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Multilevel structural health monitoring of real scale aerostructures using guided waves
No full textThis paper presents the implementation of a multi-level structural health monitoring approach on a real scale wing box affected by barely visible impact damage. Integrated sensors data is considered to systematically design a comprehensive structural health monitoring system for impact detection and related-damage characterization in complex aerostructures. The conceived approach relies on an integrated and optimized acquisition system and a multi-level diagnosis algorithm, including impact detection as well as damage identification, localization and sizing. The use of different excitation and sensing smart points deployed all over the wing structures is explored towards continuous health management. The first results using piezoelectric transducers and guided ultrasonic waves for damage detection and localization are discussed, showing the promising approach in detecting low velocity impacts as well as characterizing barely visible damage
An Interior Regularity Property for the Solution to a Linear Elliptic System with Singular Coefficients in the Lower-Order Term
No full textThis paper deals with the interior higher differentiability of the solution u to the Dirichlet problem related to system
on a bounded lipschitz domain in . The matrix lies in the John and Nirenberg space .
The lower order term is controlled with respect to spatial variable by a function belonging to the Marcinkiewicz space . The novelty here is the presence of a singular coefficient in the lower order term
α-Olefin Oligomerization Mediated by Group 4 Metallocene Catalysts: An Extreme Manifestation of the Multisite Nature of Methylaluminoxane
No full textGroup 4 metallocenes are competent catalysts for the oligomerization of higher α-olefins. Among the many chemical and physical variables of importance in the process, one is the choice of cocatalyst (activator). The impact of various activators on the performance of a representative catalyst, (nBuCp)2ZrCl2, in the oligomerization of 1-octene was thoroughly investigated; in particular, the molecular weight distribution (MWD) of the oligomers was determined by means of high-resolution high performance liquid chromatography (HR-HPLC). Unexpectedly, a bimodal MWD was highlighted when the precatalyst was activated with methylaluminoxane (MAO), whereas a single Schulz–Flory (SF) MWD was observed with borate salts. The presence of Al centers with different Lewis acidity in the complex and ill-defined structure of MAO is well known, and the broadening effects on the MWD of olefin polymerization products made with metallocene/MAO catalyst systems have been reported before. However, to the best of our knowledge, clear HR-HPLC evidence of two active species resulting from activation with MAO of one single zirconocene precursor, yielding two discrete SF product distributions, is unprecedented. By varying the polarity of the reaction medium, we managed to modulate the MWD of the oligomers from bimodal to monomodal, even with MAO, thus demonstrating that ion pairing effects are behind these unusual findings
Analyzing food waste perceptions and its solutions: A pilot study on a non-WEIRD sample.
No full textAnticancer Attributes and Multifaceted Pharmacological Implications of Laetrile and Amygdalin
No full textLaetrile, known as vitamin B17, is often used interchangeably with amygdalin. Laetrile is a semi‐synthesis product of amygdalin,
whereas amygdalin is a naturally occurring substance in many plants. Both compounds have a nitrile functional group
that, when activated by the intestinal enzyme β‐glucosidases, releases hydrogen cyanide. The two compounds have been
considered for a long time as alternative therapy for cancer treatment however, findings available in the literature are discordant
on the real efficacy of laetrile/amygdalin for the treatment of cancer, often highlighting a negative benefit‐risk ratio.
In this regard, the study aimed to comprehensively analyze the scientific data on laetrile/amygdalin, with a special emphasis
on their pharmacokinetics, underlying pharmacological properties, mode of action as a potent antitumor agent, and effect on
human health. The results showed that there is no clear evidence on the efficacy of cancer therapy following laetrile/amygdalin
administration, especially at the clinical trial level. However, the in vitro studies of the biological activity of these compounds
showed positive effects related to their antifibrotic, anti‐inflammatory, antiasthmatic, and immunoregulatory processes. Laetrile's
mechanism of action closely resembles amygdalin, affecting cancer signaling pathways. However, due to its cyanide
toxicity, it was banned by the food and drug administration (FDA) due to safety concerns. Despite not receiving permission
from the FDA, laetrile emerged as an alternative therapy in the 1970s. Nonetheless, continuing research is investigating safer methods of activating Laetrile for targeted cancer treatment. This opens interesting prospects in using these compounds in
alternative medical therapies, for which, however, further research is needed
Gut microbiome profiles and associated functional pathways are linked to Mediterranean diet adherence and blood glucose control in adults with type 1 diabetes mellitus
No full text1. Background and Aims
The Mediterranean diet (MD) has been associated with better glycaemic control in children with type 1 diabetes mellitus (T1DM) and favourable microbiome profiles in healthy individuals. However, it remains unclear whether MD adherence is associated with glycaemic control via microbiome. This study examined the relationships among MD adherence, gut microbiome, and glycaemic control in adults with T1DM and assessed the microbiome’s ability to predict clinical and dietary outcomes.
2. Methods and Results
In a cross-sectional study of 253 adults with T1DM, dietary intake was assessed using the EPIC food frequency questionnaire, and MD adherence was measured using the rMED score. Participants were stratified by adherence level (low, medium, high). Glycaemic control was evaluated using HbA1c and CGM metrics. Shotgun metagenomic sequencing of stool samples (n=103) assessed the gut microbiome. Statistical analyses included ANOVA, PERMANOVA, LEfSe, and machine learning modeling. Higher MD adherence was associated with lower HbA1c levels (7.1% vs 7.7%; p<0.001), greater time in range (67.0% vs 59.4%; p-trend=0.03), and higher HDL cholesterol (1.62 vs 1.39 mmol/L; p=0.01). High MD adherence was linked to a greater abundance of bacterial species such as Faecalibacterium prausnitzii. Both high MD adherence and lower HbA1c were associated with distinct microbiome functional pathways. Microbiome-based machine learning models predicted dietary patterns and clinical metrics.
3. Conclusions
In adults with T1DM, greater MD adherence is associated with better glycaemic control and a favourable gut microbiome. Specific microbial pathways may underlie these associations. Integrating diet and microbiome data supports personalized care.
The study was registered at ClinicalTrials.gov with the identifier NCT05936242
Innovative agrivoltaic systems: integrated solutions for climate resilient habitats
No full textInnovation in the field of agrivoltaic systems involves the adoption of integrated solutions aimed at preserving the continuity of agricultural cultivation activities by applying convergent technologicalenergy innovations on the one hand, and technological-cultural innovations on the other. Agrivoltaic systems can be framed in the category of biotech integrated systems, and their implementation looks at innovative climate resilient habitat models, favouring a compatible combination of anthropic and environmental components. The paper reports on the outcomes of the activity of a research group of the Department of Architecture, University of Naples Federico II, conducted in the framework of the integrated project ‘High-efficiency photovoltaics’ (PTR 2022-2024), The aim was to define support tools for environmental sustainability in the design of agrivoltaic systems, starting from the construction of a systematised framework of the main aspects of the technological innovation in its orientation towards increasing climate resilience
Triangulation of Space-based Optical Measurements for Improved Space Surveillance and Tracking
No full textThe growing number of Resident Space Objects (RSOs) poses a serious threat to the safety of satellites and the long-term sustainability of space activities. The current knowledge of the RSOs is mainly based on ground-based instruments including telescopes, radar and laser systems. To augment sensor networks capabilities and to go beyond some limitations of terrestrial systems, several satellites for space-based observations have been launched in the last decades. Indeed, space-based sensors offer unique advantages with respect to the ground-based counterparts, enabling more frequent and clear observations of RSOs, overcoming visibility limitations due to geographical constraints and avoiding issues related to local weather conditions and environmental and atmospheric effects.
Optical sensors are the preferred technology for space-based RSOs monitoring, due to their small size and lower power requirements compared to radar and laser systems. However, unlike radar and laser systems, a single optical sensor only provides angular measurements, without the possibility of measuring the range from the object. Indeed, simultaneous measurements provided by two or more optical sensors can be used to determine the range and, thus, the 3D position of space debris by means of triangulation methods.
As an example, the obtained range information enables to improve the accuracy of the initial orbit determination (IOD), which is of paramount importance for space debris cataloguing. Indeed, when dealing with space-based observations, the results of the angles-only IOD generally have large errors, as the observed arcs are too short and lack range information. Therefore, based on triangulation with two optical sensors, the angles-only IOD problem can be converted to IOD using 3D position data, thus significantly improving IOD accuracy.
While this methodology is well assessed in the literature for ground-based sensors [1], this paper addresses the problem considering space-based sensors. The envisaged scenario concerns the exploitation of distributed systems for space-based space surveillance. Basic observation constraints and operational aspects, such as sensor tasking and data association, are addressed. Simultaneous angles-only measurements provided by different space-based optical sensors are used to support IOD using approaches that exploit knowledge of position vectors. A sensitivity analysis is conducted to evaluate how the different configurations of the space-based sensors with respect to the observed RSO, and the non idealities of the measurement process, affect the accuracy of range and orbit determination. The analysis is conducted on simulated test cases exploiting realistic orbit propagation and measurement simulation (including RSO detectability)
