A 2D ferroelectric vortex pattern in twisted BaTiO3 freestanding layers.

The wealth of complex polar topologies1-10 recently found in nanoscale ferroelectrics results from a delicate balance between the intrinsic tendency of the materials to develop a homogeneous polarization and the electric and mechanical boundary conditions imposed on them. Ferroelectric-dielectric interfaces are model systems in which polarization curling originates from open circuit-like electric boundary conditions, to avoid the build-up of polarization charges through the formation of flux-closure11-14 domains that evolve into vortex-like structures at the nanoscale15-17 level. Although ferroelectricity is known to couple strongly with strain (both homogeneous18 and inhomogeneous19,20), the effect of mechanical constraints21 on thin-film nanoscale ferroelectrics has been comparatively less explored because of the relative paucity of strain patterns that can be implemented experimentally. Here we show that the stacking of freestanding ferroelectric perovskite layers with controlled twist angles provides an opportunity to tailor these topological nanostructures in a way determined by the lateral strain modulation associated with the twisting. Furthermore, we find that a peculiar pattern of polarization vortices and antivortices emerges from the flexoelectric coupling of polarization to strain gradients. This finding provides opportunities to create two-dimensional high-density vortex crystals that would enable us to explore previously unknown physical effects and functionalities.

Validation of the aberrant salience inventory in a general and clinical Spanish population.

BACKGROUND: The concept of aberrant salience is related to the onset of psychosis. Its study is important for early identification and possible intervention in processes activating later positive symptoms. OBJECTIVES: This study validated the Spanish Aberrant Salience Inventory (ASI) for adult and clinical populations. METHODS: The sample consisted of 6178 participants, of whom 4523 were adolescents, 1292 were general population adults and 363 were patients with a psychopathology. RESULTS: The evidence provided validates the instrument's structure. Invariance of measurement suggests that both men and women, patients and nonclinical population (adults and adolescents) interpreted the items on the ASI similarly. The distribution of scores by age also suggests stabilization of the trend at about 19 years of age, showing a developmental change in motivational response. The hypothesis that patients, and in particular, those diagnosed with schizophrenia and other psychotic disorders and bipolar disorders would have the highest average scores in aberrant salience was met. CONCLUSIONS: This is a valuable instrument for evaluating a complex process related to abnormal motivation in the development of schizophrenia.

Incubation period of COVID-19: A systematic review and meta-analysis. / Período de incubación de la COVID-19: revisión sistemática y metaanálisis.

BACKGROUND AND OBJECTIVE: The incubation period of COVID-19 helps to determine the optimal duration of the quarantine and inform predictive models of incidence curves. Several emerging studies have produced varying results; this systematic review aims to provide a more accurate estimate of the incubation period of COVID-19. METHODS: For this systematic review, a literature search was conducted using Pubmed, Scopus/EMBASE, and the Cochrane Library databases, covering all observational and experimental studies reporting the incubation period and published from 1 January 2020 to 21 March 2020.We estimated the mean and 95th percentile of the incubation period using meta-analysis, taking into account between-study heterogeneity, and the analysis with moderator variables. RESULTS: We included seven studies (n = 792) in the meta-analysis. The heterogeneity (I2 83.0%, p < 0.001) was significantly decreased when we included the study quality and the statistical model used as moderator variables (I2 15%). The mean incubation period ranged from 5.6 (95% CI: 5.2 to 6.0) to 6.7 days (95% CI: 6.0 to 7.4) according to the statistical model. The 95th percentile was 12.5 days when the mean age of patients was 60 years, increasing 1 day for every 10 years. CONCLUSION: Based on the published data reporting the incubation period of COVID-19, the mean time between exposure and onset of clinical symptoms depended on the statistical model used, and the 95th percentile depended on the mean age of the patients. It is advisable to record sex and age when collecting data in order to analyze possible differential patterns.

Controlled Sign Reversal of Electroresistance in Oxide Tunnel Junctions by Electrochemical-Ferroelectric Coupling.

The persistence of ferroelectricity in ultrathin layers relies critically on screening or compensation of polarization charges which otherwise destabilize the ferroelectric state. At surfaces, charged defects play a crucial role in the screening mechanism triggering novel mixed electrochemical-ferroelectric states. At interfaces, however, the coupling between ferroelectric and electrochemical states has remained unexplored. Here, we make use of the dynamic formation of the oxygen vacancy profile in the nanometer-thick barrier of a ferroelectric tunnel junction to demonstrate the interplay between electrochemical and ferroelectric degrees of freedom at an oxide interface. We fabricate ferroelectric tunnel junctions with a La_{0.7}Sr_{0.3}MnO_{3} bottom electrode and BaTiO_{3} ferroelectric barrier. We use poling strategies to promote the generation and transport of oxygen vacancies at the metallic top electrode. Generated oxygen vacancies control the stability of the ferroelectric polarization and modify its coercive fields. The ferroelectric polarization, in turn, controls the ionization of oxygen vacancies well above the limits of thermodynamic equilibrium, triggering the build up of a Schottky barrier at the interface which can be turned on and off with ferroelectric switching. This interplay between electronic and electrochemical degrees of freedom yields very large values of the electroresistance (more than 10^{6}% at low temperatures) and enables a controlled switching between clockwise and counterclockwise switching modes in the same junction (and consequently, a change of the sign of the electroresistance). The strong coupling found between electrochemical and electronic degrees of freedom sheds light on the growing debate between resistive and ferroelectric switching in ferroelectric tunnel junctions, and moreover, can be the source of novel concepts in memory devices and neuromorphic computing.

Oxygen intercalation in PVD graphene grown on copper substrates: A decoupling approach.

We investigate the intercalation process of oxygen in-between a PVD-grown graphene layer and different copper substrates as a methodology for reducing the substrate-layer interaction. This growth method leads to an extended defect-free graphene layer that strongly couples with the substrate. We have found, by means of X-ray photoelectron spectroscopy, that after oxygen exposure at different temperatures, ranging from 280 °C to 550 °C, oxygen intercalates at the interface of graphene grown on Cu foil at an optimal temperature of 500 °C. The low energy electron diffraction technique confirms the adsorption of an atomic oxygen adlayer on top of the Cu surface and below graphene after oxygen exposure at elevated temperature, but no oxidation of the substrate is induced. The emergence of the 2D Raman peak, quenched by the large interaction with the substrate, reveals that the intercalation process induces a structural undoing. As suggested by atomic force microscopy, the oxygen intercalation does not change significantly the surface morphology. Moreover, theoretical simulations provide further insights into the electronic and structural undoing process. This protocol opens the door to an efficient methodology to weaken the graphene-substrate interaction for a more efficient transfer to arbitrary surfaces.

[Exploring Early Maladaptative Schema (EMS) in adults with bipolar disorder: A systematic review of the scientific literature]. / L'exploration des Schémas Précoces Inadaptés (SPI) chez les personnes adultes atteintes de troubles bipolaires: une revue systématique de la littérature scientifique.

OBJECTIVES: Clinical heterogeneity during euthymic states is a crucial issue in bipolar disorders. Indeed, actual data are not sufficient to understand why some patients are unharmed by subthreshold symptoms and have functional impairments whereas others have a functional remission but have subthreshold symptoms. Based on the Ball model, cognitive and schematic vulnerability interact with genetic vulnerability and trigger affective symptoms with the intervention of stressful life events. Furthermore, according to this model, adjustment and adaptation to illness assessed by functional outcome and illness experience are associated with this cognitive and schematic vulnerability. So, theoretical arguments support that childhood adversity and temperamental deregulation characterize patients with bipolar disorders. Thus, the aim of this study is to systematically review studies of Early Maladaptive Schemas in bipolar disorder, to determine whether Early Maladaptive Schemas have specificity in bipolar disorder in comparison with other populations, and to identify which Early Maladaptive Schemas could be activated. The challenge of this review is to identify if the taking of early maladaptive schemas into account could allow us to better identify, understand and manage bipolar disorders. METHODS: This systematic review was led according to the Preferred Reporting Items for Systematic review and Meta-Analysis statement on the electronic databases Cochrane, PsycArticles, Psychology and Behavioral Sciences Collection, PsycInfo, PubMed, ScienceDirect and Scopus with « early maladaptive schemas ¼ AND « bipolar disorder ¼ as keywords. Only studies meeting eligibility criteria concerning publication status, language, population and outcomes were included after several screenings on basis of title, abstract and full-text. Then, we carried out data extraction in accordance with criteria defined in principle (about characteristics of participants, objectives, materiel and methods, principle results and bias). RESULTS: Among 39 records identified, a total of 10 studies met eligibility criteria for inclusion in this review. Synthesizing findings across the studies revealed three important topics. First, early maladaptive schemas appear as potential cognitive characteristics that clinicians have to investigate in clinical practice. Indeed, patients with bipolar disorders present greater activation of the early maladaptive schemas in comparison with people who have no disorder. This point supports the first part of Ball's theoretical model that considers schemas as a vulnerability to bipolarity. Secondly, early maladaptive schemas are relevant to distinguish bipolar disorders from unipolar depression and borderline personality disorder. A greater and a lower activation are respectively identified among bipolar disorders. Thirdly, supporting the second part of Ball's model, early maladaptive schemas play a key role in recovery regarding their impact on the course of bipolarity, in particular on suicidality and functional impairment. Finally, these dysfunctional schemas allow us to understand the clinical heterogeneity of bipolar disorder, and among others, about the type of bipolarity. These results have several implications, but there are some limits in this systematic review. First, no French study has been done. Then, reduced sample sizes in these studies increased the risk to conclude wrongly to an activation difference between groups. Furthermore, probably due to the variety of methods and populations, we could not identify an homogeneous pattern of early activated maladaptive schemas. Overall, scientific approaches used in these studies are based on statistical models using mean and standard deviation. These types of statistical analyses are the main limit because they cannot represent the heterogeneity of early maladaptive schemas profiles. CONCLUSIONS: Schema theory proves to be a relevant approach in bipolar disorders, and early maladaptive schemas appear to be important to take into account in clinical practice. Nevertheless, in order to propose schemas therapy appropriately, it is necessary to specify if early maladaptive schemas are activated and to specify therapeutic indications because of clinical heterogeneity. Moreover, data do not yet allow us to understand the disparity of profiles during the inter-episode period. Indeed, a French research perspective is being considered that will prefer a person-oriented approach.

High-quality PVD graphene growth by fullerene decomposition on Cu foils.

We present a new protocol to grow large-area, high-quality single-layer graphene on Cu foils at relatively low temperatures. We use C60 molecules evaporated in ultra high vacuum conditions as carbon source. This clean environment results in a strong reduction of oxygen-containing groups as depicted by X-ray photoelectron spectroscopy (XPS). Unzipping of C60 is thermally promoted by annealing the substrate at 800ºC during evaporation. The graphene layer extends over areas larger than the Cu crystallite size, although it is changing its orientation with respect to the surface in the wrinkles and grain boundaries, producing a modulated ring in the low energy electron diffraction (LEED) pattern. This protocol is a self-limiting process leading exclusively to one single graphene layer. Raman spectroscopy confirms the high quality of the grown graphene. This layer exhibits an unperturbed Dirac-cone with a clear n-doping of 0.77 eV, which is caused by the interaction between graphene and substrate. Density functional theory (DFT) calculations show that this interaction can be induced by a coupling between graphene and substrate at specific points of the structure leading to a local sp3 configuration, which also contribute to the D-band in the Raman spectra.

Proximity Driven Commensurate Pinning in YBa2Cu3O7 through All-Oxide Magnetic Nanostructures.

The design of artificial vortex pinning landscapes is a major goal toward large scale applications of cuprate superconductors. Although disordered nanometric inclusions have shown to modify their vortex phase diagram and to produce enhancements of the critical current ( MacManus-Driscoll , J. L. ; Foltyn , S. R. ; Jia , Q. X. ; Wang , H. ; Serquis , A. ; Civale , L. ; Maiorov , B. ; Hawley , M. E. ; Maley , M. P. ; Peterson , D. E. Nat. Mater. 2004 , 3 , 439 - 443 and Yamada , Y. ; Takahashi , K. ; Kobayashi , H. ; Konishi , M. ; Watanabe , T. ; Ibi , A. ; Muroga , T. ; Miyata , S. ; Kato , T. ; Hirayama , T. ; Shiohara , Y. Appl. Phys. Lett. 2005 , 87 , 1 - 3 ), the effect of ordered oxide nanostructures remains essentially unexplored. This is due to the very small nanostructure size imposed by the short coherence length, and to the technological difficulties in the nanofabrication process. Yet, the novel phenomena occurring at oxide interfaces open a wide spectrum of technological opportunities to interplay with the superconductivity in cuprates. Here, we show that the unusual long-range suppression of the superconductivity occurring at the interface between manganites and cuprates affects vortex nucleation and provides a novel vortex pinning mechanism. In particular, we show evidence of commensurate pinning in YBCO films with ordered arrays of LCMO ferromagnetic nanodots. Vortex pinning results from the proximity induced reduction of the condensation energy at the vicinity of the magnetic nanodots, and yields an enhanced friction between the nanodot array and the moving vortex lattice in the liquid phase. This result shows that all-oxide ordered nanostructures constitute a powerful, new route for the artificial manipulation of vortex matter in cuprates.

Effectiveness of influenza vaccination programme in preventing hospital admissions, Valencia, 2014/15 early results.

Preliminary results for the 2014/15 season indicate low to null effect of vaccination against influenza A(H3N2)-related disease. As of week 5 2015, there have been 1,136 hospital admissions, 210 were due to influenza and 98% of subtype A strains were H3. Adjusted influenza vaccine effectiveness was 33% (range: 6-53%) overall and 40% (range: 13% to 59%) in those 65 years and older. Vaccination reduced by 44% (28-68%) the probability of admission with influenza.

Effect of switch from flash glucose monitoring to flash glucose monitoring with real-time alarms on hypoglycaemia in people with type 1 diabetes mellitus.

We aimed to evaluate the utility of the FreeStyle Libre 2 device for reducing time below range level 1 and level 2 compared with the Freestyle Libre device (without alarms) in people with type 1 diabetes mellitus. We conducted longitudinal observational follow-up study of a cohort of 100 people with type 1 diabetes mellitus who had switched from FreeStyle Libre to FreeStyle Libre 2 as part of routine clinical practice. Three months after switching to FreeStyle Libre 2, compared with results with FreeStyle Libre, there were a significant improvements in time below range level 1 (p = 0.02) and level 2 (p <0.001), time in range (p <0.001), time above range level 1 (p = 0.002), glucose management indicator (p= 0.04) and mean glucose (p= 0.04) during follow-up. Furthermore there was a significant direct association between age and change in TIR with a coefficient of 0.23, and a significant inverse association between age and change in TAR-1 with a coefficient of 0.11. Switching to a flash glucose monitoring system with alarms improves time below range, time in range and coefficient of variation in people with type 1 diabetes mellitus.

[Factors associated with dissatisfaction with pharmacological treatment in patients with type 2 diabetes mellitus: A cross-sectional study]. / Factores asociados a la insatisfacción con el tratamiento farmacológico en pacientes con diabetes mellitus tipo 2: estudio transversal.

BACKGROUND AND OBJECTIVES: Diabetes is a chronic disease with a high impact on both health and Quality of Life Related to Health (QLRH). To evaluate the satisfaction of treatment in patients with type 2 diabetes mellitus through the Diabetes Treatment Satisfaction Questionnaire (DTSQ) and its relationship with sociodemographic variables, with antidiabetic medication and clinical-analytical variables. MATERIALS AND METHODS: This cross-sectional study was conducted in General University Hospital of San Juan de Alicante between September 2016 and December 2017. Two hundred thirty-two patients diagnosed with type 2 diabetes mellitus at least 1 year before inclusion, treated with antidiabetic medication were included. The Spanish version of the DTSQ scale was used to measure satisfaction with treatment. Factors associated with low satisfaction were analyzed by applying the Chi-square test for qualitative variables and Student-T for quantitative variables. To estimate magnitudes of association, logistic models were adjusted. RESULTS: Two hundred thirty-two patients were included in this study. 21.5% of the patients presented low satisfaction with the treatment. Patients who presented low satisfaction with treatment were associated with medications that could cause hypoglycemia (OR: 2.872 [1.195-6.903]), HbA1c levels higher than 7% (OR: 2.260 [1.005-5.083]) and drugs administered by the route oral (OR: 2.749 [1.233-6.131]). CONCLUSIONS: Patients with type 2 diabetes mellitus who had a lower score on the DTSQ questionnaire were associated with medications that produced hypoglycaemia, and with higher levels of HbA1c higher than 7%, and those who took oral medication.

Epidemiology of ataxia and hereditary spastic paraplegia in Spain: A cross-sectional study.

INTRODUCTION: Ataxia and hereditary spastic paraplegia are rare neurodegenerative syndromes. We aimed to determine the prevalence of these disorders in Spain in 2019. PATIENTS AND METHODS: We conducted a cross-sectional, multicentre, retrospective, descriptive study of patients with ataxia and hereditary spastic paraplegia in Spain between March 2018 and December 2019. RESULTS: We gathered data from a total of 1933 patients from 11 autonomous communities, provided by 47 neurologists or geneticists. Mean (SD) age in our sample was 53.64 (20.51) years; 938 patients were men (48.5%) and 995 were women (51.5%). The genetic defect was unidentified in 920 patients (47.6%). A total of 1371 patients (70.9%) had ataxia and 562 (29.1%) had hereditary spastic paraplegia. Prevalence rates for ataxia and hereditary spastic paraplegia were estimated at 5.48 and 2.24 cases per 100 000 population, respectively. The most frequent type of dominant ataxia in our sample was SCA3, and the most frequent recessive ataxia was Friedreich ataxia. The most frequent type of dominant hereditary spastic paraplegia in our sample was SPG4, and the most frequent recessive type was SPG7. CONCLUSIONS: In our sample, the estimated prevalence of ataxia and hereditary spastic paraplegia was 7.73 cases per 100 000 population. This rate is similar to those reported for other countries. Genetic diagnosis was not available in 47.6% of cases. Despite these limitations, our study provides useful data for estimating the necessary healthcare resources for these patients, raising awareness of these diseases, determining the most frequent causal mutations for local screening programmes, and promoting the development of clinical trials.

Practical recommendations for the clinical evaluation of patients with hereditary ataxia and hereditary spastic paraplegia.

Hereditary ataxia (HA) and hereditary spastic paraplegia (HSP) are rare diseases; as such, they are rarely managed in general neurology consultations. We present a set of brief, practical recommendations for the diagnosis and management of these patients, as well as a standardised procedure for comprehensive evaluation of disability. We provide definitions for HA and "HA plus," and "pure" and "complicated" HSP; describe the clinical assessment of these patients, indicating the main complementary tests and clinical scales for physical and psychological assessment of the patients; and summarise the available treatments. These recommendations are intended to facilitate daily neurological practice and to unify clinical criteria and disability assessment protocols for patients with HA and HSP.

[Analysis of two health attendance models for the non-hospital emergencies in Gipuzkoa: Retrospective study]. / Análisis de dos modelos asistenciales para la atención de las emergencias extrahospitalarias en Guipúzcoa: Estudio retrospectivo.

BACKGROUND AND OBJECTIVE: Out-of-hospital medical emergency services are defined as a functional organization that performs a set of sequential human and material activities. The objective of this study was to compare the mortality of patients attended by the out-of-hospital medical emergency services in 2 neighboring Spanish regions with different models of healthcare transport assistance for emergency care. MATERIAL AND METHOD: Retrospective observational cohort study, done between June 1, 2007 and December 31, 2008 in 2 regions of Gipuzkoa, Alto Deba (AD) and Bajo Deba (BD). The study variables were age, sex and place of exposure (AD/BD), heart rate, blood pressure, initial reason for the call defined by the European Resuscitation Council, unconsciousness and digestive bleeding. 3452 subjects were analyzed. RESULTS: The risk of in situ mortality in BD was 1.31 times higher than in AD (P=.050), that of hospital mortality in BD was 0.71 times lower than in AD (P=.011) and the risk of mortality at one year between counties and the combined mortality (in situ+hospital) did not contribute significant differences. CONCLUSIONS: Mortality (in situ+in-hospital, and one year aftercare) of patients treated by the out-of-hospital emergency medical services in AD (non-medicalized healthcare transport model) was similar to that of the BD region (mixed healthcare transport model).

[Incubation period of COVID-19: A systematic review and meta-analysis]. / Período de incubación de la COVID-19: revisión sistemática y metaanálisis.

BACKGROUND AND OBJECTIVE: The incubation period of COVID-19 helps to determine the optimal duration of the quarantine and inform predictive models of incidence curves. Several emerging studies have produced varying results; this systematic review aims to provide a more accurate estimate of the incubation period of COVID-19. METHODS: For this systematic review, a literature search was conducted using Pubmed, Scopus/EMBASE, and the Cochrane Library databases, covering all observational and experimental studies reporting the incubation period and published from 1 January 2020 to 21 March 2020.We estimated the mean and 95th percentile of the incubation period using meta-analysis, taking into account between-study heterogeneity, and the analysis with moderator variables. RESULTS: We included seven studies (n = 792) in the meta-analysis. The heterogeneity (I2 83.0%, p < 0.001) was significantly decreased when we included the study quality and the statistical model used as moderator variables (I2 15%). The mean incubation period ranged from 5.6 (95% CI: 5.2 to 6.0) to 6.7 days (95% CI: 6.0 to 7.4) according to the statistical model. The 95th percentile was 12.5 days when the mean age of patients was 60 years, increasing 1 day for every 10 years. CONCLUSION: Based on the published data reporting the incubation period of COVID-19, the mean time between exposure and onset of clinical symptoms depended on the statistical model used, and the 95th percentile depended on the mean age of the patients. It is advisable to record sex and age when collecting data in order to analyze possible differential patterns.

Incubation period of COVID-19: A systematic review and meta-analysis.

BACKGROUND AND OBJECTIVE: The incubation period of COVID-19 helps to determine the optimal duration of the quarantine and inform predictive models of incidence curves. Several emerging studies have produced varying results; this systematic review aims to provide a more accurate estimate of the incubation period of COVID-19. METHODS: For this systematic review, a literature search was conducted using Pubmed, Scopus/EMBASE, and the Cochrane Library databases, covering all observational and experimental studies reporting the incubation period and published from 1 January 2020 to 21 March 2020.We estimated the mean and 95th percentile of the incubation period using meta-analysis, taking into account between-study heterogeneity, and the analysis with moderator variables. RESULTS: We included seven studies (n=792) in the meta-analysis. The heterogeneity (I2 83.0%, p<0.001) was significantly decreased when we included the study quality and the statistical model used as moderator variables (I2 15%). The mean incubation period ranged from 5.6 (95% CI: 5.2-6.0) to 6.7 days (95% CI: 6.0-7.4) according to the statistical model. The 95th percentile was 12.5 days when the mean age of patients was 60 years, increasing 1 day for every 10 years. CONCLUSION: Based on the published data reporting the incubation period of COVID-19, the mean time between exposure and onset of clinical symptoms depended on the statistical model used, and the 95th percentile depended on the mean age of the patients. It is advisable to record sex and age when collecting data in order to analyze possible differential patterns.

Epidemiology of ataxia and hereditary spastic paraplegia in Spain: a cross-sectional study. / Mapa epidemiológico transversal de las ataxias y paraparesias espásticas hereditarias en España.

INTRODUCTION: Ataxia and hereditary spastic paraplegia are rare neurodegenerative syndromes. We aimed to determine the prevalence of these disorders in Spain in 2019. PATIENTS AND METHODS: We conducted a cross-sectional, multicentre, retrospective, descriptive study of patients with ataxia and hereditary spastic paraplegia in Spain between March 2018 and December 2019. RESULTS: We gathered data from a total of 1.809 patients from 11 autonomous communities, provided by 47 neurologists or geneticists. Mean (SD) age in our sample was 53.64 (20.51) years; 920 patients were men (50.8%) and 889 were women (49.2%). The genetic defect was unidentified in 920 patients (47.6%). A total of 1371 patients (70.9%) had ataxia and 562 (29.1%) had hereditary spastic paraplegia. Prevalence rates for ataxia and hereditary spastic paraplegia were estimated at 5.48 and 2.24 cases per 100 000 population, respectively. The most frequent type of dominant ataxia in our sample was SCA3, and the most frequent recessive ataxia was Friedreich ataxia. The most frequent type of dominant hereditary spastic paraplegia in our sample was SPG4, and the most frequent recessive type was SPG7. CONCLUSIONS: In our sample, the estimated prevalence of ataxia and hereditary spastic paraplegia was 7.73 cases per 100 000 population. This rate is similar to those reported for other countries. Genetic diagnosis was not available in 47.6% of cases. Despite these limitations, our study provides useful data for estimating the necessary healthcare resources for these patients, raising awareness of these diseases, determining the most frequent causal mutations for local screening programmes, and promoting the development of clinical trials.

Nanomechanical properties of surface-modified titanium alloys for biomedical applications.

The mechanical properties of the oxide layers developed at elevated temperature on three vanadium-free titanium alloys of interest for biomedical applications were investigated by means of the nanoindentation technique. The as-received alloys (Ti-13Nb-13Zr, Ti-15Zr-4Nb and Ti-7Nb-6Al) and their oxide scales formed by reaction with air at 750 degrees C for several oxidation times were analysed comparatively. In particular, the hardness and the Young's modulus exhibit larger values for the thermally oxidized alloys than for the untreated specimens. However, the Ti-7Nb-6Al alloy shows a different tendency to that of the TiNbZr alloys, which seems to be related to a different oxide layer growth as a function of the oxidation time.

Low Temperature Metal Free Growth of Graphene on Insulating Substrates by Plasma Assisted Chemical Vapor Deposition.

Direct growth of graphene films on dielectric substrates (quartz and silica) is reported, by means of remote electron cyclotron resonance plasma assisted chemical vapor deposition r-(ECR-CVD) at low temperature (650°C). Using a two step deposition process- nucleation and growth- by changing the partial pressure of the gas precursors at constant temperature, mostly monolayer continuous films, with grain sizes up to 500 nm are grown, exhibiting transmittance larger than 92% and sheet resistance as low as 900 Ω·sq-1. The grain size and nucleation density of the resulting graphene sheets can be controlled varying the deposition time and pressure. In additon, first-principles DFT-based calculations have been carried out in order to rationalize the oxygen reduction in the quartz surface experimentally observed. This method is easily scalable and avoids damaging and expensive transfer steps of graphene films, improving compatibility with current fabrication technologies.

Waning protection of influenza vaccination during four influenza seasons, 2011/2012 to 2014/2015.

BACKGROUND: Concerns have been raised about intraseasonal waning of the protection conferred by influenza vaccination. METHODS: During four influenza seasons, we consecutively recruited individuals aged 18years or older who had received seasonal influenza vaccine and were subsequently admitted to the hospital for influenza infection, asassessed by reverse transcription polymerase chain reaction. We estimated the adjusted odds ratio (aOR) of influenza infection by date of vaccination, defined by tertiles, as early, intermediate or late vaccination. We used a test-negative approach with early vaccination as reference to estimate the aOR of hospital admission with influenza among late vaccinees. We conducted sensitivity analyses by means of conditional logistic regression, Cox proportional hazards regression, and using days between vaccination and hospital admission rather than vaccination date. RESULTS: Among 3615 admitted vaccinees, 822 (23%) were positive for influenza. We observed a lower risk of influenza among late vaccinees during the 2011/2012 and 2014/2015A(H3N2)-dominant seasons: aOR=0.68 (95% CI: 0.47-1.00) and 0.69 (95% CI: 0.50-0.95). We found no differences in the risk of admission with influenza among late versus early vaccinees in the 2012/2013A(H1N1)pdm09-dominant or 2013/2014B/Yamagata lineage-dominant seasons: aOR=1.18 (95% CI: 0.58-2.41) and 0.98 (95% CI: 0.56-1.72). When we restricted our analysis to individuals aged 65years or older, we found a statistically significant lower risk of admission with influenza among late vaccinees during the 2011/2012 and 2014/2015A(H3N2)-dominant seasons: aOR=0.61 (95% CI: 0.41-0.91) and 0.69 (95% CI: 0.49-0.96). We observed 39% (95% CI: 9-59%) and 31% (95% CI: 5-50%) waning of vaccine effectiveness among participants aged 65years or older during the two A(H3N2)-dominant seasons. Similar results were obtained in the sensitivity analyses. CONCLUSION: Waning of vaccine protection was observed among individuals aged 65years old or over in two A(H3N2)-dominant influenza seasons.