Archivio Istituzionale della Ricerca- Università del Salento
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Analysis of flexural behaviour of steel reinforced cement-less concrete beam
Get PDFLimited information exists in the scientific literature on the structural performance of reinforced elements using cement-less concrete mixes. To address this gap, an experimental investigation was conducted to evaluate the structural behavior of reinforced geopolymer concrete (GPC) beam elements. This study specifically examines the bending performance of GPC beams compared to Ordinary Portland Cement Concrete (OPCC) beams, focusing on failure loads, deflections, strains, and crack patterns. Three beams were tested under four-point bending: two with GPC mixes and one with OPCC as a reference. The maximum loads achieved by the GPC beams were 14 % and 9 % higher than the OPCC reference beam, while the OPCC beam failure load was 9 % above its expected maximum. Maximum strains of 4.3 ‰ and 3.7 ‰ were recorded for the GPC beams, closely aligning with the 3.5 ‰ design value for OPCC. Load-displacement analysis revealed negligible differences in the elastic behavior for all beams, as well as for ductility and deformation at service load. On the other hand, Cracking moments for GPC beams were observed to be up to 34 % lower than OPCC, likely due to differences in tensile strength and microstructural composition. Overall, the experimental results demonstrated that GPC beams can be designed using OPCC structural provisions with comparable accuracy, as evidenced by the alignment of experimental and theoretical moment-curvature curves. Finally, an experimental-analytical comparison according to the existing standards suggestions was carried out
Galleria mellonella (Greater Wax Moth) as a Reliable Animal Model to Study the Efficacy of Nanomaterials in Fighting Pathogens
Get PDFThe spread of multidrug-resistant microbes has made it necessary and urgent to develop new strategies to deal with the infections they cause. Some of these are based on nanotechnology, which has revolutionized many fields in medicine. Evaluating the safety and efficacy of these new antimicrobial strategies requires testing in animal models before being tested in clinical trials. In this context, Galleria mellonella could represent a valid alternative to traditional mammalian and non-mammalian animal models, due to its low cost, ease of handling, and valuable biological properties to investigate host–pathogen interactions. The purpose of this review is to provide an updated overview of the literature concerning the use of G. mellonella larvae as an animal model to evaluate safety and efficacy of nanoparticles and nanomaterials, particularly, of those that are used or are under investigation to combat microbial pathogens
Regionalization Methods for Compound Extremes Based on the Wasserstein Distance
No full textA clustering algorithm is presented in order to group time series of maxima for pair of random variables recorded at different stations. The method is based on two kinds of dissimilarity measure. The first one involves the distance of the marginal distributions; the second one involves the distance between the respective copulas. In both cases, a Wasserstein metric is used. For the estimation, we rely on tools for extreme-value distributions and copulas
A lezione da Pasolini (ieri e oggi)
No full textQuesto studio si concentra sull'attività scolastica di Pasolini attraverso gli esempi di alcune proposte didattiche relative al periodo di Versuta, Valvasone e Ciampino (1944-1955). L'obiettivo è di dimostrare che Pasolini fu ''eretico' anche nei suoi esperimenti di insegnamento, dichiarandosi a favore di una scuola non convenzionale e quindi alternativa ai metodi pedagogici tradizionali. Ne consegue che la natura "contraddittoria" dello scrittore si riflette nella sua vocazione educativa, che non rimane limitata al contesto scolastico ma riguarda l'intera società italiana, diventando un esempio di "pedagogia di massa". L'idea di una scuola da riformare collegandola alla vita è il principale lascito di Pasolini come educatore, che dovrebbe essere valorizzato dalle attuali politiche scolastiche
Raster-Atomic force nanolithography: New insights towards the fabrication of 3D nanostructures on PMMA and Silicon Nitride
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Variability in computer-aided detection effect on adenoma detection rate in randomized controlled trials: A meta-regression analysis
No full textBackground: Computer-aided detection (CADe) systems may increase adenoma detection rate (ADR) during colonoscopy. However, the variable results of CADe effects in different RCTs warrant investigation into factors influencing these results. Aims: Investigate the different variables possibly affecting the impact of CADe-assisted colonoscopy and its effect on ADR. Methods: We searched MEDLINE, EMBASE, and Scopus databases until July 2023 for RCTs reporting performance of CADe systems in the detection of colorectal neoplasia. The main outcome was pooled ADR. A random-effects meta-analysis was performed to obtain the pooled risk ratios (RR) with 95 % confidence intervals (CI)). To explore sources of heterogeneity, we conducted a meta-regression analysis using both univariable and multivariable mixed-effects models. Potential explanatory variables included factors influencing adenoma prevalence, such as patient gender, age, and colonoscopy indication. We also included both key (ADR), and minor (Withdrawal time) performance measures considered as quality indicators for colonoscopy. Results: Twenty-three randomized controlled trials (RCTs) on 19,077 patients were include. ADR was higher in the CADe group (46 % [95 % CI 39-52]) than in the standard colonoscopy group (38 % [95 % CI 31-46]) with a risk ratio of 1.22 [95 % CI 1.14-1.29]); and a substantial level of heterogeneity (I2 = 67.69 %). In the univariable meta-regression analysis, patient age, ADR in control arms, and withdrawal time were the strongest predictors of CADe effect on ADR (P < .001). In multivariable meta-regression, ADR in control arms, and withdrawal time were simultaneous significant predictors of the proportion of the CADe effect on ADR. Conclusion: The substantial level of heterogeneity found appeared to be associated with variability in colonoscopy quality performances across the studies, namely ADR in control arm, and withdrawal time
What is the benefit of endoscopic ultrasound-guided gastrojejunal anastomosis for patients with benign gastric outlet obstruction? A systematic review with meta-analysis
No full textBackground: Gastric outlet obstruction for benign indications (bGOO) is an uncommon condition, typically treated with surgery when medical therapy or endoscopic treatments fail. At present, endoscopic ultrasound (EUS)-guided gastrojejunostomy (GJ) may prove to be an effective alternative. Aims: We performed a systematic review with meta-analysis evaluating outcomes of EUS-GJ for bGOO. Methods: A comprehensive search was conducted up to February 2025. Pooled estimates were obtained using a random-effects model. Study quality was evaluated using the Newcastle-Ottawa quality scale. Heterogeneity was evaluated with I2 statistic. Technical success, clinical success, recurrence rate, and adverse events (AE) rate were the main outcomes. Results: Fifteen (15) studies, including a total of 376 patients, were identified. Pooled technical success was 95.8 % (CI 95 %, 93.8 %-97.8 %, I2 =0 %), while clinical success was 93.4 % (CI 95 %, 90.4 %-96.5 %, I2= 31.83 %). Pooled recurrence rate was 11.6 % (CI 95 %, 5.5 %-17.7 %, I2=32.36 %). The pooled rate of AE was 11.6 % (CI 95 %, 6.8-16.5 %, I2 = 57.18 %). Subgroup analyses found differences in safety when AE classification was used (17 % use vs. 6 % no use, p = 0.02) and based on quality of studies (low 22 % vs. moderate 10 % vs. high 3 %, p = 0.04). Conclusion: In conclusion, our findings show that EUS-GJ is effective and safe in those patients with bGOO in whom other endoscopic treatments fail, and surgery is not an option or could be performed as bridge-to-surgery. Our results suggest that safety is influenced by the use of AE classification and the quality of studies
Revolutionizing radiotherapy: gold nanoparticles with polyphenol coating as novel enhancers in breast cancer cells—an in vitro study
Get PDFBreast cancer is the most common cancer among women, with over 1 million new cases and around 400,000 deaths annually worldwide. This makes it a significant and costly global health challenge. Standard treatments like chemotherapy and radiotherapy, often used after mastectomy, show varying effectiveness based on the cancer subtype. Combining these treatments can improve outcomes, though radiotherapy faces limitations such as radiation resistance and low selectivity for malignant cells. Nanotechnologies, especially metallic nanoparticles (NPs), hold promise for enhancing radiotherapy. Gold nanoparticles (AuNPs) are particularly notable due to their high atomic number, which enhances radiation damage through the photoelectric effect. Studies shown that AuNPs can act as effective radiosensitizers, improving tumor damage during radiotherapy increasing the local radiation dose delivered. Traditional AuNPs synthesis methods involve harmful chemicals and extreme conditions, posing health risks. Green synthesis methods using plant extracts offer a safer and more environmentally friendly alternative. This study investigates the synthesis of AuNPs using Laurus nobilis leaf extract and their potential as radiosensitizers in breast carcinoma cell lines (MCF-7). These cells were exposed to varying doses of X-ray irradiation, and the study assessed cell viability, morphological changes and DNA damage. The results showed that green-synthesized AuNPs significantly enhanced the therapeutic effects of radiotherapy at lower radiation doses, indicating their potential as a valuable addition to breast cancer treatment