Search Results (872)

Extruded polypropylene (PP) films were exposed to cold air plasma treatment, which resulted in significant changes in their bulk properties. The maximal elongation, ultimate tensile strength (UTS), and toughness of the films were increased. The toughness of the films increased from $U_{T0}=(3323\pm 400) \mathrm{M}\mathrm{P}\mathrm{a}$ to $U_{T\_PT}=(4434\pm 400) \mathrm{M}\mathrm{P}\mathrm{a}$, which is due to the growth of both the maximal elongation and the UTS of the plasma-treated samples. We relate the improvement of the mechanical properties of PP to the morphological transformations revealed in the plasma-treated PP films. Plasma treatment of PP samples was also followed by the modification of their surface properties. Plasma treatment resulted in hydrophilization of PP films followed by hydrophobic recovery. The bulk and surface properties of the plasma-treated PP films evolve with time. The following hierarchy of the temporal scales related to the studied relaxation processes is established: ${\tau }_{HR}>{\tau }_{\epsilon }={\tau }_T={\tau }_{UTS}>{\tau }_E$, where ${\tau }_{HR}, {\tau }_{\epsilon }, {\tau }_T, {\tau }_{UTS}$ and ${\tau }_E$ are the time scales of the change in the apparent contact angle (hydrophobic recovery), elongation, toughness, ultimate tensile strength, and Young modulus, respectively. The longest of the relaxation times is related to the surface processes, i.e., hydrophobic recovery. The stress–strain curves of the untreated virgin and plasma-treated PP are well described with the twin-slope linear dependencies. The post-plasma-treatment recovery of the tangent modulus is reported. Cold plasma treatment of polypropylene produces surface oxidation and functionalization, evidenced by the emergence of C–O, C=O, and COOH functionalities. Full article

To address the performance degradation of conventional rare-earth silicate environmental barrier coatings (EBCs) in high-temperature water-oxygen environments, this study developed a novel high-entropy EBC system. The coating with a composition of (Yb_1/5Y_1/5Lu_1/5Er_1/5Ho_1/5)₂Si₂O₇/Si/SiC was prepared via atmospheric plasma spraying. Thermal cycling corrosion tests were conducted at 1400 °C under a 90% H₂O–10% O₂ atmosphere. Results show that after heat treatment, the monosilicate phase content decreased, and the structure stabilized. The coating surface exhibited a ridge-like morphology with pits and microcracks after corrosion. A porous corrosion layer formed at the edges, and the SiO₂ layer thickness increased parabolically from 2.75 μm after 100 cycles to 5.65 μm after 300 cycles. The coating demonstrated excellent corrosion resistance, with degradation initiated by surface thermochemical corrosion, leading to corrosion layer formation and SiO₂ accumulation. This study provides important insights for developing long-life EBCs for aero-engine applications. Full article

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) have been identified as forever chemicals and pose a serious threat to the environment due to their stable C–F bond. The current methods are ineffective or costly for PFAS remediation. In response, this study develops a dielectric barrier discharge (DBD) air plasma system capable of simultaneously treating perfluorooctanoic acid (PFOA)-contaminated wastewater and enhancing waste-activated sludge (WAS) solubilization through the subsequent use of plasma-activated water (PAW). Air plasma achieved 94% PFOA degradation and 32% defluorination within 40 min—substantially outperforming Ar and N₂ plasma—due to the co-generation of hydrated electrons (e_aq⁻), ^•OH, and reactive nitrogen species (RNS). Scavenging experiments confirmed that e_aq⁻ is the primary initiator of C–F bond cleavage, while H₂O₂ and NO₂⁻ synergistically form peroxynitrous acid (ONOOH), further promoting chain-shortening reactions. UPLC-MS identified PFHpA, PFHxA, PFPeA, and PFBA as key intermediates. The air plasma effluent contained high concentrations of NO₂⁻-N and H₂O₂ under acidic conditions, enabling PAW to induce strong oxidative stress on WAS, resulting in significant extracellular polymeric substance (EPS) release (DOC up to 134 mg/L), improved sludge filterability (capillary suction time (CST) reduced by ~85%), and shifts in microbial community. This study presents a dual-functional air plasma approach that enables both PFAS degradation and sludge treatment, improving the overall competitiveness and applicability of plasma technology for advanced wastewater treatment. Full article

Cold atmospheric plasma (CAP) has emerged as a promising anticancer approach because of its ability to selectively eliminate malignant cells. Among the proposed mechanisms of this selectivity, the Bauer theory emphasizes the synergistic action of plasma-derived hydrogen peroxide (H₂O₂) and nitrite (NO₂⁻), leading to the transient generation of primary singlet oxygen (¹O₂). This early event inactivates membrane-bound catalase, allowing tumor cell-derived H₂O₂ and peroxynitrite to initiate a self-amplifying cycle that produces secondary ¹O₂, as a hallmark of CAP selectivity. To test this hypothesis, in this work, we monitored extracellular dissolved oxygen (DO) dynamics in HT-29 colorectal cancer cells treated with an argon plasma jet using time-resolved phosphorescence lifetime spectroscopy. Temporal variations in DO likely reflect the cumulative effect of rapid ¹O₂ production and its reactions with cells. A delayed surge in extracellular ¹O₂ was observed specifically in dying cancer cells within the 10–20 min window predicted by the model. Intracellular ROS imaging confirmed a strong correlation between intracellular ROS, extracellular ¹O₂ dynamics, and viability loss. Together, these results provide mechanistic validation of Bauer’s redox model and suggest that early oxygen dynamics after CAP exposure can serve as predictive markers for treatment efficacy in plasma or photodynamic therapies. Full article

To tailor surface chemistry and wettability for advanced membrane applications, this study investigates PES-, PES–PVP-, and PES–GO-based nanofiber membranes modified through oxygen plasma treatment. The plasma process introduced reactive functional groups, including SO₃H, C=O, and OH, onto the fiber surfaces, converting the membranes from hydrophobic to super-hydrophilic and enhancing their surface reactivity. This modification enabled tunable wettability, allowing controlled adjustment of the membrane’s hydrophilic behavior. Overall, the results demonstrate the effectiveness of plasma engineering in developing versatile nanofiber membranes with customizable surface properties for a wide range of applications. Full article

In this paper, composite structures were fabricated by incorporating silver nanowires (AgNWs) with various metal oxides via the sol–gel method. This approach enhanced the electrical performance of AgNW-based transparent electrodes while simultaneously improving their stability under damp heat conditions and modifying the local medium environment surrounding the AgNW meshes. The randomly distributed AgNW meshes fabricated via drop-coating were treated with plasma to remove surface organic residues and reduce the inter-nanowire contact resistance. Subsequently, a zinc oxide (ZnO) coating was applied to further decrease the sheet resistance (R_sheet) value. The pristine AgNW mesh exhibits an R_sheet of 17.4 ohm/sq and an optical transmittance of 93.06% at a wavelength of 550 nm. After treatment, the composite structure achieves a reduced R_sheet of 8.7 ohm/sq while maintaining a high optical transmittance of 92.20%. The use of AgNW meshes as window electrodes enhances electron injection efficiency and facilitates the coupling mechanism between localized surface plasmon resonances and excitons. Compared with conventional ITO transparent electrodes, the incorporation of the AgNW mesh leads to a 17-fold enhancement in ZnO emission intensity under identical injection current conditions. Moreover, the unique scattering characteristics of the AgNW and metal oxide composite structure effectively reduce photon reflection at the device interface, thereby broadening the angular distribution of emitted light in electroluminescent devices. Full article

Anti-GQ1b antibody syndrome (AGABS) unifies triad-defined Miller Fisher syndrome (MFS), Bickerstaff brainstem encephalitis (BBE), and the ophthalmoplegic variant of Guillain–Barré syndrome (GBS-O) under a post-infectious immune mechanism centered on IgG to disialosyl gangliosides. The spectrum also encompasses triad-minus phenotypes—acute ophthalmoparesis without ataxia, acute vestibular syndrome, optic involvement, and acute sensory-ataxic neuropathy. A molecular-mimicry model with complement-mediated nodal/paranodal dysfunction explains severe early deficits despite bland limb nerve conduction studies (NCSs), the cranial/proprioceptive predilection, and generally favorable treatment responsiveness to immunotherapy. In practice, a serology-first strategy, complemented by targeted electrophysiology—blink and H-reflex testing, and, where feasible, paired SEP–ABR showing a literature-supported dissociation (normal ABR with impaired median-nerve cortical SEPs), which, in our series, was documented in one illustrative BBE case—and by structured neuro-otologic examination, mitigates the “normal-NCS trap” and enables timely treatment. Intravenous immunoglobulin (IVIg) is first-line; plasma exchange (PLEX) is an alternative in severe or IVIg-ineligible cases; and intravenous methylprednisolone (IVMP) may be added selectively for central/optic-weighted phenotypes without routine oral taper. We consolidate actionable diagnostic and therapeutic steps and examine them in an institutional series of 16 consecutive seropositive patients (2015–2025): all were anti-GQ1b-positive with frequent GT1a co-reactivity; most reported an antecedent infection—typically upper respiratory, less often gastrointestinal—within the two weeks before onset; limb NCSs were often nondiagnostic whereas reflex/evoked-potential studies were informative; two required intubation in addition to IVIg; outcomes were generally favorable with early immunotherapy. The practical message: order anti-GQ1b at first contact, pair targeted electrophysiology with neuro-otology, and treat early to exploit reversible nodal/paranodal dysfunction. Full article

Type 2 diabetes mellitus (T2DM) can be traditionally treated by edible and medicinal species rich in flavonoids and triterpenoids known for their metabolic benefits. Cucumis prophetarum L. has shown antioxidant and antidiabetic properties in decoction extracts. Since solvent polarity strongly influences the extraction of secondary metabolites, this study investigated the hydroalcoholic extracts of C. prophetarum L. to explore their chemical composition and insulin-sensitizing potential. Hydroalcoholic extracts from the leaf, stem, and root of C. prophetarum L. were analyzed by UV-Vis spectroscopy, ATR-FTIR, and UHPLC-ESI-QqTOF–MS/MS to profile their secondary metabolites. The insulin-sensitizing potential of each extract was assessed using an in vitro model of palmitic-acid-induced insulin resistance in L6 skeletal muscle cells, followed by Western blot analysis of key insulin-signaling proteins. Flavonoid glycosides such as apigenin-C,O-dihexoside, apigenin-malonylhexoside, and luteolin-C,O-dihexoside were abundant in leaf and stem extracts, while cucurbitacins predominated in the root. MTT assay confirmed that hydroalcoholic stem and root extracts of C. prophetarum L. were non-cytotoxic to L6 myotubes, whereas the leaf extract reduced viability only at higher concentrations. Oil Red O staining revealed a pronounced decrease in lipid accumulation following stem and root extract treatment. Consistently, the stem extract enhanced insulin signaling through the activation of the IRS-1/PI3K/Akt pathway, while the root extract primarily modulated the AMPK–mTOR pathway. Importantly, both extracts promoted GLUT4 translocation to the plasma membrane, highlighting their complementary mechanisms in restoring insulin sensitivity. Hydroalcoholic extracts of C. prophetarum L. alleviate insulin resistance through multiple molecular mechanisms, with bioactivity and composition differing markedly from previously reported in the decoctions, which highlight a promising source of insulin-sensitizing phytochemicals and underscore the importance of solvent selection in maximizing therapeutic potential. Full article

To investigate the biosilicification capabilities of Bacillus mucilaginosus and Bacillus polymyxa, silicon concentrations in supernatants from quartz and calcium silicate cultures were monitored over a 12-day period using inductively coupled plasma optical emission spectrometry (ICP-OES). Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) were employed to evaluate changes in the absorption intensity of Si–O–Si characteristic peaks, crystalline phase transformations in the reaction products, and the microstructural morphology of quartz and calcium silicate before and after microbial leaching. The results show that after leaching with B. mucilaginosus, the dissolved silicon concentration in the quartz supernatant reached a maximum of 73.868 mg/L on day 8. In contrast, following treatment with B. polymyxa, the silicon concentration in the calcium silicate supernatant peaked earlier, at 149.153 mg/L on day 4. After microbial leaching, both substrates exhibited marked changes in the intensity of the infrared absorption peaks at 1071 cm⁻¹ and 1083 cm⁻¹, suggesting the formation of Si–O–R type organosilicon complexes. Iron tailings (containing inert silica) and fly ash (containing active silica) were selected for experimental validation. Following treatment with B. mucilaginosus for desilication over an 8-day period, the activity index of iron tailings increased from 77.83% to 90.51%, while that of fly ash rose from 66.32% to 85.01%. ICP-OES analysis confirmed that under the action of B. mucilaginosus, the trends in silicon concentration and activity index in the supernatant of silica-containing solid wastes, such as iron tailings and fly ash, were consistent with those observed in quartz, thereby demonstrating effective biological desilication. These findings provide novel insights into the development of environmentally sound disposal methods for a wider range of solid waste types. Full article

Applying non-thermal plasma (NTP) to seeds prior to sowing is recognized for its ability to enhance germination and promote plant growth. This study investigated the effects of NTP seed treatment on alfalfa seed surface characterization, germination, growth, and biochemical traits under varying water conditions. NTP modified seed surface properties by decreasing water contact angle, roughening the coat, and reducing O–H/N–H and C–H band intensities, while major functional groups remained intact. Short plasma exposures (<2 min) enhanced germination, whereas prolonged treatment (10 min) reduced viability, indicating embryo sensitivity. In pot experiments, both 1 and 5 min treatments improved fresh and dry weight, stem and root elongation, pigment accumulation, and protein content, particularly under normal and moderate water stress, while extended exposure (10 min) offered limited benefits and could be detrimental under severe drought. Root growth was most responsive, suggesting enhanced water and nutrient uptake. Plasma had modest effects on polyphenols and flavonoids but influenced early physiological responses and antioxidant activity. These findings highlight NTP as a promising seed priming tool to improve alfalfa performance, though further studies are needed to clarify the mechanisms and specific contributions of plasma components. Full article

Low-temperature plasma treatments were applied to barley seeds using a dielectric barrier-stabilized corona discharge operated in ambient air enriched with oxygen or nitrogen to quantify surface chemical modifications and seed wettability. X-ray photoelectron spectroscopy showed that oxygen-enriched plasma produced the strongest oxidation, increasing surface oxygen from 9 ± 5 at% (control) to 24 ± 5 at%, while reducing carbon from 88 ± 5 at% to 76 ± 5 at%. Nitrogen-enriched plasma induced more moderate changes (O: 13 ± 5 at%, C: 85 ± 5 at%) but resulted in clear nitrogen incorporation, with an enhanced N 1s amine/amide component at ~400.8 eV. The hydroxyl O 1s contribution increased from 70% (control) to 82% (oxygen) and 90% (nitrogen), indicating substantial surface hydroxylation. SEM-EDX showed only minor micrometer-scale composition changes and no detectable morphological damage. Raman and ATR-FTIR spectra confirmed that polysaccharide, protein, and lipid structures remained intact, with intensity variations reflecting increased hydrophilicity. Water imbibition kinetics fitted with the Peleg model demonstrated faster initial hydration after plasma exposure, with 1/k₁ increasing from 20.25 ± 1.90 h⁻¹ (control) to 36.70 ± 6.56 h⁻¹ (oxygen) and 38.87 ± 7.57 h⁻¹ (nitrogen), while 1/k₂ remained nearly unchanged. Full article

This study aimed to investigate the effects of dietary manganese deficiency and compare the impact of manganese macroparticles (MnCO₃) and nanoparticles (Mn₂O₃NPs) on bone remodeling and metabolism. Twenty-seven male Wistar rats were divided into three groups (n = 9): control (standard MnCO₃, 65 mg Mn/kg), manganese-deficient, and Mn₂O₃NPs-supplemented (65 mg Mn/kg). After a 12-week feeding period, bone-related markers and gene expression were analyzed in the femur and blood. Mn-deficient rats showed reduced plasma levels of bone-specific alkaline phosphatase (BALP), tartrate-resistant acid phosphatase 5b (TRAP5b), interferon-β (IFN-β), RANKL glycoprotein, 1,25-dihydroxyvitamin D₃ (1,25-(OH)₂D₃), vitamin K₂, and collagen turnover markers (PINP, CTX-1, NTX). Femur levels of BALP, TRAP5b, interferon-γ (IFN-γ), osteonectin, calcitonin, PICP, PINP, and CTX-1 were also decreased. Replacing MnCO₃ with Mn₂O₃NPs increased IFN-γ but lowered IFN-β and 1,25-(OH)₂D₃ levels in plasma. This treatment also decreased the femur level of BALP and calcitonin, and the RANKL:OPG ratio, while increasing the expression level of Sp7 and Ctsk genes. To conclude, our results suggest that manganese deficiency is associated with suppressed bone turnover and altered mineral metabolism. Furthermore, replacing MnCO₃ with Mn₂O₃ nanoparticles did not yield the anticipated benefits for bone remodeling, as evidenced by the observed imbalances in osteogenic and resorptive markers, indicating a need for cautious evaluation of nanoparticle-based supplementation. Full article

Objective: This study aims to engineer a novel nanoparticle formulation for combined tumor therapy, designated as PDA@Mn-siSur-c-NPs, which comprises a polydopamine/manganese dioxide (PDA@MnO₂) core alongside survivin-targeting siRNA and cyclo(RGD-DPhe-K)-targeting moiety. Methods: The PDA@Mn-siSur-c-NPs were constructed and subjected to detailed characterization. Inductively coupled plasma optical emission spectroscopy (ICP-OES) was employed to quantify manganese content. To assess siRNA stability within the system, samples were incubated with 50% fetal bovine serum (FBS) before agarose gel electrophoresis analysis. Additionally, cellular internalization by 4T1 cells and in vitro photothermal conversion efficiency of the formulation were evaluated. ICP-OES was further utilized to investigate the in vivo pharmacokinetics and tissue distribution of manganese. Animal model studies were conducted to assess the anti-breast cancer efficacy of PDA@Mn-siSur-c-NPs in combination with infrared irradiation. Results: The newly developed PDA@Mn-siSur-c-NPs demonstrated superior siRNA protection, reduced toxicity, and high photothermal conversion capacity. When combined with photothermal therapy (PTT), these nanoparticles exerted enhanced synergistic anti-tumor effects. Delivery of survivin siRNA resulted in a significant downregulation of survivin protein expression in tumor tissues. Moreover, magnetic resonance imaging (MRI) confirmed that the nanoparticles possess favorable imaging properties. Conclusions: This research demonstrates that the integration of PDA@Mn-siSur-c-NPs with PTT holds considerable therapeutic promise for improved breast cancer treatment. Full article

Polyethylene (PE) films are widely used as waterproofing materials on the surfaces of metal pipelines. Poor adhesion of PE films to a metal substrate reduces durability, leading to shorter service life and higher economic costs. The current research aims to study the modification of PE films in atmospheric pressure gliding arc plasma (GAP). The adhesion properties of the modified films were investigated using the contact angle method and adhesion work calculations. During the modification process, the GAP treatment duration and deflector nozzle angle of attack were optimized to 10 s and 135°, respectively. It was established that the adhesion work increased from 62.1 to 141.3 mJ/m² after 10 s GAP modification compared to untreated PE. GAP modifying of PE films for 30 s or more is impractical, as the increase in the adhesion work ceases after that. It was found that surface roughness R_max increased by up to 4.1 times after 10 s GAP modification compared with nontreated PE. The PE films acquired hydrophilic properties after plasma modification, due to changes in the polymer surface’s chemical structure. The results of IR spectroscopy studies indicated oxidation of the film surface, an increase in the concentration of surface polar groups (-COOH, OH, C=O), and the formation of double bonds (C=C), which led to improved adhesive properties. A study of the electret properties showed that the observed decline and subsequent stabilization of values occurred within the first 24 h. Mechanical tests indicated improved performance of the GAP-modified PE films compared to the non-treated ones in the PE–mastic–PE and PE–mastic–steel systems. Due to their enhanced contact properties, the modified PE films are of interest as a base material for creating waterproofing materials. Full article

We demonstrate high-performance MOSFETs on β-Ga₂O₃ films grown by plasma-assisted molecular beam epitaxy (PA-MBE). The high crystalline quality of the β-Ga₂O₃ epilayer was confirmed by X-ray diffraction and atomic force microscopy. An optimized CF₄-plasma treatment was employed to introduce fluorine (F) into the near-surface region, effectively suppressing donor-like states. The resulting devices exhibit an ultralow off-state current of 1 × 10⁻⁹ mA/mm and a stable on/off ratio of 10⁵. A controllable positive threshold voltage shift up to +12.4 V was achieved by adjusting the plasma duration. X-ray photoelectron spectroscopy indicates that incorporated F atoms form F–Ga-related bonds and compensate oxygen-related donor defects. Sentaurus TCAD simulations reveal reduced near-surface charge and a widened depletion region, providing a physical explanation for the experimentally observed increase in breakdown voltage from 453 V to 859 V. These results clarify the role of fluorine in modulating surface defect states in PA-MBE β-Ga₂O₃ and demonstrate an effective route for threshold-voltage engineering and leakage suppression in Ga₂O₃ power devices. Full article