Archivio Istituzionale della Ricerca- Università del Salento
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Multifractal analysis of braided channel networks using structure functions and fixed-mass measures
No full textThis study presents a multifractal analysis of braided channel networks using a coupled approach that integrates structure functions and fixed-mass measures. The investigation focuses on three braided river systems (namely, Allaro River, Brahmaputra River and Rakaia River), examining the behavior of the number of wet channels measured along the longitudinal spatial development of the river reach. The number of wet channels is shown to be an intermittent 1D signal, whose physical scaling is governed by scaling laws that can be naturally described by multifractal measures. By employing this combined approach, we were able to identify the maximum order of the moments of the measures that characterizes the multifractal spectrum and multiscaling properties of braided channel systems. The methodology for estimating the multifractal spectra is based on a modified Legendre ransform relation for singularity strengths, allowing for a quantitative comparison between the multifractal spectra derived from structure functions and those obtained using the fixed-mass method
Silver Nanoparticle–Silk Protein Nanocomposites: A Synergistic Biomimetic Approach for Advanced Antimicrobial Applications
No full textThe escalating global crisis of antimicrobial resistance demands innovative therapeutic strategies that transcend conventional approaches. This comprehensive review examines the groundbreaking synergistic integration of silver nanoparticles (AgNPs) with silk proteins (fibroin and sericin from Bombyx mori) to create advanced nanocomposite materials for biomedical applications. While extensive literature exists for AgNPs and silk proteins individually, a limited number of studies have explored their synergistic combination. This review consolidates this fragmented knowledge to establish the foundational framework for an emerging field. The unique properties of silk proteins as natural reducing, stabilizing, and capping agents enable environmentally friendly AgNPs synthesis while creating intelligent therapeutic platforms with emergent properties. These hybrid materials demonstrate superior performance in terms of antimicrobial efficacy, biocompatibility, and accelerated wound healing compared to the individual components. The nanocomposites exhibit broad-spectrum activity against multidrug-resistant pathogens while maintaining exceptional biocompatibility and promoting tissue regeneration. This integration represents a promising evolution toward biomimetic therapeutic platforms that work in harmony with biological systems, offering sustainable solutions to contemporary healthcare challenges
Detecting causal relations among indicators with the CTA test: simulations and applications
Get PDFIn the context of using structural equation modelling to develop economic and social indicators, a debate regarding the choice of measurement modes for theoretical constructs is becoming a very important issue, with conceptual and practical implications. The nature of each construct, which can be defined as reflective or formative, is mainly based on theoretical considerations, but confirmatory tetrad analysis (CTA) can support decisions about the model specification. One flexible approach to carrying out CTA involves multiple hypothesis testing, which also provides relevant information on empirical data to guide the construction of composite indicators. This prompts a deeper investigation of the effects of correction methods on decisions derived from tests, with special attention to error control and statistical power. In this study, we explore the properties of six procedures, in particular the well-known Bonferroni and Benjamini–Hochberg corrections, using various simulation scenarios and real applications. We find that, with respect to the Benjamini–Hochberg, the Bonferroni correction is too conservative and has lower power, especially with small sample sizes and many manifest variables
Morpho-Functional Responsiveness of Caco-2 Enterocyte-like Monolayers to Insulin in a Pro-Inflammatory Environment
No full textIn exerting its actions on the utilization and storage of nutrients, the hormonal effects of insulin (INS) on target cells include important changes in terms of cell morphology involving cytoskeletal actin. Sensitivity to INS affects intestinal epithelial cells, which express receptors through which tight junctions and barrier permeability are also modulated. Nevertheless, the impact of INS on physiological rather than pathophysiological processes along gastrointestinal epithelia is not fully established. Here, we investigate INS effects on differentiated Caco-2 monolayers challenged by inflammatory stimuli, i.e., interleukin 1 beta (IL-1β) and interferon gamma (IFN-γ), aiming to identify morpho-functional variations potentially associated with INS-dependent responses in intestinal epithelia differentially driven by different inflammation mediators. By observing the actin cytoskeleton, we characterized the impact of INS on actin structures’ organization, both in the absence and presence of pro-inflammatory treatments. Coherently, we observed altered expression of proteins interrelated to cytoskeletal dynamics (FAK, ITGB1), particularly evident in the synergistic action of IFN-γ and INS, also confirmed by the impact on INS-mediated regulation of the MAPK signalling pathway. Overall, the results describe a modular responsiveness of enterocyte-like monolayers to INS, depending on different inflammatory mediators, hinting at the interplay between INS signalling and morpho-functional remodelling in intestinal epithelial cells
A new branch of research for analysing archaeological context: application of Drone-based magnetometer
No full textPostcardiotomy extracorporeal membrane oxygenation in patients older than 70 years: Characteristics, outcomes, and variables associated with mortality
No full textObjectives: Age is the main determinant for mortality in patients requiring postcardiotomy extracorporeal membrane oxygenation (PC-ECMO), but strategies to reverse this trend are unknown. This study investigates PC-ECMO outcomes in older patients (≥70 years) compared with younger patients (<70 years). Methods: This retrospective study included patients who required PC-ECMO between 2000 and 2020. Variables independently associated with in-hospital mortality were identified using mixed Cox proportional hazards models. Results: The study included 2057 patients (mean age: 62.3 [first and third quartile: 19-94]; male patients: n = 1213 [59%]): 1376 (67%) were <70 years and 680 (33%) were ≥70 years old. Older patients had more preoperative comorbidities, whereas younger patients had lower cardiac function and more preoperative intubation and vasopressor use. In-hospital mortality was 56.3% (n = 775) and 68.8% (n = 468) in the <70 year and ≥70 year groups, respectively (P < .001). The 7-year postdischarge survival rate was greater for the younger patient group (P < .001). Variables associated with in-hospital mortality in older patients were previous stroke (hazard ratio [HR], 1.39; 95% confidence interval [CI], 1.05-1.84), preoperative right ventricular failure (HR, 1.45; 95% CI, 1-2.1), aortic surgery (HR 1.65; 95% CI, 1.2-2.2), and postoperative complications including bleeding (HR 1.24; 95% CI, 1.0-1.5), cardiac arrest (HR, 1.65; 95% CI, 1.3-2.1), and right ventricular failure (HR, 1.29; 95% CI, 1.0-1.6). Conclusions: PC-ECMO mortality is high in older patients. Preoperative factors including previous stroke and right ventricular failure and postoperative factors including bleeding, cardiac arrest, and right ventricular failure should be targeted to reduce in-hospital mortality after appropriate initial selection in older patients
Beauveria bassiana delivered through a cellulose-based hydrogel is effective against the red poultry mite, Dermanyssus gallinae
No full text: Though the entomopathogenic fungus Beauveria bassiana has shown to be efficacious for managing Dermanyssus gallinae infestations, its delivery as liquid formulation poses concerns related to environmental stability and efficacy. To overcome such concerns, here we proposed a hydrogel matrix based on hydroxyethyl-cellulose (HEC) for delivering B. bassiana to control D. gallinae. Nymph and adult mites were exposed to a hydrogel matrix or filter papers containing B. bassiana (107 conidia/mL), with and without a pre-incubation period of 4 days at 25 °C (treated groups). As control groups, mites were exposed to hydrogel matrix or filter papers with sterile distilled water. Results showed higher mortality of all stages of D. gallinae in treated groups compared to respective control groups. The LT50 and LT90 estimated on D. gallinae were lower in treated groups (LT50 ≤ 9.5 days for adults; and LT50 ≤ 10.7 days for nymphs; LT90 ≤ 14.9 for adults; LT90 ≤ 17.9 days for nymphs) than in control groups (LT5 0 ≥14.9 days for adults, LT50 > 19 days for nymphs; LT90 > 20 days for adults and nymphs). Pre-incubation significantly reduced LT50 and LT90 with respect to other treated groups. Overall, our study outlined that the conidial suspension of B. bassiana in hydrogel is efficacious against both nymphs and adults of D. gallinae. The pre-incubation of B. bassiana in the HEC enhanced its efficacy. Thus, delivering B. bassiana through HEC-based hydrogel matrix may represent an effective and sustainable solution for managing D. gallinae infestations in the poultry industry
Synthesis and annealing effects on microstructure and optical properties of wide-bandgap polycrystalline ferro-pseudobrookite FeTi2O5 sol-gel layers
Get PDFWide bandgap (WBG) and high thermal stability pseudobrookite compounds, Fe1+xTi2−xO5 (0 ≤ x ≤ 1), are promising materials for photocatalysis, high-temperature thermoelectric applications, green production of hydrogen by water splitting, fabrication of power electronics, and optoelectronic devices. Here, we report on WBG, polycrystalline, ferropseudobrookite, FeTi2O5, coatings, stable at high temperature, prepared by an optimized sol-gel route on fused silica and silicon substrates. The chemical composition, the amorphous-to-crystalline phase transformation, and the influence of the annealing temperature and atmosphere (air and argon) on the formation and evolution of the crystalline phases were investigated in detail by combining thermogravimetric and differential scanning calorimetry analysis with Fourier-transform infrared spectroscopy and X-ray diffraction. The experimental results clearly show that orthorhombic FeTi2O5 single phase develops in the interval 500–560 °C (crystalline domain size about 16 nm at 560 °C). The coatings remain in a single FeTi2O5 phase up to a temperature of about 590 °C. At higher temperatures, a rutile-TiO2 secondary phase is formed, both in an oxidizing and inert atmosphere, while the ferropseudobrookite phase remains unchanged. The results suggest that the secondary phase arises from the presence of superficial Ti-O- dangling bonds that at temperatures above 590 °C begin to arrange themselves to form polycrystalline rutile-TiO2 (crystalline domain size ≈8 nm at 620 °C). The results also show that the average energy required to break the Ti-O-Ti molecular bonds of the FeTi2O5 phase increases with temperature, improving its thermal stability. Optical absorption spectroscopy measurements carried out on coatings heated at 560 °C, yield an optical bandgap of about 2.25 eV, a refractive index of about 1.84 at 550 nm, and a weak UVC positive band, peaked at about 5.9 eV, on transmittance that disappears when the samples are annealed at 750 °C
