Thermal Evolution of Dielectric and Piezoelectric properties of Lead-Free Submicron-Structured (Bi0.5Na0.5)0.94Ba0.06TiO3 Ceramics

The challenge to develop high piezoelectric sensitivity and lead-free compositions ferroelectric ceramics has bring new interest to the study of some classical ferroelectrics as (Bi0.5Na0.5)TiO3 and its solid solutions. The composition near the MPB of the system (1-x) (Bi0.5Na0.5)TiO3-xBaTiO3 with x=0.06 (BNBT6) was found to have interesting properties as lead-free piezoelectric ceramic. Processing of ceramics from nanopowders allows getting fine grained, submicron structured, ceramics that are of interest both for the basic studies of size-effects in ferroelectrics and for their use as high frequency ultrasonic transducers. Submicron-structured BNBT6 ceramics, obtained from nanometric powder synthesized by sol gel auto-combustion at 500?C, by hot-pressing at low temperature (700-800?C) and subsequent recrystallization at higher temperature, still moderate (<1100?C), in order to reduce loss of the volatile elements, have been studied. Elastic and piezoelectric coefficients, as well as electromechanical coupling factors, were determined at the resonances of, thickness poled, thin disks and shear plates. The best room temperature piezoelectric coefficient obtained in these BNBT6 fine-grained (~1&#956;m) ceramics (d33=148 pC.N-1, d31= -37 pC.N-1, d15=158 pC.N-1, kt= 40.4%, kp=26.8% and k15=40.2%) can be compared with those reported for coarse-grained ceramics prepared at higher sintering temperatures. The thermal evolution of the dielectric permittivity, piezoelectric coefficients and coupling factors has been also determined and compared with results reported for BNBT6 coarse grained ceramics, which showed a depolarization temperature of ~105?

Thermal depolarization of lead-free (Bi0.5Na0.5)0.94Ba0.06TiO3 piezoceramics monitored by shear resonance of thickness-poled plates

Submicron-structured (Bi0.5Na0.5)0.94Ba0.06TiO3 ceramics, at the Morphotropic Phase Boundary of the solid solution, were prepared from nanometric powder synthesized by sol gel auto-combustion at 500?C. Samples were obtained by hot-pressing (800?C-2h) and subsequent recrystallization at moderate temperature (1050?C-1h) [1]. Accurate resonance measurements at the uncoupled shear mode of thickness-poled plates and their analysis by Alemany software [2] were carried out to obtain electromechanical coupling factors (k15) and piezoelectric (e15, d15) and elastic (sE55)coefficients. Evolution of these as a function of the temperature was determined to study the depolarization process. Results show that irreversible depoling starts from a temperature higher than 120?C. Shear resonance modes are measurable well above the reported depolarization temperature (100?C). A value of d15=105 pC.N-1 was measured at 160?C. This is most probably due to a difuse phase transition from a field-induced ferroelectric (FE) phase to the low temperature non-polar phase at zero field (LTNPZF) phase. The macroscopic ferro-piezoelectricity observed may arise from the coexistence of the FE phase at the nano-scale in the LTNPZF phas

Efecto del campo el?ctrico en la estructura cristalina de cer?micas submicroestructuradas DE (1-X)(Bi0.5Na0.5)TiO3- X BaTiO3 con composici?n pr?xima a la frontera morfotr?pica

--El sistema (1-x)(Bi0.5Na0.5)TiO3 - x BaTiO3 (BNBT100x) presenta una frontera morfotr?pica [1] (MPB) por lo que se presenta como posible material piezoel?ctrico "lead-free". Muy recientemente se han puesto de manifiesto peculiaridades estructurales de este sistema cerca de la MPB. La naturaleza y el rol de ordenamientos at?micos locales diferentes del orden global y la posibilidad de simetr?as inferiores a la rombo?drica son temas de actualidad. Exploramos aqu? el gran potencial de la difracci?n en alta resoluci?n de radiaci?n sincrotr?nica y el ajuste por Rietveld de los difractogramas de alta resoluci?n completos [2], que permite una mejor caracterizaci?n de las fases presentes que en los habituales an?lisis de grupos de picos aislados. Se determina el efecto del campo el?ctrico aplicado en cer?micas submicro- estructuradas [3] de composiciones BNBT4 y BNBT6 obtenidas a partir de precursores nanom?tricos preparados mediante autocombusti?n de sol-gel. Los experimentos de difracci?n se desarrollaron en el sincrotr?n de Stanford (USA) con radiaci?n de 12 keV. Para todas las muestras analizadas se consider? el difractograma completo para un recorrido del vector de dispersi?n Q entre 0 y 6.4?-1. En todos los casos investigados, se esclareci? la ocurrencia de las fases tetragonal P4mm, rombo?drica R3c y/o monocl?nica Cc. Se dan resultados cuantitativos de ocurrencia, concentraciones relativas, forma y tama?o de part?culas y orientaciones preferente

Plasma lipidome and risk of atrial fibrillation: results from the PREDIMED trial

The potential role of the lipidome in atrial fibrillation (AF) development is still widely unknown. We aimed to assess the association between lipidome profiles of the Prevenci\uf3n con Dieta Mediterr\ue1nea (PREDIMED) trial participants and incidence of AF. We conducted a nested case–control study (512 incident centrally adjudicated AF cases and 735 controls matched by age, sex, and center). Baseline plasma lipids were profiled using a Nexera X2 U-HPLC system coupled to an Exactive Plus orbitrap mass spectrometer. We estimated the association between 216 individual lipids and AF using multivariable conditional logistic regression and adjusted the p values for multiple testing. We also examined the joint association of lipid clusters with AF incidence. Hitherto, we estimated the lipidomics network, used machine learning to select important network-clusters and AF-predictive lipid patterns, and summarized the joint association of these lipid patterns weighted scores. Finally, we addressed the possible interaction by the randomized dietary intervention. Forty-one individual lipids were associated with AF at the nominal level (p &lt; 0.05), but no longer after adjustment for multiple-testing. However, the network-based score identified with a robust data-driven lipid network showed a multivariable-adjusted ORper+1SD of 1.32 (95% confidence interval: 1.16–1.51; p &lt; 0.001). The score included PC plasmalogens and PE plasmalogens, palmitoyl-EA, cholesterol, CE 16:0, PC 36:4;O, and TG 53:3. No interaction with the dietary intervention was found. A multilipid score, primarily made up of plasmalogens, was associated with an increased risk of AF. Future studies are needed to get further insights into the lipidome role on AF. Current Controlled Trials number, ISRCTN35739639

Etest® versus broth microdilution for ceftaroline MIC determination with Staphylococcus aureus: results from PREMIUM, a European multicentre study

Objectives: To compare the concordance of ceftaroline MIC values 24 by reference broth microdilution (BMD) and Etest (BioMérieux, France) for MSSA and MRSA isolates, respectively, in isolates from PREMIUM (D372SL00001), a European multi-centre study.  Methods: Ceftaroline MICs were determined by reference BMD and by Etest for 1,242 MSSA and MRSA from adult patients with community-acquired pneumonia or complicated skin and soft tissue infections collected between February and May 2012; tests were performed across six European laboratories. Selected isolates with ceftaroline resistance in broth (MIC >1 mg/L) were retested in three central laboratories to confirm their behaviour.  Results: Overall concordance between BMD and Etest was good, with >97% essential agreement and >95% categorical agreement. Nevertheless, 12 of the 26 MRSA isolates found resistant by BMD scored as susceptible by Etest, with MICs ≤1 mg/L, thus counting as very major errors, whereas only five of 380 MRSA found ceftaroline susceptible in BMD were mis-categorised as resistant by Etest. Twenty-one of the 26 isolates with MICs of 2 mg/L by BMD were then re-tested twice by each of three central laboratories: BMD MICs of 2 mg/L were consistently found for 19 of the 21 isolates. Among 147 Etest results for these 21 isolates (original plus six repeats per isolate) 112 were >1 mg/L.  Conclusions: BMD and Etest have good overall agreement for ceftaroline against Staphylococcus aureus; nevertheless, reliable Etest-based discrimination of the minority of ceftaroline-resistant (MIC 2 mg/L) MRSA is extremely challenging, requiring careful reading of strips, ideally with duplicate testing

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

VARIATIONS IN WEB CONSTRUCTION IN LEUCAUGE VENUSTA (ARANEAE, TETRAGNATHIDAE)

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Reappraisal of post-pancreatectomy hemorrhage (PPH) classifications: do we need to redefine grades A and B?

Background: Post-pancreatectomy hemorrhage (PPH) remains a major complication. The aim of this study was to reappraise the International Study Group of Pancreatic Surgery (ISGPS) classification. Methods: The clinical utility of the ISGPS classification was tested on consecutive pancreatic resections performed at the Pancreas Institute of the University of Verona Hospital. Results: PPH occurred in 65 of the 2429 patients (6.8%) undergoing pancreatic resection. Outcome of patients without PPH and with grade A PPH were comparable in terms of mortality, length of stay, ICU stay and readmission. Patients with grade B late and mild and grade B early and severe PPH had similar hospital stay and mortality rates, but differed in relaparotomy rate (10.1 vs. 81.2%, p < 0.01). Replacing \u201ctime of PPH onset\u201d criterion with post-operative pancreatic fistula (POPF), severe PPH alone, mild PPH/POPF and severe PPH/POPF differed significantly for hospital stay (14 vs. 23 vs. 35 days, p < 0.01) and mortality rate (0 vs. 4 vs. 25%, p = 0.05). Conclusion: Grade A PPH shared the same outcome of patients without PPH. Grade B PPH included two categories of patients with different treatment modalities. The use of \u201cconcomitant POPF\u201d instead of \u201ctime of onset\u201d segregated three discrete categories that differed significantly in terms of clinical outcomes and management

Needs, issues, and expectations on dementia care at home across Europe to inform policy development: Findings from a transnational research study

This qualitative descriptive study explored needs, issues, and expectations on dementia care at home as expressed by relatives of people living with dementia (PwD), health and social care professionals (HSCPs), and members of civil society organisations (CSOs) from four European countries. A focus group methodology integrated with individual semi-structured interviews was adopted to collect data by employing a purposeful sampling method. A total of 13 focus groups and 12 individual interviews were conducted in 2019, involving 65 relatives of PwD, 32 HSCPs, and 23 members of CSOs. Deductive content analysis and findings triangulation were performed to analyse data, and a subgroup of participants confirmed the findings. Relatives need to be (a) informed and trained to cope with changes in PwD, (b) recognised for their caregiving role, and (c) assisted by specialised HSCPs. Professionals who work in partnership with PwD and their relatives call for a reorganisation of available services. CSOs compensate for the lack of proper support, promoting networks, and cooperation with local communities. Several commonalities emerged across countries, highlighting the chance to inform and develop common policies to improve the quality of life of PwD and their relatives across Europe. Policies improving person- and family-centred care and spreading dementia-friendly community concepts and practices are suggested. Strong collaborations between formal and informal services and communities are also needed as well as information on educational strategies to improve the use of resources, promote PwD care, and support PwD relatives\u2019 need

SPIDER DIVERSITY IN COFFEE PLANTATIONS WITH DIFFERENT MANAGEMENT IN SOUTHEAST MEXICO

Volume: 34Start Page: 104End Page: 11