity conservation, as genetic introgression can threaten the persistence of native species. This phenomenon occurs when individuals from distinct species interbreed, producing hybrids with a combination of genetic traits from both parents. The implications are especially concerning when these hybrids are fertile and able to backcross with the parental species, potentially leading to the permanent integration of foreign genetic material into native populations. Human‐mediated translocations further increase hybridization risk by bringing reproductively compatible species into contact. Detecting introgression in individuals that cannot be reliably distinguished morphologically is therefore crucial for conservation planning. In this study, we investigate hybridization between the southern pike ( Esox flaviae ) and northern pike ( Esox lucius ) in Italy and Central Europe. We evaluate multilocus intron polymorphisms (MIPs) as a molecular tool for species identification and hybrid detection by analysing pike samples using a combination of previously available MIP loci and newly isolated pike‐specific MIPs. Our results show that MIP loci successfully reproduce patterns previously identified with microsatellites, confirming their suitability for detecting hybridization and interspecific genetic structure. We also developed a panel of diagnostic loci enabling rapid species/hybrids identification for routine applications. This is the first study demonstrating the effectiveness of MIPs for accurate species assignment and assessment of genetic diversity in pike, particularly in the context of hybridization and its conservation implications. Overall, our findings highlight the value of MIPs as complementary molecular markers for biodiversity studies, providing practical diagnostic tools for species monitoring and management in conservation programmes.
Journals
2026 EN
Maltchik Leonardo · Piedade Maria Teresa Fernandez · Schöngart Jochen
+8 more
ABSTRACT February 2, World Wetlands Day, highlights the vital role of wetlands in biodiversity, climate regulation, food systems and human livelihoods. Although they cover a small fraction of Earth's surface, wetlands provide a disproportionate share of ecosystem services and mitigate climate change through carbon sequestration. Yet, over one‐third of global wetlands have been lost in recent decades, weakening their ability to buffer climate extremes. Despite advances under frameworks such as the Ramsar Convention, protection remains fragmented and insufficient. We argue that effective conservation requires large‐scale financial mechanisms and propose initiating discussions toward a Wetlands Forever Facility to enable integrated, equitable investments.
Journals
2026 EN
Schindler Mike · Flaum Benjamin · Manafzadeh Armita Razieh
+6 more
Abstract Prokinesis—in which a craniofacial joint allows the rostrum to move relative to the braincase—is thought to confer diverse advantages in birds, mostly for feeding. A craniofacial joint would, however, be a weak link if cranial stability is important. Paradoxically, we have identified a craniofacial joint in helmeted hornbills ( Rhinoplax vigil ), birds known for violent head‐butting behavior. To understand how the helmeted hornbill balances the competing demands of kinesis and collision, we combine manual craniofacial joint manipulation, skull micro‐computed tomography (μCT) and articular raycasting, also comparing our data with μCT scans of 10 closely‐related species that do not aggressively head‐butt. The helmeted hornbill boasts a particularly massive casque, a distinctive upper mandible protrusion fronting the braincase; the craniofacial joint is immediately caudal to this, a standard prokinetic hinge joint position, at the dorsal border of braincase and upper mandible. However, whereas the craniofacial joint in all bucerotiform bird species we examined was only a slender bridge, the helmeted hornbill's joint is exceptionally reinforced. Raycasting analyses revealed high correspondence between the extremely broad joint facets, with reciprocal topographies of braincase and casque fitting like complex puzzle pieces. The result is a joint with a single degree of freedom and limited range of motion, increasing the gape when elevated, but conversely stable when depressed. With the dense network of bony trabeculae in the casque also funneling back to this joint, we infer that the damaging effects of high cranial impact are mitigated, not by dissipating impact energy, but through a skull architecture with a prodigious safety factor.