Search Results (8,201)

The appearance of antibiotic-resistant strains of Helicobacter pylori (H. pylori) is leading to a decreased eradication rate of H. pylori infection. There is an urgent need to find new agents with antimicrobial mechanisms different from those of antibiotics, with therapeutic potential to clear colonization of H. pylori in the stomach. Some antimicrobial peptides (AMPs) possess bactericidal activity by enhancing the permeability of the outer membrane and damaging the integrity of the cell membrane. Bacteria are not susceptible to drug resistance through this antimicrobial mechanism. In this study, 28 short peptides containing 12 amino acid residues were designed based on nine amino acid fragments (KRIVQRIKD) from human cathelicidin LL-37, which is stable in gastric juice, and 3 amino acids were added at the C-terminus of the peptide. These designed peptides were not digested and degraded by pepsin at low pH values. The peptides were predicted using the online tool platform. Then, the strongest antimicrobial peptide, named SAMP-12aa (KRIVQRIKDVIR), was screened from 28 short peptides. Further studies found that SAMP-12aa retained anti-H. pylori activity after incubation in simulated gastric juice. The MIC and MBC of SAMP-12aa were 8 μg/mL and 32 μg/mL, respectively. SAMP-12aa showed good bactericidal kinetics. SAMP-12aa was found to have cell selectivity, penetrating and damaging bacterial cell membranes and exhibiting almost no toxicity to human cells at a relatively high concentration (128 μg/mL). Regulatory T (Treg) cells express CD25^High with immunosuppressive activity that induces immune tolerance in response to H. pylori. Molecular docking prediction revealed that SAMP-12aa could target the active center of Foxp3. Flow cytometry analysis revealed that SAMP-12aa can inhibit Foxp3 activity and downregulate CD25 protein expression on CD4⁺ T cells, thereby reducing the development and differentiation of CD4⁺Foxp3⁺CD25^High Treg cells with immunosuppressive effects. Further research revealed that the levels of the cytokine interferon-γ (IFN-γ), which activates CD8⁺ T-cell activity, were significantly elevated, and the levels of transforming growth factor-β (TGF-β), which inhibits CD8⁺ T-cell activity, were significantly reduced. The results of this study reveal that SAMP-12aa not only possesses antibacterial activity but also has immunomodulatory effects. Full article

RNA origami enables genetically encoded, single-stranded RNA nanostructures that can self-assemble through co-transcriptional folding and are increasingly deployed as scaffolds for biosensing, synthetic biology, and nanomedicine. A recurring practical bottleneck is scalable, solution-phase readout of whether a designed scaffold has reached its intended base-paired architecture, whether it undergoes slow maturation or kinetic trapping, and how its stability is distributed across motifs. Here, we adapt microfluidic modulation spectroscopy (MMS) as a label-free structural biosensor for RNA folding by exploiting the rich 1760–1600 cm⁻¹ vibrational fingerprints of RNA bases and base pairs. MMS alternates between sample and composition-matched buffer measurements in a microfluidic transmission cell to automatically subtract the solvent background, enabling high-quality spectral measurement from microliter volumes under native solution conditions. Using a six-helix-bundle-with-clasp (6HBC) RNA origami as a model, we established an analysis workflow (baselined second derivative and constrained deconvolution) to quantify paired versus unpaired populations. Thermal ramping resolves multiple unfolding events and yields an unfolding barcode that differs between young and mature ensembles. Importantly, MMS tracks post-transcriptional maturation from a kinetically trapped young conformer toward a more compact, base-paired mature state, consistent with prior cryo-EM/SAXS observations for 6HBC RNA origami. Together, these results position MMS as a rapid, automated, and scalable complement to high-resolution structure determination for engineering dynamic RNA origami biosensors. Full article

Gel polymer electrolytes (GPEs) typically suffer from sluggish kinetics and interfacial instability at elevated temperatures and high voltages. Herein, 3-(trifluoromethyl)-1H-1,2,4-triazole (TTA) is employed to construct an ultrathin (~25 μm), robust, and homogeneous GPE. TTA acts as a molecular bridge, significantly improving compatibility between the PVDF-HFP (Poly(vinylidene fluoride-co-hexafluoropropylene)) matrix and LLZTO (Li_6.4La₃Zr_1.4Ta_0.6O₁₂) fillers to create continuous ion-conducting pathways. Consequently, the TTA-GPEs exhibits high ionic conductivity (0.267 mS cm⁻¹ at room temperature), low activation energy (0.181 eV), and an increased lithium-ion transference number (0.425). Advanced surface analysis reveals that TTA preferentially reacts to form a dense, gradient hierarchical interphase (solid electrolyte interphase/cathode electrolyte interphase, SEI/CEI) enriched with inorganic species (LiF, Li₃N, and Li₂S) on the inner side. This architecture suppresses parasitic reactions and lithium dendrite growth. Accordingly, NCM811(LiNi_0.8Co_0.1Mn_0.1O₂)//Li batteries with TTA-GPEs demonstrate stable cycling at 80 °C and 1C, retaining 57.68% capacity after 125 cycles—significantly outperforming benchmarks. This study offers a molecular engineering strategy to simultaneously optimize bulk transport and interfacial stability for high-energy-density solid-state batteries. Full article

The growing pollution caused by plastics with slow degradation kinetics is demanding the search for biodegradable alternatives. Starch-based films are a promising option, but their practical application may be limited by their potential susceptibility to rapid ultraviolet (UV) exposure degradation. This study evaluates the effect of prolonged UV-C irradiation (254 nm, 168 h) on plasticizer-free films derived from the starch of an Ecuadorian potato Solanum tuberosum (Chola variety). Films formulated at 3% and 5% (w/v) starch were characterized before and after UV exposure. The analysis includes the evaluation of optical, mechanical, and physicochemical properties, along with Fourier Transform Infrared spectroscopy (FTIR) and atomic force microscopy (AFM) for nanoscale surface inspection. UV irradiation increased the opacity of the films but reduced slightly their tensile strength, elongation at break, moisture content, and total soluble matter. In contrast, the elastic modulus remained relatively high. FTIR analysis revealed no significant formation of new functional groups. AFM measurements indicated that irradiation caused only minor nanoscale alterations in the same film regions. These alterations were more pronounced in films with higher starch concentrations. The results demonstrate that UV-C exposure induces minor structural adjustments in plasticizer-free starch films derived from the Chola variety, without compromising their fundamental integrity. Consequently, this work advances the understanding of the environmental stability of these films and supports their potential application as sustainable materials, even in conditions involving UV exposure. Full article

Anticipation allows individuals to prepare actions by predicting upcoming events, yet its influence on motor learning and its practical relevance for rehabilitation remain unclear. This study investigates how anticipation mechanisms shape motor learning and skill acquisition in a virtual leader–follower task and explores their potential for adaptive training. Forty-nine healthy adults performed a joystick-controlled tracking task in virtual reality, following a dynamic leader that was always visible (Control), became invisible at regular intervals (Deterministic Anticipation), or disappeared randomly (Stochastic Anticipation) to elicit anticipatory behavior. Kinematic and kinetic metrics and time-series analysis were used to evaluate synchrony, smoothness, and coordination. Performance improved from baseline to retention, with no distinct differences in final performance between the groups. However, slope-based analyses found that anticipation-based training accelerated learning, especially in the novice subgroup (baseline score < 35), with marked improvements in metrics such as score pause duration, temporal lag, and spatial error. Although participants reached similar final performance levels across protocols, the rate and pattern of learning differed across training protocols. Anticipation accelerates early-stage improvements, with the strongest effects observed in novice participants. The paradigm provides a high-resolution framework for adaptive motor training and assessment. Full article

Potassium superoxide (KO₂) can form during the oxidation of residual potassium in NaK-contaminated cold traps of sodium-cooled fast reactors. Its strong oxidizing nature, combined with limited thermal stability, raises safety concerns during shutdown and maintenance. Here, we integrate first-principles calculations with experiments to clarify the facet stability, temperature-driven surface evolution, and stepwise thermal decomposition of KO₂. Guided by the tetragonal I4/mmm crystal symmetry of bulk KO₂, symmetry-non-equivalent low-index facets and relevant surface terminations were systematically evaluated to identify physically meaningful exposed surfaces. Ab initio molecular dynamics (AIMD) simulations further show that heating induces progressive surface amorphization and enhanced oxygen mobility, accompanied by the emergence of shortened O-O bonds and outward migration of oxygen species. Kinetic analysis using the climbing-image nudged elastic band (CI-NEB) method indicates that oxygen evolution is preferentially mediated by O₂ release rather than atomic oxygen escape. Differential scanning calorimetry (DSC) reveals two endothermic events consistent with sequential decomposition, while X-ray diffraction (XRD) confirms the transformation of KO₂ into K₂O. Collectively, these results provide an atomistic-to-macroscopic understanding of KO₂ decomposition, offering practical guidance for defining safer preheating windows and handling strategies for NaK-contaminated components. Full article

Enrofloxacin (ENR), as a widely used antimicrobial agent in aquaculture, poses potential risks to ecosystems and human health due to its environmental persistence. Therefore, it is of great significance to explore efficient methods for removing ENR from aquaculture wastewater. In this study, a series of shrimp shell-derived aerogel (MBC300–MBC700) were fabricated from Litopenaeus vannamei shells through chemical modification followed by pyrolysis at 300–700 °C, and their adsorption performance and mechanisms toward ENR were systematically investigated. The modified porous materials exhibited a well-developed micro–mesoporous structure, high specific surface area, and abundant surface functional groups. Meanwhile, MBC400 demonstrated the highest adsorption capacity for ENR, reaching 14.56 mg/g, with a corresponding specific surface area of 77.71 m²/g. The adsorption kinetics followed the pseudo-second-order model, and the isothermal data were better fitted by the Freundlich model, indicating a chemisorption-dominated, heterogeneous multilayer adsorption process. Thermodynamic analysis revealed that the adsorption was spontaneous (ΔG < 0) and endothermic (ΔH > 0). In regeneration experiments, 30% ethanol solution achieved the best desorption efficiency for MBC400, with adsorption efficiency remaining above 75% after three cycles. Based on the characterization and adsorption results, adsorption mechanism of ENR on MBC400 was elucidated as a synergistic effect of hydrogen bonding, π–π stacking, electrostatic interaction, and surface complexation. This study provides a novel strategy and theoretical basis for the high-value utilization of shrimp shell waste and for the efficient removal of fluoroquinolone antibiotics from aquaculture effluents. Full article

Regarding the precipitation behavior of Cu particles in steel, conventional studies have primarily focused on isothermal precipitation, which has limitations in characterizing precipitation kinetics under variable temperature conditions. For this purpose, in the present study, the Fe-3%Si-Cu alloy was selected as a model system to systematically investigate the regulation of Cu particle precipitation behavior and associated strengthening effects in a ferrite matrix during continuous heating—a process path that better aligns with practical conditions. The results indicate that, during the continuous heating process, an increase in the heating rate from 10 °C/h to 600 °C/h leads to a significant rise in the peak temperature, from 490.2 °C to 609.7 °C, while the time required to reach the peak temperature decreases substantially, from approximately 9.1 h to 19.6 min. Through TEM microstructure analysis and characterization, it is evident that rapid heating at 500 °C/h significantly promotes the high-density nucleation of B2 and 9R-Cu metastable phases while effectively suppressing particle coarsening. This results in a finely dispersed nano-Cu precipitate phase with an average particle size of 8.21 nm and a number density of 30.35 × 10¹⁰ cm⁻². Under the rapid heating condition of 500 °C/h, the precipitation strengthening contribution of Cu particles reaches 501.86 MPa, significantly higher than the 451.02 MPa observed under the slow heating condition of 50 °C/h. This study, from the perspective of the coupling effect between thermodynamics (driven by undercooling) and kinetics (governed by diffusion), elucidates the kinetic behavior of Cu particle precipitation during continuous heating. It provides a novel fundamental and strengthening theory in the field of ferrite metallurgy for copper-enriched electrical steels and related engineering steels, offering significant insights for further understanding the role of copper in ferrite-based steels. Full article

Background/Objectives: Inclusion complexes among drugs and cyclodextrin-modified polymers are a topic of recent interest in pharmaceutical research and industry as they might expand the solubility, bioavailability, and stability of the guest molecules. Polyurethanes derived from cyclodextrins show some biomedical applications. In this study, two cross-linked polyurethane networks based on hydroxypropyl-β-cyclodextrin (HPβCD) and polyethylene glycols (PEG 2000 or PEG 6000) were synthesized with NCO/OH molar ratio 4.3 and 6.3 by the typical two-step polymerization method. Methods: Inclusion complexes of clotrimazole (CLOT) with two HPβCD-modified polyurethane networks and their corresponding physical mixtures were prepared using kneading methods and physical mixing in a 1:6 weight ratio of CLOT:HPβCD. Results: Obtained prepolymers, previously end-capped with isocyanate groups forming urethane links with HPβCD, which were confirmed by FTIR analysis. TGA results indicate a slight increase in thermal stability of the prepared complexes. The characteristic endothermic peak of the CLOT at around 145.90 °C did not appear in the DSC curve of the drug-loaded inclusion complexes. The XRD patterns of physical mixtures showed specific peaks corresponding to pure clotrimazole. SEM micrographs confirmed an elliptical/spherical- and plate-shaped particles without phase segregation, indirectly confirming that CLOT is not separately present due to inclusion into HPβCD and entrapment into polyurethane networks. Novel complexes PUR2/HPβCD-CLOT-IC and PUR3/HPβCD-CLOT-IC were applied as drug carriers, and diffusion-controlled kinetics of CLOT release were best described using Higuchi model. Conclusions: The obtained in vitro results showed surprisingly slow/prolonged clotrimazole release from modified polyurethane networks due to the significant influence of NCO/OH molar ratio and the chosen polyol soft segments chain length with potential in vivo applications. Full article

Traditional calcium hydroxide (Ca(OH)₂) typically exhibits low specific surface area and reactivity, significantly limiting its efficacy in industrial gas–solid reactions such as flue gas desulfurization and thermochemical energy storage. To address these limitations, this study proposes a two-stage synthesis strategy designed to enhance the surface properties and chemical activity of Ca(OH)₂. The process involves the preparation of high-activity calcium oxide (CaO), followed by controlled hydration using diethylene glycol (DEG). Drawing on established mechanisms from cement chemistry, wherein potassium ions (K⁺) catalyze the decomposition of calcium carbonate (CaCO₃), limestone particles (10–20 mm) were pre-soaked in a 0.1 mol/L potassium nitrate (KNO₃) solution for 48 h prior to calcination. Characterization via X-ray diffraction (XRD), scanning electron microscopy (SEM), and Blaine Air Permeability Method analysis revealed that this pretreatment accelerated decomposition kinetics by inducing surface defects, yielding CaO with a maximum reactivity of 435.7 mL. Subsequent hydration at 80 °C with 70 wt% DEG effectively suppressed particle agglomeration and promoted the formation of thin platelet structures. The resulting Ca(OH)₂ achieved a utilization efficiency of 98.5% and a specific surface area of 43.24 m²/g, demonstrating a robust technical route for fabricating high-performance calcium-based sorbents for environmental and energy applications. Full article

Purpose: Due to the lack of effective local therapeutic strategies for oral squamous cell carcinoma (OSCC), this study aimed to develop a novel gelatin/lignin hydrogel loaded with mesenchymal stem cell (MSC)-derived exosomes enriched in microRNA-185 (miR-185 EV) for intraoral delivery, followed by systematic evaluation of its therapeutic efficacy and underlying molecular mechanisms. Materials and Methods: The gelatin/lignin hydrogel was prepared and subsequently loaded with miR-185 EV. The physicochemical properties of the hydrogel, including microstructure, swelling behavior, chemical composition, and rheological characteristics, were systematically evaluated. Next, the stability, viscosity, biocompatibility, and exosome release kinetics of the hydrogel were further assessed. A 4-nitroquinoline-1-oxide (4NQO)-induced mouse tongue carcinogenesis model was established to assess the in vivo antitumor activity of the hydrogel via intraoral administration. Moreover, a proteomic analysis was conducted to investigate the molecular mechanisms of miR-185 EV on OSCC. Results: The miR-185 EV-loaded gelatin/lignin hydrogel exhibited favorable physicochemical properties, stability, and biocompatibility while prolonging the tissue retention time of miR-185 EV. In vivo antitumor efficacy experiments showed that the miR-185 EV-loaded hydrogel significantly inhibited tumor occurrence and alleviated epithelial dysplasia. Immunohistochemical analyses revealed significant suppression of tumor proliferation and epithelial–mesenchymal transition (EMT) of the hydrogel. Proteomic analysis indicated that miR-185 EV suppressed OSCC progression by downregulating interleukin-1β (IL-1β), consequently inhibiting the NF-κB signaling pathway. Conclusion: The findings demonstrate the successful development of the miR-185 EV-loaded gelatin/lignin hydrogel that represents an effective nanomedicine platform for intraoral drug delivery, providing a promising strategy for the clinical treatment of OSCC. Full article

This study aimed to investigate the influence of the synthesis parameters on the corrosion resistance of 3D-printed Inconel 718 components. Samples were fabricated using laser powder bed fusion (PBF-LB/M) with different angles of inclination. Corrosion tests were conducted by immersion for 1000 h in a 3.5% aqueous NaCl solution at 20 °C and 45 °C, and by the potentiodynamic polarization measurements. Detailed analysis of changes in morphology, chemical composition, and roughness of 3D prints was performed using scanning electron microscopy, combined with energy-dispersive X-ray spectroscopy, and optical profilometry. To quantify the dissolution of alloy components during the long-term measurements, the post-corrosion solutions were analyzed using microwave plasma–atomic emission spectroscopy. The obtained results demonstrate that inclination angle significantly affects corrosion rate and electrochemical kinetics, with measurable differences in mass loss, Icorr values, and surface degradation morphology observed between orientations. The findings indicate that build orientation governs microstructural anisotropy and surface characteristics, which in turn influence corrosion susceptibility. The novelty of this work lies in the systematic and multi-method evaluation of inclination angle as an independent structural parameter controlling corrosion kinetics in PBF-LB/M-fabricated Inconel 718, providing new insight into structure–corrosion relationships in additively manufactured nickel-based superalloys. Full article

This study investigated the impact of the pretreatment of pea plants (Pisum sativum L. Ran 1) for five days by three times higher light intensity (360 μmol m⁻² s⁻¹) than the intensity for their cultivation (120 μmol m⁻² s⁻¹) on the photosynthetic apparatus’s ability to withstand moderately high temperatures. Photosystem II (PSII) performance was assessed by pulse amplitude-modulated (PAM) fluorometry—evaluation of F_v/F_m, Chl fluorescence decrease ratio—R_Fd, excitation pressure on PSII (1 − qP), non-photochemical quenching (NPQ) analysis, and PsbA (D1) abundance. The redox state of P700 was used to examine photosystem I (PSI), and the redox kinetics of P700 was evaluated as an estimate of cyclic electron flow (CEF). The energy distribution and interaction between the two photosystems were assessed by 77 K chlorophyll fluorescence. Diphenylhexatriene (DPH) fluorescence polarization and PsbS accumulation were followed to estimate alterations in thylakoid membrane characteristics. Our data show that pea plants pretreated with a higher level of light intensity showed higher resistance to temperature increase, maintaining R_Fd values similar to control plants, and the effect of high temperature on PSII excitation pressure (1 − qP) was mitigated. A significant difference between the two groups of plants was observed in terms of quantum yields in both types of non-photochemical quenching, with light pretreated plants showing no change in the energy partitioning ratio while the exposure of non-high light pretreated plants to elevated temperatures led to a more significant increase in quantum yield of constitutive non-photochemical quenching. When plants were exposed to higher temperature, the accumulation of PsbS, induced by high light treatment, was accelerated, and stabilization of thylakoid membrane also occurred. A complex mechanism behind the enhanced tolerance to higher temperature includes the reorganization of membrane pigment–protein complexes, which is regulated by the buildup of PsbS and the accompanying redistribution of excitation energy. Full article

Perovskite oxide photoanodes are attractive for alkaline water oxidation but are commonly limited by interfacial recombination and sluggish charge transfer. Here we enhance anisotropic SrTiO₃ (STO) photoelectrodes via Al doping by simple yet effective one-step hydrothermal method and identify an optimal composition at 4% Al. In 0.1 M NaOH (pH 13) under simulated AM 1.5G illumination, 4% Al:STO exhibits 2 times enhancement in photocurrent density and 80% increase in electrochemically active surface area compared with the pristine SrTiO₃, as evidenced by the reduced charge-transfer resistance and enlarged light–dark photocurrent gap. together with a markedly reduced interfacial impedance, indicating accelerated charge extraction and transfer. Band-structure analysis shows a positive shift in flat-band potential and slight band-gap narrowing after Al doping, providing more favorable carrier energetics. Steady-state and time-resolved photoluminescence further demonstrate strong PL quenching and a prolonged carrier lifetime for 4% Al:STO. ECSA analysis suggests increased electrochemically accessible surface sites at the optimal doping level. Overall, moderate Al doping synergistically tunes defects, band energetics, and interfacial kinetics to improve STO photoanodes for solar water splitting. Full article

With the increasing use of modern technologies in interior design, numerous recent studies have made the effects of kinetic-based design techniques on users’ perceptions a crucial topic, and sustainable performance has emerged as essential. From this standpoint, this study uses a space syntax approach to investigate how human behavioral performance in workspaces is affected by kinetic interiors. Three kinetic-based design strategies were employed to evaluate changes in spatial configuration characteristics, and the relevant terminology was adapted to account for the use of kinetic technology. The paper adopts a comparative analysis model to follow these changes using four syntactic measures: integration, choice, connectivity, and clustering coefficient. The proposed evaluation approach is applied to a traditional office building in Port Said, Egypt, showcasing various aspects of kinetic technology in workspaces. The study’s findings elucidate the correlations between design strategies and the resulting spatial characteristics, guiding designers in evaluating the features of each system and facilitating comparisons between them. Finally, the study’s main aim is to propose a three-step design process as a guideline for creating an integrated kinetic technology design, involving the evaluation of the proposed alternatives to achieve the desired spatial characteristics. Full article