Tailoring magnetic and mechanical properties of mesoporous single-phase Ni-Pt films by electrodeposition

Homogeneous mesoporous Ni-rich Ni-Pt thin films with adjustable composition have been synthesised by one-step micelle-assisted electrodeposition. The films exhibit a face-centred cubic solid solution (single phase) and their magnetic and mechanical properties can be tuned by varying the alloy composition. In particular, the Curie temperature (TC) is shown to decrease with the Pt content and thin films with a TC close to room temperature (i.e. Ni58Pt42) and below can be produced. Hysteresis loops show a decrease of saturation magnetisation (Ms) and coercivity (Hc) with decreasing Ni content. A comparison of porous and dense films reveals significantly lower saturation magnetic field strength for porous films. Concerning mechanical properties, mainly two trends can be observed: a decrease of the Young's modulus of the nanoporous films with respect to dense films by 10% in average and a progressive increase of Young's modulus with the Ni content from 4.2 GPa to 5.7 GPa in both types of films. The tunability of properties and facility of synthesis make this alloy a promising material for microelectromechanical systems (MEMS)

Treatment with tocilizumab or corticosteroids for COVID-19 patients with hyperinflammatory state: a multicentre cohort study (SAM-COVID-19)

Objectives: The objective of this study was to estimate the association between tocilizumab or corticosteroids and the risk of intubation or death in patients with coronavirus disease 19 (COVID-19) with a hyperinflammatory state according to clinical and laboratory parameters. Methods: A cohort study was performed in 60 Spanish hospitals including 778 patients with COVID-19 and clinical and laboratory data indicative of a hyperinflammatory state. Treatment was mainly with tocilizumab, an intermediate-high dose of corticosteroids (IHDC), a pulse dose of corticosteroids (PDC), combination therapy, or no treatment. Primary outcome was intubation or death; follow-up was 21 days. Propensity score-adjusted estimations using Cox regression (logistic regression if needed) were calculated. Propensity scores were used as confounders, matching variables and for the inverse probability of treatment weights (IPTWs). Results: In all, 88, 117, 78 and 151 patients treated with tocilizumab, IHDC, PDC, and combination therapy, respectively, were compared with 344 untreated patients. The primary endpoint occurred in 10 (11.4%), 27 (23.1%), 12 (15.4%), 40 (25.6%) and 69 (21.1%), respectively. The IPTW-based hazard ratios (odds ratio for combination therapy) for the primary endpoint were 0.32 (95%CI 0.22-0.47; p < 0.001) for tocilizumab, 0.82 (0.71-1.30; p 0.82) for IHDC, 0.61 (0.43-0.86; p 0.006) for PDC, and 1.17 (0.86-1.58; p 0.30) for combination therapy. Other applications of the propensity score provided similar results, but were not significant for PDC. Tocilizumab was also associated with lower hazard of death alone in IPTW analysis (0.07; 0.02-0.17; p < 0.001). Conclusions: Tocilizumab might be useful in COVID-19 patients with a hyperinflammatory state and should be prioritized for randomized trials in this situatio

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

Sin / Sense

Sexto desafío por la erradicación de la violencia contra las mujeres del Institut Universitari d’Estudis Feministes i de Gènere «Purificación Escribano» de la Universitat Jaume

Adelante / Endavant

Séptimo desafío por la erradicación de la violencia contra las mujeres del Institut Universitari d’Estudis Feministes i de Gènere "Purificación Escribano" de la Universitat Jaume

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Synthesis and magnetoelectric properties of Co-Pt based porous materials

La present tesi comprèn la síntesi electroquímica i l'estudi de les propietats magnetoelèctriques de materials porosos basats en cobalt-platí (Co-Pt). S'espera que aquests materials minimitzin la dissipació de calor i el consum d'energia en dispositius operats magnèticament. Atès que els efectes magnetoelèctrics són de naturalesa interficial, hom preveu que la porositat, la rugositat i la nanoestructuració en materials de base Co-Pt serveixin per incrementar la resposta magnetoelèctrica gràcies a l'augment de la relació superfície / volum. Per aquest motiu, es utilitzar l'electrodeposició a partir de solucions aquoses que contenien micel·les de P-123 (un procés denominat electrodeposició assistida per micel·les) per fabricar materials mesoporosos de Co-Pt formats per un aliatge de Co-Pt i òxids de Co (Co-Pt+CoxOy). Així mateix, s'ha combinat l'electrodeposició amb la fotolitografia i la deposició de capes atòmiques (DCA), per fabricar matrius de microestructures circulars i capes heteroestructurades, respectivament. Es van estudiar les propietats magnetoelèctriques d'aquests materials mitjançant l'ús d'electròlit com a material dielèctric, en un solvent orgànic polar i anhidre. A través d'aquest mètode s'aprofita la creació de la doble capa elèctrica per crear forts camps elèctrics a la interfície mostra/electròlit. En primer lloc, es va aconseguir reduir la coercitivitat (en un 88%) y augmentar el senyal Kerr (en un 60%) en sotmetre matrius de discs de diàmetre micromètric i mesoporosos de Co-Pt+CoxOy al camp elèctric a temperatura ambient. Les variacions induïdes pel voltatge es van atribuir a l'acumulació de càrrega a la superfície de les parets de porus ultraprimes dels microdiscs mesoporosos i a la migració d'ions oxigen assistida pel voltatge (és a dir, a efectes magneto-iònics). En segon lloc, es va aconseguir modular eficaçment la coercitivitat i el moment magnètic a saturació d'heteroestructures nanoestructurades de Co-Pt+CoxOy/HfOx i Co-Pt+CoxOy/AlOx en sotmetre-les a voltatges negatius i positius. Els canvis induïts pel camp elèctric es van poder explicar gràcies a la migració d'ions oxigen a través de la interfície Co-Pt+CoxOy/òxid DCA. En paral·lel, s'ha investigat l'impacte del processat de l'electròlit sobre la mesoporositat de capes metàl·liques de Co-Pt. Un estudi paramètric de diferents banys va servir per determinar que la dissolució prèvia de la salt d'hexacloroplanitat i el seu posterior emmagatzematge durant uns dies abans d'afegir la resta de reactius (la salt de cobalt i el surfactant polimèric de bloc P-123) són crucials per garantir la formació reproduïble de la xarxa mesoporosa. Finalment, es va dur a terme l'electrodeposició sobre substrats estampats amb cristalls col·loïdals per obtenir capes macroporoses magnèticament dures de Co-Pt. Les capes un cop dipositades mostraven un arranjament compacte de porus de 200 nm de diàmetre (comparable a la mida del diàmetre de les partícules col·loïdals) i, des del punt de vista estructural, estaven formades per una mescla de solucions sòlides de Co-Pt gairebé equiatòmiques (fase cúbica centrada a les cares A1 desordenada). Després d'un tractament tèrmic en buit, es va aconseguir transformar parcialment la fase A1 desordenada en l'ordenada tetragonal L10, cosa que provocà un increment notori de la coercitivitat del material de 148 Oe a 1328 Oe. Convé notar que la macroporositat de les capes es va poder preservar durant el tractament tèrmicLa presente Tesis doctoral abarca la síntesis electroquímica y la investigación de las propiedades magnetoeléctricas de materiales porosos basados en cobalto-platino (Co-Pt). Se espera que estos materiales minimicen la disipación de calor y el consumo de energía en dispositivos operados magnéticamente. Teniendo en cuenta la naturaleza interfacial de los efectos magnetoeléctricos, es de prever que la porosidad, la rugosidad y la nanoestructuración de los materiales basados en Co-Pt favorezcan o incrementen su respuesta magnetoeléctrica dada su elevada relación superficie/volumen. Por este motivo, en esta Tesis se ha empleado la electrodeposición a partir de soluciones acuosas que contenían micelas de P-123 (denominado electrodeposición asistida por micelas) para fabricar materiales mesoporosos a base de Co-Pt compuestos por una aleación de Co-Pt y óxidos de Co (Co-Pt+CoxOy). Asimismo, la electrodeposición se ha combinado con fotolitografía y deposición de capas atómicas (ALD) de HfOx y AlOx para la fabricación de matrices de microestructuras circulares y películas heteroestructuradas, respectivamente. Las propiedades magnetoeléctricas de los materiales se han estudiado mediante electrolito líquido como material dieléctrico, utilizando un solvente orgánico polar no acuoso. Este enfoque aprovecha la generación de una doble capa eléctrica para generar grandes campos eléctricos en la interfaz electrolito/muestra. En primer lugar, mediante la aplicación de campos eléctricos a discos mesoporosos de tamaño micrométrico de Co-Pt+CoxOy, se logró una reducción de la coercitividad (88%) y un aumento de la señal de Kerr (60%) a temperatura ambiente. Tales variaciones inducidas por el voltaje se atribuyeron a la acumulación de carga en la superficie de las paredes ultra-estrechas de los poros de los microdiscos mesoporosos, y a la migración de iones de oxígeno impulsada por el voltaje (es decir, a efectos magneto-iónicos). En un segundo trabajo, la coercitividad y el momento magnético en la saturación de heteroestructuras nanoestructuradas de Co-Pt+CoxOy/HfOx y Co-Pt+CoxOy/AlOx fueron modulados eficazmente después de polarizarlas con voltajes negativos y positivos. Los cambios inducidos por el voltaje se adscribieron a la migración de oxígeno en la interfaz Co-Pt+CoxOy/óxido. Paralelamente, se ha investigado el impacto del procesamiento del electrolito en la mesoporosidad en capas delgadas Co-Pt totalmente metálicas. Un estudio paramétrico de varios baños reveló que la disolución previa de la sal de hexacloroplatino y su posterior almacenamiento durante unos días, antes de que se añadan los demás reactivos químicos (la sal de cobalto y el surfactante polimérico de bloque P-123) es fundamental para la formación de la red mesoporosa. Finalmente, la electrodeposición en sustratos estampados con cristales coloidales se ha utilizado para la fabricación de películas macroporosas magnéticamente duras de Co-Pt. Las películas de Co-Pt mostraron una estructura empaquetada de poros de 200 nm de diámetros (coincidiendo con el tamaño de los coloides originales) y, estructuralmente, una mezcla de fases cristalográficas casi equiatómicas de solución solida de Co-Pt cúbica centrada en las caras (A1 desordenada). Tras el tratamiento térmico, se logró una transformación parcial de la fase desordenada cúbica A1 a la fase ordenada tetragonal L10 lo cual produjo un aumento significativo de la coercitividad de 148 Oe a 1328 Oe. Sorprendentemente, la porosidad de las películas se conservó después del tratamiento térmico.This Thesis dissertation focuses on the electrochemical synthesis and investigation of the magnetoelectric properties of cobalt-platinum (Co-Pt) based porous materials. These materials are expected to minimize heat dissipation and power consumption in magnetically actuated devices. Owing to the interfacial nature of magnetoelectric effects, porosity, roughness and nanostructuration in Co-Pt based materials are expected to promote or enhance their magnetoelectric response due to the increase in the surface-to-volume ratio. For this reason, electrodeposition from aqueous solutions containing P-123 micelle assemblies (referred to as micelle-assisted electrodeposition) was employed to fabricate mesoporous Co-Pt based materials consisting of Co-Pt alloy and Co oxides (Co-Pt+CoxOy). In combination with photolithography and the atomic layer deposition (ALD) of HfOx and AlOx nanolayers, arrays of circular microstructures and heterostructured films, respectively, were prepared. The magnetoelectric properties of the materials were studied by an electrolyte-gating approach in a polar, water-free, organic solvent. This approach exploits the generation of an electric double layer to create large electric fields at the electrolyte/sample interface. A reduction of coercivity (by 88%) and an increase of Kerr signal (by 60%) were obtained at room temperature when mesoporous Co-Pt+CoxOy arrays of micron-sized disks were subject to electric field. The observed voltage-induced variations were attributed to charge accumulation at the surface of the ultranarrow pore walls of the mesoporous microdisks and voltage-drive oxygen ion migration (i.e., magneto-ionic effects). In nanostructured Co-Pt+CoxOy/HfOx and Co-Pt+CoxOy/AlOx heterostructures, coercivity and magnetic moment at saturation were effectively modulated after biasing the heterostructured films with negative and positive voltages. The observed electric-field induced changes were ascribed to oxygen migration through the Co-Pt+CoxOy/ALD oxide interface. In parallel, the impact of electrolyte processing on the mesoporosity of fully metallic Co-Pt thin films was investigated. A parametric study using various baths revealed that previous dissolution of the hexachloroplatinate salt and their storage for a few days before the other chemicals (the cobalt salt and the P-123 block-copolymer surfactant) are added is critical for the reproducible formation of the mesoporous network. Finally, electrodeposition on colloidal crystal templated substrates was pursued to manufacture hard magnetic macroporous Co-Pt films. As-deposited films exhibited tightly packed pores of 200 nm in diameter (which matched the size of the parent colloids) and were structurally composed of a mixture of face-centered cubic A1-disordered nearly equiatomic Co‒Pt solid solutions. Upon annealing, partial transformation from A1-disordered into tetragonal L10-ordered phase was achieved, resulting in a significant increase of coercivity from 148 Oe to 1328 Oe. Remarkably, the macroporosity in the films was preserved after the thermal treatment

Electrolyte-gated magnetoelectric actuation: Phenomenology, materials, mechanisms, and prospective applications

Manipulation of the magnetic behavior of materials with voltage (i.e., magnetoelectric actuation) has become a topic of intense research during the last years. Apart from its obvious interest from a basic science standpoint, control and eventual switching of the magnetization without applying any external magnetic field (or spin polarized current) has the potential to drastically reduce the power consumption of magnetic devices due to the lack (or minimization) of Joule heating dissipation effects. Herein, an overview of the state-of-the-art of electrolyte-gated magnetoelectric actuation (where an electric field is applied using an electrolyte, either liquid or solid) is provided. The different types of mechanisms responsible for voltage-driven magnetic actuation (surface charging, ionic migration, also termed “magneto-ionics,” reduction/oxidation reactions, and ferroelectric/ferromagnetic coupling) are summarized. The various effects (changes in coercivity, anisotropy easy axis, exchange bias field, saturation magnetization, Curie temperature, etc.) observed in the different types of materials investigated so far (mainly metallic thin films and semiconductors, porous alloys, and nanocomposite structures) are described. The potential applications of electrolyte-gated magnetoelectric actuation in devices as well as the current challenges in the field are also reviewed with the aim of providing the basic ingredients for further prospects and technological advancements in this area

Lightweight macroporous Co-Pt electrodeposited films with semi-hard-magnetic properties

Macroporous, partially L10-ordered Co-Pt films with nearly equiatomic composition were successfully synthesized by electrodeposition from an aqueous sulfate–chloride electrolyte on colloidal crystal-templated substrates, followed by annealing in vacuum. The colloids deposited on the substrate consisted of amidine-functionalized polystyrene spheres of 215 ± 13 nm in diameter, which were self-assembled by electrophoresis. As-deposited Co-Pt films obtained after the removal of the spheres showed a highly-packed arrangement of macropores. Structurally, the films showed the A1-disordered face-centered cubic (fcc) Co-Pt solid solution, accompanied by small amounts of fcc/hexagonal close-packed (hcp)–Co. Upon annealing at 600 °C, the A1-disordered phase partly transformed into the L10-ordered (face-centered tetragonal, fct) phase. As a result, the coercivity significantly increased from 148 Oe to 1328 Oe. Importantly, the porosity of the films was preserved after annealing. Optimum annealing temperature and time were selected on the basis of a prior parametric study with electroplated dense counterparts. This work demonstrates that the combination of colloidal crystal templating and electrodeposition is a very convenient pathway towards lightweight semi-hard magnets with potential technological applications in automotive and aerospace industries, portable sensors or spectrometers, magnetic levitation systems, or magnetoelectric devices, among others.ISSN:0264-1275ISSN:1873-419

Study of carbon nanotube-rich impedimetric recognition electrode for ultra-low determination of polycyclic aromatic hydrocarbons in water

Carbon nanotubes (CNTs) have been studied as an electrochemical recognition element for the impedimetric determination of priority polycyclic aromatic hydrocarbons (PAHs) in water, using hexocyanoferrate as a redox probe. For this goal, an indium tin oxide (ITO) electrode functionalized with a silane-based self-assembled monolayer carrying CNTs has been engineered. The electroanalytical method, which is similar to an antibody-antigen assay, is straightforward and exploits the high CNT–PAH affinity obtained via π–interactions. After optimizing the experimental conditions, the resulting CNT-based impedimetric recognition platform exhibits ultra-low detection limits (1.75 ± 0.04 ng·L−1) for the sum of PAHs tested, which was also validated by using a certified reference PAH mixture.This work was funded by the ERC StG 2012-306826 e-GAMES. The authors also thank the DGI (Spain) project FANCY CTQ2016-80030-R, the Generalitat de Catalunya (2017-SGR-918) and the Spanish Ministry of Economy and Competitiveness, through the “Severo Ochoa” Programme for Centers of Excellence in R&D (SEV-2015-0496). Dr. J. Muñoz gratefully acknowledges the “Juan de la Cierva” programme.Peer reviewe