Search Results (40)

This work presents a Fricke radiochromic gel dosimeter with xylenol orange (XO) and a gelatin matrix modified with sorbitol. The dosimeter, combined with 2D scanning using a flatbed scanner and data processing using dedicated software packages, creates a radiotherapy dosimetry measurement system. The dosimeter reacts to ionizing radiation by changing color as a result of the formation of complexes of Fe³⁺ and XO molecules. It was characterized in terms of thermal and chemical stability and mechanical properties. The presence of sorbitol improved the mechanical and thermal properties of the dosimeter. The dosimeter maintains chemical stability, enabling its use in dosimetric applications, for at least six weeks. The dose–response characteristics of the dosimeter are discussed and indicate a dynamic dose–response of the dosimeter (up to saturation) of about 20 Gy and a linear dose–response of about 12.5 Gy. The following applications of the dosimeter are discussed: (i) as a 2D dosimeter in a plastic container for performing a coincidence test of radiation and mechanical isocenters of a medical accelerator, and (ii) for in vivo dosimetry as a 2D dosimeter alone and simultaneously as a bolus and a 2D dosimeter. Research has shown that the dosimeter has promise in many applications. Full article

Feline infectious peritonitis (FIP), a devastating disease with near-complete mortality, is caused by the feline coronavirus (FCoV) and affects domestic cats worldwide. Herein, we report the development of a reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay incorporating xylenol orange (XO) as a visual indicator for FCoV detection. The assay employed six oligonucleotide primers targeting regions of the nucleocapsid (N) gene. Under optimized conditions (65 °C, 60 min), amplification products were detected through pH-dependent colour changes in the XO dye. The RT-LAMP-XO assay exhibited high specificity for FCoV, with no cross-reactivity against other common feline viral pathogens. While the detection limit (1.7 × 10¹ copies/µL) was an order of magnitude higher than that of qPCR, the method offered advantages in simplicity and speed compared to existing diagnostic approaches. Although less sensitive than qPCR, the RT-LAMP-XO assay may serve as a rapid screening tool when used in combination with additional primer sets. These findings demonstrate the potential utility of XO-based RT-LAMP as a simple, visual detection method for FCoV infection. Full article

To further enhance the safety and energy efficiency of the Fe₃O₄ preparation experiment, we proposed a strategy for synthesizing monodisperse Fe₃O₄ microspheres through a one-step solvothermal process. In this environmentally friendly synthesis method, stable FeCl₃∙6H₂O was utilized as the sole raw material, while ethylene glycol, characterized by its high boiling point and favorable safety profile, served as the solvent. Additionally, inexpensive and readily available urea was selected to function either as a mineralizer or surfactant. Through this one-step solvothermal reaction, the target product of Fe₃O₄ could be obtained without subsequent calcination under reducing or inert atmospheres, thereby enhancing experimental safety and promoting energy conservation. By controlling the amount of urea added, it became feasible to produce monodisperse magnetic Fe₃O₄ microspheres characterized by complete crystallinity and high yield. Utilizing the as-synthesized Fe₃O₄ as a catalyst, we investigated its photocatalytic activity against xylenol orange organic dyes along with its regeneration characteristics. When 40 mmol of urea was incorporated into the reaction mixture, the resulting Fe₃O₄ sample exhibited optimal photocatalytic performance; a 20 mg/L xylenol orange solution became colorless and transparent after just 1.5 h of UV light irradiation. Furthermore, during five consecutive regeneration cycles, its catalytic activity could be restored to its initial level. Importantly, Fe₃O₄ demonstrated excellent magnetic sensitivity properties that facilitated rapid targeted separation under an external magnetic field, providing convenience for recovery and collection purposes. Full article

Zirconium and hafnium have opposite nuclear properties and are used very differently in the nuclear industry. However, hafnium is a common metal impurity in zirconium, and the chemical properties of the two are very similar except for nuclear properties, and it is difficult to separate and detect them. At present, the detection of hafnium content in zirconium is usually achieved by using an inductively coupled plasma (ICP) spectrometer, but ICP equipment is expensive, and the detection cost is high. Therefore, it is necessary to develop a simple and low-cost method for the determination of hafnium content in zirconium. Based on this, this paper takes the spectrophotometric method as a starting point. Through a series of experiments on the influence of pH and concentrations of the color-developing agent xylenol orange sodium salt on the absorbance of zirconium and hafnium ions, the appropriate variables are selected to detect the content of hafnium in zirconium. Finally, according to the measured absorbance and total ion concentration, by comparing the working curve of zirconium and hafnium ions, the content of hafnium in zirconium is calculated based on the lever principle. Full article

In this work, a microfluidic paper-based analytical device (µPAD) for simultaneous detection of Fe, Zn, and Mn ions using immobilized chromogenic reagents Ferene S, xylenol orange, and 1-(2-pyridylazo)-2-naphthol, respectively, is presented. As the effective recognition of analytes via respective chromogens takes place under extremely different pH conditions, experiments reported in this publication are focused on optimization of the µPAD architecture allowing for the elimination of potential cross effects. The paper-based microfluidic device was fabricated using low-cost and well-reproducible wax-printing technology. For optical detection of color changes, an ordinary office scanner and self-made RGB-data processing program were applied. Optimized and stable over time, µPADs allow fast, selective, and reproducible multianalyte determinations at submillimolar levels of respective heavy metal ions, which was confirmed by results of the analysis of solutions mimicking real samples of wastewater. The presented concept of simultaneous determination of different analytes that required extremely different conditions for detection can be useful for the development of other multianalyte microfluidic paper-based devices in the µPAD format. Full article

Monoamine oxidases (MAOs), mitochondrial enzymes that constantly produce hydrogen peroxide (H₂O₂) as a byproduct of their activity, have been recently acknowledged as contributors to oxidative stress in cardiometabolic pathologies. The present study aimed to assess whether MAOs are mediators of valvular oxidative stress and interact in vitro with angiotensin 2 (ANG2) to mimic the activation of the renin–angiotensin system. To this aim, valvular tissue samples were harvested from 30 patients diagnosed with severe primary mitral regurgitation and indication for surgical repair. Their reactive oxygen species (ROS) levels were assessed by means of a ferrous oxidation xylenol orange (FOX) assay, while MAO expression was assessed by immune fluorescence (protein) and qRT-PCR (mRNA). The experiments were performed using native valvular tissue acutely incubated or not with angiotensin 2 (ANG2), MAO inhibitors (MAOI) and the angiotensin receptor blocker, irbesartan (Irb). Correlations between oxidative stress and echocardiographic parameters were also analyzed. Ex vivo incubation with ANG2 increased MAO-A and -B expression and ROS generation. The level of valvular oxidative stress was negatively correlated with the left ventricular ejection fraction. MAOI and Irb reduced valvular H₂O_2. production. In conclusion, both MAO isoforms are expressed in pathological human mitral valves and contribute to local oxidative stress and ventricular functional impairment and can be modulated by the local renin–angiotensin system_. Full article

Nanotechnology has provided considerable advancements in an array of disciplines. Recently, it has been shown that ferumoxytol, a magnetite (Fe₃O₄) nanoparticle, can be oxidized by ionizing radiation. Ferumoxytol nanoparticles have high stability, and thus can be hypothesized that they have dosimetric potential. In this study, it has been observed that xylenol orange, a colorimetric detector of Fe³⁺ used for conventional Fricke dosimetry, was not able to detect radiolytic changes in ferumoxtyol. Electron paramagnetic resonance (EPR) spectroscopy was more readily able to evaluate the oxidation of ferumoxytol. EPR spectroscopy revealed that oxidation of 500 nM ferumoxytol in H₂O was linear up to 20 Gy. This concentration, however, was unable to estimate the delivered dose from a Small Animal Radiation Research Platform system, as a 6 Gy dose was estimated to be 1.37 Gy, which represents a 79.2% underestimation of the dose delivered. Thus, while the high stability of Fe₃O₄ nanoparticles is attractive for use in pre-clinical radiation dosimetry, further radiochemical evaluation may be required before considering them for this application. Full article

Increasing evidence suggests that the gut microbiota, through the “microbiota–gut–brain axis”, can regulate anxiety, mood, and cognitive abilities such as memory and learning processes. Consistently with this, treatments altering the gut microbiota, such as antibiotics and probiotics, may influence brain function and impact behavior. The mechanisms that underlie the interplay between the intestinal microbiota and the brain have been intensively studied. We aimed to investigate the effects of two probiotic lactobacilli strains, Lacticaseibacillus rhamnosus 12L and Lactiplantibacillus plantarum 8PA3, on behavioral disorders in mice induced by a two-week parenteral treatment with broad-spectrum antibiotics. On completion of the treatment, the mice were subjected to behavioral tests, including the open field test (OFT), novel object recognition test (ORT), and T-maze test. Antibiotic-treated mice demonstrated anxiety-related behavior, decreased cognition, and retarded exploratory activity that were ameliorated by the administration of probiotics. As was determined by high-performance liquid chromatography (HPLC), both tested strains produced serotonin and its metabolite 5-hydroxyindoleacetic acid (5-HIAA), as well as dopamine, which was further metabolized into norepinephrine by L. plantarum 8PA3 and epinephrine by L. rhamnosus 12L. Moreover, these lactobacilli were found to harbor catecholamines and 3,4-dihydroxyphenylacetic acid (DOPAC) in their biomass when grown on MRS broth. Additionally, L. plantarum 8PA3 and L. rhamnosus 12L were able to impact oxidative stress via H₂O₂ production and antioxidant activity, as determined in this study by the ferrous oxidation–xylenol orange (FOX) assay and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay, respectively. The results obtained in this study support the role of probiotics as a promising therapeutic for neurological disorders. However, more investigations are required to confirm the clinical significance of this finding. Full article

Background and Objectives: This cross-sectional study conducted at the Timișoara Institute of Cardiovascular Diseases, Romania, and the Centre for Translational Research and Systems Medicine from “Victor Babeș” University of Medicine and Pharmacy of Timișoara, Romania, investigated the relationship between indexed epicardial adipose tissue thickness (EATTi) and oxidative stress in epicardial adipose tissue (EAT) adipocytes in the context of coronary artery disease (CAD) among open-heart surgery patients. The objective was to elucidate the contribution of EATTi as an additional marker for complexity prediction in patients with CAD, potentially influencing clinical decision-making in surgical settings. Materials and Methods: The study included 25 patients undergoing cardiac surgery, with a mean age of 65.16 years and a body mass index of 27.61 kg/m². Oxidative stress in EAT was assessed using the ferrous iron xylenol orange oxidation spectrophotometric assay. The patients were divided into three groups: those with valvular heart disease without CAD, patients with CAD without diabetes mellitus (DM), and patients with both CAD and DM. The CAD complexity was evaluated using the SYNTAX score. Results: The EATTi showed statistically significant elevations in the patients with both CAD and DM (mean 5.27 ± 0.67 mm/m²) compared to the CAD without DM group (mean 3.78 ± 1.05 mm/m², p = 0.024) and the valvular disease without CAD group (mean 2.67 ± 0.83 mm/m², p = 0.001). Patients with SYNTAX scores over 32 had significantly higher EATTi (5.27 ± 0.66 mm/m²) compared to those with lower scores. An EATTi greater than 4.15 mm/m² predicted more complex CAD (SYNTAX score >22) with 80% sensitivity and 86% specificity. The intra- and interobserver reproducibility for the EATTi measurement were excellent (intra-class correlation coefficient 0.911, inter-class correlation coefficient 0.895). Conclusions: EATTi is significantly associated with CAD complexity in patients undergoing open-heart surgery. It serves as a reliable indicator of more intricate CAD forms, as reflected by higher SYNTAX scores. These findings highlight the clinical relevance of EATTi in pre-operative assessment, suggesting its potential utility as a prognostic marker in cardiac surgical patients. Full article

The fast adsorption kinetics of zeolitic imidazolate frameworks (ZIFs) enable a wide range of sorption applications. The most commonly used framework, ZIF-8, is relatively non-polar. Increasing the polarity of ZIF-8 through the encapsulation of different polar species shows promise for enhancing the sorption performance for pure CO₂. Recently, the outlook has re-focused on gas mixtures, mostly in the context of post-combustion CO₂ capture from wet flue gasses. While water is known to sometimes have a synergistic effect on CO₂ sorption, we still face the potential problem of preferential water vapor adsorption. Herein, we report the preparation of three ZIF-8/organic dye (OD) composites using Congo red, Xylenol orange, and Bromothymol blue, and their impact on the sorption properties for CO₂, water, and a model wet CO₂ system at 50% RH. The results show that the preparation of OD composites can be a promising way to optimize adsorbents for single gasses, but further work is needed to find superior ZIF@OD for the selective sorption of CO₂ from wet gas mixtures. Full article

Hydrogen peroxide is an important intra- and inter-cellular messenger. It has been reported that beverages such as tea and coffee generate H₂O₂. The aim of this study was to examine whether H₂O₂ is formed in infusions of medicinal herbs and to explain the mechanism of its formation. Infusions of sixteen herbs were studied and the presence of H₂O₂ was found in all cases. The highest concentrations of H₂O₂, exceeding 50 µM, were found in the infusions of leaves of Betula and Polygonum, as well as of the inflorescence of Tilia. Considerable amounts of diverse phenolic compounds were detected in the infusions. Two successive one-electron oxidations of phenolics are the main source of H₂O₂ in these infusions; as expected, the generation of semiquinone and superoxide radicals was confirmed. The infusions of medicinal herbs were also able to scavenge H₂O₂. The herbal infusions were cytotoxic to human ovary cancer SKOV-3 and PEO1 cells; this cytotoxicity was compromised by catalase added to the growth medium, demonstrating the contribution of H₂O₂ to the cytotoxic action of herbal extracts. Full article

Various methodologies, sensitivities, and types of interference affect the quantification of plant hydrogen peroxide (H₂O₂) concentration. Modified ferrous oxidation xylenol orange (eFOX) assay and titanium sulfate (Ti(SO₄)₂ assay are relatively accessible methods. However, their correlation is unknown, for example whether we can get the same results for different species in different environments. Leaf samples of Ambrosia trifida, Solidago altissima, Artemisia princeps, and Sicyos angulatus were collected from a riparian vegetation zone on sunny days. The H₂O₂ concentration in the plant leaves was evaluated in two groups. Nonfrozen leaf samples were prepared for analysis soon after arriving at the laboratory, and frozen leaf samples were stored at −80 °C for 25 days and prepared afterwards. The eFOX assay can measure even lower fluctuations in H₂O₂ concentration than the Ti(SO₄)₂ assay. A substantial correlation was observed between nonfrozen and frozen samples in the eFOX (r = 0.879, p < 0.001) and Ti(SO₄)₂ assays (r = 0.837, p < 0.001). Sample weight did not affect H₂O₂ quantification. Each species showed a substantial correlation between the eFOX and Ti(SO₄)₂ assays in nonfrozen conditions (Ambrosia trifida (r = 0.767, p < 0.001), Solidago altissima (r = 0.583, p < 0.001), Artemisia princeps (r = 0.672, p < 0.001), and Sicyos angulatus (r = 0.828, p < 0.001)). Therefore, both methods can be utilized easily and rapidly to quantify oxidative stress using H₂O₂. Full article

The field of bone tissue engineering has shown a great variety of bone graft substitute materials under development to date, with the aim to reconstruct new bone tissue while maintaining characteristics close to the native bone. Currently, insufficient scaffold degradation remains the critical limitation for the success of tailoring the bone formation turnover rate. This study examines novel scaffold formulations to improve the degradation rate in vivo, utilising chitosan (CS), hydroxyapatite (HAp) and fluorapatite (FAp) at different ratios. Previously, the P28 peptide was reported to present similar, if not better performance in new bone production to its native protein, bone morphogenetic protein-2 (BMP-2), in promoting osteogenesis in vivo. Therefore, various P28 concentrations were incorporated into the CS/HAp/FAp scaffolds for implantation in vivo. H&E staining shows minimal scaffold traces in most of the defects induced after eight weeks, showing the enhanced biodegradability of the scaffolds in vivo. The HE stain highlighted the thickened periosteum indicating a new bone formation in the scaffolds, where CS/HAp/FAp/P28 75 µg and CS/HAp/FAp/P28 150 µg showed the cortical and trabecular thickening. CS/HAp/FAp 1:1 P28 150 µg scaffolds showed a higher intensity of calcein green label with the absence of xylenol orange label, which indicates that mineralisation and remodelling was not ongoing four days prior to sacrifice. Conversely, double labelling was observed in the CS/HAp/FAp 1:1 P28 25 µg and CS/HAp/FAp/P28 75 µg, which indicates continued mineralisation at days ten and four prior to sacrifice. Based on the HE and fluorochrome label, CS/HAp/FAp 1:1 with P28 peptides presented a consistent positive osteoinduction following the implantation in the femoral condyle defects. These results show the ability of this tailored formulation to improve the scaffold degradation for bone regeneration and present a cost-effective alternative to BMP-2. Full article

The purpose of this trial was to evaluate serum levels of oxidative stress biomarkers and biochemical analytes in crossbred lambs during the rearing phase in an integrated crop-livestock system (ICLS) to control gastrointestinal parasites. The experiment used 36 crossbred lambs (cross: Ile de France × White Dorper × Texel) divided into two groups. The WCS group was supplemented with whole cottonseed (WCS), and controls had no supplementation. Body weight, blood collection, and fecal analysis of nematode eggs and Eimeria oocysts counting per gram of feces were performed for each animal within 84 days of experiment. The following serum analytes were determined: total protein, albumin, globulin, cholesterol, haptoglobin, and 10 oxidative stress biomarkers: cupric reducing antioxidant capacity, ferric reducing ability of plasma, trolox equivalent antioxidant capacity, thiol, uric acid, paraoxonase-1, total oxidant status, ferric-xylenol orange, advanced oxidation protein products, and reactive oxygen metabolites derived compounds. The inclusion of WCS suggested the benefit in controlling infection as well as inducing an increase in antioxidants and a decrease in oxidants in lambs naturally infected by gastrointestinal parasites. The combination of WCS and ICLS could be a useful tool in controlling gastrointestinal parasite infection without affecting the production performance. Full article

ROS homeostasis is crucial to maintain radical levels in a dynamic equilibrium within physiological ranges. Therefore, ROS quantification in seeds with different germination performance may represent a useful tool to predict the efficiency of common methods to enhance seed vigor, such as priming treatments, which are still largely empirical. In the present study, ROS levels were investigated in an experimental system composed of hydroprimed and heat-shocked seeds, thus comparing materials with improved or damaged germination potential. A preliminary phenotypic analysis of germination parameters and seedling growth allowed the selection of the best-per-forming priming protocols for species like soybean, tomato, and wheat, having relevant agroeconomic value. ROS levels were quantified by using two noninvasive assays, namely dichloro-dihydro-fluorescein diacetate (DCFH-DA) and ferrous oxidation-xylenol orange (FOX-1). qRT-PCR was used to assess the expression of genes encoding enzymes involved in ROS production (respiratory burst oxidase homolog family, RBOH) and scavenging (catalase, superoxide dismutase, and peroxidases). The correlation analyses between ROS levels and gene expression data suggest a possible use of these indicators as noninvasive approaches to evaluate seed quality. These findings are relevant given the centrality of seed quality for crop production and the potential of seed priming in sustainable agricultural practices. Full article