Effect of thermal depolarization on the poling‐induced domain texture and piezoelectric properties in Mg‐doped NBT‐6BT

Recently, poled Na₀.₅₀Bi₀.₅₀TiO₃‐BaTiO₃ (NBT‐BT)‐based polycrystalline materials have been characterized as possessing a high degree of poling‐induced domain texture in their remanent state. This finding is suggested to be the reason for their stable mechanical quality factor at high‐vibration velocity, making them promising candidates for high‐power applications. The materials in consideration are prone to self‐heating and thermal run‐away, particularly at slightly elevated temperatures. Therefore, this paper evaluates the temperature dependence of the poling‐induced domain texture of (Na₀.₄₇Bi₀.₄₇Ba₀.₀₆)TiO₃ (NBT‐6BT) doped with 0.5 mol% of Mg as compared to undoped NBT‐6BT. Its influence on small‐signal, large‐signal, and high‐power properties was investigated. To obtain a fundamental understanding of crystal structure, in‐situ synchrotron measurements were conducted as function of temperature to establish a relationship between structure and piezoelectric properties of both Mg‐doped and undoped NBT‐6BT materials

Marine phycotoxin levels in shellfish-14 years of data gathered along the Italian coast

Along the Italian coasts, toxins of algal origin in wild and cultivated shellfish have been reported since the 1970s. In this study, we used data gathered by the Veterinary Public Health Institutes (IZS) and the Italian Environmental Health Protection Agencies (ARPA) from 2006 to 2019 to investigate toxicity events along the Italian coasts and relate them to the distribution of potentially toxic species. Among the detected toxins (OA and analogs, YTXs, PTXs, STXs, DAs, AZAs), OA and YTX were those most frequently reported. Levels exceeding regulatory limits in the case of OA (≤2,448 μg equivalent kg-1) were associated with high abundances of Dinophysis spp., and in the case of YTXs (≤22 mg equivalent kg-1) with blooms of Gonyaulax spinifera, Lingulodinium polyedra, and Protoceratium reticulatum. Seasonal blooms of Pseudo-nitzschia spp. occur all along the Italian coast, but DA has only occasionally been detected in shellfish at concentrations always below the regulatory limit (≤18 mg kg-1). Alexandrium spp. were recorded in several areas, although STXs (≤13,782 μg equivalent kg-1) rarely and only in few sites exceeded the regulatory limit in shellfish. Azadinium spp. have been sporadically recorded, and AZAs have been sometimes detected but always in low concentrations (≤7 μg equivalent kg-1). Among the emerging toxins, PLTX-like toxins (≤971 μg kg-1 OVTX-a) have often been detected mainly in wild mussels and sea urchins from rocky shores due to the presence of Ostreopsis cf. ovata. Overall, Italian coastal waters harbour a high number of potentially toxic species, with a few HAB hotspots mainly related to DSP toxins. Nevertheless, rare cases of intoxications have occurred so far, reflecting the whole Mediterranean Sea conditions

Toxin Levels and Profiles in Microalgae from the North-Western Adriatic Sea—15 Years of Studies on Cultured Species

The Northern Adriatic Sea is the area of the Mediterranean Sea where eutrophication and episodes related to harmful algae have occurred most frequently since the 1970s. In this area, which is highly exploited for mollusk farming, the first occurrence of human intoxication due to shellfish consumption occurred in 1989, nearly 10 years later than other countries in Europe and worldwide that had faced similar problems. Until 1997, Adriatic mollusks had been found to be contaminated mostly by diarrhetic shellfish poisoning toxins (i.e., okadaic acid and dinophysistoxins) that, along with paralytic shellfish poisoning toxins (i.e., saxitoxins), constitute the most common marine biotoxins. Only once, in 1994, a toxic outbreak was related to the occurrence of paralytic shellfish poisoning toxins in the Adriatic coastal waters. Moreover, in the past 15 years, the Adriatic Sea has been characterized by the presence of toxic or potentially toxic algae, not highly widespread outside Europe, such as species producing yessotoxins (i.e., Protoceratium reticulatum, Gonyaulax spinifera and Lingulodinium polyedrum), recurrent blooms of the potentially ichthyotoxic species Fibrocapsa japonica and, recently, by blooms of palytoxin-like producing species of the Ostreopsis genus. This review is aimed at integrating monitoring data on toxin spectra and levels in mussels farmed along the coast of the Emilia-Romagna region with laboratory studies performed on the species involved in the production of those toxins; toxicity studies on toxic or potentially toxic species that have recently appeared in this area are also reviewed. Overall, reviewed data are related to: (i) the yessotoxins producing species P. reticulatum, G. spinifera and L. polyedrum, highlighting genetic and toxic characteristics; (ii) Adriatic strains of Alexandrium minutum, Alexandrium ostenfeldii and Prorocentrum lima whose toxic profiles are compared with those of strains of different geographic origins; (iii) F. japonica and Ostreopsis cf. ovata toxicity. Moreover, new data concerning domoic acid production by a Pseudo-nitzschia multistriata strain, toxicity investigations on a Prorocentrum cf. levis, and on presumably ichthyotoxic species, Heterosigma akashiwo and Chattonella cf. subsalsa, are also reported

Monitoraggio dello stato di idratazione della pelle mediante misure di impedenza

Una buona idratazione è fondamentale per l’espletamento delle funzioni fisiologiche più elementari, come ad esempio la regolazione della pressione sanguigna, della temperatura corporea e della digestione. Quando il corpo perde più acqua di quanto ne assume si può verificare il fenomeno della disidratazione. La perdita eccessiva di fluidi può causare diversi squilibri nello stato fisico di un individuo fino a portare, in casi estremi, a condizioni fatali e i soggetti maggiormente a rischio sono: bambini, anziani e atleti. I metodi di indagine attualmente esistenti finalizzati a tale scopo sono sostanzialmente test di laboratorio (sangue, urine) che forniscono dati molto precisi, ma sono invasivi, costosi e non permettono di ottenere un’informazione real-time. Un fenomeno che sta prendendo piede in questi ultimi anni è lo sviluppo di sensori indossabili coi quali è possibile tenere sotto osservazione parametri quali la frequenza cardiaca e il consumo di calorie, ma ancora sono pochi o quasi del tutto assenti i dispositivi che possono fornire attendibili informazioni circa lo stato di idratazione di un soggetto. Obiettivo di questa tesi è quello di illustrare il prototipo di un sensore indossabile, realizzato in laboratorio, in grado di produrre proprio questo tipo di informazione, ossia capace di monitorare lo stato di idratazione di un soggetto in maniera real-time sulla base della misura dell’ impedenza offerta dal suo sudore cutaneo. L’impedenza misurata viene poi trasdotta in una misura di conducibilità tramite un sensore in grado di valutare la variazione della composizione del sudore durante l’esecuzione di un esercizio fisico. Il dispositivo realizzato è stato calibrato e testato in vitro utilizzando soluzioni che riproducono il sudore artificiale. Successivamente, è stato usato per effettuare misure in vivo su un soggetto durante l’esecuzione di un esercizio fisico al fine di valutarne il funzionamento come prototipo indossabile

Effect of thermal depolarization on the poling-induced domain texture and piezoelectric properties in Mg-doped NBT-6BT

Recently, poled Na0.50Bi0.50TiO3-BaTiO3 (NBT-BT)-based polycrystalline materials have been characterized as possessing a high degree of poling-induced domain texture in their remanent state. This finding is suggested to be the reason for their stable mechanical quality factor at high-vibration velocity, making them promising candidates for high-power applications. The materials in consideration are prone to self-heating and thermal run-away, particularly at slightly elevated temperatures. Therefore, this paper evaluates the temperature dependence of the poling-induced domain texture of (Na0.47Bi0.47Ba0.06)TiO3 (NBT-6BT) doped with 0.5 mol% of Mg as compared to undoped NBT-6BT. Its influence on small-signal, large-signal, and high-power properties was investigated. To obtain a fundamental understanding of crystal structure, in-situ synchrotron measurements were conducted as function of temperature to establish a relationship between structure and piezoelectric properties of both Mg-doped and undoped NBT-6BT materials

Additive Manufacturing of Piezoelectric Niobium-Doped Lead Zirconate Titanate (PZT-N) by Binder Jetting

Binder jetting is an emerging indirect additive manufacturing technique for ceramic materials, which could be employed to produce application-oriented designed components impossible to achieve with traditional processes and featuring enhanced performances. In our study, niobium-doped lead zirconate titanate (PZT-N) powder, usually processed through the standard press-and-sinter route, was employed as the raw material. First, the powder was characterized in terms of granulometry and flowability to assess its suitability for the printing process. Then, shaping by binder jetting was studied, and the effect of three levels of binder saturation (75–90–105%) on the green bodies was assessed. Finally, the microstructure of the sintered samples was studied using SEM, to investigate the effect of thermal treatments on the grain size distribution and residual porosity (~40%). The piezoelectric properties were measured and compared to those of conventionally processed material. The piezoelectric charge and voltage constants (d33 and g33) were evaluated to determine the possible use of printed parts as porous piezoelectric components to be exploited in hydrophones in the direct mode

Additive manufacturing of lead-free KNN by binder jetting

Additive manufacturing of lead-free piezoceramics is of great interest, given the large request of application-oriented designs with optimal performances and reduced material consumption. Binder Jetting (BJ) is an additive manufacturing technique potentially suited to the production of ceramic components, however the number of feasibility studies on BJ of piezoceramics is extremely limited and totally lacking in the case of sodium-potassium niobate (KNN). In this work, as-synthesised powders are employed in the BJ 3D printing process. Microstructural properties, such as porosity, grain size distributions, and phase composition are studied by SEM, XRD and MIP (Mercury Intrusion Porosimetry) and compared to die-pressed pellets. Analyses reveal considerable residual porosity (~40%) regardless of the printing parameters, with a weak preferential orientation parallel to the printing plane. The piezoelectric characterization demonstrates an outstanding d33 value of 80–90 pC N−1. Finally, Figures of Merits for the employment as porous piezoceramics in the direct mode are presented

Analysis of RBFOX1 gene expression in lymphoblastoid cell lines of Italian discordant autism spectrum disorders sib-pairs

Several lines of evidence suggest that RBFOX1 is a key regulator of transcriptional and splicing programs in neural cells during development, and that it is expressed in a neuronal module enriched for known autism susceptibility genes. We have investigated its expression by semiquantitative RT-PCR in accessible nonbrain resources in eighteen autism spectrum disorder sib-pairs belonging to the Italian Autism Network cohort. RBFOX1 gene expression was detected in lymphoblastoid cell lines but not in lymphocytes. No significant differences between autism spectrum disorders and non-affected brothers were found. We were not able to replicate in lymphoblastoid cell lines the previously reported RBFOX1 gene downregulation in autism, even if a trend was observed. This might be due to less pronounced transcription level differences in RBFOX1 gene expression in lymphoblastoid cell lines than in brain samples. \ua9 2014 Elsevier Ltd

Bortezomib-thalidomide-dexamethasone is superior to thalidomide- dexamethasone as consolidation therapy after autologous hematopoietic stem cell transplantation in patients with newly diagnosed multiple myeloma

In a randomized, phase 3 study, superior complete/near-complete response (CR/nCR) rates and extended progression-free survival were demonstrated with bortezomib-thalidomide-dexamethasone (VTD) versus thalidomide-dexamethasone (TD) as induction therapy before, and consolidation after, double autologous stem cell transplantation for newly diagnosed myeloma patients (intention-to-treat analysis; VTD, n = 236; TD, n = 238). This per-protocol analysis (VTD, n = 160; TD, n = 161) specifically assessed the efficacy and safety of consolidation with VTD or TD. Before starting consolidation, CR/nCR rates were not significantly different in the VTD (63.1%) and TD arms (54.7%). After consolidation, CR (60.6% vs 46.6%) and CR/nCR (73.1% vs 60.9%) rates were significantly higher for VTD-treated versus TD-treated patients. VTD consolidation significantly increased CR and CR/nCR rates, but TD did not (McNemar test). With a median follow-up of 30.4 months from start of consolidation, 3-year progression-free survival was significantly longer for the VTD group (60% vs 48% for TD). Grade 2 or 3 peripheral neuropathy (8.1% vs 2.4%) was more frequent with VTD (grade 3, 0.6%) versus TD consolidation. The superior efficacy of VTD versus TD as induction was retained despite readministration as consolidation therapy after double autologous transplantation. VTD consolidation therapy significantly contributed to improved clinical outcomes observed for patients randomly assigned to the VTD arm of the study. The study is registered at www.clinicaltrials.gov as #NCT01134484. \ua9 2012 by The American Society of Hematology