Frequency and temperature dependence of actuating performance of Bi1/2Na1/2TiO3-BaTiO3 based relaxor/ferroelectric composites

Recently, composites of relaxors (matrix) and either ferroelectric or nonergodic relaxor (seed) were proposed as a solution to resolving one of the main drawbacks of incipient piezoceramics, namely the requirement for high driving electric fields. In this study, we investigate the temperature and frequency dependence of the actuating performance of Bi1/2Na1/2TiO3-BaTiO3-based composites. Apart from the reduction of driving field, the composite architecture offers an extra degree of freedom for tailoring the temperature stability for different operational conditions for actuators. High strain values appear to be sensitive especially to driving frequency. This is originated by the time-dependent process of the coalescence of polar nanoregions. In effect, proximity of driving field and poling field leads to high strain sensitivity. Hence, the driving electric field needs to be adjusted in order to meet the desired frequency specifications for given applications.open0

2015-16 Antarctic Travel Project data set

During the 2015-2016 season, links to an internet survey were distributed to Antarctic travelers traveling with two different tour companies with expedition ships leaving from Ushuaia, Argentina, A paper brochure was placed in the expedition ship cabins of tourists before their arrival, and expedition staff gave reminders to complete them. 175 travelers, largely from two ships, completed this internet survey through Qualtrics. Tourists received links to the survey from expedition leaders who volunteered to distribute paper explanations of the survey with the link, including one author of the study (Roedel). This document gives the questions from the Qualtrics survey and the compiled results. Individual responses are not provided in order to preserve confidentiality. Some of the survey questions were taken from other, larger surveys in the hopes of producing comparable data. Those surveys, and their corresponding questions, are indicated in the Block Titles. Responses were collected between December 21, 2015 and March 8, 2016, a timeframe that corresponds to the Antarctic tourism season

2017-18 Antarctic Travel Project data set

For the 2017-2018 season, we distributed paper surveys to travelers on expedition ships leaving from Ushuaia, Argentina for the Antarctic peninsula. That instrument is included here. We received 362 responses, which is the n throughout the dataset. “Unanswered” indicates that nothing was written on the survey instrument for that question. The Ushuaia Tourism Office, INFUETUR, graciously assisted us in distributing surveys to the expedition guides. Guides then distributed the surveys to their passengers onboard, collected completed surveys, and returned them to the INFUETUR office. These were then mailed to the authors to be analyzed. Once the paper responses were received at Bucknell University, the data was entered into Qualtrics for analysis by Alex Busato. Responses were collected between December 2017 and February 2018, a timeframe that corresponds to the Antarctic tourism season

2018-19 Antarctic Travel Project data set

For the 2018-2019 season, we distributed paper surveys to travelers on expedition ships leaving from Ushuaia, Argentina for the Antarctic peninsula. That instrument is included here. We received 461 responses. The Ushuaia Tourism Office, INFUETUR, graciously assisted us in distributing surveys to the expedition guides. Guides then distributed the surveys to their passengers onboard, collected completed surveys, and returned them to the INFUETUR office. These were then mailed to the authors to be analyzed. We offer our deep thanks to all those who assisted with this survey! Responses were collected between December 2018 and February 2019, a timeframe that corresponds to the Antarctic tourism season

Tailoring Strain Properties of (0.94-x)Bi1/2Na1/2TiO3-0.06BaTiO(3)-xK(0.5)Na(0.5)NbO(3) Ferroelectric/Relaxor Composites

A remarkable progress in the quest of lead-free piezoceramics for actuator applications has been made with the development of incipient piezoceramics featured by giant strains. A drawback, however, is the high electric field required to generate this giant strain. A powerful approach to overcoming this drawback lies in relaxor/ferroelectric (FE) composites comprised such giant strain materials (matrix) and a FE or nonergodic relaxor (seed). In this study, we investigate the effect of K0.5Na0.5NbO3 content in the matrix and the volume ratio of seed to matrix using composites of 0.93Bi(1/2)Na(1/2)TiO(3)-0.07BaTiO(3) as a seed and (0.94-x)Bi1/2Na1/2TiO3-0.06BaTiO(3)-xK(0.5)Na(0.5)NbO(3) as a matrix. The strain of all matrices, independent of their K0.5Na0.5NbO3 content, was found to be enhanced by adding a certain amount of seed. An optimum strain is achieved for the composite comprised of a matrix with x=0.02 K0.5Na0.5NbO3 and 10% seed. By means of a differential analysis on the temperature-dependent dielectric permittivity, it was shown that the seed phase is still present in the composites despite the naturally expected diffusion process during sintering.close1

Giant electric-field-induced strains in lead-free ceramics for actuator applications - status and perspective

In response to the current environmental regulations against the use of lead in daily electronic devices, a number of investigations have been performed worldwide in search for alternative piezoelectric ceramics that can replace the market-dominating lead-based ones, representatively Pb(Zr (x) Ti1-x )O-3 (PZT)-based solid solutions. Selected systems of potential importance such as chemically modified and/or crystallographically textured (K, Na)NbO3 and (Bi1/2Na1/2)TiO3-based solid solutions have been developed. Nevertheless, only few achievements have so far been introduced to the marketplace. A recent discovery has greatly extended our tool box for material design by furnishing (Bi1/2Na1/2)TiO3-based ceramics with a reversible phase transition between an ergodic relaxor state and a ferroelectric with the application of electric field. This paired the piezoelectric effect with a strain-generating phase transition and extended opportunities for actuator applications in a completely new manner. In this contribution, we will present the status and perspectives of this new class of actuator ceramics, aiming at covering a wide spectrum of topics, i.e., from fundamentals to practice.close776

Circulating biomarkers in familial cerebral cavernous malformation

Background Cerebral Cavernous Malformation (CCM) is a rare cerebrovascular disease, characterized by the presence of multiple vascular malformations that may result in intracerebral hemorrhages (ICHs), seizure(s), or focal neurological deficits (FND). Familial CCM (fCCM) is due to loss of function mutations in one of the three independent genes KRIT1 (CCM1), Malcavernin (CCM2), or Programmed Cell death 10 (PDCD10/CCM3). The aim of this study was to identify plasma protein biomarkers of fCCM to assess the severity of the disease and predict its progression.Methods Here, we have investigated plasma samples derived from n = 71 symptomatic fCCM patients (40 female/31 male) and n =17 healthy donors (HD) (9 female/8 male) of the Phase 1/2 Treat_CCM trial, using multiplexed protein profiling approaches.Findings Biomarkers as sCD14 (p = 0.00409), LBP (p = 0.02911), CXCL4 (p = 0.038), ICAM-1 (p = 0.02013), ANG2 (p = 0.026), CCL5 (p = 0.00403), THBS1 (p = 0.0043), CRP (p = 0.0092), and HDL (p = 0.027), were significantly different in fCCM compared to HDs. Of note, sENG (p = 0.011), THBS1 (p = 0.011) and CXCL4 (p = 0.011), were correlated to CCM genotype. sROBO4 (p = 0.014), TM (p = 0.026) and CRP (p = 0.040) were able to predict incident adverse clinical events, such as ICH, FND or seizure. GDF-15, FLT3L, CXCL9, FGF-21 and CDCP1, were identified as predictors of the formation of new MRI-detectable lesions over 2-year follow-up. Furthermore, the functional relevance of ang2, thbs1, robo4 and cdcp1 markers was validated by zebrafish pre-clinical model of fCCM.Interpretation Overall, our study identifies a set of biochemical parameters to predict CCM progression, suggesting biological interpretations and potential therapeutic approaches to CCM disease

The RENAISSANCE (AIO-FLOT5) trial: effect of chemotherapy alone vs. chemotherapy followed by surgical resection on survival and quality of life in patients with limited-metastatic adenocarcinoma of the stomach or esophagogastric junction – a phase III trial of the German AIO/CAO-V/CAOGI

Abstract Background Historical data indicate that surgical resection may benefit select patients with metastatic gastric and gastroesophageal junction cancer. However, randomized clinical trials are lacking. The current RENAISSANCE trial addresses the potential benefits of surgical intervention in gastric and gastroesophageal junction cancer with limited metastases. Methods This is a prospective, multicenter, randomized, investigator-initiated phase III trial. Previously untreated patients with limited metastatic stage (retroperitoneal lymph node metastases only or a maximum of one incurable organ site that is potentially resectable or locally controllable with or without retroperitoneal lymph nodes) receive 4 cycles of FLOT chemotherapy alone or with trastuzumab if Her2+. Patients without disease progression after 4 cycles are randomized 1:1 to receive additional chemotherapy cycles or surgical resection of primary and metastases followed by subsequent chemotherapy. 271 patients are to be allocated to the trial, of which at least 176 patients will proceed to randomization. The primary endpoint is overall survival; main secondary endpoints are quality of life assessed by EORTC-QLQ-C30 questionnaire, progression free survival and surgical morbidity and mortality. Recruitment has already started; currently (Feb 2017) 22 patients have been enrolled. Discussion If the RENAISSANCE concept proves to be effective, this could potentially lead to a new standard of therapy. On the contrary, if the outcome is negative, patients with gastric or GEJ cancer and metastases will no longer be considered candidates for surgical intervention. Trial registration The article reports of a health care intervention on human participants and is registered on October 12, 2015 under ClinicalTrials.gov Identifier: NCT02578368 ; EudraCT: 2014–002665-30