Search Results (13,449)

We have designed and built an improved system for combined Time-Domain Near-Infrared Spectroscopy (TD NIRS) and Diffuse Correlation Spectroscopy (DCS) measurements. The system features two independent channels, enabling TD NIRS and DCS acquisition at short and long source-detector distances to enhance depth sensitivity in layered tissues. Moreover, the device can operate at fast acquisition rates (up to 50 Hz) to monitor hemodynamic oscillations in biological tissues. An OEM (Original Equipment Manufacturer) TD NIRS device enables stable and robust acquisition of photon distribution of time-of-flight. For the DCS signals, the use of a time tagger and a software correlator allows us flexibility in post-processing. A user-friendly GUI controls TD NIRS data acquisition and online data analysis. We present results for the system characterization on calibrated tissue phantoms according to standardized protocols for performance assessment of TD NIRS and DCS devices. In-vivo measurements during rest and during vascular occlusions are also reported to validate the system in real settings. Full article

The pharmacokinetics of Δ⁹-tetrahydrocannabinol (Δ⁹-THC) has not been established in ruminants. Pharmacokinetic knowledge is important given feeding industrial hemp biomass has been shown to result in tissue residues post feeding in sheep. Due to a lack of testing and available data, a ‘maximum’ concentration of Δ⁹-THC has not been currently set for foods of animal origin. Consequently, this study was designed to gain a better understanding of how ruminants process Δ⁹-THC. Eight Merino ewes were administered with two per os (PO) doses of 88.5 mg Δ⁹-THC/kg bodyweight (BW) 12 h apart. Blood samples were collected periodically post dosing to determine the pharmacokinetics of Δ⁹-THC and subcutaneous fat biopsies were taken to investigate the deposition and elimination of Δ⁹-THC from sheep. An elimination half-life of 31.40 ± 13.87 h was identified, with residues persisting in the subcutaneous fat for 28 d in five of the eight sheep, before decreasing below the limit of detection in all sheep by 91 d. These results support the prolonged presence of Δ⁹-THC residues previously identified. Thus, imposing a practical withholding period for ruminants involved in the food chain may not be possible, with further research required to investigate how iHemp biomass may be safely fed to ruminants. Full article

This study applies UAV-based photogrammetry to map and examine the stratigraphy and archaeological artifact distribution in two localities within the Post research area in northwest Texas. A DJI Inspire 1 UAV equipped with a Zenmuse X5 camera captured nadir and oblique images. These were processed using Agisoft Metashape to generate 3D models. These models enabled the precise mapping of stratigraphic boundaries, revealing the distinctions between Triassic-age bedrock, Pleistocene-age alluvial deposits, and Holocene-age aeolian sediments. Field surveys from 2022 to 2024 documented over 5000 artifacts with sub-centimeter accuracy, including diagnostic projectile points and ceramics. This research highlights the advantages of UAV-derived 3D models in rapidly and accurately documenting stratigraphy and archaeological data. It demonstrates the value of UAV technology for visualizing landscape-scale processes and artifact contexts, offering a new approach to understanding the interactions between geomorphology and archaeology. The findings contribute to advancing UAV applications in both geomorphological and archaeological research. Full article

This paper presents an investigation into the use of pyrolysis to valorise solid waste in the form of post-consumer footwear uppers. A heterogenous leather and textile mixture is studied, produced by crushing some representative samples of post-consumer footwear uppers. The waste has a low ash content and a high net calorific value, which translates into the high gross calorific value of the material. In addition, it contains relatively little S and Cl, which is promising for its use in the process of pyrolysis. The effect of the pyrolysis temperature on the efficiency of carbonising leather and textile mixtures, their physico-chemical parameters, elemental composition, and structure, as well as the development of a specific surface, is investigated. The research results imply that as the pyrolysis temperature grows, the carbonisation efficiency declines. The produced materials consist primarily of C, O, N, and H, whose contents depend on the pyrolysis temperature. Moreover, all the carbonised materials display the presence of two G and D bands, which is typical for carbon materials. Based on the peak intensities of the bands, I_D/I_G coefficients are calculated to assess the organisation of the materials’ structures. As the pyrolysis temperature rises, the structural organisation declines, contributing to an increased material porosity and, thus, a greater specific surface of the carbonised materials. This study contributes data on the thermal management and pyrolysis of leather and textile waste into useful carbonised materials. Investigating the applicability of carbonised materials is projected as the next stage of research work. Full article

This article concerns the analysis and strengthening of children’s emotional self-regulation as a key process in the sustainable and comprehensive educational development of students from 6 to 8 years of age. The objective of the present study was to design a didactic proposal for technological mediation (WhatsApp) that contributes to emotional self-regulation and underpins the sustainable education of children in the context of the prevalence of COVID-19. The research design involved documentation, field, and propositional work. Regarding the documentation design, the content analysis technique of the Institutional Educational Project and the Coexistence Project of an official educational institution located in Bogotá, Colombia, were used. Regarding the field design, the survey technique was applied through a structured questionnaire for populations made up of second grade primary school students, parents, and teachers of the institution. Among the main results, it stands out that the prevalence of COVID-19 and its post-pandemic implications have generated greater use of available technologies, such as the WhatsApp application, evidencing a positive relationship between the level of emotional self-regulation of children and its use as a didactic mediation agent. These findings serve as input for the design of the interactive TICSR-WA proposal. Full article

Ovarian tissue cryopreservation has been widely investigated for preserving female fertility. In the present study, we aimed to compare the effects of three concentrations (1, 1.5, and 3 M) of dimethylsulfoxide (DMSO) on the vitrification of ovarian tissue. The ovarian cortex was divided into control and vitrified groups: (i) 1 M-DMSO, (ii) 1.5 M-DMSO, and (iii) 3 M-DMSO. Follicles from all fragments were analyzed for DMSO-induced deleterious effects, morphological and morphometric aspects, and concentration of reactive oxygen species. Additionally, the fragments were cultured to assess the integrity and return of follicular development post-vitrification. All DMSO concentrations resulted in a higher percentage of degenerated preantral follicles than before the cryopreservation process. After vitrification, the cryopreserved ovarian fragments showed similar percentages of intact follicles; however, the 3 M DMSO concentration differed from the control. Analyzing free radical production, we found that the 3 M DMSO concentration had higher levels of oxidative stress than the lower DMSO. After in vitro cultivation of the vitrified/warmed fragments, the 1 M DMSO concentration exhibited higher percentages of morphologically intact follicles than the other concentrations. Therefore, we suggest that bovine preantral follicles can be cryopreserved in situ with greater efficiency in 1 M DMSO. Full article

Research studies for cellulose recovery from lignocellulosic materials are essential in order to propose sustainable alternatives to harness residual biomasses, solving problems caused by their abundance and inadequate use. In this study, olive-tree pruning biomass has been subjected to different pretreatments with different organosolvents (acetone, ethanol, and $\gamma$-valerolactone) with microwave radiation assistance. The effect of operating parameters has been studied, considering specific ranges of variables values according to each experimental design but, in any case, located in the ranges of 33–67% (chemical compound concentration), 130–170 °C (temperature), 5–30 min (reaction time), and 1/20–1/5 (solid/liquid ratio, s/L). Based on the R² and R²_adj values (mostly above 0.97), the experimental data were adequately adjusted to four selected response variables: post-solids cellulose and lignin content apart from removal percentages of both structural components. The optimization process resulted in post-treatment solids with meaningful cellulose yields (higher than 84.7%) and reduced lignin content (lower than 4.2%). The best results were obtained using 66.5% acetone (155 °C, 8.4 min and s/L = 1/19), involving greater material deconstruction, a high percentage of delignification (96.7%), not very significant cellulose loss (29.4%), and a post-treatment solid consisting almost exclusively of cellulose (≈99%). Full article

Forest fires represent a significant intersection between nature and society, often leading to the loss of natural resources, soil nutrients, and economic opportunities, as well as causing desertification and the displacement of communities. Therefore, the objective of this work is to analyze the multitemporal conditions of a sixth-generation forest fire through the use and implementation of tools such as remote sensing, photointerpretation with geographic information systems (GISs), thematic information on land use, and the use of spatial indices such as the Normalized Difference Vegetation Index (NDVI), the Normalized Burned Ratio (NBR), and its difference (dNBR) with satellite images from Sentinel-2. To improve our understanding of the dynamics and changes that occurred due to the devastating forest fire in Los Guájares, Granada, Spain, in September 2022, which affected 5194 hectares and had a perimeter of 150 km, we found that the main land use in the study area was forest, followed by agricultural areas which decreased from 1956 to 2003. We also observed the severity of burning, shown with the dNBR, reflecting moderate–low and moderate–high levels of severity. Health and part of the post-fire recovery process, as indicated by the NDVI, were also observed. This study provides valuable information on the spatial and temporal dimensions of forest fires, which will favor informed decision making and the development of effective prevention strategies. Full article

The Alattu–Päkylä gold occurrence is located in the Northern Lake Ladoga area, in the Raaha-Ladoga suprasubduction zone, at the Karelian Craton (AR)—Svecofennian foldbelt (PR₁) boundary. Its gold ore mineral associations are of two types of mineralization: (1) copper–molybdenum–porphyry with arsenopyrite and gold (intrusion-related) and (2) gold–arsenopyrite–sulfide in shear zones. Optical and scanning electron microscopy, X-ray fluorescence spectrometry, inductively coupled plasma mass spectrometry (ICP-MS), instrumental neutron activation analysis (INAA) and fire analysis with AAS finishing were used to study them. Type 1 was provoked by shallow-depth tonalite intrusion (~1.89 Ga) and type 2 by two stages of Svecofennian metamorphism (1.89–1.86 and 1.83–1.79 Ga) with the possible influence of the impactogenesis of the Janisjärvi astrobleme (age ~1 Ga). Intrusive and host rocks were subjected to shearing accompanied by the formation of ore-bearing metasomatic rocks of the propylite-beresite series (depending on substrate) and quartz–sericite, quartz and sericite–tourmaline veins and streaks. Ore mineralization is present as several consecutive mineral associations: pyritic–molybdenite with arsenopyrite and gold; gold–arsenopyrite; quartz–arsenopyrite with antimony sulfosalts of lead; gold–polysulfide with tetrahedrite –argentotetrahedrite series minerals and gold–antimony with Pb–Sb–S system minerals and native antimony. Arsenopyrite contains invisible (up to 234 ppm) and visible gold. Metamorphosed domains in arsenopyrite and rims with visible gold around it are usually enriched in As, indicating higher (up to >500 °C) temperatures of formations than original arsenopyrite with invisible gold (<500 °C). A paragenetic sequence associated with the deposition of invisible and visible gold established at the Alattu–Päkylä ore occurrence: pyrrhotite + unaltered arsenopyrite (with invisible gold) → altered arsenopyrite (As-enriched) + pyrite ± pyrrhotite + visible gold. Gold, associated with gudmundite, sphalerite and native antimony, seems to be due to cainotypic rhyodacitic porphyry cutting tonalite intrusion or with a retrograde stage in post-Svecofennian metamorphism. The isotopic composition of Pb and ²³⁸U/²⁰⁴Pb (9.4–9.75) for the feldspar of the tonalite intrusion and the pyrite of gold mineralization, εNd (−4 up to −5) for tonalites and ẟ³⁴S values of −2.10–+4.99 for arsenopyrite, indicate the formation of gold occurrence provoked by Svecofennian magmatic and tectono-thermal processes with the involvement of matter from a mantle-lower crustal reservoir into magma formation and mineralization. Full article

Polyethylene terephthalate (PET) is widely used in bottle production by stretch blow molding processes (SBM processes) due to its cost-effectiveness and low environmental impact. The presented literature review focuses on microcavitation and solid-state post-condensation effects that occur during the deformation of PET in the SBM process. The literature review describes cavitation and microcavitation effects in PET material and solid-state post-condensation of PET on the basis of a three-phase model of the PET microstructure. A three-phase model of PET microstructure (representing the amorphous phase in two ways, depending on the ratio of the trans-to-gauche conformation of the PET macromolecule and the amount of free volume) with a nucleation process, a crystallization process, and the use of positron annihilation lifetime spectroscopy (PALS) to analyze PET microstructure are discussed in detail. The conceptual model developed based on the literature combines solid-state post-condensation with microcavitation via the diffusion of the post-condensation product. This review identifies the shortcomings of the developed conceptual model and presents them with five hypotheses, which will be the basis for further research. Full article

microRNAs (miRNAs) influence many biological processes at the post-transcriptional level. However, the molecular characterization of miRNAs in the Myzus persicae response to Brassica yellows virus (BrYV) stress remains unclear. In this study, we present the results of miRNA profiling in Myzus persicae under two different treatments: treatment one (raised on turnip plants), and treatment two (raised on Arabidopsis thaliana). A total of 72 known and 113 novel mature miRNAs were identified in both non-viruliferous and viruliferous aphids, under treatment one. In treatment two, 72 known and 112 novel mature miRNAs were identified in BrYV-free aphids; meanwhile, 71 known and 115 novel miRNAs were identified in BrYV-carrying aphids. Moreover, eight upregulated and four downregulated miRNAs were identified in viruliferous aphids under treatment two, whereas only two miRNAs were differentially expressed under treatment one. These results indicated the relative BrYV level could influence miRNA expression in aphids. KEGG enrichment analysis showed the predicted genes targeted by differentially expressed miRNAs were primarily involved in Peroxisome, neuroactive ligand–receptor interaction, and metabolism of xenobiotics by cytochrome P450 pathways. Taken together, these findings reveal the effect of BrYV on miRNAs in Myzus persicae and provide key clues for further studies on the molecular mechanisms of BrYV transmission via aphids. Full article

The demand for advanced Al-based alloys with tailored structural and magnetic properties has intensified for applications requiring a high thermal stability and performance under challenging conditions. This study investigated the phase evolution, magnetic properties, thermal stability, and microstructural changes in the Al-based alloys Al₈₂Fe₁₆Nb₂ and Al₈₂Fe₁₄Nb₂Mn₂, synthesized via mechanical alloying (MA), using stearic acid as a process control agent. The X-ray diffraction results indicated that Al₈₂Fe₁₆Nb₂ achieved a β-phase solid solution with 13–14 nm crystallite sizes after 5 h of milling, reaching an amorphous state after 10 h. In contrast, Al₈₂Fe₁₄Nb₂Mn₂ formed a partially amorphous structure within 10 h, with enhanced stability with additional milling. Magnetic measurements indicated that both alloys possessed soft magnetic behavior under shorter milling times (1–5 h) and transitioned to hard magnetic behavior as amorphization progressed. This phenomenon was associated with a decrease in saturation magnetization (M_s) and an increase in coercivity (H_c) due to structural disorder and residual stresses. Thermal stability analyses on 10 h milled samples conducted via differential scanning calorimetry showed exothermic peaks between 300 and 800 °C, corresponding to phase transformations upon heating. Post-annealing analyses at 550 °C demonstrated the presence of phases including Al, β-phase solid solutions, Al₁₃Fe₄, and residual amorphous regions. At 600 °C, the Al₃Nb phase emerged as the β-phase, and the amorphous content decreased, while annealing at 700 °C fully decomposed the amorphous phases into stable crystalline forms. Microstructural analyses demonstrated a consistent reduction in and homogenization of particle sizes, with particles decreasing to 1–3 μm in diameter after 10 h. Altogether, these findings highlight MA’s effectiveness in tuning the microstructure and magnetic properties of Al–Fe–Nb (Mn) alloys, making these materials suitable for applications requiring a high thermal stability and tailored magnetic responses. Full article

This study aims to explore allocation strategies for idle emergency supplies in a “demander–platform–supplier” supply chain system along with government regulation during the post-disaster recovery period. Allocation of emergency supplies is a complex task that encompasses resource allocation before and after disasters. It is essential to reduce losses in disaster-stricken areas and support development during post-disaster recovery. However, there is often an excessive supply of emergency materials and a mismatch between supply and demand sides in downstream supply chains, which may lead to severe waste and difficulties in recovering surplus materials. This paper takes idle emergency resource sharing level and corporate social responsibility goodwill as endogenous variables. The allocation approaches are dynamically evaluated by incorporating random elements that influence the endogenous variables. Three stochastic differential games are introduced to examine the interactions between the players. The centralized decision-making satisfies the consistency of overall and individual rationalities at any time in the emergency material allocation process, promoting the optimal sharing levels of emergency materials and overall profits. The decentralized decision-making with cost-sharing contracts achieves local optima and increases the dual marginal effect of the emergency industry chain. This paper incorporates the sharing economy into emergency management, showing how technology-driven sharing platforms can optimize resource utilization. The results suggest introducing cost-sharing contracts between demanders and suppliers can enhance collaboration and effort, leading to better resource allocation and increased efficiency. It contributes to sustainability by promoting efficient resource utilization through idle emergency resource sharing. By optimizing allocation strategies and enhancing corporate social responsibility, the study fosters the long-term viability and resilience of the supply chain system in post-disaster management. Full article

Silicone rubbers based on poly(dimethylsiloxane) (PDMS) are crosslinked elastomers commonly used in various branches of industry, especially as packing materials in elements for high-temperature service. In addition to high temperatures, mechanical loading may influence their structure during their work, and, as a consequence, their thermal properties may change. This study’s findings on the degradation mechanism under aging conditions are not just necessary, but also crucial for their satisfactory application. The aim of the study was a detailed and comprehensive evaluation of the aging processes of commercial ELASTOSIL^® LR 3842/50 A/B, considering structural changes based on thermal analysis accompanied by mass spectroscopy, X-ray analysis, and infrared spectroscopy. The aging process was carried out at 125 °C and 175 °C, without and with 11 kg of loading. The obtained results showed that the aging of PDMS increased their thermal stability. It was the most visible for PDMS aging at 175 °C under load. It was attributed to secondary crosslinking and the post-curing process. Observed changes in polymer structure did not indicate its degradation. This is a significant finding, especially considering that a temperature of 175 °C is close to the critical temperature given by the producer (180 °C), above which the use of stabilizing agents is recommended. Full article

Left atrial appendage occlusion (LAAO) has emerged as a highly effective alternative to oral anticoagulation for stroke prevention in patients with non-valvular atrial fibrillation. Precise pre-procedural planning and meticulous post-procedural follow-up are essential for achieving successful LAAO outcomes. This review explores the latest advancements in three-dimensional (3D) transoesophageal echocardiography (TOE) and computed tomography (CT) imaging modalities, which have considerably improved the planning, intra-procedural guidance, and follow-up processes for LAAO interventions. Innovations in 3D TOE and CT imaging have transformed the approach to LAAO by providing a more detailed and accurate assessment of the left atrial appendage, enabling clinicians to acquire comprehensive anatomical and morphological information, crucial for optimising device selection and positioning, thus reducing the risk of complications and enhancing the overall safety and efficacy of the procedure. Post-procedurally, CT and TOE imaging are invaluable in the monitoring of patients, ensuring that the device is correctly positioned and functioning as intended. Early detection of any complications (e.g., device-related thrombus and peri-device leaks) can help to risk-stratify patient at increased risk of stroke and initiate timely interventions, thereby improving long-term outcomes for patients. Full article