Search Results (227)

The main limitations of using a high-temperature drawing approach to tailor poly-l-lactide (PLLA) crystallization and molecular orientation for ultrasound-active piezoelectric structures stem from the intrinsic properties of the processed polymer, including low melting/softening elasticity and slow crystallization kinetics. Here, we found that applying different contacting layers, including polytetrafluoroethylene (PTFE) (as Teflon and Teflon S), cellulose (Paper) or polyimide (Kapton) deposited at the surface of PLLA, significantly affects the drawing process and tailors its oriented crystallization and molecular chain orientation. Consequently, the contacting layers contribute to the piezoelectric properties of PLLA (alone or with added morphologically anisotropic hydroxyapatite (HAp) filler), affecting its activation via ultrasound and generated electro-signal. Human keratinocytes (HaCaT cells) stimulated on these surfaces are shown to receive and respond to the transferred stimuli via the activation of the cytoskeleton and directional migration. The high-temperature (250 °C) drawing approach with contacting layers is a simple, solvent-free and economically viable way of broadening the applications of classical high-temperature drawing, opening new possibilities for further tailoring the piezoelectricity of organic piezoelectrics. Full article

Blueberry (Vaccinium spp.) is a high-value crop due to its growing global demand, recognized nutraceutical properties, and strong linkage with emerging technologies in precision agriculture and postharvest management. To characterize the scientific evolution and intellectual structure, we conducted a bibliometric analysis of 474 documents indexed in Scopus between 1987 and 2025. A systematic search strategy based on taxonomic, agronomic, and technological descriptors was applied, followed by data cleaning and analysis with Bibliometrix and VOSviewer. Performance indicators and science-mapping techniques were used to examine temporal growth, geographical distribution, institutional and author leadership, and thematic structure. Scientific output shows a sustained upward trend with a maximum of 42 articles in 2024, confirming the consolidation of blueberry as a model crop for interdisciplinary research. Research articles represent over 75% of the total (359/474), evidencing an application-oriented and experimentally grounded field. Agricultural and Biological Sciences dominate (382 documents), followed by Engineering (70) and Biochemistry, Genetics, and Molecular Biology (66), reflecting increasing integration of crop management, technological innovation, and food science. Thematic mapping identified five main clusters: physiology and health, plant protection, agronomic management and digitalization, processing and stability of phenolic compounds, and analytical characterization. The analysis reveals gaps in the integration of physiology, food science, and metabolomics, as well as in the biological validation of biomarkers and the study of peripheral Vaccinium species. Overall, the field exhibits a consolidated and sustainability-oriented interdisciplinarity, highlighting opportunities to advance toward more comparable analytical protocols, digital traceability, and artificial-intelligence-assisted decision support along the blueberry value chain. Full article

This study elucidates the interfacial adsorption behavior of a series of short-chain extended anionic surfactants C₈P_xE_yC (sodium ethylhexyl polyoxypropylene x-polyoxyethylene y-carboxylate) on quartz surfaces, with a focus on the regulatory role of polyoxyethylene (EO) and polyoxypropylene (PO) groups. The results indicate that there is a two-stage adsorption process for C₈P_xE_yC molecules on the quartz surface. In the first adsorption stage, C₈P_xE_yC molecules adsorb at the interface primarily via hydrogen bonding with their hydrophobic tails oriented to water and thereby reducing quartz hydrophilicity before the critical micelle concentration (CMC). The second adsorption stage appears at the CMC, and a saturated monolayer forms via hydrogen bonding. When further increasing the concentration, C₈P_xE_yC molecules interact with the pre-adsorbed monolayer by hydrophobic interactions to establish a loose bilayer structure. As the hydrophilic heads of C₈P_xE_yC orient to water, the surface hydrophilicity of quartz enhances after CMC. The PO/EO chain length critically governs the adsorption behavior of C₈P_xE_yC. Specifically, longer PO chains enhance the molecular size and hydrophobicity of C₈P_xE_yC, leading to a decreased saturation adsorption amount. Conversely, longer EO chains improve the hydrophilicity of C₈P_xE_yC, promoting C₈P_xE_yC molecules to stay in water and consequently decreasing the interfacial adsorption amount of C₈P_xE_yC. This structure–activity relationship of C₈P_xE_yC molecules guides the design of extended surfactants for applications requiring precise wettability control. Full article

High-performance spun bionanocomposite fibers, composed of high-molecular-weight chitosan (HMW), low-molecular-weight chitosan “oligomers” (LMW), and cellulose nanofibers (CNFs), were successfully fabricated via gel spinning of viscous aqueous chitosan (CHI) based formulations into a NaOH coagulation bath. The X-ray diffraction (XRD) analysis revealed that the incorporation of cellulose nanofibers contributed to enhance crystallinity of chitosan in spun fibers. The spinning process, which comprised sequential acidic solubilization, basic neutralization, stretching, and drying steps, produced chitosan/CNF composite fibers with high crystallinity, further enhanced by the incorporation of low molecular weight chitosan. The cellulose nanofibers seem to promote CHI crystallization, by acting as nucleation sites for the nucleation and growth of chitosan crystals, with those latter of LMW further enhancing crystallization and orientation due to higher mobility of shorter polymer chains. Two-dimensional XRD patterns demonstrated the preferential alignment of both CNFs and chitosan crystals along the fiber axis. Increasing the proportion of short-chain chitosan led to a reduction of the viscosity of collodion, facilitating the spinning of solutions with higher polymer concentrations. The X-ray diffraction (XRD) analysis revealed that the addition of low-molecular-weight chitosan (LMW), with an intermediate molecular weight Mw of ~4.4 × 10⁴ g/mol, produced the most significant improvements in the crystallinity index (CrI) and orientation. This structural enhancement corresponded to superior mechanical properties like Young’s modulus, yield stress σ_y, and stress-at-break σ_b of the processed composite fibers. By incorporating that intermediate molecular weight chitosan, a Young’s modulus as high as 20 GPa was achieved for the spun composite fibers, which was twice higher than the modulus of around 10 GPa obtained by adding the lowest molecular weight chitosan of Mw ~ 2.9 × 10⁴ g/mol in the composite, and largely above the modulus of around 5 GPa obtained for fiber just spun with chitosan without incorporation of cellulose nanofibers. Full article

To describe unusual findings and management of neuroretinitis in patients with cat scratch disease (CSD), their functional outcome after a case-oriented treatment was anaylsed, and the current literature was reviewed. A retrospective monocentric case series and a literature review. Review of medical records, multimodal imaging, and literature review. Five patients (four females and one male) with a mean age of 29.75 years (range: 11–71 years) had unusual findings of ocular bartonellosis, including inner retinitis, focal choroiditis, retinal microaneurysms, and bilateral sectorial optic nerve swelling. Bartonella-related ocular infections were not limited to the posterior segment of the eye. Molecular tests, such as polymerase chain reaction (PCR), showed that elevated markers of IgG titers were used and were positive in the aqueous humour of one patient. Reference to the use of intravitreal treatment in one of the cases was useful. Case-oriented management is associated with improvement in visual acuity, retinal, and choroidal lesions. The range of ocular signs of Bartonella infection could be extended. Molecular tests, such as PCR, are useful diagnostic approaches in the diagnosis of posterior uveitis. Treatment could require intravitreal antibiotic injections in unusual ocular bartonellosis. Full article

The crystal structure of kuliokite-(Y), Y₄Al(SiO₄)₂(OH)₂F₅, has been re-investigated using the material from the type locality the Ploskaya Mt, Kola peninsula, Russian Arctic. It has been shown that in contrast to previous studies, the mineral is monoclinic, Im, with a = 4.3213(1), b = 14.8123(6), c = 8.6857(3) Å, β = 102.872(4)°, and V = 541.99(3) ų. The crystal structure was solved and refined to R₁ = 0.030 on the basis of 3202 unique observed reflections. The average chemical composition determined by electron microprobe analysis is (Y_2.96Yb_0.49Er_0.27Dy_0.13Tm_0.07Lu_0.05Ho_0.05Gd_0.01Ca_0.01)_Σ4.04Al_0.92Si_2.04O₈-[(OH)_2.61F_4.42]_Σ7.03; the idealized formula is (Y,Yb,Er)₄Al[SiO₄]₂(OH)_2.5F_4.5. The crystal structure of kuliokite-(Y) contains two symmetrically independent Y sites, Y1 and Y2, coordinated by eight and seven X anions, respectively (X = O, F). The coordination polyhedra can be described as a distorted square antiprism and a distorted pentagonal bipyramid, respectively. The refinement of site occupancies indicated that the mineral represents a rare case of HREE fractionation among two cation sites driven by their coordination numbers and geometry. In agreement with the lanthanide contraction, HREEs are selectively incorporated into the Y2 site with a smaller coordination number and tighter coordination environment. The strongest building unit of the structure is the [AlX₂(SiO₄)₂] chain of corner-sharing AlX₆ octahedra and SiO₄ tetrahedra running along the a axis. The chains have their planes oriented parallel to (001). The Y atoms are located in between the chains, along with the F⁻ and (OH)⁻ anions, providing the three-dimensional integrity of the crystal structure. Each F⁻ anion is coordinated by three Y³⁺ cations to form planar (FY₃)⁸⁺ triangles parallel to the (010) plane. The triangles share common edges to form [F₂Y₂]⁴⁺ chains parallel to the a axis. The analysis of second-neighbor coordination of Y sites allowed us to identify the structural topology of kuliokite-(Y) as the only case of the skd network in inorganic compounds, previously known in molecular structures only. The variety of anionic content in the mineral allows us to identify the potential existence of two other mineral species that can tentatively be named ‘fluorokuliokite-(Y)’ and ‘hydroxykuliokite-(Y)’. Full article

To stimulate the progress of clean fracturing fluid systems, an innovative erucyl ultra-long-chain gemini surfactant (EUCGS) was devised and manufactured during the course of this study. The target product was successfully prepared via a two-step reaction involving erucyl primary amine, 3-bromopropionyl chloride, and 1,3-bis(dimethylamino)propanediol, with an overall yield of 78.6%. FT-IR and ¹H NMR characterization confirmed the presence of C₂₂ ultra-long chains, cis double bonds, amide bonds, and quaternary ammonium headgroups in the product structure. Performance tests showed that EUCGS exhibited an extremely low critical micelle concentration (CMC = 0.018 mmol/L) and excellent ability to reduce surface tension (γCMC = 30.0 mN/m). Rheological property studies indicated that EUCGS solutions gradually exhibited significant non-Newtonian fluid characteristics with increasing concentration, and wormlike micelles with a network structure could self-assemble at a concentration of 1.0 mmol/L. Dynamic rheological tests revealed that the solutions showed typical Maxwell fluid behavior and significant shear-thinning properties, which originated from the orientation and disruption of the wormlike micelle network structure under shear stress. In the presence of 225 mmol/L NaCl, the apparent viscosity of a 20 mmol/L EUCGS solution increased from 86 mPa·s to 256 mPa·s. A temperature resistance evaluation showed that EUCGS solutions had a good temperature resistance at high shear rates and 100 °C. The performance evaluation of fracturing fluids indicates that the proppant settling rate (0.25 cm/min) of the EUCGS-FFS system at 90 °C is significantly superior to that of the conventional system. It features the low dosage and high efficiency of the breaker, with the final core damage rate being only 0.9%. The results demonstrate that the EUCGS achieves a synergistic optimization of high-efficiency interfacial activity, controllable rheological properties, and excellent thermal–salt stability through precise molecular structure design, providing a new material choice for the development of intelligent responsive clean fracturing fluids. Full article

Improving the end-of-life performance of polylactic acid (PLA) for food packaging requires strategies that enhance biodegradability, solubility, and dispersibility without compromising essential material properties. PLA-based films were produced by melt extrusion using polyvinylpyrrolidone (PVP) as a hydrophilic modifier, aiming to enhance the water uptake and affinity of PLA, which may potentially lead to faster environmental degradation. Two PVPs with distinct molar masses at varying concentrations were used to investigate their effects on the structural, thermal, mechanical, optical, and barrier behavior of the films. Thermal analysis revealed a slight depression in glass transition temperature, more evident in blends with low-molecular-weight PVP10, indicating increased chain mobility and partial miscibility. A two-step degradation process with extended thermal decomposition profiles was observed upon the inclusion of PVP. SEM and ATR-FTIR analyses confirmed enhanced dispersion and non-covalent interactions in PVP10-based blends, in contrast to the pronounced phase separation and micro-voids observed in PVP40-based systems. Mechanically, films containing 5 and 10 wt.% of PVP10 retained tensile strength and stiffness, whereas PVP40 led to embrittlement. Optical properties were modified by increasing the PVP content, resulting in greater opacity and color differences, which potentially offer benefits for light-sensitive packaging. Altogether, PLA films containing 5 and 10 wt.% of PVP10 demonstrated the most favorable balance between water affinity-oriented design and packaging-relevant performance. Full article

Background/Objectives: Cows produce antibodies with ultralong CDRH3 segments (ulCABs) that contain a disulfide-stabilized knob domain. This domain is connected to the globular core of the antibody by a β-strand stalk. In the crystal structures, the stalk protrudes from the core in an extended conformation and presents the knob at its distal end. However, the rigidity of this topology has been questioned due to the extensive crystal packing present in most ulCAB crystal structures. To gain more insight into the dynamics of ultralong CDRH3s, we performed a comparative molecular dynamics (MD) study of 19 unique ulCABs. Methods: For all 19 systems, one-microsecond MD simulations were performed in explicit solvent. The analyses included an investigation of the systems’ conformational stability and the dynamics of the knob domain as well as an energetic analysis of the intramolecular knob interactions. Results: The simulations show that the extended stalk–knob conformation observed in the crystal structures is not preserved in solution. There are significant differences in the degree of knob dynamics, the orientations of the knobs, the number of flexible stalk residues, and the frequency of the motions. Furthermore, interactions between the knob and the light chain (LC) of the ulCABs were observed in about half of the systems. Conclusions: The study reveals that pronounced knob dynamics is a general feature of ulCABs rather than an exception. The magnitude of knob motions depends on the system, thus reflecting the high sequence diversity of the CDRH3s in ulCABs. The observed knob–LC interactions might play a role in stabilizing distinct knob orientations. The MD simulations of ulCABs could also help to identify suitable knob fragments as mini-antibodies by suggesting appropriate truncation points based on flexible sites in the stalks. Full article

This study was designed to systematically identify novel umami peptides in lager beer, clarify their molecular interactions with the T1R1/T1R3 receptor, and determine their specific effects on multidimensional sensory attributes. The peptides were characterized by LC-MS/MS combined with de novo sequencing, and 906 valid sequences were obtained. Machine-learning models (UMPred-FRL, Tastepeptides-Meta, and Umami-MRNN) predicted 76 potential umami peptides. These candidates were docked to T1R1/T1R3 with the CDOCKER protocol, producing 57 successful complexes. Six representative peptides—KSTEL, DELIK, DIGISSK, IEKYSGA, DEVR, and PVPL—were selected for 100 ns molecular-dynamics simulations and MM/GBSA binding-energy calculations. All six peptides stably occupied the narrow cleft at the T1R1/T1R3 interface. Their binding free energies ranked as DEVR (−44.09 ± 5.47 kcal mol⁻¹) < KSTEL (−43.21 ± 3.45) < IEKYSGA (−39.60 ± 4.37) ≈ PVPL (−39.53 ± 2.52) < DELIK (−36.14 ± 3.11) < DIGISSK (−26.45 ± 4.52). Corresponding taste thresholds were 0.121, 0.217, 0.326, 0.406, 0.589, and 0.696 mmol L⁻¹ (DEVR < KSTEL < IEKYSGA < DELIK < PVPL < DIGISSK). TDA-based sensory validation with single-factor additions showed that KSTEL, DELIK, DEVR, and PVPL increased umami scores by ≈21%, ≈22%, ≈17%, and ≈11%, respectively, while DIGISSK and IEKYSGA produced marginal changes (≤2%). The short-chain peptides thus bound with high affinity to T1R1/T1R3 and improved core taste and mouthfeel but tended to amplify certain off-flavors, and the long-chain peptides caused detrimental impacts. Future formulation optimization should balance flavor enhancement and off-flavor suppression, providing a theoretical basis for targeted brewing of umami-oriented lager beer. Full article

Understanding the early-stage physical interactions between polymeric membranes and supersaturated salt solutions is crucial for advancing membrane-assisted crystallization (MCr) processes. In this study, we employed molecular dynamics (MD) simulations to investigate the short-term morphological response of an isotactic polypropylene (PP) membrane in contact with LiF solutions at different concentrations (5.8 M and 8.9 M) and temperatures (300–353 K), across multiple time points (0, 150, and 300 ns). These data were used as input for computational fluid dynamics (CFD) analysis to evaluate structural descriptors of the membrane, including tortuosity, connectivity, void fraction, anisotropy, and deviatoric anisotropy, under varying thermodynamic conditions. The results show subtle but consistent rearrangements of polymer chains upon exposure to the hypersaline environment, with a marked reduction in anisotropy and connectivity, indicating a more compact and isotropic local structure. Surface charge density analyses further suggest a temperature- and concentration-dependent modulation of chain mobility and terminal group orientation at the membrane–solution interface. Despite localized rearrangements, the membrane consistently maintains a net negative surface charge. This electrostatic feature may influence ion–membrane interactions during the crystallization process. While these non-reactive, short-timescale simulations do not capture long-term degradation or fouling mechanisms, they provide mechanistic insight into the initial physical response of PP membranes under MCr-relevant conditions. This study lays a computational foundation for future investigations bridging atomistic modeling and membrane performance in real-world applications. Full article

Ferritin nanocages with spherical shells carry proteins or antigens that enable their use as highly efficient nanoreactors and nanocarriers. Mimicking the surface Spike (S) receptor-binding domain (RBD) from SARS-CoV-2, ferritin nanocages induce neutralizing antibody production or block viral entry. Herein, by implementing molecular dynamics simulation, we evaluate the efficiency in the interaction pattern (active or alternative sites) of H-ferritin displaying the 24 S RBDs with host-cell-receptor or monoclonal antibodies (mAbs; B38 or VVH-72). Our constructed nanocage targeted the receptor- or antibody-binding interfaces, suggesting that mAbs demonstrate an enhanced binding affinity with the RBD, with key interactions originating from its variable heavy chain. The S RBD interactions with ACE2 and B38 involved the same binding site but led to divergent dynamic responses. In particular, both B38 chains showed that asymmetric fluctuations had a major effect on their engagement with the Spike RBD. Although the receptor increased the binding affinity of VVH-72 for the RBD, the mAb structural orientation on the nanocage remained identical to its conformation when bound to the host receptor. Overall, our findings characterize the essential pharmacophore formed by Spike RBD residues over nanocage molecules, which mediates high-affinity interactions with either binding partner. Importantly, the ferritin-displayed RBD maintained native receptor and antibody binding profiles, positioning it as a promising scaffold for pre-fusion stabilization and protective RBD vaccine design. Full article

Polytetrafluoroethylene (PTFE) has been widely used as a high-frequency dielectric substrate due to its excellent dielectric properties and thermal stability. However, with its low intrinsic thermal conductivity, PTFE falls short in meeting the escalating heat dissipation demands of high-power density, high-frequency communication systems. Although the thermal conductivity of PTFE composites can be effectively improved by the high thermal conductivity fillers, it is always accompanied by a decline in dielectric properties. Molecular chain ordering is regarded as an effective strategy to improve the intrinsic thermal conductivity of polymers while maintaining dielectric properties. Unfortunately, the conventional preparation methods for ordered molecular chains, such as electrostatic spinning and uniaxial stretching, are not applicable to the preparation of PTFE substrates. In this work, fluorinated graphite (FGi) is employed to induce the in-plane orientation of PTFE molecular chains. As a result, the PTFE composite with 0.5 wt% FGi loading exhibits an in-plane thermal conductivity of 1.21 W·m⁻¹·K⁻¹, six times higher than the in-plane thermal conductivity of pure PTFE. In addition, this composite exhibits a superior dielectric constant of 2.06 and dielectric loss of 0.0021 at 40 GHz. This work introduces a facile method to achieve improved thermal conductivity of PTFE while maintaining its excellent dielectric properties. Full article

This study analyzed the compression isotherms of 7β-alkyl cholic acid derivatives and compared them to those of cholic and deoxycholic acids to elucidate their orientation and molecular interactions (acidic aqueous substrate—pH 2; NaCl concentration—3 M; temperature—T = 298.15 K). It was found that the compression isotherm of the 7β-octyl derivative of cholic acid in the monomolecular layer is most similar to the compression isotherm of deoxycholic acid. In 7β-alkyl derivatives of cholic acid, the hydrophobic interaction energy in their aggregates from a monomolecular film increased with the length of the alkyl chain. However, this energy did not increase linearly with C atoms, suggesting the existence of a conformational equilibrium. In binary mixtures of the tested bile acids and lecithin, only the 7β-octyl derivatives of cholic acid and deoxycholic acid had orientations in which the steroid skeleton had a “vertical” position, i.e., only the C3 OH group was immersed in the aqueous substrate, which resulted in the maximum hydrophobic interaction with lecithin. In 7β-octyl derivatives, part of the octyl chain probably also participated in the interaction with lecithin. In 7β-propyl and 7β-butyl derivatives, C7 alkyl groups sterically shielded the C7 α-axial OH group. However, in the 7β-ethyl derivative the C7 OH group was not additionally sterically shielded, so this derivative, similarly to cholic acid, partially dissolved in the aqueous substrate after the collapse point. Full article

Post-processing plays a vital role in the determination of the final structures and properties of oriented materials. As a sustainable candidate of oil-based poly(ethylene terephthalate), biobased poly(ethylene 2,5-furandicarboxylate) (PEF) reflects great promise in green fiber, film, and packaging applications, but it undergoes poor stress-induced crystallization (SIC) under tensile deformation, necessitating a post-processing technique to improve its crystallinity and stability. Here, the structural evolution of pre-stretched PEF under post heating after uniaxial deformation was monitored by online synchrotron X-ray diffraction/scattering, differential scanning calorimetry, and ex situ infrared spectroscopy. The results delineate the significantly enhanced crystallization of pre-deformed PEF that happened far below its cold crystallization temperature. Through the isochronous analyses of the temperature-dependent evolution of mechanical response, the mesophase, crystal structure, orientation factor, chain conformation, and interchain ═C−H···O═C hydrogen bonding, the molecular mechanisms of microstructural transition and oriented crystallization of pre-drawn PEF under post heating were clarified. This research can enhance the understanding of PEF crystallization in an oriented state and provide guidelines on the structural design and technical control for processing high-performance PEF-based materials. Full article