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1.
Water Res ; 169: 115210, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31670084

RESUMO

Developing efficient sunlight photocatalysts with enhanced photocorrosion resistance and minimal ecotoxicological effects on aquatic biota is critical to combat water contamination. Here, the role of chemical composition, architecture, and fixation on the ecotoxicological effects on microalgae of different ZnO and ZnO@ZnS based water decontamination photocatalysts was analyzed in depth. In particular, the ecotoxicological effects of films, nanoparticles and biomimetic micro/nano-ferns were carefully assessed by correlating the algae's viability to the Zn(II) release, the photocatalyst-microalgae interaction, and the production of reactive oxygen species (ROS). The results showed a drastic improvement in algal viability for supported ZnO@ZnS core@shell micro/nanoferns, as their ecotoxicity after 96 h light exposure was significantly lower (3.7-10.0% viability loss) compared to the ZnO films (18.4-35.5% loss), ZnO micro/nanoferns (28.5-53.5% loss), ZnO nanoparticles (48.3-91.7% loss) or ZnO@ZnS nanoparticles (8.6-19.2% loss) for catalysts concentrations ranging from 25 mg L-1 to 400 mg L-1. In particular, the ZnO@ZnS micro/nanoferns with a concentration of 400 mg L-1 exhibited excellent photocatalytic efficiency to mineralize a multi-pollutant solution (81.4 ±â€¯0.3% mineralization efficiency after 210 min under UV-filtered visible light irradiation) and minimal photocorrosion (<5% of photocatalyst dissolution after 96 h of UV-filtered visible light irradiation). Remarkably, the ZnO@ZnS micro/nanoferns showed lower loss of algal viability (9.8 ±â€¯1.1%) after 96 h of light exposure, with minimal reduction in microalgal biomass (9.1 ±â€¯1.0%), as well as in the quantity of chlorophyll-a (9.5 ±â€¯1.0%), carotenoids (8.6 ±â€¯0.9%) and phycocyanin (5.6 ±â€¯0.6%). Altogether, the optimized ZnO@ZnS core@shell micro/nanoferns represent excellent ecofriendly photocatalysts for water remediation in complex media, as they combine enhanced sunlight remediation efficiency, minimal adverse effects on biological microorganisms, high reusability and easy recyclability.


Assuntos
Nanoestruturas , Poluentes Químicos da Água , Óxido de Zinco , Biota , Catálise
2.
ACS Nano ; 13(7): 7716-7728, 2019 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-31173684

RESUMO

The physicochemical properties of spinel oxide magnetic nanoparticles depend critically on both their size and shape. In particular, spinel oxide nanocrystals with cubic morphology have shown superior properties in comparison to their spherical counterparts in a variety of fields, like, for example, biomedicine. Therefore, having an accurate control over the nanoparticle shape and size, while preserving the crystallinity, becomes crucial for many applications. However, despite the increasing interest in spinel oxide nanocubes there are relatively few studies on this morphology due to the difficulty to synthesize perfectly defined cubic nanostructures, especially below 20 nm. Here we present a rationally designed synthesis pathway based on the thermal decomposition of iron(III) acetylacetonate to obtain high quality nanocubes over a wide range of sizes. This pathway enables the synthesis of monodisperse Fe3O4 nanocubes with edge length in the 9-80 nm range, with excellent cubic morphology and high crystallinity by only minor adjustments in the synthesis parameters. The accurate size control provides evidence that even 1-2 nm size variations can be critical in determining the functional properties, for example, for improved nuclear magnetic resonance T2 contrast or enhanced magnetic hyperthermia. The rationale behind the changes introduced in the synthesis procedure (e.g., the use of three solvents or adding Na-oleate) is carefully discussed. The versatility of this synthesis route is demonstrated by expanding its capability to grow other spinel oxides such as Co-ferrites, Mn-ferrites, and Mn3O4 of different sizes. The simplicity and adaptability of this synthesis scheme may ease the development of complex oxide nanocubes for a wide variety of applications.

3.
ACS Appl Mater Interfaces ; 10(51): 44897-44905, 2018 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-30520631

RESUMO

A synergetic approach to enhance magnetoelectric effects (i.e., control of magnetism with voltage) and improve energy efficiency in magnetically actuated devices is presented. The investigated material consists of an ordered array of Co-Pt microdisks, in which nanoporosity and partial oxidation are introduced during the synthetic procedure to synergetically boost the effects of electric field. The microdisks are grown by electrodeposition from an electrolyte containing an amphiphilic polymeric surfactant. The bath formulation is designed to favor the incorporation of oxygen in the form of cobalt oxide. A pronounced reduction of coercivity (88%) and a remarkable increase of Kerr signal amplitude (60%) are observed at room temperature upon subjecting the microdisks to negative voltages through an electrical double layer. These large voltage-induced changes in the magnetic properties of the microdisks are due to (i) the high surface-area-to-volume ratio with ultranarrow pore walls (sub-10 nm) that promote enhanced electric charge accumulation and (ii) magneto-ionic effects, where voltage-driven O2- migration promotes a partial reduction of CoO to Co at room temperature. This simple and versatile procedure to fabricate patterned "nano-in-micro" magnetic motifs with adjustable voltage-driven magnetic properties is very appealing for energy-efficient magnetic recording systems and other magnetoelectronic devices.

4.
ACS Nano ; 12(10): 10291-10300, 2018 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-30256610

RESUMO

Electric-field-controlled magnetism can boost energy efficiency in widespread applications. However, technologically, this effect is facing important challenges: mechanical failure in strain-mediated piezoelectric/magnetostrictive devices, dearth of room-temperature multiferroics, or stringent thickness limitations in electrically charged metallic films. Voltage-driven ionic motion (magneto-ionics) circumvents most of these drawbacks while exhibiting interesting magnetoelectric phenomena. Nevertheless, magneto-ionics typically requires heat treatments and multicomponent heterostructures. Here we report on the electrolyte-gated and defect-mediated O and Co transport in a Co3O4 single layer which allows for room-temperature voltage-controlled ON-OFF ferromagnetism (magnetic switch) via internal reduction/oxidation processes. Negative voltages partially reduce Co3O4 to Co (ferromagnetism: ON), resulting in graded films including Co- and O-rich areas. Positive bias oxidizes Co back to Co3O4 (paramagnetism: OFF). This electric-field-induced atomic-scale reconfiguration process is compositionally, structurally, and magnetically reversible and self-sustained, since no oxygen source other than the Co3O4 itself is required. This process could lead to electric-field-controlled device concepts for spintronics.

5.
Nano Lett ; 18(9): 5854-5861, 2018 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-30165026

RESUMO

The atomic structure of nanoparticles can be easily determined by transmission electron microscopy. However, obtaining atomic-resolution chemical information about the individual atomic columns is a rather challenging endeavor. Here, crystalline monodispersed spinel Fe3O4/Mn3O4 core-shell nanoparticles have been thoroughly characterized in a high-resolution scanning transmission electron microscope. Electron energy-loss spectroscopy (EELS) measurements performed with atomic resolution allow the direct mapping of the Mn2+/Mn3+ ions in the shell and the Fe2+/Fe3+ in the core structure. This enables a precise understanding of the core-shell interface and of the cation distribution in the crystalline lattice of the nanoparticles. Considering how the different oxidation states of transition metals are reflected in EELS, two methods of performing a local evaluation of the cation inversion in spinel lattices are introduced. Both methods allow the determination of the inversion parameter in the iron oxide core and manganese oxide shell, as well as detecting spatial variations in this parameter, with atomic resolution. X-ray absorption measurements on the whole sample confirm the presence of cation inversion. These results present a significant advance toward a better correlation of the structural and functional properties of nanostructured spinel oxides.

6.
Adv Sci (Weinh) ; 5(8): 1800499, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30128259

RESUMO

Fe-Cu films with pseudo-ordered, hierarchical porosity are prepared by a simple, two-step procedure that combines colloidal templating (using sub-micrometer-sized polystyrene spheres) with electrodeposition. The porosity degree of these films, estimated by ellipsometry measurements, is as high as 65%. The resulting magnetic properties can be controlled at room temperature using an applied electric field generated through an electric double layer in an anhydrous electrolyte. This material shows a remarkable 25% voltage-driven coercivity reduction upon application of negative voltages, with excellent reversibility when a positive voltage is applied, and a short recovery time. The pronounced reduction of coercivity is mainly ascribed to electrostatic charge accumulation at the surface of the porous alloy, which occurs over a large fraction of the electrodeposited material due to its high surface-area-to-volume ratio. The emergence of a hierarchical porosity is found to be crucial because it promotes the infiltration of the electrolyte into the structure of the film. The observed effects make this material a promising candidate to boost energy efficiency in magnetoelectrically actuated devices.

7.
Small ; 14(30): e1800804, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29952138

RESUMO

Understanding the microstructure in heterostructured nanoparticles is crucial to harnessing their properties. Although microscopy is ideal for this purpose, it allows for the analysis of only a few nanoparticles. Thus, there is a need for structural methods that take the whole sample into account. Here, a novel bulk-approach based on the combined analysis of synchrotron X-ray powder diffraction with whole powder pattern modeling, Rietveld and pair distribution function is presented. The microstructural temporal evolution of FeO/Fe3 O4 core/shell nanocubes is studied at different time intervals. The results indicate that a two-phase approach (FeO and Fe3 O4 ) is not sufficient to successfully fit the data and two additional interface phases (FeO and Fe3 O4 ) are needed to obtain satisfactory fits, i.e., an onion-type structure. The analysis shows that the Fe3 O4 phases grow to some extent (≈1 nm) at the expense of the FeO core. Moreover, the FeO core progressively changes its stoichiometry to accommodate more oxygen. The temporal evolution of the parameters indicates that the structure of the FeO/Fe3 O4 nanocubes is rather stable, although the exact interface structure slightly evolves with time. This approach paves the way for average studies of interfaces in different kinds of heterostructured nanoparticles, particularly in cases where spectroscopic methods have some limitations.

8.
Rev. senol. patol. mamar. (Ed. impr.) ; 31(2): 47-53, abr.-jun. 2018. tab, graf
Artigo em Espanhol | IBECS | ID: ibc-176780

RESUMO

Introduccción: El objetivo es describir la validez diagnóstica y la seguridad de los métodos empleados en nuestro entorno para obviar el vaciamiento axilar en el tratamiento quirúrgico primario de mama en estadio inicial tras determinación de macrometástasis en el ganglio centinela. Métodos: Estudio observacional retrospectivo multicéntrico aprobado por el Comité de Ética. Determinación de sensibilidad, especificidad, valor predictivo positivo y negativo de los métodos: OSNA (punto de corte a 15.000 copias de ARN), score Tenon 5 (punto de corte en 5), perfil de alto riesgo (si no cumple T1G2RH+ HER-), criterios ACOSOG Z-11 y resultado de ganglio secundario. Se incluyó a pacientes con cáncer de mama dirigidas a tratamiento quirúrgico primario; tamaño T1-T2 y axila clínica y radiológicamente negativa; con resultado de ganglio centinela positivo para macrometástasis. Resultados: Se incluyó a 279 pacientes con macrometástasis en el ganglio centinela, de los cuales resultaron 69 (24,4%) linfadenectomías positivas. Los resultados de sensibilidad, especificidad, valor predictivo positivo y negativo fueron: OSNA (100%, 17%, 32%, 100%); Tenon 5 (91%, 34%, 31%, 92%); alto riesgo (82%, 32%, 28%, 85%), ACOSOG Z-11 (30%, 97%, 75%, 84%); ganglio secundario (86%, 76%, 55%, 94%). Conclusiones: El método más seguro, score Tenon 5, solo evitaría un tercio de linfadenectomías negativas. Un perfil de riesgo no ofrecería suficiente seguridad. La propuesta del grupo ACOSOG Z-11 sería el método menos seguro. La cuantificación de la macrometástasis por método OSNA no conseguiría validez diagnóstica. El análisis del ganglio secundario, siendo el método menos aplicado, sería el más válido, con mejor sensibilidad y especificidad conjunta. En nuestra valoración, ninguno de los métodos estudiados resultaría suficientemente riguroso pues no obtendrían resultados óptimos para permitir obviar la linfadenectomía


Introduction: The aim of this study was to describe the diagnostic validity and safety of the most commonly used methods to avoid axillary lymph node dissection (ALND) in the primary surgical treatment of initial-stage breast cancer after determination of sentinel node macrometastases. Methods: This multicenter, retrospective observational study was approved by the ethics committee and assessed the sensitivity, specificity, positive and negative predictive value of the following methods: OSNA (cut-off point of 15,000 RNA copies), Tenon 5 score (cut-off point 5), HIGH risk profile (RH+ HER-), ACOSOG Z-11 criteria and second-tier sentinel node outcome. We included patients with breast cancer undergoing primary surgical treatment, with T1-T2 tumours, clinically and radiologically negative axillae, and sentinel node macrometastases. Results: We included 279 patients, of whom 69 (24.4%) had a positive ALND. The results of sensitivity, specificity, positive predictive value and negative predictive value were as follows: OSNA (100%, 17%, 32%, 100%); Tenon 5 (91%, 34%, 31%, 92%); HIGH (82%, 32%, 28%, 85%), ACOSOG Z-11 (30%, 97%, 75%, 84%); SECOND (86%, 76%, 59%, 94%). Conclusions: The most accurate method, the Tenon score, would only avoid one-third of negative lymphadenectomies. Relying on a risk profile would not provide enough safety. The proposal of the ACOSOG Z-11 group was the least safe method. Quantification of macrometastases by OSNA would not be a valid diagnostic method. Second-tier sentinel node analysis, the least applied method, seems the most accurate, with the best sensitivity and specificity.In our analysis, none of the methods would be sufficiently rigorous to safely allow avoidance of ALND


Assuntos
Humanos , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/cirurgia , Excisão de Linfonodo/métodos , Linfonodo Sentinela/cirurgia , Neoplasias da Mama/patologia , Metástase Linfática/patologia , Estudos Retrospectivos
9.
Small ; 14(24): e1800868, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29761629

RESUMO

A crucial challenge in nanotherapies is achieving accurate and real-time control of the therapeutic action, which is particularly relevant in local thermal therapies to minimize healthy tissue damage and necrotic cell deaths. Here, a nanoheater/thermometry concept is presented based on magnetoplasmonic (Co/Au or Fe/Au) nanodomes that merge exceptionally efficient plasmonic heating and simultaneous highly sensitive detection of the temperature variations. The temperature detection is based on precise optical monitoring of the magnetic-induced rotation of the nanodomes in solution. It is shown that the phase lag between the optical signal and the driving magnetic field can be used to detect viscosity variations around the nanodomes with unprecedented accuracy (detection limit 0.0016 mPa s, i.e., 60-fold smaller than state-of-the-art plasmonic nanorheometers). This feature is exploited to monitor the viscosity reduction induced by optical heating in real-time, even in highly inhomogeneous cell dispersions. The magnetochromic nanoheater/thermometers show higher optical stability, much higher heating efficiency and similar temperature detection limits (0.05 °C) compared to state-of-the art luminescent nanothermometers. The technological interest is also boosted by the simpler and lower cost temperature detection system, and the cost effectiveness and scalability of the nanofabrication process, thereby highlighting the biomedical potential of this nanotechnology.

10.
Small ; 14(21): e1704396, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29667302

RESUMO

Voltage-driven manipulation of magnetism in electrodeposited 200 nm thick nanoporous single-phase solid solution Cu20 Ni80 (at%) alloy films (with sub 10 nm pore size) is accomplished by controlled reduction-oxidation (i.e., redox) processes in a protic solvent, namely 1 m NaOH aqueous solution. Owing to the selectivity of the electrochemical processes, the oxidation of the CuNi film mainly occurs on the Cu counterpart of the solid solution, resulting in a Ni-enriched alloy. As a consequence, the magnetic moment at saturation significantly increases (up to 33% enhancement with respect to the as-prepared sample), while only slight changes in coercivity are observed. Conversely, the reduction process brings Cu back to its metallic state and, remarkably, it becomes alloyed to Ni again. The reported phenomenon is fully reversible, thus allowing for the precise adjustment of the magnetic properties of this system through the sign and amplitude of the applied voltage.

11.
Small ; 14(15): e1703963, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29479814

RESUMO

Although cubic rock salt-CoO has been extensively studied, the magnetic properties of the main nanoscale CoO polymorphs (hexagonal wurtzite and cubic zinc blende structures) are rather poorly understood. Here, a detailed magnetic and neutron diffraction study on zinc blende and wurtzite CoO nanoparticles is presented. The zinc blende-CoO phase is antiferromagnetic with a 3rd type structure in a face-centered cubic lattice and a Néel temperature of TN (zinc-blende) ≈225 K. Wurtzite-CoO also presents an antiferromagnetic order, TN (wurtzite) ≈109 K, although much more complex, with a 2nd type order along the c-axis but an incommensurate order along the y-axis. Importantly, the overall magnetic properties are overwhelmed by the uncompensated spins, which confer the system a ferromagnetic-like behavior even at room temperature.

12.
Small ; 14(6)2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29323449

RESUMO

Nonlinear optical nanostructured materials are gaining increased interest as optical limiters for various applications, although many of them suffer from reduced efficiencies at high-light fluences due to photoinduced deterioration. The nonlinear optical properties of ferrite core/shell nanoparticles showing their robustness for ultrafast optical limiting applications are reported. At 100 fs ultrashort laser pulses the effective two-photon absorption (2PA) coefficient shows a nonmonotonic dependence on the shell thickness, with a maximum value obtained for thin shells. In view of the local electric field confinement, this indicates that core/shell is an advantageous morphology to improve the nonlinear optical parameters, exhibiting excellent optical limiting performance with effective 2PA coefficients in the range of 10-12 cm W-1 (100 fs excitation), and optical limiting threshold fluences in the range of 1.7 J cm-2 . These values are comparable to or better than most of the recently reported optical limiting materials. The quality of the open aperture Z-scan data recorded from repeat measurements at intensities as high as 35 TW cm-2 , indicates their considerably high optical damage thresholds in a toluene dispersion, ensuring their robustness in practical applications. Thus, the high photostability combined with the remarkable nonlinear optical properties makes these nanoparticles excellent candidates for ultrafast optical limiting applications.

13.
Small ; 13(11)2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28067997

RESUMO

The combination of lithography and ion implantation is demonstrated to be a suitable method to prepare lateral multilayers. A laterally, compositionally, and magnetically modulated microscale pattern consisting of alternating Co (1.6 µm wide) and Co-CoO (2.4 µm wide) lines has been obtained by oxygen ion implantation into a lithographically masked Au-sandwiched Co thin film. Magnetoresistance along the lines (i.e., current and applied magnetic field are parallel to the lines) reveals an effective positive giant magnetoresistance (GMR) behavior at room temperature. Conversely, anisotropic magnetoresistance and GMR contributions are distinguished at low temperature (i.e., 10 K) since the O-implanted areas become exchange coupled. This planar GMR is principally ascribed to the spatial modulation of coercivity in a spring-magnet-type configuration, which results in 180° Néel extrinsic domain walls at the Co/Co-CoO interfaces. The versatility, in terms of pattern size, morphology, and composition adjustment, of this method offers a unique route to fabricate planar systems for, among others, spintronic research and applications.

14.
ACS Appl Mater Interfaces ; 8(34): 22477-83, 2016 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-27502034

RESUMO

The exchange bias properties of Co/CoO coaxial core/shell nanowires were investigated with cooling and applied fields perpendicular to the wire axis. This configuration leads to unexpected exchange-bias effects. First, the magnetization value at high fields is found to depend on the field-cooling conditions. This effect arises from the competition between the magnetic anisotropy and the Zeeman energies for cooling fields perpendicular to the wire axis. This allows imprinting predefined magnetization states to the antiferromagnetic (AFM) shell, as corroborated by micromagnetic simulations. Second, the system exhibits a high-field magnetic irreversibility, leading to open hysteresis loops attributed to the AFM easy axis reorientation during the reversal (effect similar to athermal training). A distinct way to manipulate the high-field magnetization in exchange-biased systems, beyond the archetypical effects, was thus experimentally and theoretically demonstrated.

15.
Sci Rep ; 6: 30398, 2016 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-27462025

RESUMO

Spatio-temporal patterns are ubiquitous in different areas of materials science and biological systems. However, typically the motifs in these types of systems present a random distribution with many possible different structures. Herein, we demonstrate that controlled spatio-temporal patterns, with reproducible spiral-like shapes, can be obtained by electrodeposition of Co-In alloys inside a confined circular geometry (i.e., in disks that are commensurate with the typical size of the spatio-temporal features). These patterns are mainly of compositional nature, i.e., with virtually no topographic features. Interestingly, the local changes in composition lead to a periodic modulation of the physical (electric, magnetic and mechanical) properties. Namely, the Co-rich areas show higher saturation magnetization and electrical conductivity and are mechanically harder than the In-rich ones. Thus, this work reveals that confined electrodeposition of this binary system constitutes an effective procedure to attain template-free magnetic, electric and mechanical surface patterning with specific and reproducible shapes.


Assuntos
Ligas/química , Cobalto/química , Índio/química , Fenômenos Magnéticos , Periodicidade
16.
Nano Lett ; 16(8): 5068-73, 2016 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-27383904

RESUMO

The physicochemical properties used in numerous advanced nanostructured devices are directly controlled by the oxidation states of their constituents. In this work we combine electron energy-loss spectroscopy, blind source separation, and computed tomography to reconstruct in three dimensions the distribution of Fe(2+) and Fe(3+) ions in a FeO/Fe3O4 core/shell cube-shaped nanoparticle with nanometric resolution. The results highlight the sharpness of the interface between both oxides and provide an average shell thickness, core volume, and average cube edge length measurements in agreement with the magnetic characterization of the sample.

17.
ACS Appl Mater Interfaces ; 8(6): 4109-17, 2016 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-26804742

RESUMO

A new strategy to minimize magnetic interactions between nanowires (NWs) dispersed in a fluid is proposed. Such a strategy consists of preparing trisegmented NWs containing two antiparallel ferromagnetic segments with dissimilar coercivity separated by a nonmagnetic spacer. The trisegmented NWs exhibit a staircase-like hysteresis loop with tunable shape that depends on the relative length of the soft- and hard-magnetic segments and the respective values of saturation magnetization. Such NWs are prepared by electrodepositing CoPt/Cu/Ni in a polycarbonate (PC) membrane. The antiparallel alignment is set by applying suitable magnetic fields while the NWs are still embedded in the PC membrane. Analytic calculations are used to demonstrate that the interaction magnetic energy from fully compensated trisegmented NWs with antiparallel alignment is reduced compared to a single-component NW with the same length or the trisegmented NWs with the two ferromagnetic counterparts parallel to each other. The proposed approach is appealing for the use of magnetic NWs in certain biological or catalytic applications where the aggregation of NWs is detrimental for optimized performance.

18.
Rev. psiquiatr. salud ment ; 8(3): 130-136, jul.-sept. 2015. tab
Artigo em Espanhol | IBECS | ID: ibc-138606

RESUMO

Introducción. El trasplante es la opción terapéutica que ofrece mayor supervivencia y calidad de vida frente al fallo de un órgano. Los aspectos psiquiátricos y psicológicos de los candidatos a trasplante son relevantes, especialmente en la etapa de evaluación previa, pues la influencia de estos factores puede dificultar la evolución posquirúrgica, tanto en la supervivencia del órgano implantado como en la calidad de vida de la persona trasplantada. Son de especial importancia los factores vinculados a la patología por uso de sustancias, los trastornos psicopatológicos y el soporte psicosocial. Actualmente, existen pocas Guías que orienten sobre la correcta evaluación de los pacientes candidatos a estos procedimientos complejos. Método. Diecinueve psiquiatras y psicólogos clínicos de 6 hospitales públicos de Cataluña realizaron un trabajo sistemático de consenso para llegar al diseño de un protocolo unificado de evaluación psicológica y psiquiátrica. Se implementó un plan de trabajo anual, se definieron objetivos y se realizó una revisión bibliográfica, se discutieron los criterios de inclusión y exclusión, se seleccionaron los cuestionarios y se elaboró la entrevista estructurada. Resultados. Con el cumplimiento del plan de trabajo, se diseñó el Protocolo de Evaluación que se presenta en este artículo. Conclusiones. El trabajo sistematizado y la colaboración intercentros de psiquiatras y psicólogos clínicos ha facilitado homogeneizar y consensuar un protocolo unificado de evaluación (AU)


Introduction. Transplantation is the treatment option that offers improved survival and quality of life as compared to organ failure. Psychiatric and psychological aspects of transplant candidates are important, especially in the pre-assessment stage, as the influence of these factors can hinder post-surgical outcome in both the implanted organ survival and the quality of life of the transplanted person. Of particular importance, are the factors related to pathology due to substance use, psychopathology, and psychosocial support. There are currently few guidelines on the correct evaluation of patients eligible for these complex procedures. Method. Nineteen psychiatrists and clinical psychologists from six public hospitals in Catalonia conducted a systematic consensus to determine the design of a Unified Protocol psychological and psychiatric evaluation. An annual work plan was implemented, during which; the objectives were defined, a literature review was conducted, the inclusion and exclusion criteria were discussed, questionnaires were selected, and a structured interview was developed. Results. With the implementation of the work plan, the Assessment Protocol presented in this article was designed. Conclusions. systematic work and improving cooperation between psychiatrists and clinical psychologists, has led to homogeneity and consensus on a unified evaluation protocol (AU)


Assuntos
Feminino , Humanos , Masculino , Protocolos Clínicos/classificação , Protocolos Clínicos/normas , Testes Psicológicos/estatística & dados numéricos , Testes Psicológicos/normas , Transplante de Órgãos/métodos , Transplante de Órgãos/psicologia , Terapias Somáticas em Psiquiatria/métodos
19.
Phys Rev Lett ; 115(5): 057201, 2015 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-26274435

RESUMO

Thermal activation tends to destroy the magnetic stability of small magnetic nanoparticles, with crucial implications for ultrahigh density recording among other applications. Here we demonstrate that low-blocking-temperature ferromagnetic (FM) Co nanoparticles (T(B)<70 K) become magnetically stable above 400 K when embedded in a high-Néel-temperature antiferromagnetic (AFM) NiO matrix. The origin of this remarkable T(B) enhancement is due to a magnetic proximity effect between a thin CoO shell (with low Néel temperature, T(N), and high anisotropy, K(AFM)) surrounding the Co nanoparticles and the NiO matrix (with high T(N) but low K(AFM)). This proximity effect yields an effective antiferromagnet with an apparent T(N) beyond that of bulk CoO, and an enhanced anisotropy compared to NiO. In turn, the Co core FM moment is stabilized against thermal fluctuations via core-shell exchange-bias coupling, leading to the observed T(B) increase. Mean-field calculations provide a semiquantitative understanding of this magnetic-proximity stabilization mechanism.

20.
Nanoscale ; 7(21): 9878-85, 2015 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-25965577

RESUMO

Magnetic vortices have generated intense interest in recent years due to their unique reversal mechanisms, fascinating topological properties, and exciting potential applications. In addition, the exchange coupling of magnetic vortices to antiferromagnets has also been shown to lead to a range of novel phenomena and functionalities. Here we report a new magnetization reversal mode of magnetic vortices in exchange coupled Ir20Mn80/Fe20Ni80 microdots: distorted viscous vortex reversal. In contrast to the previously known or proposed reversal modes, the vortex is distorted close to the interface and viscously dragged due to the uncompensated spins of a thin antiferromagnet, which leads to unexpected asymmetries in the annihilation and nucleation fields. These results provide a deeper understanding of the physics of exchange coupled vortices and may also have important implications for applications involving exchange coupled nanostructures.

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