King post truss as a motif for internal structure of (meta)material with controlled elastic properties

One of the most interesting challenges in the modern theory of materials consists in the determination of those microstructures which produce, at the macro-level, a class of metamaterials whose elastic range is many orders of magnitude wider than the one exhibited by ‘standard’ materials. In Dell’Isola et al. (2015 Zeitschrift für angewandte Mathematik und Physik 66, 3473- 3498. (doi: 10.1007/s00033-015-0556-4)), it was proved that, with a pantographic microstructure constituted by ‘long’ microbeams it is possible to obtainmetamaterials whose elastic range spans up to an elongation exceeding 30%. In this paper, we demonstrate that the same behaviour can be obtained bymeans of an internal microstructure based on a king post motif. This solution shows many advantages: it involves only microbeams; all constituting beams are undergoing only extension or compression; all internal constraints are terminal pivots. While the elastic deformation energy can be determined as easily as in the case of long-beam microstructure, the proposed design seems to have obvious remarkable advantages: it seems to be more damage resistant and therefore to be able to have a wider elastic range; it can be realized with the same three-dimensional printing technology; it seems to be less subject to compression buckling. The analysis which we present here includes: (i) the determination of Hencky-type discrete models for king post trusses, (ii) the application of an effective integration scheme to a class of relevant deformation tests for the proposed metamaterial and (iii) the numerical determination of an equivalent second gradient continuum model. The numerical tools which we have developed and which are presented here can be readily used to develop an extensive measurement campaign for the proposed metamaterial

Geophysical characterisation of gas hydrate systems on the southern Hikurangi Margin of New Zealand

Gas hydrates act as an efficient natural sequester of large amounts of carbon, and it is estimated that approximately 15% of Earth's total mobile carbon could be stored in gas hydrate provinces. They form complex systems in the shallow sediments of deep-sea regions, where there is sufficient supply of natural gas along with the stability conditions of moderately low temperatures and high pressures. Most gas hydrate provinces are found on continental margins. The southern Hikurangi subduction margin, o_ Wairarapa (New Zealand), contains a large gas hydrate province, inferred by the presence of widespread bottom simulating reflections (BSR) in shallow sediments. Locally intense fluid seepage at the seafloor associated with methane hydrate has also been observed and documented. Understanding the complexity of hydrate systems is valuable for a range of scientific issues related to climate change and ocean chemistry, geological hazards, deep-sea ecology, and energy supply. A quantitative approach to the characterisation of gas hydrate systems in the region is an essential step towards the estimation of the local carbon budget, especially in terms of the total volume of gas hydrate in the region and estimation of gas fluxes through the seafloor at cold seep locations. In this thesis, I combine a range of geophysical data and theoretical models to identify, map and quantitatively characterise gas hydrate deposits and cold seeps on the southern Hikurangi Margin. Multi-channel seismic (MCS) data and methods form a large part of the basis of the studies presented in this thesis. Two MCS datasets were used: long-offset, lower resolution petroleum industry data APB13 (R/V Duke, 2013) and higher resolution, short-offset academic data TAN1808 (R/V Tangaroa, 2018), acquired as a densely spaced grid of lines over five target sites. The synthesis of these datasets provides a complementary basis for characterising concentrated gas hydrate deposits. The long-offset data allow retrieval of P-wave velocity information of the subsurface, whereas the higher resolution data enable detailed imaging of geologic features associated with gas hydrates and fluid flow. Hydroacoustic data were used to characterise the water column and to estimate methane fluxes from gas seeps related to the gas hydrate systems

Magnetoencephalography in Stroke Recovery and Rehabilitation

Magnetoencephalography (MEG) is a non-invasive neurophysiological technique used to study the cerebral cortex. Currently, MEG is mainly used clinically to localize epileptic foci and eloquent brain areas in order to avoid damage during neurosurgery. MEG might, however, also be of help in monitoring stroke recovery and rehabilitation. This review focuses on experimental use of MEG in neurorehabilitation. MEG has been employed to detect early modifications in neuroplasticity and connectivity, but there is insufficient evidence as to whether these methods are sensitive enough to be used as a clinical diagnostic test. MEG has also been exploited to derive the relationship between brain activity and movement kinematics for a motor-based brain-computer interface. In the current body of experimental research, MEG appears to be a powerful tool in neurorehabilitation, but it is necessary to produce new data to confirm its clinical utility

Nystagmus in Infantile Pompe Disease: a new feature?

We describe a 3 month-old female floppy infant with hypertrophic cardiomyopathy, serum en- zyme levels, which were characterized by an aspartate aminotransferase level of 144 U/l, alanine transaminase 240 U/L and creatine kinase level of 543 U/l. On the basis of the clinical signs and laboratory results, acid α-glucosidase activity was determined from dried blood spots resulting lower than the normal range (0.2 mmol/L/h: normal reference range: 1,86-21,9 mmol/L/h) and leading to a diagnosis of infantile Pompe dis- ease. She also showed multi-directional nystagmus. Refractive errors, ptosis and strabismus are described in infantile Pompe Disease, while nystagmus is rarely reported before. Therefore with this paper we highlight an atypical ocular symptom, whose uncertain pathogenesis, to be taken into consideration, because by now, with increasing survival with ERT, new phenotypes of Pompe disease are taking shap

Chronic NSAIDs Therapy and Upper Gastrointestinal Tract – Mechanism of Injury, Mucosal Defense, Risk Factors for Complication Development and Clinical Management

Non steroidal anti-inflammatory drugs (NSAIDs) are the most prescribed medications worldwide because of their analgesic and anti-inflammatory properties. In fact, NSAIDs are generally prescribed for pain management in musculoskeletal or osteoarticolar pathologies and for rheumatic diseases, very common diseases in the general population. About twenty million US patients were prescribed NSAIDs every year. Although NSAIDs are generally well tolerated, chronic therapy is responsible for a significant morbidity and mortality rate; in fact, the incidence of GI events is significantly higher (about four fold) in patients receiving NSAIDs chronic therapy. Adverse gastrointestinal events related to NSAIDs therapy occur in a little but significant amount of patients, resulting in an important morbidity and mortality. In the US more than 150 per 100.000 patients were admitted every year for NSAIDs related adverse events, resulting in about 15000 deaths. The chapter covers the mechanism of NSAIDs related injury, mucosal defense, risk factors for complication development and the clinical management

Artificial neural networks to predict the mechanical properties of natural fibre-reinforced Compressed Earth Blocks (CEBs)

The purpose of this study is to explore Artificial Neural Networks (ANNs) to predict the compressive and tensile strengths of natural fibre-reinforced Compressed Earth Blocks (CEBs). To this end, a database was created by collecting data from the available literature. Data relating to 332 specimens (Database 1) were used for the prediction of the compressive strength (ANN1), and, due to the lack of some information, those relating to 130 specimens (Database 2) were used for the prediction of the tensile strength (ANN2). The developed tools showed high accuracy, i.e., correlation coefficients (R-value) equal to 0.97 for ANN1 and 0.91 for ANN2. Such promising results prompt their applicability for the design and orientation of experimental campaigns and support numerical investigations.This work was funded by the FCT (Foundation for Science and Technology), under grant agreement UIBD/150874/2021 attributed to the first author. This work was also partly financed by Fundação “La Caixa”, under the reference PV20-00072, and FCT/MCTES through national funds (PIDDAC) under the R&D Unit Institute for Sustainability and Innovation in Structural Engineering (ISISE), under reference UIDB/04029/2020

SHEARING TESTS APPLIED TO PANTOGRAPHIC STRUCTURES

With the advancements in 3D printing technology, rapid manufacturing of fabric materials with complex geometries became possible. By exploiting this technique, different materials with different structures have been developed in the recent past with the objective of making generalized continuum theories useful for technological applications. So-called pantographic structures are introduced: Inextensible fibers are printed in two arrays orthogonal to each other in parallel planes. These superimposed planes are inter-connected by elastic cylinders. Five differently-sized samples were subjected to shear-like loading while their deformation response was analyzed. Results show that deformation behavior is strong non-linear for all samples. Furthermore, all samples were capable to resist considerable external shear loads without leading to complete failure of the whole structure. This extraordinary behavior makes these structures attractive to serve as an extremely tough metamaterial

Psychiatric Emergency in Children and Adolescents: A Retrospective Study in Parma Local Health Unit

The mental health care system in Italy is based on Law 180/70 which leaves great regional autonomy about the management of adolescent patients suffering from psychiatric diseases. The aim of this study is the evaluation of demographic, social, and clinical features of minors admitted to psychiatric wards, as starting point to improve individualized services for them. Data about all under 18s consecutively admitted to Parma’s psychiatric wards from 2013 to 2015 were retrospectively collected from medical records. Diagnoses were classified according to ICD-10 criteria, and statistical analysis was performed using SPSS statistical software (IBM SPSS Statistics 22.0) for Windows. Clinical samples include 51 cases, 30 males (mean age: 15.5 years, ranging from 12 to 17 years) and 21 females (mean age: 15.9, ranging from 14 to 17 years). The most frequent diagnosis is conduct disorder (39.2%), with higher prevalence among males. Following this, 23.5% of the patients present comorbidity issues and 9.8% suffer from personality disorders, which is more frequent among females. High percentages of foreigners (31.4%), adopted minors (15.7%), and drug users (40%) are reported. Furthermore, data reveal that unprotective family environment, registered in 80.4% of cases, plays an important role as risk factor for the development of mental disease, readmissions in psychiatric wards, and discharge to residential facilities. Readmissions, as well as compulsory treatments (11 cases), are mainly required in case of conduct disorders and comorbidity diagnosis. Lastly, in contrast with the situation before hospital admission, most patients (63.3%) are discharged and sent to community residential facilities. Findings can be useful to improve the management of psychiatric emergencies in minors, focusing on their specific needs, such as conduct disorders and substance abuse, and to face emerging challenges, for example, mental health disease associated with the growing phenomenon of immigration