Yttrium Iron Garnet/Barium Titanate Multiferroic Composites

Dense multiferroic 0-3 type composites encompassing BaTiO3 and Y3Fe5O12 were fabricated by the solid state reaction method. X-ray diffraction data combined with Scanning Electron Microscopy imaging show virtual immiscibility between the two phases, with the Y3Fe5O12 ferrimagnetic phase well dispersed in the tetragonal BaTiO3 ferroelectric matrix. Raman spectroscopy analyses corroborate the polar nature of the BaTiO3 matrix in composites with a Y3Fe5O12 content as great as 40 wt%. Ferrimagnetism is detected in all composites and no additional magnetic phases are distinguished. Although these dense ceramics can be electrically poled, they exhibit a very weak magnetoelectric response, which slightly increases with Y3Fe5O12 content

Proline cis-​trans isomerization and its implications for the dimerization of analogues of cyclopeptide stylostatin 1: a combined computational and experimental study

Cis and trans proline conformers are often associated with dramatic changes in the biological function of peptides. A slow equilibrium between cis and trans Ile-Pro amide bond conformers occurs in constrained derivatives of the native marine cyclic heptapeptide stylostatin 1 (cyclo-(NSLAIPF)), a potential anticancer agent. In this work, four cyclopeptides, cyclo-(NSTAIPF), cyclo-(KSTAIPF), cyclo-(RSTAIPF) and cyclo-(DSTAIPF), which are structurally related to stylostatin 1, are experimentally and computationally examined in order to assess the effect of residue mutations on the cis-trans conformational ratio and the apparent capacity to form dimeric aggregates. Primarily, cyclo-(KSTAIPF) and cyclo-(RSTAIPF) showed specific trends in circular dichroism, MALDI-TOF and HPLC purification experiments, which suggests the occurrence of peptide dimerization. Meanwhile, the NMR spectrum of cyclo-(KSTAIPF) indicates that this cyclopeptide exists in the two slow-exchange families of conformations mentioned above. Molecular dynamics simulations combined with quantum mechanical calculations have shed light on the factors governing the cis/trans conformational ratio. In particular, we have found that residue mutations affect the internal hydrogen bond pattern which ultimately tunes the cis/trans conformational ratio and that only trans conformers are capable of aggregating due to the shape complementarity of the two subunits

What two models may teach us about duality violations in QCD

Though the operator product expansion is applicable in the calculation of current correlation functions in the Euclidean region, when approaching the Minkowskian domain, violations of quark-hadron duality are expected to occur, due to the presence of bound-state or resonance poles. In QCD finite-energy sum rules, contour integrals in the complex energy plane down to the Minkowskian axis have to be performed, and thus the question arises what the impact of duality violations may be. The structure and possible relevance of duality violations is investigated on the basis of two models: the Coulomb system and a model for light-quark correlators which has already been studied previously. As might yet be naively expected, duality violations are in some sense "maximal" for zero-width bound states and they become weaker for broader resonances whose poles lie further away from the physical axis. Furthermore, to a certain extent, they can be suppressed by choosing appropriate weight functions in the finite-energy sum rules. A simplified Ansatz for including effects of duality violations in phenomenological QCD sum rule analyses is discussed as well.Comment: 17 pages, 6 figures; version to appear in JHE

Do centenarians die healthier than younger elders? A comparative epidemiological study in Spain

This study aims to describe the clinical course, drug use, and health services use characteristics during the last year of life of elders who die being centenarians and to identify key aspects differentiating them from elders who die at an earlier age, with a particular focus on sex differences. We conducted an observational, population-based study in the EpiChron Cohort (Aragon, Spain). The population was stratified by sex and into three age sub-populations (80-89, 90-99, and >= 100 years), and their characteristics were described and compared. Multimorbidity was the rule in our elders, affecting up to 3 in 4 centenarians and 9 in 10 octogenarians and nonagenarians. Polypharmacy was also observed in half of the centenarian population and in most of the younger elders. Risk factors for cardiovascular disease (i.e., hypertension, dyslipidaemia, diabetes), cerebrovascular disease and dementia were amongst the most common chronic conditions in all age groups, whereas the gastroprotective drugs and antithrombotic agents were the most dispensed drugs. Centenarians presented in general lower morbidity and treatment burden and lower use of both primary and hospital healthcare services than octogenarians and nonagenarians, suggesting a better health status. Sex-differences in their clinical characteristics were more striking in octogenarians and tended to decrease with age

LFI 30 and 44 GHz receivers Back-End Modules

The 30 and 44 GHz Back End Modules (BEM) for the Planck Low Frequency Instrument are broadband receivers (20% relative bandwidth) working at room temperature. The signals coming from the Front End Module are amplified, band pass filtered and finally converted to DC by a detector diode. Each receiver has two identical branches following the differential scheme of the Planck radiometers. The BEM design is based on MMIC Low Noise Amplifiers using GaAs P-HEMT devices, microstrip filters and Schottky diode detectors. Their manufacturing development has included elegant breadboard prototypes and finally qualification and flight model units. Electrical, mechanical and environmental tests were carried out for the characterization and verification of the manufactured BEMs. A description of the 30 and 44 GHz Back End Modules of Planck-LFI radiometers is given, with details of the tests done to determine their electrical and environmental performances. The electrical performances of the 30 and 44 GHz Back End Modules: frequency response, effective bandwidth, equivalent noise temperature, 1/f noise and linearity are presented

Study of the temperature dependence of the giant electric field-induced strain in Nb-doped BNT-BT-BKT piezoceramics

Dense Bi0.487Na0.427K0.06Ba0.026TiO3 (BNKBT) and Nb-doped Bi0.487Na0.427K0.06Ba0.026Ti0.98Nb0.02O3 (Nb-BNKBT) ceramics were prepared by the solid state reaction route. BNKBT is a non-ergodic relaxor and exhibits a piezoelectric response typical for a ferroelectric, whereas Nb-BNKBT is an ergodic relaxor and exhibits an electromechanical response typical for an incipient ferroelectric. The incorporation of 2 mol% of Nb into the BNKBT lattice is accompanied by an enhancement of the room-temperature unipolar field-induced strain from 0.19% to 0.43% at 75 kV/cm. BNKBT shows a depolarisation temperature of 90C, above which an electrostrictive response is observed, whereas Nb-BNKBT shows an electrostrictive response in the entire temperature range studied. At 40 kV/cm, Nb-BNKBT exhibits a temperature stable electromechanical response in comparison with undoped BNKBT, but it worsens under higher electric fields. These results may motivate further investigations on the impact of minor doping and driving electric fields on the electromechanical response of Bi0.5Na0.5TiO3–Bi0.5K0.5TiO3–BaTiO3-based ceramics

Ventricular arrhythmias in patients with functional mitral regurgitation and implantable cardiac devices: implications of mitral valve repair with Mitraclip

Background: Limited information has been reported regarding the impact of percutaneous mitral valve repair (PMVR) on ventricular arrhythmic (VA) burden. The aim of this study was to address the incidence of VA and appropriate antitachycardia implantable cardiac defibrillator (ICD) therapies before and after PMVR. Methods: We retrospectively analyzed all consecutive patients with heart failure with reduce left ventricular ejection fraction (LVEF), functional mitral regurgitation (FMR) grade 3+ or 4+ and an active ICD or cardiac resynchronizer who underwent PMVR in any of the eleven recruiting centers. Only patients with complete available device VA monitoring from one-year before to one year after PMVR were included. Baseline clinical and echocardiographic characteristics were collected before PMVR and at 12-months follow-up. Results: Ninety-three patients (68.2+/-10.9 years old, male 88.2%) were enrolled. PMVR was successfully performed in all patients and device success at discharge was 91.4%. At 12-month follow-up, we observed a significant reduction in mitral regurgitation severity, NT-proBNP and prevalence of severe pulmonary hypertension and severe kidney disease. Patients also referred a significant improvement in NYHA functional class and showed a non-significant trend to reserve left ventricular remodeling. After PMVR a significant decrease in the incidence of non-sustained ventricular tachycardia (VT) (5.0+/-17.8 vs. 2.7+/-13.5, P=0.002), sustained VT or ventricular fibrillation (0.9+/-2.5 vs. 0.5+/-2.9, P=0.012) and ICD antitachycardia therapies (2.5+/-12.0 vs. 0.9+/-5.0, P=0.033) were observed. Conclusions: PMVR was related to a reduction in arrhythmic burden and ICD therapies in our cohort

Transcranial Magnetic Stimulation Provides Means to Assess Cortical Plasticity and Excitability in Humans with Fragile X Syndrome and Autism Spectrum Disorder

Fragile X Syndrome (FXS) is the most common heritable cause of intellectual disability. In vitro electrophysiologic data from mouse models of FXS suggest that loss of fragile X mental retardation protein affects intracortical excitability and synaptic plasticity. Specifically, the cortex appears hyperexcitable, and use-dependent long-term potentiation (LTP) and long-term depression (LTD) of synaptic strength are abnormal. Though animal models provide important information, FXS and other neurodevelopmental disorders are human diseases and as such translational research to evaluate cortical excitability and plasticity must be applied in the human. Transcranial magnetic stimulation paradigms have recently been developed to non-invasively investigate cortical excitability using paired pulse stimulation, as well as LTP- and LTD-like synaptic plasticity in response to theta burst stimulation (TBS) in vivo in the human. TBS applied on consecutive days can be used to measure metaplasticity (the ability of the synapse to undergo a second plastic change following a recent induction of plasticity). The current study investigated intracortical inhibition, plasticity and metaplasticity in full mutation females with FXS, participants with autism spectrum disorders (ASD), and neurotypical controls. Results suggest that intracortical inhibition is normal in participants with FXS, while plasticity and metaplasticity appear abnormal. ASD participants showed abnormalities in plasticity and metaplasticity, as well as heterogeneity in intracortical inhibition. Our findings highlight the utility of non-invasive neurophysiological measures to translate insights from animal models to humans with neurodevelopmental disorders, and thus provide direct confirmation of cortical dysfunction in patients with FXS and ASD

Adherence to chronic medication in older populations: application of a common protocol among three European cohorts

Purpose: The purpose of this study was to evaluate and compare medication adherence to chronic therapies in older populations across different regions in Europe. Methods: This explorative study applied a harmonized method of data extraction and analysis from pharmacy claims databases of three European countries to compare medication adherence at a cross-country level. Data were obtained for the period between January 1, 2010, and December 31, 2011. Patients (aged >= 65 years) who newly initiated to oral antidiabetics, antihyperlipidemics, or antiosteoporotics were identified and followed for over a 12-month period. Main outcome measures were medication adherence (medication possession ratio, [MPR]; implementation) and persistence on index treatment. All country-specific data sets were prepared by employing a common data input model. Outcome measures were calculated for each country and pooled using random effect models. Results: In total, 39, 186 new users were analyzed. In pooled data from the three countries, suboptimal implementation (MPR <80%) was 52.45% (95% CI: 33.43-70.79) for antihyperlipidemics, 61.35% (95% CI: 52.83-69.22) for antiosteoporotics, and 30.33% (95% CI: 25.53-35.60) for oral antidiabetics. Similarly, rates of non-persistence (discontinuation) were 55.63% (95% CI: 35.24-74.29) for antihyperlipidemics, 60.24% (95% CI: 45.35-73.46) for antiosteoporotics, and 46.80% (95% CI: 36.40-57.4) for oral antidiabetics. Conclusion: Medication adherence was suboptimal with >50% of older people non-adherent to antihyperlipidemics and antiosteoporotics in the three European cohorts. However, the degree of variability in adherence rates among the three countries was high. A harmonized method of data extraction and analysis across health-related database in Europe is useful to compare medication-taking behavior at a cross-country level