Search Results (78)

Background: Denture stomatitis (DS) represents an oral fungal infection induced by Candida albicans, impacting approximately 70% of the individuals who use removable acrylic dentures. Researchers suggest that the high level of the Candida species, particularly Candida albicans (C. albicans), is the predominant etiological factor of DS. Consequently, the development of a soft liner with antifungal activity might significantly enhance its therapeutic applicability. This in vitro study evaluates the impact of phosphate bioactive glass reinforced heat-cured acrylic-based soft liner on the candidal activity in this material. Method: Specimens (10 mm × 2 mm disc-like) were required for the selected test; PBG-Sr nano-powder was synthesized and added to the soft liner at percentages of 1 wt.%, 3 wt.%, 5 wt.%, and 7 wt.%. The candidal adherence test was investigated, and characterization was performed by X-ray diffraction analysis, field emission scanning electron microscopy, energy dispersive X-ray spectroscopy mapping, and particle size analysis. The resulting data were analyzed with one-way ANOVA followed by Dunnett’s test. Results: Candidal adherence in the 1 wt.%, 3 wt.%, 5 wt.%, and 7 wt.% PBG-Sr subgroups had decreased values in comparison to the control (0 wt.%), with the 7 wt.% subgroup demonstrating the lowest count of C. albicans (0.027), close to the nystatin group. Conclusions: PBG-Sr can diminish C. albicans adhesion in soft lining materials, and a soft liner containing PBG-Sr (7 wt.%) showed the most effective activity against C. albicans in the soft liner. Soft liners infused with bioactive glass may have the potential to assist those struggling with denture stomatitis, providing patients with enhanced therapeutic qualities. Full article

Blazars are a class of active galactic nuclei characterized by having one of their relativistic jets oriented close to our line of sight. Their broad emission spectrum makes them exceptional laboratories for probing fundamental physics. In this review, we explore the potential impact on blazar observations of three scenarios beyond the standard paradigm: (i) the hadron beam model, (ii) the interaction of photons with axion-like particles (ALPs), and (iii) Lorentz invariance violation. We focus on the very-high-energy spectral features these scenarios induce in the blazars Markarian 501 and 1ES 0229+200, making them ideal targets for testing such effects. Additionally, we examine ALP-induced effects on the polarization of UV-X-ray and high-energy photons from the blazar OJ 287. The unique signatures produced by these models are accessible to current and upcoming instruments—such as the ASTRI Mini Array, CTAO, LHAASO, IXPE, COSI, and AMEGO—offering new opportunities to probe and constrain fundamental physics through blazar observations. Full article

Metals are essential for the physiological and biochemical processes in the human brain. However, their accumulation can cause neurotoxic effects, including the generation of reactive oxygen species and structural changes in biomolecules. This study aimed to assess the presence and distribution of metals in the human globus pallidus internus using Particle-Induced X-ray Emission (PIXE) and Scanning Electron Microscopy with Energy-Dispersive X-ray (SEM-EDX). Post-mortem brain tissue samples from six individuals without clinical neuropathological findings were analysed. PIXE analysis revealed the presence of Fe, Cr, Al, Zn, Pb, and Ca. SEM-EDX analysis provided the qualitative elemental composition of an observed aggregate, revealing C, N, O, Na, Ca, Al, Si, S, K, Mg, Cl, Fe, Ni, and Cr. Our findings suggest that metal accumulation in the brain can result from environmental pollution and protein aggregation, as well as biomineralisation processes that sequester metal ions to mitigate their harmful effects. A deeper understanding of these accumulation pathways could contribute to improved therapeutic strategies for neurological diseases associated with metal toxicity. Full article

Background/Objectives: To evaluate the concentrations of trace elements in tear fluid among athletes using particle-induced X-ray emission (PIXE), and to assess the associations with gender, sports intensity, and nutritional supplement intake. Methods: In this cohort study, 84 athletes engaged in high- or low-intensity sports completed a demographic and supplement-use questionnaire. Tear samples were collected using Schirmer strips and analyzed for elemental composition with PIXE, a high-sensitivity technique suited for small biological samples. Multivariate and nonparametric statistical analyses were used to compare groups. Results: There were 46 males and 38 females, aged 17–63 years (mean 30.21 years). Tear phosphorus, potassium, and sulfur concentrations were higher in women than men and higher in women participating in low-intensity compared to high-intensity sports. Tear concentrations of magnesium were higher in men participating in high-intensity sports compared to low-intensity sports. They were higher in men than women regardless of supplement intake. Iron concentrations were higher in men than women only when neither group was taking supplements. Smoking had a slight inverse relationship to iron values. Iron levels were particularly high in men participating in intense sports and low in smokers. Magnesium supplements were associated with raised magnesium levels in tears. Conclusions: This study demonstrates an association between trace element levels in human tears and gender, sports intensity, and food supplement intake. PIXE enables the evaluation of trace element concentration in tears, which may serve as potential biomarkers for the clinical assessment of athletes’ health. Full article

A typical county for traditional village conservation in China is Songyang County. It is renowned for its ancient rammed earth dwellings, which exhibit a unique microclimate and possess significant historical value. However, high precipitation and acid rain under the subtropical monsoon climate have caused severe surface erosion, including cracking and spalling. This study focuses on traditional rammed earth dwellings in Chenjiapeng Village, Songyang County, combining field surveys, experimental analysis, and microscopic characterization to systematically investigate erosion mechanisms and protection strategies. Techniques, such as drone aerial photography, X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), and microbial diversity detection, were employed to elucidate the anti-erosion mechanisms of gray–green biological crusts on rammed earth surfaces. The results indicate that algal crusts enhance surface compressive strength and shear resistance through macroscopic coverage (reducing raindrop kinetic energy and moisture retention) and microscopic extracellular polysaccharide-cemented soil particles forming a three-dimensional network. However, acidic environments induce metabolic acid release from algae, dissolving cementing materials and creating a “surface protection-internal damage” paradox. To address this, a “transparent film-biofiber-acid inhibition layer” composite biofilm design is proposed, integrating a biodegradable polylactic acid (PLA) mesh, algal attachment substrates, and calcium carbonate microparticles to dynamically neutralize acidic substances, achieving synergistic ecological protection and cultural heritage authenticity. This study provides innovative solutions for the anti-erosion protection of traditional rammed earth structures, emphasizing environmental compatibility and sustainability. Full article

The process of recycling lithium-ion batteries is drawing global attention due to a shortage of critical raw materials (CRMs), a sustainable and environmentally friendly approach that meets the needs of many industries. Characterization is an important step in the recycling of black mass resulting from the processing of a lithium-ion battery at the beginning and the end of the processes because of the complexity of the feed material and to evaluate the process. This research proposes a beneficiation flowchart for the further separation of graphite particles from metal oxides based on the characterization results by combining scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), laser-induced breakdown spectroscopy, laser scattering particle size distribution analysis, X-ray fluorescence (XRF), X-ray diffraction analysis (XRD), inductively coupled plasma–optical emission spectroscopy (ICP-OES), and thermogravimetry–differential thermal analysis (TG/DTA). Based on these characterization results, it is suggested that black mass with coarser particle size (0.2–1 mm) goes to the liberation process for beneficiation of the Al and Cu and black mass with a size range of 0.053–0.2 mm goes to the froth flotation for beneficiation of the Mn, Ni, Fe, and Co. Finally, a black mass with a size range of <0.053 mm goes through the froth flotation after the agglomeration process. Full article

In this review, we present a compilation of results from studies of coffee carried out with accelerator-based analytical techniques employing swift ions. The fundamentals of these techniques are presented in detail. Moreover, different aspects of coffee are discussed, including the analysis of ground and roasted coffee beans, the effects of the drip brewing process on the final beverage, the importance of the water temperature for the extraction of elements during coffee preparation and how chemical markers can help discriminate coffee for forensic purposes. According to the experimental results, a matrix of different coffee types is represented by large amounts of carbon followed by mild amounts of oxygen. Moreover, elemental maps of roasted coffee beans show how the elements are distributed over the scanned area, thus providing valuable information on the co-localization of different elements within the beans. Concerning the drip brewing process, the results suggest that chlorine, potassium and phosphorus are quite soluble in hot water and therefore make their way into the drinking coffee. Moreover, the extraction of elements during the drip brewing process is dependent on the water temperature. The results obtained with ion-based techniques are discussed in perspective with those obtained by other analytical methods, including inductively coupled plasma technique in its various configurations. Advantages and drawbacks of these techniques are discussed. In this way, the present review opens up new possibilities for the analysis of coffee that go beyond traditional analytical techniques. Full article

The purpose of this study was to investigate the reaction mechanism of wulfenite with an aqueous sodium sulfide solution and thereby provide guidance for the sulfidization flotation and sodium sulfide leaching of wulfenite. For this purpose, dissolution/leaching behavior analysis, X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and field-emission scanning electron microscopy (FESEM) were performed. The dissolution/leaching analysis indicated that sodium sulfide can induce the dissolution of PbMoO₄. The XRD and Raman spectra results demonstrated that PbMoO₄ was replaced by PbS at the wulfenite–sodium sulfide solution interface, and the sulfidized wulfenite particles had a PbMoO₄/PbS core–shell structure. The XPS results also indicated the transformation of PbMoO₄ to PbS. The FESEM images showed the growth of PbS nanoparticles on the surface of wulfenite and the dissolution pits after treatment with sodium sulfide solution. These findings showed that wulfenite sulfidization proceeds through an interface-coupled dissolution–precipitation mechanism. In the presence of sodium sulfide solution, the less stable PbMoO₄ dissolves, and the more stable PbS phase precipitates, both of which are coupled at the wulfenite–sodium sulfide aqueous solution interface. Full article

Cobalt toxicity is difficult to detect and therefore often underdiagnosed. The aim of this study was to explore the pathophysiology of cobalt-induced oxidative stress in the brain and its impact on structure and function. Thirty-five wild-type C57B16 mice received intraperitoneal cobalt chloride injections: a single high dose with evaluations at 24, 48, and 72 h (n = 5, each) or daily low doses for 28 (n = 5) or 56 days (n = 15). A part of the 56-day group also received minocycline (n = 5), while 10 mice served as controls. Behavioral changes were evaluated, and cobalt levels in tissues were measured with particle-induced X-ray emission. Brain sections underwent magnetic resonance imaging (MRI), electron microscopy, and histological, immunohistochemical, and molecular analyses. High-dose cobalt caused transient illness, whereas chronic daily low-dose administration led to long-term elevations in cobalt levels accompanied by brain inflammation. Significant neurodegeneration was evidenced by demyelination, increased blood–brain barrier permeability, and mitochondrial dysfunction. Treated mice exhibited extended latency periods in the Morris water maze test and heightened anxiety in the open field test. Minocycline partially mitigated brain injury. The observed signs of neurodegeneration were dose- and time-dependent. The neurotoxicity after acute exposure was reversible, but the neurological and functional changes following chronic cobalt administration were not. Full article

The first experimental results obtained by the ion beam-induced luminescence technique from the ceramic bodies of ancient tiles are reported in this work. The photon emission from the ceramic bodies is related to the starting minerals and the manufacturing conditions, particularly the firing temperature and cooling processes. Moreover, the results indicate that this non-destructive technique, performed under a helium-rich atmosphere instead of an in-vacuum setup and with acquisition times of only a few seconds, presents a promising alternative to traditional, often destructive, compositional characterisation methods. Additionally, by adding other ion beam-based techniques such as PIXE (Particle-Induced X-ray Emission) and PIGE (Particle-Induced Gamma-ray Emission), compositional information from light elements such as Na can also be inferred, helping to also identify the raw materials used. Full article

The emergence of bio-based carbonaceous materials for various applications has attracted significant attention during the last few years. Here, we report a rapid, efficient, and reproducible microwave-assisted synthesis of graphene quantum dots (GQDs) with identical features irrespective of the nature of biomass waste investigated. The synthesized GQDs were fully characterized by X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, transmission electron microscopy, and dynamic light scattering. The nanoparticles displayed narrow sizes of 1–2 nm and high solubility in polar solvents such as water and ethanol. The protocol described herein is advantageous in comparison to dealing with the synthesis of GQDs from biomass waste previously reported since our protocol is faster owing to the use of microwave heating and the avoidance of dialysis for the purification step. Furthermore, in solution, the water-soluble particles showed excitation-dependent photoluminescence ranging from blue to orange emission wavelengths. Interestingly, thin films displayed white-light emission under 325 nm UV-light excitation, while aggregation-induced quenching was usually observed, opening the way for their potential use as a phosphor in white-light-emitting diodes. Full article

The extensive development of nanotechnologies has allowed nanoparticles to impact living systems through different pathways. The effect of single exposure to high concentrations of silver and copper nanoparticles (50–200 mg/L) on Vaccinium myrtillus L. under field conditions was investigated. Nanoparticle uptake in different segments of Vaccinium myrtillus L. was assessed by applying inductively coupled plasma–atomic emission spectroscopy and a particle-induced X-ray emission technique. Copper nanoparticles mainly accumulated in the roots and leaves, while silver nanoparticles showed a higher affinity for the roots and berries. The nanoparticles’ effects on the pigments and antioxidant activity of the plant’s leaves were also evaluated. The possible human health risk associated with the consumption of nanoparticle-contaminated berries was assessed. The results indicated that the consumption of berries contaminated with nanoparticles presented a low risk for human health. Full article

One of the most recognized decorations of the pick-up technique is the millefiori glass, which has been commonly attributed to Venetian production. However, Portugal is the country where the largest known assemblage of this type of glass artefact has been studied and published. In this work, two important archeological contexts were selected: (1) Santa Clara-a-Velha monastery (SCV) and (2) São João de Tarouca monastery (SJT). The fragments selection was made based on the diversity of decorative motifs, colors, and original forms that has been associated with Portuguese production. The compositional characterization was conducted by performing micro-particle-induced X-ray emission (µ-PIXE) mapping, which facilitated the visualization of the distribution of different oxides across the different glass layers and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to obtain the major, minor, and trace elements composition, including rare earth elements (REEs) to determine which kind of raw materials were used. Additionally, µ-Raman spectroscopy was employed to investigate the opacifiers, while UV–Visible spectroscopy was used to study which chromophores are presented in the glass samples. All the analyzed glass layers can be considered to be of a soda–lime–silica type, and four different geological patterns (from GP1 to GP4) were detected and reported. This result can indicate that these objects were made by using silica sources taken from four different geological settings. Interestingly, the GP3 represents about 41% of the analyzed glass fragments and is compatible with the pattern detected in some production wastes found in two different archeological contexts located in Lisbon, which reinforces the veracity of the theory that this GP can be attributed to a Portuguese production. On the other hand, GP1 was probably attributed Granada provenance. Full article

Mesoamerican nephropathy (MeN) is a non-traditional chronic kidney disease in some areas of Mesoamerica. The health risk from nephrotoxic metals, such as arsenic (As), lead (Pb), mercury (Hg), vanadium (V), cadmium (Cd), rubidium (Rb), chromium (Cr), and nickel (Ni), was assessed in drinking water and soils. These metals, even at low concentrations, have the capacity to induce epigenetic damage and a nephrotoxic effect. The quantification of metals in soils was made through X-ray fluorescence spectrometry (XRF) and inductively coupled plasma optical emission spectrophotometry (ICP-OES), while the quantification of metals in water was carried out through inductively coupled plasma mass spectrometry (ICPMS) and atomic absorption (AA) spectrometry. The levels of As, Hg, Cd, and V in water were within the permissible limits, whereas Pb was found to be double and triple the value recommended by the World Health Organization. The non-carcinogenic risk from As in soil was evaluated using the Hazard Index (HI), and the route of ingestion was found to be the most important route. The results indicate that consuming water or ingesting soil particles with Pb and As poses a health risk to humans. Therefore, these findings identify the presence of toxicants in an exposure scenario and justify further research into these metals in people and the analysis of exposure routes. Full article

In order to improve dispersibility, polymerization characteristics, chemical stability, and magnetic flocculation performance, magnetic Fe₃O₄ is often assembled with multifarious polymers to realize a functionalization process. Herein, a typical three-dimensional configuration of hyperbranched amino acid polymer (HAAP) was employed to assemble it with Fe₃O₄, in which we obtained three-dimensional hyperbranched magnetic amino acid composites (Fe₃O₄@HAAP). The characterization of the Fe₃O₄@HAAP composites was analyzed, for instance, their size, morphology, structure, configuration, chemical composition, charged characteristics, and magnetic properties. The magnetic flocculation of kaolin suspensions was conducted under different Fe₃O₄@HAAP dosages, pHs, and kaolin concentrations. The embedded assembly of HAAP with Fe₃O₄ was constructed by the N–O bond according to an X-ray photoelectron energy spectrum (XPS) analysis. The characteristic peaks of –OH (3420 cm⁻¹), C=O (1728 cm⁻¹), Fe–O (563 cm⁻¹), and N–H (1622 cm⁻¹) were observed in the Fourier transform infrared spectrometer (FTIR) spectra of Fe₃O₄@HAAP successfully. In a field emission scanning electron microscope (FE-SEM) observation, Fe₃O₄@HAAP exhibited a lotus-leaf-like morphological structure. A vibrating sample magnetometer (VSM) showed that Fe₃O₄@HAAP had a relatively low magnetization (Ms) and magnetic induction (Mr); nevertheless, the ferromagnetic Fe₃O₄@HAAP could also quickly respond to an external magnetic field. The isoelectric point of Fe₃O₄@HAAP was at 8.5. Fe₃O₄@HAAP could not only achieve a 98.5% removal efficiency of kaolin suspensions, but could also overcome the obstacles induced by high-concentration suspensions (4500 NTU), high pHs, and low fields. The results showed that the magnetic flocculation of kaolin with Fe₃O₄@HAAP was a rapid process with a 91.96% removal efficiency at 0.25 h. In an interaction energy analysis, both the U_DLVO and U_EDLVO showed electrostatic repulsion between the kaolin particles in the condition of a flocculation distance of <30 nm, and this changed to electrostatic attraction when the separation distance was >30 nm. As Fe₃O₄@ HAAP was employed, kaolin particles could cross the energy barrier more easily; thus, the fine flocs and particles were destabilized and aggregated further. Rapid magnetic separation was realized under the action of an external magnetic field. Full article