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Deals with a study which examined the microstructure of iron-neodymium-boron based real sintered magnets. Measurement of the magnetic properties of the alloy; Preconditions of the intermettalic phase; Solidification of the liquid phase.

Abstract: The insulation resistance (IR) and the electrical endurance of Y-acceptor doped (Ba,Ca)(Ti,Zr)O3 ceramics, fired in reducing atmospheres, are significantly improved by a re-oxidation treatment. This effect has been studied by means of impedance spectroscopy (IS). Insulating grain boundary barrier layers were detected also without interaction with Ni-inner electrodes, as they are applied in multilayer ceramic capacitors (MLCCs). In moist firing atmospheres H2O vapor was found to react with oxygen vacancies, forming positively charged hydroxyl defects on regular oxygen sites in the crystal lattice. Hopping of protonic defects is supposed to raise the ionic conductivity. Re-oxidation in dry gas mixtures of O2 and N2, however, desorbs water from the dielectric material and improves the IR. DC-field stress heavily degrades the grain boundary barriers. Protons in the dielectric material largely accelerate the electrical degradation. Hydroxyl defects are also considered to be responsible for alterations of the dielectric temperature characteristics at the Curie point. [Copyright &y& Elsevier]

Monodisperse and nanocrystalline BaTiO3 powders of different stoichiometries were synthesized through the hydrolytic decomposition of mixed metal alkoxide solutions with water-in-oil microemulsions as reaction media. The method allows a tailor-made preparation of powder particles as small as 10 nm in average. Characterization with respect to purity, morphology, and behavior upon annealing was conducted in order to determine appropriate processing conditions for the preparation of pure, dense nanocrystalline ceramics. As a result, ceramics with a mean grain size as small as 35 nm were achieved. Raman spectroscopy revealed for the first time local tetragonality in pure nanocrystalline bulk BaTiO3-ceramics with such a fine microstructure. [ABSTRACT FROM AUTHOR]

The electrical conductivity of donor-doped BaTiO 3 thermistor ceramics with excessive BaO revealing a reduction-persistent PTCR effect has been carefully examined depending on materials' composition and oxygen partial pressure at moderate temperatures between 973 and 1273 K. This thermal regime represents the range which is relevant for the realization of insulating grain boundaries in these electrically inhomogeneous ceramic materials through reoxidation. Based on the experimental results strong evidence for a general correlation between the PTCR characteristics, DC-conductivity and the herewith associated defect chemistry significant to thermistor applications is presented for the system (Ba, La) m TiO 3 , where m designates the BaO-excess (m≥ 1). Nominal compositions with a relatively low (Ba + La)/Ti ratio m only show a rather poor PTCR effect and an overall donor-type response in conductivity can be observed at all levels of oxygen partial pressure considered in the present study. With increasing (Ba + La)/Ti ratio m the nonlinear resistivity jump with increasing temperature strongly improves and the acceptor-type behaviour seems to dominate the total conductivity at partial pressures of oxygen above approximately 10 -6 MPa. This result for compositions with high BaO-excess can be understood by the local formation of point defect associates in the grain boundary regions that consist of both acceptor-type titanium vacancies and donor-type oxygen vacancies. Their origin is attributed to the preferential local incorporation of excessive BaO into the BaTiO 3 lattice at the intergranular interfaces.

Autologous transplantation continues to be the cornerstone of younger and fit multiple myeloma patients. It is known that frontline induction therapy before transplantation can influence post-transplant results. Therefore, best frontline treatment for transplant-eligible patients should be based on best available evidence to guide therapy. Furthermore, until now due to data scarcity, it was not possible to thoroughly compare lenalidomide to other regimens in this setting. We performed a systematic review and network (mixed treatment comparison) meta-analysis of 21 clinical trial publications, enrolling 6474 patients and comparing 11 different treatment frontline setting regimens regarding survival, response, and safety outcomes. OS analysis showed superiority of CRD (cyclophosphamide-lenalidomide-dexamethasone) over TD-based (thalidomide-dexamethasone, HR = 0.76,0.62-0.90), VAD-based (HR = 0.71,0.52-0.90), and Z-Dex (idarubicin-dexamethasone, HR = 0.37,0.17-0.76) regimens. Concerning PFS, VTD (bortezomib-thalidomide-dexametasone) showed superior results when compared with TD-based (HR = 0.66,0.51-0.84), VAD-based (HR = 0.61,0.46-0.82), Z-Dex (HR = 0.42,0.22-0.78), and high dose dexamethasone (Dex, HR = 0.62,0.41-0.90) regimens. Bortezomib/thalidomide regimens were not superior to lenalidomide, considering these outcomes. Also, concerning complete and overall response, VTD ranked first among other regimens, showing clear superiority over thalidomide-only containing protocols. Safety outcome evaluated infectious, cardiac, gastrointestinal, neurological, thrombotic, and hematological grade 3 to 4 adverse events. Risk of thrombotic events was higher with TAD (thalidomide-doxorubicin-dexamethasone), neurological with PAD (bortezomib-doxorubicin-dexamethasone), infectious with Dex, hematological with Z-Dex, gastrointestinal with VTD, and cardiac with PAD regimens. Our study endorses current recommendations on combined immunomodulatory drugs and proteasome inhibitors frontline regimens (in triplets) in transplant-eligible multiple myeloma patients, but also formally demonstrates the favorable performance of lenalidomide in overall and progression-free survival, when compared with bortezomib/thalidomide protocols., (© 2018 John Wiley & Sons, Ltd.)

Background: Although redefinition for acute myocardial infarction (AMI) has been proposed few years ago, to date it has not been universally adopted by many institutions. The purpose of this study is to evaluate the diagnostic, prognostic and economical impact of the new diagnostic criteria for AMI., Methods: Patients consecutively admitted to the emergency department with suspected acute coronary syndromes were enrolled in this study. Troponin T (cTnT) was measured in samples collected for routine CK-MB analyses and results were not available to physicians. Patients without AMI by traditional criteria and cTnT > or = 0.035 ng/mL were coded as redefined AMI. Clinical outcomes were hospital death, major cardiac events and revascularization procedures. In-hospital management and reimbursement rates were also analyzed., Results: Among 363 patients, 59 (16%) patients had AMI by conventional criteria, whereas additional 75 (21%) had redefined AMI, an increase of 127% in the incidence. Patients with redefined AMI were significantly older, more frequently male, with atypical chest pain and more risk factors. In multivariate analysis, redefined AMI was associated with 3.1 fold higher hospital death (95% CI: 0.6-14) and a 5.6 fold more cardiac events (95% CI: 2.1-15) compared to those without AMI. From hospital perspective, based on DRGs payment system, adoption of AMI redefinition would increase 12% the reimbursement rate [3552 Int dollars per 100 patients evaluated]., Conclusions: The redefined criteria result in a substantial increase in AMI cases, and allow identification of high-risk patients. Efforts should be made to reinforce the adoption of AMI redefinition, which may result in more qualified and efficient management of ACS.

NaNbO(3) powders with various particle sizes (ranging from 30 nm to several microns) and well-controlled stoichiometry were obtained through microemulsion-mediated synthesis. The effect of particle size on the phase transformation of the prepared NaNbO(3) powders was studied using X-ray powder diffraction, Raman spectroscopy, and nuclear site group analysis based on these spectroscopic data. Coarsened particles exhibit an orthorhombic Pbcm (D(2h)(11), no. 57) structure corresponding to the bulk structure, as observed for single crystals or powders prepared by conventional solid-state reaction. The crystal symmetry of submicron powders was refined with the space group Pmc2(1) (C(2v)(2), no. 26). The reduced perovskite cell volumes of these submicron powders were most expanded compared to all the other structures. Fine particles with a diameter of less than 70 nm as measured from SEM observations showed an orthorhombic Pmma (D(2h)(5), no. 51) crystal symmetry. The perovskite formula cell of this structure was pseudocubic and was the most compact one. A possible mechanism of the phase transformation is suggested.

Although several advances have been made in the management of acute coronary syndromes, the adoption of such measures in clinical practice has been suboptimal. The implementation of critical pathways has been suggested as a strategy to improve clinical effectiveness, although its effect is still to be demonstrated. The objective was to evaluate the impact of a critical pathway on the process of care of patients admitted with acute coronary syndromes in a teaching hospital. In a prospective cohort study, patients 30 years or older admitted to the emergency department with suspected acute coronary syndromes were evaluated. Primary outcomes were major cardiovascular events, percutaneous coronary intervention, and in-hospital mortality during 1 semester before and 4 semesters after implementation of the pathway. Multivariate logistic regression analysis was used to adjust for differences between the periods studied and to identify predictors of poor prognosis. Of the 1003 patients evaluated, 150 (15%) had myocardial infarction, and 240 (24%) had unstable angina. There was no difference in clinical characteristics and risk assessment in the periods evaluated. Overall, the quality of care improved after the pathway, with a significant decrease in complication and mortality rates in the last 2 years. In multivariate analysis, patients admitted in the last semester showed fewer major cardiovascular events (odds ratio = 0.74; P = 0.02) and more percutaneous coronary intervention (odds ratio = 1.3; P = 0.03). The implementation of a critical pathway may have a positive impact on the quality of care of patients with acute coronary syndromes. Further studies are needed to evaluate better this and other initiatives aimed at maximizing clinical effectiveness.