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30 pages, 1426 KB  
Article
Effects of Including Partially Destoned Olive Cake in Sheep Diet on Meat Quality and Salami Production
by Giuseppe Maniaci, Riccardo Gannuscio, Cristina Giosuè, Mahmood Ul Hassan, Gabriele Busetta, Elena Franciosi, Raimondo Gaglio, Massimo Todaro and Marco Alabiso
Animals 2026, 16(2), 347; https://doi.org/10.3390/ani16020347 (registering DOI) - 22 Jan 2026
Abstract
The valorization of cull sheep and the incorporation of agro-industrial by-products into animal feeding represent effective approaches to enhancing the sustainability of small ruminant production systems. This study investigated the effects of dietary inclusion of 17% partially destoned olive cake (OC) in the [...] Read more.
The valorization of cull sheep and the incorporation of agro-industrial by-products into animal feeding represent effective approaches to enhancing the sustainability of small ruminant production systems. This study investigated the effects of dietary inclusion of 17% partially destoned olive cake (OC) in the concentrate fed to Valle del Belice ewes on carcass characteristics, as well as on meat and salami quality. A 14-week feeding trial was conducted on 124 animals allocated to a control (CTR) and an experimental (EXP) group, balanced for parity, days in milk, and daily milk yield. At the end of the trial, five animals per group were slaughtered and their meat was processed into three types of salami: 100% sheep meat (SM), 90% sheep meat with 10% beef heifer brisket (HB), and 90% sheep meat with 10% pork backfat (PB). Meat and salami were evaluated for chemical composition, fatty acid profile, polyphenol content, antioxidant capacity, lipid oxidation, microbiological status, textural properties, and sensory characteristics. Dietary OC supplementation resulted in increased carcass weight, separable fat, intramuscular fat content, and monounsaturated fatty acids—particularly oleic acid—along with higher polyphenol levels and antioxidant activity. Salami produced from OC-fed ewes exhibited reduced weight loss during ripening, lower lipid oxidation, an improved MUFA/SFA ratio, and satisfactory sensory attributes. Microbiological analyses indicated a dominance of lactic acid bacteria and coagulase-negative staphylococci, with no pathogenic microorganisms detected. Overall, the inclusion of olive cake in the diet enhanced meat and processed product quality, supporting the valorization of olive oil by-products within circular economy frameworks. Full article
(This article belongs to the Section Animal Products)
38 pages, 7740 KB  
Review
Waterborne Poly(urethane-urea)s for Lithium-Ion/Lithium-Metal Batteries
by Bushra Rashid, Anjum Hanief Kohli and In Woo Cheong
Polymers 2026, 18(2), 299; https://doi.org/10.3390/polym18020299 (registering DOI) - 22 Jan 2026
Abstract
Waterborne polyurethane (WPU) and waterborne poly(urethane-urea) (WPUU) dispersions allow safer and more sustainable manufacturing of rechargeable batteries via water-based processing, while offering tunable adhesion and segmented-domain mechanics. Beyond conventional roles as binders and coatings, WPU/WPUU chemistries also support separator/interlayer and polymer-electrolyte designs for [...] Read more.
Waterborne polyurethane (WPU) and waterborne poly(urethane-urea) (WPUU) dispersions allow safer and more sustainable manufacturing of rechargeable batteries via water-based processing, while offering tunable adhesion and segmented-domain mechanics. Beyond conventional roles as binders and coatings, WPU/WPUU chemistries also support separator/interlayer and polymer-electrolyte designs for lithium-ion and lithium metal systems, where interfacial integrity, stress accommodation, and ion transport must be balanced. Here, we review WPU/WPUU fundamentals (building blocks, dispersion stabilization, morphology, and film formation) and review prior studies through a battery-centric structure–processing–property lens. We point out key performance-limiting trade-offs—adhesion versus electrolyte uptake and ionic conductivity versus storage modulus—and relate them to practical formulation variables, including soft-/hard-segment selection, ionic center/counterion design, molecular weight/topology control, and crosslinking strategies. Applications are reviewed for (i) electrode binders (graphite/Si; cathodes such as LFP and NMC), (ii) separator coatings and functional interlayers, and (iii) gel/solid polymer electrolytes and hybrid composites, with a focus on practical design guidelines for navigating these trade-offs. Future advancements in WPU/WPUU chemistries will depend on developing stable, low-impedance interlayers, enhancing electrochemical behavior, and establishing application-specific design guidelines to optimize performance in lithium metal batteries (LMB). Full article
(This article belongs to the Section Polymer Applications)
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16 pages, 5786 KB  
Article
Advancing Circular Composite Strategies by Vitrimer-Enabled Reuse of Unidirectional Laminates
by Jannick Fuchs, Nico Schuhmann, Jonathan Alms and Christian Hopmann
Polymers 2026, 18(2), 300; https://doi.org/10.3390/polym18020300 (registering DOI) - 22 Jan 2026
Abstract
To efficiently reuse endless fibre-reinforced composites after their life cycle, the recovery of endless fibres including matrix material with subsequent reprocessing in their original state is desirable. Thanks to their covalent adaptive networks, vitrimers offer ideal properties for enabling new repair and circular [...] Read more.
To efficiently reuse endless fibre-reinforced composites after their life cycle, the recovery of endless fibres including matrix material with subsequent reprocessing in their original state is desirable. Thanks to their covalent adaptive networks, vitrimers offer ideal properties for enabling new repair and circular strategies for composites. In order to evaluate the detachability—meaning the separation of single laminate layers—and recycling potential for continuous fibre reinforcement, process routes and quality parameters must be established. In this study, the double cantilever beam test is used to test the adhesion based on the detachment of continuous fibre layers, and the interlaminare fracture toughness of mode I (GIC) is measured as a parameter for the required energy for detachment. It was shown that GIC increases above the vitrimer transition temperature and is higher than for reference specimens with an epoxy matrix. Surface roughness is measured to determine the mechanical and thermal degradation of the chemical network structure and additionally shows fibre cracking and defects in fibre–matrix interfaces. This allows the recycling process to be evaluated up to the production of a second generation, with the aim of identifying the recycling potential of the vitrimer matrix and implementing it for industrial processes. An efficient recycling strategy of the continuous fibre-reinforced vitrimers was thus demonstrated by hot pressing at 190 °C for 45 min, giving vitrimer samples a second life. Full article
(This article belongs to the Section Innovation of Polymer Science and Technology)
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12 pages, 2588 KB  
Article
Low-Odor High-Density Fiberboard Enabled by Supramolecular Interactions in Wood Fibers
by Xia Yu, Zongying Fu, Bo Liu, Xiaoxuan Guo, Yun Lu and Lihong Yao
Polymers 2026, 18(2), 297; https://doi.org/10.3390/polym18020297 (registering DOI) - 22 Jan 2026
Abstract
The development of sustainable wood-based composites has driven increasing interest in formaldehyde-free, low-odor, and recyclable bonding systems. However, achieving high mechanical performance and dimensional stability in high-density fiberboards (HDFs) without synthetic adhesives remains a challenge. Here, we report a two-step strategy combining oxidative [...] Read more.
The development of sustainable wood-based composites has driven increasing interest in formaldehyde-free, low-odor, and recyclable bonding systems. However, achieving high mechanical performance and dimensional stability in high-density fiberboards (HDFs) without synthetic adhesives remains a challenge. Here, we report a two-step strategy combining oxidative pretreatment of wood fibers with supramolecular assembly of tannic acid (TA) and sodium ions (Na+) to fabricate low-odor, recyclable HDF. Oxidation generated abundant carboxyl groups on the fiber surface, enabling strong coordination and hydrogen-bonding interactions between TA and Na+, which constructed robust inter-fiber supramolecular networks without formaldehyde-based adhesives. The resulting HDF exhibited excellent mechanical properties, with an internal bond strength of 3.1 MPa, a modulus of rupture of 49 MPa, and 24 h water thickness swelling of only 12%. Odor and VOC analysis revealed only trace benzene, demonstrating markedly low odor. Furthermore, the reversible nature of Na+-TA interactions allowed efficient fiber separation and recyclability under mild aqueous conditions. This oxidation-assisted supramolecular approach provides a sustainable route for producing high-performance, low-odor, and recyclable fiberboards, offering a viable alternative to conventional polymer-bonded wood composites. Full article
(This article belongs to the Section Polymer Chemistry)
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9 pages, 1688 KB  
Article
Morphological Evolution of Nickel–Fullerene Thin Film Mixtures
by Giovanni Ceccio, Kazumasa Takahashi, Romana Mikšová, Yuto Kondo, Eva Štěpanovská, Josef Novák, Sebastiano Vasi and Jiří Vacik
Crystals 2026, 16(1), 73; https://doi.org/10.3390/cryst16010073 (registering DOI) - 22 Jan 2026
Abstract
Hybrid systems consisting of metal–fullerene composites exhibit intriguing properties but often suffer from thermal instability. With proper control, such instability can be harnessed to enable the formation of sophisticated nanostructures with nanometric precision. These self-organization phenomena are not limited to thermal stimulation alone [...] Read more.
Hybrid systems consisting of metal–fullerene composites exhibit intriguing properties but often suffer from thermal instability. With proper control, such instability can be harnessed to enable the formation of sophisticated nanostructures with nanometric precision. These self-organization phenomena are not limited to thermal stimulation alone but can also be triggered by other external stimuli. In this work, we investigate the morphological evolution of thin films composed of evaporated C60 and sputtered nickel mixtures, focusing on how external stimuli influence both their structural and electrical properties. Thin films were prepared under controlled deposition conditions, and their surface morphology was analyzed using advanced characterization techniques. Progressive changes in film morphology were observed as a function of composition and external treatment, highlighting the interplay between metallic and molecular components. In particular, it was observed that, due to the annealing treatment, the sample undergoes strong phase separation, with the formation of structures tens of microns in diameter and an increase in electrical resistance, exhibiting insulating behavior. These findings provide insights into the mechanisms governing hybrid thin film formation and suggest potential applications in electronic, optoelectronic, and energy-related devices. Full article
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18 pages, 1467 KB  
Article
Integrated Biomimetic 2D-LC and Permeapad® Assay for Profiling the Transdermal Diffusion of Pharmaceutical Compounds
by Ilaria Neri, Craig Stevens, Giacomo Russo and Lucia Grumetto
Molecules 2026, 31(2), 379; https://doi.org/10.3390/molecules31020379 (registering DOI) - 21 Jan 2026
Abstract
A comprehensive two-dimensional liquid chromatography platform (LC × LC) was developed and validated for dermal permeability studies. In this implementation, the two separation dimensions were applied to mimic the layered structure of human skin: a ceramide-like stationary phase in the first dimension ( [...] Read more.
A comprehensive two-dimensional liquid chromatography platform (LC × LC) was developed and validated for dermal permeability studies. In this implementation, the two separation dimensions were applied to mimic the layered structure of human skin: a ceramide-like stationary phase in the first dimension (1D) to simulate the lipid-rich epidermis, and an immobilized artificial membrane (IAM) phase in the second (2D) to emulate the dermis. Experimental conditions were optimised to reflect the microenvironment of the in vivo skin. For validation purposes, 43 pharmaceutical and cosmetic compounds whose transdermal permeability coefficients (log Kp) were known from the scientific literature were selected as model solutes. A good degree of separation was achieved across the whole dataset, and affinity profiles correlated with transdermal passage properties, suggesting that retention within specific chromatographic ranges may be predictive of skin permeation. To complement this approach, mass diffusion measurements were also conducted using Permeapad® 96-well plates and LC was performed on a narrow bore column in MS-friendly conditions. These log Kp values were compared against both in vivo and chromatographic retention data. The combined use of these techniques offers a strategic framework for profiling new chemical entities for their dermal absorption in a manner that is both ethically compliant and eco-sustainable. Full article
(This article belongs to the Special Issue Recent Developments in Chromatographic Applications in Medicine)
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26 pages, 2841 KB  
Article
Mechanistic Insights into Asphalt Natural Aging: Microstructural and Micromechanical Transformations Under Diverse Climates
by Shanglin Song, Xiaoyan Ma, Xiaoming Kou, Lanting Feng, Yatong Cao, Fukui Zhang, Haihong Zhang and Huiying Zhang
Coatings 2026, 16(1), 140; https://doi.org/10.3390/coatings16010140 - 21 Jan 2026
Abstract
Understanding mechanisms of asphalt in the process of natural aging is crucial for predicting its long-term durability and optimizing performance under diverse environmental conditions. Despite its importance, the microstructural and micromechanical changes induced by natural aging remain poorly understood, particularly under varying climatic [...] Read more.
Understanding mechanisms of asphalt in the process of natural aging is crucial for predicting its long-term durability and optimizing performance under diverse environmental conditions. Despite its importance, the microstructural and micromechanical changes induced by natural aging remain poorly understood, particularly under varying climatic influences. This study addresses this gap by analyzing the effects of natural aging on asphalt’s microscopic properties and identifying key indicators that govern its degradation. Asphalt samples were subjected to natural aging across five climatically distinct regions over 6, 12, and 18 months. Atomic force microscopy (AFM) was employed to characterize surface roughness, adhesion forces, and DMT modulus, while correlation analysis and principal component analysis (PCA) were used to identify relationships among micromechanical indicators and streamline the dataset. The results reveal that natural aging induces irreversible transformations in asphalt’s microstructure, driven by the combined effects of temperature, UV radiation, humidity, and oxygen. These processes promote the evolution of “Bee structures,” increase surface roughness, and accelerate phase separation, alongside chemical modifications such as oxidation and polymerization, leading to progressive material hardening and stiffness. Significant regional and temporal variations in adhesion forces and DMT modulus were observed, reflecting the cumulative impact of environmental factors on asphalt’s aging dynamics. Correlation analysis demonstrated strong associations between surface roughness and “Bee structure” area, while mechanical properties such as stiffness and adhesion were largely decoupled from morphological features. Environmental factors interact in complex ways to drive asphalt aging. Humidity enhances adhesion and stiffness via water-induced capillary forces, while temperature reduces surface roughness and adhesion through molecular reorganization. UV radiation accelerates oxidative degradation, promoting surface erosion and stiffness loss, while altitude modulates these dynamics by influencing temperature and UV exposure. Full article
(This article belongs to the Special Issue Advances in Asphalt and Concrete Coatings)
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13 pages, 607 KB  
Article
Phospholipid Profiling: A Computationally Assisted LC-HRMS Approach in Lecithin
by Ana Šijanec and Matevž Pompe
Separations 2026, 13(1), 40; https://doi.org/10.3390/separations13010040 - 21 Jan 2026
Abstract
The use of lecithin as an emulsifier in food supplements has increased in recent years. However, successful formation of liposomes or micelles requires an appropriate mixture of phospholipids in lecithin. To evaluate the emulsification properties of lecithin for food supplements, a reliable analytical [...] Read more.
The use of lecithin as an emulsifier in food supplements has increased in recent years. However, successful formation of liposomes or micelles requires an appropriate mixture of phospholipids in lecithin. To evaluate the emulsification properties of lecithin for food supplements, a reliable analytical procedure for characterizing phospholipids is necessary. A liquid chromatography–mass spectrometry method was developed to identify phospholipids in lecithin without standard reference materials. For efficient separation of phospholipids before mass spectrometric analysis, a reverse-phase high-performance liquid chromatography method was optimized using a Waters XBridge Protein BEH C4 column. The optimized chromatographic method demonstrated good linearity and precision. Molecular ions were detected in full scan mode to determine accurate mass-to-charge ratios for individual peaks in the chromatogram. A custom Python program was then used to generate a list of possible phospholipid species for each peak based on the measured mass-to-charge ratios. Tandem mass spectrometry was performed to confirm the identity of specific phospholipids by comparing experimental fragmentation patterns with theoretical predictions. Identification of the phospholipids was also confirmed with four commercially available standard reference compounds, demonstrating the reliability of the proposed approach. The developed method offers a practical and cost-effective strategy for identifying phospholipids in complex matrices, especially when standard reference compounds are unavailable. Additionally, it enables targeted selection of standard compounds for future quantitative analyses, making it a valuable tool for comprehensive lipid profiling. Full article
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23 pages, 4678 KB  
Article
RP-DAD-HPLC Method for Quantitative Analysis of Clofazimine and Pyrazinamide for Inclusion in Fixed-Dose Combination Topical Drug Delivery System
by Marius Brits, Francelle Bouwer and Joe M. Viljoen
Methods Protoc. 2026, 9(1), 16; https://doi.org/10.3390/mps9010016 - 21 Jan 2026
Abstract
Reversed-phase high-performance liquid chromatography (RP-HPLC) remains one of the most widely applied analytical techniques in the development and quality control testing of finished pharmaceutical products. The combination of gradient chromatographic methods with diode-array detection (DAD) enhances selectivity, ensuring accuracy and reliability when testing [...] Read more.
Reversed-phase high-performance liquid chromatography (RP-HPLC) remains one of the most widely applied analytical techniques in the development and quality control testing of finished pharmaceutical products. The combination of gradient chromatographic methods with diode-array detection (DAD) enhances selectivity, ensuring accuracy and reliability when testing drugs with diverse chemical properties in a single dosage form (i.e., fixed-dose combination (FDC) products). In this study, an RP-DAD-HPLC method was developed for the quantitative analysis of clofazimine (CFZ) and pyrazinamide (PZA) for inclusion in an FDC topical drug delivery system. Chromatographic separation was achieved using a C18 column (4.6 mm × 150 mm, 5 µm particle size) with gradient elution at 1 mL/min, employing 0.1% aqueous formic acid and acetonitrile (mobile phases). PZA and CFZ were detected at 254 nm and 284 nm, respectively. The method was validated in accordance with ICH Q2 guidelines, assessing specificity (considering interference from solvents, product matrix, and degradation products), linearity (7.8–500.0 µg/mL, r2 = 0.9999), system repeatability (%RSD ≤ 2.7%), and intermediate precision (25–500 µg/mL, %RSD ≤ 0.85%). Method robustness was evaluated using a three-level Box–Behnken design (BBD) with response surface methodology (RSM) to assess the effects of variations in detection wavelength, mobile phase flow rate, and column temperature. Full article
(This article belongs to the Section Biochemical and Chemical Analysis & Synthesis)
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13 pages, 2455 KB  
Article
Structural Characteristics and Direct Liquefaction Performance of Macerals in Yili Coal from Xinjiang
by Yongpan Wang, Xiaohui Li, Lang Liu, Xiaodong Zhou, Ting Liu, Guangjun Li, Jingxian Han and Yourlani Abudurgman
Molecules 2026, 31(2), 375; https://doi.org/10.3390/molecules31020375 - 21 Jan 2026
Abstract
Effectively separating and utilizing macerals based on their properties is crucial for the efficient and high-value utilization of coal. This study enhances the traditional screening method by employing primary and stepwise crushing techniques to separate Yili coal (YLC) into inertinite-rich (YLI) and vitrinite-rich [...] Read more.
Effectively separating and utilizing macerals based on their properties is crucial for the efficient and high-value utilization of coal. This study enhances the traditional screening method by employing primary and stepwise crushing techniques to separate Yili coal (YLC) into inertinite-rich (YLI) and vitrinite-rich (YLV) concentrates. The structural characteristics and direct coal liquefaction (DCL) performance of YLC, YLV and YLI are subsequently studied. The results indicate that YLV exhibits the highest yield of oil, asphaltene and gas, a finding closely linked to its elevated content of highly active functional groups and its long aliphatic and bridge chains. Furthermore, the liquefaction oil from YLV contains the highest content of alkanes and phenols, which is attributed to its high content of aliphatic hydrocarbons and phenolic hydroxyl groups. In contrast, YLI exhibits the lowest product yield relative to YLC and YLV, with the highest contents of aromatics, esters, and ketones in its oil, due to its high contents of aromatic and carbonyl carbon. The separation, structural characteristics and DCL studies of macerals from Yili coal offer valuable insights for the efficient separation and utilization of macerals. Full article
(This article belongs to the Section Molecular Structure)
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15 pages, 3939 KB  
Article
Super-Hydrophobic Polyurethane/Activated Biochar Composites with Polydimethylsiloxane Coating for High-Efficiency Organic Liquid Uptake
by Rafik Elarslene Dra, Badra Mahida, Malika Medjahdi, Belaid Mechab, Nadia Ramdani and Dominique Baillis
Materials 2026, 19(2), 415; https://doi.org/10.3390/ma19020415 - 21 Jan 2026
Abstract
The aim of this work is to develop structurally enhanced and highly hydrophobic polyurethane (PU) foams for the efficient remediation of liquid organic pollutants. For this purpose, PU foams were modified with renewable activated biochar derived from marine algae (AC) and a hydrophobic [...] Read more.
The aim of this work is to develop structurally enhanced and highly hydrophobic polyurethane (PU) foams for the efficient remediation of liquid organic pollutants. For this purpose, PU foams were modified with renewable activated biochar derived from marine algae (AC) and a hydrophobic polydimethylsiloxane (PDMS) coating, producing four systems: pristine PU, PU-AC, PU/PDMS, and the hybrid PU-AC/PDMS composite. The study evaluates how AC incorporation and PDMS surface functionalization influence the microstructure, chemical composition, wettability, thermal stability, and sorption behavior of the foams. SEM images revealed progressive reductions in pore size from 420 ± 80 μm (PU) to 360 ± 85 μm (PU-AC/PDMS), with AC introducing heterogeneity while PDMS preserved open-cell morphology. FTIR confirmed the presence of urethane linkages, carbonaceous structures, and PDMS siloxane groups. Surface hydrophobicity increased markedly from 88.53° (PU) to 148.25° (PU-AC/PDMS). TGA results showed that PDMS improved thermal stability through silica-rich char formation, whereas AC slightly lowered degradation onset. Sorption tests using petroleum-derived oils and hydrophobic organic liquids demonstrated a consistent performance hierarchy (PU < PU/PDMS < PU-AC < PU-AC/PDMS). The ternary composite achieved the highest uptake capacities, reaching 44–56 g/g for oils and up to 35 g/g for hydrophobic solvents, while maintaining reusability. These findings demonstrate that combining activated biochar with PDMS significantly enhances the functional properties of PU foams, offering an efficient and sustainable material for oil–water separation and organic pollutant remediation. Full article
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19 pages, 9557 KB  
Article
The Effect of Thermal Annealing on Optical Properties and Surface Morphology of a Polymer: Fullerene- and Non-Fullerene-Blend Films Used in Organic Solar Cells
by Bożena Jarząbek, Muhammad Raheel Khan, Barbara Hajduk, Andrzej Marcinkowski, Paweł Chaber, Adrian Cernescu and Yasin C. Durmaz
Polymers 2026, 18(2), 280; https://doi.org/10.3390/polym18020280 - 20 Jan 2026
Abstract
The optical properties, electronic structure and morphology of thin films of the polymer donor PTB7-Th blended with either the fullerene acceptor PC70BM or the non-fullerene acceptor ZY-4Cl were systematically investigated to evaluate their annealing-induced evolution. Thin films were characterized using UV–Vis–NIR absorption spectroscopy, [...] Read more.
The optical properties, electronic structure and morphology of thin films of the polymer donor PTB7-Th blended with either the fullerene acceptor PC70BM or the non-fullerene acceptor ZY-4Cl were systematically investigated to evaluate their annealing-induced evolution. Thin films were characterized using UV–Vis–NIR absorption spectroscopy, spectroscopic ellipsometry, ATR-FTIR spectroscopy, atomic force microscopy (AFM), and nano-IR analysis. In situ stepwise thermal annealing revealed distinct changes in absorption edge parameters, indicating thermally induced modifications in the electronic structure of the blend films. Ellipsometric analysis showed that elevated temperatures significantly affect the refractive index and extinction coefficient spectra. AFM measurements demonstrated markedly different surface morphology evolution for the two blend systems, with pronounced needle-shaped crystallites formation observed in PTB7-Th:ZY-4Cl films after annealing at 100 °C. Nano-IR characterization identified these crystallites as predominantly PTB7-Th, indicating phase separation driven by thermal treatment. The combined optical and structural results reveal distinct annealing-induced changes in the blend. Finally, BHJ solar cells, based on PTB7-Th:PC70BM and PTB7-Th:ZY-4Cl active layers, were fabricated, and their photovoltaic response was demonstrated. Full article
(This article belongs to the Special Issue Polymeric Materials for Solar Cell Applications)
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17 pages, 1242 KB  
Article
From Nature to Synthesis and Vice Versa: Costic Acid Analogs with Acaricidal Activity Against the Bee Parasite Varroa destructor
by Eugenia Papastefanaki, Apostolos Spyros, Demosthenis Isaakidis, Maria Kallivretaki, Despoina Moraiti, Napoleon C. Stratigakis, Demetrios Ghanotakis and Haralambos E. Katerinopoulos
Plants 2026, 15(2), 310; https://doi.org/10.3390/plants15020310 - 20 Jan 2026
Abstract
The species Inula helenium belongs to the genus Inula (Asteraceae) and exhibits antibacterial and anti-inflammatory properties. It is used in respiratory and skin diseases. Its bioactivity is attributed to its eudesmanolide components, mainly to alantolactone and isoalantolactone. These components were isolated in high [...] Read more.
The species Inula helenium belongs to the genus Inula (Asteraceae) and exhibits antibacterial and anti-inflammatory properties. It is used in respiratory and skin diseases. Its bioactivity is attributed to its eudesmanolide components, mainly to alantolactone and isoalantolactone. These components were isolated in high purity from the plant’s dried roots, either via multiple column chromatography separations or via repeated recrystallization. Two more eudesmanolides structurally similar to their parent compounds were isolated, namely 11,13-dihydro-alantolactone and 11,13-dihydro-isoalantolactone. The secondary metabolites and their derivatives were characterized in detail, for the first time, via NMR spectroscopy, GC-MS, and HRMS. Synthetic modification of the natural component structure was considered necessary for structure–activity relationship studies and biological tests. Thus, each compound was converted to its nitrile and then to the corresponding acid, or to its azide derivative and then corresponding amine. Antioxidant studies were conducted on the parent compounds, their derivatives, and the methanolic and hexane plant extracts using the DPPH radical method. The study revealed a strong antioxidant capacity of the methanolic extract. Acaricidal studies of both natural products and synthetic analogs against Varroa destructor and the comparison of their activity with the parent natural product costic acid, as well as one of its synthetic congeners, indicated that the “from nature to synthesis and vice versa” approach led to active compounds as well as to meaningful conclusions regarding the “pharmacophore” groups in the structural framework of the acaricides. Full article
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13 pages, 780 KB  
Article
Jordan Curves: Ramsey Approach and Topology
by Edward Bormashenko
Mathematics 2026, 14(2), 351; https://doi.org/10.3390/math14020351 (registering DOI) - 20 Jan 2026
Abstract
We develop a topological-combinatorial framework applying classical Ramsey theory to systems of arcs connecting points on Jordan curves and their higher-dimensional analogues. A Jordan curve Λ partitions the plane into interior and exterior regions, enabling a canonical two-coloring of every arc connecting points [...] Read more.
We develop a topological-combinatorial framework applying classical Ramsey theory to systems of arcs connecting points on Jordan curves and their higher-dimensional analogues. A Jordan curve Λ partitions the plane into interior and exterior regions, enabling a canonical two-coloring of every arc connecting points on Λ according to whether its interior lies in Int(Λ) or Ext(Λ). Using this intrinsic coloring, we prove that any configuration of six points on Λ necessarily contains a monochromatic triangle, and that this property is invariant under all homeomorphisms of the plane. Extending the construction by including arcs lying on Λ itself yields a natural three-coloring, from which the classical value R3,3.3=17 guarantees the appearance of monochromatic triangles for sufficiently large point sets. For infinite point sets on Λ, the infinite Ramsey theorem ensures the existence of infinite monochromatic cliques, which we likewise show to be preserved under arbitrary topological deformations. The framework extends to Jordan surfaces and Jordan–Brouwer hypersurfaces in higher dimensions, where interior, exterior, and boundary regions again generate canonical colorings and Ramsey-type constraints. These results reveal a general principle: the separation properties of codimension-one topological boundaries induce universal combinatorial structures—such as monochromatic triangles and infinite monochromatic subsets—that are stable under continuous deformations. The approach offers new links between geometric topology, extremal combinatorics, and the analysis of constrained networks and interfaces. Full article
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17 pages, 2190 KB  
Article
New Strategy Based on Click Reaction for Preparation of 3-Acyl-4-hydroxycoumarin-Modified Silica as a Perspective Material for the Separation of Rare Earth Elements
by Dzhamilya N. Konshina, Ekaterina S. Spesivaya, Ida A. Lupanova, Anton S. Mazur and Valery V. Konshin
Molecules 2026, 31(2), 369; https://doi.org/10.3390/molecules31020369 - 20 Jan 2026
Abstract
The separation of rare earth elements (REEs) with similar chemical properties remains a relevant challenge today, most often addressed using liquid–liquid and solid-phase extraction with various chelating agents. Excellent complexing agents for REEs are 1,3-diketones and their analogs. We have for the first [...] Read more.
The separation of rare earth elements (REEs) with similar chemical properties remains a relevant challenge today, most often addressed using liquid–liquid and solid-phase extraction with various chelating agents. Excellent complexing agents for REEs are 1,3-diketones and their analogs. We have for the first time proposed a method for preparing a material consisting of a covalently immobilized 3-acyl-4-hydroxycoumarin ligand on silica. For its synthesis, we employed a strategy based on the “click” reaction of 3-azidopropyl silica with a propargyl-containing coumarin–chalcone conjugate—this approach is the most tolerant and does not affect the coordinationally active fragment of the ligand. The material was characterized by thermal analysis, IR spectroscopy, and 13C NMR. The potential of the synthesized material for REE preconcentration was demonstrated at pH 5–5.5: high extraction efficiency for Gd(III), Dy(III), Er(III), Eu(III), Sm(III), and Yb(III) was observed, with fast adsorption kinetics (30 min) and extraction degrees of ~98%. Under unified conditions of static and dynamic extraction for Gd(III), Dy(III), Er(III), Eu(III), Sm(III), and Yb(III), affinity series toward the surface were obtained as a function of the distribution coefficient. It was shown that 10-fold molar excesses of Fe(III), Al(III), Cu(II), Ni(II), and Co(II) allow retention of more than 95% extraction for Dy(III) and Er(III). After adsorption of Dy(III) and Er(III), shifts in the carbonyl group absorption bands are visible in the IR spectra of the material, indicating a chelating mechanism of sorption. Additional studies are required for implementation in analytical and preparative REE separation schemes; however, preliminary data show that the material is a highly active adsorbent. Full article
(This article belongs to the Section Materials Chemistry)
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