Viscoelastic Characterization and Degradation Stability Investigation of Poly(butylene-adipate-co-terephthalate) - Calcium-Phosphate Glass Composites

In this work new biodegradable composite materials based on poly(butylene-adipate-co-terephthalate) (PBAT) reinforced with water-soluble calcium-phosphate glass (CPG) microparticles at different filler concentration (0, 4, 10, 20 and 40 wt%) were characterized by dynamic-mechanical analysis (DMA), aging and fragmentation tests. DMA results showed increasing storage modulus (E') values with the filler content, without a significant modification of the glass transition temperature (Tg), translating in a reinforcing effect of the filler particles with good interphase adhesion. The creep compliance decreased with the increase of the CPG content, confirming a greater resistance of the composites to deformation under constant stress. The stability to weathering agents and the degree of fragmentation in laboratory-scale composting conditions were also tested, obtaining a higher sensitivity to degradation of the PBAT-based composites with the increase of CPG content. Overall, the addition of CPG particles in a PBAT matrix produced stiffer composites, with modulation of the properties based on the filler content, enhancing at the same time their degradation rate, making them a promising and more sustainable alternative to traditional polymers

Patients’ reports on their delusional memories from the intensive care unit: A systematic review of qualitative studies

Objective: To critically summarise the qualitative literature to understand patients’ experiences of delusional memories during their Intensive Care Unit stay. Research methodology: A systematic review of qualitative studies with meta-synthesis and meta-summary. We searched MEDLINE (via PubMed), Cumulative Index to Nursing and Allied Health Literature (CINAHL), Scopus, and Web of Science to July 2022. All studies that provided qualitative insights into the subjective experience of adult patients with delusional memories in the Intensive Care Unit were selected. The Critical Assessment Skills Programme checklist was used for the quality assessment. Results: Fourteen studies were included. The 33 codes that emerged from the inductive thematic analysis were grouped into three themes: ‘The sense of danger and the terrifying aspect of death’ (feeling in danger, surrounded by death, persecuted by people around, and feeling unsafe), ‘The presence of someone or something nearby’ (perceiving the loved ones, feeling overwhelmed by scary creatures, and being neglected by those around me), and ‘The reality behind the world perceived by the senses’ (travelling the world, stimulating the senses, feeling peaceful, and living in a fantasy world). The most frequent code in the studies was ‘Be with a family member’, with an intensity of 35.7%. Conclusion: The patient's experience described as delusional is considered a real event by the person experiencing it. Further research is needed to investigate the extent to which these experiences lead to poorer early and late outcomes for patients, and to test strategies to prevent this. Implications for clinical practice: A deeper understanding of the phenomenon may help healthcare professionals to recognise precursors, symptoms and consequences of delusional memories and intervene with appropriate help. One strategy would be to further humanise care and focus on family involvement and communication with patients to overcome the factual events that can potentially alter patients’ quality of life

Posterior arch defect of the atlas associated to absence of costal element of foramen transversarium from 16th century Sardinia (Italy)

Study Design. A paleopathological case of posterior arch defect of the atlas associated to the absence of costal element of the foramen transversarium. Objective. In living patients as well as in postmortem analysis it should be difficult to distinguish between a congenital and an acquired anomaly. Any anomaly in the anatomy of atlas should be taken into consideration by clinicians, surgeons, radiologists, and anatomists in order to avoid misinterpretations and clinical complications. Summary of Background Data. Posterior arch defect has a current occurrence of approximately 4%. Posterior arch schisis is attributed to the defective or absent development of the cartilaginous preformation of the arch rather than a disturbance of the ossification. The absence of costal element of the foramen transversarium has an incidence of ranging from 2% to 10% and is attributed to a developmental defect or to variations in the course of the vertebral artery. Methods. The skeleton of a man aged 20–30 years, brought to light in the plague cemetery of 16th century Alghero (Sardinia), showed anomalies of the atlas, consisting in failure of the midline fusion of the 2 hemiarches with a small gap and an open anterior foramen trasversarium on the left side. A macroscopic, radiological, and stereomicroscopic study was carried out. Results. The study allowed to rule out a traumatic origin of the defects and to diagnose an association of 2 congenital anomalies. Conclusion. Osteoarchaeological cases provides with a valuable opportunity to examine and describe variations in the anatomy of the atlas

Sustainable hydrogen production via LiH hydrolysis for unmanned air vehicle (UAV) applications

In the current study, an experimental approach for the further understanding of the LiH hydrolysis reaction for hydrogen production is considered. The experimental work has been undertaken under small scale conditions by utilising fixed bed reactors. The hydrolysis reaction has been studied at several oven temperatures (150 °C, 300 °C and 500 °C). The favourable driving potentials for the hydrolysis reactions were identified by the utilisation of the Gibbs free energy analysis. The main outcome of the study is the deceleration of the reaction pace due to the formation of the by-product layers during the reaction. At the initial stage, due to the contact of steam with the unreacted and fresh LiH surface, the reaction proceeds on a fast pace, while the formation of the layers tends to decelerate the diffusion of steam into the core of material, forcing the production step to be slower. The hydrogen yield was found to be more than 90% of the theoretical value for all the reaction temperatures. Finally, a scenario of a hybrid-electric propulsion system for Unmanned Aerial Vehicles (UAVs) including Li-ion battery, Proton Membrane Fuel Cell (PEMFC) and an on-board hydrogen production system based on LiH hydrolysis is introduced and studied

Novel PBAT-Based Biocomposites Reinforced with Bioresorbable Phosphate Glass Microparticles

Biocomposites based on poly(butylene adipate terephthalate) (PBAT) and reinforced with micro-particles of inorganic biodegradable phosphate glass (PG) at 2, 10, and 40 wt% are prepared and characterized from a mechanical and morphological point of view. Scanning electron microscope (SEM) images show a good dispersion of the PG micro-grains, even at high concentrations, in the PBAT matrix, resulting in homogeneous composites. Tensile and dynamic-mechanical tests, respectively, indicate that Young's and storage moduli increase with PG concentration. The reinforcement of PBAT aims at modifying and tailoring the mechanical and viscoelastic properties of the material to expand its application field especially in the food and agricultural packaging sector, thanks to the similarity of PBAT performance with polyethylene

Atlas occipitalisation associated with other anomalies in a 16th century skeleton from Sardinia (Italy)

Archaeological excavations carried out in the plague cemetery of 16th century Alghero (Sardinia) brought to light the skeleton of a male aged 35–45 years, showing anomalies of the atlas. A macroscopic and radiological study has been carried out. The first cervical vertebra is fused with the skull base, resulting in an occipitalisation of the atlas. Absence of the costal element of the left foramen transversarium, resulting in an open anterior foramen transversarium, and posterior arch defect are also observed. The atlanto-occipital junction is a complex structure, susceptible to develop different patterns of congenital defects. These anatomical variations of atlas should be considered in modern clinical practice in order to formulate a correct diagnosis and to conceive an appropriate treatment. Osteoarchaeological cases are important as, beside to ascertain the presence of congenital defects in past populations, allow an in-depth study in dry bones, which can help modern medicine in interpreting anatomical variations. We present an association of congenital anomalies of the atlanto-occipital junction, a condition rarely documented in ancient and modern human skeletal remains

Investigating femtosecond laser interaction with tellurite glass family

Focusing ultrafast laser pulses induce localized permanent structural modifications on the surface or in transparent materials, that are of particular interest for photonic applications. Among the materials of interest, the tellurite glass family is attractive for near-infrared and photonics applications due to its broad-transparency window and high optical nonlinearity. Here, we systematically investigate structural changes occurring in various TeO2-based glasses exposed to femtosecond laser with various laser parameters. Remarkably, in a regime where heat accumulated after successive pulses, we observed the formation of polarization-controlled self-organized patterns expanding well beyond the focal volume, suggesting the presence of an evanescent coupling mechanism enhancing the self-organization. In addition, our results, obtained with compositional elemental analysis coupled with Raman spectra suggest different ion migration mechanisms in the laser affected zone at the surface and inside the glass. The formation of crystalline tellurium (t-Te) from glass structural units due to photo-induced elemental dissociation was observed only at the surface. The formation of ultrathin layer of crystalline tellurium offers the possibility to explore structural transitions in two-dimensional (2D) glasses by observing changes in the short- and medium- range structural orders, induced by spatial confinement

Single-frequency, pulsed Yb3+-doped multicomponent phosphate power fiber amplifier

High-power, single-frequency, pulsed fiber amplifiers are required in light detection and ranging, coherent laser detection, and remote sensing applications to reach long range within a short acquisition time. However, the power-scaling of these amplifiers is limited by nonlinearities generated in the optical fibers, in particular by stimulated Brillouin scattering (SBS). In this regard, the use of multicomponent phosphate glasses maximizes the energy extraction and minimizes nonlinearities. Here, we present the development of a single-stage, hybrid, pulsed fiber amplifier using a custom-made multicomponent Yb-doped phosphate fiber. The performance of the phosphate fiber was compared to a commercial Yb-doped silica fiber. While the latter showed SBS limitation at nearly 6.5 kW for 40 cm length, the maximum achieved output peak power for the multicomponent Yb-doped phosphate fiber was 11.7 kW for 9 ns pulses using only 20 cm with no sign of SBS

‘Coming back Home’ . Il Modello Virtuale della Statua Romana di Asclepio del Museo di Siracusa (Italia)

The colossal torso of the god Asclepius, kept into the Castello Maniace during the Spanish domination of Sicily, is now one of the most significant examples of roman statuary in the Syracuse Museum. The recent restoration of the Castello Maniace has been celebrated in 2008 with an exhibition of archaeological finds obtained in the various excavations of the castle. The statue of Asclepius, which had for centuries been a part of the architecture there, should have been the most significant piece on display. However, its large size and frailty made such a temporary move inadvisable, and it was decided that a plaster cast should be made and exhibited instead. A team of archaeologists and information technicians from the Archeomatica Project of Catania University were able to contribute to this task by creating a 3D model of the statue through the use of laser scanning techniques